the potential of electric exhaust gas turbocharging for … · gt-suite users international...

GT-Suite Users International ConferenceFrankfurt a.M., October 10th 2005

THE POTENTIAL OF ELECTRIC EXHAUST GAS

TURBOCHARGING FOR HD DIESEL ENGINES

F. Millo, F. Mallamo, (POLITECNICO DI TORINO, ITALY)E. Pautasso

G. Dellora, G. Ganio Mego (IVECO S.P.A., ITALY)

J. Bumby, S. Crossland (UNIVERSITY OF DURHAM, UK)

O. Ryder (HOLSET TURBOCHARGERS, UK)

L. Jaeger, L. Montali (IVECOMOTORENFORSHUNG LTD, CH)

Presentation overview

• Introduction

• Contest

• Building the engine and vehicle model

• Analysis of possible fuel consumption

reductions and performance enhancements

• Conclusions

INTRODUCTION

THE AIM OF THE RESEARCH PROJECT WAS TO ANALYSE THE POTENTIAL OF AN ELECTRIC ASSISTED TURBOCHARGER FOR A HEAVY-DUTY DIESEL ENGINE, REPLACING THE CURRENT VARIABLE GEOMETRY TURBINE WITH A FIXED

GEOMETRY TURBINE AND CONNECTING TO THE TURBO SHAFT AN ELECTRIC MACHINE WHICH CAN OPERATE BOTH AS AN ELECTRIC MOTOR AND AS AN ELECTRIC GENERATOR

• Introduction

• Contest


• Analysis of possible fuel consumption reductions and performance enhancements

• Conclusions

INTRODUCTIONTHE ELECTRIC MACHINE OPERATES AS A MOTORWHEN THE INTERNAL COMBUSTION ENGINE SPEEDS UP FROM IDLE AND AFTER GEAR SHIFTS IN ORDER TO HELP THE TURBOCHARGER TO ACCELERATE AND SO TO REDUCE THE TURBO-LAG, REDUCING PARTICULATE EMISSIONS DURING TRANSIENTS, ENHANCING THE ENGINE PERFORMANCE AND SO ALLOWING ENGINE DOWNSIZING.

• Introduction

• Contest



• Conclusions

0.5

1

1.5

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2.5

3

3.5

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BO

OS

T P

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. [ba

r]

VGT

ELECTRIC. ASS.TURBO

THE ELECTRIC MACHINE OPERATES AS A GENERATOR WHEN IT IS POSSIBLE TO EXTRACT FROM THE EXHAUST GASES MORE ENERGY THAN THAT WHICH IS NECESSARY TO REACH THE TARGET BOOST PRESSURE.

THE ELECTRIC ENERGY WHICH IS PRODUCED IS PROVIDED TO THE VEHICLE ELECTRIC SYSTEM REDUCING THE ELECTRIC LOAD ON THE ALTERNATORS AND SO THE AUXIALIARY POWER REQUIREMENT, WITH AN OBVIOUS FUEL CONSUMPTION REDUCTION.

MOREOVER, THE TORQUE ABSORBED BY THE ELECTRIC MACHINE ALLOWS THE CONTROL OF THE TURBO SPEED, WITHOUT THE NEED FOR A WASTEGATE OR A VGT.

INTRODUCTION• Introduction

• Contest



• Conclusions

HOWEVER, THE POTENTIAL OF THIS KIND OF SYSTEM IS STRONGLY DEPENDENT ON THE DRIVING CYCLE (I.E. REGENERATION PERIODS WHEN THE ELECTRIC MACHINE OPERATES AS A GENERATOR SHOULD BE LONG ENOUGH TO PRODUCE AND STORE THE ENERGY THAT WILL BE REQUIRED TO SPEED-UP THE TURBOCHARGER DURING THE ACCELERATION TRANSIENTS OF THE INTERNAL COMBUSTION ENGINE).

THEREFORE, A DETAILED SIMULATION MODEL IS REQUIRED IN ORDER TO ASSESS THE SYSTEM POTENTIAL.

INTRODUCTION• Introduction

• Contest



• Conclusions

CONTEST:

THE ELEGT PROJECTELECTRIC EXHAUST GAS TURBOCHARGER

RESEARCH PROJECT FUNDED BY THE RESEARCH DIRECTORATE OF THE EUROPEAN UNION COMMISSION

• PROJECT CO-ORDINATOR : IVECO S.p.A.PARTNERS :

• 1) IVECO S.p.A. (IVECO) I

• 2) Iveco Motorenforschung LTD (IMF ) CH

• 3) HOLSET Engineering LTD (Holset) UK

• 4) Thien-E-motors LTD (Thien) A

• 5) ATE GMBH (ATE) D

• 6) University of Durham (Durham) UK

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL

MAIN ENGINE FEATURES

CYCLE DIESEL 4 STROKE

N° CYLINDERS 6 IN LINE

DISPLACEMENT [dm3] 7.8

BORE [mm] 115

STROKE [mm] 125

COMPRESSION RATIO 17:1

MAXIMUM TORQUE [Nm] 1280 AT 1080 RPM

MAXIMUM POWER [kW] 259 AT 2400 RPM

AIR INTAKE SYSTEM

SINGLE STAGE TURBOCHARGER (WITH VGT AND AFTERCOOLER )

IVECO CURSOR 8

• MAX. BMEP 20.6 BAR

• SPEC. OUTPUT 33 KW / dm3

CURRENTLY IN PRODUCTION HD DIESEL ENGINE (IVECO CURSOR 8) WITH VGT WAS USED AS A REFERENCE

• Introduction

• Contest



• Conclusions

INTERCOOLER

INTAKE MANIFOLD

EXHAUSTMANIFOLD

TURBOCHARGER

ENGINE CRANKSHAFT

CYLINDERS8 ENGINE SPEEDS AND 5 LOAD LEVELS FOR A TOTAL OF 40 OPERATING POINTS USED FOR MODEL VALIDATION

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5

10

15

20

25

700 1200 1700 2200n [rpm]

B.M

.E.P

. [ba

r]

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL

DETAILED GT-POWER MODEL

BUILDING THE ENGINE AND VEHICLE MODEL:ENGINE MODEL VALIDATION

FULL LOAD OPERATING CONDITIONS

AIR MASS FLOW TURBO SPEED

ENGINE EFFICIENCY BMEP

• Introduction

• Contest



• Conclusions

200

400

600

800

1000

1200

1400

750 1000 1250 1500 1750 2000 2250 2500n [rpm]

AIR

FLO

W [

kg/h

]

EXP.SIM.

20

25

30

35

40

45

50

750 1000 1250 1500 1750 2000 2250 2500n [rpm]

EN

G. E

FF. [

% ]

EXP.SIM.

5

10

15

20

25

750 1000 1250 1500 1750 2000 2250 2500n [rpm]

BM

EP

[bar

]

EXPSIM

60

70

80

90

100

110

120

130

750 1000 1250 1500 1750 2000 2250 2500

Engine speed [rpm]

Turb

o S

peed

[rpm

]

EXP.SIM.

BUILDING THE ENGINE AND VEHICLE MODEL:

VEHICLE MODEL

SIMULATED VEHICLE :

URBAN BUS (12 tons UNLOADED, 16.5 tons FULL LOADED)

AUTOMATIC GEARSHIFT WITH TORQUE CONVERTER

COUPLED ENGINE + VEHICLE MODEL INITIALLY VALIDATED

ON SIMPLE DRIVING CYCLES

COUPLED ENGINE-VEHICLE MODEL VALIDATION

DRIVING CYCLE EXP. FUEL CONS. [L/100KM]

SIM. FUEL CONS. [L/100KM]

SORT1 49.2 ÷ 46.8 47.7

SORT2 42.2 ÷ 38.2 42. 9

• Introduction

• Contest



• Conclusions

0102030405060

0 151time [s]

Spe

ed [k

m/h

]

0102030405060

0 179time [s]

Spe

ed [k

m/h

]

BUILDING THE ENGINE AND VEHICLE MODEL:ELEGT SYSTEM ARCHITECTURE

ALTERNATOR

ENGINE VEHICLE

TURBINE COMPRESSOR

ELECTRIC MACHINE

SUPERCAP.

DC/DC CONV.

ELECTRIC LOAD (24V)

DC BUS (350V)

ELECTRIC MACHINE CONTROL SYSTEM

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL:ELEGT SYSTEM ARCHITECTURE

SIMULINK MODEL OF ELECTRIC SUBSYSTEMS (UNIV. OF DURHAM) COUPLED WITH ENGINE AND VEHICLE GT-POWER MODEL (POLITECNICO DI TORINO)

ELECTRIC MACHINE CONTROL SYSTEM

ENERGY MANAGEMENT CONTROL SYSTEM

- ELECTRIC MACHINE - SUPERCAPACITORS - DC/DC CONVERTER

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL:

ELECTRIC MACHINE MAIN FEATURES

350 VoltsVOLTAGE

130.000 rpmMAXIMUM DESIGN SPEED

MOTOR/GENERATOR

MAXIMUM OVERSPEED

USAGE

TORQUE & POWER

USAGE

TORQUE & POWER

143.000 rpm

CONTINUOUS

CONSTANT GENERATING POWER ( 7.6 kW )GENERATOR

INTERMITTENT (3 s USE IN A 20 s CYCLE)

CONST. TORQUE ( 1 Nm ) UP TO 60.000 rpm, CONST. POWER ( 6.3 kW ) UP TO 120.000 rpmMOTOR

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL:ELEGT CONTROL SYSTEM

AT FIRST THE ELECTRICAL POWER GENERATED BY THE ELEGT SYSTEM IS USED TO CHARGE THE SUPERCAPACITORS. WHEN THEIR SOC (STATE OF CHARGE) IS HIGHER THAN 0.65 THEY START TO PROVIDE TO THE VEHICLE ELECTRIC SYSTEM THE POWER USUALLY GENERATED BY ONE ALTERNATOR.

IF THE SYSTEM GENERATES CONTINUOUSLY THE SOC LEVEL CONTINUES TO INCREASE. WHEN IT RISES ABOVE THE 0.85 LEVEL, ALSO THE SECOND ALTERNATOR ELECTRIC POWER CAN BE SAVED.

ON THE CONTRARY IF THE SYSTEM GENERATES DISCONTINUOUSLY OR DOESN’T GENERATE AT ALL THE SOC LEVEL DECREASES AND WHEN IT GOES BELOW A LOWER LIMIT THE LOAD REQUIRED TO THE SUPERCAPACITORS IS SET TO ZERO, AS, CONSEQUENTLY, THE POWER ADDED TO THE ENGINE.

THE INSTANTANEOUS ELECTRIC POWER PROVIDED BY THE ELEGT SYSTEM IS CALCULATED DURING THE WHOLE DRIVING CYCLE.

• Introduction

• Contest



• Conclusions

BUILDING THE ENGINE AND VEHICLE MODEL:ELEGT CONTROL SYSTEM• Introduction

• Contest



• Conclusions

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BOOST TARGET

MOTOR (1) OR GEN (2)

EXAMPLE OF CONTROL STRATEGY DURING THE FIRST 20 s OF THE HWFET DRIVING CYCLE

BUILDING THE ENGINE AND VEHICLE MODEL:ELEGT CONTROL SYSTEM• Introduction

• Contest



• Conclusions EXAMPLE OF CONTROL STRATEGY DURING A PERIOD OF 80 s IN THE HWFET DRIVING CYCLE

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300 320 340 360 380Time [s]

Pow

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0.00.20.40.60.81.01.21.41.61.82.02.2

SO

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MO

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POWER SAVING FOR I.C.E.

Motor or Generator

SOC

FROM THIS POINT SOC > 0.65, 1st ALTERNATOR CAN BE SWITCHED OFF

FROM THIS POINT SOC > 0.85, ALSO 2nd ALTERNATOR CAN BE SWITCHED OFF

• Introduction

• Contest



• Conclusions

ANALYSIS OF POSSIBLE FUEL CONSUMPTION REDUCTIONS AND PERFORMANCE ENHANCEMENTS

CONSIDERED DRIVING CYCLES

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[km

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TRL08Bus in congested traffic

HWFETHighway Fuel Economy

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TRL09Bus in non-congested traffic

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CBDCentral Business District

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TRL03Bus Lane

ANALYSIS OF POSSIBLE FUEL CONSUMPTION REDUCTIONS AND PERFORMANCE ENHANCEMENTS• Introduction

• Contest



• Conclusions

SINCE THE DETAILED ENGINE MODEL IS APPROX. 250 TIMES SLOWER THAN REAL TIME, A MEAN VALUE MODEL WAS BUILT IN ORDER TO REDUCE THE COMPUTATIONAL TIME, BY COMBINING MULTIPLE CYLINDERS INTO A SINGLE MAP-BASED ONE, AS WELL AS SEVERAL INTAKE AND EXHAUST COMPONENTS INTO TWO MANIFOLD COMPONENTS.

ANALYSIS OF POSSIBLE FUEL CONSUMPTION REDUCTIONS AND PERFORMANCE ENHANCEMENTS• Introduction

• Contest



• Conclusions

IN ORDER TO PROPERLY TRAIN THE NEURAL NETWORKS WHICH ARE USED IN THE MEAN VALUE MODEL, A QUITE LARGE NUMBER (ABOUT 1000) OF OPERATING POINTS WERE SIMULATED WITH THE DETAILED MODEL, FOLLOWING A DOE LATIN HYPERCUBE SCHEME. THE INPUT VARIABLES FOR THE NEURAL NETWORKS WERE THE FOLLOWING: −− ENGINE SPEED (FROM 800 TO 2400 RPM), −− FUEL INJECTION RATE (FROM 15 TO 150 MG/CYCLE), −− INTAKE MANIFOLD PRESSURE (FROM 0,9 TO 2,8 BAR), −− EXHAUST MANIFOLD PRESSURE (FROM 1,1 TO 2,45 BAR).

AFTERWARDS, THE MEAN VALUE MODEL RELAIBILITY WAS TESTED BOTH UNDER STEADY STATE AND TRANSIENT OPERATING CONDITIONS

2

4

6

8

10

12

750 1000 1250 1500 1750 2000 2250 2500Engine speed [rpm]

BM

EP

[bar

]

SIM. DETAILED

SIM. MEAN VALUE

0.9

1.2

1.5

1.8

2.1

2.4

2.7

3

0 20 40 60 80t [sec]

Boo

st p

ress

ure

[bar

]

SIM. DETAILED

SIM. MEAN VALUE


3.2

4.2

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CBD TRL03 TRL08 TRL09 HWFET

Fuel

con

sum

ptio

n re

duct

ion

[%]

SIMULATION RESULTS

FULL LOADED VEHICLE (16.5 tons)

• Introduction

• Contest



• Conclusions


SIMULATION RESULTS


3.2

4.2

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5.4

5.96.2

1.6

4.0

6.4

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4

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6

7

CBD TRL03 TRL08 TRL09 HWFET

Fuel

con

sum

ptio

n re

duct

ion

[%]

Original turbine mapsModified turbine maps

MODIFIED TURBINE MAPS

• Introduction

• Contest



• Conclusions


SIMULATION RESULTS


5.96.2

4.0

6.4

4.55

2.8

5.3

0

1

2

3

4

5

6

7

CBD TRL03 TRL09 HWFET

Fuel

con

sum

ptio

n re

duct

ion

[%]

Alternator efficiency=55%Alternator efficiency=75%

ALTERNATOR AVER. EFFIC. 75% INSTEAD OF 55%

• Introduction

• Contest



• Conclusions


TURBO LAG REDUCTION: TURBO SPEED

• Introduction

• Contest



• Conclusions10000

30000

50000

70000

90000

110000

130000

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5time [s]

TUR

BO

SP

EE

D [

rpm

]

VGT

ELECTRIC. ASS.TURBO


TURBO LAG REDUCTION: BOOST PRESSURE

• Introduction

• Contest



• Conclusions 0.5

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1.5

2

2.5

3

3.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5time [s]

BO

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. [ba

r]

VGT

ELECTRIC. ASS.TURBO

CONCLUSIONS

THANKS TO THE USE OF MEAN VALUE MODEL, THE ELEGT SYSTEM POTENTIAL COULD BE ASSESSED ALSO ON COMPLEX, REAL WORLD DRIVING CYCLES, LEADING TO THE FOLLOWING MAIN FINDINGS:

- THE ELEGT SYSTEM ALLOWS A FUEL CONSUMPTION REDUCTION FROM 1.5% TO 5.5% DEPENDING ON THE DRIVING CYCLE;

- THESE VALUES COULD BE INCREASED BY CONSIDERING AN “ON PURPOSE” DESIGNED TURBINE;

- FUEL SAVINGS ARE STILL APPRECIABLE EVEN IF BETTER EFFICIENCY ALTERNATORS ARE CONSIDERED;

- SUBSTANTIAL IMPROVEMENTS DURING THE ACCELERATION TRANSIENTS CAN BE ACHIEVED

• Introduction

• Contest



• Conclusions

ACKNOWLEDGMENTS

THIS WORK HAS BEEN CARRIED OUT WITH THE FINANCIAL SUPPORT OF THE EUROPEAN COMMUNITY IN THE FRAMEWORK OF THE EUROPEAN COMMISSION “GROWTH”PROGRAMME.

CONTRACT N°: 63083

PROJECT N°: G3RD-CT-2002-00788

ACRONYM : ELEGT

TITLE : ELectric Exhaust Gas Turbocharger

• Introduction

• Contest



• Conclusions

GT-Suite Users International ConferenceFrankfurt a.M., October 10th 2005

THE POTENTIAL OF ELECTRIC EXHAUST GAS

TURBOCHARGING FOR HD DIESEL ENGINES

F. Millo, F. Mallamo, (POLITECNICO DI TORINO, ITALY)E. Pautasso

G. Dellora, G. Ganio Mego (IVECO S.P.A., ITALY)

J. Bumby, S. Crossland (UNIVERSITY OF DURHAM, UK)

O. Ryder (HOLSET TURBOCHARGERS, UK)

L. Jaeger, L. Montali (IVECOMOTORENFORSHUNG LTD, CH)

the potential of electric exhaust gas turbocharging for … · gt-suite users international...

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