GT-SUITE Conference Nov 09 - Frankfurt

Jonathan Talbot-WeissPerformance Engineer

Bowman Power Group Ltd.Southampton, UK.

&

Ian ThompsonSchool of Mechanical and Aerospace Engineering

Queen's University Belfast

25 November, 2009

Contents

• History of Turbocompounding HD Engines to 90s• Why?• Turbogenerating• Power balance• GT-Power• TG speed control• Test results• Conclusion

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25 November, 2009

History of Turbocompounding Heavy-Duty Engines to 90s

• Turbocharger– Alfred Büchi developed the first turbocharger (1909-1915)

• Mechanical Turbocompounding– Curtis Wright R-3550 cyclone (18 cylinder 55L) first ran

1937, >3500 engines built,– Allison V-1710 E27, development began in 1944 and stopped

in 1946,– Napier Nomad (12 cylinder 65L), first ran in 1949, cancelled

in 1955,– Cummins NH & V903, tested in 1981, improvements between

4.2% & 5.3%.– Scania launched their 12L DT engine

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25 November, 2009

Why?

Near term• Emissions legislation• Fuel economy requirements

Mid term• Fuel economy legislation• Power density

Long term• Sustainability• Ecological• Standard of living

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US Diesel Pump Prices (1994-2009, $ cents/US gal)

European Emission Limits for NOx and PM

25 November, 2009

Turbogenerating

How?• High efficiency compressor and turbines

– Compressor efficiency 79% (peak)– Turbine efficiency 87% (peak)– Fixed NGV rings to allow on- engine optimisation without VGT– Wide operating efficiency range

• Turbogenerator speed control• Advances in E-machines & power electronics• Commercialisation of hybrid vehicles

Benefits• BSFC improvement of ~7% on Euro V engines• Maintains engine power with high EGR• Allows engine downsizing without power loss

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25 November, 2009

Power balance – typical HP EGR baseline

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Thermal Efficiency

=349kW/867kW

=40.2%

(Equiv to 210g/kWh)

Thermal Efficiency

=349kW/867kW

=40.2%

(Equiv to 210g/kWh)

25 November, 2009

Power balance – with turbogenerator

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Thermal Efficiency

=349kW/808kW

=43.2%

(Equiv to 194g/kWh)

Thermal Efficiency

=349kW/808kW

=43.2%

(Equiv to 194g/kWh)

25 November, 2009

Turbogenerating - HD engines for automotive applications

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25 November, 2009

Turbogenerating - HD engines for Genets'

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25 November, 2009

GT-Power – at Bowman

• Calibrate engine models• Design & optimise turbomachinery for specific engines

– Simulate future emissions– Investigate the influences of engine timing– Adjust turbomachinery capacities & TG speeds– Monitor PCP, PCT, E-max pressure & temperature– Set up DOEs

• Model different fuels• Model impact using different technologies

– Very high EGR rates (up to 55%), HP, LP or split

• Simulate different engine duties

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25 November, 2009

GT Power model - 12L using Biogas and Palm Oil

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25 November, 2009

GT Power model - Scania 12L Calibration

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Measured:• Manifolds• Cylinder pressure trace• Port CDs

25 November, 2009

GT Power model - Scania 12L Test results

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Measurement Simulation Diff vs. actual result

Engine grid power (kW) 231.7 0.7%

TG power (kW) 28.3 3.7%

Total fuel power (kW) 566.2 0.1%

Turbocharger speed (krpm) 82.8 0.6%

Compressor reduced mass flow (kg.s-1.√K.MPa-1)

60.76 0.2%

Compressor pressure ratio 2.52 1.2%

TC Turbine reduced mass flow (kg.s-1.√K.MPa-1)

61.70 0.8%

TC Turbine expansion ratio 1.79 5.6%

TG Turbine reduced mass flow (kg.s-1.√K.MPa-1)

67.90 0.0%

TG turbine expansion ratio 1.72 5.5%

25 November, 2009

GT Power model - Scania 12L Planned Work

• Optimise the turbochargers• Optimise the TG, its speed & impose a TG speed profile• Optimise the engine timing & CR• Explore further improvements to the engine i.e. CACs• Develop a generic vehicle model for transient analysis• Develop our DAQ to perform further calculations and

performance maps

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25 November, 2009

TG Speed Control - Ideal Conditions

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Streamlines are nicely aligned with the blade inlet

25 November, 2009

TG Speed Control - Marginal Cond’s

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Stagnation streamline has now shifted round onto the pressure surface

25 November, 2009

TG Speed Control - Speed Mismatch

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Flow is so badly mis-aligned that we have separated flow on the suction surface

25 November, 2009

TG Speed Control – Speed Corrected

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Flow pattern is restored with the increase of speed.

25 November, 2009

ResultsJohn Deere

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Base engine BSFC

BSFC with Turbogenerator

BSFC improvement

BS

FC

im

pro

ve

me

nt

John Deere test results from DEER funded project

9litre off road: 10% BSFC saving at full load across 1500-2100rpm band

Source:

John Deere

25 November, 2009

Test Results

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25 November, 2009

Conclusion

It is critical to understand• Relationship between air mass flow, exhaust pressure with pumping

losses• Weighted profile of engine speed / torque requirements• Integration with / calibration of emission control system• On-vehicle packaging constraints

Keys factors to success are• High efficiency turbochargers to reduce impact of TG stage on pumping

loss of the engines• High efficiency TurboGen® and power electronics to make best use of

remaining exhaust energy• Closely matching TC & TG hardware to the engine AND application

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25 November, 2009

Conclusion

• Presentation– History turbocompounding– What turbogenerating– A GT-Power model– How Bowman optimises their models– Test results for other engines (public domain)

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25 November, 2009

Dr. Jonathan Talbot-Weiss

Performance Engineer

Bowman Power Group Ltd.

Southampton, UK.

E: jtalbot-weiss@bowmanpower.co.uk T: +44 (7866) 68887023

Thank You