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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 information2 

## 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 Engineering3 

# 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 analysis4 

# 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 recovery5 

# 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 Progress6 

# 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)7 

# 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 Progress8 

# SuperTruck Engine Controls

– Objective

 

### Develop a predictive engine controller

 

### Include a fuel efficiency optimizer

 

### Integrate predictive vehicle information

 

### Reduce calibration complexity Extensive engine mapping is used 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 / CO 2

 OBD

 Exhaust temperature

 GPS / Route / Traffic info. 

### Technical Accomplishments and Progress9 

# 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 ProgressNOx (ppm)10  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 Progress11 

# 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 continues12 

# 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 vehicle13 

# 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 selected14 

# 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 assembly15 

# 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 expander16 

###  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)17 

# 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 controls18 

# 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