BOA-Systronic 2 MB

Transcription

BOA-Systronic 2 MB

KSB Know-how, Volume 2
B OA- Sy s t ro n i c
Contents
Intelligent pump and valve management saves energy . . . . . . . . . . . . . 2
1
Heating circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
System concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5
Volume flow rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
Circulator pump heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7
Hydraulic balancing of branch circuits . . . . . . . . . . . . . . . . . . 12
8
Differential pressure control elements . . . . . . . . . . . . . . . . . . . 14
9
Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10
Practical testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1 Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.2 Circulator selection for BOA-Systronic . . . . . . . . . . . . . . . . . . 19
10.3 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.4 External temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.5 Volume flow rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.6 Differential pressures of the pumps . . . . . . . . . . . . . . . . . . . . . 22
10.7 Electrical pump power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11
Payback period for BOA-Systronic . . . . . . . . . . . . . . . . . . . . . 24
11.1 Control valve investment and energy savings . . . . . . . . . . . . . . 24
11.2 Investment costs for heating circuit with Riotec pump . . . . . . 25
11.3 Investment costs for heating circuit with Rio-Eco pump . . . . . 26
11.4 Total savings comparison Riotec/Rio-Eco . . . . . . . . . . . . . . . . 26
12
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
13
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
List of figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
List of tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1
060206_knowhow05_e_IS 1
06.02.2006, 12:49:41 Uhr
Intelligent pump and valve management saves energy
The new BOA - Systronic system solution improves the supply temperature control
of heating circuits. It opens up a previously unused potential for saving electrical
energy used by the circulator pump.
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06.02.2006, 12:49:42 Uhr
1
Heating circuit
1
Heating circuit
• Mixing or injection-type
systems produce a constant
volume flow rate through the
Every heating circuit consists of
consumer installations1. As a
several control components
result, part-load conditions –
such as the circulator pump and
which account for more than
the control valve, which are
95% of the operating period –
connected by pipes. The circu-
result in the circulator pump
lator pump conveys the heating
handling predominantly cold
water from the heat generator
return water most of the time.
(boiler) to the consumer instal-
• In a mixing or injection-type
lations, and the control valve
system, the discharge head of
adjusts the volume flow rate
the variable-speed circulator
pumped through the consumer
pump remains constant, irre-
installations. Conventional
spective of the actual load
heating set-ups can be charac-
conditions, i.e. irrespective of
terized as follows:
external temperature. Only
external heat gains will result
THE CONTROL COMPO-
in energy savings, depending
NENTS IN CONVENTION-
on the set pump characteristic
AL HEATING SYSTEMS ARE
curve (∆p = constant or ∆p =
NOT COORDINATED
variable).
• If several heating circuits of
• The circulator pump and
a mixing or injection-type
the control valve fitted in con-
system branch off a main feed
ventional, mixing or injec-
circuit, they must be balanced
tion-type systems operate in-
manually.
dependently, without coordination between the two components. There is no system
knowledge about the hydraulic conditions in the heating
circuit, so that some of the
hydraulic energy supplied by
the circulator pump may actually be destroyed by valves
and differential pressure control elements elsewhere in the
heating circuit.
1
Constant volume fl ow rate through consumer installations: results from the hydraulic confi guration of the main feed circuit (e.g. 3-way mixing
valve). Whether the system is operating under nominal load or part-load conditions, the circulator pump will always deliver the nominal
volume fl ow rate calculated for the design point. Only when external heat is acting on the consumer installations will the level of this volume
fl ow rate be adjusted by the control function of the thermostats.
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2
System concept
2
System concept
An analysis of this situation re-
The supply temperature is in-
main feed manifold is now
sulted in the BOA-Systronic
creased by the higher-level con-
automatically performed via the
system concept, which has the
troller. This results in hydraulic
circulator pump, which reduces
clearly defined benefit of reduc-
savings regarding both volume
commissioning costs for the
ing the running costs of the
flow rate ∆Q and discharge
heating circuit. When the heat-
heating circuit.
head ∆H, whose product is pro-
ing circuit of a conventional
portional to the corresponding
mixing or injection-type system
electrical power savings for the
is commissioned, the tempera-
SAVINGS POTENTIAL BY
SYSTEM CONCEPT
circulator
pump2 .
ture difference between supply
and return (temperature differ-
BOA-Systronic coordinates the
A positive side effect is that
ential) is set for the design point
operation of circulator pump
static hydraulic balancing at the
using the balancing valve, usu-
and control valve. Depending
on the control signal issued by
the higher-level heating controller the two BOA-CVE SuperCompact control valves adjust
the resulting volume flow rate
pumped through the consumer
installations. At the same time,
the appropriate discharge head
Higher-level heating
controller
setpoint is transmitted to the
variable-speed drive of the circulator pump.
BOA-Systronic transforms the
conventional, constant-flow
mixing or injection-type system
into a variable-flow system, and
adjusts the discharge head of
the circulator pump to the reduced volume flow rates via the
system control curve.
The radiator diagram illustrates
the physical fact that – at identical heat output – the volume
flow rates provided to the consumer installations can be reduced if the supply temperature
is increased at the same time.
2
Fig. 01 Hydraulics schematics of BOA-Systronic
t2
Electrical power input of circulator pump: P
= constant · ∫ Q(t) · H(t)dt.
electr.
t1
The constant describes the efficiency of circulator pump and frequency inverter as well as water density and acceleration due to gravity.
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06.02.2006, 12:49:43 Uhr
2
System concept
ally by throttling this valve.
ic balancing of branch circuits,
The pressure drop across the
they can even be replaced by
valve may amount to several
more cost-effective balancing
tenths of bar. With BOA-Sys-
valves. Variable volume flow
tronic, this step is dispensed
rate control by BOA-Systronic
with.
has no influence on the hydraul-
As BOA-Systronic produces
ic balancing of the branch cir-
only the discharge head actually
cuits, which is performed for
required to overcome system
the design point.
resistance, flow noises are prevented, even with external heat
input, and expensive differential pressure control elements
are not required for balancing
the heating circuits. For hydraulKNOWLEDGE ABOUT
PIPING CHARACTERISTIC
OF HEATING CIRCUIT
Fig. 02 Comparison of systems
Conclusion
The savings realised by BOA - Systronic result from knowledge about the hydraulic
conditions in the heating circuit. They are completely independent from differential
pressure control of the circulator pump. With BOA - Systronic , differential pressure
control of the circulator pump is effected as before.
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3
Components
3
Components
The transformation into a sys-
ing on the actual load (external
and thus the hydraulic resist-
tem with variable volume flow
temperature).
ance of the heating circuit. The
presupposes that the partial
The control unit is mounted on
measuring valve remains fully
volume flows are hydraulically
the main control valve at the
open both during commission-
decoupled and that information
factory. The BOA-Control
ing and over the entire operat-
about the flow rates required in
IMS 4
valve is used here to
ing range and – due to its very
the heating circuit is available.
measure the volume flow rate at
low ζ-coefficient – acts just like
For this reason, BOA-Systronic
the main feed manifold during
a piece of pipe. The measuring
comprises three valves. The two
commissioning. This measuring
computer is not included in the
BOA-CVE SuperCompact con-
signal is used to determine the
system scope of supply.
trol valves are used for adjust-
discharge head of the circulator
ing volume flow through the
pump for the design point as
consumer installations depend-
well as the system control curve
Fig. 03 BOA-Systronic components
3
4
5
BOA- CVE SuperCompact: Automated shut-off and control valve for HVAC applications with smart electric actuator. The valve is produced
in nominal sizes from DN20 to DN150 and nominal pressure class PN6/10/16. Thanks to its compact design, it is the smallest and lightest
valve of this pressure class manufactured in series production today, enabling the space-saving design of air-conditioning and heating centrals.
Due to its low weight, the valve is easy to install and handle. The self-calibration feature of the actuator is another benefi t, which does away
with the adjustment of limit switches.
BOA- Control IMS: The valve measures volume fl ow rates independently from valve travel positions and minimum differential pressures.
Unlike on conventional valve models, the measurement accuracy is constant across the entire valve travel. The measuring signal is read and
processed by a measuring computer. Valves of this kind are often insulated, and any identifi cation on their bodies may be diffi cult to read.
After start-up, the computer display therefore fi rst shows the nominal diameter of the connected valve. The operator can then choose via two
keys whether the current fl ow rate is to be indicated [in m 3 /h] or the temperature of the fl uid handled [in C°]. Volume fl ow rates can be checked
within a matter of seconds in this way. BOA- Control IMS, which has a linear characteristic, can also be used as shut-off valve. Thanks to a
travel stop with a protective cap, the valve can be set exactly to its original position once the shut-off process has been completed.
ζ-coeffi cient: describes the resistance a valve offers to the fl uid passing through it. The ζ-coeffi cient depends on the valve type and design.
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4
Control
4
Control
BOA-Systronic is a control sys-
supply temperature measured,
tem which is installed down-
the higher-level controller gen-
stream of the heating system’s
erates the control error signal,
control unit. It does not replace
which is the input of the (PI or
the higher-level controller.
PID) control algorithm. This
control algorithm generates a
HIGHER-LEVEL CONTROL-
signal, which – in conventional
LER IS RETAINED
mixing / injection-type systems –
is then transmitted to the control
Supply temperature control
valve.
remains the task of the higher-
This output control signal from
level controller. Input signals
the higher-level controller is the
for this controller are, among
input for BOA-Systronic, i.e. it
others, the external tempera-
is transmitted to the Systrobox
ture measured and the supply
control unit. With the help of
temperature measured in the
the system control curves deter-
heating circuit. With the help of
mined during commissioning,
the heating curve stored in the
Systrobox translates the control
higher-level control unit, the
signal into two separate control
setpoint for the supply tempera-
signals for the two BOA-CVE
ture of the heating circuit is
SuperCompact control valves
generated on the basis of the
and into a discharge head set-
external temperature measured.
point for the circulator pump.
Based on this setpoint and the
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06.02.2006, 12:49:51 Uhr
5
Volume flow rates
5
Volume flow rates
type systems. As a result, pre-
water, whereas the control valve
dominantly cold return water
in the mixing line adjusts the
is pumped through the heating
volume of cold return water to
Thermal output of the heating
circuit under part-load
be mixed in. The additional op-
circuit is calculated for the
conditions.
timizing effect of external heat
design point as the product of
The volume flow rate through
load compensation by the ther-
volume flow rate Q and temper-
the heating circuit is only re-
mostatic valves remains un-
ature differential ∆T.
duced by the regulating func-
affected.
tion of the thermostatic valves
The radiator diagram illustrates
(external heat load compensa-
that volume flow rate can be re-
tion).
duced while thermal output at
Pth = 1.163 · Q · ∆T
Conventional systems
the consumer installations stays
BOA-Systronic
the same, if the supply tempera-
figuration, conventional mixing
The innovative control concept
ture is increased accordingly.
of BOA-Systronic regulates
Two methods can be used,
provide the consumer installa-
thermal output by variation of
which can be realized by mak-
tions only with a constant vol-
the temperature differential and
ing use of a standard function
ume flow rate, irrespective of
the volume flow rate, consider-
offered by the heating control-
the heating controller’s signal.
ably reducing the water volume
ler.
The volume flow in the supply
to be pumped through the heat-
line is coupled with the volume
ing circuit. This is possible
flow of the cold return water
because the two BOA-CVE
Parallel shift of heating
curve
pumped through the mixing
SuperCompact control valves
The controller’s heating curve is
line (Fig. 04).
decouple the volume of heating
shifted parallel by a fixed
water coming from the supply
amount towards higher supply
line from the volume of cold re-
temperatures. The controller
turn water pumped through the
adds the fixed amount ∆T to the
So thermal output of the heating
mixing line.
supply temperature setpoint
circuit can only be regulated via
The main control valve installed
(parallel shift of the heating
the temperature differential in
in the supply or return line regu-
curve). Due to the increased
conventional mixing / injection-
lates the volume of heating
temperature differential, the
or injection-type
systems 6
can
Qtotal =Q1supply+Q2mixing
Q 1 supply
Q total
(hot)
Volume flow rate Q [%]
Owing to their hydraulic con-
Q total
100
Q 2 mixing
80
60
40
20
Q 1 supply
0
Q 2 mixing (cold)
0
20
40
60
80
100
Controller signal [%]
Fig. 04 Volume flow rates of 3-way valve
6
3-way configuration: In a 3-way mixing valve, the fl uids to be mixed enter the valve via two input ports and the sum of their fl ow exits
through a single output port. The ratio between the fl ow rates through both inlet ports is determined by the stem position. The sum of the
throttling cross-sections on both inlet ports is constant over the entire valve travel. The valve therefore provides a constant volume fl ow at its
outlet port, independent of stem position.
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5
Volume flow rates
nominal volume flow rate is
In principle, this new design
design point of the circulator
reduced by 25% in all cases,
point can also be achieved with
pump remain unchanged. In
resulting in a new design point
a conventional hydraulic con-
this case, the investment costs
for the circulator pump (Fig. 05)
figuration. However, BOA-
for the circulator pump and the
Systronic offers a number of
other valves cannot be reduced.
INCREASED SUPPLY TEM-
benefits.
PERATURE BY PARALLEL
• The consultant can size the
SHIFT OR SLOPE MODIFI-
consumer installations of the
CATION OF HEATING
heating circuit as usual
CURVE
• The consultant can use the
benefits offered by BOA-
Thanks to the new design
Systronic without changing
point, investment costs for the
his planning
circulator pump and the valves
• The consultant saves
in the heating circuit can be
planning work and thus time
reduced considerably.
and costs
• Normally, a circulator
rating can be selected
Slope modification of heating curve
Benefit: Substantially reduced
The controller’ s heating curve
investment costs for the circu-
is shifted towards higher supply
lator pump
temperatures only if the system
pump with a lower output
• The nominal diameter of
is running under part-load conditions. Depending on the value
be chosen one nominal diam-
of the control signal, the control-
eter smaller.
ler internally adds an amount
Benefit: Reduced investment
∆T to the supply temperature
costs for piping, shut-off
setpoint (slope modification of
valves and strainers, including
heating curve). The nominal
insulation.
volume flow rate and thus the
Q 1 supply
(hot)
Q total
+
Q 2 mixing
(cold)
the heating circuit can usually
100
80
Q total
60
40
20
Q 2 mixing
Q 1 supply
0
0
20
40
60
80
100
Controller signal [%]
Fig. 05 Reduced volume flow rates of BOA-Systronic
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6
Circulator pump heads
6
Control IMS valve measures the
cuit, the pressure losses in the
volume flow rate in the heating
consumer installations, balanc-
circuit and thus determines the
ing valves, differential pressure
Owing to the hydraulic config-
required nominal discharge head
control elements, strainers as
uration of conventional mixing
of the circulator at the design
well as thermostatic and shut-
or injection-type systems, the
point. The values obtained are
off valves.
circulator pump head cannot be
then used to determine the
The volume flow rate and dis-
matched to the system control
system constant of the heating
charge head are shown in nor-
curve. The circulator pump can
circuit. As a result, the hydraul-
malized representation here.
only react to reduced volume
ic resistance of the heating
The circulator pump of a mix-
flow rates resulting from the
circuit is known, and the control
ing or injection-type system can
control function of the thermo-
unit knows the circulator head
only respond to reduced volume
static valves at the consumer in-
required for the individual load
flow rates (external heat gain)
stallations. Depending on the
conditions.
with a constant discharge head,
pump curve selected, the dis-
thus saving a certain amount of
charge head either remains
The H/Q diagram on page 11
constant (∆p = constant) or is
shows an example of the possi-
reduced accordingly (∆p =
ble discharge heads of a differ-
NEW DESIGN POINT FOR
variable).
ential pressure controlled
THE PUMP
energy.
pump. The diagram shows the
BOA-SYSTRONIC CON-
H/Q data of a pump controlled
With BOA-Systronic, parallel
TROLS THE PUMP AS A
independently of throughflow
shift of the heating curve results
FUNCTION OF THE SYSTEM
(∆p = constant) and offers a
in the new nominal volume
CURVE OF THE HEATING
comparison between a conven-
flow rate
CIRCUIT
tional system and a system
equipped with BOA-Systronic.
Q new = 0.75 · Q old
BOA-Systronic, by means of the
two control valves, adjusts the
The design point is represented
and, by application of the affin-
volume flow rate as a function
by the intersection of the system
ity law, yields the associated
of external temperature and
curve of the heating circuit with
discharge head of the circulator
measures the system curve of
the characteristic curve of the
pump:
the heating circuit during com-
circulator pump.
(see equation below)
missioning. As a result, the circulator’s discharge head can be
matched to the volume flow
(
H new = H old ·
Q new
Q old
2
)
(
= 100%·
75%
100%
2
) ·H
old
= 0.56 · H old
rate to be pumped. This is done
by means of the system control
The system curve describes the
The valve authority of the main
curve (Fig. 6). The system
resistance the volume flow has
control valve must then be add-
control curve is automatically
to overcome, and corresponds
ed to this value. It describes the
determined by measuring the
to the discharge head required
pressure drop at the control
volume flow rate during
of the circulator pump. It de-
valve, in relation to the differ-
commissioning; it is limited by
pends on the length and nom-
ential pressure to be produced
the minimum discharge head of
inal diameter of the supply and
by the pump (overall pressure
the circulator pump. The BOA-
return lines in the heating cir-
drop in the system). With BOA-
10
06.02.2006, 12:49:56 Uhr
6
Systronic, valve authority is
the BOA-Systronic controlled
pump curve set, the discharge
constant over the entire operat-
circulator pump moves along
head either remains constant
ing range. This correlation is
the system control curve. As
(∆p=constant) or decreases with
reflected in the system control
external temperature rises, the
decreasing volume flow rate
curve and explains why the sys-
operating point moves towards
(∆p=variable). All the familiar
tem control curve runs parallel
lower volume flow rates and
features of the variable-speed
to the system curve, at a slightly
lower discharge heads.
pump and the thermostatic
higher level (Fig. 6)
valves are retained.
ALL FEATURES OF THE
In our example, a new design
VARIABLE SPEED PUMP
point is established for the cir-
ARE RETAINED
culator pump: the nominal volume flow rate is reduced by
The diagram also illustrates the
25%, and the nominal dis-
effect the control function of
charge head of the circulator
the thermostatic valves has on
pump is reduced accordingly.
various operating points (exter-
As a result, a circulator pump
nal heat load). Under the influ-
with a lower performance rat-
ence of external heat load, the
ing can be selected.
operating point also moves
along the characteristic curve of
Depending on the external tem-
the differential pressure con-
perature, the operating point of
trolled pump. Depending on the
P el 1
Discharge head H [%]
P el2
=
constant Q1 H1
constant Q2 H2
=
Q1 H1
Q2 H2
180
Chara
o f f ixedc t e r i s t i c c u r v e
speed p
ump
160
Operating point, conventional
with external heat load
P el 11 = 84%
Design point, conventional
without external heat load
Pel 1 = 100%
140
120
External
heat effect
Characteristic curve of
variable speed pump ∆p = constant
100
Design point BOA-Systronic
P el 21 = 35%
80
External
heat effect
variable speed pump ∆p = constant
60
Operating point BOA-Systronic
part-load, with external heat load
P el 31 = 11%
40
External
heat effect
variable speed pump
20
System control curve
Syst
urv
em c
BO
A
st
-Sy
e
ron
Design point BOA-Systronic
P el 2 = 45%
ic
Operating point BOA-Systronic
part-load, without external heat load
P el 3 = 16%
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Fig. 06 Circulator pump heads (example)
11
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7
Hydraulic balancing of branch circuits
7
Hydraulic balancing of
branch circuits
BOA-Systronic operates the
heating circuit with variable
volume flow rates. The question
therefore arises whether the
branch circuits are hydraulically
balanced for these variable
operating points.
The branch circuits are hydraulically balanced for the design
point (nominal load). This ensures adequate heat supply to
the consumer installations in the
individual branch circuits. In
the following, the nominal load
case is indexed N, whereas the
Fig. 07 Heating circuit with branch circuits
part-load case is indexed T.
At the design point (nominal
mains unchanged. The pressure
The following is to show that
load), the differential pressure
drop at the valve then only de-
variable volume flow control by
at the balancing valve of the
pends on the volume flow rate
BOA-Systronic has no influence
branch circuit drops as follows:
(Q).
on branch circuit balancing.
Differential pressure at
The volume flow rates in branch
by means of balancing valves
nominal load:
QN
1
1
∆ pN = · ρ · ζ · w 2 = · ρ · ζ ·
2
2
A
BV1, BV2 and BV3. What is
Equation 1
circuits 1, 2 and 3 are adjusted
2
( )
of interest is the ratio of the
pressure drops at the balancing
where ρ is the water density, ζ is
The opening cross-section (A)
valves at nominal load
the valve’s zeta coefficient, w is
and the zeta coefficient (ζ) of
the flow velocity of the water, A
the valve remain unchanged.
(e.g.
∆ pN2
∆ pN1
) and
part load (e.g.
∆ pT2
∆ pT1
is the flow cross-section at the
throttling point, and Q N is the
).
volume flow rate at design point.
1
1 2
·ρ·ζ·
= constant = c
2
A
()
Equation 2
Hydraulic balancing of the
Differential pressure at the bal-
branch circuit is performed for
ancing valve therefore only
the design point (nominal load).
depends on a factor (c) which
After that, the throttling pos-
describes the valve and the vol-
ition of the balancing valve re-
ume flow rate (Q):
12
06.02.2006, 12:49:57 Uhr
7
Hydraulic balancing of branch circuits
nominal load:
∆ pN = c · Q 2 N
Differential pressure BV1
Equation 3
Equation 6
∆ pT1 = F2 ·∆ p N1
Under part-load conditions, the
differential pressure at the bal-
ancing valve (BV) is reduced as
∆ pT2 = F2 ·∆ p N2
follows:
Equation 7
parl load:
∆ pT = c ·(F·Q N ) 2
Equation 4
where factor F describes the
∆ pT3 = F2 ·∆ p N3
Equation 8
part-load level (0-100)%.
Inserting equation 3 in equation
Therefore, the ratios of these
4 yields
differential pressures are as
follows:
∆ pT = F2 ·∆ p N
Equation 5
resulting in the following differ-
∆ pT2
∆ pT1
=
∆ pN2
∆ pN1
Equation 9
ential pressures at nominal and
part-load for branch circuits 1,
2 and 3:
Conclusion
The same law governing differential pressures in
the branch circuits can be established for part load
conditions as for nominal load conditions. It is
therefore ensured that the branch circuits are actually
supplied with the necessary volume flow rate for the
thermal output required.
13
06.02.2006, 12:49:59 Uhr
8
Differential pressure control elements
8
Differential pressure
control elements
circulator pump is immediately
higher excess discharge head at
reduced by the differential pres-
the thermostatic valve (∆p 2 ), as
sure control valve in many cases!
does the fixed speed pump
By way of example, the H/Q
(∆p1).
If external heat is acting on a
diagram in fig. 08 compares the
room – sunlight, for instance –
influence of external heat gain
the thermostatic valves will re-
on the operating behaviour of a
duce the volume flows passing
fixed speed circulator pump, a
through the radiators in this
differential pressure controlled
room. If volume flow rates are
circulator pump of a mixing or
reduced, the circulator pump of
injection-type system, and a
a conventional heating system
differential pressure controlled
will either be operated with a
pump controlled by BOA-Sys-
constant or variable discharge
tronic. The diagram shows that
head, depending on the set
the BOA-Systronic controlled
pump curve. The reduced vol-
pump generates only little ex-
ume flow rate will result in a
cess differential pressure, which
reduced pressure drop in the
drops at the thermostatic valve.
piping. The excess differential
pressure produced by the circu-
NO DIFFERENTIAL
lator pump can only drop at the
PRESSURE CONTROL
thermostatic valve, which caus-
ELEMENTS REQUIRED
es considerable flow noise or
whistling. Differential pressure
This differential pressure results
control elements are often used
from the hydraulic resistance of
to prevent this. Their function
the heating circuit and the dis-
limits the increase in differen-
charge head of the circulator
tial pressure across the thermo-
pump controlled by BOA-
static valve, thus preventing
Systronic. The differential
flow noise. In conventional sys-
pressure controlled pump of a
tems, therefore, part of the dis-
mixing or injection-type system,
charge head provided by the
by contrast, produces a much
Conclusion
BOA -Systronic provides the circulator pump with the discharge head required for
the actual load conditions. No excess discharge heads are produced under part load
conditions, nor flow noises at the consumers. Expensive differential pressure control
elements for balancing the heating circuits can be dispensed with. For hydraulic balancing
of branch circuits, they can even be replaced by lower priced balancing valves.
14
06.02.2006, 12:49:59 Uhr
9
Commissioning
9
Commissioning
this procedure has been com-
termines the circulator’s discharge
pleted, the system knows the
head required for the design
circulator’s discharge head for
If parallel shift of the heating
point. To do so, the circulator
the design point and the system
curve is planned, BOA-Systronic
pump is started up with its
constant of the heating circuit,
will always reduce the volume
minimum discharge head. A
and thus its system curve.
flow rate for the design point by
corresponding volume flow rate
Therefore, the correlation be-
25 %, based on the volume flow
is produced in the heating cir-
tween discharge head and vol-
rate the system designer has cal-
cuit, which is measured by the
ume flow rate for the heating
culated for a conventional mixing
BOA-Control IMS valve at the
circuit is known.
or injection-type system.
main feed manifold. The
BOA-Systronic has to be config-
BOATRONIC M- 420 measur-
BOA-SYSTRONIC AUTO-
ured prior to commissioning.
ing computer converts this
MATICALLY DETERMINES
This is done by entering the value
measured value into an analog
THE OPTIMUM PUMP HEAD
of the volume flow rate deter-
(4-20)mA current signal and
mined for a conventional mixing
transmits it to the Systrobox
With the data stored for the
or injection-type system into the
control unit, where it is com-
volume flow rate at part load
commissioning software, together
pared against the value for the
conditions, BOA-Systronic then
with the nominal system diam-
(new) nominal volume flow
generates the system control
eter of BOA-Systronic (param-
rate. The circulator’s discharge
curve as well as the two valve
eterization). The nominal diam-
head is increased step by step,
control curves.
eter of the BOA-Control IMS
until the difference between set-
measurement valve corresponds
point and measured value falls
to this nominal system diameter.
below a certain limit. When
Discharge head H [%]
BOA-Systronic automatically de-
180
Operating point, conventional,
variable speed pump
Operating point, conventional,
fixed speed pump
160
H1
140
External
heat effect
Design point, conventional
120
100
H2
∆p1
80
∆p2
60
Operating point
BOA-Systronic
variable speed pump
External
heat effect
40
External
heat effect
Operating point
BOA-Systronic
variable speed pump
H3 ∆p
3
BO
y
A-S
str
oni
Sy
s
tem
cu
rve
c
Hydraulic
resistance
of heating circuit
20
0
0
10
20
30
40
Q part-load 60
70
Q NS 80
90
QN
110
120
Fig. 08 Excess circulator pump heads (example)
Q
Q
N
N Sys
Q
T
Design point of heating circuit with 3-way valve
∆p1 Differential pressure at thermostatic valve (fi xed speed pump)
Design point of heating circuit with BOA-Systronic
∆p2 Differential pressure at thermostatic valve
Part load condition (example)
(variable speed pump ∆p=const.)
∆p3 Differential pressure at thermostatic valve (BOA-Systronic)
15
06.02.2006, 12:49:59 Uhr
10
Practical testing
10
Practical testing
10.1
Plant
BOA-Systronic has been in use
in the office building of DeTeImmobilien in Heidelberg, Germany, since 2001. The heating
water is produced in a twoboiler system with a thermal
output of approx. 2 MW. Each
boiler is equipped with a
2-stage burner. The main feed
manifold is connected directly
Fig. 09 Two-boiler system
to the boilers (without hydraulic separator) and feeds 4 heat-
sections, any disturbances in
CONTROLLER TRANSMITS
ing circuits plus several other
room temperature (external
CONTROL SIGNAL TO BOA-
hot water circuits. Four heating
heat gain) are re-adjusted by
SYSTRONIC
controllers control supply tem-
means of the radiators’ thermo-
perature in the four building
static valves. Both circulator
The main control valve is
sections. The controllers are
pumps are differential pressure
supplied in nominal system
fitted in a separate control
controlled (∆p = constant).
diameter DN50 (Fig. 15). Fitted
cabinet in the plant room.
Table 01 demonstrates the
with an EA-C40 actuator, it is
benefits of BOA-Systronic by
installed in the supply line of the
FOUR HEATING CIRCUITS
comparing the performance
heating circuit. The designation
HEAT THE BUILDING
data of the two heating circuits.
EA-C40 means that this actuator has an actuation force of
BOA-Systronic supplies heat to
the West wing of the building.
The East wing is equipped with
a conventional mixing system.
Both building sections require
the same heat output. The
“Stat. Heizung West” heating
controller transmits its control
signal (for the control valve) to
the control unit of BOA-Systronic, where it is converted
into the load-dependent discharge head setpoint for the circulator pump and two separate
control signals for the two control valves. In both building
Fig. 10 Return manifold
16
06.02.2006, 12:50:00 Uhr
10
Practical testing
4,000 N. The photo shows the
al-position feedback (2-10)VDC.
terminal box for cable connec-
When combined with BOA-Sys-
tion and the black handwheel
tronic, it is configured with a
for emergency operation in the
linear valve characteristic and
event of a power failure. The
fed by an analog (2-10) VDC
smart actuator makes it pos-
voltage signal.
sible to select either a linear or
an equal-percentage valve
EA-C40 FOR NOMINAL
characteristic. Configuration is
SYSTEM DIAMETERS FROM
performed exclusively by means
DN 65
of the parameterization software.
The mixing valve is always selected two nominal diameters
smaller than the nominal system diameter and replaces the
swing check valve in the mixing
Fig. 11 Control cabinet
Parameter
line (Fig. 16).
East wing
(3-way configuration)
West wing
(BOA-Systronic)
Unit
300.00
300.00
kW
Temperature differential
20.00
27.00
K
Volume flow rate (max.)
13.00
9.75
m³/h
8.00
4.50
m
Circulator pump
Riotec 65 -100
Riotec 50 -100
Differential pressure control
∆ p = constant
∆ p = constant
DN65
DN50
No
+3.5
Thermal output
Discharge head (max.)
Nom. diameter of main heating circuit
Parallel shift of heating curve
K
Table 01: Performance data of
main feed circuits
2 ACTUATOR TYPES FOR
DIFFERENT NOMINAL
SYSTEM DIAMETERS
The actuator can either be
supplied with 24 VAC/DC or
230 VAC/DC. As standard, it is
capable of processing 230/24
VAC 3-point control signals as
well as analog (0/4-20) mA current or (0/2-10) VDC voltage
Fig. 12 Heating controllers for
Fig. 13 Main feed manifold,
signals and features active actu-
West and East wings
West and East wings
17
06.02.2006, 12:50:09 Uhr
10
Practical testing
In the event of a power failure,
dressed by an analog voltage
the valve can be actuated by
signal (2-10) VDC.
means of an Allen key.
The Systrobox is the “heart” of
EA-B12 FOR NOMINAL
BOA-Systronic. The control
SYSTEM DIAMETERS UP TO
unit stores the two valve control
DN50
curves for the main control
valve and the mixing valve, as
For applications other than
well as the system control curve
BOA-Systronic, this actuator
for the pump.
also offers the option of setting
a linear or equal-percentage
SYSTROBOX IS THE
valve curve.
“HEART” OF BOA-
A five-core cable supplies the
SYSTRONIC. IT RECEIVES
actuator with supply and con-
AND TRANSMITS ALL
trol voltage. As the terminals
SIGNALS.
Fig. 14 Main feed circuit with
are located inside the actuator,
BOA-Systronic
the cover must be removed prior
The control unit is powered by
to installation. Operating on a
24 VAC. It contains the inter-
It adjusts the volume flow rate
24 VAC/DC voltage supply,
face for powering the BOA-
in the mixing line in accordance
the actuator requires an ana-
TRONIC measuring computer
with the valve control curve
log (0/2-10)V control signal
and for receiving and process-
stored in the Systrobox. In this
and provides (2-10)VDC active
ing its measuring signal. As in-
case, it is of nominal size DN32
actual-position feedback. When
terface with the (higher-level)
and therefore equipped with ac-
combined with BOA-Systronic,
controller, it receives the con-
tuator type EA-B12, which has
it is configured with a linear
troller’s control signal and
an actuating force of 1,200 N.
valve characteristic and ad-
transmits the three control sig-
Fig. 15 Main control valve
Fig. 16 Mixing valve BOA-Systronic
BOA-Systronic
18
06.02.2006, 12:50:14 Uhr
10
Practical testing
nals simultaneously to the
pump and the control valves.
10.2
Circulator selection
for BOA -Systronic
The control valves receive a
k heating circuit =
8
= 0.0473
132
Equation 11
separate analog (2-10)VDC
The following analysis shows
control signal each, whereas the
that the Riotec 50-100 circula-
The example is based on a tem-
integrated FTT10 transceiver
tor pump selected, which is
perature differential of ∆T =
sends the currently required
controlled by BOA-Systronic, is
20K, and the heating curve of
discharge head as digital signal
oversized. The system curve of
the higher-level controller was
to the pump via LON bus. A
the heating circuit is calculated
shifted by 3.5K (parallel shift),
second pair of integrated LON
as the quotient of the pump
resulting in a new design point:
terminals serves to transmit the
head (H) and the square of the
the nominal volume flow rate is
LON output variables of BOA-
volume flow rate (Q):
reduced by 25%.
Systronic as well as any other
nodes of the LON bus to a
higher-level building management system.
(Equation 12: see below)
k heating circuit =
H
Q2
For selecting the circulator
Equation 10
pump operated with BOA-Systronic, the required discharge
Systrobox comes pre-assembled
The volume flow rate for the de-
head is calculated for the design
to the main control valve as
sign point of the conventionally
point, including equations 2
standard. However, it can also
equipped main feed circuit is
and 3.
3
be mounted on the mixing
Qnom = 13m /h. At this volume
(Equation 13: see below)
valve, as in the present case, or
flow rate, the Riotec 65-100
in the control cabinet.
pump can provide a maximum
This new design point [Q/H] =
head of approx. H=8m (see
[9.75m 3 /h / 4.5m] can be han-
pump catalogue). For this max-
dled by a Riotec 50-60 pump.
imum case, the following sys-
For the present example, invest-
tem constant is calculated for
ment costs for the circulator
the heating circuit:
pump are reduced as follows:
Q N, Systronic = 0.75 · Q N,conv = 0.75 · 13m 3 /h = 9.75m 3 /h
Equation 12
H N,Systronic = k heating circuit · Q2 N,Systronic = 0.0473 · 9.75m 2 = 4.5m
Equation 13
Pump
Fig. 17 Control unit of BOASystronic (Systrobox
Catalogue price 2005 [€]
Riotec 65 – 100
1,825.11
Riotec 50 – 60
1,223.20
Difference [€]
602.91
Table 02: Reduced investment costs for circulator pump
19
06.02.2006, 12:50:23 Uhr
10
Practical testing
10.3
Measurements
To verify the function of the
BOA-Systronic system, the
following quantities were
measured, among others. (Table 03)
Measurements were taken on
Heating circuit East
(3-way mixing configuration)
Heating circuit West
(BOA-Systronic)
External temperature
Volume flow rate at main feed manifold
Volume flow rate at main feed manifold
Differential pump pressure
Differential pump pressure
Electrical power input
Electrical power input
Tab. 03: Measured quantities
545 days in the period from
2000 to 2002. The measured
measuring period 2000 to
temperature of the heating
values were recorded at two-
2002. The diagram shows an
system is [(-12°C) – (+16°C)] =
minute intervals, resulting in
average external temperature of
28°C. The temperature differ-
711 values per day (24 hours),
approx. 10°C in the period
ence between the design point
from which the day mean
monitored. Depending on the
and the average temperature is
values were calculated for each
location, the heating circuits are
[(-12°C) – (+10°C)] = 22°C.
measured quantity.
selected for an external temper-
The ratio between both values
ature of approx. –12°C to –15°C.
is 22/28 = 0.79. This means
Regulations stipulate that the
that in the monitored period
building must be heated until
both heating circuits on average
the external temperature
only require about 21% of the
reaches approx. 16°C. The tem-
thermal output they were se-
The external temperatures
perature difference between the
lected for. This theory should
measured were plotted for the
design point and the switch-off
be confirmed by a comparison
10.4
External temperature [°C]
External temperature – Heidelberg test installation – Average temp. 10°C (approx)
35
30
25
20
15
10
5
0
-5
22. Oct 02
22. Sep 02
23. Aug 02
24. Jul 02
24. Jun 02
25. May 02
25. Apr 02
26. Mar 02
24. Feb 02
25. Jan 02
26. Dec 01
26. Nov 01
27. Oct 01
27. Sep 01
28. Aug 01
29. Jul 01
29. Jun 01
30. May 01
30. Apr 01
31. Mar 01
1. Mar 01
30. Jan 01
31. Dec 00
1. Dec 00
1. Nov 00
-10
Years
Fig. 18 External temperatures measured at the test installation in 2000 – 2002
20
06.02.2006, 12:50:25 Uhr
10
Practical testing
of the volume flow rates meas-
required volume flow rate Qnom
heating circuit by BOA-Systronic
ured, the differential pump
for the design point is calculat-
during the utilization period is
pressures and the pump power
ed as follows:
considerably smaller than the vol-
consumption of both systems.
Pth
Qnom =
10.5
Volume flow rates
1.163 · ∆ T
Equation 14
=
300
1.163 · 20
m 3 /h = 13m 3 /h.
The conventional, mixing-type
This value is confirmed by the
ume flow rate the conventional,
system must provide a thermal
measurements (Fig. 19). Irrespect-
mixing-type system provides to its
output Pth = 300 kW at the de-
ive of its degree of opening, the
heating circuit. Fig. 19 shows that
sign point. Based on a tempera-
three-way control valve of the
the measured nominal volume
ture differential ∆T = 20K, the
conventional, mixing-type system
flow rates supplied by the conven-
always supplies the nominal vol-
tional, mixing-type system do not
ume flow rate to the heating circuit
quite reach the theoretical, calcu-
(constant-flow system). BOA-
lated values. This is due to the
Systronic, by contrast, adjusts the
control function of the thermostat-
resulting volume flow rate in the
ic valves under the influence of
main feed circuit depending on the
external heat input to the heating
opening degree of the two control
circuit. The equation
valves and thus depending on the
ing controller. As expected, the
t2
water volume flow = ∫ Q(t) dt
t1
volume flow rate supplied to the
is used to calculate the amounts
control signal issued by the heat-
Volme flow rate [m3/h]
Volume flow rates – Heidelberg test installation – Savings by BOA-Systronic approx. 65%
16
14
12
10
8
5
4
2
22. Oct 02
22. Sep 02
23. Aug 02
24. Jul 02
24. Jun 02
25. May 02
25. Apr 02
26. Mar 02
24. Feb 02
25. Jan 02
26. Dec 01
26. Nov 01
27. Oct 01
27. Sep 01
28. Aug 01
29. Jul 01
29. Jun 01
30. May 01
30. Apr 01
31. Mar 01
1. Mar 01
30. Jan 01
31. Dec 00
1. Dec 00
1. Nov 00
0
Years
3-way configuration
BOA-Systronic
Fig. 19 Volume flow rates measured at the main feed manifold in 2000 – 2002
21
06.02.2006, 12:50:25 Uhr
10
Practical testing
of water (volume flow rates)
At identical thermal output,
pumped through the two heat-
BOA-Systronic was shown to
ing circuits, respectively. The
pump only 40 % of the water
mean values of the volume flow
volume through the heating cir-
rates measured in the two heat-
cuit, compared to the conven-
ing circuits are calculated.
tionally equipped heating circuit.
Measured Quantity
Volume flow rate (Q)
Heating circuit
3-way configuration
3
[m /h]
Mean value
Q Systronic /Q 3 - way configuration
BOA-Systronic
3
Unit
Ratio
[m /h]
11.2
3.2
0.29
Table 4: Analysis of volume flow rates in 2000-2002
10.6
Differential pressures
of the pumps
With BOA-Systronic, the pump
is operated on average at only
about 66% of the nominal
discharge head at design point.
Measured Quantity
Differential pressure (H)
Heating circuit
3-way configuration
Unit
[m]
Mean value
4.4
Ratio
H Systronic /H 3 - way configuration
BOA-Systronic
[m]
2.9
0.66
Table 5: Analysis of differential pump pressures in 2000 -2002
Pump differential pressures [mbar]
Pump differential pressures – Heidelberg test installation – Savings by BOA-Systronic approx. 37%
800
700
600
500
400
300
200
100
22. Oct 02
22. Sep 02
23. Aug 02
24. Jul 02
24. Jun 02
25. May 02
25. Apr 02
26. Mar 02
24. Feb 02
25. Jan 02
26. Dec 01
26. Nov 01
27. Oct 01
27. Sep 01
28. Aug 01
29. Jul 01
29. Jun 01
30. May 01
30. Apr 01
31. Mar 01
1. Mar 01
30. Jan 01
31. Dec 00
1. Dec 00
22
1. Nov 00
0
Years
3-way configuration
BOA-Systronic
Fig. 20 Differential pressures of the circulators measured in 2000 – 2002
22
06.02.2006, 12:50:26 Uhr
10
Practical testing
10.7
Pump input
power
The pump input power, and
heads, the pump draws much
thus its power consumption, is
less power from the electricity
proportional to the product of
grid. BOA-Systronic was shown
the discharge head and volume
to save approx. 70% in
flow rate. As BOA-Systronic
electrical energy.
operates the pump at reduced
volume flow rates and discharge
Measured quantity
Pump input power (P)
Heating circuit
3-way configuration
Unit
PSystronic /P3 - way configuration
BOA-Systronic
[W]
Mean value
Ratio
[W]
561
184
0.33
Table 6: Savings in pump power consumption
Pump input power [W]
Pump input power – Heidelberg test installation – Savings by BOA-Systronic approx. 70%
900
800
700
600
500
400
300
200
100
22. Oct 02
22. Sep 02
23. Aug 02
24. Jul 02
24. Jun 02
25. May 02
25. Apr 02
26. Mar 02
24. Feb 02
25. Jan 02
26. Dec 01
26. Nov 01
27. Oct 01
27. Sep 01
28. Aug 01
29. Jul 01
29. Jun 01
30. May 01
30. Apr 01
31. Mar 01
1. Mar 01
30. Jan 01
31. Dec 00
1. Dec 00
1. Nov 00
0
Years
3-way configuration
BOA-Systronic
Fig. 21 Pump power input in 2000 – 2002
Conclusion
In our example, both heating circuits on average require only 21% of the thermal
output at design point. By comparison, BOA - Systronic consumes only about 30 % of
the electricity required by the conventional set- up ( here : 3 - way mixing system) .
23
06.02.2006, 12:50:27 Uhr
11
Payback period for BOA - Systronic
11
Payback period
for BOA -Systronic
11.1
Control valve investment and energy
savings
valves and the pump as well
configuration, the differences
as automatic hydraulic bal-
depending on the nominal sys-
ancing at the main feed mani-
tem diameter of the main feed
fold.
circuit (table 07).
Items (1) to (5) can also be
In the present example, a main
planned and achieved in a con-
feed circuit with a thermal out-
ventional system by increasing
put of 300 kW was equipped
the temperature differential at
with BOA-Systronic of nominal
With BOA-Systronic, the nom-
design point. Items (6) and (7),
system diameter DN50, where-
inal diameter of the heating cir-
however, can only be realized
as a nominal diameter of DN65
cuit components can be smaller
with BOA-Systronic.
was selected for the convention-
than usual. This is due to the
al set-up of identical thermal
combined effect of increased
To compare the prices of the
temperature differential (differ-
two systems, the average price
ence between supply and return
for a conventional, mixing-type
A simulation (version 1.21) was
temperature) and reduced vol-
system of nominal diameter
used to estimate the energy
ume flow rates at design point,
DN65 was determined on the
costs incurred for the glandless
so that
basis of the catalogue prices
Riotec 50-100 pump during the
1. the main feed pipe is one
given by 5 competitors. The
heating period (table 10). Com-
mixing-type configuration com-
pared to the average price of a
prises the following compo-
mixing-type system, the invest-
main feed circuit are one
nents:
ment costs for BOA-Systronic
nominal diameter smaller
• 3-way control valve
would be approx. € 402 higher
• swing check valve in the mix-
in this case. If this extra price is
nominal diameter smaller
2. the shut-off valves in the
3. the strainers in the main
feed circuit are one nominal
diameter smaller
4. a smaller circulator pump
can be chosen
5. the measurement and control valves are one nominal
output (table 08).
ing line
deducted from the electricity
• balancing valve
savings realized per heating
The gross price of BOA-Sys-
period, investment in BOA-
tronic, by contrast, is somewhat
Systronic will pay back after
higher than the average price of
roughly one year.
a conventional mixing-type
diameter smaller
6. differential pressure controllers for balancing the heat-
Nominal
system diameter
ing circuits are not required
DN25 to DN50
7. commissioning costs are re-
DN65 to DN80
duced thanks to automatic
initialization of the control
Average extra price compared to
3-way mixing configuration in [%]
11 %
4%
DN100 to DN150
13 %
Tab. 07: Average extra prices for BOA-Systronic
Heating circuit
Unit
Value
Average gross price of 3-way mixing configuration, DN65 (prices of 2005)
€
1,673
Gross price of BOA-Systronic, DN50 (prices of 2005)
€
1,858
Gross price of LON module for Riotec pump, pre -initialized
€
217
Difference
+402
Tab. 08: Extra price for BOA-Systronic with Riotec pump (example: DN50)
24
06.02.2006, 12:50:27 Uhr
11
Heating circuit
Unit
Value
Difference
Average gross price of 3-way mixing configuration, DN65 (prices of 2005)
€
1,673
Gross price of BOA-Systronic, DN50 (prices of 2005)
€
1,858
Gross price of LON -module forRio - Eco pump, non-initialized
€
187
+372
Table 09: Extra price for BOA-Systronic with Rio-Eco pump (example: DN 50)
Cost factor
Unit
Value
Average price of electricity
€ /kWh
Difference
0.11
Average operating hours per heating period
h
6,800
Average efficiency η of Riotec circulator pump
%
35
Average pump power consumption/heating period; conv., mixing-type system DN65
kWh
5,000
Average pump power consumption/heating period; BOA-Systronic DN50
kWh
1,200
Average price of electricity/heating period; conv., mixing-type system DN65
€
548
Average price of electricity/heating period; BOA-Systronic DN50
€
131
-3,800
- 417
Table 10: Energy costs in fi rst year (example: DN 50)
11.2
Investment costs for
heating circuit with
Riotec pump
If the extra price for BOA-
present hourly rates (2005), this
Systronic is deducted from the
results in an additional € 45
reduced investment costs
saved.
(€ 1,059–€ 402), the investment
costs for the main feed circuit
Investment in BOA-Systronic
By utilizing all saving potentials
will be reduced to € 657 in this
would, therefore, pay back im-
offered by BOA-Systronic, the
case. In addition, automated
mediately, and the investment
investment costs of the present
commissioning further reduces
and commissioning costs for
heating circuit can be reduced
the commissioning costs per
the heating circuit would be re-
by € 1,059.
heating circuit by one hour. At
duced substantially.
Cost factor
Unit
Difference
(1)
Smaller nominal diameter of main feed pipe
€
-75
(2)
3 shut- off valves of smaller DN in main feed circuit
€
-123
(3)
1 strainer (standard mesh) of smaller DN in main feed circuit
€
-29
(4)
1 Riotec 50 - 60 circulator pump instead of Riotec 65 -100
€
- 602
Measurement and control valves one DN smaller (BOA-Systronic)
€
see above
€
-230
€
-1,059
(5)
(6) No differential pressure controller required (1 no. per heating circuit, 1.5 -inch)
Sum total of factors (1) to (6)
Tab. 11: Reduced investment costs for heating circuit with Riotec pump, example (prices 2005)
25
06.02.2006, 12:50:28 Uhr
11
11.3
Investment costs for
heating circuit with
Rio - Eco pump
If the extra price for BOA-Sys-
Investment in BOA-Systronic
tronic is deducted from the re-
would, therefore, pay back im-
duced investment costs (€ 933–
mediately, and the investment
€ 372), the investment costs for
and commissioning costs for
the main feed circuit are re-
the heating circuit would be
By utilizing all saving potentials
duced to € 561 in this case. In
reduced substantially.
offered by BOA-Systronic, the
addition, automated commis-
investment costs of the present
sioning reduces the commis-
heating circuit can be reduced
sioning costs per heating circuit
by € 933.
by one hour. At present hourly
(Table 12)
rates (2005), this saves an additional € 45.
Cost factor
Unit
Difference
(1)
Smaller nominal diameter of main feed pipe
€
-75
(2)
3 shut- off valves of smaller DN in main feed circuit
€
-123
(3)
1 strainer (standard mesh) of smaller DN in main feed circuit
€
-29
(4)
1 Rio - Eco 40 - 80 circulator pump instead of Riotec 65 -100
€
- 476
(5)
Measurement and control valves one DN smaller (BOA-Systronic)
€
see above
€
-230
€
-933
(6) No differential pressure controller required (1 no. per heating circuit, 1.5 -inch)
Sum total of factors (1) to (6)
Table 12: Reduced investment costs for heating circuit with Rio-Eco pump, example (prices 2005)
11.4
Total savings compari son Riotec / Rio - Eco
In the present example, the
Rio-Eco pump could be expected to pay back after approximately three years, compared to
the Riotec pump.
26
06.02.2006, 12:50:28 Uhr
11
Reduced investment costs for heating circuit (1) – (6) [€]
Extra price for BOA-Systronic [€]
-1,119
-34
-1,503
-933
372
Year 02
-455
-1,608
-48
Year 03
-455
-2,111
Year 04
-493
Year 05
Interest on savings (3% ) [€]
Savings plus interest [€]
Price of electricity [€ / kWh]
Pump operating hours [h]
-45
- 456
-1,062
-32
-1,094
0,11
6,800
-1,656
- 498
-1,592
- 48
-1,640
0.12
6,800
-63
-2,174
- 498
-2,138
- 64
-2,202
0.12
6,800
-2,667
-80
-2,747
-539
-2,741
- 82
-2,283
0.13
6,800
-493
-3,240
-97
-3,337
-539
-3,362
-101
-3,463
0.13
6,800
Year 06
-531
-3,868
-116
-3,984
-581
- 4,044
-121
- 4,165
0.14
6,800
Year 07
-531
-4,515
-135
-4,651
-581
- 4,746
-142
- 4,889
0.14
6,800
Year 08
-569
-5,220
-157
-5,376
- 622
-5,511
-165
-5,676
0.15
6,800
Year 09
-569
-5,945
-178
-6,124
- 622
- 6,298
-189
- 6,487
0.15
6,800
Year 10
-607
-6,731
-202
-6,933
- 664
-7,151
-215
-7,365
0.16
6,800
Year 11
-607
-7,540
-226
-7,766
- 664
- 8,029
-241
- 8,270
0.16
6,800
Year 12
-645
-8,411
-252
-8,663
-705
- 8,975
-269
-9,244
0.17
6,800
Year 13
-645
-9,308
-279
-9,588
-705
-9,949
-298
-10,248
0.17
6,800
Year 14
-682
-10,270
-308
-10,578
-747
-10,995
-330
-11,325
0.18
6,800
Year 15
-682
-11,260
-338
-11,597
-747
-12,072
-362
-12,434
0.18
6,800
Year 16
-720
-12,317
-370
-12,687
-788
-13,222
-397
-13,619
0.19
6,800
Year 17
-720
-13,407
-402
-13,809
-788
-14,407
- 432
-14,839
0.19
6,800
Year 18
-758
-14,567
-437
-15,004
- 830
-15,669
- 470
-16,139
0.20
6,800
Year 19
-758
-15,762
-473
-16,235
- 830
-16,969
-509
-17,478
0.20
6,800
Year 20
-758
-16,993
-510
-17,503
- 830
-18,308
-549
-18,857
0.20
6,800
Reduced operating costs [€]
Savings [€]
-45
Reduced operating costs [€]
402
Reduced commissioning costs for heating circuit [€]
Reduced commissioning costs for heating circuit [€]
-417
Extra price for BOA-Systronic [€]
Savings plus interest [€]
-1,059
Interest on savings (3% ) [€]
Reduced investment costs for heating circuit (1) – (6) [€]
Year 01
Rio - Eco (η =50%)
Savings [€]
Period
Riotec (η =35%)
Table 13: Outline of costs expected in 20 years of useful life
27
06.02.2006, 12:50:29 Uhr
11
0
-1000
-2000
-3000
-4000
-5000
-6000
-7000
Savings [€]
-8000
-9000
-10.000
-11.000
-12.000
-13.000
-14.000
-15.000
-16.000
-17.000
-18.000
-19.000
-20.000
-21.000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Years [a]
Riotec pump: Savings plus interest (parallel shift)
Riotec pump: Savings plus interest (slope modification)
Rio-Eco pump: Savings plus interest (parallel shift)
Rio-Eco pump: Savings plus interest (slope modification)
Fig. 22 Savings realized by Riotec and Rio-Eco pumps with slope modifi cation and parallel shift (example)
Period [a]
5
10
15
20
Reduced costs
Unit
Investment and commissioning
€
Riotec
-702
Rio - Eco
- 606
Difference
96
Pump operation
€
-2,313
-2,530
-217
Interest on savings (3 %)
€
-322
-327
-4
Total
€
-3,337
-3,463
-125
Annual savings
€
- 667
- 693
-25
€
-702
- 606
96
Pump operation
€
-5,120
-5,600
- 480
€
-1,111
-1,159
- 49
Total
€
- 6,933
-7,365
- 433
Annual savings
€
- 693
-737
- 43
€
-702
- 606
-96
Pump operation
€
- 8,381
-9,168
-787
€
-2,514
-2,660
-146
Total
€
-11,597
-12,434
- 837
Annual savings
€
-773
- 829
-56
€
-702
- 606
-96
Pump operation
€
-12,095
-13,234
-1,139
€
- 4,706
-5,017
-311
Total
€
-17,503
-18,857
-1,354
Annual savings
€
- 875
-943
- 68
Tab. 14: Total savings
28
06.02.2006, 12:50:29 Uhr
12
References
12
References
Since being released for sale in
2003, BOA-Systronic has been
in operation in many heating
systems in public and industrial
buildings throughout Germany.
The photo below shows three
heating circuits equipped with
BOA-Systronic systems of
nominal diameter DN32.
Fig. 23 Heating circuits with BOA-Systronic DN32
29
06.02.2006, 12:50:30 Uhr
13
Conclusion
13
Conclusion
pressure control valves for bal-
tions are prevented, and flow
ancing the heating circuits are
noises at the consumer points
not required. They can be re-
are avoided.
BOA-Systronic reduces operat-
placed by balancing valves,
BOA-Systronic is gentle on the
ing costs.
which are less expensive. Even
environment.
in heating circuits already
An analysis of load profiles in
equipped with a LON-compat-
Electricity is something you
heating systems revealed that
ible variable speed pump, in-
cannot produce and store for
heating circuits operate under
vestment in BOA-Systronic will
later use, but it must be avail-
part-load conditions for more
pay back in less than two years.
able at the exact moment when
it is needed. Burning fossil fuels
than 95% of their operating
time. From this finding, it is
BOA-Systronic reduces the
produces CO2 emissions of
safe to conclude that in conven-
commissioning costs for the
roughly 0.53 kg per 1 kWh of
tional mixing or injection-type
heating circuit.
electrical energy produced.
Thanks to the drastic reduction
systems cold return water is being circulated through the heat-
The circulator pump and the
in power consumption, BOA-
ing circuit most of the time.
control valves are initialized
Systronic therefore makes a
BOA-Systronic, by contrast,
automatically. Static balancing
positive contribution to envir-
provides only the volume flow
at the main feed manifold is
onmental protection.
actually required and can thus
performed automatically by the
save an average of 70% electri-
pump. The hydraulic operation
city costs for the circulator pump
of the heating circuit is opti-
over the heating period, which
mized. The system immediately
– depending on the thermal
detects any air in the piping and
output of the heating circuit –
thus prevents unnecessary com-
may amount to several hun-
missioning work. Altogether,
dreds of Euros in electricity
the costs for heating circuit
savings per year.
commissioning are reduced.
BOA-Systronic reduces the in-
BOA-Systronic offers increased
vestment costs for the heating
comfort of use.
circuit.
The hydraulic operation of the
In new or replacement installa-
heating circuit is optimized
tions, the investment costs for
thanks to substantially reduced
the main feed circuit can be re-
discharge heads and volume
duced without modifying the
flow rates. Excessive discharge
original planning. Differential
heads under part-load condi-
30
06.02.2006, 12:50:32 Uhr
List of figures
Fig. 1
Hydraulics schematics of BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Fig. 2
Comparison of systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Fig. 3
BOA-Systronic components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Fig. 4
Volume flow rates of 3-way valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fig. 5
Reduced volume flow rates of BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Fig. 6
Circulator pump heads (example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Fig. 7
Heating circuit with branch circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Fig. 8
Excess circulator pump heads (example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Fig. 9
Two-boiler system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Fig. 10
Return manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Fig. 11
Control cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fig. 12
Heating controllers for West and East wings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fig. 13
Main feed manifold, West and East wings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fig. 14
Main feed circuit with BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Fig. 15
Main control valve of BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Fig. 16
Mixing valve of BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Fig. 17
Control unit of BOA-Systronic (Systrobox) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Fig. 18
External temperatures measured at the test installation in 2000 – 2002 . . . . . . . . . . . . . . . 20
Fig. 19
Volume flow rates measured at the main feed manifold in 2000 – 2002 . . . . . . . . . . . . . . . 21
Fig. 20
Differential pressure of the circulators, measured in 2000 – 2002 . . . . . . . . . . . . . . . . . . . . 22
Fig. 21
Pump power input in 2000 – 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Fig. 22
Savings realized by Riotec and Rio-Eco pumps with slope modification and parallel shift . . 29
Fig. 23
Heating circuits with BOA-Systronic DN32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
List of tables
Table 1
Performance data of main feed circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 2
Reduced investment costs for circulator pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 3
Measured quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 4
Analysis of volume flow rates in 2000 – 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 5
Analysis of differential pump pressures in 2000 – 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 6
Savings in pump power consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 7
Average extra prices for BOA-Systronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 8
Extra price for BOA-Systronic with Riotec pump (example: DN50) . . . . . . . . . . . . . . . . . . 24
Table 9
Extra price for BOA-Systronic with Rio-Eco pump (example: DN 50) . . . . . . . . . . . . . . . . 25
Table 10 Energy costs in first year (example: DN50) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 11 Reduced investment costs for heating circuit with Riotec pump, example (prices 2005) . . . 25
Table 12 Reduced investment costs for heating circuit with Rio-Eco pump, example (prices 2005) . . 26
Table 13 Outline of costs expected in 20 years of useful life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 14 Total savings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
31
06.02.2006, 12:50:32 Uhr
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Water Hammer
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06.02.2006, 12:50:48 Uhr
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BOA-Systronic 2 MB

Transcription

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