1
Simulation andOptimization of DPF andSCR Systems
Roland WankerJohann C. Wurzenberger
CLEERS, Dearborn, May 2006 | Page 2
Contents
IntroductionModel Status
Model Integration
Model Application
Aftertreatment Simulation Workflow
Simulation ExamplesSCR System Optimization
DPF System Optimization
Summary
2
CLEERS, Dearborn, May 2006 | Page 3
Aftertreatment Simulation Strategy, I
Concepts for Emission Control SystemsDieselGasoline, ...
ComponentsCatalystsDPFsUrea/Diesel Injection, ...
Targets for OptimizationUniformity of Flow, ConcentrationsCompleteness of DPF RegenerationCycle EmissionsHeat-UpECU Calibration, ...
Variety in:
Integration of Models into a Variety of Simulation
Tools
Need for:
Pre-Defined Models
Ready-to Use Chemistry forCatalysts and DPFs
Flexibility of Models
to Define any Reaction ModelAccording to Customer Specific
Needs
CLEERS, Dearborn, May 2006 | Page 4
Aftertreatment Simulation Strategy, IIIntegration
BOOST 1D Aftertreatment
CRUISE (using BOOST 1D as dll)
BOOST 1D s-function in Matlab/Simulink
FIRE 2D/3D
Identical physical and chemical models
ApplicationFlexibility
Diesel Oxidation Catalyst (DOC)
Diesel Particulate Filter (DPF, CSF)
Selective Catalytic Reduction (SCR)
Three Way CatalystDedicated kinetic models for each specific application
Use BOOST 1D Aftertreatment as Platform
User Coding Interface allows 100% Access to all FeaturesCustomer’s proprietary kinetic models
3
CLEERS, Dearborn, May 2006 | Page 5
BOOST 1D Aftertreatment1D, fast, robust
Pre-defined reaction models available
Connected to iSIGHT for parameter identification
Component and system level simulations andoptimization
Analysis of reaction chemistry
Prediction of mode emissions
Starting point for any aftertreatment simulation activity
Model Integration, I
CLEERS, Dearborn, May 2006 | Page 6
FIRE 2D/3D Aftertreatment3D, very detailed
Pre-defined reaction models available
Pre-calibrated model from BOOST can be used
➨ Uniformity optimization(e.g. of species, temperature or mass flow)
➨ System optimization(e.g. spray, homogeneous reactions, DOC, SCR,DPF)
➨ CFD - FEM coupling(e.g. thermal stress during regeneration of a DPF)
Model Integration, II
4
CLEERS, Dearborn, May 2006 | Page 7
Model Integration, III
CRUISE AftertreatmentPre-calibrated model from BOOST can be used
➨ Investigate influence of different vehicles on catalystand DPF performance (and vice-versa)
Matlab/Simulink s-FunctionBOOST 1D aftertreatment connects to the wholeworld of MATLAB/SIMULINK
CLEERS, Dearborn, May 2006 | Page 8
CatalystDOC (TWC): Heat-Up during Cold Start
DOC (TWC): Flow Distribution, and Mode Emissions
DOC: NO <--> NO2 Conversion
SCR: System Configuration (HSO, ...)
SCR: Injection of Urea, Evaporation and Mixing
DPF❧ Loading: Soot Distribution and Pressure Drop
❧ Regeneration: Duration, Completeness and ThermalStresses
Exhaust System❧ Losses to Ambient
❧ Heat-Up of Pipes, Insulation Material, ...
Application, Optimization Targets
5
CLEERS, Dearborn, May 2006 | Page 9
Contents
IntroductionModel Status
Model Integration
Model Application
Aftertreatment Simulation Workflow
Simulation ExamplesSCR System Optimization
DPF System Optimization
Summary
CLEERS, Dearborn, May 2006 | Page 10
Aftertreatment Workflow Concept
End
User-DefinedVariation
Parameter
Start
User-DefinedObjective
(i.e. based onexperimental
data)
Yes/No
Model
Solver
OptimizationTool
ParameterVariation
Post-ProcessorCheck Objective
Step 1:
Parameter Identification
VehicleComponent/
System LevelComponent/System Level
Step 2:
Optim
ization
Matlab/Simulink
Vehicle Simulation3D Simulation1D Simulation
6
CLEERS, Dearborn, May 2006 | Page 11
Comparison of Experimental Data with Guessed and Tuned Kinetic Parameters
DPF Regeneration100 BOOST Runs iniSIGHT v7.1
Oxi-cat Light-off840 BOOST Runs iniSIGHT v7.1
Step 1, Parameter Identification
CLEERS, Dearborn, May 2006 | Page 12
Step 2, System Optimization
CRT-System,
30 NEDCs
DOC
DPFFlow
Heat Produced byBurning of Soot
Exhaust GasLineDOC and DPF
7
CLEERS, Dearborn, May 2006 | Page 13
Headline
IntroductionModel Status
Model Integration
Model Application
Aftertreatment Simulation Workflow
Simulation ExamplesSCR System Optimization
DPF System Optimization
Summary
CLEERS, Dearborn, May 2006 | Page 14
V-HSO System
Pre (Vor)-Catalyst
Hydrolysis, SCR and Oxidation Catalyst
8
CLEERS, Dearborn, May 2006 | Page 15
V-HSO System
Pre (Vor)-Catalyst
Hydrolysis, SCR and Oxidation CatalystSAE-2005-01-0948: (Wurzenberger and Wanker, AVL)
steady-state kinetic model validation
transient kinetic model validation
component level simulation
system level simulation
SAE-2006-01-0643: (Birkhold et al., BOSCH)
urea spray model validation
wallfilm model validation
evaporation and thermolysis reaction model validation
CLEERS, Dearborn, May 2006 | Page 16
Rate Equations
Steady-State, Eley-Rideal Transient, Temkin-Type
Hydrolysis Section Hydrolysis Section
SCR Section SCR Section
Oxidation Section Oxidation Section
9
CLEERS, Dearborn, May 2006 | Page 17
HSO SCR Catalyst, Steady-Approach3 Different Reaction Sections
1 Hydrolysis Reaction for HCNO
3 SCR Reactions of Eley-Rideal Type
2 Oxidation Reactions for NH3
1 Reversible Oxidation Reaction for NO
HCNO
NH3 NOx
SCR, Pre-Defined Kinetic Models, “Steady”
SAE 2005-01-0948,Wurzenberger, Wanker
CLEERS, Dearborn, May 2006 | Page 18
HSO SCR Catalyst, Transient Approach3 Different Reaction Sections
1 Hydrolysis Reaction for HCNO
2 Adsorption/Desorption Reactions for NH3
3 Transient SCR Reactions
2 Oxidation Reactions for NH3 (transient/steady)
1 Reversible Oxidation Reaction for NO
SCR, Pre-Defined Kinetic Models “Transient”
SAE 2005-01-0948, Wurzenberger, Wanker Catalysis Today (60), 2000, Nova et al.
10
CLEERS, Dearborn, May 2006 | Page 19
SCR, Pre-Oxidation Catalyst
SAE-2000-01-189, Gieshoff et.al, Degussa-Hüls AG
Light-Off for DifferentConverters Sizes
Light-Off, Comparisonwith Measurement
CLEERS, Dearborn, May 2006 | Page 20
SCR, Light-Off Simulation
SAE-2000-01-188, Chandler et al., Johnson Matthey
Light-Off, Comparison with Measurement
SAE-2005-01-948, Wurzenberger and Wanker, AVL
11
CLEERS, Dearborn, May 2006 | Page 21
SCR, System Simulation, DOC and SCR
SAE-2000-01-188, Chandler et.al, Johnson Matthey
Light-Off for Different SCR and Pre-Catalyst Sizes
CLEERS, Dearborn, May 2006 | Page 22
SCR, Urea Injection and 3D Flow
Urea Injection
Evaporation(Dukovicz Model)
Homogeneous GasPhase Reactions(Chemkin Interface)
HSO Converter Model,with Kinetic Parameterstuned in 1D
SAE-2005-01-948, Wurzenberger and Wanker, AVL
12
CLEERS, Dearborn, May 2006 | Page 23
SCR, 3D Species Distribution
H S O
HNCO, NH3, NO and NO2
NH3
NO
NO2NH3
HNCO
CLEERS, Dearborn, May 2006 | Page 24
Contents
IntroductionModel Status
Model Integration
Model Application
Aftertreatment Simulation Workflow
Simulation ExamplesSCR System Optimization
DPF System OptimizationLoading
Parameter Identification
System Simulation
Summary
13
CLEERS, Dearborn, May 2006 | Page 25
xx
LL
00
xx LL
VV22 (x) (x)
VV11 (x) (x) VVww (x) (x)
2.0
1.5
0.0 0.2 0.4 0.6 0.8 1.0
V1 (x)V2 (x)
Vw (x)
VelocitiesVelocities
LLxx
Soot, Ash layer
00
Ws (x)
1.0
0.5
Sketch of a DPFSketch of a DPF
DPF Flow Model
CLEERS, Dearborn, May 2006 | Page 26
DPF Model Features
Geometrysquare channelocto-square, ...
MaterialCordieriteSiCDura Trap AT,...
Soot Filtration ModelDepth FiltrationCake Filtration
Ash ModelRegeneration Model
Bare TrapCSFCatalytic Wall Reactions
SAE 2004-01-1132, Peters et al., AVL
14
CLEERS, Dearborn, May 2006 | Page 27
9.0 g/l
5 mm slices
Integration of pixels in all slices: 2D plot
Diesel Particulate FilterDPF Loading / Experiment
Computer Tomography
CLEERS, Dearborn, May 2006 | Page 28
0 50 100 150 200 250length z – mm
0.00
0.06
0.08
0.10
0.12
0.14
0.02
0.04
Soo
t lay
er h
eigh
t –
mm
BOOST 4,5 g/l
BOOST 9 g/l
BOOST 0,25 g/l
Computer Tomography 9 g/l
Diesel Particulate FilterDPF Loading / Validation
15
CLEERS, Dearborn, May 2006 | Page 29
Comparison of Experimental Data With Guessed and Optimized KineticParameters
~100 1D Simulation Runs using iSIGHT v7.1
Diesel Particulate FilterRegeneration analysis: Parameter Identification
CLEERS, Dearborn, May 2006 | Page 30
FIRE 3D: Diesel Exhaust Gas LineDPF Regeneration (post-injection)
Cat
DPF Flow
Heat Produced byBurning of Soot Heat Produced by
Oxidation of CO, HC,...
16
CLEERS, Dearborn, May 2006 | Page 31
Soot Mass Monolith Temperature
Wall Velocity O2 Mass Fraction
FIRE 3D: Diesel Exhaust Gas LineDPF Regeneration (post-injection)
CLEERS, Dearborn, May 2006 | Page 32
DPF Regeneration(Movie)
17
CLEERS, Dearborn, May 2006 | Page 33
DPF Regeneration, Gas Temperature Front(Movie)
CLEERS, Dearborn, May 2006 | Page 34
Conclusions and Outlook
Validated models for Catalysts and DPF available
DOC, TWC, SCR, ...
DPF, CSF, ...
Integrated Solution for Emissions ControlsSystem Optimization
1D: BOOST
2D/3D: FIRE
Vehicle: CRUISE
MATLAB Interface
Current activities
System level optimization
Integrate simulation into the development andapplication process