High Efficient SCR for SCR only Applications for NRMM

Transcription

High Efficient SCR for SCR only
Applications for NRMM
Rolf Brück, Emitec GmbH
1
Agenda
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

Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
Heavy Duty /NRMM – Emission Standards (ETC) & Technology Shift of Priorities
Engine Technology
EU VI; NRMM >130 kW Stage 3 B
PM [mg/kWh]
60
NRMM EU
Stage IV
30
EU V
EU IV
NRMM EU IIIB
SCR 80 %
EU VI
0
NRMM
Stage IIIB
(2012)
SCR 80 %
1
2
3
4
NOx [g/kWh]
6
Engine Technology
PM [mg/kWh]
60
NRMM EU
Stage IV
30
EU V
EU IV
NRMM EU IIIB
SCR 80 %
NRMM
Stage IIIB
(2012)
EU VI
0
1
2
3
4
NOx [g/kWh]
6
Engine Technology
PM [mg/kWh]
60
NRMM EU
Stage IV
30
EU V
EU IV
NRMM EU IIIB
SCR >92 -95 %
EU VI
0
1
2
3
4
NOx [g/kWh]
6
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Introduction
SCR Dosing System
Conclusion
Challenges and demands for SCR- Emission control
technologies across various applications
Thermodynamic
Challenges
Heat up during cold start
low temperature condition
Start of AdBlue Injection
AdBlue-Decomposition
Thermodynamic
Challenges
NH3/ NOx Uniformity
SCR “Light-Off”
SCR Conversion
Limitation SCR Kinetic
Limitation NH3/ NOx
Limitation NH3 storage
Thermodynamic
Challenges
Priorities
PC / LD / MD
NEDC
RDE /(NTE)
FTP
US06
JC08
Non-Road
NRMM
NRSC
NRTC cold
NRTC.Warm
HD On-Road
Steady State
ETC
WHTC cold
WHTC warm
FTP
JE05
NH3/ NOx Uniformity
SCR “Light-Off”
SCR Conversion
Limitation NH3/ NOx
Thermodynamic
Challenges
Priorities
PC / LD / MD
NEDC
RDE /(NTE)
FTP
++
+++
+
++
+
Non-Road
NRMM
++
+
+
++
+
++
+
+
++
ETC
++
WHTC warm
>80
++
>80
>80
++
>80
>95
++
++
++
> 80
+
++
+
> 95
Steady State
WHTC cold
++
++
NRTC.Warm
HD On-Road
++
NRSC
NRTC cold
+
NH3/ NOx Uniformity
SCR “Light-Off”
US06
JC08
++
+
>93
>93
+
++
++
++
++
++
++
>70
++
++
++
++
>80
FTP
+
+
++
++
++
>80
JE05
++
+
++
++
++
>80
SCR Conversion
Limitation of NH3/ NOx
Fundamantal Steps for AdBlue Decomposition
and Technology for System Optimization
AdBlue droplet interaction on surface
Adblue® droplet
penetration on surface
steps from AdBlue towards ammonia:
evaporation & thermolysis
1. + 2. reaction steps
1. Step:
evaporation of Water:
{(NH2)2CO •7H2O}fl
{(NH2)2CO}fl + 7 H2O
2. Step:
thermolysis of Urea:
{(NH2)2CO}fl
HNCO + NH3
3. Step:
hydrolysis of isocyanic acid:
HNCO + H2O
CO2 + NH3
Technologies for Optimization:
 Hydrolysis:
 NH3 – Distribution:
Usage of Hydrolysis Catalyst / Mixer
Optimization of Mixing pipe and mixing
design
11
NOx- SCR-Efficiency as Function of NO2-Ratio
Reaktionen bei der NOX – Reduktion durch SCR:
Standard SCR- Reaction with NO:
4 NO + O2 + 4 NH3
4 N2 + 6 H2O
“fast“ SCR-Reaction with NO+NO2:
2 NO2 + 2 NO + 4 NH3
4 N2 + 6 H2O
6
100
90
80
70
60
50
40
30
20
10
0
NO2 / NO
50% / 50%
Temperature
Range at low
load operation
NO
5
NO2 / NO
0% / 100%
NO, NO2 [g/kWh]
NOx Conversion Rate [%]
Emissions during ETC
NO2
4
NO
3
2
0
0
100
200
300
400
- 30%
NO2
1
NO2
NO2
Engine Out behind DOC behind SCR
Temperature [°C]
12
Calculated NOx-Reduction and NH3 Slip as Function of
NH3-Uniformity and AdBlue-Dosing Rate
NOx-Reduction
100
Alpha
Alpha
Alpha
Alpha
95
90
85
80
75
70
0,88 0,9 0,92 0,94 0,96 0,98
NH3-Uniformity
1
=
=
=
=
1.00
0.95
0.90
0.80
Calculated NOx-Reduction and NH3 Slip as Function of
NH3-Uniformity and AdBlue-Dosing Rate
NOx-Reduction
NH3- Slip
100
60
95
50
90
40
85
30
80
20
75
10
70
0,88 0,9 0,92 0,94 0,96 0,98
NH3-Uniformity
1
0
0,88
Alpha
Alpha
Alpha
Alpha
0,9
=
=
=
=
1.00
0.95
0.90
0.80
0,92 0,94 0,96 0,98
NH3-Uniformity
DeNOx Performance as Function of NH3- Uniformity
100
NOx = 200ppm
95
NOx-Conversion [%]
short tube
Long tube
DOC
AdBlue
SCR
90
Short tube
long tube
85
short tube
long tube
DOC
AdBlue
80
0
5
10
15
20
25
30
NH3-Slip
SCR
Influence of System Design on NH3-Uniformity
and DeNOx- Performance
120
S-tube
NH3-slip [ppm]
100
straight tube
80
60
straight tube
40
20
0
70
T= 410°C
NOx = 350 ppm
SV.SCR = 58.000 1/hr
80
90
100
NOx-conversion [%]
S-tube
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Introduction
SCR Dosing System
Conclusion
Emitec SCR-Dosing system Gen III
Customized Tank for the
application
In Tank SCRDosing system
Gen III
Emitec Gen III System Description
All in One Integration
Suction lance
Temperature sensor
Urea filter
Level sensor
Tank heater
Heated suction line
External DCU
Quality sensor
Installation cost:
Electrical harness
Fixing devices
Lines connections
Emitec Dosing System Gen III; OutsideView
Ringfilter
Connector to
Injector
Electrical
Connector
Emitec Dosing System Gen III; InsideView
PTC Heater
Pressure Control
Valve
Pump
Level-/Quality
Sensor
Electronic
Pressure Sensor
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Introduction
SCR Dosing System
Conclusion
Motor Drehmoment
Torque
engine torque
Thermal Challenges for AdBlue Injection within Engine Map
+ static mixer
•
•
•
fast start of dosing
excellent evaporation of droplets
low risk for depositions
+ Hydrolysis Catalyst
low temperature area
Motor Drehzahl
Engine
Speed
engine speed
NOx Efficiency with Optimised Airless Dosing Layout
Summary of Sweep Test
100
98
NOx Efficiency
96
94
92
90
88
86
0,85
0,9
0,95
Alpha (-)
1
1,05
Test conditions:

constant speed / torque
•
constant temperature and massflow and exhaust gas
condition
•
exhaust gas 714 kg/h, T = 420 °C, NOx = 543 ppm;
NO2/NOx = 0,27
theoretical AdBlue® demand for (alpha = 1) = 1100 ml / h


setup with Fe-Zeolithe catalyst [Ø242 x (110 + 110)]  10,1 ltr
dosing rate 1000 ml / h  1200 ml/h (alpha = 0,9 ... 1,1)
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Introduction
SCR Dosing System
Conclusion
Compact SCR System for Heavy Duty and Non Road
Mobile Machineries
DOC
LS/PE-Metalit®
Mobile Machineries
DOC
LS/PE-Metalit®
AdBlue-Injector
Reductant Delivery Unit (Urea Injector)
- Robust design
based on mass production
- gasoline injector
- Spray pattern can
adapted to application
Water Cooling for highest
Off Road demands
Mobile Machineries
Mixing Element /
Hydrolysis Catalyst
DOC
LS/PE-Metalit®
AdBlue-Injector
Comparison of a Mixer / Hydrolysis Catalyst regarding
Deposits at Low Temperature AdBlue Injection
Variant 1 with
Mixing Element
Variant 2 with
Hydrolysis Catalyst
N= 1200 1/min; Md = 215 Nm
Exhaust Mass: 326 kg/h; T = 230°C
AdBlue-Dosage = 560 g/h, α = 0.8
Mobile Machineries
SCR- Catalyst
LS-Metalit®
Mixing Element /
Hydrolysis Catalyst
DOC
LS/PE-Metalit®
AdBlue-Injector
Mobile Machineries, Demonstrator
close coupled
DOC + 1. stage SCR
2.Stage
SCR
SCR only System Layout
1. Stufe
DOC
(2,2 ltr)
static mixer
2. Stufe
SCR 2
(4,0 ltr)
SCR 1
(6,5 ltr)
Motor
close coupled
NOx
NOx
T
T
NOx
Flow / NH3 Distribution @ Close Coupled SCR Catalyst
UI = 0,96
0
Total velocity
[m/s]
10
Cumulated NOx Emissions at alfa = 1 during NRTC
3 0. 0
Acumulated AdBlue [g]
6 0. 0
30 0
NOx engine out
AdBlue-Mass
20 0
10 0
0. 0
0
Acumulated NOx [g]
Acumulated NOx [g]
9 0. 0
NOx after 1. Stage
NOx Tailpipe
5
0
0
2 00
400
60 0
time [s]
80 0
1 000
120 0
14 00
Accumulated NOx Emissionen after 1st and 2nd SCR Stage
during NRTC Test
Acumulated NOx [g]
90
60
1. SCR Stage
91,1 %
30
2.SCR Stage
Acumulated NOx [g]
0
94,6 %
post SCR 2
3
0
0
20 0
40 0
600
time [s]
800
1 000
1 200
14 00
Total NOx Reduction and NH3 Slip during NRTC Test
Acumulated Nox [g]
90
60
SCRa
30
NH3 [ppm]
0
94,6 %
1 00
0
0
20 0
400
6 00
time [s]
80 0
100 0
1 200
14 00
Tailpipe
NH3 concentration
(no NH3 slip catalyst)

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

Introduction
SCR Dosing System
Conclusion
Splitting of the Functions: Hydrolysis and NOx-Reduction
Hydrolysis-Function
DEF (fluid)
[(NH2)2CO•7H
2O]fl
gaseous
NH3 + CO2 + H2O
H-Kat H-Kat
MX MX
Red. Cat Red. Cat Red. Cat
LS/PE LS
LS
Slip-Cat
One System Layout for several Engines and Applications
D 934
D 936
D 856
2 Sizes
of exhaust systems
LPS
D 9508
HPS
~ 50
Applications
1 Pump
1 Injector
LTM
Ober- / Unterwagen
LTR
LR
LB
LRB
LRS
HS
LHM
Rolf Brück, Emitec GmbH
41

High Efficient SCR for SCR only Applications for NRMM

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