diesel engine waste heat recovery utilizing electric

Caterpillar Engine ResearchDiesel & Emissions Technology

Department of Energy ContractDE-SC05-00OR-22810

Marcelo Algrain and Ulrich HopmannCaterpillar Inc.

2003 DEER ConferenceAugust 25-28, 2003

Newport, Rhode Island

Diesel Engine Waste Heat Recovery Utilizing Electric Turbocompound

Technology


Agenda

Program Objectives and ETC System Background

Update on Component Developments

Air Handling System

Turbo-Shaft Generator and Crankshaft Motor

Control System

Next Steps and Summary


Primary Objectives Demonstrate Technical FeasibilityImprove Fuel Economy

Program Goals and MilestonesConceive and Design Optimum ETC SystemDevelop and Bench Test TurbomachineryDevelop Control System and StrategyRig Test ETC HardwareLab Engine Test of Electric Turbocompound System

Diesel Electric Turbocompounding (ETC)


Modular HVACVariable speed compressor more efficient and serviceable3X more reliable compressor no belts,

no valves, no hoses leak-proof refrigerant lines instant electric heat

StarterGenerator

MotorBeltless engine

product differentiation improve systems design flexibility more efficient & reliable accessories

TruckElectrificationDemonstration

Shore Powerand InverterSupplies DC Bus Voltage from 120/240 Vac 50/60 Hz Input Supplies 120 Vac outlets from battery or generator power

Down ConverterSupplies 12 V Battery from DC Bus

AuxiliaryPower Unit

Supplies DC Bus Voltage when engine is not

running - fulfills hotel loads without idling main engine

overnight

Compressed Air ModuleSupplies compressed air for brakes and ride control

Electric WaterPumpHigher reliability variable speed

faster warm-up less white smoke lower cold weather emissions

Electric Oil PumpVariable speed

Higher efficiency

Technical ApproachElectrify accessories

Decouple them from engineMatch power demand to real time need

Enable use of alternative power sources

Turbocompound


Caterpillar Confidential & Proprietary

MotorGenerator

Engine Control

3

Common Voltage Bus

Powertrain

PowerElectronics

Cooler

2

ElectricLoads

ExhaustGases

Compressor

Engine

EnergyStorage

GeneratorMotor

3

Inpu

ts

4

21Overall

System Controller

PowerElectronics

14

Turbine

Available Turbine Power

0

20

40

60

80

100

120

0 100 200 300 400

Engine Power kW

Turb

ine

Pow

er k

W TurbineCompressor Power

Surplus

FEATURES

No Mechanical Coupling betweenTurbo and Crankshaft

Flexibility in Turbo Operation

Provides Turbo-Assist Capabilities

Lower Fuel Consumption

Working Principle


Electric Turbocompound System

BENEFITSLower Fuel Consumption

Predicted 5% improvement

Controlling Boost enables strategies for reducing transient Particulate EmissionsLower CO2 due to lower Fuel ConsumptionPotential for enhanced Engine Braking with Control of Boost

FEATURES

No Mechanical Coupling between Turbo and Crankshaft

Flexibility in Turbo Operation

Provides Turbo-Assist Capabilities


Progress to DateCompleted Design of Components

Air handling systemElectric Machinery and Power ElectronicsControl System

Run Computer Simulations for Engine Performance Analysis and Dynamic Control Evaluation

Identified Opportunity for Reduced Emissions and Improved Drivability

Built Generator, Crankshaft Motor, and Electronics Remaining Hardware is Being ProcuredSystem Lab Test Planned for 2003 and Engine Test in 2004


Agenda



Air Handling System


Control System



Final Design

Turbine

Bearing Housing

Water Cooling

Compressor

Rotor/ Stator


Turbo Shaft Generator Heat Transfer

Rotor: Temperatures at 60kW

Rotor&Stator: Temperatures at 60 kWEnd Plates-Steel

Voltage: Voltage: 340 VPower: 40 kW / 60kW max.Rotor/Stator Length: 70 mm 340 V

Coil Stator/RotorDensity (kg/m^3) 7800 7980Thermal Conductivity (W/mK) 4.6 29Magnetic Permeability 1 6000Electrical Resistivity (ohm-m) 1.7e-8 4e-7

Stator-ROTELLOY3 Coil-Copper

Rotor-ROTELLOY3

Shaft-Steel


Turbo Shaft Rotor Lamination

FE Analysis

4/6 machine, 4 rotor poles

OD and shape designedfor low stress

Material is ROTELLOY3

Max operating stress below limit

Stress @ 66,500 rpm design speed

Stress @ 80,000 rpm over speed


Modified FE Model

Baseline ModelHigh Temperature andStress Gradients

Decoupled ModelTurbine Housing decoupledfrom Bearing Housing

Decreased WaterpassageLower Stresses


FE Analysis Steady State

Thermal Analysis

Stress Analysis


Compressor Scroll and Compressor Wheel with Diffuser

Compressor and Turbine

Turbine Scroll and Turbine Rotor with Nozzle


Turbo Shaft w/ Ball Bearings

Turbo Shaft

Compressor Wheel on Shaft


Rotor Stator

Windings Dyno.Testing

Turbo Shaft – Generator/Motor


340 Vdc Generator

C-15 Engine

Electronics

Crank Shaft - Motor/Generator & Housing


Engine and VehicleEngine ECU and Fuel ControlEngine Combustion & DynamicsDriveline and Vehicle DynamicsETC Components

Turbomachinery mapsGenerator and Motor Models

Simulated Overall Functionality and Operation of ETC System

Modeled for testing ETC Controller Algorithms

Control System Development


ETC Control System

Boost at Optimum Fuel Consumption

Boost and Fuel Consumption vs. Compound Power

88

92

96

100

15 25 35 45 55Compound Power at Turbo Shaft - kW

Fuel

C

onsu

mpt

ion

- %

50100150200250300350

Boo

st P

ress

ure

- kP

a-a

Fuel ConsumptionBoost Pressure

System Simulation in SimulinkController Implemented in dSpaceVirtual Instrumentation Capabilities

Map Boost / Speed / Load

Set Point for Transient Behavior

0 5 10 15 20 25 30 350

0.5

1B oos t Cont ro l (E ngine S peed = 1800 rpm , V ariab le P res s ure S etpoint )

Dem

and

(0-1

)

0 5 10 15 20 25 30 35

150

200

250

300

Intak e P res s ureS etpoint

Inta

ke P

res.

(kP

a)

0 5 10 15 20 25 30 35

500

1000

1500

2000

2500

Cra

nk T

Q (

N.m

)

Tim e (s ec )

Plant(Engine)

Boost Pressure Feedback

Exhaust Manifold Temperature Feedback

Turbocharger Speed Feedback

Setpoint ElectricMachine

PowerElectronics

ETCController


Agenda



Air Handling System


Control System



Next Steps for ETC Development

Caterpillar Confidential & Proprietary

Complete electric machinery test on dynamometerAdd air-handling components to generator housingConduct SS test of E-turbocharger

in gas-stand lab-settingTest ETC control system

and transient responseIncorporate ETC to C-15 engineMeasure engine performance

with ETC in test-cellDeploy ETC-engine on

future test vehicle


SummaryTurbocharger and ETC System have been

Designed and Analyzed

Performance Predictions Indicate 5% Fuel Economy Improvement

Opportunity for Reduced Emissions and Improved Drivability

Electric Machine Hardware Available

Remaining Hardware is Being Procured

System and Engine Test Planned for 2003 and 2004

Cost/Value Analysis Shows High Customer Value

diesel engine waste heat recovery utilizing electric

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