Analytical Tool Development for Aftertreatment Sub-Systems Integration B. Bolton, A. Fan, K. Goney, Z. Pavlova-MacKinnon, K. Sisken, H. Zhang Detroit Diesel Corporation
Engine and Sub-System Integration Strategy Outline Aftertreatment Model Development Strategy Model Applications for System Integration and Control Strategy Development Conclusions 2
System Development Methodology Control model Engine model Vehicle Integration Simulation Steady State Modal Development Urea Injector SCR Catalyst CSF Transient Dyno Development 3
Aftertreatment Model Philosophy Plug & Play» Simulink and Fortran Based Models» Common Framework» Can Be Combined Freely Variable Resolution - Adaptable» Prime Path A.T. Models are 1D» 0D and 3D Also Developed Common Framework» Sub-Models for Flow Chemical Kinetics Thermal Modeling Storage 4
Engine» Mapped Data» Mean Value (MV) Model» Cycle Simulation» Multi-Dimensional Models Vehicle Model» Simple» Complex Aftertreatment Models» DPF» SCR» LNT» DOC DDC s Tool Box Description 5
Individual Models Have Been Extensively Validated NO mass flow rate (kg/s) 1.6E-05 1.4E-05 1.2E-05 1.0E-05 8.0E-06 6.0E-06 4.0E-06 2.0E-06 0.0E+00 0 100 200 300 400 500 600 700 P(kPa) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 SCR Experimental engine out NO flow Experimental tailpipe NO flow Simulated tailpipe NO flow Time (s) DPF Numerical results Experimental results 0 0 0.25 0.5 0.75 1 1.25 1.5 Time(hour) NOx mass flow rate (kg/s) 4.0E-05 3.5E-05 3.0E-05 2.5E-05 2.0E-05 1.5E-05 1.0E-05 5.0E-06 0.0E+00 HC Emissions (kg/s) 3.0E-05 2.5E-05 2.0E-05 1.5E-05 1.0E-05 5.0E-06 0.0E+00 6 NOx after NOx before Simulated NOx 0 50 100 150 200 time (s) DOC LNT Pre DOC HC (kg/s) Post DOC HC (kg/s) Post DOC HC Simulation 0 100 200 300 400 500 600 time (s)
Outline Engine System Integration Strategy Aftertreatment Model Development Strategy Model Applications to System Integration and Control Strategy Development Conclusions 7
Integrated Emissions Reduction Roadmap Light Truck / SUV Platform Particulates (g/mile) 0.11 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.00 Engine Controls Strategy Advances in CLEAN Combustion Engine Controls Strategy Integrated with Aftertreatment Bin 6 Bin 5 Bin 7 Bin 8 Bin 9 Tier 2 Bin 10 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 NOx (g/mile) 8
Integrated Emissions Reduction Roadmap Light Truck / SUV Platform Particulates (g/mile) 0.11 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.00 Engine Controls Strategy Advances in CLEAN Combustion Engine Controls Strategy Integrated with Aftertreatment Bin 6 Bin 5 Bin 7 Bin 8 Bin 9 Tier 2 Bin 10 Engine Out Tier 2 Bin 10 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 NOx (g/mile) 9
Integrated Emissions Reduction Roadmap Light Truck / SUV Platform Particulates (g/mile) 0.11 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.00 Engine Controls Strategy Advances in CLEAN Combustion Engine Controls Strategy Integrated with Aftertreatment Bin 6 Bin 5 Bin 7 Bin 8 Bin 9 Tier 2 Bin 10 Tailpipe Out Tier 2 Bin 3 41% Fuel Economy Benefit Compared to Gasoline Baseline No NH 3 Slip Near Tier 2 Bin 9 Without Any Active NOx Aftertreatment 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 NOx (g/mile) 10
NOx Reduction Via Combustion and Aftertreatment Development Light Truck / SUV Platform 11
NOx Reduction Via Combustion and Aftertreatment Development Light Truck / SUV Platform 12
NOx Reduction Via Combustion and Aftertreatment Development Light Truck / SUV Platform 13
NOx Reduction Via Combustion and Aftertreatment Development Light Truck / SUV Platform 14
Urea Injection Mixing and Spray Development 15
Before Optimization Urea Injection Control Issue Hole-to-Hole Flow Rate Variation After Optimization 2 1 2 1 8 1 2 8 1 2 7 0 3 7 0 3 6 4 6 4 5 190 g/h 280 g/h 470 g/h 663 g/h 925 g/h 1700 g/h 5 16
3D CFD for NH3 Distribution Baseline Non-Uniform Injection Modified Uniform Injection 17
Urea Injection Control Strategy Development 18
Urea Control Strategies over Hot 505 Transient Cycle Using 1D SCR Model NOx Emissions (kg/s) 1.8E-05 1.6E-05 1.4E-05 1.2E-05 1.0E-05 8.0E-06 6.0E-06 4.0E-06 2.0E-06 0.0E+00 NOx In NOx Out (Baseline) NOx Out (Control X) NOx out (Control Y) Cycle Averaged NH3 Slip: Baseline: 1.0 ppm Control X: 2.9 ppm Control Y: 10.3 ppm 0 50 100 150 200 250 300 350 400 450 500 550 Time (s) 19
Urea Injection Control Strategies on SCR Performance for a Hot 505 Cycle Using 1D SCR Model 100 90 NOx Reduction Rate (%) 80 70 60 50 Optimization Region of Interest 40 0 20 40 60 80 100 120 NH3 Slip (ppm) 20
System Integration Experimental Validation Urea Injection Control Strategy Development 21
Technical Challenges and Issues Reduce AT System Complexity» Require Multiple AT Model Integrations Model Fidelity when They are Integrated Together Sophisticated Controls Technology Integration» Soot Filter Regeneration Strategy Model Fidelity to Different Types of Soot Oxidation Mechanisms Kinetic Data» Urea Injection and Mixing Improvement Small Urea Flow Rate Control Uniform Urea Distribution» Virtual Sensors and Control (Soot Loading, NH3 Slip) How Can a Complicated 1D System Model Be Simplified to a 0D for On-board Virtual Sensor? Effect of Aging on Aftertreatment Performance» How Modeling Can Capture Aging Effects? Correlation Type or Physical Type? More/Better Kinetic Data Is Required» Industry, Catalyst Suppliers, National Laboratories, and Universities Can Work Together To Fill This Pre-Competitive Void 22
Concluding Remarks Modeling Framework Has Been Further Enhanced. Individual Models Have Been Developed and Validated. Models Have Been Applied to System Integration, and Control Strategy Development, Providing Valuable Design and Testing Directions.» Tier 2 Milestone Results Have Been Achieved Significant Challenges are Ahead 23
Acknowledgments DOE-Freedom Car and Vehicle Technologies DDC Engineering Technologies Team Engelhard Corporation Michigan Tech University Adapco, Gamma Technologies, Ricardo DCX Research & Technology 24