Electric Turbo Compounding… A Technology Who’s Time Has Come

• Carl T. Vuk

• John Deere Technical Center

OUTLINE • System Architecture • Review of Hardware Elements

• System Analysis • Test Results • Application Recommendations • Conclusions • Future Work • Questions

24 Aug, 2006

Electric Turbo Compounding: • A System That Converts Waste Exhaust Energy

to Shaft Work, using a Turbine, and Couples it Back to the Engine, Electrically

Why Turbo Compounding ? • Today’s Engines Reject 40% of the Fuel’s Energy in the

Exhaust Gas Stream. The Exhaust is an Excellent Source of High Grade Heat, And it’s Free!

• Turbo Compounding Technology is Available and Proven With Mature System Costs in the Order of $50/kW.

• The Technology Provides Power Growth, Improved Fuel Economy, and Reduced Emissions.

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24 Aug, 2006

System Architecture

Turbo Generator

• Converts Exhaust Energy into Shaft Work

• Converts Shaft Work into Electrical Power• Simple Architecture • Very High Efficiency • Known Technology • Cost Effective Design

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Motor Generator

• Generates When Turbo Gen Can Not (Generating Mode) • Couples Turbo Gen Power Back to Engine (Motoring Mode)• Flywheel Mounted for Compact Packaging • Simple Low Cost Machine Using Known Technology • High Efficiency BPM Technology

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Power Electronics

• Controls Turbo Gen Speed and Delivers DC Power• Manages Motor Gen to Regulate BUS Voltage • Very High Efficiency Over Operating Envelope • Cost Effective Components • Liquid Cooled

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Advanced TurboCharger

• High Pressure Turbine • Significantly Upgraded Efficiency • Fixed Geometry Turbine Nozzle Vanes

• Vaned Diffuser (Compressor)

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24 Aug, 2006

Dyno Test Setup Advanced Turbocharger

Power turbine

Generator

Two Stage Architecture

• Independent Control of Turbo Machinery Elements • Modest Pressure Ratios • Interstage After Treatment • Allows for Simple Turbo Machinery • Improved Transient Response

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Electric Coupling • Power Turbine Speed Control Optimization • Efficient Power Recirculation w/o Fluid Coupling

• Packaging Flexibility • Motor Generator Supports Vehicle Electrification

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Variable Geometry Turbines • VG TurboCharger Not Needed to Drive EGR • VG Power Turbine - Option

• Provides Direct Control of Turbo Compounding Output • Increases Part Load & Part Speed Output • Potential Control of Engine Air Flow & Transient Response

• Fixed Geometry Power Turbine – Option • Better Efficiency at Full Load • Reduced System Complexity • Lower Cost

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Variable Vane Mechanism (Power Turbine)

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Variable Vane Mechanism (Power Turbine)

Motor Generator Optimization • Efficiency Must be High (95%) in Operating Envelope • Packaging is Critical For Common Design and Minimal

Vehicle Disruption • Every Application is Different. Assuming Will Not Produce

Optimal Results

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Engine Test Data (Output Characteristics) TG Power vs. Load and Speed: TG3 w/-20% & -39% NGV, BW VTG, PCU1 - 7Sep05

0 200 400 600 800 1000 1200 1400

Engine Load - Nm

w/ Tier 3 Emissions Injection Timing and EGR Schedules

0

5

10

15

20

25

30

35

40

45

50

55

60

TG P

ower

- kW

e

2300 RPM - TG3 w/-39% NGV - BW VTG 2300 RPM - TG3 w/-20% NGV - BW VTG 2300 RPM - TG3 w/Nom NGV - BW VTG 2100 RPM - TG3 w/-39% NGV - BW VTG 2100 RPM - TG3 w/-20% NGV - BW VTG 2100 RPM - TG3 w/Nom NGV - BW VTG

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Engine Performance Data (Fuel Economy)

Fuel Economy: Combined Engine Shaft + Electric Power Outputs

300 500 700 900 1100 1300

Engine Load - Nm

190

195

200

205

210

215

220

225

230

235

240

245

250

255

260

Com

bine

d SF

C -

g/kW

h

Non-Turbocompound Baseline Engine

Turbocompound Engine

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Application Targets – Turbo Compounding

• High-Duty Cycle Steady State Operation MaximizesBenefit

• High Annual Usage Improves Payback • Vehicle Electrification Helps Justify Added Cost

• Motor/Gen Needed Even w/o TurboCompounding • More Efficient to Use Electrical Power in Vehicle

• Power Growth • Valuable in Some Applications • Allows Smaller Higher Duty Cycle Engines in

Applications Not Needing Power Growth

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Ideal Applications

Combines

Large Tractors Row Crop Tractors

Trucks

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Tractor Mounted Turbo Generator

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Hardware Integrated in Tractor

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Deere 9L Engine in International Truck

Conclusions: • 20% Power Growth Has Been Demonstrated With Little

Adverse Impact On The Engine. Higher Output is Possible. • Fuel Economy Improvements of 10% Have Been

Demonstrated at Tier 3 Conditions • Turbo Compounding is Compatible With Emissions and

Appears to Provide Benefit • An Electrically Coupled Two Stage Architecture offers

Control, Efficiency, Emissions, and Packaging Benefits. It Also Supports Electrification.

• System Costs Suggest Commercialization Potential

24 Aug, 2006

Future Work • Evaluate Benefits of the Variable Geometry Power Turbine

• Characterize Performance Benefits in Vehicles • Deere Tractor • On-Highway Truck

• Expand Scope to Include Larger Engines • Develop Next Generation Hardware

• Optimize for Tier 4

24 Aug, 2006

Acknowledgements • I would like to thank John Deere, US Department of Energy,

International Truck, and Eaton for support of this program, and for allowing us to share a high level overview of this work.

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24 Aug, 2006

Questions ?