Aspen Flare System Analyzer Reference Guide

Transcription

Aspen Flare System Analyzer
Reference Manual
Version: V7.3
March 2011
Copyright (c) 1981-2011 by Aspen Technology, Inc. All rights reserved.
Aspen Flare System Analyzer, Aspen Flarenet, Aspen Plus, Aspen HYSYS, Aspen Plus Dynamics, and
the aspen leaf logo are trademarks or registered trademarks of Aspen Technology, Inc., Burlington,
MA. All other brand and product names are trademarks or registered trademarks of their respective
companies.
This document is intended as a guide to using AspenTech's software. This documentation contains
AspenTech proprietary and confidential information and may not be disclosed, used, or copied without
the prior consent of AspenTech or as set forth in the applicable license agreement. Users are solely
responsible for the proper use of the software and the application of the results obtained.
Although AspenTech has tested the software and reviewed the documentation, the sole warranty for
the software may be found in the applicable license agreement between AspenTech and the user.
ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH
RESPECT TO THIS DOCUMENTATION, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESS
FOR A PARTICULAR PURPOSE.
Aspen Technology, Inc.
200 Wheeler Road
Burlington, MA 01803-5501
USA
Phone: (781) 221-6400
Toll free: (888) 996-7001
Website http://www.aspentech.com
Contents
1 Introduction .........................................................................................................1
About this document.........................................................................................1
Audience .........................................................................................................1
Related Documentation .....................................................................................1
Technical Support ............................................................................................1
2 Components .........................................................................................................3
Overview.........................................................................................................3
Selecting Components ......................................................................................4
Component Types ..................................................................................4
Component List......................................................................................4
Matching the Name String .......................................................................5
Removing Selected Components ..............................................................5
Adding/Editing Components...............................................................................6
Add Hypothetical Component/Edit Component ...........................................6
Identification Tab ...................................................................................6
Critical Tab............................................................................................7
Other Tab..............................................................................................9
Editing Database Components .................................................................9
Estimating Unknown Properties .............................................................. 10
Organizing the Component List ........................................................................ 11
Changing the Components .................................................................... 11
Combining Components ........................................................................ 11
Binary Interaction Parameters ......................................................................... 11
3 Scenarios ...........................................................................................................15
Overview....................................................................................................... 15
Scenario Manager .......................................................................................... 16
Adding/Editing Scenarios................................................................................. 17
General Tab......................................................................................... 18
Constraints Tab.................................................................................... 19
Sources Tab ........................................................................................ 20
Estimates Tab ...................................................................................... 21
Scenario Tools ............................................................................................... 23
Adding Single Source Scenarios ............................................................. 23
4 Pipe Network......................................................................................................25
Overview....................................................................................................... 25
Pipe Manager................................................................................................. 25
Ignoring/Restoring Pipes ................................................................................. 26
Connections Tab .................................................................................. 27
Dimensions Tab ................................................................................... 29
Contents
i
Fittings Tab ......................................................................................... 30
Heat Transfer Tab ................................................................................ 32
Methods Tab........................................................................................ 33
Summary Tab ...................................................................................... 37
Multiple Editing .................................................................................... 38
Pipe Class Editor .................................................................................. 39
5 Nodes .................................................................................................................41
Overview....................................................................................................... 41
Node Manager ............................................................................................... 41
Ignoring/Restoring Nodes................................................................................ 42
Connection Nodes .......................................................................................... 43
Connector ........................................................................................... 43
Flow Bleed........................................................................................... 47
Horizontal Separator............................................................................. 50
Orifice Plate......................................................................................... 56
Tee .................................................................................................... 60
Vertical Separator ................................................................................ 65
Summary Tab ...................................................................................... 70
Boundary Nodes............................................................................................. 71
Control Valve ....................................................................................... 71
Relief Valve ......................................................................................... 81
Source Tools........................................................................................ 94
Flare Tip ............................................................................................. 95
6 Calculations......................................................................................................101
Starting the Calculations ............................................................................... 101
Efficient Modeling Techniques ........................................................................ 102
Data Entry......................................................................................... 102
Calculation Speed............................................................................... 103
Sizing Calculations ............................................................................. 104
7 Databases ........................................................................................................107
Overview..................................................................................................... 107
Database Features ....................................................................................... 108
Grid Controls ..................................................................................... 108
Maneuvering Through the Table ........................................................... 109
Printing............................................................................................. 109
Adding/Deleting Data.......................................................................... 109
Setting The Password ................................................................................... 110
Pipe Schedule Database Editor ....................................................................... 110
Fittings Database Editor ................................................................................ 112
Component Database Editor .......................................................................... 112
Importing Component Data ................................................................. 113
8 Automation ......................................................................................................115
Overview..................................................................................................... 115
Objects ....................................................................................................... 116
Object Hierarchy ................................................................................ 116
The Aspen Flare System Analyzer Type Library ...................................... 117
Object Browser .................................................................................. 117
ii
Contents
Automation Syntax............................................................................. 120
Examples: Accessing Aspen Flare System Analyzer Object Properties ....... 123
Aspen Flare System Analyzer Object Reference ................................................ 126
Application ........................................................................................ 127
Bleed ................................................................................................ 128
Bleeds .............................................................................................. 128
Component........................................................................................ 129
Components ...................................................................................... 130
Connector ......................................................................................... 130
Connectors ........................................................................................ 131
ControlValve...................................................................................... 132
ControlValves .................................................................................... 133
HorizontalSeparator............................................................................ 133
HorizontalSeparators .......................................................................... 134
Nodes ............................................................................................... 134
OrificePlate........................................................................................ 135
OrificePlates ...................................................................................... 135
Pipe.................................................................................................. 136
Pipes ................................................................................................ 138
ReliefValve ........................................................................................ 139
ReliefValves....................................................................................... 141
Scenario ........................................................................................... 141
Scenarios .......................................................................................... 142
Solver............................................................................................... 142
Tee .................................................................................................. 143
Tees ................................................................................................. 144
Tip ................................................................................................... 145
Tips .................................................................................................. 146
VerticalSeparator ............................................................................... 146
VerticalSeparators .............................................................................. 147
Example – Automation In Visual Basic ............................................................ 147
Updating Automation Files From Previous Versions ........................................... 155
9 Theoretical Basis ..............................................................................................157
Pressure Drop .............................................................................................. 157
Pipe Pressure Drop Method.................................................................. 157
Fittings Pressure Change Methods ........................................................ 165
Vapor-Liquid Equilibrium ............................................................................... 175
Compressible Gas............................................................................... 175
Vapor Pressure .................................................................................. 175
Soave Redlich Kwong.......................................................................... 176
Peng Robinson ................................................................................... 177
Physical Properties ....................................................................................... 178
Vapor Density .................................................................................... 178
Liquid Density.................................................................................... 178
Vapor Viscosity .................................................................................. 179
Liquid Viscosity .................................................................................. 179
Liquid Phase Mixing Rules for Viscosity.................................................. 181
Thermal Conductivity.......................................................................... 182
Enthalpy ........................................................................................... 182
Noise .......................................................................................................... 186
Contents
iii
A File Format.......................................................................................................189
Import/Export Details ................................................................................... 189
Process Descriptions ........................................................................... 189
Definition File Formats ........................................................................ 192
Recognized Objects and Items ............................................................. 197
Report Files Format ...................................................................................... 215
B References .......................................................................................................221
C Glossary of Terms ............................................................................................223
Adiabatic Flow ............................................................................................. 223
Choked Flow ................................................................................................ 223
Critical Pressure ........................................................................................... 223
Critical Temperature ..................................................................................... 223
Dongle........................................................................................................ 223
Equivalent Length ........................................................................................ 223
Isothermal Flow ........................................................................................... 224
MABP.......................................................................................................... 224
Mach Number .............................................................................................. 224
Node .......................................................................................................... 224
Reduced Pressure......................................................................................... 224
Reduced Temperature................................................................................... 224
Scenario ..................................................................................................... 224
Schedule ..................................................................................................... 225
Security Device ............................................................................................ 225
Source ........................................................................................................ 225
Static Pressure............................................................................................. 225
Tailpipe....................................................................................................... 225
Total Pressure.............................................................................................. 225
Velocity Pressure.......................................................................................... 225
Index ..................................................................................................................226
iv
Contents
1 Introduction
This section provides information on the following topics:

About this Document

Audience

Related Documentation

Technical Support
About this document
The guide provides a detailed description of all the features and functionality
within Aspen Flare System Analyzer (previously called Aspen FLARENET).
Audience
This guide is intended for process and process systems engineers.
Related Documentation
Title
Content
Getting Started Guide
Tutorials covering the basic use of Aspen
Flare System Analyzer
Technical Support
AspenTech customers with a valid license and software maintenance
agreement can register to access the online AspenTech Support Center at:
http://support.aspentech.com
This Web support site allows you to:
1 Introduction

Access current product documentation

Search for tech tips, solutions and frequently asked questions (FAQs)

Search for and download application examples
1

Search for and download service packs and product updates

Submit and track technical issues

Send suggestions

Report product defects

Review lists of known deficiencies and defects
Registered users can also subscribe to our Technical Support e-Bulletins.
These e-Bulletins are used to alert users to important technical support
information such as:

Technical advisories

Product updates and releases
Customer support is also available by phone, fax, and email. The most up-todate contact information is available at the AspenTech Support Center at
http://support.aspentech.com.
2
1 Introduction
2 Components

Overview

Selecting Components

Adding/Editing Components

Organizing the Component List

Binary Interaction Parameters
Overview
Data for all components that will be used in the simulation must be selected
before the sources are defined. These components may be taken from the
standard component library, or you may define your own components, known
as hypothetical components.
You may select components from Component Manager, which can be
accessed by clicking Components in the Build group on the Home tab of the
Ribbon.
The Component Manager window will be displayed:
2 Components
3
Fig 2.1
This view displays all of the Available Components and Selected
Components,, and provides various tools which you can use to add and edit
database and hypothetical components.
Selecting Components
Component Types
You may filter the list of available components to include only those belonging
to a specific family. All and None turn all of the filters on and off,
respectively, Invert toggles the status of each check box individually. As an
example, if only Hydrocarbons (HC) and Misc were selected, and you clicked
Invert,, then these two check boxes would be cleared, while the remaining
check boxes would be selected.
Component List
Components can be chosen from the Available Components list, and added
to the Selected C
Components list, using one of the following methods:
4
1
Arrow Keys – Use the arrow keys to move the highlight up or down one
component.
2
PageUp/PageDown - Press these keyboard keys to advance an entire
page forward or backward.
2 Components
3
Home/End - Press Home to move to the start of the list and End to
move to the end of the list.
4
Scroll Bar - Use the scroll bar to move up and down through the list.
Note: You can select multiple components by using the SHIFT or CTRL keys as
you select components.
5
Enter the component name from keyboard - When you type a letter
or number, you will move to the next component in the list which starts
with that character. If you repeatedly enter the same character, you will
cycle through all of the components which start with that character.
To add a component, you must first highlight it (by moving through the list
until that component is highlighted) and click to select, then transfer it by
double-clicking it or clicking Add.
Matching the Name String
The interpretation of your input is limited to the Component Types which
are checked.
Another way to add components is through the Selection Filter feature. The
Selection Filter box accepts keyboard input, and is used to locate the
component(s) in the current list that best matches your input.
You may use wildcard characters as follows:
? - Represents a single character.
* - Represents a group of characters of undefined length.
Any filter string has an implied * character at the end.
Some examples are shown here:
Filter
Result
methan
methanol, methane, etc.
*anol
methanol, ethanol, propanol, etc.
?-propanol
1-propanol, 2-propanol
*ane
methane, ethane, propane, i-butane, etc.
As you are typing into the Selection Filter box, the component list is
updated, matching what you have presently typed. You may not have to enter
the complete name or formula before it appears in the component list.
Removing Selected Components
You can remove any component from the Selected Components list:1
Highlight the component(s) you want to delete.
2
Click Remove.
You can select multiple components using Shift-click and Ctrl-click to remove
them all. Once the components are removed from the list, any source
compositions that used this component will be normalized.
2 Components
5
Adding/Editing Components
To create a new component (hypothetical), click Hypothetical.
Hypothetical Hypothetical
components are set up in th
the
e same manner as database components.
Previously defined hypothetical components can be changed by selecting
them in the Selected Component
Components list and clicking Edit.
Add Hypothetical Component/Edit
Component
Upon clicking either Hypothetical or Edit, the Component
mponent Editor opens up.
Identification Tab
The minimum data requirements for creating a component are specified here:
here
Fig 2.2
Component Types
6

Hydrocarbon ((HC)

Miscellaneous ((Misc)

Amine
2 Components

Alcohol

Ketone

Aldehyde

Ester

Carboxylic Acid (Carbacid)

Halogen

Nitrile

Phenol

Ether
The following fields are available on this tab:
Input Field
Description
Name
An alphanumeric name for the component (e.g. - Hypo -1).
Type
The type of component (or family) can be selected from the list
provided. There is a wide selection of families to choose from, which
allows better estimation methods to be chosen for that component.
ID
The ID number is provided automatically for new components and
cannot be edited.
Mol. Wt.
The molecular weight of the component.
NBP
The normal boiling point of the component.
Std. Density
The density of the component as liquid at 1 atm and 60 F.
Watson K
The Watson characterization factor.
Critical Tab
Critical properties are specified here.
2 Components
7
Fig 2.3
The following field
fields are available on this tab:
8
Input Field
Description
Critical Pres.
The critical pressure of the component. If the component
represents more than a single real component, the pseudo
critical pressure should be used.
Critical Temp.
The critical temperature
e of the component. If the component
critical temperature should be used.
Critical Volume
The critical volume of the component. If the component
pse
critical volume should be used.
Char. Volume
The characteristic volume of the component. If the component
characteristic volume should be used.
Acentric Factor
The acentric factor of the component.
Acent. Fact. (SRK)
The Soave-Redlich-Kwong
Kwong acentric factor of the component
(also called the COSTALD Acentricity).
2 Components
Other Tab
Coefficients for the polynomial equations for the prediction of Ideal Gas
thermodynamic properties and parameters for the vi
viscosity
scosity calculations are
specified here:
Fig 2.4
Input Field
Description
Hi A, Hi B, Hi C, Hi D, Hi E, and
Hi F
The coefficients for the ideal gas specific enthalpy
equation:
H = A + BT + CT2 + DT3 + ET4 + FT5
i
Entropy Coef.
The coefficient
nt for the entropy equation.
Viscosity A and Viscosity B
Viscosity coefficients used in the NBS Method (Ely
and Hanley, 1983).
Editing Database Components
If you want to change the data for one of the database components, e.g.
Methane, you will find that opening the Component Editor for this
component will display read-only values that cannot be changed.
2 Components
9
Fig 2.5
In order to update the data for a database component it must first be
changed to a hypothetical comp
component.
At the very minimum, you need to specify the Molecular Weight. However, it
is a good practice to specify at least two of the following properties:

Molecular Weight ((Mol. Wt.)

Normal Boiling Point ((NBP)

Standard Density ((Std. Density)
This is done by clicking Hypothetical in the Component Editor.
Editor
Estimating Unknown Properties
If any of the above data is unknown, click Estimate to fill-in
in the unknown
properties.
Supply as many properties as are known, so that the estimation can be as
accurate as possible.
10
2 Components
Organizing the Component List
The Selected Components list can be organized in the following different
ways.
Changing the Components
You can switch the components in the Selected Components list with the
ones in the Available Components list while maintaining the source mole
fractions.
In Component Manager, select the components in both the Selected
Components and the Available Components lists. Click Switch to switch
the two components.
Combining Components
Multiple components can be combined and represented by a single component
to reduce the number of components in the model.
To combine multiple components:
1
Select the components you want to combine by Ctrl-clicking them in the
Selected Components list.
2
Click Combine.
The Component Combination window will be displayed, and ask you to
select which basis should be used. The highlighted component in the box
at the upper part of the window is the target component to combine your
selected components into. Once the basis has been selected the combined
components will update each source in the model by summing the
composition of all of the combined components and assigning it to the
target component.
Reducing the number of components in this way is useful since it can greatly
speed the calculations. This is especially true where a model contains sources
defined with a long list of hypothetical components.
For example, consider a model containing the hypothetical components
BP200, BP225, BP250, BP275, BP300 boiling at 200°C, 225°C, 250°C, 275°C
and 300°C respectively. Since these components are likely to stay in the
liquid phase throughout the flare system, they may be combined into a single
component, BP250 without significant loss of accuracy. As another example,
in a purely gas phase flare system it is possible to combine isomers such as iButane and n-Butane into a single component n-Butane without
compromising results.
Binary Interaction Parameters
Binary Interaction Coefficients, often known as KIJ’s, are factors that are used
in equations of state to better fit the interaction between pairs of components
and hence improve the accuracy of VLE calculations. You are allowed to
specify binary interaction parameters for the Peng Robinson and Soave
2 Components
11
Redlich Kwong VLE methods or to estimate them through the Binary Coeffs
tab of the Component Manager as shown here.
Fig 2.6
To define binary interaction coefficients
coefficients, first select either the Peng
Robinson or Soave Redlich Kwong VLE method from the VLE Method list
at the top of the window.
Note: Binary interac
interaction
tion coefficients are not used by either the
Compressible Gas or Vapor Pressure VLE methods at present.
present
Individual binary interaction parameters are set by selecting the required
entry in the matrix and typing in the new value.
Note: The matrix is symmetri
symmetrical i.e. KJI is the same value as KJI, and updating
an entry will also update the corresponding entry in the table. E.g. updating
the entry in the Methane column, Propane row will also update the entry in
the Propane column, Methane row.
Individual binary interaction parameters may be estimated by selecting the
required entry in the matrix and clicking Estimate HC.. The estimation
method is based on the components
components' boiling point, standard liquid density and
critical volume.
It is possible to set several bina
binary
ry interaction parameters at the same time
either by Ctrl-clicking
clicking the two corners of a rectangular area in the matrix. The
selected entries can then be estimated by clicking Estimate HC or set to 0.0
by clicking Zero HC
HC-HC.
12
2 Components
Clicking Reset All causes all interaction parameters to be set to their default
values. Generally this is 0.0 for hydrocarbon components with non zero
values being supplied only for common polar components.
If the Auto Estimate check box is selected, then the interaction parameters
for new components are automatically estimated as they are added to the
model.
2 Components
13
14
2 Components
3 Scenarios

Overview

Scenario Manager

Adding/Editing Scenarios

Scenario Tools
Overview
A scenario defines a set of source conditions (flows, compositions, pressures
and temperatures) for the entire network. The design of a typical flare header
system will be comprised of many scenarios for each of which the header
system must have adequate hydraulic capacity. Typical scenarios might
correspond to:

Plant wide power failure

Plant wide cooling medium or instrument air failure

Localized control valve failure

Localized fire or Depressurization
The scenario management allows you to simultaneously design and rate the
header system for all of the possible relief scenarios.
Note: Although the major relief scenarios will normally constrain the size of
the main headers, care should be taken in the evaluation of velocities in the
individual relief valve tailpipes and sub headers. When looking at relief valves
which might operate alone, lower back pressures in the main headers may
lead to localized high velocities and consequently choked flow in the tail pipes.
As well as having different source conditions, each scenario can have unique
design limitations that will be used either to size the pipes or to highlight
problems when an existing flare system is being rated. For example, a Mach
number limit of 0.30 might be applied for normal flaring compared to a Mach
number limit of 0.50 or greater at the peak flows encountered during plant
blowdown.
3 Scenarios
15
Scenario Manager
Scenarios can also be selected by selecting the scenario from the list in Run
group on the Home tab of the Ribbon.
Fig 3.1
Scenarios are managed via the Scenario Manager. This window allows you
to add, edit or delete scenarios as well as to select the current scenario for
which scenario specific data is displayed. All cases have at least one scenario.
To access the Scenario Manager
On the Home tab, in Build, click Scenarios.
Scenario Manager will be displayed:
16
3 Scenarios
Fig 3.2
The Scenario Manager displays all scenarios in the case, and indicates the
current scenario. Several buttons are available:
Button
Description
Clone
Clones
es the highlighted scenario and adds a new scenario to
the Scenarios list.
Edit
Edits the highlighted scenario.
Delete
Removes the currently highlighted scenario. There must
always be at least one scenario in the case.
Current
To make a scenario the current
rent one, highlight the appropriate
scenario, and then click Current.
Close
Closes the Scenario Manager.
Adding/Editing Scenarios
Aspen Flare System Analyzer has no pre
pre-programmed
programmed limits on the number of
scenarios which can be defined within a single case.
To add a scenario, highlight a existing scenario in the Scenarios list, and
then click Clone in the Scenario Manager.
To edit a scenario, highlight it, and then click Edit.
The Scenario Editor will be displayed.
3 Scenarios
17
General Tab
You may provide the following information on the General tab:
Fig 3.3
18
Data
Description
Name
An alphanumeric description of the scenario (e.g. Power
Failure).
System Back Pres
Pres.
The system back pressure at the Flare Tip
ip exit. This
Thi will
normally be atmospheric pressure, but can be set to represent
system design conditions at the exit point. If left empty, the
value on the Calculation Options Editor will be used. The
minimum value is 0.01 bar (absolute pressure).
3 Scenarios
Constraints Tab
This
is tab requires the following information for both headers and tailpipes.
Fig 3.4
Tailpipes are indicated by the Tailpipe field on the Connections box of the
Pipe Editor.. You may provide different design information ((Mach
Mach Number,
Number
Noise at 1 m, Vapor Vel
Velocity, Liquid Velocity) for the Headers and
Tailpipes.. Any boxes may be left empty, in which case they will be ignored.
3 Scenarios
Data
Description
Mach Number
The maximum allowable Mach number for all pipe segments.
Calculated values that exceed this number will be
e highlighted in the
results.
Vapor Velocity
The maximum allowable vapor velocity. Calculated velocities that
exceed this value will be indicated in the results.
Liquid Velocity
The maximum allowable liquid velocity. Calculated velocities that
exceed this value will be indicated in the results.
19
Rho V2
The density times the velocity square. This value is normally used
as a limiting factor to prevent erosion.
Noise
The maximum allowable sound pressure level at a distance of 1
meter for all pipe segments. This is an average value over the
length of the pipe. Calculated values that exceed this specification
will be highlighted in the results.
Check Vel.
Constraint
Specify either Mixture Velocity or Phase Superficial Velocity is
used while checking the velocity constraints for design in a
scenario.
Note: Whilst rating the network you may define a Mach number constraint of
1.00, in order to highlight only choked flow conditions. This is not
recommended for design calculations where a more reasonable value such as
0.5 or 0.7 will lead to a more rapid solution towards the maximum allowable
back pressure constraints.
Sources Tab
If a source is ignored, the MABP constraint is ignored by sizing calculations.
When you select the Sources tab, you will see that all sources are displayed
on this tab.
Note: If you are setting up a new case, the Sources tab will not show any
sources.
20
3 Scenarios
Fig 3.5
This tab is useful in that you can easily toggle whether or not individual
sources are to be included in the current scenario, without having to either
unnecessarily delete sources or set the flow of a source to zero.
Estimates Tab
The Estimates tab allows some control over the selection and initialization of
flowrates for pipes which are to be used as tears in the solution of looped
loo
systems. The use to which each field is put is dependent upon the Structure
Analyzer setting on the Solver tab of Calculation Options Editor.
Editor
The check boxes in the No Tear column of the table allow you to prevent
pipes from being used as tears - selectt the check box to prevent a pipe from
being used as a tear or clear it to allow it. This setting has no effect if the
Simultaneous structural analyzer is used.
When the Convergent structural analyzer is used, the Molar Flow column
recommends a tear locati
location
on and initial value for the flow at the tear location.
If the structural analyzer does find that the pipe may be a valid tear location,
location
then this value is ignored.
3 Scenarios
21
When the Simultaneous structural analyzer is used, the Molar Flow column
is used to seed th
the
e analyzer. This value will always impact the initialization as
long as the structural analysis succeeds but the pipe will not necessarily be
selected as a tear pipe. In the event that the structural analysis fails with any
Molar Flow estimates
estimates, the model will be initialized by the default values.
Fig 3.6
Since the Simultaneous structural analyzer generally offers better
performance than the Convergent analyzer it will rarely be necessary to
specify information on the Estimates tab other than for the purpose
pur
of
improving the speed of convergence of the model. In the event that a model
proves problematic to converge, a number of additional columns are available
to tune the convergence algorithms. These may be exposed by stretching the
view horizontally.
The Max. Step column defines the maximum change to the flow in a tear
pipe over a single iteration whilst the Max. Flow and Min. Flow columns
constrain the flow in a tear pipe. Not all these values are used by all the Loop
Solver algorithms.
22
3 Scenarios
Max. Step
Max. Flow
Min. Flow
Newton-Raphson
3
3
3
Broyden
3
3
3
Force Convergent
Conjugate Gradient Minimisation
Quasi-Newton Minimization
Scenario Tools
The complete analysis of a flare system should ideally include analysis of the
system for the scenarios in which each source relieves on its own. For a large
network with many sources, it can become tedious to define each of these
scenarios. These can automatically be added to your model as follows.
Adding Single Source Scenarios
Click Source Tools from the Tools group on the Home tab of the Ribbon,
then select Add Single Source Scenarios or use the hot key combination
Alt, H, U, A. Click OK for the message that pops up.
This will analyze your model and add a scenario for each source that has a
non-zero flow rate defined in at least one scenario. Source data will be copied
from the scenario in which it has the highest flow rate.
3 Scenarios
23
24
3 Scenarios
4 Pipe Network

Overview

Pipe Manager

Ignoring/Restoring Pipes

Multiple Editing
Overview
The pipe network comprises a series of interconnected pipes. These pipes can
be added, edited and deleted from the Pipe Manager.
Pipe Manager
To access the Pipe Manager, click Pipes in the Build group on the Home
tab of the Ribbon.
4 Pipe Network
25
Fig 4.1
The following buttons are available:
Button
Description
Add
Adds a new pipe segment. This new pipe will be named with a number
depending upon the number of pipes already ad
added.
Edit
Edits the currently highlighted pipe segment.
Delete
Removes the currently highlighted pipe segment.
Close
Closes the Pipe Manager.
Ignoring/Restoring Pipes
When you ignore a single pipe, all upstream pipes are automatically ignored.
You can ignore single or multiple pipes within the model. When you ignore a
single pipe, all upstream nodes are automatically ignored. This enables you to
do what if type calculations, where part of the network can be excluded from
the calculation without the need for deletion and reinstallation of the
appropriate nodes.
To ignore a pipe:
26
1
Open the Pipe Editor window of the pipe that you want to ignore.
2
On the Connections tab, select the Ignore check box.
4 Pipe Network
Fig 4.2
To restore a pipe that has previously been ignored:
1
Open the Pipe Editor window of the pipe that you want to restore.
2
On the Connections tab, clear the Ignore check box.
Connections Tab
The name of the pipe segment and connectivity information is specified here.
4 Pipe Network
27
Fig 4.3
28
Input Data
Description
Name
An alphanumeric description of the pipe segment.
Location
An alphanu
alphanumeric
meric description of the location within the plant for the
segment.
Upstream
Node
This is the name of the node upstream of the pipe. The list allows
you to select from a list of existing unconnected nodes in the model.
Downstream
Node
This is the name of the node upstream of the pipe. The list allows
you to select from a list of existing unconnected nodes in the model.
Tailpipe
This list allows you to select whether the pipe should be treated as a
tailpipe. If set to Yes and the Rated Flow for Tailpipes
Tailpip
calculation
option is selected in the Calculation Options dialog box, the
pressure drop for this pipe will be calculated using the rated flow in
place of the relieving flow rate.
Ignore
This check box may be selected to remove the pipe from
calculation
calculations
s temporarily. When selected the pipe and all upstream
nodes and pipes will be ignored during calculations.
Fitting Loss
The fitting loss for the pipe segment. You cannot change the value
shown in this box. Instead, calculated value on the Fittings tab can
be updated by clicking Link or Paste.
4 Pipe Network
You have the option of modeling a pipe segment as a main header or a
tailpipe. The ability to classify a pipe as either a tailpipe or a header allows
you to perform calculations in which the pressure drop for tailpipes
tailpi
is
determined by the rated flow and that for headers is determined by the
nominal flow. This is in accordance with API
API-RP-521.
In the Scenario Editor
Editor, you can set design limits for the Mach Number,
Number
Vapor and Liquid Velocities
Velocities, Rho V2 and Noise separately
ly for the main
headers and the tailpipes.
Dimensions Tab
The physical dimensions and characteristics of the pipe segment are specified
here.
Fig 4.4
4 Pipe Network
Input Data
Description
Length
The physical length of the pipe segment. This length is used in
association with the fittings loss coefficients to calculate the
equivalent length of the pipe. If you have equivalent length data
for your network, enter this data here as the sum of the actual
29
Input Data
Description
length plus the equivalent length of the fittings and enter zero for
the fittings loss coefficients.
Elevation Change
A positive elevation indicates that the outlet is higher than the
inlet.
Material
The pipe material, either Carbon Steel or Stainless Steel.
Roughness
The surface roughness of the pipe segment. Whenever a material
is selected, the absolute roughness is initialized to the default
value for the material as defined on the Preferences view.
Thermal
Conductivity
The thermal conductivity of the pipe wall. This is used by the
heat transfer calculations when these are enabled.
Nominal
Diameter
The nominal pipe diameter used to describe the pipe size. For
pipes with a nominal diameter of 14 inches or more, this will be
the same as the outside diameter of the pipe.
Schedule
Select a schedule number from the list, you will be able to select
a nominal pipe diameter from the pipe databases. It will not be
necessary to specify the Internal Diameter or the Wall
Thickness for the pipe.
Internal
Diameter
The pipe diameter used for the pressure drop calculations.
Wall Thickness
The thickness of the pipe wall. Valid values are any positive
number or zero.
Use Class
Select Yes to restrict the pipe sizes to those defined by the Pipe
Class.
Sizeable
If you wish the pipe segment to be resized by sizing calculations,
Yes should be selected. For example, a model of a network
containing a representation of the knockout drum, as a pipe
segment would normally leave this unchecked such that sizing
calculations for the pipes would not change the knockout drum
size.
Schedule Numbers
Carbon Steel:
10, 20, 30, 40, 60, 80, 100, 120, 140, 160, STD, XS, XXS, User
Stainless Steel:
5S, 10S, 40S, 80S
Fittings Tab
A list of pipe fittings may be added to the pipe segment. These fittings will be
modeled as an additional equivalent length applied linearly over the physical
length of the pipe segment.
30
4 Pipe Network
Fig 4.5
Input Data
Description
Length
Multiplier
The length of the pipe is multiplied by this value
ue to determine the
equivalent length used for the pressure drop calculation. If left
blank then the value on the Calculation Options Editor is used.
This option is useful for making an allowance for bends and other
fittings if these are not known.
Fittings Loss
The fittings "K" factor is calculated from the following equation in
which Ft is the friction factor for fully developed turbulent flow:
K = A + BFt
From the Database Fitting
Fittings list, select the appropriate type of fitting, and
then click Add to m
move the selection to the Selected Fittings
s list. You can
select as many fittings as required. The final fitting loss equation, which will
be a sum of all the selected fittings, will appear in a display field underneath
the Selected Fitting
Fittings list.
Click Link to transfer the coefficients for this equation into the Fittings Loss
field on the Connections tab,, while maintaining the list of fittings.
Click Paste to transfer the coefficients for the fitting equation into the
Fittings Loss field
field. The selected list of fittings will not be retained.
To remove the selected fitting individually, select the fitting and click Delete.
4 Pipe Network
31
Note: The network cannot be sized correctly if you specify equivalent length
data to model fittings losses, since the equivalent length of a
any
ny pipe fitting is
a function of the pipe diameter and will therefore be incorrect when the
diameters change.
Heat Transfer Tab
The pipe segment may perform calculations taking into account heat transfer
with the external air.
Fig 4.6
The following field
fields are available on this tab:
Input Data
Description
External Conditions Group
32
External Medium
Select the external medium. Two options are
currently available: Air or Sea Water.
Water
Temperature
Enter the temperature of the external air. If this field
is left blank, the global value set via the Calculation
Options Editor is used.
4 Pipe Network
Input Data
Description
External Medium Velocity
Enter the velocity of the external medium. If this field
is left blank, the global value set via the Calculation
Options Editor is used.
Heat Transfer Enabled
This list selects whether heat transfer calculations are
to be performed for the pipe. Furthermore, setting
only enables heat transfer calculations if the Enable
Heat Transfer option is also selected in the
Calculation Options Editor.
External Radiative HTC
This list selects whether or not the external radiative
heat transfer coefficient is included within the heat
transfer calculations.
Emissivity
Enter the fractional Emissivity to be used for
radiative heat transfer calculations.
Multiple Element Calculation
This list selects whether the heat transfer calculation
is done using a single element or the same number of
elements as the pressure drop calculation. If Yes is
selected, the heat transfer calculation sues the same
number of elements as the pressure drop calculation
Insulation Group
Description
A brief description to identify the type of pipe
insulation.
Thickness
Supply the insulation thickness.
Thermal Conductivity
Enter the insulation thermal conductivity.
Heating Group
Outlet Temp
You can explicitly set an outlet temperature for this
segment, or leave it blank. A heater in a flare
knockout drum is an example of process equipment
that may require a fixed outlet temperature.
Duty
Enter the heating duty and the outlet temperature
will be calculated based on the inlet temperature and
the defined duty.
Methods Tab
Calculation methods are specified here.
4 Pipe Network
33
Fig 4.7
Input Field
Description
VLE Method Group
VLE Method
34
The options for the Va
Vapor-Liquid
Liquid Equilibrium calculations are as
follows (see Chapter 9 Theoretical Basis for more details):

Compressible Gas - Real Gas relationship. This is only
available when the Enthalpy Method on the Calculation
Options Editor is Ideal Gas.

Peng Robinson - Peng Robinson Equation of State.
State This is
Options Editor is NOT Ideal Gas.

Soave Redlich Kwong - Soave Redlich Kwong Equation of
State. This is available when the Enthalpy Method on the
Calculation Options Editor is NOT Ideal Gas.
Gas

Vapor Pressure - Vapor Pressure method as described in API
Technical Data Book Volume 113. This is available when the
Enthalpy Method on the Calculation Options Editor is
NOT Ideal Gas.

Model Default - If this is selected, the Default method for the
VLE method (as defined on the Calculation Options Editor)
Editor
will be used.
4 Pipe Network
Input Field
Description
Pressure Drop Group
Horizontal
and Inclined
Pipes
4 Pipe Network
The Horizontal/Inclined methods apply only when you have
selected Two-Phase pressure drop. The options are:

Isothermal Gas - This is a compressible gas method that
assumes isothermal expansion of the gas as it passes along
the pipe. Aspen Flare System Analyzer uses averaged
properties of the fluid over the length of the pipe. The outlet
temperature from the pipe is calculated by adiabatic heat
balance either with or without heat transfer. Pressure losses
due to change in elevation are ignored.

Adiabatic Gas - This is a compressible gas method that
assumes adiabatic expansion of the gas as it passes along the
pipe. As with the Isothermal Gas method, pressure losses due
to changes in elevation are ignored.

Beggs & Brill - The Beggs and Brill method is based on work
done with an air-water mixture at many different conditions,
and is applicable for inclined flow.

Dukler - Dukler breaks the pressure drop in two-phase
systems into three components - friction, elevation and
acceleration. Each component is evaluated independently and
added algebraically to determine the overall pressure drop.

Lockhart Martinelli – Lockhart Martinelli correlations models
the two phase pressure drop in terms of a single phase
pressure drop multiplied by a correction factor. Acceleration
changes are not included.

Beggs and Brill (No Acc.) – The Beggs and Brill methods
without the acceleration term.

Beggs and Brill (Homog.) – The Beggs and Brill methods with
a homogeneous acceleration term.

Dukler (AGA Head) - Uses the AGA equation for the
calculation of the static head term rather than the Eaton
equation which can be poor when you have small quantities of
liquid in the system.

Horizontal/Inclined method (as defined on the Calculation
Options Editor) will be used.
35
Input Field
Description
Vertical
Pipes
The Vertical method applies only when you have selected Two-Phase
pressure drop. The options are:
Elements
36

Isothermal Gas - This is a compressible gas method that
assumes isothermal expansion of the gas as it passes along
the pipe. Aspen Flare System Analyzer uses averaged
properties of the fluid over the length of the pipe. The outlet
temperature from the pipe is calculated by adiabatic heat
balance either with or without heat transfer. Pressure losses
due to change in elevation are ignored.

Adiabatic Gas - This is a compressible gas method that
assumes adiabatic expansion of the gas as it passes along the
pipe. As with the Isothermal Gas method, pressure losses due
to changes in elevation are ignored.

Beggs & Brill - Although the Beggs and Brill method was not
originally intended for use with vertical pipes, it is
nevertheless commonly used for this purpose, and is
therefore included as an option for vertical pressure drop
methods. For more details, see Chapter 9 Theoretical Basis.

Dukler - Although the Dukler method is not generally
applicable to vertical pipes, it is included here to allow
comparison with the other methods.

Orkiszewski - This is a pressure drop correlation for vertical,
two-phase flow for four different flow regimes - bubble, slug,
annular-slug transition and annular mist. For more details,
see Appendix A - Theoretical Basis.

Lockhart Martinelli – Lockhart Martinelli correlations models
the two phase pressure drop in terms of a single phase
pressure drop multiplied by a correction factor. Acceleration
changes are not included.

Beggs and Brill (No Acc.) – The Beggs and Brill methods
without the acceleration term.

Beggs and Brill (Homog.) – The Beggs and Brill methods with
a homogeneous acceleration term.

Vertical method (as defined on the Calculation Options
Editor) will be used.
For two-phase calculations, the pipe segment is divided into a
specified number of elements. On each element, energy and material
balances are solved along with the pressure drop correlation. In
simulations involving high heat transfer rates, many increments may
be necessary, due to the non-linearity of the temperature profile.
Obviously, as the number of increments increases, so does the
calculation time; therefore, you should try to select a number of
increments that reflects the required accuracy.
4 Pipe Network
Input Field
Description
Friction
Factor
Method
The Friction Factor Method applies only when you have entered a
value for friction factor. The options are:
Static Head
Contribution

Round - This method has been maintained primarily for
historical purposes in order for older Aspen Flare System
Analyzer calculations to be matched. It tends to over predict
the friction factor by up to 10% in the fully turbulent region.

Chen - It should always be the method of preference since it
gives better predictions at the fully turbulent flow conditions
normally found within flare systems.

Friction Factor Method (as defined on the Calculation
Options Editor) will be used.
The following options are available:

Include - The static head contribution to total pressure drop in
the pipe segments is included.

Ignore Downhill Recovery - The static head recovery term is
ignored for downhill sections of pipe.

Ignore - The static head contribution to the pressure drop
calculation for all pipe segments is ignored.
Include is applied by default.
Solver Group
Damping
Factor
The damping factor used in the iterative solution procedure. If this is
left blank, the value in the Calculation Options Editor is used.
Note: When you are sizing a flare system, the initial pipe diameters may
affect the solution when there is a liquid phase and the liquid knockout drum
is modeled. You should initially size a network using vapor phase methods.
Summary Tab
The results of the calculation are displayed.
4 Pipe Network
37
Fig 4.8
Multiple Editing
You can edit multiple pipe segments simultaneousl
simultaneously
y by highlighting them in
the Pipe Manager with the mouse cursor while keeping the Shift
S
key
pressed. After you have finished selecting pipe segments, click Edit to open
the common Pipe Editor
Editor.
The common pipe editor view differs from that of the single p
pipe
ipe editor view
in the following respects:
38

Only fields that can be edited in multiple mode are displayed.

The input fields have an additional entry, *. This entry indicates
that the value should remain at the pre edit value.

In the following figure of the Dimensions tab; we enter * for the
Length and Elevation Change fields to indicate that these must
not be changed. We specify new values for the Roughness and
the Thermal Conductivity
Conductivity. We select * for the Use Class and
Sizeable boxes to indicate that these must be changed.
4 Pipe Network
Fig 4.9
Pipe Class Editor
The Pipe Class Editor allows you to edit the allowable schedules for each
nominal diameter, for both Carbon Steel and Stainless Steel,
Steel during sizing
calculations.
s. It also allows you to restrict the range of pipe sizes that may be
selected during design calculations.
To access the Pipe Class Editor
Editor, click Pipe Class in Tools,, on the Home
tab.
4 Pipe Network
39
Fig 4.10
Note: If you have selected Use Pipe Class in the Preference Editor, these
are the schedules which will be used.
40
4 Pipe Network
5 Nodes

Overview

Node Manager

Ignoring/Restoring Nodes

Connection Nodes

Boundary Nodes
Overview
Pipes are connected via nodes, which can be added, edited and deleted from
the Node Manager. Sources are also added through the Node Manager.
Node Manager
To access the Node Manager:
Click Nodes in Build, on the Home tab.
5 Nodes
41
Fig 5.1
Button
Description
Add
You will be prompted to select the type of node. This new node will be
named with a number depending upon the number of nodes of that
type already added.
Edit
Allows you to edit the currently highlighted node. The form varies,
depending on the type of node, as discussed below.
Delete
Allows you to remove the currently highlighted node.
Close
Closes the Node Manager.
Ignoring/Restoring Nodes
When you ignore a single node, all upstream nodes are automatically ignored.
You can ignore sin
single
gle or multiple nodes within the model. When you ignore a
single node, all upstream nodes are automatically ignored. This enables you
to do what if type calculations, where part of the network can be excluded
from the calculation without the need for delet
deletion
ion and reinstallation of the
appropriate nodes.
To ignore a node
node:
42
1
Open the node editor of the node that you want to ignore.
2
On the Connections tab, select the Ignore check box. The following
fo
figure shows this for a connector node
node.
5 Nodes
Fig 5.2
To restore a node that has previously been ignored:
1
Open the node editor of the node that you want to restore.
2
On the Connections tab, clear the Ignore check box.
Connection Nodes
The following types of connection nodes are available in Aspen Flare System
Analyzer. A connection node is one that links two or more pipe segments.

Connector

Flow Bleed

Horizontal Separator

Orifice Plate

Tee

Vertical Separator
Connector
The Connector is used to model the connection of two pipes. The diameters
of the pipes may be different.
5 Nodes
43
Connections Tab
The name of the connector and connectivity information is specified here.
Fig 5.3
The location can have an alphanumeric name. This feature is useful for large
flowsheets, because you can provide a different “location” name to different
sections to make it more comprehensible.
Field
Description
Name
The alphanumeric description of the Connector (e.g. - HP Connect
1).
Location
You may want to specify the location of the node in the plant.
Upstream/
Downstream
Either type in the name of the pipe segment or select from the list.
At
You can specify the end of the pipe segment attached to the
connector.
Ignore
Select the Ignore check box to ignore this connector in the
calculations. Clear the check box to re-enable it.
Calculations Tab
Calculation methods are spec
specified here.
44
5 Nodes
Fig 5.4
Field
Description
Angle
Specify the connector expansion angle. If not defined, it will be
calculated from Length.
Length
Enter the connector length. If not defined, it will be calculated
calcula
from
Angle
Angle.
Fitting Loss
Method
The available options are:
Isothermal
Pressure Drop

Equal Static Pressure – Pressure drop calculation is ignored
and static pressure is balanced.

Calculated – Pressure drop is calculated in accordance with
the Swage method.
If this option is set to Yes,, the inlet temperatures used for the size
change calculations in the connector will not update during iterative
calculations for pressure loss i.e. a PT flash will be used to update
the inlet properties. If the option is set to No, a more rigorous PH
flash will be used to update the inlet properties.
The connector will do one size change calculation between the inlet
and outlet diameters selecting expansion or contraction as
appropriate.
Setting this option to Yes can speed
ed up calculations in some cases
at cost of a minor loss of accuracy.
Two Phase
Correction
5 Nodes
If this option is set to Yes, the pressure loss coefficient in two phase
flow will be calculated using properties corrected for liquid slip. If set
to No, the homogenous
enous properties of the fluid will be used in
calculating the pressure loss coefficient.
45
Field
Description
Swage
Method

Compressible - pressure losses will be calculated assuming
compressible flow through the connector at all times.

Incompressible (Crane) - pressure losses will be calculated
assuming incompressible flow through the connector at all
times. Loss coefficients are calculated using Crane
coefficients.

Transition - pressure losses will be calculated initially using
the assumption of incompressible flow. If the pressure loss
expressed as a percentage of the inlet pressure is greater
than the defined compressible transition value then the
pressure drop will be recalculated using the compressible
flow method.

Incompressible (HTFS) - pressure losses will be calculated
times. Loss coefficients are calculated using HTFS
correlations
The Incompressible method calculations are faster but will be
less accurate at higher pressure drops. The Transition method
can cause instabilities in some cases if the calculated pressure
drop is close to the transition value.

Compressible
Transition
Balance Total Pressure – Frictional pressure drop is ignored
and total pressure is balanced between upstream &
downstream.
This entry defines the pressure drop as a percentage of the inlet
pressure at which compressible flow pressure drop calculations
should be used. It applies only when the Transition method is
selected.
Summary Tab
The result of the calculations at each of the pipe connections is displayed.
46
5 Nodes
Fig 5.5
Flow Bleed
The Flow Bleed is a simple calculation block that allows you to;

Specify a fixed pressure drop
drop.

Specify a constrained flow offtake wh
where
ere the flow offtake is calculated
from the following equation
equation:
Offtake = Multiplier x Inlet Flow + Offset
The calculated Offtake is constrained to maximum and minimum values.
Connections Tab
The name of the flow bleed and connectivity information is specified
speci
here.
5 Nodes
47
Fig 5.6
Field
Description
Name
The alphanumeric description of the Flow Bleed (e.g. - HP Connect
XX).
Location
Upstream/
Downstream
At
You can specify the end of the pipe segment attached to the flow
b
bleed.
Ignore
Select the Ignore check box to ignore this flow bleed in the
Calculations Tab
48
5 Nodes
Fig 5.7
Field
Description
Offtake Multiplier
Specify the Offtake multiplier. The default value is 0.
Offtake Offset
Specify the Offset
et for the Offtake to compensate for the changes
in the inlet flow.
Offtake Minimum
Specify the minimum value for the Offtake.
Offtake
Maximum
Specify the maximum value for the Offtake.
Pressure Drop
Enter the pressure drop across the Flow Bleed.
Summary
ry Tab
5 Nodes
49
Fig 5.8
Horizontal Separator
Horizontal separators
eparators are used to allow liquid to separate from the feed
stream
m so that it can be removed from the flare system. The liquid phase in
the horizontal separator
eparator feed is removed from the network. In Aspen Flare
System Analyzer, the Horizontal Separator has one primary inlet, one
secondary inlet/outlet, and one vapor outl
outlet stream.
Connections Tab
The name of the horizontal separator and connectivity information is specified
here.
50
5 Nodes
Fig 5.9
You only need to provide 2 of 3 connections to be able to solve the separator.
This allows for solution(s) to partially built network
networks.
Field
Description
Name
The alphanumeric description of the Horizontal Separator
(e.g. - HP KO Drum).
Location
The location can have an alphanumeric
hanumeric name. This feature is
useful for large flowsheets, because you can provide a different
“location” name to different sections to make it more
comprehensible.
(Primary
/Secondary)
Inlet/Outlet
Either type in the name of the pipe segment or select from the
list.
At
You can specify the end of the pipe segment attached to the
horizontal separator.
Ignore
Select the Ignore check box to ignore this horizontal separator
in the calculations. Clear the check box to re-enable
enable it.
Calculations Tab
Calculation
tion methods are specified here.
5 Nodes
51
Fig 5.10
Field
Description
Dimensions Group
Diameter
The internal diameter of the vessel.
Liquid Level
The liquid level in the vessel. Pressure drop is calculated based
upon the vapor space above the liquid.
Methods Group
Fitting Loss
Method
52
The available options are;


Calculated_Ignore Vena Contracta – Pressure drop is
calculated in accordance with the Swage method but
ignores the loss due vena contracta.

the Swage method including the loss due vena contracta.
5 Nodes
Field
Description
Isothermal
Pressure Drop
If this option is set to Yes, the inlet temperatures used for the size
change calculations in the separator will not update during
iterative calculations for pressure loss i.e. a PT flash will be used to
update the inlet properties. If the option is set to No, a more
rigorous PH flash will be used to update the inlet properties.
The horizontal separator does three size change calculations, one
between each stream connection and the vessel body. Normally
these will be expansion calculations for the primary and secondary
inlets and a contraction calculation for the vapor outlet but they
will automatically change if flows are reversed.
Setting this option to Yes can speed up calculations in some cases
Size Change Group
Two Phase
Correction
If this option is set to Yes, the pressure loss coefficient in two
phase flow will be calculated using properties corrected for liquid
slip. If set to No, the homogenous properties of the fluid will be
used in calculating the pressure loss coefficient.
Method

Compressible - Pressure losses will be calculated assuming

Incompressible (Crane) - Pressure losses will be calculated
coefficients.

Transition - Pressure losses will be calculated initially using
flow method.

Incompressible (HTFS) - Pressure losses will be calculated
correlations

Compressible
Transition
5 Nodes
downstream.
selected.
53
Field
Description
Body
Dimension
If this option is set to Full Body Area, the calculation for the
primary inlet/vessel and secondary inlet/vessel size change will
wi
use the whole vessel area. If Partial Body Area on Flow is
selected, the vessel area is reduced in proportion to the
appropriate flow, i.e. if the secondary inlet volumetric flow is 20%
of the total volumetric flow in the tee then 20% of the body area
will
ill be used in the size change calculation. The use of the Partial
Body Area on Flow option has the effect of increasing the
pressure loss calculated by simple fixed K factors.
Composition Tab
If the inlet feed flashes in the separator and as a result of the flash, the
mixture is converted into liquid fully and the vapor outlet will have no flow.
This can cause instability in the pressure solution of the whole network. To
avoid this, Aspen Flare System Analyzer creates an arbitrary vapor phase with
very small
all vapor fraction for the vapor outlet (<0.001%). You can specify the
composition of the vapor phase here.
Fig 5.11
54
5 Nodes
Design Tab
Fig 5.12
Field
Description
Min Drop Diameter
Enter the diameter of the minimum drop size to be
removed.
Drain Volume
Enter the drain volume.
Maximum Holdup time
Enter maximum holdup time before the horizontal
separator will be drained.
Design Length
Minimum length
ength of the horizontal separator required to
satisfy design conditions.
Settling Velocity
Settling velocity of the minimum drop size to be removed.
Summary Tab
5 Nodes
55
Fig 5.13
Orifice Plate
An Orifice Plate is a thin plate, which has a clean-cut hole
ole with straight walls
perpendicular to the flat upstream face of the plate placed crossways in the
pipe. Orifice plates are generally used to restrict the flow downstream of a
blow down valve or restrict the flow from a high pressure section of a flare
system
ystem to a low pressure section. They may also be used to allow flow
measurement.
Connections Tab
The name of the orifice plate and connectivity information is specified here.
56
5 Nodes
Fig 5.14
Field
Description
Name
The alphanumeric description of the Orifice Plate (e.g. HP OP).
Location
You may want to specify the location of the node in the
plant.
Upstream/Downstream
Either type in the name of the pipe segment or select from
the list.
At
You can specify the
e end of the pipe segment attached to
the orifice plate.
Ignore
Select the Ignore check box to ignore this orifice plate in
the calculations. Clear the check box to re--enable it.
Calculations Tab
5 Nodes
57
Fig 5.15
Note: You
ou only need to provide 1 of 3 sizing parameters. For Example, if you
entered the Diameter
Diameter, Aspen Flare System Analyzer will then calculate the
Upstream Diameter Ratio and the Downstream Diameter Ratio.
Ratio
Field
Description
Dimensions Group
Diameter
The diameter of the orifice hole.
Upstream
Diameter Ratio
The ratio of the throat diameter to the upstream pipe diameter.
Downstream
Diameter Ratio
The
he ratio of the throat diameter to the downstream pipe diameter.
diameter
Methods Group
Fitting Loss
Method
58

Ignored - If this option is selected, the fitting losses for the
orifice plate would not be calculated. Static pressure is
balanced.

Thin Orifice - The fitting losses for the orifice
ice plate will be
calculated using the equations for the thin orifice plate.

Contraction/Expansion - For this method, orifice plates will be
modeled as a sudden contraction from the inlet line size to
the diameter of the hole followed by a sudden expansion from
the diameter of the hole to the outlet line size.
5 Nodes
Field
Description
Isothermal
Pressure
Drop
change calculations in the orifice plate will not update during iterative
calculations for pressure loss i.e. a PT flash will be used to update the
inlet properties. If the option is set to No, a more rigorous PH flash
will be used to update the inlet properties.
The orifice plate will do one contraction calculation and one expansion
calculation if the Fitting Loss Method is set to
Contraction/Expansion. Setting this option to Yes can speed up
calculations in some cases at cost of a minor loss of accuracy.
Size Change Group
Two Phase
Correction
to No, the homogeneous properties of the fluid will be used in
Method


coefficients.

pressure drop will be recalculated using the compressible flow
method.

correlations.
The Incompressible method calculations are faster but will be less
accurate at higher pressure drops. The Transition method can cause
instabilities in some cases if the calculated pressure drop is close to
the transition value.

Compressible
Transition
5 Nodes
downstream.
selected.
59
Summary Tab
Fig 5.16
Tee
The Tee is used to model the connection of three pipes
pipes.. The diameters of the
pipes may be different.
Connections Tab
The name of the tee and connectivity information is specified here.
60
5 Nodes
Fig 5.17
You only need to provide 2 of 3 connections to be able to solve the tee. This
allows for solution(s) to partially built networks.
Field
Description
Name
The alphanumeric description of the Tee (e.g. - HP
Tee 1).
Location
You may want to specify the location of the node in
the plant. The location can have an alphanumeric
alphanumer
name. This feature is useful for large flowsheets,
because you can provide a different “location” name
to different sections to make it more comprehensible.
Upstream/Downstream/Branch
Either type in the name of the pipe segment or select
from the list.
At
You can specify the end of the pipe segment attached
with the tee.
Ignore
Select the Ignore check box to ignore this tee in the
calculations. Clear the check box to re-enable
re
it.
Calculations Tab
5 Nodes
61
Fig 5.18
The
e following fields are available on this tab:
Field
Description
Dimensions Group
Theta
Specify the angle of the branch to the upstream connection of the
tee.
Body
Specify the diameter of the body of the tee. Allowable choices are:

Run - The diameter will
ill be that of the inlet pipe.

Tail - The
he diameter will be that of the outlet pipe.

Branch - The
he diameter will be that of the branch pipe.

Auto - Set the body diameter to be larger of the inlet and
branch pipe diameters.
Methods Group
62
5 Nodes
Field
Description
Fitting Loss
Method
Miller Chart
Extrapolation
Connector If
Incomplete


Simple - This method uses a constant, flow ration
independent K factor for the loss through the branch and
run.

Miller - This method uses a K factor which is interpolated
using Miller Curves, which are functions of the flow and area
ratios of the branch to the total flow as well as the branch
angle. Loss coefficients at low values of the branch are to
body area are extrapolated from the data presented on the
charts.

Miller (Area Ratio Limited) – This method uses a K factor
which is interpolated using Miller Curves, which are
functions of the flow and area ratios of the branch to the
total flow as well as the branch angle. The ratio of the
branch area to body area is constrained by the lower limit
presented on the charts.


Gardel – This method calculates the K factor using the
analytical equations of Gardel.

None – No extrapolation is used. If the data falls outside the
Miller chart, a fixed value of K (K=8.0) is used.

Miller Area Ratio Squared – Uses a K factor which is
extrapolated using Miller Curves, assuming that the K
factors are functions of the flow and area ratio squared, of
the branch to the total flow as well as the branch angle.

Gardel – Uses the Gardel method to calculate K factor if the
K factor is out of bounds in miller chart.
If this option is set to Yes, Aspen Flare System Analyzer will treat
the Tee as a straight connector, ignoring the effect of the branch on
pressure drop.
The Tee will do three size change calculations between inlet/body,
branch/body and body/outlet selecting expansion or contraction
calculations as appropriate.
Isothermal
Pressure Drop
change calculations in the tee will not update during iterative
calculations for pressure loss, i.e. a PT flash will be used to update
the inlet properties. If the option is set to No, a more rigorous PH
Swage Method Group
Two Phase
Correction
5 Nodes
to No, the homogenous properties of the fluid will be used in
63
Field
Description
Method

compressible flow through the tee at all times.

assuming incompressible flow through the tee at all times.
Loss coefficients are calculated using Crane coefficients.

flow method.

assuming incompressible flow through the tee at all times.
Loss coefficients are calculated using HTFS correlations.
accurate at higher pressure drops. The Transition method can
cause instabilities in some cases if the calculated pressure drop is
close to the transition value.

downstream.
Compressible
Transition
selected.
Body
Dimension
If this option is set to Full Body Area, the calculation for the
inlet/body and branch/body size change will use the whole body
area. If Partial Body Area on Flow is selected, the body area is
reduced in proportion to the appropriate flow, i.e. if the branch
volumetric flow is 20% of the total volumetric flow in the tee then
20% of the body area will be used in the size change calculation.
This option is ignored if the fittings loss method is set to Miller. The
use of the Partial Body Area on Flow option has the effect of
increasing the pressure loss calculated by simple fixed K factors
bringing the results closer to those calculated by the ore accurate
Miller K factors.
Summary Tab
64
5 Nodes
Fig 5.19
Vertical Separator
Vertical separators
eparators are used to allow liquid to separate from the feed stream
so that it can be removed from the flare system. The liquid phase in the
vertical separator
eparator feed is removed from the network. In Aspen Flare System
Analyzer, the Vertical Separator has only one inlet and one vapor outlet
stream.
Connections Tab
The name of the vertical separator and connectivity information is specified
here.
5 Nodes
65
Fig 5.20
Field
Description
Name
The alphanumeric description of the Vertical Separator (e.g. - HP KO
Drum).
Location
Inlet/Outlet
At
You can specify the end of the pipe segment attached to the vertical
separato
eparator.
Ignore
Select the Ignore check box to ignore this vertical separator in the
Calculations Tab
66
5 Nodes
Fig 5.21
Field
D
Description
Diameter
The internal diameter of the vessel.
Methods Group
Fitting Loss
Method
Isothermal
Pressure Drop


Calculated Ignore Vena Contracta – Pressure
sure drop is
calculated in accordance with the Swage method but
ignores the loss due vena contracta.

the Swage method including the loss due vena contracta.
If this optio
option is set to Yes,, the inlet temperatures used for the size
change calculations in the separator will not update during iterative
calculations for pressure loss i.e. a PT flash will be used to update
the inlet properties. If the option is set to No, a more rigorous
r
PH
The vertical separator will do one expansion calculation for the inlet
stream entering the vessel and one contraction calculation for the
flow from the vessel to the outlet. These will automatically
automatic
change if
flows through the vessel are reversed.
Size Change Group
5 Nodes
67
Field
Description
Two Phase
Correction
to No, the homogenous properties of the fluid will be used in
Method


coefficients.

flow method.

correlations.

Compressible
Transition
downstream.
selected.
Composition Tab
If the inlet feed flashes in the separator, as a result of the flash, the mixture
is converted into liquid fully and the vapor outlet will have no flow. This can
cause instability in the pressure solution of the whole network. To avoid this,
Aspen Flare System Analyzer creates an arbitrary vapor phase with very small
vapor fraction for the vapor outlet (<0.001%). You can specify the
composition of the vapor phase here.
68
5 Nodes
Fig 5.22
5 Nodes
69
Design Tab
Fig 5.23
Field
Description
Min Drop Diameter
Enter the diameter of the minimum drop size to be
removed.
Design Diameter
Minimum diameter of the vertical separator required to
satisfy design conditions.
Settling Velocity
Settling velocity
elocity of the minimum drop size to be removed.
Summary Tab
70
5 Nodes
Fig 5.24
Boundary Nodes
The following types of boundary nodes are available in Aspen Flare System
Analyzer. A bounda
boundary
ry node is one that is connected to only one pipe segment.

Control Valve

Relief Valve

Flare Tip
The relief valve and control valve node types represent sources or inflows into
the system. The Control Valve,, in particular, may also be used to model
alternative
ive types of sources
sources, such as blow down valves, rupture disks, and
purge valves.
Control Valve
The Control Valve is used to model a constant flow source, such as purge
valves, bursting
ting disks and blow down valves. The most significant difference
to the Relief Valve is that the rated flow equals the nominal flow.
Connections Tab
The name of the control valve and connectivity information is specified here.
5 Nodes
71
Fig 5.25
The location can h
have
ave an alphanumeric name. This feature is useful for large
Field
Description
Name
The al
alphanumeric description of the Control Valve (e.g. - FCV 1).
Location
Outlet
At
You can specify where the pipe segment is to be attached to the control
valve.
alve.
Ignore
Select the Ignore check box to ignore this control valve in the
Conditions Tab
Fluid conditions are specified here.
72
5 Nodes
Fig 5.26
It is recommended that a value for Outlet Temperature which corresponds
to an isenthalpic flash from the upstream conditions down to the Allowable
Back Pressure.. This will give the highest probable entry temperature into
the system which will in turn give the highest velocities.
The following
lowing fields are available on this tab:
Field
Description
Conditions Group
5 Nodes
Inlet Pressure
The pressure of the source on the upstream side of the valve.
Inlet Temp.
Spec.
The temperature specification of the source on the upstream
ups
side
of the control valve. You can select the fluid condition from the list
on the left side. The available options are:

Actual - The given inlet temperature is the actual fluid
temperature.

Superheat - If this option is selected, enter the amount of
superheat.

Subcool - If this
s option is selected, enter the amount of
subcooling.
73
Field
Description
Allowable Back
Pressure
The Allowed Back Pressure is the pressure that is allowed to
exist at the outlet of a pressure relief device as a result of the
pressure in the discharge system. It is the sum of the
superimposed and built-up back pressure. Clicking Set calculates
the Allowable Back Pressure as a function of the Inlet
Pressure. Selecting the Auto check box will automatically
calculate the Allowable Back Pressure whenever the Inlet
Pressure changes.
Outlet
Temperature
This is the temperature of the source at the flange on the
downstream side of the valve.
If the enthalpy method chosen is the Ideal Gas model, this
temperature is used to determine the enthalpy of the source at the
entrance to the pipe network; otherwise, this enthalpy is calculated
from the upstream pressure and temperature. If Set was clicked,
and the enthalpy model is Peng Robinson, Soave Redlich
Kwong or Lee Kesler, the outlet temperature will be calculated
from the upstream temperature and pressure after isenthalpic
expansion to the defined Allowable Back Pressure.
Mass Flow
This is the mass flow of the source. This is generally the flow rate
generated by the upset condition.
Dimensions Group
Flange
Diameter
This is the diameter of the flange at the valve discharge. The flange
diameter may be left unknown in which case it will be assumed to be
the same as the outlet pipe.
Composition Tab
The fluid composition is specified here.
74
5 Nodes
Fig 5.27
Field
Description
Basis
T
The composition basis, which may be either Molecular
ecular Weight,
Mole Fraction or Mass Fraction.
Mol. Wt.
The molecular weight of the fluid. You can only enter data here if
the composition basis selected is molecular weight..
If the composition basis selected is Mole Fraction or Mass
Fraction
Fraction,, the molecular weight is updated when you enter or
change the component fractions.
Fluid Type
If molecular weight is selected , you need to select the Fluid Type
to calculate a binary composition in order to match the molecular
weight. If the two components of the specified fluid type are not
found
found, the other components are used.
Component
Fractions
The fluid composition in either mole or mass fractions. You can only
enter data here if the composition basis selected is mole or mass
fractions. You can normalize the composition either manually editing
the component fractions or by clicking Normalise.
If the composition Basis selected is molecular weight, the
component fractions are estima
estimated
ted when you change the molecular
weight.
5 Nodes
75
Field
Description
Clone
Composition
From
This button allows the copying of compositional data from another
control valve in the same scenario.
Normalise
Normalises the composition such that the sum of the component
fractions is 1.
Methods Tab
Fig 5.28
Fields
76
Description
5 Nodes
Fields
Description
VLE Method
The options for the Vapor-Liquid Equilibrium calculations are as
follows (see Chapter 9 Theoretical Basis):

Compressible Gas – Real Gas relationship. This is only

Peng Robinson – Peng Robinson Equation of State. This is
only available when the Enthalpy Method on the

Soave Redlich Kwong – Soave Redlich Kwong Equation of
State. This is only available when the Enthalpy Method on
the Calculation Options Editor is NOT Ideal Gas.

Vapour Pressure – Vapour Pressure method as described in
API Technical Data Book– Volume 113. This is only available
when the Enthalpy Method on the Calculation Options
Editor is NOT Ideal Gas.

Model Default - If this is selected, the Default method for
the VLE method (as defined on the Calculation Options
Swage Group
Fitting Loss
Method
Isothermal
Pressure Drop


the Swage method.
change calculations in the control valve will not update during
The control valve will do one size change calculation from the
defined flange diameter to the outlet pipe diameter. This will
normally be an expansion.
Two Phase
Correction
5 Nodes
to No, the homogeneous properties of the fluid will be used in
77
Fields
Description
Method


coefficients.

flow method.

correlations.

Compressible
Transition
downstream.
selected.
Estimated Properties at Header Conditions Group
Vapour
Fraction
The initial estimates for the flow profile in looped systems are
generated based on the assumption of vapor phase flow without any
liquid knockout in the system. It is not uncommon for sources to
pass through a knockout drum before connection to the main
header. Specification of an estimate of vapor fraction of the fluid at
the knockout drum can considerably enhance the automatically
generated flow profile. If not specified, for the initial estimates, the
fluid is assumed to be vapor only at the header condition.
Vapour Mol.
Wt.
Specify the estimated vapor molecular weight for the vapor fraction
given above. If provided, this value is used to assist the automatic
generation of the flow profile for looped systems. If not specified, for
the initial estimates, the vapour molecular weight is assumed to be
the same as the overall fluid molecular weight at the header
condition.
Inlet Piping Tab
Details of the piping between the protected equipment and the inlet to the
control valve are specified here. This data is used to calculate the pressure
drop in the inlet piping. The diameter of the inlet piping is also used to
calculate the inlet velocity of the source fluid when the Include Kinetic
Energy option is selected in the Calculation Options Editor.
78
5 Nodes
Fig 5.29
The available fields are:
Fields
Description
Routing Group
Length
The length of the inlet piping.
Elevation
Change
The change in elevation of the inlet piping. Th
This
is cannot be greater
than the length of the piping.
Properties Group
Material
The material of the inlet pipe
pipe, either Carbon Steel or Stainless
Steel
Steel.
Roughness
The surface roughness of the inlet pipe. Whenever a material is
selected, the absolute roughn
roughness
ess is initialized to the default value for
the material as defined on the Preferences Editor.
Diameter Group
5 Nodes
Nominal
Diameter
The nominal pipe diameter used to describe the inlet pipe size. For
pipes with a nominal diameter of 14 inches or more, this will
wi be the
same as the outside diameter of the pipe.
Schedule
If a pipe schedule is selected, you will be able to select a nominal pipe
diameter from the pipe databases. It will not be necessary to specify
the internal diameter.
79
Fields
Description
Internal
Diameter
Use Pipe
Class
Select Yes to restrict the sizes of the inlet piping selected to those
defined by the Pipe Class tool.
Fittings Groups
Loss
Coefficient
Enter the A and B parameters for the following fitt
fittings
ings K factor
equation in which Ft is the friction factor for fully developed turbulent
flow:
K = A + BFt
Summary Tab
The result of the calculations is displayed.
Fig 5.30
80
5 Nodes
Relief
ief Valve
The Relief Valve source can be used to model types of spring loaded relief
valves. Relief valves are used frequently in many industries in order to
prevent dangerous situations occurring from pressure build
build-ups
ups in a system.
Connections Tab
The name
ame of the relief valve and connectivity information is specified here.
Fig 5.31
5 Nodes
81
Field
Description
Name
The alphanumeric description of the Relief Valve (e.g. - FCV 1).
Location
Outlet
At
You can specify where the pipe segment is to be attached to the relief
valve.
Ignore
Select the Ignore check box to ignore this relief valve in the
Conditions Tab
Fluid conditions are specified here.
82
5 Nodes
Fig 5.32
It is recommended that a value for Outlet Temperature which corresponds
to an isenthalpic flash from the upstream conditions down to the Allowable
Back Pressure.. This will give the highest probable entry temperature into
the system which will in turn give the highest velocities.
Field
Description
Conditions Group
MAWP
5 Nodes
The Maximum Allowable Working Pressure (MAWP
MAWP) is the
maximum gauge pressure
e permissible in a vessel at its operating
temperature. It is normally equal to the relief valve set pressure
unless you have a low pressure vessel.
83
Field
Description
Contingency
In general there are two types of process upset conditions:
Relieving
Pressure

Operating - The relieving pressure is 110% of MAWP
unless you have a multiple valve assembly in which case it
is 116% of MAWP. Some of the operating upset examples
are cooling failure, power failure and instrument air failure.

Fire - The relieving pressure is 121% of MAWP.
The Relieving Pressure is equal to the valve set pressure plus the
overpressure. You can either enter the value or have it calculated
using the MAWP and the Contingency by clicking Set. If you
entered a value less than the MAWP, a warning message will be
generated.
Selection of the Auto check box will automatically calculated the
relieving pressure from the MAWP and Contingency whenever
these values change.
Inlet Temp.
Spec.
Allowable Back
Pressure
The temperature specification of the source on the upstream side of
the relief valve. You can select the fluid condition from the drop
down box on the right hand side of this field. The available options
are:

Actual - It uses the given inlet temperature as the actual
fluid temperature.

Superheat - If this option is selected, enter the amount of
superheat.

Subcool - If this option is selected, enter the amount of
subcooling.
The Allowable Back Pressure is the pressure that is allowed to
exist at the outlet of a pressure relief device as a result of the
pressure in the discharge system. It is the sum of the
superimposed and built-up back pressure. Clicking Set calculates
the Allowable Back Pressure as a function of the valve type and
MAWP.
If the Auto check box is selected then the allowed back pressure is
automatically updated whenever the valve type or MAWP is
changed.
Outlet
Temperature
This is the temperature of the source on the downstream side of
the valve.
If the enthalpy method chosen is the Ideal Gas model, then this
temperature is used to determine the enthalpy of the source at the
entrance to the pipe network, otherwise this enthalpy is calculated
by isenthalpic flash from the upstream pressure and temperature.
If Set is pressed and the enthalpy model is Peng Robinson,
Soave Redlich Kwong or Lee Kesler, the outlet temperature will
be calculated from the upstream temperature and pressure after
expansion to the defined Allowable Back Pressure.
Mass Flow
The nominal mass flow of the source. This is generally the flowrate
generated by the upset condition.
Rated Flow
It is the rated mass flow of the source. This is generally the
flowrate that the relief valve is capable of passing.
Clicking Set calculates the rated flow from the MAWP, valve type,
orifice area, valve count, upstream pressure, upstream temperature
and sizing method. If the Auto check box is selected, the rated
flow will be automatically updated after any change in these values.
Rated Flow Parameters
84
5 Nodes
Field
Description
K(Cp/Cp-R)
K is the Ideal Gas ratio of specific heats.
Compressibility
Compressibility Factor for the deviation of the actual gas from a
perfect gas evaluated at inlet conditions. (Z= PV/MRT)
Valve Design Group
Flange
Diameter
The diameter of the valve discharge flange. The flange diameter
may be left unknown in which case it will be assumed to be the
same as the outlet pipe.
Number of
Valves
Specify the number of valves for the source.
Orifice Area
Per Valve
The orifice area per valve may be set by selecting the orifice size
code from the list. The corresponding orifice area will then be
displayed. If the size code is set to the blank entry, the orifice area
per valve may be entered manually.
Valve Type
The choices are:
Mech. BP Limit

Balanced - A spring loaded pressure relief valve that
incorporates a means for minimizing the effect of back
pressure on the performance characteristics.

Conventional - A spring loaded pressure relief valve whose
performance characteristics are directly affected by changes
in the back pressure on the valve.

Pilot - A pilot-operated pressure relief valve in which the
pilot is a self-actuated device. The major relieving device is
combined with and is controlled by the pilot.
The maximum mechanical back pressure that can be applied to the
valve.
Composition Tab
The fluid composition is specified here.
5 Nodes
85
Fig 5.33
The
e following fields are available on this tab:
Field
Description
Basis
The composition basis, which may be either Molecular
ecular Weight, Mole
Fraction or Mass Fraction.
Mol. Wt.
The
he molecular weight of the fluid. You can only enter data here if the
compositi
composition basis selected is Molecular Weight.
If the composition basis selected is Mole Fraction or Mass Fraction,
the molecular weight is updated when you enter or change the
component fractions.
Fluid Type
86
If Molecular Weight is selected in the composition basis
bas list, you need to
select the Fluid Type to calculate a binary composition in order to
match the molecular weight. If the two components of the specified fluid
type are not found
found, the other components are used.
5 Nodes
Field
Description
Component
Fractions
The fluid composition in either mole or mass fractions. You can only
enter data here if the composition basis selected is mole or mass
Fraction. You can normalize the composition by either manually editing
the component fractions or by clicking Normalise.
If the composition basis selected is Molecular Weight, the component
fractions are estimated when you change the molecular weight.
Clone
Composition
From
This button allows the copying of compositional data from another relief
valve in the same scenario.
Normalise
Normalises the composition such that the sum of the component
fractions is 1.
Methods Tab
5 Nodes
87
Fig 5.34
Field
88
Description
5 Nodes
Field
Description
VLE Method
The options for the Vapor-Liquid Equilibrium calculations are as
follows (see Chapter 9 Theoretical Basis):

Compressible Gas – Real Gas relationship. This is only

Peng Robinson – Peng Robinson Equation of State. This is
only available when the Enthalpy Method on the

Soave Redlich Kwong – Soave Redlich Kwong Equation of
State. This is only available when the Enthalpy Method
on the Calculation Options Editor is NOT Ideal Gas.

Vapour Pressure – Vapour Pressure method as described in
API Technical Data Book– Volume 113. This is only
Options Editor is NOT Ideal Gas.

Model Default - If this is selected, the Default method for
the VLE method (as defined on the Calculation Options
Swage Group
Fitting Loss
Method
Isothermal
Pressure Drop


the Swage method.
change calculations in the relief valve will not update during
The relief valve will do one size change calculation from the
defined flange diameter to the outlet pipe diameter. This will
normally be an expansion. Setting this option to Yes can speed up
calculations in some cases at cost of a minor loss of accuracy.
Two Phase
Correction
5 Nodes
If this option is set to Yes, the pressure loss coefficient in two
phase flow will be calculated using properties corrected for liquid
slip. If set to No, the homogeneous properties of the fluid will be
used in calculating the pressure loss coefficient.
89
Field
Description
Method


coefficients.

flow method.

correlations.

Compressible
Transition
downstream.
selected.
Sizing Method Group
Sizing Method
90
The four sizing method options available are:

API (1976) – American Petroleum Institute method in the
1976 edition of RP 520 pt 1. No account is made of liquid
flashing as it passes through the relief valve, thus this
method is not recommended for either two phase or
flashing fluids.

API (1993) – American Petroleum Institute method in the
1993 edition of RP 520 pt 1. Liquid flashing is handled by a
simplified approach in which the fluid is flashed to the
outlet pressure. The relative quantities of each phase at
the outlet condition are then used at the inlet of the valve
to determine the two phase capacity

API(2000) – American Petroleum Institute method in the
2000 edition of RP 520 pt 1. This method is often referred
to as the Diers or Leung method. This is the
recommended method for all two phase fluids.

HEM – Homogeneous Equilibrium method.
Back Pressure
Back pressure to be used for rating the relief valve. If this value is
not specified, the Allowable Back Pressure is used.
MultiPhase Cd
Discharge coefficient to be used of relief valve in multiphase
service.
Liquid Cd
Discharge coefficient to be used for relief valves in liquid service.
5 Nodes
Field
Description
Kb
User defined back pressure correction factor. If this field is left
blank, the back pressure correction factor is calculated. This value
should only be specified in exceptional cases.
Energy Balance Group
Isentropic Flash
Select Yes to use an isentropic flash between the inlet and outlet
otherwise an isenthalpic flash will be done.
Isentropic
Efficiency
Fractional isentropic efficiency for the isentropic flash.
Estimated Properties at Header Conditions Group
Vapour Fraction
The initial estimates for the flow profile in looped systems are
generated based on the assumption of vapor phase flow without
any liquid knockout in the system. It is not uncommon for sources
to pass through a knockout drum before connection to the main
header. Specification of an estimate of vapor fraction of the fluid at
the knockout drum can considerably enhance the automatically
generated flow profile. If provided, this value is used to assist the
automatic generation of the flow profile for looped systems. If not
specified, for the initial estimates, the fluid is assumed to be
vapour only at the header condition.
Vapour Mol.
Wt.
Specify the estimated vapor molecular weight for the vapor
fraction given above. If provided, this value is used to assist the
automatic generation of the flow profile for looped systems. If not
specified, for the initial estimates, the vapour molecular weight is
assumed to be the same as the overall fluid molecular weight at
the header condition.
Inlet Piping Tab
Details of the piping between the protected equipment and the inlet to the
relief valve are specified here. This data is used to calculate the pressure drop
in the inlet piping to ensure that it does not exceed the recommended limit of
3% of the inlet pressure. The diameter of the inlet piping is also used to
calculate the inlet velocity of the source fluid when the Include Kinetic
Energy option is selected in the Calculation Options Editor.
5 Nodes
91
Fig 5.35
The available fields are:
Field
Description
Routing Group
Length
The length of the inlet piping.
Elevation
Change
The change in elevation of the inlet piping. T
This
his cannot be greater
than the Length of the piping.
Properties Group
Material
The material of the inlet pipe
pipe, either Carbon Steel or Stainless
Steel
Steel.
Roughness
The surface roughness of the inlet pipe. Whenever a material is
selected, the absolute roughness is initialized to the default value for
the material as defined on the Preferences Editor.
Diameter Group
92
5 Nodes
Field
Description
Nominal
Diameter
The nominal pipe diameter used to describe the inlet pipe size. For
pipes with a nominal diameter of 14 inches or more, this will be the
same as the outside diameter of the pipe.
Schedule
If a pipe schedule is selected, you will be able to select a nominal pipe
diameter from the pipe databases. It will not be necessary to specify
the internal diameter.
Internal
Diameter
Use Pipe
Class
Select Yes to restrict the sizes of the inlet piping selected to those
defined by the Pipe Class tool.
Fittings Groups
Loss
Coefficient
Enter the A and B parameters for the following fittings K factor
equation in which Ft is the friction factor for fully developed turbulent
flow:
K = A + BFt
Summary Tab
The result of the calculations is displayed.
5 Nodes
93
Fig 5.36
Source Tools
The initial sizing of a flare system is time consuming both in terms of time
taken to build the model and the computation time. Using an Ideal Gas
method can speed up the calculation during the initial sizing estimation.
Speed is an important issue during sizing calculations especially for a complex
multiple scenario case. Typically, the back pressure should be used for
calculations. Rigorous rating calculation for all scenarios can be done by the
Peng Robinson enthalpy method or any other enthalpy methods with
pressure dependency and provides the downstream temperature.
94
5 Nodes
Updating Downstream Temperatures
The downstream temperatures are only used to define the system entry
temperature when ideal gas enthalpies are used. After several cycles of rating
and sizing calculations, the original values for each source may no longer be
valid. These values may be updated to reflect the results of the last
calculation using an equation of state enthalpy method as follows:
Click Source Tools in Tools on the Home tab; select Refresh Source
Temperatures from the list.
Adding Single Source Scenarios
The thorough evaluation of a flare network will require the evaluation of many
scenarios. In most systems, there will be the possibility of each relief valve
lifting on its own. In the case of a petrochemical complex, this could have
several hundred relief valves and the task of setting up the scenarios for each
relief valve would be time consuming and error prone.
Once all the major scenarios have been defined, select Add Single Source
Scenarios from Source Tools. Click Yes to allow Aspen Flare System
Analyzer to analyze the existing scenarios to determine the greatest flow rate
for each relief valve and create a scenario using this data.
Flare Tip
The Flare Tip is used to model outflows from the system. It can model either
ignited combustible gas flare tips or open vents. Nonphysical equipment such
as a connection to a fixed pressure exit at a plant boundary can also be
modeled.
Connections Tab
The name of the flare tip and connectivity information is specified here.
5 Nodes
95
Fig 5.37
The location
n can have an alphanumeric name. This feature is useful for large
Field
Description
Name
The alphanumeric description of the Flare Tip (e.g. - HP Flare
Tip).
Location
Upstream node
Either type in the name of the pipe segment or select from list.
At
You can specify the end of the
e pipe segment attached to the flare
tip.
Ignore
Select the Ignore check box to ignore this flare tip in the
Calculations Tab
96
5 Nodes
Fig 5.38
The following fields are a
available on this tab:
Field
Description
Diameter
You can specify a diameter for the tip. If this value is not
specified then the diameter of the connected pipe is used.
Methods Group
Use Curves
Select this check box if you are supplying pressure drop curves
c
to
calculate the pressure drop of the flare tip. Data for these curves
is entered on the Curves tab.
Fitting Loss
Coefficient
The fitting loss coefficient will be used to calculate the pressure
drop through the flare tip.
Fittings Loss
Coefficient Basis
Select whether the supplied Fittings Loss Coefficient will
calculate the total pressure loss including velocity
locity pressure loss
or static pressure loss only.
Isothermal
Pressure Drop
If this option is set to Yes,, the inlet temperatures used for the
size
ze change calculations in the flare tip will not update during
iterative calculations for pressure loss i.e. a PT flash will be used
to update the inlet properties. If the option is set to No, a more
prope
The flare tip will do a one size calculation for the change in
diameter between inlet pipe and the flare tip.
Setting this option to Yes can speed up calculations in some
cases at cost of a minor loss of accuracy.
5 Nodes
97
Curves Tab
User specified pressur
pressure
e drop curves are specified here. These will only be
used if the Use Curves field on the Calculation tab
ab is unchecked.
Fig 5.39
98
Field
Description
Ref. Temp.
Enter the reference temperature to which the pressure
pr
drop
curves correspond. All curves must be for the same reference
temperature.
Pressure
Correction
If checked, the static pressure correction takes into account
density differences due to both the calculated inlet pressure and
calculated inlet pressure.
sure. The temperature correction is
automatically applied, but this box must be checked in order for
pressure effects to be modeled. This box should normally be
checked.
Mol. Wt.
Extrapolation
If this is selected, extrapolation beyond the range of supplied
supplie
molecular weight curves is performed if necessary; otherwise,
the bounding molecular weight curve is used.
Flow
Extrapolation
If this is selected, extrapolation beyond the range of supplied
mass flow rates is performed if necessary; otherwise, the
bounding mass flow is used.
5 Nodes
Field
Description
Mol. Wt.
Enter the molecular weight at which the pressure drop curve
applies. Add Mol. Wt. can be used to add additional curves. The
list can then be used to select which pressure drop curve is
displayed. Delete Mol. Wt. will delete the selected pressure drop
curve.
Mass Flow/Pres.
Drop
These pairs of data define points in the pressure drop curve.
Points may be added and removed from the curve by using Add
Point and Delete Point.. Pressure drops for flows between those
in the table are
re calculated using linear interpolation.
Summary Tab
The result of the calculation is displayed.
Fig 5.40
5 Nodes
99
100
5 Nodes
6 Calculations

Starting the Calculations

Efficient Modeling Techniques
Starting the Ca
Calculations
The following words before the object on the status bar show the type of
calculation being performed
performed:

B = Mass and Energy Calculations

P = Pressure Drop Calculations
To start the calculations, select Run from the Run group, on the Home tab of
the Ribbon.
The status of the rating calculations is shown on the Status Bar.
Bar The icon on
the left corner of the Status Bar shows the status of the current case. The
second display fiel
field
d on the Status Bar shows firstly the inner properties loop
iteration number, then the maximum pressure error for that iteration and
finally the name of the pipe segment responsible for the error. The third
display field shows firstly the number of iterati
iterations
ons taken by the loop solver,
and then the error in the objective function being solved by the loop solver.
The right corner of the Status Bar shows the Zoom Slider.. You can slide to
the percentage zoom setting to quickly zoom in or zoom out when viewing the
t
Process Flowsheet.
Fig 6.1
To abort calculations
calculations, click Stop, which activates during calculations.
Note: Due to speed considerations, it is recommended that sizing calculations
be performed subject to the constraints: Compressible Gas VLE,
VLE Ideal Gas
Enthalpy Method,, or no Heat Transfer Calculations.
6 Calculations
101
Efficient Modeling Techniques
Efficient modeling of a flare network requires some forethought in order to
meet the primary objectives which are in general:
1
Definition of the design constraints for the flare system. These are usually
defined by company standards or by local health and safety regulations. If
unavailable, standard texts such as API-RP-521 can be used to select
preliminary acceptable values.
2
Efficient acquisition of the data for the piping configuration and layout.
3
Definition of the scenarios or contingencies which should be evaluated.
Grass roots design will require analysis of a far wider range of scenarios to
those required by the simple expansion of a flare system to incorporate a
new relief valve.
4
Rapid construction of the computer model of the flare system.
5
Fast and efficient calculation of the computer model of the flare system.
Objectives 1 to 3 can only be achieved by the use of engineering skill and
judgment. Once complete, the efficient use of Aspen Flare System Analyzer
can lead to a satisfactory project conclusion.
Data Entry
Aspen Flare System Analyzer has a wide range of methods for entering the
data for each object within the model. In general, you should use the method
that you are most comfortable with, but experience has shown that use of the
Process Flowsheet environment for definition of the piping configuration and
layout can save many man days of labor with large flare networks.
Although there is no set order in which the model must be built, the
recommended sequence of data entry for building the model is:
102
1
Define the project description, user name, etc. by selecting Description
from the Application Menu which is displayed after clicking the aspenONE
Button on the upper left corner of the application window.
2
Set preferences for the default piping materials, type of Tee, composition
basis, etc. from the Preferences Editor, accessed via the Application
Menu. These may be overwritten on an object by object basis at any
stage. Ensure that the Edit Objects On Add check box is selected if you
want to edit the object data as each new flowsheet object is created.
3
Define a pipe class if appropriate. This will ensure that you only use pipe
sizes as allowed by your project. Open the Pipe Class Editor in the Tools
group on the Home tab of the Ribbon.
4
With the Calculation Options Editor, define default calculation methods
for VLE, Pressure Drop, etc. To open this view, click Options in the Run
group on the Home tab.
5
Define all the source nodes (relief valves and control valves) for the first
scenario. The first scenario should be the one that has the greatest level
of common data amongst the complete set of scenarios. The
recommended method of creation is to drag the nodes from the Palette
to the Process Flowsheet.
6 Calculations
6
Define the design constraints on Mach number, noise, etc. for the first
scenario using the Scenario Manager. To access this dialog box, in the
Build group on the Home tab, click Scenarios.
7
Define the pipe network (common to all scenarios). If the network is to be
sized, some care must be taken in defining reasonable estimates for the
pipe diameters.
8
Add the next scenario by clicking Add on the Scenario Manager. The
data for the sources should be cloned from the previously defined scenario
that has the most similar data. Edit the design constraints of this scenario
if necessary.
9
Make the new scenario current. Highlight it on the Scenario Manager
and click Current.
10 Edit the source data for each source for the new scenario. Double-click
sources on the Process Flowsheet.
11 Repeat steps 8 through 10 for all scenarios.
Calculation Speed
Calculation time will often be only a small percentage of the time taken to
construct the computer model. However, on low specification personal
computers, a sizing calculation for a complex multiple scenario model could
take several hours, if not days, when care is not taken in the selection of the
thermodynamic models or in the definition of the component slate.
When considering the desired accuracy for the calculations, due consideration
must be given to the fact that you are modeling a system that will rarely
come close to a steady state condition, with a steady state modeling tool.
Component Slate
As a rule of thumb you can assume that the calculation time is proportional to
the square of the number of components. This is especially true when the
VLE is calculated by an equation of state instead of treating the fluids as a
simple compressible gas.
Flare systems generally operate at conditions in which heavy components
such as hexane or heavier will stay in the liquid phase throughout the system.
You should therefore endeavor to characterize the heavy ends of petroleum
fluids by as few components as possible. The properties that you use for the
characterization should be optimized to:

Ensure the component stays in the liquid phase.

Match the liquid phase density.
VLE Method
Source compositions may be modeled either by definition of a molecular
weight or by a detailed component by component analysis. When a
composition is defined solely by molecular weight, Aspen Flare System
Analyzer analyzes the user defined component slate to select a pair of
components whose molecular weights straddle the defined value. A binary
composition is then calculated to match this value. This type of fluid
characterization is only suitable for network analyses in which the fluids are
6 Calculations
103
assumed to be vapor, since the VLE behavior cannot be reasonably predicted
from this level of detail. Thus the Compressible Gas VLE method is the only
one that should ever be used in association with molecular weight modeling.
When modeling using a detailed component by component analysis, if you are
confident that the system will be liquid free, then the Compressible Gas VLE
method should be used since it does not have the overhead of determining
the vapor/liquid equilibrium split. The computation time for the fluid
properties then becomes several orders of magnitudes faster that those
involving a liquid phase.
When modeling a system in which two phase effects are important,
consideration must be given to the pressures both upstream of the sources
and within the flare piping. The Vapor Pressure VLE method, which is the
fastest of the multiphase methods, is, strictly speaking, only valid for
pressures below 10 bar. The reduced temperature of the fluid should also be
greater than 0.3. Experience has shown that it also works to an acceptable
degree of accuracy for flare system analysis at pressures well beyond this. If
speed is an issue, it is recommended that a scenario with as many active
sources as possible be rated both using one of the cubic equations of state
and this method. If acceptable agreement between the results is achieved, it
may be reasonably assumed that the extrapolation is valid.
Sizing Calculations
The final calculations upon which a flare system is built should of course be
made using the most detailed model consistent with the quality of data
available, but for initial sizing calculations, a number of points should be
considered when selecting appropriate calculation methods.

There is not generally a great deal of difference between the pressure
drops calculated for a two phase system, whether calculated by
treating the system as a compressible gas or as a two phase fluid. This
occurs since the fluid condenses the velocities will decrease while the
two-phase friction factor will increase.

Unless choked flow is allowed in the system, the back pressure on
each source should not vary greatly with line size. The specification of
a reasonable fixed downstream temperature for each source to be
used with the ideal gas enthalpy model should therefore give
reasonable results.
The recommended procedure for performing sizing calculations is as follows:
1
Build the network using reasonable estimates for the pipe diameters.
Estimate the diameters from:
d
W
300PM
d = Diameter (m)
W = Mass flow (kg/s)
P = Tip pressure (bar abs)
M = Design mach number
104
6 Calculations
6 Calculations
2
Rate the network for all the scenarios with your desired detailed model for
the VLE and enthalpies. This will give reasonable temperatures
downstream of each source.
3
Copy the calculated temperatures downstream of each source to the
source data by selecting Refresh Source Temperatures from Source
Tools in the Tools group on the Home tab of the Ribbon.
4
Size the network for all scenarios using Compress Gas VLE and Ideal
Gas enthalpies.
5
Rate the network for all the scenarios with your desired detailed model for
the VLE and enthalpies. If there are any design violations, make a
debottlenecking calculation with these methods.
105
106
6 Calculations
7 Databases

Overview

Database Features

Setting the Password

Pipe Schedule Database Editor

Fittings Database Editor

Component Database Editor
Overview
The data for the various installable components of the model are stored in
user-modifiable database files.
The database files are:

PIPE_SCHEDULE.MDB - The pipe schedule database. This contains
data for both carbon steel and stainless steel pipe.

FITTINGS.MDB - The pipe fittings database.

COMPONENTS.MDB - The pure component database.
These files are initially installed to the Database sub-directory in your Aspen
Flare System Analyzer working directory.
Note: You may add and edit your own data to the databases. However, you
cannot edit or delete any of the original data.
The databases may be password protected by a single password common to
each. If the password has been disabled, or an incorrect access password has
been entered, the databases may be reviewed in read-only mode. You must
have defined an access password before any database can be edited.
Note: Original data is always read-only.
7 Databases
107
Database Features
The Navigation Pane and tabbed environment provide a new user friendly way
to navigate and view simultaneously multiple results and input views. Input
and Results open in a tabbed environment like Microsoft Internet Explorer. All
the windows are dockable allowing you to organize and customize the
workspace.
Grid Controls
The data view is supported with rich grid controls for all input and result
views. The grid controls permit you to sort, custom filter on every column
field. With filtering, you can restrict the data and choose to view only those
that want to see.
To access the filters in the data grid, click the filter icon
header to display a list in which you can choose from.
in the column
You may use the following pre-defined auto filters:

Blanks

NonBlanks

Above Average

Below Average

Top 10

Top 10 percentile

Bottom 10

Bottom 10 percentile
If you need to add a custom filter, select Custom from the list. The Custom
Filter Selection window is displayed.
You need to add and edit the Operator and Operand in the table, then
group them with logical conjunction and disjunction to setup a custom filter.
Button
Description
Add Condition
Add a condition in the table. You need to choose a proper Operator,
and then input a value for the Operand to complete the new
condition.
Remove
Condition (s)
Remove one or more previously added conditions. Press Ctrl to select
multiple rows in the table.
Group Selected
108
'And' Group
Group the selected conditions and perform the logical AND operation
for the group. Multiple conditions need to be selected before this
button is activated.
'Or' Group
Group the selected conditions and perform the logical OR operation
for the group. Multiple conditions need to be selected before this
button is activated.
Toggle
Toggle the selected logical groups between the logical operations
AND and OR.
7 Databases
Button
Description
Ungroup
Upgroup the selected conditions.
A logical formula is displayed under the table to show the relation for all the
conditions added. Click OK to apply the custom filter.
Maneuvering Through the Table
Click the table to select a record, and then navigate through the table using
the navigator and scroll bar controls.
Fig 7.1
Printing
Click Print All to print the pipe schedule, fittings or component data,
depending on which editor you are currently using. Aspen Flare System
Analyzer prints format
formatted
ted output using the default printer settings.
Adding/Deleting Data
When Add is clicked, a new record that contains dummy data is inserted as
the last record on the table. You should override this data with your actual
data.
1. When you add items, they will then become immediately available to the
simulation.
2. Click Delete to delete the current record.
7 Databases
109
Note: You can only delete your own data.
3. Click OK to confirm the update for database.
Setting The Password
To set or modify the password:
Select Set Password from the Application Menu that can be opened by
clicking the aspenONE button on the upper left corner of the application
window.
The Password
ord Editor window will now be displayed.
Fig 7.2
If you have already set your password, you first need to enter the existing
password before supplying the new one.
1. Enter your existing password in the Old Password box.
2. Enter your new password in both the New Password and Confirm New
Password boxes, and then click OK. Click Cancel to abort the procedure.
Pipe Schedule Database Editor
The Pipe Schedule Database Editor allows you to view the pipe schedule
data for all pipes
s in the database, and to add and edit user
user-defined
defined entries.
1
110
To use the Pipe Schedule Database Editor
Editor, select Pipe Schedule
Database Editor from the Databases tab on
n the Navigation Pane.
Pane After
you enter the password, tthe Pipe Schedule Database Editor view will
be displayed.
7 Databases
Fig 7.3
2
If you have already set your password, you will need to enter the
password before accessing the databases.
3
Select the mat
material you want to view from the Material list. This may be
either Carbon Steel or Stainless Steel.
The Nominal Diameter
Diameter, Schedule, Internal Diameter, Wall Thickness
and Group for each entry are tabulated.
The database can be modified by either adding or de
deleting
leting the entries using
Add or Delete,, respectively. Click Print All to print the database to the
printer defined in the Page Setup dialog box that can is opened from File |
Page Setup in the Print Preview window.
For information on the Database view fea
features
tures that are common to the Pipe
Schedule, Fittings and Components Databases, see Database Features.
Features
7 Databases
111
Fittings Database Editor
The Fittings Database Editor allows you to view the pipe fittings
fitt
data for all
fittings types in the database, and to add and edit user
user-defined
defined entries.
To display the Fittings Database Editor
Editor, select Fittings Database Editor
from the Database
Databases tab on the Navigation Pane.. After you enter the
password, the Fittings D
Database Editor will be displayed.
Fig 7.4
The description of each fitting, as well as the A and B term in the pipe fitting
equation is tabulated. The Reference defines the literature source for the
data.
The pipe fitting equation is:
K  A  BFt
For information on the Database view features that are common to the Pipe
Schedule, Fittings and Components Databases, see Database Features.
Features
Component Database Editor
The Component Dat
Database Editor allows you to view the component data
for all the pure components in the database, and to add and edit user-defined
user
entries.
112
7 Databases
To display the Component Database Editor
Editor, select Components
Component
Database Editor from the Database tab on the Navigation Pane.
Pa
After you
enter the password, the Component Database Editor will be displayed.
Fig 7.5
The data for each component in the database is tabulated.
For information on the Database view features that are common to the Pipe
Schedule, Fittings and Componen
Components Databases, see Database Features.
Features
Importing Component Data
Additional components may be added to the database via an ASCII file whose
format is given in Appendix A – File Format.
7 Databases
113
114
7 Databases
8 Automation

Overview

Objects

Aspen Flare System Analyzer Object Reference

Example

Updating Automation Files From Previous Versions
Overview
Automation, defined in its simplest terms, is the ability to drive one
application from another. For example, the developers of Product A have
decided in their design phase that it would make their product more usable if
they exposed Product A’s objects, thereby making it accessible to automation.
Since Products B, C and D all have the ability to connect to the application
that have exposed objects, each can programmatically interact with product
A.
The exposure of its objects makes Aspen Flare System Analyzer a very
powerful and useful tool in the design of hybrid solutions. Since access to an
application through Automation is language-independent, anyone who can
write code in Visual Basic, C++ or Java, to name three languages, can write
applications that will interact with Aspen Flare System Analyzer. There are a
number of applications that can be used to access Aspen Flare System
Analyzer through Automation, including Microsoft Visual Basic, Microsoft Excel
and Visio. With so many combinations of applications that can transfer
information, the possibilities are numerous and the potential for innovative
solutions is endless.
8 Automation
115
Objects
The key to understanding Automation lies in the concept of objects. An object
is a container that holds a set of related functions and variables. In
Automation terminology, the functions of an object are called Methods and
the variables are called Properties. Consider the example of a simple car. If
it were an object, a car would have a set of properties such as; make, color,
engine, etc. The car object might also have methods such as; drive, refuel,
etc. By utilizing the properties and methods of the car object it is possible to
define, manipulate and interact with the object.
Fig 8.1
Each property of the car is a variable that has a value associated with it. The
color could be either a string or a hexadecimal number associated with a
specific color. The gas mileage could be a floating-point value. Methods are
nothing more than the functions and subroutines associated with the object.
An object is a container that holds all the attributes associated with it. An
object can contain other objects that are a logical subset of the main object.
The car object might contain other objects such as engine or tire. These
objects have their own set of independent properties and methods. An engine
can have properties related to the number of valves and the size of the
pistons. The tires would have properties such as the tread type or model
number.
Object Hierarchy
The path that is followed to get to a specific property may involve several
objects. The path and structure of objects is referred to as the object
hierarchy. In Visual Basic the properties and methods of an object are
accessed by hooking together the appropriate objects through a dot operator
(.) function. Each dot operator in the object hierarchy is a function call. In
many cases it is beneficial to reduce the number of calls by setting
intermediate object variables.
For instance, expanding on our previous example involving the car, suppose
there exists an object called Car and you wish to set the value of its engine
size. You could approach the problem in one of two ways.
Direct specification of object property
Car.Engine.Size = 3
Indirect specification of object property
116
8 Automation
Dim Eng1 as Object
Set Eng1 - Car.Engine.Size
Eng1 = 3
If the Engine size is a property that you wish to access quite often in your
code, using the indirect method of specification might be easier as it reduces
the amount of code thereby reducing the possibility of error.
The Aspen Flare System Analyzer Type
Library
In order to do anything with objects it is first necessary to know what objects
are available. When an application is exposed to Automation, a separate file is
usually created that lists all the objects and their respective properties and
methods. This file is called the type library and nearly all programs that
support Automation have one of these files available. With the help of an
Object Browser, such as the one built into Microsoft Excel, you now have a
way to view all the objects, properties, and methods in the application by
examining the type library. For Aspen Flare System Analyzer, the type library
is contained within the file AspenTech.FlareSystemAnalyzer.Interfaces.dll.
The Aspen Flare System Analyzer type library reveals numerous objects that
contain many combine properties and methods. The type library shows the
associated properties and methods for every object, and returns type for
every property. The type library shows what types of arguments are required
and what type of value might be returned for every method.
Accessing a specific property or method is accomplished in a hierarchical
fashion by following a chain of exposed objects. The first object in the chain is
an object from which all other objects can be accessed. This object will
typically be the main application. In Aspen Flare System Analyzer, the
starting object is the Application object. All other objects are accessible from
this starting object.
Object Browser
The type library itself does not exist in a form that is immediately viewable to
you. In order to view the type library, you require the use of an application
commonly referred to as an Object Browser. The Object Browser will
interpret the type library and display the relevant information. Microsoft Excel
and Visual Basic both include a built in Object Browser.
Accessing the Object Browser in Excel for V7.3
Onwards
8 Automation
1
Press <Left Alt><F11> or select Visual Basic Editor from Macro group
in the Tools menu (For Excel 2007 or later, please select Visual Basic in
the Code group on the Developer tab).
2
Within the Visual Basic Editor, choose References from the Tools menu.
3
Select the box next to AspenTech.FlareSystemAnalyzer.Interfaces. If
this is not displayed, use Browse to locate
AspenTech.FlareSystemAnalyzer.Interfaces.dll.
117
4
Click OK.
5
Choose Object Browser from the View menu or press <F2>.
6
Click the arrow in the box at the upper left of the window, and then select
s
AspenTech.FlareSystemAnalyzer
FlareSystemAnalyzer.Interfaces.dll from the list.
Example: Navigating through the type library
This example shows how to navigate through tthe
he type library in order to
determine the object hierarchy necessary to access a particular property. The
desired property is the mass flow of a relief valve called “PSV 1” in the
currently active scenario.
The first step is to start with the starting obje
object
ct that in the case of Aspen
Flare System Analyzer is always the Application object.
Fig 8.2
Selecting the Application object in the browser reveals all of its related
properties and methods. Examination of the list of properties does not reveal
a relief valve object so access to a particular relief valve must be through
another object. The properties that are links to other objects can be
determined by looking at the type shown when a property is selected. If the
type is not String
String, Boolean, Variant, Double, Integer or Long then it is
most likely an object. The object type shown will be found somewhere in the
object list and the next step is to determine the object hierarchy.
With prior experience in Aspen Flare System Analyzer, the ReliefValves
object is a logical choice.
118
8 Automation
Fig 8.3
The ReliefValves object is shown to be of type IReliefValve.. This object is a
simple object that is a collection of other objects with some properties and
methods for navigation through the collection.
Fig 8.4
The Item proper
property
ty is shown to return an indexed object of type
IReliefValve,, The argument named “What” is of type Variant which is the
default argument type for an argument unless otherwise specified. All
collection objects within Aspen Flare System Analyzer allow access to an
individual member of the collection either by index number (like an array) or
8 Automation
119
directly by name. Named arguments are case insensitive so “PSV 1” is the
same as “psv 1”. Either approach is equally valid.
Examining the IReliefValve object type shows a property called
PropertyByName
PropertyByName, which is type Variant.
Fig 8.5
This property is a read/write property that is used to access all data for a
relief valve.
The argument is a case insensitive string that describes the variable that we
wish to access. In th
this
is case this string would have the valve “MassFlow”. A full
list of property names for each type of object is given at the end of this
chapter.
The resulting syntax to access the desired property is:
ReliefValves.Item(“PSV1”).PropertyByName(“MassFlow”)
Automation
omation Syntax
Declaring Objects
An object in Visual Basic is another type of variable and should be declared.
Objects can be declared using the generic type identifier object.
object The
preferred method however uses the type library reference to declare the
object
ect variables by an explicit object name.
Early Binding:
Dim | Public | Private Objectvar as ObjectName as specified in the type
library
Late Binding:
120
8 Automation
Dim | Public | Private objectvar as Object
Once a reference to a type library has been established, the actual name of
the object as it appears in the type library can be used. This is called early
binding. It offers some advantages over late binding, including speed and
access to Microsoft’s IntelliSense functionality when using Visual Basic or
VBA.
Example: Object Declaration
Early Binding:
Public fnApp as Object
Public thisPsv as Object
Late Binding:
Public fnApp as AspenTech.FlareSystemAnalyzer.Interfaces.Application
Public thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve
The Set Keyword
Syntax:
Set objectvar = object.[object...].object | Nothing
Connections or references to object variables are made by using the Set
keyword.
Example: Set
Assuming fnApp is set to the Application Object
Dim thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve
Set thisPsv - fnApp.ReliefValves.item(1)
CreateObject, GetObject
Syntax for creating an instance of an application:
CreateObject (class)
GetObject ([pathname] [,class])
Where class is the starting object as specified in the type library.
In order to begin communication between the client and server applications,
an initial link to the server application must be established. In Aspen Flare
System Analyzer this is accomplished through the starting object
Application.
The CreateObject function will start a new instance of the main application.
CreateObject is used in Aspen Flare System Analyzer with the
AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In
terfaces.Application class as defined in the type library. This connects to the
main application interface of Aspen Flare System Analyzer.
8 Automation
121
Example: CreateObject
Dim FnApp As Object
Set FnApp = CreateObject
(“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.
Interfaces.Application”)
The following example uses early binding in the object declaration to create
an instance of Aspen Flare System Analyzer and then load a specified model.
Example: CreateObject
Dim FnApp As
terfaces.Application
FnApp.OpenModel “c:\Aspen Flare System Analyzer
<version>\Samples\Ole\Excel\olesample.fnw”
The GetObject function will connect to an instance of the server application
that is already running. If an instance of the application is not already running
then a new instance will be started.
Object Properties, Methods and Hierarchy
Syntax for creating and accessing properties:
Set objectvar = object.[object.object...] .object
Variable = object.[object.object...] .object.property
Syntax for accessing methods:
Function Method
returnvalue = object.method ([argument1, argument2, ...])
Subroutine method
object.method argument1, argument2, ...
The sequence of objects is set through a special dot function. Properties and
methods for an object are also accesses through the dot function. It is
preferable to keep the sequences of objects to a minimum since each dot
function is a call to a link between the client and the server application.
The object hierarchy is an important and fundamental concept for utilizing
automation. A particular property can only be accessed by following a specific
chain of objects. The chain always begins with the Application object and
ends with the object containing the desired property.
The methods of objects are accessed in the same fashion as properties by
utilizing the dot function. A method for a particular object is nothing more
than a function or subroutine whose behavior is related to the object in some
fashion.
122
8 Automation
Typically the methods of an object will require arguments to be passed when
the method is called. The type library will provide information about which
arguments are necessary to call a particular method. A function will return a
value.
Note: Subroutines in Visual Basic do not require parentheses around the
argument list.
Examples: Accessing Aspen Flare System
Analyzer Object Properties
Dim FnApp As
Dim SepDiam as Double
SepDiam - FnApp.HorizontalSeparators.Item[1].PropertyByName
(“Diameter”)
This example starts up Aspen Flare System Analyzer and opens a specific
case. The diameter of a specific horizontal separator is then obtained. The
diameter is obtained through a connection of the Application and
HorizontalSeparators objects.
Dim FnApp As
Dim Seps as
terfaces.IHorizontalSeparators
Dim Sep as
terfaces.IHorizontalSeparator
Dim SepDiam as Double
Set Seps = FnApp.HorizontalSeparators
Set Sep = Seps.Item[I]
SepDiam = Sep.PropertyByName (“Diameter”)
8 Automation
123
This example also gets the diameter of a specific horizontal separator, but
creates all the intermediate objects so that when the diameter value is
actually requested the chain of objects only contains one object.
Collection Objects
Syntax: Properties of a Collection Object:

Item(Index) -- Accesses a particular member of the collection by name
or number

Count -- Returns the number of objects in the collection
Syntax: Enumeration of Objects:
Dim Element as Object
Dim iElement as Long
Dim nElements as Long
For iElement=1 to nElements
Set Element = FnApp.Elements.Item(iElement)
[statements]
Next [element]
A collection object is an object that contains a set of other objects. This is
similar to an array of objects. The difference between an array of objects and
a collection object is that a collection object is that a collection object contains
a set of properties and methods for manipulating the objects in the collection.
The Count property returns the number of items in the collection and the
Item property takes an index value or name as the argument and returns a
reference to the object within the collection.
Examples: Accessing Collection Objects
Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValves
Dim name as String
Dim i As Integer
Set myPsvs = myApp.ReliefValves
For i = 1 To myPsvs.Count
name = myPsvs.Item(i).PropertyByName(“Name”)
MsgBox name
Next i
This example connects to a collection of relief valves by setting the myPsvs
object. A For loop is created that uses the Count and item properties of a
collection in order to display a message box that display the name of each
relief valve in turn. The items in the collection are indexed beginning at 1. The
application object is assumed to have been already set to myApp.
Variants
Syntax: Using variant values:
124
8 Automation
Dim myvariant as Variant
myvariant = [object.property]
To determine the upper and lower bound of the variant:
UBound(arrayname[,dimension])
LBound(arrayname[,dimension])
A property can return a variety of variable type. Values such as
Temperature or Pressure are returned as Doubles or 32-bit floating point
values. The Name property returns a String value. Visual Basic provides an
additional variable called Variant. A Variant is a variable that can take on
the form of any type of variable including Integer, Long, Double, String,
Array, and Objects.
If the property of an object returns an array whose size can vary depending
upon the case, then a Variant is used to access that value. For example, the
Composition property of a ControlValve returns an array of Doubles sized
to the number of components in the model.
In Visual Basic, if a variable is not explicitly declared then it is implicitly a
Variant. Variants have considerably more storage associated with their use
so for a large application it is good practice to limit the number of Variants
being used. It is also just good programming practice to explicitly declare
variables whenever possible.
Example: Using Variants in Aspen Flare System
Analyzer
Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve
Dim molefracs as Variant
Dim i As Integer
Set myPsv = myApp.ReliefValves.Item(1)
molefracs = myPsv.PropertyByName (“Composition”)
For i = LBound(molefracs) To Ubound (molefracs)
Debug.Print molefracs(i)
Next i
This example shows how to get the mole fractions of a relief valve for the
current scenario. The values are sent to the Visual Basic Immediate window.
The application object is assumed to have been already set to myApp.
Unknown Values
There are a number of occasions where a variable may be unknown such as
all the calculated values prior to the calculation or the flange size of a control
valve. In all cases this is represented by the value
fntVariableStatus_fntUnknownValue.
8 Automation
125
Example: Using Unknown Values in Aspen Flare
System Analyzer
Dim myValve as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValves
Dim myValves as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValve
Dim flange as Double
Dim name as String
Set myValves = myApp.ControlValves
For i=1 to myValves.Count
flange = myValves.Item(i).PropertyByName (“FlangeDiameter”)
If flange = fntVariableStatus_fntUnknownValue Then
name = myValve.PropertyByName(“Name”)
MsgBox name
EndIf
Next i
This example loops through all the control valves and displays the name of
any whose flange diameter is unknown. The application object is assumed to
have been already set to myApp.
Object Reference
The following subsections summarize the methods and properties available for
each object available within Aspen Flare System Analyzer. They are ordered
purely alphabetically.
For each object the attributes comprise the type (or class) of object followed
by the access characteristics which may be read-only or read/write. In
general, data has the read/write attribute and calculated values have the
read-only attribute.
Each method is shown with the method name including any arguments, a
description of the method and a description of the arguments.
Each property is shown with the property name including any arguments, a
description of the property, the property attributes and a description of the
arguments. Optional arguments are shown in square brackets [].
Many objects support a PropertyByName property. In such cases a further
table gives the valid property names which are case insensitive as well as the
property attributes and the units of measure where appropriate. The property
names will generally match the field descriptions on the corresponding views
but they never contain any space characters.
126
8 Automation
Application
Description : Application object
Methods
Name
Description
Arguments
OpenModel(fileName As
String)
Open an Aspen Flare
System Analyzer model
fileName = Model filename
SaveModel(fileName As
String)
Save an Aspen Flare
System Analyzer model
DoImport(imType As
Import an Aspen Flare
importType, source As
System Analyzer Model
String, Definition As
String, Flag As Reserved)
As Integer
imType = 0,1,2 for
xml,xls,mdb files
DoExport(exType As
Export an Aspen Flare
exportType, source As
System Analyzer Model
String, Definition As
String, Flag As Reserved)
As Integer
exType = 0,1,2 for xml, xls,
mdb files
LaunchFlarenet([fileName Display the Aspen Flare
As String])
System Analyzer
application window
Quit()
Please call this method before
your scripts end.
source = Import filename
Definition = Definition filename
Flag = 0
source = Export filename
Definition = Definition filename
Flag = 0
Quit Aspen Flare System
Analyzer.
Note: The LaunchFlarenet method only launches the Aspen Flare System
Analyzer Graphical User Interface (GUI) in a separate process which cannot
be controlled directly. The Quit method cannot terminate the GUI opened by
the LaunchFlarenet method.
Properties
8 Automation
Name
Description
Attributes
Bleeds
Collection of flow bleed
objects
IBleeds, readonly
Components
Collection of component
objects
IComponents,
read-only
Connectors
Collection of connector
objects
IConnectors,
read-only
ControlValves
Collection of control valve
objects
IControlValves,
read-only
HorizontalSeparat
ors
Collection of horizontal
separator objects
IHorizontalSepar
ators,
read-only
Nodes
Collection of node objects
INodes, readonly
OrificePlates
Collection of orifice plate
objects
IOrificePlates,
read-only
Pipes
Collection of pipe objects
IPipes, read-only
ReliefValves
Collection of relief valve
objects
IReliefValves,
read-only
Arguments
127
Name
Description
Attributes
Scenarios
Collection of scenario objects
IScenarios, readonly
Solver
Solver object
ISolver, readonly
Tees
Collection of tee objects
ITees, read-only
Tips
Collection of flare tip objects
ITips, read-only
VerticalSeparators Collection of vertical
separator objects
Arguments
IVerticalSeparato
rs, read-only
Bleed
Description : Flow bleed object
Attributes :
IBleed, read-only
Methods
Name
Description
Arguments
Connect(ConnectionIdx As
fntNodeEnd, Pipe As IPipe,
PipeConnectionIdx As
fntPipeEnd)
Connect to a pipe
ConnectionIdx = Connection
on bleed
Disconnect(ConnectionIdx
As fntNodeEnd)
Disconnect from a
pipe
Pipe = Pipe to connect to
PipeConnectionIdx =
Connection on pipe
on bleed
Properties
Name
Description
Attributes
Arguments
PropertyByName(Wha Property value for a
t As String)
named property
Variant, read/write What = Property
name
PropertyNames
String, read-only
Collection of all the
property names
Named Properties For PropertyByName()
Name
Units
Attributes
Ignored
fntYesNo, read/write
Location
String, read/write
Name
String, read/write
OfftakeMaximum
kg/hr
OfftakeMinimum
kg/hr
OfftakeMultiplier
Double, read/write
Double, read/write
Double, read/write
OfftakeOffset
kg/hr
Double, read/write
PressureDrop
bar
Double, read/write
Bleeds
Description : Collection of flow bleed objects
Attributes :
128
IBleeds, read-only
8 Automation
Methods
Name
Description
Arguments
Add ([Name As String],
[Xcoordinate As Single =
0] [Ycoordinate As Single
= 0])
Add a new
bleed
Name: If omitted a new name is
automatically generated
Xcoordinate = X coordinate on the
Process Flowsheet (Twips)
Ycoordinate = Y coordinate on the
Delete (What)
Delete a bleed
What = Index as Name (String) or
Number (Integer/Long)
Properties
Name
Description
Attributes
Count
Number of items in the
collection
Long, read-only
Item
(What)
Indexed item in the
collection
IBleed, readonly
Arguments
What = Index as Name
(String) or Number
(Integer/Long)
Component
Description : Component object
Attributes :
IComponent, read-only
Methods
Name
Description
Arguments
Clear (Optional Cname Clear all component data
compName As String
= Nothing)
EstimateUnknown
Cname = Component
Name. If omitted all
components will be
cleared.
Estimate all unknown component data
Properties
Name
Description
Attributes
IsValid
Validate component
data is complete
Boolean, read-only
Arguments
PropertyByName(W Property value for a
hat As String)
named property
Variant, read/write What = Property
name
PropertyNames
String, read-only
property names
Name
Units
AcentricFactor
Double, read/write
AcentricFactorSrk
CharacteristicVolume
8 Automation
Attributes
Double, read/write
m3/kgmole
Double, read/write
CriticalPressure
bar abs
Double, read/write
CriticalTemperature
K
Double, read/write
129
Name
Units
Attributes
CriticalVolume
m3/kgmole
Double, read/write
EnthalpyCoefficients
kJ/kgmole
Double(1 To 6), read/write
kJ/kgmole/K
kJ/kgmole/K2
kJ/kgmole/K3
kJ/kgmole/K4
kJ/kgmole/K5
EntropyCoefficient
Double, read/write
Id
Integer, read/write
MolecularWeight
Double, read/write
Name
String, read/write
NormalBoilingPoint
K
Double, read/write
StandardDensity
kg/m3
Double, read/write
Type
fntCompType, read/write
WatsonK
Double, read/write
ViscosityCoefficient
Double(1 To 2), read/write
Components
Description : Collection of component objects
Attributes :
IComponents, read-only
Methods
Name
Description
Arguments
AddLibrary(What As
Variant)
Add a library
component
What = Component identifier as
either name (String) or ID
(Integer/Long)
AddHypothetical(What
As String)
Add a named
hypothetical component
What = Name for new
component
Delete(What)
Delete a component
What = Index as component as
either Name (String) or Number
(Integer/Long)
Properties
Name
Description
Attributes
Count
Number of items in
the collection
Long, read-only
Item(What)
Indexed item in the
collection
IComponent,
read-only
Arguments
(String) Or Number
(Integer/Long)
Connector
Description : Connector node object
Attributes :
130
IConnector, read-only
8 Automation
Methods
Name
Description
Arguments
Connect(ConnectionIdx
As fntNodeEnd, Pipe As
IPipe, PipeConnectionIdx
As fntPipeEnd)
Connect to a pipe
ConnectionIdx = Connection on
connector
As fntNodeEnd)
Disconnect from a
pipe
PipeConnectionIdx = Connection
on pipe
connector
Properties
Name
Description
Attributes
Arguments
PropertyByName(W Property value for a
hat As String)
named property
Variant,
read/write
What = Property name
PropertyNames
String, read-only
property names
Name
Units
Attributes
Angle
radians
Double, read/write
Ignored
Length
m
Double, read/write
Location
String, read/write
Name
String, read/write
Connectors
Description : Collection of connector objects
Attributes :
IConnectors, read-only
Methods
Name
Description
Arguments
= 0])
Add a new
connector
Delete (What)
Delete a connector
Properties
8 Automation
Name
Description
Attributes
Count
collection
Long, read-only
Item(What)
Indexed item in the
collection
IConnector, readonly
Arguments
What = Index as
Name (String) Or
Number
(Integer/Long)
131
ControlValve
Description : Control valve object
Attributes :
IControlValve, read-only
Methods
Name
Description
Arguments
As fntPipeEnd)
Connect to a pipe
control valve
As fntNodeEnd)
Disconnect from a
pipe
PipeConnectionIdx = Connection
on pipe
control valve
Properties
Name
Description
PropertyByName(W Property value for
hat As String,
a named property
Attributes
Arguments
Variant,
read/write
Scenario = Scenario Index
as Name (String) or
[Scenario])
PropertyNames
Collection of all
the property
names
String, read-only
Name
Units
Attributes
Composition
fractions
Double (1 To ?), read/write
CompositionBasis
Energy
132
fntCompBasis, read/write
kJ/hr
Double, read-only
Enthalpy
kJ/kgmole
Double, read-only
Entropy
kJ/kgmole/K
Double, read-only
FlangeDiameter
mm
Double, read/write
FluidType
fntCompType, read/write
Ignored
Location
String, read/write
LockMabp
Mabp
bar abs
Double, read-only
MassFlow
kg/hr
Double, read/write
MolecularWeight
Double, read/write
Name
String, read/write
OutletMachNumber
Double, read-only
OutletSonicVelocity
m/s
Double, read-only
OutletTemperature
C
Double, read-only
OutletTemperatureSpecification
C
Double, read-only
OutletVelocity
m/s
Double, read-only
ReliefPressure
bar abs
Double, read-only
StaticOutletPressure
bar abs
Double, read-only
8 Automation
Name
Units
Attributes
StaticInletPipePressureDrop
bar
Double, read-only
Temperature
C
Double, read-only
TemperatureSepcification
fntTempSpec, read/write
TotalOutletPressure
bar abs
Double, read-only
TotalInletPipePressureDrop
bar
Double, read-only
VapourFraction
molar fraction
Double, read-only
ControlValves
Description : Collection of control valve objects
Attributes :
IControlValves
Methods
Name
Description
Arguments
= 0])
Add a new
control valve
Delete(What)
Delete a control
valve
Properties
Name
Description
Attributes
Count
Number of items in
the collection
Long, read-only
Item(What) Indexed item in the
collection
Arguments
IControlValve,
read-only
(String) or Number
(Integer/Long)
HorizontalSeparator
Description : Horizontal separator object
Attributes :
IHorizontalSeparator, read-only
Methods
Name
Description
Arguments
As fntPipeEnd)
Connect to a pipe
horizontal separator
As fntNodeEnd)
Disconnect from
a pipe
PipeConnectionIdx = Connection on
pipe
horizontal separator
Properties
8 Automation
133
Name
Description
Attributes
Arguments
PropertyByName(
What As String)
Property value for a named
property
Variant,
read/write
What = Property
name
PropertyNames
Collection of all the property
names
String, readonly
Name
Units
Attributes
Diameter
mm
Double, read/write
Ignored
LiquidLevel
mm
Double, read/write
Location
String, read/write
Name
String, read/write
HorizontalSeparators
Description : Collection of horizontal separator objects
Attributes :
IHorizontalSeparators, read-only
Method
Name
Description
Arguments
Add ([Name As
String],
[Xcoordinate As
Single = 0]
[Ycoordinate As
Single = 0])
Add a new
horizontal
separator
Delete(What)
Delete a horizontal
separator
Properties
Name
Description
Attributes
Arguments
Count
Number of items
in the collection
Long, read-only
Item(What)
Indexed item in
the collection
IHorizontalSepar What = Index as Name (String)
ator, read-only
Or Number (Integer/Long)
Nodes
Description : Collection of all node objects
Attributes :
INodes, read-only
Properties
134
Name
Description
Attributes
Count
collection
Long, read-only
Arguments
8 Automation
OrificePlate
Description : Orifice plate object
Attributes :
IOrificePlate, read-only
Method
Name
Description
Arguments
As fntPipeEnd)
Connect to a
pipe
orifice plate
As fntNodeEnd)
Disconnect from
a pipe
pipe
orifice plate
Properties
Name
Description
PropertyByName Property value for a
(What As String) named property
PropertyNames
Attributes
Arguments
Variant,
read/write
Variant array of all the Variant, read-only
property names
Name
Units
Attributes
Diameter
mm
Double, read/write
DratioIn
Double, read/write
DratioOut
Double, read/write
Ignored
Location
String, read/write
Name
String, read/write
OrificePlates
Description : Collection of orifice plate objects
Attributes :
IOrificePlates, read-only
Methods
Name
Description
Arguments
= 0])
Add a new
orifice plate
Delete(What)
Delete an orifice
plate
Properties
8 Automation
135
Name
Description
Attributes
Count
collection
Long, read-only
Item(Wha Indexed item in the
t)
collection
Arguments
IOrificePlate, readonly
What = Index as
Name (String) Or
Number
(Integer/Long)
Pipe
Description : Pipe object
Attributes :
IPipe, read-only
Methods
Name
Description
Arguments
AddFitting(FittingName
As String, [Count As
Long = 1])
Add a fitting to the
fittings list
FittingName = Name of
fitting defined in the pipe
fittings database
Count = Number of fittings
of this type to add
as fntPipeEnd, Node As
Object,
NodeConnectionIdx as
fntNodeEnd)
Connect to a node
ConnectionIdx =
Connection on pipe
DeleteAllFittings()
Delete all fittings
from the fittings list
DeleteFittingByIndex(Fi
ttingIndex As Long)
Delete a fitting from
the fittings list
FittingIndex = Index of
fitting in the fittings list to
delete
DeleteFittingByName(Fi
ttingName As String,
[Count As Long = 1])
Delete a fitting from
the fittings list
FittingName = Name of
fitting defined in the pipe
fittings database
Node = Node to connect to
NodeConnectionIdx =
Connection on node
Count = Number of fittings
of this type to delete
Disconnect(ConnectionI
dx As fntPipeEnd)
Disconnect from a
node
GetFittingCount() As
Long
Get number of
fittings in the fitting
list
GetFittingName(FittingI
ndex As Long) As
String
Get name of indexed
pipe fitting
ConnectionIdx =
Connection on pipe
FittingIndex = Index of
fitting in the fittings list to
retrieve name for
Properties
136
8 Automation
Name
Description
Attributes
Arguments
PropertyByName(
What As String,
Property value for a
named property
Variant,
read /write
[Scenario],
[Phase],
[PipeEnd])
Scenario = Scenario Index as
Name (String) or Number
(Integer/Long)
Phase = Phase Index
(fntFluidPhase)
PipeEnd = Pipe end
(fntPipeEnd)
PropertyNames
property names
String, readonly
UseFittings
Flag to indicate if a
fittings list is used
instead of loss
coefficients
Boolean,
read/write
Name
Units
Attributes
AccelerationPressureDrop
bar
Double, read-only
AmbientTemperature
C
Double, read-only
CanSize
MoleFractions
Double(1 To ?), readonly
Density
kg/m3
Double, read-only
Duty
kJ/hr
Double, read-only
ElevationChange
m
Double, read/write
ElevationPressureDrop
bar
Double, read-only
Emissivity
kJ/hr
Double, read-only
Enthalpy
kJ/kgmole
Double, read-only
Entropy
kJ/kgmole/K
Double, read-only
EquivalentLength
m
Double, read-only
ExternalDuty
W
Double, read/write
ExternalHeatTransferCoefficient
W/m2/K
Double, read-only
ExternalRadiativeHeatTransferCoefficient
W/m2/K
Double, read-only
ExternalTemperature
C
Double, read-only
FittingsLossConstant
Double, read-only
FittingsLossMultiplier
Double, read-only
FittingsPressureDrop
8 Automation
Double, read-only
Energy
bar
Double, read-only
FlowRegime
fntFlowRegime, readonly
FrictionFactor
Double, read-only
FrictionPressureDrop
bar
Double, read-only
HeatCapacity
kJ/kgmole/K
Double, read-only
HeatTransfer
kJ/hr
Double, read-only
Ignored
IgnoreHeadRecovery
137
Name
Units
InsulationName
Attributes
String, read/write
InsulationThickness
mm
Double, read/ write
InsulationThermalConductivity
W/m/K
Double, read/write
InternalDiameter
mm
Double, read/write
Length
m
Double, read/write
LengthMultiplier
Double, read/write
Location
String, read/write
MachNumber
Double, read-only
MassFlow
kg/hr
Material
MolecularWeight
MolarFlow
Double, read-only
kgmole/hr
Name
Noise
Double, read/write
fntPipeMaterial,
read/write
Double, read-only
String, read/write
dB
NominalDiameter
Double, read-only
String, read/write
C
Double, read/write
OverallHeatTransferCoefficient
W/m2/K
Double, read-only
UsePipeClass
PhaseFraction
Double, read-only
PressureDrop
bar
RatedMassFlow
kg/hr
ReynoldsNumber
Double, read-only
Double, read-only
Double, read-only
RhoV2
kg/m/s2
Roughness
mm
Double, read/write
StaticPressure
bar abs
Double, read-only
Schedule
SurfaceTension
Double, read-only
String, read/write
dynes/cm
TailPipe
Double, read-only
Temperature
C
Double, read-only
ThermalConductivity
W/m/K
Double, read-only
TotalPressure
bar abs
Double, read-only
VapourFraction
molar fraction Double, read-only
Velocity
m/s
Double, read-only
Viscosity
cP
Double, read-only
WallThermalConductivity
W/m/K
Double, read/write
WallTemperature
C
Double, read-only
WallThickness
mm
Double, read/write
WindSpeed
m/s
Double, read/write
Zfactor
Double, read-only
Pipes
Description : Collection of pipes
138
8 Automation
Attributes :
IPipes
Methods
Name
Description
Arguments
= 0])
Add a new
pipe
Delete(What)
Delete a pipe
Properties
Name
Description
Attributes
Count
collection
Long, read-only
Item(Wha Indexed item in the
t)
collection
IPipe, read-only
Arguments
(String)
or Number (Integer/Long)
ReliefValve
Description : Relief valve object
Attributes :
IReliefValve, read-only
Methods
Name
Description
Arguments
pipeConnectionIdx As
fntPipeEnd)
Connect to a
pipe
ConnectionIdx = Connection on relief
valve
As fntNodeEnd)
Disconnect
from a pipe
pipe
ConnectionIdx = Connection on relief
valve
Properties
Name
Description
(What As String, named property
Attributes
Arguments
Variant,
read/write
[Scenario])
PropertyNames
property names
Scenario = Scenario
Index as Name (String)
or Number
(Integer/Long)
String, read-only
8 Automation
Name
Units
Attributes
Composition
fractions
Double (1 To ?),
read/write
139
Name
Units
CompositionBasis
fntCompBasis,
read/write
Contingency
fntContingency,
read/write
Energy
kJ/hr
Double, read-only
Enthalpy
kJ/kgmole
Double, read-only
Entropy
kJ/kgmole/K
Double, read-only
FlangeDiameter
mm
Double, read/write
FluidType
fntCompType,
read/write
HemCd
Double, read/write
HemLiqCd
Double. Read/write
Ignored
Kb
Double, read/write
Location
String, read/write
LockMabp
LockReliefPressure
LockRatedMassFlow
Mabp
bar abs
MassFlow
kg/hr
Double, read/write
Mawp
bar abs
Double, read/write
MechanicalPressure
bar abs
Double, read/write
Double, read-only
MolecularWeight
Double, read/write
Name
String, read/write
Orifice
String, read/write
OutletMachNumber
OutletSonicVelocity
Double, read-only
m/s
Double, read-only
OutletTemperature
C
Double, read-only
C
Double, read-only
OutletVelocity
m/s
Double, read-only
RatedMassFlow
kg/hr
Double, read/write
ReliefPressure
bar abs
Double, read-only
SizingBackPressure
Bar abs
Double, read/write
SizingMethod
StaticOutletPressure
Integer, read/write
bar abs
Double, read-only
StaticInletPipePressureDrop
bar
Double, read-only
Temperature
C
Double, read-only
TemperatureSpecification
140
Attributes
fntTempSpec,
read/write
TotalOutletPressure
bar abs
Double, read-only
TotalInletPipePressureDrop
bar
Double, read-only
ValveArea
mm2
Double, read/write
ValveCount
Integer, read/write
ValveType
fntPsvType, read/write
8 Automation
Name
Units
Attributes
VapourFraction
molar fraction Double, read-only
ReliefValves
Description : Collection of relief valve objects
Attributes :
IReleifValves
Methods
Name
Description
Arguments
= 0])
Add a new relief
valve
Xcoordinate = X coordinate on
the Process Flowsheet (Twips)
Ycoordinate = Y coordinated on
the Process Flowsheet (Twips)
Delete(What)
Delete a relief valve
What = Index as Name (String)
or Number (Integer/Long)
Properties
Name
Description
Attributes
Count
Number of items in
the collection
Long, read-only
Item(What)
Indexed item in the
collection
IReliefValve,
read-only
Arguments
(String) or Number
(Integer/Long)
Scenario
Description : Scenario object
Attributes :
IScenario, read-only
Properties
Name
Description
PropertyNames
Attributes
Arguments
Variant,
read/write
Variant array of all the String, read-only
property names
Name
Units
Attributes
AtmosphericPressure
bar abs
Double, read/write
m/s
Double, read/write
Calculate
HeaderLiquidVelocityLimit
HeaderMachLimit
8 Automation
Double, read/write
HeaderNoiseLimit
dB
Double, read/write
HeaderRhoV2Limit
kg/m/s2
Double, read/write
141
Name
Units
Attributes
HeaderVapourVelocityLimit
m/s
Double, read/write
m/s
Double, read/write
TailpipeNoiseLimit
dB
Double, read/write
TailpipeRhoV2Limit
kg/m/s2
Double, read/write
TailpipeVapourVelocityLimit
m/s
Double, read/write
Name
String, read/write
TailpipeLiquidVelocityLimit
TailpipeMachLimit
Double, read/write
Scenarios
Description : Collection of scenario objects
Attributes :
IScenarios, read-only
Methods
Name
Description
Arguments
Add([Name As
String],
Add a new scenario
Name = New scenario name
CloneIdx = Index of scenario to copy data
from for initialization
[CloneIdx As
Long = 1])
Delete(What)
Delete a scenario
What = Index as Name (String) or Number
(Integer/Long)
Name
Description
Attributes
Active
Set active scenario
ActiveScenario
Get active scenario
Count
Number of items in the Long, read-only
collection
Item(What)
Indexed item in the
collection
Properties
Arguments
(String) or Number
(Integer/Long)
IScenario, readonly
IScenario, readonly
(String) or Number
(Integer/Long)
Solver
Description : Solver object
Attributes :
ISolver, read-only
Methods
Name
Description
Halt
Stop calculations
Start
Start calculations
Arguments
Properties
142
8 Automation
Name
Description
Attributes
Arguments
IsActive
Get calculation status
Boolean, readonly
PropertyByName(
What As String)
named property
Variant,
read/write
PropertyNames
property names
String, read-only
What = Property
name
Name
Units
Attributes
AmbientTemperature
C
Double, read/write
AtmosphericPressure
bar abs
Double, read/write
CalculationMode
fntCalcMode, read/write
CheckChokedFlow
Elements
Integer, read/write
EnableHeatTransfer
EnthalpyMethod
fntEnthMethod,
read/write
InitialPressure
bar abs
Double, read/write
KineticEnergyBasis
fntKeBasis, read/write
LengthMultiplier
Double, read/write
LoopIteration
Integer, read-only
LoopIterationLimit
Integer, read/write
LoopTolerance
%
Double, read/write
PressureDropMethod
fntPresDropMethod(0 to
2), read/write
PropertyIteration
Integer, read-only
PropertyIterationLimit
Integer, read/write
PropertyTolerance
%
ScenarioMode
Double, read/write
fntScenarioMode,
read/write
UnitOperationTolerance
%
Double, read/write
UseKineticEnergy
UseRatedFlow
VleMethod
fntVleMethod,
read/write
WindSpeed
Double, read/write
Tee
Description : Tee object
Attributes :
ITee, read-only
Methods
Name
8 Automation
Description
Arguments
143
Name
Description
Arguments
fntPipeEnd)
Connect to a pipe
ConnectionIdx =
Connection to tee
As fntNodeEnd)
Disconnect from a pipe
PipeConnectionIdx =
Connection on pipe
ConnectionIdx =
Connection on tee
Properties
Name
Description
Attributes
Arguments
PropertyByName(
What As String)
named property
Variant,
read/write
PropertyNames
property names
String, read-only
Name
Units
Attributes
Angle
fntTeeAngle, read/write
Body
fntTeeEnd, read/write
Ignored
Location
String, read/write
Name
String, read/write
Tees
Description : Collection of tee objects
Attributes :
ITees, read-only
Method
Name
Description
Arguments
= 0])
Add a new tee
Delete(What)
Delete a tee
Properties
144
Name
Description
Attributes
Count
Number of items in
the collection
Long, read-only
Item(What)
Indexed item in the
collection
ITee, read-only
Arguments
(String) Or Number
(Integer/Long)
8 Automation
Tip
Description : Flare tip object
Attributes :
ITip, read-only
Methods
Name
Description
AddCurve()
Add a pressure drop
curve
AddCurvePoint(Index As Long)
Append a point to a
pressure drop curve
Index = Index of curve
fntPipeEnd)
Connect to a pipe
ConnectionIdx =
Connection to tee
DeleteCurve(Index As Long)
Delete a pressure drop
curve
PipeConnectionIdx =
Connection on pipe
DeleteCurvePoint(Index As Long,
Which As Long)
Disconnect(ConnectionIdx As
fntNodeEnd)
Arguments
Which = Index of point
Disconnect from a pipe
ConnectionIdx =
Connection on flare tip
Properties
Name
Description
CurveMolWt(Inde Molecular weight of
x As Long)
indexed pressure drop
curve
Attributes
Arguments
Double, read/write Index = Curve index
CurvePointMassF Mass flow of point on a Double, read/write Index = Index of curve
low(Index As
pressure drop curve
Long, Which As
(kg/hr)
Long)
CurvePointPressu Pressure drop of point
reDrop(Index As on a pressure drop
Long, Which As
curve (bar)
Long)
Double, read/write Index = Index of curve
Variant,
read/write
PropertyNames
String, read-only
property names
8 Automation
Name
Units
Diameter
mm
Attributes
Double, read/write
Ignored
K
Double, read/write
Kbasis
fntKbasis, read/write
Location
String, read/write
Name
String, read/write
Reference Temperature
Double, read/write
145
Name
Units
Attributes
UseCurves
Tips
Description : Collection of flare tip objects
Attributes :
ITips, read-only
Methods
Name
Description
Arguments
Add ([Name As
String], [Xcoordinate
As Single = 0]
[Ycoordinate As Single
= 0])
Add a new
flare tip
Delete(What)
Delete a flare
tip
Properties
Name
Description
Attributes
Arguments
Count
Number of items in
the collection
Long, read-only
Item(What)
Indexed item in the
collection
ITip, read-only
(String) Or Number
(Integer/Long)
VerticalSeparator
Description : Vertical separator object
Attributes :
IVerticalSeparator, read-only
Methods
Name
Description
Arguments
fntPipeEnd)
Connect to a pipe
on vertical separator
As fntNodeEnd)
Disconnect from a
pipe
PipeConnectionIdx =
Connection on pipe
on vertical separator
Properties
Name
146
Description
Attributes
Arguments
Variant,
read/write
PropertyNames
String, read-only
property names
8 Automation
Name
Units
Attributes
Diameter
mm
Double, read/write
Ignored
Boolean, read/write
Location
String, read/write
Name
String, read/write
VerticalSeparators
Description : Collection of vertical separator objects
Attributes :
IVerticalSeparators, read-only
Methods
Name
Description
Arguments
= 0])
Add a new
vertical
separator
Delete(What)
Delete a vertical
separator
Properties
Name
Description
Attributes
Arguments
Count
Number of items in
the collection
Long, read-only
Item(What)
Indexed item in the
collection
IVerticalSeparator What = Index as Name
, read-only
(String) Or Number
(Integer/Long)
Example – Automation In
Visual Basic
This example shows how that Aspen Flare System Analyzer can be used as an
automation server by a program that analyses an Aspen Flare System
Analyzer model to search for the maximum and minimum values of a user
defined named property within all the pipes.
Note: Although Visual Basic 6 is recommended for this example, you may
create the Automation application in the Visual Basic editor provided in
Microsoft Excel 2007® (or later) and Microsoft Word 2007® (or later).
1
8 Automation
Open a new project in Visual Basic 6®. From the New tab of the New
Project property view; select the Standard EXE icon and click OK. Your
screen should appear similar as below.
147
Fig 8.6
2
By default you should have a form associated with th
the
e project. In the
Name field of the Properties window, give the form the name:
frmBounds.
Note: This complete example has also been pre
pre-built
built and is located in the
\Samples\Ole\Vb
Vb\Bounds directory.
148
3
In the Caption field typ
type: Aspen Flare System Analyzer Model Pipe
Property Bounds
Bounds.. This caption should now appear in the title bar of the
form.
4
Before adding objects to the for
form,, resize the view to accommodate the
different objects that will be rrequired. In the Width filed found in the
Properties w
window, change the width of the form to 6900
00 or to any
value such that the form is sufficiently wide to fully display the caption.
5
From the Tool Box select Text Box; create
te a text box on the form as
shown below..
8 Automation
Fig 8.7
6
Ensure that the text box is the active control. This can be done in one of
two ways:
Select the text box on the form so that the object guides appear around
the object.
From the box found at the top of the Properties window, select the name
of the text box you have just created.
8 Automation
7
In the Properties windows, set the name of the text box as
ebModelName in the Name field. If you wish, you may also
lso change the
default text that appears inside the edit box by entering a new name in
the Text field.
8
You may add a label to the form. i.e. to identify the object from others, by
selecting the Label tool and drawing the label
abel on the form just above the
text box you have just created.
9
Ensuring that the label control is active using one of the methods
suggested in step 6, go to the Properties Window and change the text
in the Caption field to Model Name.
149
Fig 8.8
10 Add the following objects to the form using the previously described
methods.
Fig 8.9
11 Only two more objects are required on the form. Select the Command
Button control from the tool bar and add two buttons to the form as
shown below.
150
8 Automation
Fig 8.10
12 You are now ready to begin defining the events behind the form and
objects. You may enter the code environment using a number of methods:
methods
Click View Code in the Project window.
Select Code from the View menu.
Double-click
click the frmBounds form.
8 Automation
151
Fig 8.11
The Private Sub Form_Load() method definition will only be visible if
you enter the code environment by double
double-clicking
clicking the form.
13 Begin by declaring the following variables under the Option Explicit
Declaration.
Fig 8.12
14 Add a reference to the Aspen Flare System Analyzer type library to allow
access to predefined constant
constants by selecting References from the Project
menu.
152
8 Automation
Fig 8.13
15 The first subroutine should already be declared. The Form_Load
subroutine is the first subroutine called once the program is run. It is
usually used to initializ
initialize
e the variables and objects used by the program.
Enter the following code into the Form_Load subroutine.
Code
Explanation
Private Sub
Form_Load()
Signifies the start of the form load subroutine.
You do not have to add as it should already be
there.
ebModelName.Text
elName.Text = ""
ebPropertyName.Text =
""
ebMinValue.Text = ""
ebMaxValue.Text = ""
End Sub
Clears all the text fields.
Signifies the end of the initialization subroutine.
This line does not need to be added.
16 The next section
ection of code to be added is what will occur when the name of
the model is changed in the ebModelName box.
Code
Private Sub
ebModelName_Validate(Cancel
As Boolean)
8 Automation
Explanation
Signifies the start of the subroutine.
ModelName = ebModelName.Text
Copies the
e entered name for the model
to the String Variable ModelName
End Sub
Signifies the end of the subroutine.
153
17 The next section of code to be added is what will occur when the desired
property is changed in the ebPropertyName box.
Code
Private Sub
ebPropertyName_Validate(Canc
el As Boolean)
Explanation
PropertyName =
ebPropertyName.Text
Copies the entered name for the
property to the String Variable
PropertyName
End Sub
18 The final two routines define the actions of the two buttons: btnUpdate
and btnExit.
Code
Explanation
Private Sub btnUpdate_Click()
Dim OwnedByMe As Boolean
Dim MaxVal As Double
Dim MinVal As Double
Dim Pipe As
AspenTech.FlareSystemAnalyzer.I
nterfacesObject
Dim iPipe As Long
Dim npipes As Long
Dim WorkVal As Double
On Error Resume Next
If Trim$(ModelName) = "" Then
OwnedByMe = False
Set FnApp = GetObject(,
"AspenTech.FlareSystemAnalyzer.
Interfaces.Application")
Else
Set FnApp =
CreateObject("AspenTech.FlareSy
stemAnalyzer.Interfaces.Applica
tion")
OwnedByMe = True
FnApp.OpenModel ModelName
End If
Prevents an error from being raised
if, for example, an invalid name for
the property is selected.
If a model name is defined then
opens the model defined by the
String variable ModelName;
otherwise, connects to the currently
running instance of Aspen Flare
System Analyzer.
If Not FnApp Is Nothing Then
Ensure successful connection to the
Application object.
MaxVal = -10000000000#
MinVal = 10000000000#
Initializes the maximum and
minimum values to values outside
the range of possible values.
npipes = FnApp.Pipes.Count
For iPipe = 1 To npipes
Set pipe =
FnApp.Pipes.Item(iPipe)
154
Declare work variables.
Loop through all the pipes in the
model.
8 Automation
Code
Explanation
WorkVal =
Pipe.PropertyByName(PropertyNam
e)
Get the property named and stores
in the String variable
PropertyName.
If WorkVal <>
fntVariableStatus_fntUnknownVal
ue Then
Check for an unknown value. Do not
consider the value further if it is
unknown.
If WorkVal > MaxVal Then MaxVal
= WorkVal
If WorkVal < MinVal Then MinVal
= WorkVal
Update minimum value.
End of loop and value update.
End If
Next iPipe
ebMinValue.Text
Format$(MinVal,
ebMaxValue.Text
Format$(MaxVal,
Update maximum value.
=
"0.000e+00")
=
"0.000e+00")
Disconnect the Application object.
Set FnApp = Nothing
End If
End Sub
Private Sub
btnExit_Click()
Set FnApp = Nothing
Unload Me
End
End Sub
Update the displayed values in the
ebMinValue and ebMaxValue Text
boxes.
Releases the connection to Aspen Flare
System Analyzer.
Unload the form and end the program.
19 You are now ready to compile and run the program. Before you begin,
please ensure that you have a copy of Aspen Flare System Analyzer on
the computer.
20 To compile the program do one of the following:

Click the Start button...

Select Start from the Run menu.

Press <F5> from the keyboard.
Visual Basic will inform you of any errors that occur during compile time.
Updating Automation Files
From Previous Versions
Aspen Flare System Analyzer now uses a new .Net interface to provide access
to the software via automation. As a result a few changes have to be made in
the way the VB6 application code accesses the available methods and
properties. If you have an existing application, it may fail to run with the new
8 Automation
155
interface. Below are some notes on what needs to be updated in your
applications to ensure it runs successfully in this new version.
156
1
Currently Application.Visible can only be set to False. The user
cannot make the application visible. The application will be running as
usual in the background. The LaunchFlarenet method described in this
chapter can be used to launch a separate process showing the graphical
user interface. This process can only be controlled manually and needs to
be manually terminated as well.
2
In the declarations Integer should be replaced by Long.
3
Objects cannot be enumerated in a collection. Previously you could write
the following code:
Dim Pipe As Object
For Each Pipe In FnApp.Pipes
WorkVal = Pipe.PropertyByName(PropertyName)
…
Next
Now this type of code must be written as follows:
Dim iPipe As Long
Dim npipes As Long
For iPipe = 1 To npipes
Set pipe = FnApp.Pipes.Item(iPipe)
WorkVal = pipe.PropertyByName(PropertyName)
…
Next iPipe
4
In VB6 enum values are actually constants, thus Enum members can be
used directly without the Enum type, e.g. fntUnknownValue. In VB.Net
the Enum type is just a type, not a constant. Also in VB6 it is not possible
to have items of the same name under different Enums, e.g.
fntFlowRegime.fntUnknownValue and
fntVariableStatus.fntUnknownValue. Therefore to avoid this issue,
MicroSoft determines that all Enum items should be renamed by having
their Enum type as prefix followed by character _. Thus existing code
must be modified to include the new Enum item names. For instance,
instead of fntUnknownValue for Variable Status, we now have
fntVariableStatus_fntUnknownValue. Please look in the
AspenTech.FlareSystem.Analyzer Object Browser for the new Enum items’
names.
8 Automation
9 Theoretical Basis
Pressure Drop
Pipe Pressure Drop Method
Vapor Phase Pressure Drop Methods
Pressure drop can be calculated either from the theoretically derived equation
for isothermal flow of a compressible fluid in a horizontal pipe2:


2
2
 L  G 
 G   P1  M P2  P1
 2 f f     0
  In   
2 RT
 a   P2 
   a 
2
2
9.1
where :
G  Mass flow
a  Cross sectional area of pipe
P1  Upstream pressure
P2  Downstream pressure
R  Universal gas constant
f f  Fanning friction factor
  Internal diameter
L  Equivalent length
T  Temperature
M  Molecular weight
9 Theoretical Basis
157
Or from the theoretically derived equation for adiabatic flow of a compressible
fluid in a horizontal pipe2:
2
 L   γ - 1 P1  a    V1 
Af f    
   1   
    2γ V1  G    V2 
2
 γ  1  V 
In 2 

γ

 V1 
9.2
where :
G  Mass flow
a  Cross sectional area of pipe
P1  Upstream pressure
R  Universal gas constant
V1  Upstream specific volume
V2  Downstream specific volume
γ  Ratio of specific heats
The friction factor is calculated using an equation appropriate for the flow
regime. These equations correlate the friction factor to the pipe diameter,
Reynolds number and roughness of the pipe4:
Turbulent Flow (Re > 4000)
The friction factor may be calculated from either the Round equation:
1
ff

Re
 3.61 log 
e
 0.135 Re  6.5





9.3
where :
Re  Reynolds number
e  Absolute pipe roughness
Or from the Chen21 equation:
1
ff
158
0.8981
1.1098
 e / 

5.0452  e /  
 7.149 

 4 log

log




3
.
7065
Re
2
.
8257
Re





9 Theoretical Basis
9.4
where :
Transition Flow (2100  Re  4000)
1
ff
 e  5.02  e  5.02  e
13.0 
 
 

 4.0 log
log
log

 3.7  Re
 3.7 Re 
 3.7  Re
9.5
where :
Laminar Flow (Re < 2100)
ff 
16
Re
9.6
where :
The Moody friction factor is related to the Fanning friction factor by:
fm  4  f f
9.7
where :
f m  Moody friction factor
9 Theoretical Basis
159
2-Phase Pressure Drop
Although the Beggs and Brill method was not intended for use with vertical
pipes, it is nevertheless commonly used for this purpose, and is therefore
included as an option for vertical pressure drop methods.
Beggs and Brill
The Beggs and Brill9 method is based on work done with an air-water mixture
at many different conditions, and is applicable for inclined flow. In the Beggs
and Brill correlation, the flow regime is determined using the Froude number
and inlet liquid content. The flow map used is based on horizontal flow and
has four regimes: segregated, intermittent, distributed and transition. Once
the flow regime has been determined, the liquid hold-up for a horizontal pipe
is calculated, using the correlation applicable to that regime. A factor is
applied to this hold-up to account for pipe inclination. From the hold-up, a
two-phase friction factor is calculated and the pressure gradient determined.
Fig 9.1
The boundaries between regions are defined in terms of two constants and
the Froude number10:

L1  exp  4.62  3.757x  0.481x 2  0.0207x 3
9.8


L2  exp 1.061  4.602x  1.609x 2  0.0179x 3  0.000625x 5
160

9 Theoretical Basis
9.9
where :
x  Inλ 
λ  Input liquid content  q liquid / qliquid  q gas 
q  In situ volumetric flowrate
According to Beggs and Brill:
1
If the Froude number is less than L1, the flow pattern is segregated.
2
If the Froude number is greater than both L1 and L2, the flow pattern is
distributed.
3
If the Froude number is greater than L1 and smaller than L2 the flow
pattern is intermittent.
Dukler Method
The Dukler10 method breaks the pressure drop into three components Friction, Elevation and Acceleration. The total pressure drop is the sum of the
pressure drop due to these components:
PTotal  PF  PE  PA
9.10
where :
PTotal  Total change in pressure
PF  Change in pressure due to friction
PE  Change in pressure due to elevation
PA  Change in pressure due to acceleration
The pressure drop due to friction is:
2
2 f LV m ρ m
PF  TP
144 g c D
9.11
where :
f TP  Two  phase friction factor (determined empirically )
L  Equivalent length of the pipeline ( ft )
Vm  Velocity of the two  phase mixture in pipeline assuming equal
velocity ( ft / s )
ρ m  Density of two  phase mixture (lb / ft 3 )
g c  Gravitational constant (32.2lbm  ft / lbf  s 2 )
D  Inside diameter of pipe ( ft )
9 Theoretical Basis
161
The pressure drop due to elevation is as follows:
PE 
Eh ρ L  H
144
9.12
where :
Eh  Liquid head factor (determined empirically )
ρ L  Liquid density
 H  Sum of
elevation changes
The pressure drop due to acceleration is usually very small in oil/gas
distribution systems, but becomes significant in flare systems:
1
PA 
144 g c A 2
2
2
2
2
 ρ g QGPL


 ρ g QGPL

ρ L QLPL
ρ L QLPL



 cos θ 




 1  RL
RL 
RL 
 1  RL


DS
US
9.13
where :
A  Cross  sectional area
ρ g  Gas density
QGPL  Volume of gas flowing at pipeline temperature and pressure ( ft 3 / hr )
QLPL  Volume of liquid flowing at pipeline temperature and pressure ( ft 3 / hr )
RL  Liquid holdup in pipeline as a percentage of pipeline capacity
θ  Angle of the pipe bend
Orkiszewski Method
The Orkiszewski11,12 method assumes there are four different flow regimes
existing in vertical two-phase flow - bubble, slug, annular-slug transition and
annular-mist.
The bubble flow regime consists mainly of liquid with a small amount of a
free-gas phase. The gas phase consists of small, randomly distributed gas
bubbles with varying diameters. The gas phase has little effect on the
pressure gradient (with the exception of its density).
In the slug flow regime, the gas phase is most pronounced. The gas bubbles
coalesce and form stable bubbles of approximately the same size and shape.
The gas bubbles are separated by slugs of a continuous liquid phase. There is
a film of liquid around the gas bubbles. The gas bubbles move faster than the
liquid phase. At high flow velocities, the liquid can become entrained in the
gas bubbles. The gas and liquid phases may have significant effects on the
pressure gradient.
Transition flow is the regime where the change from a continuous liquid phase
to a continuous gas phase occurs. In this regime, the gas phase becomes
162
9 Theoretical Basis
more dominant, with a significant amount of liquid becoming entrained in the
gas phase. The liquid slug between the gas bubbles virtually disappears in the
transition regime.
In the annular-mist regime, the gas phase is continuous and is the controlling
phase. The bulk of the liquid is entrained and carried in the gas phase.
Orkiszewski defined bubble flow, slug flow, mist flow and gas velocity
numbers which are used to determine the appropriate flow regime.
If the ratio of superficial gas velocity to the non-slip velocity is less than the
bubble flow number, then bubble flow exists, for which the pressure drop is:
2
 VsL 


RL 

P  f tp ρ L
2g c D
9.14
where :
P  Pressure drop (lb / ft 2 per foot of length)
f tp  Two  phase friction factor
ρ L  Liquid density (lb / ft 3 )
VsL  Superficial liquid velocity ( ft / s )
RL  Dimensionless factor dependent on non  slip velocity
g c  Gravitational constant (32.2 lbm  ft / lbf  s 2 )
D  Hydraulic diameter ( ft )
If the ratio of superficial gas velocity to the non-slip velocity is greater than
the bubble flow number, and the gas velocity number is smaller than the slug
flow number, then slug flow exists. The pressure drop in this case is:
 f tp ρ LVns2
P  
 2g c D

  VsL  Vr 

 




  Vns  Vr 


9.15
where :
Vns  Non  slip velocity
Vr  Bubble rise velocity
  Constant
The pressure drop calculation for mist flow is as follows:
V 
2
P  f tp ρ g
9 Theoretical Basis
sg
2gc D
163
9.16
where :
Vsg  Superficial gas velocity ( ft / s )
ρ g  Gas density (lb / ft 3 )
The pressure drop for transition flow is:
P  Ps  1  x Pm
9.17
where :
Ps  Pressure drop for slug flow
Pm  Pressure drop for mixed flow
x  Weighting factor , dependent on mist flow, slug flow, and gas velocity numbers
The pressure drop calculated by the previous equations, are for a one-foot
length of pipe. These are converted to total pressure drop by:
Ptotal 
ρPL
  Qtotal G f 

144 1  
2
  4637 PA p 
9.18
where :
ρ  Density of the flowing regime (lb / ft 3 )
Qtotal  Mass rate of combined liquid / gas (lb / s )
G f  Gas flow rate ( ft 3 / s )
A p  Cross  sectional area of pipe ( ft 2 )
p  Average pressure in segment ( psia )
P  Unit pressure drop (as calculated above)
L  Length of line segment ( ft )
164
9 Theoretical Basis
Fittings Pressure Change Methods
The correlations used for the calculation of the pressure change across a
fitting are expressed using either the change in static pressure or the change
in total pressure. Static pressure and total pressure are related by the
relationship:
Pt  Ps 
ρv 2
2
9.19
In this equation and all subsequent equations, the subscript t refers to total
pressure and the subscript s refers to the static pressure.
Enlargers/Contractions
The pressure change across an enlargement or contraction may be calculated
using either incompressible or compressible methods. For two phase systems
a correction factor that takes into account the effect of slip between the
phases may be applied.
Figure A.2 and A.3 define the configurations for enlargements and
contractions. In these figures the subscript 1 always refers to the fitting inlet
and subscript 2 always refers to the fitting outlet.
Fig 9.2
Fig 9.3
9 Theoretical Basis
165
Fitting Friction Loss Coefficient
The friction loss coefficients for Enlargements & Contractions are given by:
Sudden and Gradual Enlargement
For an enlarger, both Crane & HTFS methods use the same the fittings loss
coefficients which are defined by Crane26. These methods are based on the
ratio of smaller diameter to larger diameter (β).
If  < 45

θ
K1  2.6 sin  1  β 2
 2

2
9.20
Otherwise

K1  1 β 2

2
9.21
where, β is the ratio of smaller diameter to larger diameter
d
β 1
d2
Sudden and Gradual Contraction
For a contraction the fittings loss coefficient in Crane & HTFS methods are
calculated differently for abrupt sudden contractions. Otherwise the
coefficients are same for Crane & HTFS methods. These calculation methods
are as described below:
Crane
The fitting loss coefficient is calculated as per HTFS27. These methods are
based on the ratio of smaller diameter to larger diameter (β).
K1 
K t Cc
σ2
9.22
K t  19.2211σ 2  8.54038σ 2.5  14.24265σ1.5  4.5385σ
 0.39543σ 0.5  0.57806
9.23
where:
d
σ   2
 d1
166



2
9 Theoretical Basis
The contraction coefficient, is defined by

C c  0.0179le 9.6240θ'  0.03614θ' 1  θ'4.79028

0.25
9.24
where :
θ'  θ/180o
HTFS
The fittings loss coefficients are defined by HTFS27. These methods are same
as the previous Crane method (Equations A.22 – A.24) except for sudden
contractions where the contraction coefficient is calculated differently.
If
θ = 180  (Abrupt contraction)
Cc 
1
1  0.411 - σ 
9.25
Incompressible Single Phase Flow
The total pressure change across the fitting is given by:
Pt  K 1
ρ 1v12
2
9.26
where :
p  Total pressure change
K1  Fittings loss coefficient
ρ  Mass density
v  Velocity
Incompressible Two Phase Flow
The static pressure change across the fitting is given by HTFS27
1  2

 K1  1  2 m 1
σ 
2
Ps  
 LO
2ρ l
9.27
2
 LO

9 Theoretical Basis

x g2 ρ l
1  xg

εg ρg
1- εg
2
167
9.28
where :
m  Mass flux
ρ  Phase mass density
ε  Phase void fraction
x  Phase mass fraction
K 1  Fittings loss coefficient
Ps 
K
t

 1  σ 2 m 22 2
 LO
2ρ l
9.29
2
 LO
  L2 1  x g 
2
9.30
 L2  1 
C
1
 2
X X
9.31
 1  xg
X 
 x
 g
 ρ g 
 
 ρ 
 l 
0.5
 ρg
 
 ρl



9.32
ρ
C  l
ρ
 g




0. 5
0. 5
9.33
where :
m  Mass flux
ε  Phase void fraction
K 1  Fittings loss coefficient
168
9 Theoretical Basis
Compressible Single Phase Flow
Ps 

m 12  ρ1

 1
ρ1σ  ρ 2 σ 
9.34
where :
m  Mass flux
The static pressure change across the fitting is calculated using the two-phase
method given in Compressible Two Phase Flow below. The single-phase
properties are used in place of the two-phase properties.
Compressible Two Phase Flow
Ps 
m 12  vE 2

 vE1 

σ  σ

9.35
where :
vE  Equivalent specific volume given by






2

1  xg  

u R  1 

vE  x g v g  u R 1  x g vl  x g 
1 

u R   v g  0.5 


  v   1

  l


9.36
v
u R   H
 vl



0.5
9.37
vH  xg vg  1  xg vl
9 Theoretical Basis
169
9.38
where :
m  Mass flux
The pressure loss comprises two components. These are the contraction of
the fluid as is passed from the inlet to the vena contracta plus the expansion
of the fluid as it passes from the vena contracta to the outlet. In the following
equations the subscript t refers to the condition at the vena contracta.
For the flow from the inlet to the vena conracta, the pressure change is
modeled in accordance with HTFS27 by:

ζ
1
2
vE
m 12 v E1   v Et 
1 

dζ 
1  

v E1
2 P1   v E1  C c σ 2 


9.39
ζ
P
P1
9.40
For the flow from the vena contracta to the outlet the pressure change is
modeled used the methods for Sudden and Gradual Expansion given above.
Tees
Tees can be modeled either by using a flow independent loss coefficient for
each flow path or by using variable loss coefficients that are a function of the
volumetric flow and area for each flow path as well as the branch angle. The
following numbering scheme is used to reference the flow paths.
Fig 9.4
Constant Loss Coefficients
The following static pressure loss coefficients values are suggested by the
API23:
170
9 Theoretical Basis
θ
K13
K 23
K 12
K 31
K 32
K 21
<90o
0.76
0.50
1.37
0.76
0.50
1.37
90o
1.37
0.38
1.37
1.37
0.38
1.37
The selection of the coefficient value is dependent on the angle and the
direction of flow through the tee.
For flow into the run, the loss coefficient for tee is:
θ
K13
K 12
90o
0.38
1.37
<>90o
0.50
1.37
For flow into the branch, the loss coefficient for tee is:
θ
K 21
K 23
90o
1.37
1.37
<>90o
1.37
0.76
For flow into the tail, the loss coefficient for tee is:
θ
K 31
K 23
90o
0.38
1.37
<>90o
0.50
0.76
where : Reference numbers 1,2 and 3 are assigned as shown in Figure A.4
The static pressure change across the fitting is given by:
Ps  K
ρv 2
2
9.41
Variable Loss Coefficients
The loss coefficients are a function of the branch angle, branch area to total
flow area ratio and branch volumetric flow to total volumetric flow ratio.
These coefficients can be determined either from graphical representation by
Miller25 or from the Gardel28 equations. Using these methods, static pressure
changes can be calculated from:
Combining Flow
 ρ1v12

  ρ 3 v32

 

P
 P3 

1
 2
  2

K 13  
2
ρ 3 v2
2
9 Theoretical Basis
171
9.42
 ρ 2v22
  ρ3v32


 P2   
 P3 

 2
  2

K 23  
ρ3v22
2
9.43
Dividing Flow
 ρ 3v32
  ρ1v12





P


P

3
1
  2
2

 

K 31  
ρ3v22
2
9.44
K 32
 ρ 3 v32
  ρ 2 v 22


 

P
 P2 

3
 2

  2

2
ρ 3 v2
2
9.45
Miller Method
A typical Miller chart for
K 23
in combining flow is shown.
Fig 9.5
Gardel Method
172
9 Theoretical Basis
These coefficients can also be calculated analytically from the Gardel28
Equations given below:
 Combining flow:




 cos 

1
2
K 13  0.921  q r    1.2   
 1  0.81  2
 

 

 2   q r 1  q r 


cos   2
  1   
 qr
 



 2
 cos 

2
K23  0.031  qr   1  1.62   
 1  0.381    q r
 



 2   q r 1  q r 
9.46
 Dividing Flow
 

0.4  0.1 
  2
2


K 31  0.951  q r   1.3 tan   0.3 
1

0
.
9
 qr

2
 
2


 
 1
 0.41   tan  q r 1  q r 
2
 


K 32  0.03 1  q r  0.35q r  0.2q r 1  q r 
2
2
9.47
Where,
qr = Ratio of volumetric flow rate in branch to total volumetric flow rate
Φ = Area ratio of pipe connected with the branch to the pipe carrying the
total flow
ρ = Ratio of the fillet radius of the branch to the radius of the pipe connected
with the branch
θ = Angle between branch and main flow as shown in Fig 9.4
Orifice Plates
Orifice plates can be modeled either as a sudden contraction from the inlet
pipe size to the orifice diameter followed by a sudden expansion from the
orifice diameter to the outlet pipe size or by using the HTFS equation for a
thin orifice plate.
Ps 

2.825
1  β2
β4

1.5082 β 0.08956
m 12
2ρ1
9.48
See Incompressible Single Phase Flow on Page 263 for a definition of the
symbols.
9 Theoretical Basis
173
Vertical Separators
The Pressure change across the separator comprises the following
components:
Expansion of the multiphase inlet from the inlet diameter, d1, to the body
diameter dbody.
Contraction of vapor phase outlet from the body diameter, dbody, to the outlet
diameter, d2
Friction losses are ignored.
Fig 9.6
Horizontal Separators
The Pressure change across the separator comprises the following
components calculated using the methods described in Incompressible Single
Phase Flow on Page 263:
Expansion of the multiphase inlet from the inlet diameter, d1, to the vapor
space characterized by equivalent diameter of the vapor area.
Contraction of vapor phase outlet from the vapor space characterized by the
equivalent diameter of the vapor area, to the outlet diameter, d2
Friction losses are ignored.
Fig 9.7
174
9 Theoretical Basis
Vapor-Liquid Equilibrium
Compressible Gas
The PVT relationship is expressed as:
PV  ZRT
9.49
where :
P  Pressure
V  Volume
Z  Compressibility factor
R  Gas constant
T  Temperature
The compressibility factor Z is a function of reduced temperature and
pressure. The overall critical temperature and pressure are determined using
applicable mixing rules.
Vapor Pressure
The following equations are used for estimating the vapor pressure, given the
component critical properties3:

Inp * r  Inp * r
   ωInp  
0
*
1
r
9.50
Inp    5.92714  6.09648
 1.28862InT
T
*
0
r
r
 0.169347Tr6
r
9 Theoretical Basis
175
9.51
Inp    15.2518  16.T6875  13.4721InT
*
1
r
r
 0.43577Tr6
r
9.52
where :
pr*  Reduced vapour pressure ( p * / pc )
p *  Vapour pressure ( psi abs )
pc  Critical pressure ( psi abs )
ω  Acentric factor
Tr  Reduced temperature (T / Tc )
T  Temperature ( oR)
Tc  Critical temperature ( oR)
This equation is restricted to reduced temperatures greater than 0.30, and
should not be used below the freezing point. Its use was intended for
hydrocarbons, but it generally works well with water.
Soave Redlich Kwong
It was noted by Wilson (1965, 1966) that the main drawback of the RedlichKwong equation of state was its inability of accurately reproducing the vapor
pressures of pure component constituents of a given mixture. He proposed a
modification to the RK equation of state using the acentricity as a correlating
parameter, but this approach was widely ignored until 1972, when Soave
(1972) proposed a modification of the SRK equation of this form:
P
RT
a T , Tc , ω

V  b V V  b 
9.53
The a term was fitted in such a way as to reproduce the vapor pressure of
hydrocarbons using the acentric factor as a correlating parameter. This led to
the following development:
P
RT
ac α

V  b V V  b 
9.54
ac   a
176
R 2Tc2
 a the same as RK 
Pc
9 Theoretical Basis
9.55

α  1  S 1  Tr0.5

9.56
S  0.480  1.574ω - 0.176ω 2
9.57
The reduced form is:
Pr 
3Tr
3.8473α

Vr  0.2559 Vr Vr  0.2599
9.58
The SRK equation of state can represent with good accuracy the behavior of
hydrocarbon systems for separation operations, and since it is readily
converted into computer code, its usage has been extensive in the last twenty
years. Other derived thermodynamic properties, like enthalpies and entropies,
are reasonably accurate for engineering work, and the SRK equation enjoys
wide acceptance in the engineering community today.
Peng Robinson
Peng and Robinson (1976) noted that although the SRK was an improvement
over the RK equation for VLE calculations, the densities for the liquid phase
were still in considerable disagreement with experimental values due to a
universal critical compressibility factor of 0.3333, which was still too high.
They proposed a modification to the RK equation which reduced the critical
compressibility to about 0.307, and which would also represent the VLE of
natural gas systems accurately. This improved equation is represented by:
P
RT
ac α

V  b V V  b   bV  b 
9.59
R 2Tc2
ac  0.45724
Pc
9.60
b  0.07780
RTc
Pc
9.61
They used the same functional dependency for the term as Soave:
9 Theoretical Basis
177

α  1  S 1  Tr0.5

9.62
S  0.37464  1.5422 ω - 0.26992ω 2
9.63
Pr 
3.2573Tr
4.8514α
 2
Vr  0.2534 Vr  0.5068Vr  0.0642
9.64
The accuracy of the SRK and PR equations of state are roughly the same
(except for density calculations).
Physical Properties
Vapor Density
Vapor density is calculated using the compressibility factor calculated from
the Berthalot equation5. This equation correlates the compressibility factor to
the pseudo reduced pressure and pseudo reduced temperature.

P
Z  1.0  0.0703 r
Tr


6.0 
1.0  2 
Tr 

9.65
ρ
PM
ZRT
9.66
Liquid Density
Saturated liquid volumes are obtained using a corresponding states equation
developed by R. W. Hankinson and G. H. Thompson14 which explicitly relates
the liquid volume of a pure component to its reduced temperature and a
second parameter termed the characteristic volume. This method has been
adopted as an API standard. The pure compound parameters needed in the
corresponding states liquid density (COSTALD) calculations are taken from
the original tables published by Hankinson and Thompson, and the API data
book for components contained in Aspen Flare System Analyzer's library. The
parameters for hypothetical components are based on the API gravity and the
generalized Lu equation. Although the COSTALD method was developed for
saturated liquid densities, it can be applied to sub-cooled liquid densities, i.e.,
178
9 Theoretical Basis
at pressures greater than the vapor pressure, using the Chueh and Prausnitz
correction factor for compressed fluids. The COSTALD model was modified to
improve its accuracy to predict the density for all systems whose pseudoreduced temperature is below 1.0. Above this temperature, the equation of
state compressibility factor is used to calculate the liquid density.
Vapor Viscosity
Vapor viscosity is calculated from the Golubev3 method. These equations
correlate the vapor viscosity to molecular weight, temperature and the
pseudo critical properties.
Tr > 1.0
μ
3.5M 0.5 Pc0.667Tr( 0.71 0.29 / Tr )
10000.0Tc0.167
9.67
Tr ≤ 1.0
μ
3.5 M 0.5 Pc0.667Tr( 0.965)
10000.0Tc0.167
9.68
Liquid Viscosity
Aspen Flare System Analyzer will automatically select the model best suited
for predicting the phase viscosities of the system under study. The model
selected will be from one of the three available in Aspen Flare System
Analyzer: a modification of the NBS method (Ely and Hanley), Twu's model,
and a modification of the Letsou-Stiel correlation. Aspen Flare System
Analyzer will select the appropriate model using the following criteria:
Chemical System
Liquid Phase Methodology
Lt Hydrocarbons (NBP < 155 F)
Mod Ely & Hanley
Hvy Hydrocarbons (NBP > 155 F)
Twu
Non-Ideal Chemicals
Mod Letsou-Stiel
All the models are based on corresponding states principles and have been
modified for more reliable application. These models were selected since they
were found from internal validation to yield the most reliable results for the
chemical systems shown. Viscosity predictions for light hydrocarbon liquid
phases and vapor phases were found to be handled more reliably by an inhouse modification of the original Ely and Hanley model, heavier hydrocarbon
liquids were more effectively handled by Twu's model, and chemical systems
were more accurately handled by an in-house modification of the original
Letsou-Stiel model.
9 Theoretical Basis
179
A complete description of the original corresponding states (NBS) model used
for viscosity predictions is presented by Ely and Hanley in their NBS
publication16. The original model has been modified to eliminate the iterative
procedure for calculating the system shape factors. The generalized LeechLeland shape factor models have been replaced by component specific
models. Aspen Flare System Analyzer constructs a PVT map for each
component and regresses the shape factor constants such that the PVT map
can be reproduced using the reference fluid.
Note: The PVT map is constructed using the COSTALD for the liquid region.
The shape factor constants for all the library components have already been
regressed and are stored with the pure component properties.
Pseudo component shape factor constants are regressed when the physical
properties are supplied. Kinematic or dynamic viscosity versus temperature
curves may be supplied to replace Aspen Flare System Analyzer's internal
pure component viscosity correlations. Aspen Flare System Analyzer uses the
viscosity curves, whether supplied or internally calculated, with the physical
properties to generate a PVT map and regress the shape factor constants.
Pure component data is not required, but if it is available it will increase the
accuracy of the calculation.
The general model employs methane as a reference fluid and is applicable to
the entire range of non-polar fluid mixtures in the hydrocarbon industry.
Accuracy for highly aromatic or naphthenic oil will be increased by supplying
viscosity curves when available, since the pure component property
generators were developed for average crude oils. The model also handles
water and acid gases as well as quantum gases.
Although the modified NBS model handles these systems very well, the Twu
method was found to do a better job of predicting the viscosities of heavier
hydrocarbon liquids. The Twu model18 is also based on corresponding states
principles, but has implemented a viscosity correlation for n-alkanes as its
reference fluid instead of methane. A complete description of this model is
given in the paper18 titled "Internally Consistent Correlation for Predicting
Liquid Viscosities of Petroleum Fractions".
For chemical systems the modified NBS model of Ely and Hanley is used for
predicting vapor phase viscosities, whereas a modified form of the LetsouStiel model15 is used for predicting the liquid viscosities. This method is also
based on corresponding states principles and was found to perform
satisfactorily for the components tested.
The parameters supplied for all Aspen Flare System Analyzer pure library
components have been fit to match existing viscosity data over a broad
operating range. Although this will yield good viscosity predictions as an
average over the entire range, improved accuracy over a more narrow
operating range can be achieved by supplying viscosity curves for any given
component. This may be achieved either by modifying an existing library
component through Aspen Flare System Analyzer's component librarian or by
entering the desired component as a hypothetical and supplying its viscosity
curve.
180
9 Theoretical Basis
Liquid Phase Mixing Rules for Viscosity
The estimates of the apparent liquid phase viscosity of immiscible
Hydrocarbon Liquid - Aqueous mixtures are calculated using the following
"mixing rules":
If the volume fraction of the hydrocarbon phase is greater than or equal to
0.33, the following equation is used19:
μ eff  μ oil e3.61voil 
9.69
where :
μ eff  Apparent viscosity
μ oil  Viscosity of Hydrocarbon phase
voil  Volume fraction Hydrocarbon phase
If the volume fraction of the hydrocarbon phase is less than 0.33, the
following equation is used20:

 μ oil  0.4μ H 2O 
μ H O
μ eff  1  2.5voil 

 2
μ

μ

H 2O
 oil

9.70
where :
μ eff  Apparent viscosity
μ oil  Viscosity of Hydrocarbon phase
μ H 2O  Viscosity of Aqueous phase
voil  Volume fraction Hydrocarbon phase
The remaining properties of the pseudo phase are calculated as follows:
mweff   xi mwi
(molecular weight)
9.71
ρ eff  1 /   xi / pi  (mixture density)
9.72
Cpeff   xi Cpi
9 Theoretical Basis
(misture specific heat )
181
9.73
Thermal Conductivity
As in viscosity predictions, a number of different models and component
specific correlations are implemented for prediction of liquid and vapor phase
thermal conductivities. The text by Reid, Prausnitz and Polings15 was used as
a general guideline in determining which model was best suited for each class
of components. For hydrocarbon systems the corresponding states method
proposed by Ely and Hanley16 is generally used. The method requires
molecular weight, acentric factor and ideal heat capacity for each component.
These parameters are tabulated for all library components and may either be
input or calculated for hypothetical components. It is recommended that all of
these parameters be supplied for non-hydrocarbon hypotheticals to ensure
reliable thermal conductivity coefficients and enthalpy departures.
The modifications to the method are identical to those for the viscosity
calculations. Shape factors calculated in the viscosity routines are used
directly in the thermal conductivity equations. The accuracy of the method
will depend on the consistency of the original PVT map.
The Sato-Reidel method15 is used for liquid phase thermal conductivity
predictions of glycols and acids, the Latini et al. Method15 is used for esters,
alcohols and light hydrocarbons in the range of C3 - C7, and the Missenard
and Reidel method15 is used for the remaining components.
For vapor phase thermal conductivity predictions, the Misic and Thodos, and
Chung et al. 15 methods are used. The effect of higher pressure on thermal
conductivities is taken into account by the Chung et al. method.
As in viscosity, the thermal conductivity for two liquid phases is approximated
by using empirical mixing rules for generating a single pseudo liquid phase
property.
Enthalpy
Ideal Gas
The ideal gas enthalpy is calculated from the following equation:
H ideal  Ai  BiT  CiT 2  DiT 3  EiT 4
9.74
where :
H  Ideal enthalpy
T  Temperature
A, B, C , D, E  Ideal gas heat capacity terms
182
9 Theoretical Basis
Lee-Kesler
The Lee-Kesler enthalpy method corrects the ideal gas enthalpy for
temperature and pressure.
H  H ideal  H dep
9.75
s
r
 H dep   H dep 
ω  H dep 

  
  r 

 RTc   RTc  ω  RTc 
 H dep 

 
 RTc 
s



9.76
 H dep 


 RTc 
k

 2b3k   3b4k
k


b


2
Tr   Tt 2
 k

 Tr Z  1.0 
TrVr




 c2k

 3c k
  23
 Tr
2TrVr2




k
  d 2  3E 

5TrVr5



9.77
γ

 k
γ k  Vr2 
k
β  1.0   β  1  2 e 
Vr  



k
ck
E  34 k
2Tr γ
9.78
where :
Tc  Critical temperature
H  Specific enthalpy
ω  Acentric factor
r  Reference fluid
s  Simple fluid
H ideal  Ideal enthalpy
b, c, d , β, γ  Lee  Kesler terms
H dep  Ideal gas departure enthalpy
Equations of State
The Enthalpy and Entropy calculations are performed rigorously using the
following exact thermodynamic relations:
V

H  H ID
1   P 
 Z 1
  P dV
T 

RT
RT    T V

9 Theoretical Basis
183
9.79
V
 1  P 
S  S oID
P
1
 InZ  In o    
  dV
R
P   R  T V V 
9.80
For the Peng Robinson Equation of State, we have:
H  H ID
1
 Z  1  1. 5
RT
2 bRT




da   V  2 0.5  1 b 


a

T
In 

dt   V  2 0.5  1 b 
9.81




S  S oID
P
A  Tda   Z  2 0.5  1 B 
 In Z  B   In o  1.5 
 In 

R
P
2 B  adT   Z  2 0.5  1 B 
9.82
where :
a   xi x j ai a j  1  kij 
N
N
0.5
i 1 j 1
9.83
For the SRK Equation of State:
H  H ID
1
 Z 1
RT
bRT
da  
b

a  T dt  In1  V 
9.84
S  SoID
P A  Tda   B 
 InZ  B   In o  
In1  
R
P
B  adT   Z 
9.85
A and B term definitions are provided below:
Term
184
Peng-Robinson
bi
0.077796
ai
aciαi
RTci
Pci
Soave-Redlich-Kwong
0.08664
RTci
Pci
aciαi
9 Theoretical Basis
Term
Peng-Robinson
aci
0.457235

RTci 2
Pci
1  mi 1  Tri0.5
αi

0.37646  1.54226ωi  0.26992ωi2
mi
Soave-Redlich-Kwong
0.42748

RTci 2
Pci
1  mi 1  Tri0.5

0.48  1.57ωi  0.176ωi2
where :
a   xi x j ai a j  1  kij 
N
N
0.5
i 1 j 1
9.86
and
N
b   xi bi
i 1
9.87
ID  Ideal gas
o
 Reference state
R  Ideal gas constant
H  Enthalpy
S  Entropy
9 Theoretical Basis
185
Noise
The sound pressure level at a given distance from the pipe is calculated from
the following equations. In these equations the noise producing mechanism is
assumed to be solely due to the pressure drop due to friction.
 P  π
Wm  1.36

 L  4
2

 v

9.88
 1013 ηWm L 
  t
SPLr  10 log
2
 4 πr

9.89
where :
SPL  Sound pressure level
r  Distance from pipe
η  Acoustic efficiency
P  Change in pressure
t  Pipe wall transmission loss
v  Average fluid velocity
186
9 Theoretical Basis
Fig 9.8
10 - 3
10 - 4
Aco us tical Efficien cy
1 0-5
10 - 6
10 - 7
10 - 8
pt = 1 0.0
10 - 9
p t = 1.0
10 - 10
p t = 0. 1
10 - 11
0 .0
0.2
0 .4
0 .6
0. 8
1.0
M ach N um b er
The transmission loss due to the pipe wall is calculated from:
 0.5mv 
  36.0
t  17.0
  
9.90
where :
m  Pipe wall mass per unit area
v  Average fluid velocity
The acoustical efficiency is calculated from the equation below.
  Pr exp4.9986* ln M  9.5388
9.91
where
Pr = Ratio of higher absolute Pr over lower absolute Pr between two ends of
the pipe (i.e. if upstream pr.> downstream pr., Pr = upstream
pr./downstream pr. Else if upstream pr.< downstream pr., Pr = downstream
pr./upstream pr.)
M = Mach No.
9 Theoretical Basis
187
188
9 Theoretical Basis
A File Format
Import/Export Details
This section provides further details of the import and export capabilities of
Aspen Flare System Analyzer.
Important! The definition format for Import/Export has changed since Aspen
Flare System Analyzer V7.3. As a result, if you are using Aspen Flare System
Analyzer V7.3 or later, you cannot import files generated from Aspen Flare
System Analyzer V7.2 and earlier versions or export on top of a file that has
been generated using Aspen Flare System Analyzer V7.2 or earlier versions.
Process Descriptions
Import Wizard
The purpose of this section of the documentation is to describe step by step
the operation of the import wizard.
End of Step 1
At this stage the import process verifies that the specified import file exists
and opens it. The import wizard is then configured for the appropriate file
type.
Any errors are reported.
End of Step 2
At this stage the import process opens the specified import definition file or
the default or new import definition file as specified in Preferences as
appropriate. A check is made that the import definition file type matches the
file type specified in step 1. The version of the import definition file is then
checked; data object and data item elements are added to update to the
current Aspen Flare System Analyzer version if required.
The next step is to process the file to build the object selector tree view for
Step 3. Any problems in reading the import definition file are reported.
A File Format
189
Step 3
During this step, the Import Wizard extracts Source tab data and Field
Details for each data item as different data objects are selected. Whenever a
new data object is selected, the data on the Source tab is validated and any
problems are reported.
End of Step 4
The first action taken is to save the import definition file if required,
prompting for the file name to be used. The import process then begins. In
detail, the steps are:
1
Clear current results.
2
Open log file if required.
3
Read components one by one. For each component check to see if it
already exists in the current Aspen Flare System Analyzer case. If not,
add the component to list. For database components, use information
from database; otherwise, use the data values from file.
4
Read binary interaction parameter data.
5
Read data for pipes, connector nodes and source nodes one object type at
a time; updating the progress view as appropriate.
6
As each instance of a particular object type is read, check if it already
exists. If so, use the data read to update it; otherwise, create a new
instance of the appropriate object type.
7
Make connections between pipes and nodes. Processing allows for only
one end of the connection to be read.
8
Read scenario data. Existing scenarios will be updated, and new ones
created if required.
9
Read Solver options.
10 Update automatic calculations to reflect new data values.
11 Refresh all views.
12 Close log file, and then close Import Data File. Any background copy of
Excel will be closed at this point.
13 Close the Import Wizard and finish.
General Data Object Import Procedure
For each object type that is read, the detailed import procedure is as follows:
190
1
Check to see if import of this object type is required. Quit reading this
type of data object if not.
2
Process the data object definition data from the Import Definition File.
Search for and open the specified source object. Quit if any errors are
encountered.
3
Search the source data object for an instance of the appropriate object
type using the defined select criteria if required. For Access imports, this
will be a row in the specified table; for Excel imports, this will be a row or
column range in the specified worksheet where cell offset 1,1 is not blank;
for XML imports, this will be an item element within the specified group
element.
4
Repeat steps 2 and 3 to open any sub section data objects.
A File Format
5
Read data items from source one by one.
6
Update counters for number of instances read and search data source for
next object instance. For an Access imports, this will be the next row; for
Excel imports, the next row or column range; for XML imports, the next
item element. Selection criteria will apply if specified. Quit if the next
instance cannot be found.
7
Repeat steps 5 and 6 until all instances have been read.
Export Process
The purpose of this section of the documentation is to describe step by step
the operation of the export wizard.
End of Step 1
At this stage the export process checks to see if the target export file exists.
If so, it opens the file; otherwise, a new file with the defined name is created.
The Export Wizard is then configured for the appropriate file type.
Any errors are reported.
End of Step 2
At this stage, the export process opens the specified export definition file or
the default or new export definition file specified in Preferences as
appropriate. A check is made that the export definition file type matches the
file type specified in step 1. The version of the export definition file is then
checked and data object and data item elements are added to update it to the
current Aspen Flare System Analyzer version if required.
The next step is to process the file to build the object selector tree view for
Step 3. Any problems in reading the export definition file are reported.
Step 3
During this step, the Export Wizard extracts Target tab data and Field
Details for each data item as different data objects are selected. Whenever a
new data object is selected, the data on the Target tab is validated and any
problems are reported.
End of Step 4
The first action taken is to save the export definition file if required,
prompting for the file name to be used. The export process then begins. In
detail the steps are:
A File Format
1
Clear existing data from export file if requested.
2
Write components data.
3
Write binary interaction parameter data.
4
Write pipe data.
5
Write connector node and source node data, working through each type of
node in turn.
6
Write scenario data for scenarios that are selected for calculation.
191
7
Write results data for scenarios that are selected for calculation.
8
Write solver options.
9
Save export file. Any background copy of Excel will be closed at this point.
10 Close the Export Wizard.
General Data Object Export Procedure
For each object type that is written, the detailed export procedure is as
follows:
1
Check that export of this data object type is required. Quit if not.
2
Create target data object using information from export definition file. For
Access export, this will create a table with the correct fields; for Excel
export, a worksheet with the correct name; for XML export, a group tag
with the correct name. Quit if any errors are encountered.
3
Create target data objects as required for any data subsections.
4
For each instance of the data object to be written, search the output file to
see if this instance already exists. If so, select this to be overwritten;
otherwise, create a new instance for the data object in the output file. For
Access export, this will be a new row in that target table; for Excel export,
the next row or column range where cell offset 1,1 is blank; for XML
export, a new item element. Quit if the new target instance cannot be
found.
5
Write the values to the target object instance.
6
Update counters for number of items read and mark target instance as
complete.
7
Repeat steps 4 to 6 until each instance of this data object has been
written.
Definition File Formats
The import and export definition files are XML formatted data files that
describe how the various Aspen Flare System Analyzer data objects and their
corresponding data items should be read from or written to the supported
external file formats. This section of the documentation describes the layout
of these files.
Import File Formats
File Header
The top level element of an import definition file must have the tag name
FlarenetImport and contain the following attributes:
192
Attribute
Description
LastModified
This is a date string that indicates the date that the file was last
updated.
FlarenetVersion
This indicates the version of Aspen Flare System Analyzer that the
file is applicable to.
FileType
This indicates the type of external file import that is described in
this definition file. Valid values are Access, Excel or XML.
A File Format
Data Object Elements
The child elements of the FlarenetImport tag define the various data objects
that may be imported by Aspen Flare System Analyzer. These parent data
object elements may contain child data object elements that describe data
subsections which may be imported from a different location to the parent
data object. For example, a pipe data object has a data subsection defined for
the PFD layout information.
A data object element has the following attributes:
Attribute
Description
ObjectName
This defines the source of the data object in the external file. Its usage
depends on the type of external file as follows:

Access – The entry defines a database table.

Excel – The entry defines a worksheet.

XML – The entry defines the tag name of a group element.
Import
This indicates whether this object type is to be imported. Valid values
are Yes or No.
Contained
This indicates whether the data for this object is contained in the same
external data source as the parent object. Valid values are Yes or No.
This setting is always No for a parent data object.
DataBy
This entry appears in Excel import definition files only. It defines how
the data for this object is organized. Valid values are Row, Column or
Sheet.
StartAt
This entry appears in Excel import definition files only. When DataBy is
set to Row or Column, it defines the starting row or column for the
data. When DataBy is set to Sheet, it defines the tag by which
worksheets of the requisite layout can be identified.
PerItem
This entry appears in Excel import definition files only. It defines the
number of rows or columns occupied by a single instance of a data
object, including any spacing, when DataBy is set to Row or Column.
ItemTag
This entry appears in XML import definition files only. It defines the
element tag name used to identify each instance of a data object within
the group tag name defined in the ObjectName attribute.
A list of valid Data Object elements names is given in Data Objects List.
Data Item Elements
Each data object element contains data item elements that define the location
of the individual data item in the external data source. A data item element
contains the following attributes:
A File Format
Attribute
Description
Import
This indicates whether the item is to be imported. Valid values are Yes
or No.
193
Attribute
Description
Offset
This defines the location of the data value in the external file. Its usage
depends on the type of external file, but data substitution codes can be
defined for the offset in all cases – see Data Substitution Codes.

Access – The entry defines a field within the database table for
the object.

Excel – The entry defines a cell within the worksheet for the
object. The cell is defined either by a single row or column offset
or by a row, column offset.

XML – The entry defines the tag name of an element within the
item tag element for the object.
A list of the data item elements that are recognized for each data object is
given in Data Items List.
Export File Formats
File Header
The top level element of an export definition file must have the tag name
FlarenetExport and contain the following attributes:
Attribute
Description
LastModified
This is a date string that indicates the date that the file was last
updated.
FlarenetVersion
This indicates the version of Aspen Flare System Analyzer that the
file is applicable to.
FileType
This indicates the type of external file export that is described in this
definition file. Valid values are Access, Excel or XML.
Data Object Elements
The child elements of the FlarenetExport tag define the various data objects
that may be exported by Aspen Flare System Analyzer. These parent data
object elements may contain child data object elements that describe data
subsections which may be exported to a different location to the parent data
object.
A data object element has the following attributes:
194
Attribute
Description
ObjectName
This defines the name of the data object that will be created and written
to in the external file. Its usage depends on the type of external file as
follows:

Access – The entry defines a database table.

Excel – The entry defines a worksheet.

XML – The entry defines the tag name of a group element.
Export
This indicates whether this object type is to be exported. Valid values
are Yes or No.
Contained
This indicates whether the data for this object is to be written to the
same external data source as the parent object. Valid values are Yes or
No. This setting is always No for a parent data object.
A File Format
Attribute
Description
DataBy
This entry appears in Excel export definition files only. It defines how
the data for this object is organized. Valid values are Row, Column or
Sheet.
StartAt
This entry appears in Excel export definition files only. When DataBy is
set to Row or Column, it defines the starting row or column for the
data. When DataBy is set to Sheet, it defines the name of the
worksheet that will be copied to create a worksheet for each instance of
the data object. This name must begin with a “%” character.
PerItem
This entry appears in Excel export definition files only. It defines the
number of rows or columns occupied by a single instance of a data
object, including any spacing, when DataBy is set to Row or Column.
ItemTag
This entry appears in XML export definition files only. It defines the
element tag name used to identify each instance of a data object within
the group tag name defined in the ObjectName attribute.
A list of valid Data Object elements names is given in Data Objects List.
Data Item Elements
Each data object element contains data item elements that define how an
individual data item is to be written to the external data source. A data item
element contains the following attributes:
Attribute
Description
Export
This indicates whether the item is to be exported. Valid values are Yes
or No.
Offset
This defines the location where the data value will be written in the
external file. Its usage depends on the type of external file, but data
substitution codes can be defined for the offset in all cases – see Data
Substitution Codes.

Access – The entry defines a field within the database table for
the object.

Excel – The entry defines a cell within the worksheet for the
object. The cell is defined either by a single row or column offset
or by a row, column offset.

XML – The entry defines the tag name of an element within the
item tag element for the object.
Type
This appears in Access export definition files only. It defines the data
type of the field to be created for this item. Valid values are Text for
text strings, Long for integer values, Double for floating point values.
Length
This appears in Access export definition files only. It defines the length of
the field to be created. For fields of type Text, it defines the length of
the text string in characters; for fields of types Long and Double, it is
set to 0 and will be ignored though it must be present.
A list of the data item elements that are recognized for each data object is
given in Data Items List.
Data Substitution Codes
As indicated in the above data substitution codes may be defined in the Offset
attribute for item import and export data items. The details of these codes are
as follows:
A File Format
195
Offset Codes
The following codes are recognized and processed in the Offset attribute in
both import and export definition files.
“%ObjectName”
where ObjectName is the name of a data object element, will be replaced
by a value that iterates as successive instances of that type of object are
read or written for this instance of the parent data object. It is used to
provide a value that iterates through repeated data items, e.g. component
data or pipe fitting data. ObjectName may refer to any data object
element that is a parent of the data item. The code is usually used in
conjunction with a + symbol to add the iteration value to some constant
value.
In an Access or XML import or export definition file, the + symbol means
that the iteration value is concatenated with the constant value. E.g.
Frac+%Composition will be expanded to Frac1, Frac2 etc.
In an Excel import or export definition file, *, -, and / symbols as well as
the + symbol are recognized to combine the iteration value with a
constant value to calculate a cell address. E.g. 2,2+%Composition will be
expanded to the cell references 2,3 then 2,4 etc. See the CurveMassFlow
data item in the TipCurveData data object in the definition file
DefExcel.fni for a more complicated example.
“#ObjectName”
where ObjectName is the name of a data object element, will be replaced
by the total number of instances of that type of data object that have
been read. ObjectName may refer to any data object element that is a
child of the current data object element. The value returned is usually
combined with some constant value through a + or other symbols as for
the “%ObjectName” code.
“?Composition”
is a special code that is used exactly as it stands. “?Composition” will be
replaced by each component name or offset in turn as successive
component composition data items are read or written. It is generally
used in conjunction with a + symbol to each component name or offset to
some constant value.
In an Access or XML import or export definition file, ?Composition will
return component names in turn from the master component list. e.g.
Frac+?Composition will be evaluated as FracMethane, FracEthane etc.
In an Excel import or export definition, ?Composition will return the index
number of a component in the master component list to allow it to be
used to calculate a cell offset.
In both cases, the master component list is the union of the components
in the current Aspen Flare System Analyzer case and the import or export
definition files. Essentially this code allows unambiguous specification of a
component identity when merging of the component lists between a Aspen
Flare System Analyzer case and an import or export definition file.
196
A File Format
Recognized Objects and Items
Data Objects List
Data object elements for the following data objects and sub-sections are
recognized in import and export definition files.
Element Tag
Sub Section Data
Object Elements
Description
Components
None
Component data
BIPs
None
Binary interaction parameters
Connectors
PFDLayout
Connector nodes
ControlValves
PFDLayout
Control valve source nodes
Composition
SourceData
FlowBleeds
PFDLayout
Flow bleed nodes
Composition
Horizontal separator nodes
PFDLayout
OrificePlates
PFDLayout
Orifice plate nodes
Fitting
None
Fitting data for pipes
Pipes
PFDLayout
Pipes
ReliefValves
PFDLayout
Tees
PFDLayout
Tee nodes
FlareTips
PFDLayout
Flare tip nodes
Fitting
Relief valve source nodes
SourceData
Curves
Curves
Points
Tip pressure drop curves
Points
None
Data points in tip pressure drop curve
VerticalSeparators
PFDLayout
Vertical separator nodes
Solvers
None
Solver options
Scenarios
SourceData
Scenario data
Composition
None
Component composition data
SourceData
Composition
Scenario specific source data
PFDLayout
None
PFD layout information
Results
Phase
Summary results data for each pipe.
Export definition files only.
Phase
CompResults
Properties for each phase at each end of
each pipe. Export definition files only.
CompResults
None
Composition results for each pipe. Export
definition files only.
Data Items List
The data items that can be read for each data object are as follows:
A File Format
197
Components
Attribute
Description
Hypothetical
The hypothetical components
Name
The component name
Id
The component ID number
Type
The component type
Formula
The component formula
MolWt
The component molecular weight
NBP
The component normal boiling point (K)
StdDensity
The component standard density (kg/m3)
WatsonK
The component Watson K value
Pc
The component critical pressure (bar a)
Tc
The component critical temperature (K)
Vc
The component critical volume (m3/kgmole)
Vchar
The component characteristic volume (m3/kgmole)
Omega
The component acentric factor
OmegaSRK
The component SRK acentric factor
Ha
The enthalpy A coefficient (kJ/kgmole)
Hb
The enthalpy B coefficient (kJ/kgmole/K)
Hc
The enthalpy C coefficient (kJ/kgmole/K2)
Hd
He
Hf
S
The entropy coefficient
ViscA
The viscosity A parameter
ViscB
The viscosity B parameter
HeatOFCombustion
The heat of combustion
NBPValue
The value of normal boiling point
PcValue
The value of critical pressure
TcValue
The value of critical temperature
BIPs
Attribute
Description
PropPkg
The code for the property package:
Comp1
198

0 – Vapor pressure

1 – Peng Robinson

2 – Soave Redlich Kwong

3 – Compressible Gas
The name of the first component
Comp2
The name of the second component
Kij12
Value of interaction parameter for comp1 / comp2
Kij21
Value of interaction parameter for comp2 / comp1
A File Format
Connectors
Attribute
Description
FittingLossMethod
Code for the fitting loss method: 0 = ignored, 1 =
calculated
IsothermalDPOption
Code for enabling isothermal pressure drop
calculations: 0 = No, 1 = Yes
TwoPhaseCorrection
Code for two phase correction option: 0 = No, 1 = Yes
SwageMethod
Code for size change calculation method: 0 =
Compressible, 1 = Incompressible, 2 = Transition
CompressibleTransition
DP percent of inlet pressure for transition (%)
Length
Length of the swage (mm)
Angle
The internal angle of the swage (radians)
ChokeMethod
Choke flow check
MaxConnectionCount
Maximum possible connection count
DescribeCalculations
Describe calculations
Name
The connector name
Location
The location text
Ignore
The ignored flag: 0 = not ignored, 1=ignored
UpstreamConnection
The name of the upstream pipe
UpstreamConnectionAt
Code for the upstream pipe connection point: 0 =
upstream end, 1 = downstream end
DownstreamConnnection
The name of the downstream pipe
DownstreamConnnectionAt
Code for the downstream pipe connection point: 0 =
ConnectedCount
Connection count
ControlValves
A File Format
Attribute
Description
MaxConnectionCount
Ignore
Ignore flag
KMultiply
Fittings loss Ft factor for inlet pipe
KOffset
Fittings loss offset for inlet pipe
FlangeDiameter
Internal diameter of flange (mm)
ElevationChange
The elevation change of the inlet piping (m)
Length
The length of the inlet piping (m)
InternalDiameter
The inlet pipe diameter (mm)
Schedule
The inlet pipe schedule
NominalDiameter
The inlet pipe nominal diameter
Roughness
The inlet pipe roughness (mm)
Material
The code for the inlet pipe material: 0 = Carbon
Steel, 1 = Stainless steel
Thickness
Code for the thickness of the pipe wall
UsePipeClass
Code for enabling pipe class usage: 0 = No, 1 =
Yes
Name
The control valve name
199
Attribute
Description
Location
The location text
UpstreamConnnection
UpstreamConnnectionAt
ConnectedCount
Connection count
FlowBleeds
Attribute
Description
OfftakeMultiplier
Flow bleed multiplier
OfftakeOffset
Bleed flow offset (kg/h)
OfftakeMinimum
Minimum bleed flow (kg/h)
OfftakeMaximum
Maximum bleed flow (kg/h)
PressureDrop
Pressure drop over bleed (bar)
MaxConnectionCount
Name
The flow bleed name
Location
The location text
Ignore
UpstreamConnection
Code for the upstream pipe connection point
0 = upstream end, 1 = downstream end
Code for the downstream pipe connection point
0 = upstream end, 1 = downstream end
ConnectedCount
Connection count
200
Attribute
Description
LiquidLevel
The liquid level (mm)
Diameter
The vessel diameter (mm)
FittingLossMethod
Code for fittings loss calculation: 0 = Ignored, 1 =
Calculated
IsothermalPressureDrop
TwoPhaseCorrection
SwageMethod
BodyDimension
Code for body area usage: 0 = Full body area, 1 =
Partial body area on flow
ChokeMethod
Choke flow check
CannotTear
Cannot tear
DesignLength
Design length
Ddrop
Ddrop
A File Format
Attribute
Description
DrainVol
Drain volume
Holduptime
Holdup time
Vsettling
V settling
IsTear
Is tear
PresBody
Body pressure
TempBody
Body temperature
VelBody
Body velocity
DenBody
Body density
MaxConnectionCount
Name
The horizontal separator name
Ignore
Location
The location text
UpstreamConnection
BranchstreamConnection
The name of the branch stream pipe
BranchstreamConnectionAt
Code for the branch stream pipe connection point: 0 =
DownstreamConnection
DownstreamConnectionAt
ConnectedCount
Connection count
OrificePlates
A File Format
Attribute
Description
FittingLossMethod
Code for pressure loss method: 0 = Ignored, 1 = Thin
Plate, 2 = Contraction/Expansion
Code for enabling isothermal pressure drop calculations:
0 = No, 1 = Yes
TwoPhaseCorrection
SwageMethod
Compressible, 1 = Incompressible, 2 = Transition=
DownstreamDiameterRatio
Ratio of orifice to downstream diameter
UpstreamDiameterRatio
Ratio of orifice to upstream diameter
Diameter
Diameter of orifice (mm)
ChokeMethod
Choke flow check
MaxConnectionCount
Name
The orifice plate name
Location
The location text
Ignore
UpstreamConnection
201
Attribute
Description
The code for the upstream pipe connection point: 0 =
The code for the downstream pipe connection point: 0 =
ConnectedCount
Connection count
Pipes
202
Attribute
Description
LimitReached
Reached limit or not
TailPipe
Code to identify tailpipe: 0 = No, 1 = Yes
Sizeable
Code for indicating sizeable pipe: 0 = No, 1 = Yes
UsePipeClass
Code for pipe class usage: 0 = No, 1 = Yes
WallThickness
Pipe wall thickness (mm)
InternalDiameter
Pipe internal diameter (mm)
Schedule
Pipe schedule
NominalDiameter
Pipe nominal diameter
ThermalConductivity
Pipe material thermal conductivity (W/m/C)
Roughness
Pipe absolute roughness (mm)
Material
Code for pipe material: 0 = Carbon steel, 1 =
Stainless steel
ElevationChange
Pipe elevation change (m)
Length
Pipe length (m)
FittingsLossMultiply
Fittings loss Ft factor
FittingsLossOffset
Fittings loss offset
LengthMultiplier
Multiplier for pipe length
MultipleElementCalculation
Code for the multiple element heat transfer
calculation: 0 = No, 1 = Yes
Emissivity
The material fractional emissivity
ExternalRadiativeHTC
Code for including radiative heat transfer: 0 = No, 1
= Yes
HeatTransferEnabled
Code to enable heat transfer calculations: 0 = No, 1
= Yes
WindVelocity
Wind speed (m/s)
Temperature
Temperature outside pipe (C)
InsulationThermalConductivity
Insulation thermal conductivity (W/m/C)
Thickness
Insulation thickness (mm)
InsulationName
Insulation description
Duty
Duty (kJ/h)
Temperature leaving pipe (C)
DampingFactor
Damping factor
VLEMethod
Code for VLE method: 0 = Default, 1 = Compressible
Gas, 2 = Peng Robinson, 3 = Soave Redlich Kwong,
4 = Vapor Pressure
A File Format
Attribute
Description
StaticHeadContribution
Code for the static head contribution: 0 = Include, 1
= Ignore Downhill Recovery, 2 = Ignore
FrictionFactorMethod
Code for friction factor method: 0 = Default, 1 =
Round, 2 = Chen
Elements
Number of elements for pipe calculation
VerticalPipe
Code for DP method for vertical pipes: 0 = Default, 1
= Isothermal gas, 2 – Adiabatic gas, 3 =
Beggs&Brill, 4 = Dukler, 5 = Orkisewski
InclinedPipeMethod
Code for DP method for inclined pipes: 0 = Default,
1 = Isothermal gas, 2 – Adiabatic gas, 3 =
Beggs&Brill, 4 = Dukler
HorizontalPipeMethod
Code for DP method for horizontal pipes: 0 =
Default, 1 = Isothermal gas, 2 – Adiabatic gas, 3 =
Beggs&Brill, 4 = Dukler
ExternalMedium
Code for the external medium: 0 = Air, 1 = Sea
Water
RoughnessForFitting
Roughness for fitting
Klocked
K locked
Kusing
K using
CalcStatus
Calculation status
FittingCount
Number of fittings linked to this pipe
PhysicalLength
Physical length
MaxConnectionCount
Name
Name
Ignore
Location
The location text
UpstreamConnection
The name of the upstream node
Code for the upstream node connection point: 0,1,2
depending on upstream node
The name of the downstream node
Code for the downstream pipe connection point:
0,1,2 depending on downstream node
ConnectedCount
Connection count
Fitting
Attribute
Description
ItemName
The name of the fitting
ID
Description of the fitting
KOffset
Fitting loss constant
KMultiplier
Fitting loss Ft factor
ReliefValves
A File Format
Attribute
Description
MAWP
Maximum allowable working pressure (bar a)
203
Attribute
Description
MechPres
Mechanical pressure limit (bar a)
ValveType
Type code for valve: 0 = Balanced, 1 =
Conventional
OrificeType
Standard type code for orifice
ValveArea
Area of each valve orifice (mm2)
ValveCount
Number of valves
IsenTropicFlash
Isentropic flash
MaxConnectionCount
Ignore
Ignore flag
KMultiply
Fittings loss Ft factor for inlet pipe
KOffset
Fittings loss offset for inlet pipe
FlangeDiameter
Internal diameter of flange (mm)
ElevationChange
The elevation change of the inlet piping (m)
Length
The length of the inlet piping (m)
InternalDiameter
The inlet pipe diameter (mm)
Schedule
The inlet pipe schedule
NominalDiameter
The inlet pipe nominal diameter
Roughness
The inlet pipe roughness (mm)
Material
Code for the inlet pipe material: 0 = Carbon Steel,
1 = Stainless steel
Thickness
Thickness
UsePipeClass
Code for enabling pipe class usage: 0 = No, 1 =
Yes
Name
The relief valve name
Location
The location text
UpstreamConnnection
UpstreamConnnectionAt
ConnectedCount
Connection count
Tees
204
Attribute
Description
Body
Code for body type: 0 = Run, 1 = Tail, 2 = Branch, 3
= Auto
Theta
Code for branch angle: 0 = 30 deg, 1 = 45 deg, 2 =
60 deg, 3 = 90 deg
ThetaAsReal
Theta as real
FittingLossMethod
Simple, 2 = Miller
MillerChartExtrapolation
Code for Miller chart extrapolation: 0 = None, 1 =
Miller Ratio Squared, 2 = Gardel
ConnectorIfIncomplete
Code to use connector calculation: 0 = No, 1 = Yes
A File Format
Attribute
Description
TwoPhaseCorrection
Code for two phase correction option: 0 = No, 1 =
Yes
SwageMethod
BodyDimension
Code for body area usage: 0 = Full body area, 1 =
Partial body area on flow
ChokeMethod
Choke flow check
Orientation
Orientation
Separate
Separate
CannotTear
Cannot tear
MaxConnectionCount
Name
The tee name
Location
The location text
Ignore
UpstreamConnection
BranchstreamConnection
The name of the branch stream pipe
BranchstreamConnectionAt
Code for the branch stream pipe connection point: 0
= upstream end, 1 = downstream end
ConnectedCount
Connection count
FlareTips
A File Format
Attribute
Description
Diameter
Diameter of flare (mm)
Method
Method
TwoPhaseCorrection
0 = No, 1 = Yes
FittingLossCoefficient
Fittings loss coefficient
FittingLossCoefficientBasis
Code for fittings loss basis: 0 = Total pressure, 1 =
static pressure
UseCurves
Code for curve usage: 0 = No, 1 = Yes
NumCurves
Number of pressure drop curves
FlowExtrapolation
Flow extrapolation
MolWtExtrapolation
Molecular weight extrapolation
PressureCorrection
Pressure correction
RefTemp
Reference temperature for curve data (C)
Sizeable
Code for indicating sizeable pipe
205
Attribute
Description
UsePipeClass
Code for enabling Pipe Class usage
WallThickness
Wall thickness
InternalDiameter
Internal diameter
Schedule
Pipe schedule
NominalDiameter
Pipe nominal diameter
ThermalConductivity
Pipe material thermal conductivity (W/m/C)
Roughness
Pipe roughness
Material
Code for the inlet pipe material
ChokeMethod
Choke flow check
MaxConnectionCount
Name
The flare tip name
Location
The location text
Ignore
UpstreamConnection
ConnectedCount
Connection count
Curves
Attribute
Description
TipName
The name of the top (30 chars)
MolWt
The reference molecular weight for the curve
CurveNumPoints
The number of points in the curve
Points
Attribute
Description
CurveDataPointNo
The number of the curve data point
MolWt
The mole weight of the curve
MassFlow
The mass flow for the curve data point (kg/h)
PresDrop
The pressure drop for the curve data point (bar)
VerticalSeparators
206
Attribute
Description
Diameter
The vessel diameter (mm)
FittingLossMethod
Calculated
0 = No, 1 = Yes
TwoPhaseCorrection
SwageMethod
A File Format
Attribute
Description
ChokeMethod
Choke flow check
DesignDiameter
Design diameter
Ddrop
Ddrop
Vsettling
V settling
PresBody
Body pressure
TempBody
Body temperature
VelBody
Body velocity
DenBody
Body density
MaxConnectionCount
Name
The vertical separator name
Location
The location text
Ignore
UpstreamConnection
ConnectedCount
Connection count
Scenarios
Attribute
Description
Name
The scenario name (30 chars)
OptionVelConstr
Option velocity constraint
Done
Done
HeaderMach
Header mach number limit
HeaderVapVel
Header vapor velocity limit (m/s)
HeaderLiqVel
Header liquid velocity limit (m/s)
HeaderRV2
Header momentum limit (kg/m/s2)
HeaderNoise
Header noise limit (dB)
TailPipeMach
Tailpipe mach number limit
TailPipeVapVel
Tailpipe vapor velocity limit (m/s)
TailPipeLiqVel
Tailpipe liquid velocity limit (m/s)
TailPipeRV2
Tailpipe momentum limit (kg/m/s2)
TailPipeNoise
Tailpipe noise limit (dB)
Pressure
System back pressure (bar a)
CalculateMe
Calculate me
SolverOptions
A File Format
Attribute
Description
AmbientTemperature
External temperature (C)
AtmosphericPressure
Atmospheric pressure (bar a)
207
208
Attribute
Description
CheckChoke
Check for choke flow: 0 = No, 1 = Yes
Choke
Code for choke calculation method: 0 = Simple, 1 =
HEM
HeatTransfer
Enable heat transfer calculations: 0 = No, 1 = Yes
ExternalRadiation
External radiation
Mode
Code for calculation mode: 0 = Rating, 1 = Design, 2
= Debottleneck
RatedFlow
Use rated flow for inlet pipes
RatedFlowNodes
Use rated flow for downstream nodes attached to
tailpipes
RatedFlowTailPipe
Use rated flow for tailpipes: 0 = No, 1 = Yes
WindSpeed
Wind velocity (m/s)
UseKineticEnergy
Include kinetic energy: 0 = No, 1 = Yes
IgnoreSepKineticEnergy
Ignore kinetic energy in separators: 0 = No, 1 - Yes
KineticEnergyBasis
Code for kinetic energy basis: 0 = Inlet Pipe Velocity,
1 = Zero velocity
CalcIgnoredSources
Calculate ignored sources as zero flow: 0 = No, 1 =
Yes
MabpForInactiveValves
Check MABP for inactive sources: 0 = No, 1 = Yes
IgnoreSourceSizeChangeWh
enSizing
Ignore valve flange size change in design calculations:
0 = No, 1 = Yes
MaxmumSystemVelocity
Maximum system velocity
AllScenarios
Code to indicate which scenarios are calculated: 0 =
Current, 1 = All, 2 = Selected
VLE
Code for VLE method: 0 = Compressible gas, 1 =
Peng Robinson, 2 = Soave Redlich Kwong, 3 = Vapor
Pressure
Enthalpy
Code for enthalpy method: 0 = Ideal gas, 1 =
PengRobinson, 2 = Soave Redlich Kwong, 3 = Lee
Kesler
VleSourceOutletTemp
VLE source outlet temperature
EnthalpySourceOutletTemp
Enthalpy source outlet temperature
Horizontal
Code for horizontal pressure drop method: 0 =
Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3
= Dukler
Inclined
Code for inclined pressure drop method: 0 =
= Dukler
Vertical
Code for vertical pressure drop method: 0 =
= Dukler, 4 = Orkisewski
Elements
Number of elements for two phase calculations
FrictionFactor
Code for friction factor method: 0 = Round, 1 = Chen
UsePipeRoughnessForFitting
Use pipe roughness for fitting
RoughnessForFitting
Roughness for fitting
WarnMachForSizing
Warn Mach for sizing
WarnVelocityForSizing
Warn velocity for sizing
WarnRhoV2ForSizing
Warn RhoV2 for sizing
A File Format
A File Format
Attribute
Description
WarnNoiseForSizing
Warn noise for sizing
WarnIceFormForSizing
Warn Ice form for sizing
WarnBPForSizing
Warn BPF for sizing
WarnChokeForSizing
Warn choke flow for sizing
WarnSlugForSizing
Warn slug flow for sizing
WarnTempForSizing
Warn temperature for sizing
WarnPressureBasis
Warn pressure basis
WarnPhysPropFailure
Warn physical properties failure
WarnHeatBalanceFailure
Warn heat balance failure
WarnChokePresFailure
Warn choke pressure failure
WarnPresDropFailure
Warn pressure drop failure
WarnLiqWithVapMethodFail
ure
Warn liquid with vapour only method failure
WarnCorrRangeFailure
Warn correlation out of range failure
WarnInitWhileSizing
Warn initialization while sizing
WarnSizeChangeWhileSizing
Warn size change while sizing
WarnLimitReachedWhileSizi
ng
Warn limit reached while sizing
PresTolProperties
Pressure tolerance in properties loop (%)
PresTolUnitOp
Pressure tolerance for unit operation calculations (%)
PresTolLoop
Pressure tolerance for loop calculations (%)
MassToLoop
Mass balance tolerance in outer loop (%)
IterationsProperties
Number of iterations in inner (properties) loop
IterationsLoop
Number of iterations for loop calculations
DamperProperties
Damping factor for inner (properties) loop
DamperLoop
Damping factor for loop calculations
LoopMethod
Select loop convergence method: 0=Newton Raphson,
1=Broyden, 2=Force Convergent
LoopAnalyser
Select analyzer for looped systems: 0 = Convergent, 1
= Simultaneous
EchoLoops
Are loop calculations echoed: 0 = No, 1 = Yes
KeepBad
Keep bad
UpdateEstimates
Update flow estimates from solution: 0 = No, 1 = Yes
InitalPressure
Initial pressure for property calculations (bar a)
LengthMultiplier
Pipe length multiplication factor
InitPhaseMethodForSizing
Initialization phase method for sizing
UpstreamMinTemp
Upstream minimum temperature
DownstreamMinTemp
Downstream minimum temperature
UpstreamMaxTemp
Upstream maximum temperature
DownstreamMaxTemp
Downstream maximum temperature
InletFlowCheck
Inlet flow check
GaugeInletCheck
Gauge inlet check
IgnoreInlet
Ignore inlet
209
SourceData
Attribute
Description
ScenarioName
The name of the scenario
SourceName
The name of the source
MassFlow
Mass flow of the source (kg/h)
Ignored
PresAllow
Allowable pressure
OutletTemperature
Outlet temperature (C)
InletTemp
Inlet temperature
InletTempSpec
Inlet specified temperature value (C)
InletPressure
Inlet pressure
LockMABP
VLEMethod
Code for VLE method: 0 = Model default, 1 =
Compressible gas, 2 = Peng Robinson, 3 = Soave
Redlich Kwong, 4 = Vapor Pressure
FittingLossMethod
Code for fitting loss calculation: 0 = Ignored, 1 =
Calculated
TwoPhaseCorrection
Code for two phase correction option: 0 = No, 1 =
Yes
SwageMethod
VapourFraction
Vapour fraction
VapourMolWt
Vapour molecular weight
IsentropicEfficiency
210
Auto update of MABP: 0 = No, 1 = Yes
Isentropic efficiency
SizingMethod
Code for PSV sizing method: 0 = API, 1 = HEM
BackPressure
Back pressure
MultiPhaseCd
Multi-phase Cd
LiquidCd
Liquid Cd
Kb
Kb
RuptureDisk
Rupture disk
PresCalc
Static pressure
DenCalc
Calculated density
VelCalc
Velocity
TempCalc
Temperature
ChokeMethod
Choke flow check
Energy
Energy
Enthalpy
Enthalpy
Entropy
Entropy
Quality
Quality
Tempincalc
Calculated inlet temperature
SonicCalc
Calculated sonic
NonRecoverablePresDrop
Piping non-recoverable pressure drop
InletVelocity
Inlet velocity
A File Format
Attribute
Description
InletDensity
Inlet density
StaticPresDrop
Static pressure drop
TotalPresDrop
Total pressure drop
HasProblem
Has problem flag
HeaderVapourFraction
Header vapour fraction
HeaderVapourMolWt
Header vapour molecular weight
HasProblemDp
Constraint violation: pressure drop
HasProblemVel
Constraint violation: velocity
HasProblemMach
Constraint violation: Mach number
HasProblemChoke
Constraint violation: choke
HasProblemRhoV2
Constraint violation: RhoV2
HasProblemPres
Constraint violation: pressure
HasProblemTemp
Constraint violation: temperature
VfCalc
Vf calculation
StagnationEnthalpy
Stagnation enthalpy
StagnationEnthalpyCalc
Calculated stagnation enthalpy
FlowPathCount
Flow path count
FlowPathName
Flow path name
FlowPathType
Flow path type
RatedFlow
Rated flow of the source (kg/h)
Contingency
Code for sizing contingency: 0 = Operating, 1 = Fire
LockRatedFlow
Auto update of rated flow: 0 = No, 1 = Yes
LockReliefPressure
Auto update of relieving pressure: 0 = No, 1 = Yes
CpCvRatio
Cp Cv ratio
Compressibility
Compressibility
InletPresTotalCalc
Total inlet pressure
PresTotalCalc
Total pressure
MachNo
Mach number
RhoV2Calc
Rho V2
MolarFlow
Molar flow
MolWt
Fluid molecular weight
StaticPresDropForSummary
Valve static pressure drop
TotalPresDropForSummary
Valve total pressure drop
Composition
A File Format
Attribute
Description
ScenarioName
SourceName
The name of the source
FluidType
Fluid type
Basis
Code for composition input basis: 0 = MolWt, 1 = Mole
fraction, 2 = Mass fraction
MolWt
Molecular weight
211
PFDLayout
Attribute
Description
ItemName
The name of the PFD item
XPosition
The X coordinate of the item
YPosition
The Y coordinate of the item
LabelXPosition
The X coordinate of the item label
LabelYPosition
The X coordinate of the item label
RotationFlipType
Code for icon rotation: 0 = None, 1 = Rotate 90°, 2 = Rotate
180°, 3 = Rotate 270°, 4 = Flip X, 5 = Rotate 90° + Flip Y, 6 =
Flip Y, 7 = Rotate 90° + Flip X
Results
Attribute
Description
ScenarioName
SegmentName
The name of the pipe segment
MolWt
Molecular weight
MolarFlow
Molar weight
MassFlow
The mass flow (kg/h)
UpstreamTestFlow
Test flow of upstream
DownstreamTestFlow
Test flow of downstream
dp_F
Pressure drop due to friction (bar)
dp_A
Pressure drop due to acceleration (bar)
dp_E
Pressure drop due to elevation change (bar)
dp
Pressure drop
Noise
Noise (dB)
HtcInternal
Internal heat transfer coefficient (W/m2/C)
HtcConvExternal
External heat transfer coefficient (W/m2/C)
HtcOverall
Overall heat transfer coefficient (W/m2/C)
UpstreamVelocityNonRated
Upstream non-rated velocity
DownstreamVelocityNonRated
Downstream non-rated velocity
UpstreamVelocityRated
Upstream rated velocity
DownstreamVelocityRated
212
Downstream rated velocity
UpstreamVelocity
Velocity at upstream end of pipe (m/s)
DownstreamVelocity
Velocity at downstream end of pipe (m/s)
UpstreamSonicVelocity
Upstream sonic velocity
DownstreamSonicVelocity
Downstream sonic velocity
UpstreamPresTotalNonRated
Upstream total non-rated pressure
DownstreamPresTotalNonRated
Downstream total non-rated pressure
UpstreamPresTotalRated
Upstream total rated pressure
DownstreamPresTotalRated
Downstream total rated pressure
UpstreamPresTotal
Upstream total pressure
DownstreamPresTotal
Downstream total pressure
UpstreamPresStatic
Upstream static pressure
DownstreamPresStatic
Downstream static pressure
A File Format
Attribute
UpstreamTemperature
Temperature at upstream end of pipe (C)
DownstreamTemperature
Temperature at downstream end of pipe (C)
UpstreamEnthalpy
Energy at upstream end of pipe (kJ/kgmole)
DownstreamEnthalpy
Energy at downstream end of pipe (kJ/kgmole)
UpstreamDensity
Density at upstream end of pipe (kg/m3)
DownstreamDensity
Density at downstream end of pipe (kg/m3)
UpstreamFlowRegime
Flow regime at upstream end of pipe
DownstreamFlowRegime
Flow regime at downstream end of pipe
CanCalc
Can calculate
Duty
Heat transferred (kJ/h)
FrictionFactor
Friction factor
Dp_Fittings
Pressure drop due to fittings (bar)
RatedFlow
The rated flow (kg/h)
ReynoldsNonRated
Reynolds non-rated
ReynoldsRated
Reynolds rated
Reynolds
Reynolds number
SourcePres
Pressure of attached source node (bar a)
Equivlength
Equivalent length (m)
UpstreamEnergy
Energy at upstream end of pipe (kJ/h)
DownstreamEnergy
Energy at downstream end of pipe (kJ/h)
UpstreamEnthalpyEnergy
Upstream enthalpy energy
DownstreamEnthalpyEnergy
Downstream enthalpy energy
UpstreamMachNoNonRated
Upstream non-rated Mach number
DownstreamMachNoNonRated
Downstream non-rated Mach number
UpstreamMachNoRated
Upstream rated Mach number
DownstreamMachNoRated
Downstream rated Mach number
UpstreamMachNo
Mach number at upstream end of pipe
DownstreamMachNo
Mach number at downstream end of pipe
UpstreamPresProp
Upstream pressure property
DownstreamPresProp
Downstream pressure property
UpstreamRhoV2NonRated
Upstream non-rated Rho V2
DownstreamRhoV2NonRated
Downstream non-rated Rho V2
UpstreamRhoV2Rated
Upstream rated Rho V2
DownstreamRhoV2Rated
Downstream rated Rho V2
UpstreamRhoV2
Momentum at upstream end of pipe (kg/m/s2)
DownstreamRhoV2
Momentum at downstream end of pipe (kg/m/s2)
UpstreamVapourFraction
A File Format
Description
Upstream vapour fraction
DownstreamVapourFraction
Downstream vapour fraction
UpstreamProbChoked
Upstream probable choked
DownstreamProbChoked
Downstream probable choked
UpstreamProbMachNo
Upstream probable Mach number
DownstreamProbMachNo
Downstream probable Mach number
ProbNoise
Probable noise
213
Attribute
ProbSourcePres
Description
Probable source pressure
ProbSource
Probable source
UpstreamProbRhoV2
Upstream probable Rho V2
DownstreamProbRhoV3
Downstream probable Rho V2
ProbSlugs
Probable slug flows
UpstreamProbTemp
Upstream probable temperature
DownstreamProbTemp
Downstream probable temperature
UpstreamProbVelLiq
Upstream probable liquid velocity
DownstreamProbVelLiq
Downstream probable liquid velocity
UpstreamProbVelVap
Upstream probable vapour velocity
DownstreamProbVelVap
Downstream probable vapour velocity
PresBody
Body pressure
DenBody
Body density
VelBody
Body velocity
Estimate
Estimate
CannotTear
Cannot tear
WallTemperature
Temperature of pipe wall (C)
MaxStep
Maximum step
MaxFlow
Maximum flow
MinFlow
Minimum flow
HtcRadExt
External radiative HTC
ExtTemperature
External temperature
UpstreamVelLiqNonRated
Upstream non-rated liquid velocity
DownstreamVelLiqNonRated
Downstream non-rated liquid velocity
UpstreamVelLiqRated
Upstream rated liquid velocity
DownstreamVelLiqRated
Downstream rated liquid velocity
UpstreamVelLiq
Upstream liquid velocity
DownstreamVelLiq
Downstream liquid velocity
UpstreamVelVapNonRated
Upstream non-rated vapour velocity
DownstreamVelVapNonRated
Downstream non-rated vapour velocity
UpstreamVelVapRated
Upstream rated vapour velocity
DownstreamVelVapRated
Downstream rated vapour velocity
UpstreamVelVap
Upstream vapour velocity
DownstreamVelVap
Downstream vapour velocity
PresDrop
Pressure drop over pipe (bar)
UpstreamPressure
Pressure at upstream end of pipe (bar a)
DownstreamPressure
Pressure at downstream end of pipe (bar a)
TotalPresDrop
Total pressure drop
EquivlengthForPipeSummary
Equivalent length
Phase
214
Attribute
Description
ScenarioName
A File Format
Attribute
Description
SegmentName
SegmentEnd
End of the pipe segment
Phase
Phase description
Density
Density of the phase (kg/m3)
Enthalpy
Energy of the phase (kJ/kgmole)
Entropy
Entropy of the phase (kJ/kgmole/K)
Fraction
Fraction of the phase
HeatCap
Heat capacity of the phase (kJ/kgmole/K)
MolWt
Mol Wt of the phase
SurfTen
Surface tension of the phase (dyne/cm)
ThermCond
Thermal conductivity of the phase (W/m/K)
Viscosity
Viscosity of the phase (cP)
ZFactor
Z Factor of the phase
CompResults
Attribute
Description
ScenarioName
SegmentName
FluidType
Fluid type
Basis
Basis
MolWt
The molecular weight of the fluid
Fraction
The mole fraction of each component
Report File Formats
The printouts can be customized to a limited extent using a XML file with the
extension “.xml”. This file may be edited using any ASCII text editor such as
the NOTEPAD application distributed with Microsoft Windows.
The default “.xml” file for the printed reports is: ReportFormat.xml
By default, the report format file is located in the Aspen Flare System
Analyzer program directory. You can change the location and “.xml“ file for
the reports on the Reports tab on the Preferences Editor.
A File Format
215
Fig A.1
The following defines which variable may be printed with each report:
216
Variable Name
Variable Description
ambient
Ambient temperature
backpres
Back pressure
basis
Composition basis
class
Pipe class
conductivity
Thermal conductivity
connections
Item connections
densitydown
Downstream density
densityup
Upstream density
description
Description
dsn
Downstream node
duty
Heat loss
elevation
Elevation change
energy
Energy
energyflowdown
Downstream energy flow
A File Format
A File Format
Variable Name
energyflowup
Upstream energy flow
enthalpy
Enthalpy
enthalpyflowdown
Downstream enthalpy flow
enthalpyflowup
Upstream enthalpy flow
enthalpyup
Upstream enthalpy
enthalpydown
Downstream enthalpy
entropy
Entropy
entropydown
Downstream entropy
entropyup
Upstream entropy
equivlength
Equivalent length
exttemperature
External temperature
fittinglist
Fitting list
fittingsa
Fitting loss A
fittingsb
Fitting loss B
flange
Flange diameter
fractiondown
Downstream phase fraction
fractionup
Upstream phase fraction
frictionfractor
Friction factor
group
Item group
headmach
Header mach number
headvelvap
Header vapor velocity
headvelliq
Header liquid velocity
headrhov2
Header rho V2
headnoise
Header noise
heatcapdown
Downstream heat capacity
heatcapup
Upstream heat capacity
hia
Enthalpy A coefficient
hib
Enthalpy B coefficient
hic
Enthalpy C coefficient
hid
Enthalpy D coefficient
hie
Enthalpy E coefficient
hif
Enthalpy F coefficient
htcradext
External radiative HTC
htcoverall
Overall HTC
htcexternal
External HTC
htcinternal
Internal HTC
id
Item ID
ignored
Item ignored
inletlength
Inlet pipe length
217
218
Variable Name
inletelevation
Inlet pipe elevation change
inletmaterial
Inlet pipe material
inletroughness
Inlet pipe roughness
inletnominal
Inlet pipe nominal diameter
inletschedule
Inlet pipe schedule
inletinternal
Inlet pipe internal diameter
inletclass
Inlet pipe class
Inletfittingsa
Inlet pipe fitting loss A
Inletfittingsb
Inlet pipe fitting loss B
insname
Insulation description
insthick
Insulation thickness
insconductivity
Insulation conductivity
internal
Internal diameter
length
Segment length
lmultiply
Length multiplier
location
Segment location
machdown
Downstream mach number
machup
Upstream mach number
massflow
Mass flow
material
Material of construction
methoddamping
Damping factor
methodelements
Two phase elements
methodfriction
Friction factor
methodfitlos
Fitting loss method
methodhordp
Horizontal 2 phase pressure drop method
methodincdp
Inclined pressure drop
methodverdp
Vertical 2 phase pressure drop method
methodvle
VLE method
molarflow
Molar flow
molwt
Molecular weight
molwtdown
Downstream molecular weight
molwtup
Upstream molecular weight
multiply
Fittings equation multiplier
name
Item name
nbp
Normal boiling point
node
Node
nodetype
Node type
noise
Noise
nominal
Nominal pipe diameter
A File Format
A File Format
Variable Name
number
Index number
offset
Fittings equation offset
omega
Acentric factor
omegasrk
SRK acentric factor
orificearea
Orifice area
orifice
Orifice
pc
Critical pressure
phase
Phase label
pressource
Static source back pressure
presallow
Allowable back pressure
presdown
Downstream static pressure
presdrop
Pressure drop
presdropfriction
Static pipe friction loss
presdropacceleration
Static pipe acceleration loss
presdropelevation
Static pipe elevation loss
presdropfittings
Static pipe fitting loss
presin
Inlet pressure
preslimit
Back pressure limit
presup
Upstream static pressure
ratedflow
Rated mass flow
refer
Literature reference
regime
Flow regime
resize
Resizable flag
reynolds
Reynolds number
rhov2up
Upstream rho V2
rhov2down
Downstream rho V2
roughness
Wall roughness
schedule
Pipe schedule
si
Entropy coefficient
stddensity
Standard density
surftendown
Downstream surface tension
surftenup
Upstream surface tension
tailmach
Tailpipe mach No.
tailnoise
Tailpipe noise
tailpipe
Tailpipe flag
tailrhov2
Tailpipe rho V2
tailvelliq
Tailpipe liquid velocity
tailvelvap
Tailpipe vapor velocity
tc
Critical temperature
219
220
Variable Name
tempcalc
Inlet temperature calculations
tempdown
Downstream temperature
tempout
Outlet temperature
tempspec
Inlet temperature specification
tempup
Upstream temperature
thermconddown
Downstream thermal conductivity
thermcondup
Upstream thermal conductivity
type
Item type
usn
Upstream node
valvecount
Number of valves
valvetype
Valve type
vapfrac
Source vapor fraction
vc
Critical volume
vchar
Characteristic volume
veldown
Downstream velocity
velup
Upstream velocity
visca
Viscosity A coefficient
viscb
Viscosity B coefficient
viscdown
Downstream viscosity
viscup
Upstream viscosity
wall
Wall thickness
walltemperature
Wall temperature
watson
Watson characterisation parameter
wind
Wind velocity
zfactordown
Downstream compressibility factor
zfactorup
Upstream compressibility factor
A File Format
B References
1
“GPSA Engineering Data Book”.
2
“Chemical Engineering Volume 1”, J. M. Coulson and J. F. Richardson,
Pergamon Press, 2nd Edition.
3
“Viscosity of Gases And Mixtures”, I. F. Golubev, National Technical
Information Services, TT7050022, 1959.
4
“Chemical Process Computations 1, Chemical Engineering-Data
Processing”, Raman, Raghu, Elsevier Applied Science Publishers Ltd, 1985.
5
“Journal Of Physics”, D. J. Berthalot, P.3 ,263.
6
“Technical Data Book-Petroleum Refining”, American Petroleum Institute,
1977.
7
“A Computer Program for the Prediction of Viscosity and Thermal
Conductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanley, NBS
Technical Note, 1039, 1983.
8
R.W. Hankinson and G.H. Thompson, AIChE Journal, 25, 653, 1979.
9
“A Study of Two-Phase Flow in Inclined Pipes”, H.D. Beggs and J.P. Brill, J.
Petrol. Technol., P. 607, May, 1973.
10 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3,
1982 by Campbell Petroleum Series, 2nd edition, 1990.
11 J. Orkiszewski, Journal of Petroleum Technology, B29-B38, June, 1967.
12 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3,
1982 by Campbell Petroleum Series, 2nd edition, 1990.
13 API Technical Data Book Volume 1, American Petroleum Institute, 1983.
14 R.W. Hankinson and G.H. Thompson, A.I.Ch.E. Journal, 25, No. 4, P.653
1979.
15 “The Properties of Gases &Liquids”, R.C. Reid, J.M. Prausnitz and B.E.
Poling, McGraw-Hill, Inc., 1987.
16 “A Computer Program for the Prediction of Viscosity and Thermal
Conductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanly, NBS
Technical Note 1039.
17 “Molecular Thermodynamics of Fluid Phase Equilibria”,J.M. Pausnitz, R.N.
Lichtenthaler and E.G. Azevedo, 2nd Edition, McGraw-Hill, Inc. 1986.
18 C.H. Twu, IEC. Proc Des & Dev, 24, P. 1287, 1985.
19 “Viscosity of Crude-Oil Emulsions”, W. Woelfin, Spring Meeting, Pacific
Coast District, Division of Production, Los Angeles, Calif., Mar. 10, 1942.
20 W.R. Gambill, Chem Eng., March 9, 1959.
B References
221
21 “An Explicit Equation for Friction Factor in Pipe”, N.H. Chen, Ind. Eng.
Chem. Fund., 18, 296, 1979.
22 “Sizing, Selection, and Installation of Pressure - Relieving Devices in
Refineries”, API Recommended Practice 520, Part I, 6th Edition, American
Petroleum Institute, March, 1993.
23 “Guide for Pressure-Relieving and Depressuring Systems”, API
Recommended Practice 521, 3rd Edition, American Petroleum Institute,
November, 1990.
24 “Easily Size Relief Devices and Piping for Two-Phase Flow”, J.C. Leung,
Chem. Eng. Prog., P. 28, December, 1996.
25 “Internal Flow Systems”, D.M. Miller, 2nd Edition, BHR Group Limited,
1990.
26 “Flow of Fluids Through Valves, Fittings and Pipe”, Crane Technical Paper
410M. 1988.
27 “PIPE 3, Single and Two-Phase Pressure Drop Calculations in Pipeline
Systems”, HTFS Design Report 38, 1996.
28 “Les Pertes de Charges dans les Écoulements au Travers de”, A. Gardel,
Bulletin Technique de la Suisse Romande, 83, 1957.
222
B References
C Glossary of Terms
Adiabatic Flow
Adiabatic flow is the constant enthalpy flow of a fluid in a pipe.
Choked Flow
The velocity of a fluid in a pipe of constant cross-sectional area cannot exceed
the sonic velocity of the fluid. If the flow of fluid in a pipe is great enough that
the sonic velocity is reached, then a pressure discontinuity is seen at the exit
end of the pipe.
Critical Pressure
The critical pressure is the pressure at which the vapor density and liquid
density of a substance may be the same.
Critical Temperature
The critical temperature is the temperature at which the vapor density and
liquid density of a substance may be the same.
Dongle
See Security Device.
Equivalent Length
The equivalent length of a pipe is the straight length of pipe which would
create the same pressure drop as the actual pipe length plus losses due to
bends and fittings.
C Glossary of Terms
223
Isothermal Flow
Isothermal flow is the constant temperature flow of a fluid in a pipe. In
general when the pressure of a gas reduces, there is a small change in
temperature. This assumption leads to a small error in the calculated pressure
profile. In practice, for pipes of length at least 1000 diameters, this difference
does not exceed 5% and in fact never exceeds 20%.
MABP
The Maximum Allowable Back Pressure on a relief device is the maximum
pressure that can exist at the outlet of the device without affecting the
capacity of the device.
In general the MABP for a conventional pressure relief valve should not
exceed 10% of the set pressure at 10% overpressure.
In general the MABP for a balanced pressure relief valve should not exceed
40% of the set pressure at 10% overpressure.
Mach Number
Mach number is the ratio of the fluid velocity to the sonic velocity in the fluid.
Node
Nodes define the connection points between pipes, and pipes with sources.
Each node must have a unique name.
Reduced Pressure
Reduced pressure is the ratio of the absolute pressure to the critical pressure
of the fluid.
Reduced Temperature
Reduced temperature is the ratio of the absolute temperature to the critical
temperature of the fluid.
Scenario
A scenario represents a set of flow and compositional data for all sources in
the system. It may also represent a particular set of limiting operating
conditions.
224
C Glossary of Terms
Schedule
The schedule of a pipe defines a standard thickness for a given nominal pipe
size. In general, flare and vent systems are constructed from schedule 40 or
80 pipe.
Security Device
The hardware device that is connected to the parallel port of the computer.
Source
A source refers to a fluid entering the piping network regardless of the type of
pipe fitting from which it enters. the fluid is defined in terms of its
composition, mass flowrate, pressure and temperature.
Static Pressure
The pressure acting equally in all directions at a point in the fluid.
Physical properties are calculated at the static pressure condition.
Tailpipe
The section of pipe between the discharge flange of the source valve and the
main collection header is generally referred to as a tailpipe.
Total Pressure
The sum of the static and velocity pressures.
Velocity Pressure
Given by
C Glossary of Terms
ρU 2
, also called the kinematic pressure.
2
225
Index
A
Automation 115
B
binary interaction parameters 11
C
calculations
sizing 104
speed 103
status 101
stop 101
type 101
Component Editor 6
Component Manager 3
components
binary interaction parameters 11
changing 11
combining 11
estimating unknown properties 10
list 4
name string 5
selecting 4
selection filter 5
type 4
updating with user data 10
Connector 43
Control Valve 71
D
data
adding/deleting 109
filters 108
printing 109
protection 110
tables 109
Database Editor
226
Index
component 112
fittings 112
pipe schedule 110
database features
adding/deleting data 109
grid controls 108
F
Flare Tip 95
Flow Bleed 47
H
Horizontal Separator 50
M
modeling flare networks
primary objectives 102
recommended sequence 102
N
Node Manager 41
nodes
Connector 43
Control Valve 71
Flare Tip 95
Flow Bleed 47
Horizontal Separator 50
Orifice Plate 56
Relief Valve 81
Tee 60
Vertical Separator 65
Nodes 41
noise 186
O
Orifice Plate 56
P
password
setting 110
physical properties 178
Pipe Class Editor 39
Pipe Manager 25
pipes
multiple editing 38
Pipe Class 39
pressure drop methods 157
Index
227
R
Relief Valve 81
S
Scenario Editor 17
Scenario Manager 16
scenario selector 16
scenarios 15
adding single source 23
adding/editing 17
tools 23
sizing
recommended procedure 104
source tools 94
adding single source scenarios 95
updating downstream temperatures 95
sources
Control Valve 71
Relief Valve 81
tools 94
Status bar 101
T
Tee 60
V
vapour-liquid equilibrium 175
Vertical Separator 65
VLE method 103
228
Index

Aspen Flare System Analyzer Reference Guide

Transcription

Similar documents

Fernco Flexible Coupling Installation - Fernco

Hymax Couplings 1.5

lfucg follows kytc lead and approves ads and hancor hdpe pipe for

Fernco Flexible Coupling Installation - Fernco

Aviva Stadium

VIDEO SCANNER LASER FOR TV INSPECTION AND

Chart L4: Details (sidewalks, stormwater management)

The New American Home

great lengths - Laney Directional Drilling

LGOBO SALE SHEET