Tying Compliance with CARB’s Truck and Bus Regulation to ...
Technology Solutions to Meet Future Heavy-Duty Vehicle ......2019/09/26 · •MECA supports...
Transcript of Technology Solutions to Meet Future Heavy-Duty Vehicle ......2019/09/26 · •MECA supports...
Technology Solutions to Meet Future Heavy-Duty Vehicle Standards
Dr. Rasto BreznyExecutive Director
Manufacturers of Emission Controls Associationwww.meca.org
CARB WorkshopSeptember 26, 2019
Diamond Bar, CA
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MECA Represents Suppliers of Technology Solutions for all Mobility Challenges
Air Handling
Exhaust System Integration
OBD Sensors
Powertrain Electrification
Evaporative Controls
Filters & Substrates
Cooled EGR
Turbo compoundingCylinder Deactivation
Engine Efficiency
What NOx Emissions are Achievable• MECA believes that by 2024 a 0.05 g/bhp-hr limit on the FTP is feasible
without major changes to aftertreatment designs on trucks today.• MECA’s June 2019 white paper highlights technology solutions that
deliver both low CO2 and low NOx in 2024 timeframe.• MECA supports the goal of achieving real world NOx reductions.
–Addition of a low load certification cycle and new in-use compliance requirements will ensure low NOx emissions all the time.
–The same technologies that reduce cold-start emissions deliver reductions during low load and low speed operation.
• By 2027, meeting 0.02 g/bhp-hr NOx over the FTP and low NOx emissions on the LLC are achievable with advanced aftertreatment,engine thermal management technologies and improved calibration.
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US2010 RepackagedUS2013
Evolution of Heavy-Duty Exhaust Control Technology
A natural optimization has resulted in 2019 systems being 60% smaller, 40% lighter, and cheaper than 10 years ago.
US2019
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Better Substrates and Catalysts Improve Conversion at Low Temperatures
• Porous substrates for higher catalyst loading• Low temperature active SCR catalysts for low
temperature operation • And catalyst loading combine for low
temperature activity.
More Active SCR Catalysts at higher Catalyst Loadings Improves Low Temperature Performance
Controlling Porosity reduces Back Pressure of DPF
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Future Exhaust Systems will be Similar to Today Traditional 2019 System
2027 Twin SCR System
Urea Dosing
Cat. DPF SCR DOC SCR/
ASC
Cat. DPF SCR
SCR/ ASC DOC SCR/
ASC
Urea Dosing
• Technologies already deployed on passenger cars will help trucks achieve low NOx emissions on cold-start and in low speed operation.
• Low temperature active catalysts and engine technology like advanced turbos and cylinder deactivation will move from passenger cars to commercial vehicles by 2027.
• Front SCR and dual or heated urea dosing deliver ammonia at the lowest temperatures
• Sophisticated reaction models based on engine out exhaust and temperature information combined with aged catalyst activity to help suppliers design aftertreatment solutions.
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Emission Controls and Engine Thermal Management Can Achieve 2024 and 2027 CARB FTP Targets
• Tailpipe emissions were modeled with engine calibration from SwRI and fully aged commercial catalyst activity.
• An aged 2019 exhaust control system with better engine calibration can meet a 0.05 g/bhp-hr FTP limit
• Advanced catalysts with a front SCR and dual dosing can achieve a 0.02 g/bhp-hrFTP limit
0.05 g/bhp-hr
0.02 g/bhp-hr
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Engine and Powertrain Technologies will Deliver Simultaneous NOx and CO2 Reductions
• Deactivating 2-6 cylinders makes the remaining cylinders work harder and more efficiently• Shutting off all cylinders during idle or coasting keeps aftertreatment hot • High efficiency and driven turbos for catalyst heat-up and waste heat recovery• 48V mild hybrid systems to capture and use braking energy
Turbo compounding
Driven Turbos
48V Hybrid Machines
Cylinder Deactivation
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CDA Delivers Heat and Retains Heat in Low Load Operation
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CDA
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(1=O
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with CDA without CDA CDA On-Off
SwRI Proposed Low Load Cycle (LLC-7)
Source: SAE WCX 2019
Non-optimized CDA results (LLC) No CDA With CDA Improved
CO2 [g/hp-hr] 614 597 2.7%
NOx [g/hp-hr] 1.8 1.0 45%
AT conversion efficiency [%] 58% 76% 31%
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Heated Dosing Allows NOx Reduction at Lower Temperatures • Heated dosing can deliver ammonia in exhaust temperatures as low as 130°C
versus typical 200°C• Can initiate dosing and NOx conversion 5 - 10 minutes sooner during heat-up
from cold start.
Injector for Electric Catalyst
Heated Urea Injector
Source: 2018 Vienna Motor Symposium
Modeling of fully aged Catalysts Suggests that both Exhaust System Architectures can Meet CARB’s LLC Targets
Model Run on Low Load Cycle
SCR System Configuration
SCR Pre-storage with NH3
Urea Dosing
Temp (°C)
Tailpipe NOx (g/bhp-hr)
Baseline Traditional 20% 170 0.38
Scenario 1Traditional with
CDA20% 150 0.25
Scenario 2Twin SCR with
CDA20% 150 0.227
• Using calibrated engine out information from SwRI and NOx conversion tests on full useful life aged catalysts, is an important tool for system design.
• Cylinder deactivation with traditional exhaust systems equipped with heated dosing meets CARB’s LLC NOx emission goals.
• A twin SCR configuration offers additional compliance margin on both the LLC and FTP test cycles.
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Conclusions
• MECA supports CARB’s conclusion that a 0.05 g/bhp-hrNOx limit in 2024 and 0.02 g/bhp-hr in 2027 are achievable.
• The natural migration of engine and exhaust system technologies from passenger cars to commercial vehicles provides proven solutions to meeting 2027 GHG and future low NOx standards.
• Testing at SwRI and catalyst modeling is demonstrating that engine and aftertreatment technologies deliver a 90% NOx reduction below todays standards without dramatically changing the aftertreatment technology that fleets are familiar with.