Diesel Engine Waste Heat Recovery Utilizing Electric Turbocompound Technology
Department of Energy ContractDE-SC05-00OR-99OR22734
Ulrich HopmannCaterpillar Inc.
2004 DEER ConferenceAugust 30-Sept 2, 2004San Diego, California
Caterpillar Engine ResearchDiesel & Emissions Technology
Agenda
• Program Objectives and Electric Turbocompound (ETC)
System Background• Update on Component Developments
– Turbo-shaft generator and crankshaft motor – Air handling system– Control system– Component testing
• Cost/Value Study• Next Steps and Summary
Caterpillar Engine ResearchDiesel & Emissions Technology
Diesel Electric Turbocompounding (ETC)
• Primary Objectives:– Demonstrate technical feasibility– Improve fuel economy
• Program Goals and Milestones:– Conceive and design optimum ETC
system– Develop and bench test
turbomachinery– Develop control system and strategy– Rig test ETC hardware– Lab engine test of ETC system
Caterpillar Engine ResearchDiesel & Emissions Technology
Caterpillar Engine ResearchDiesel & Emissions Technology
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
Predicted 5 to 10% reduction in fuel consumption
Working Principle
Caterpillar Engine ResearchDiesel & Emissions Technology
Program Objectives and ETC System Background
Update on Component DevelopmentsTurbo-shaft generator and crankshaft motorAir handling systemControl systemComponent testing
Cost/Value Study
Next Steps and Summary
Agenda
Caterpillar Engine ResearchDiesel & Emissions Technology
Turbine
Bearing Housing
Water Cooling
Compressor
Rotor/ Stator
Final Design
Caterpillar Engine ResearchDiesel & Emissions Technology
Final Design
Caterpillar Engine ResearchDiesel & Emissions Technology
Rotor Stator
Windings Dyno Testing
Turbo Shaft – Generator/Motor
Caterpillar Engine ResearchDiesel & Emissions Technology
Flywheel Housing with Crank Shaft M/G
340 Vdc Crank Shaft M/G Electronics
Crank Shaft - Motor/Generator
Caterpillar Engine ResearchDiesel & Emissions Technology
Compressor Scroll and Compressor Wheel with Diffuser
Turbine Scroll and Turbine Rotor with Nozzle
Design Point
Pressure Ratio (t-s) 3.1
Efficiency (t-s) 82%, max. 85%
Design Point
Pressure Ratio (t-s) 3.7
Efficiency (t-s) 84%, max. 85%
Compressor and Turbine
Caterpillar Engine ResearchDiesel & Emissions Technology
Turbo Shaft w/ Ball BearingsRotor Assembly with Balancing
Fixture
Turbo Shaft & Bearing Housing
Caterpillar Engine ResearchDiesel & Emissions Technology
Turbine Housing
Speed Pick-Up
Compressor VoluteHousing for Motor/Generator
Proximity Probes
Electrical Power Take Off
Assembled ETC Turbocharger
Caterpillar Engine ResearchDiesel & Emissions Technology
Set Point for Transient Behavior
0 5 10 15 20 25 30 350
0.5
1B oos t Control (E ng ine S peed = 1800 rpm , V ariab le P res s ure S etpo int)
Dem
and
(0-1
)
0 5 10 15 20 25 30 35
150
200
250
300
In tak e P res s ureS etpoin t
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 )
Map Boost / Speed / Load
System Simulation in SimulinkController Implemented in dSpaceVirtual Instrumentation Capabilities
Engine
Boost Pressure Feedback
Exhaust Manifold Temperature Feedback
Turbocharger Speed Feedback
ElectricMachine
PowerElectronics
ETCController
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
Con
sum
ptio
n -
%
60
80
100
120
Rel
ativ
e B
oost
- %
Fuel ConsumptionBoost Pressure
ETC Control System
Caterpillar Engine ResearchDiesel & Emissions Technology
Turboshaft and crankshaft motor/generator (M/G) have beentested on separate test rigs
Measured peak efficiency of crankshaft M/G at target level
ETC turbocharger is being tested on gas stand
Rotor dynamics check
Compressor map
Turbine map
Engine test planned for October 2004
Component Testing
Caterpillar Engine ResearchDiesel & Emissions Technology
Program Objectives and ETC System Background
Update on Component Developments
Turbo-shaft generator and crankshaft motor
Air handling system
Control system
Component testing
Cost/Value Study
Next Steps and Summary
Agenda
Caterpillar Engine ResearchDiesel & Emissions Technology
Program is based on MY 2000 engine
Value of ETC Technology
3 to 5% bsfc reduction
No need for waste gateEnhanced braking power through
Higher boost Regenerative braking with crank m/g
Turbo assist capabilitiesControl A/F ratio (gas engines)Improved cold startabilityAltitude capability
Cost/Value Study
Caterpillar Engine ResearchDiesel & Emissions Technology
System – Cost/Value: Example On-Highway Truck
ETC system cost
cost increment turbo
M/G turboshaft
M/G crankshaft
powerelectronics
Customer Benefit
Payback period between 13 (best case) and 38 months
System cost: $ 2000 to $ 3400
Powerelectronics account for half the cost
Caterpillar Engine ResearchDiesel & Emissions Technology
Next Steps for ETC Development
• Complete test of ETC turbocharger in gas-stand lab-setting
• Complete engine testing with ETC system
• Assess ETC on low emission engine– Packaging– Aerodynamics– Cost effective design– Reliability/durability demonstration
Caterpillar Confidential & Proprietary
Caterpillar Engine ResearchDiesel & Emissions Technology
Summary
• Turbocharger and ETC system have beendesigned and analyzed
• Performance predictions indicate 3 to 5% fuel economy improvement for cycle, 10% at key operating point
• Opportunity for reduced emissions and improved drivability
• E-Machine hardware testing completed• Cost/value analysis shows high customer
value