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Super Truck Program: Engine Project Review

Recovery Act – Class 8 Truck Freight Efficiency 

Improvement Project

PI: Kevin Sisken (Engine); Derek Rotz (Vehicle)

Presenter: Kevin Sisken

Detroit Diesel Corporation

May 17, 2012

Project ID: ACE058

This presentation does not contain any proprietary, confidential, or otherwise restricted information
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Overview

• Project start: April 2010

• Project end: March 2015

• Percent complete: 40%

• High efficiency SCR unit had higher than 

desired pressure drop. Design being 

iterated.

• Integrate electric power generating systems 

with hybrid power bus and controls

Budget

Timeline Barriers

Partners

• Total project $79,119,736

• Engine Budget $31,633,001

– DOE Share(*) $4,494,000 

– DTNA Share (*) $9,042,000 

(*) Program total through Dec 2011 for engine 

R&D expenses only, vehicle R&D expenses 

reported separately

• Department of Energy

• Oak Ridge National Laboratory

• Massachusetts Institute of Technology

• Atkinson LLC

• Daimler Trucks North America

• Daimler Advanced Engineering
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Objectives and Milestone

Timeline Phase Description Milestones

4/10–3/11 (1) Technology Modeling/Analysis and Initial 

Component Development and Demonstration

Develop analytical roadmap:

•50% vehicle freight efficiency improvement

•50% engine brake thermal efficiency 

4/11–3/12 (2) Experimental Demonstration of Technology 

Building Blocks for Intermediate Goals

Experimentally demonstrate technology building blocks:

• 25% vehicle freight efficiency improvement (system level test)

• 46% engine brake thermal efficiency

4/12–5/13 (3) Technology Identifications and Final 

Component Development and Demonstration

Identify and initially develop technology building blocks:

•50% vehicle freight efficiency improvement (system level test & analysis)

•50% engine brake thermal efficiency

6/13–6/14 (4) Experimental Demonstration of Technology 

Building Blocks for 50% Engine Thermal 

Efficiency and 50% Vehicle Efficiency

Experimentally demonstrate technology building blocks:

•50% vehicle freight efficiency improvement (system level test)

•50% engine brake thermal efficiency 

7/14–3/15 (5) Final System Integration and Demonstration Experimental demonstration:

•50% vehicle freight efficiency improvement (entire vehicle test)

•50% engine brake thermal efficiency (engine test)

•55% engine brake thermal efficiency (engine analysis)

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Relevance

Develop and Demonstrate a 50% total increase in vehicle freight efficiency:

• At least 20% improvement via a heavy-duty diesel engine capable of achieving a 50% brake thermal efficiency

• Identify key pathways towards achieving a 55% brake thermal efficient engine through modeling and analysis
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Super Truck Core Engine Development

Technical Accomplishments and Progress

Demonstrate 50% brake thermal efficiency via:

 Engine downsizing (higher BMEP)

 Higher compression ratio

 Air system optimizations, reduced EGR

 Reduced parasitic

 Waste heat recovery
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Higher Peak Firing Pressures

 Raised peak firing pressure by 10% in test. Will increase by 20% 

over baseline this year.

 Increase compression ratio by 2 points over the baseline

 Re-matching injector tip to new piston bowl

Air System Rematch

 Leveraging higher SCR conversion efficiency 

to reduce EGR rates

 Higher airflow rates requires a turbo rematch

 Prototype turbocharger on order

 Prototype turbocompound unit on order

Technical Accomplishments and Progress
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Increased Engine Out NOx

 Significantly reduced EGR

 Calibration adjusted to maintain good SCR temperatures

 Significant bsfc benefit measured

Aftertreatment

 Thinner wall DPF showed very low dP. DPF will 

benefit from higher NOx/PM ratio (low soot load)

 Increased SCR cell density and alternative catalyst 

material. Testing showed high SCR conversion 

efficiency (95 to 100%), but high SCR dP.

 Iterating SCR design

Technical Accomplishments and Progress

BSFC gains vs. baseline 

obtained to-date ( ↓ EGR)
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Engine Parasitic Reduction via Downsizing

 40% motoring power reduction at 

cruise RPM

 Higher BMEP at road load

Engine Downsizing Via 

Cylinder Deactivation

 Cylinder deactivation was evaluated as a way to 

increase BMEP

 Measurable BSFC benefit at low loads

 Limiting factors (namely exh. temperature and 

airflow) necessitate turbocharger rematch.

 Not being pursued further

Technical Accomplishments and Progress
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SuperTruck Engine Controls – Objective

 Develop a predictive

engine controller

 Include a fuel efficiency 

optimizer

 Integrate predictive vehicle 

information

 Reduce calibration 

Extensive engine mapping is used complexity in neural network model training

Emissions & fuel economy models 

enable on-board BSFC optimization

Predictive Hill 

Detection

Predictive route information enables 

enhanced use of engine optimization.

Calibration Constraints 

 Drivability

 Durability

 Fuel economy

 Life-cycle cost

 NOx / PM / NMHC / CO2

 OBD

 Exhaust temperature

 GPS / Route / Traffic info.

Technical Accomplishments and Progress
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Engine Mapping

 Extended number of 

controlled variable

 Evaluated controller on 

SuperTruck routes (20 and 

40-minute dyno cycles)

 Controller response is 

predictable and repeatable

 Engine controller 

relies on extensive 

engine mapping

 Data is obtained 

under transient 

conditions

Controller Evaluation Over Transient Cycles

Technical Accomplishments and Progress

NOx (ppm)
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 Demonstrated controller’s ability to modulate 

NOx in real-time

 5% lower BSFC over highway ST cycle

 4.8% lower BSFC over urban ST cycle

 Will use route information (GPS, terrain, traffic, 

etc.) to leverage the engine controller’s ability 

to optimize the engine in real-time

Integrate With Super Truck’s Predictive Capabilities

Technical Accomplishments and Progress
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Reduced Engine Parasitics

 Water pump improvements completed, 0.5% BSFC 

improvement

 Development work on lower friction kit (piston, rings, liner) 

continues. Initial bench testing was positive, engine testing did 

not show same results. Development continues.

 Evaluating alternative oils

Technical Accomplishments and Progress

MIT Friction

 Evaluated where potential for friction improvement was 

largest with special attention to oil temperatures

 Looking at component optimizations for oil temperature 

control within system for friction reduction

 Significant modeling completed and effort continues
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Waste Heat Recovery Test Bed

 Test fixture designed, and built

 Allowance for additional instrumentation and easy 

installation in a test cell

 Component location relative to each other same as planned 

for vehicle

Technical Accomplishments and Progress

Waste Heat Recovery Control System

 Test bed control system designed and functional

 Further refinement in process to allow for running on 

vehicle 
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Waste Heat Recovery Modeling

 Modeling of waste heat recovery continues for both 

component sizing and overall system optimization

 Multiple models being utilized; Daimler in-house model 

and Oak Ridge National Laboratory model

Technical Accomplishments and Progress

Working Fluid

 Selection criteria considered:

 Low environmental impact, thermodynamic 

performance, acceptable operating pressures, high 

thermal stability, etc.

 Ethanol selected
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Waste Heat Recovery Packaging

 Current system using exhaust gas recovery only. Packaging 

and design of EGR recovery in process

 Packaging studies in vehicle underway. Significant studies 

into cooling system impact completed (DTNA lead)

Technical Accomplishments and Progress

Waste Heat Recovery Testing

 Test fixture installed in dedicated waste heat recovery test cell

 Successful shakedown of fixture and controls

 Boiler and condenser evaluations in process

 Expander/generator in final assembly
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Generator

 Partnered with Oak Ridge National Laboratory (ORNL) for 

development of generator

 Utilized low cost wound field generator as opposed to 

permanent magnet machine.

 Prototype build in process with delivery expected April 2012. 

ORNL will perform performance testing.

Technical Accomplishments and Progress

Expander  Scroll expander selected as primary option for WHR

 Magnetic coupling to allow hermetic sealing of expander 

and simple interface to generator

 Expander in final assembly. Supplier will perform basic 

testing. Delivery expected April 2012.

Magnetic

coupling

Scroll

expander
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 High NOx/PM  Passive only particulate filter 

regeneration

 Predictive engine controls

 Weight neutral design; added waste heat system, 

downsized the engine

 Engine geared for low rpm operation

 Clutched air compressor

Technical Accomplishments and Progress

Vehicle Only Benefits (not Thermal Efficiency)
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Collaboration and Support

 Department of Energy Head Quarters

 Gurpreet Singh

 Roland Gravel

 National Energy Technology Laboratory

 Carl Maronde

 Oak Ridge National Laboratory

 Waste heat recovery system

 Massachusetts Institute of Technology

 Low friction technologies

 Atkinson LLC

 Advanced engine controls
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Summary and Future Work

 Second year of Super Truck program complete

 Engine has demonstrated 46.2% brake thermal efficiency

 Plans firmly in place for next level of performance improvement:

 Higher compression ratio including new piston bowl and injector tip

 Iterate SCR design for lower pressure drop

 Reduced engine parasitics

 Continue controls development and refinement

 Waste heat regeneration development

 Expander and generator

 Add EGR waste heat recovery

 Integrate onto vehicle