2.2mahle downsizing 14-may-2010 gasgoo

7/29/2019 2.2MAHLE Downsizing 14-May-2010 Gasgoo

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MAHLE

The MAHLE Downsizing Engine

High Performance and Low Fuel Consumption

Written by: Volker Korte, Grant Lumsden, Neil Fraser,

Jonathan Hall;

Presented by: Paul WARD


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2MAHLE Powertrain Ltd. MAHLE

Contents

Introduction

Targets

Engine Design

Engine Development

Results and Outlook


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Introduction

Maximising fuel economy and thereby minimising CO2 emissions are among the most importantobjectives for the future development of engines and vehicles.

MAHLE have recently designed and built an engine to demonstrate the application of aggressivedownsizing to gasoline engines in order to improve operating efficiency.

A robust combustion system that allows a high compression ratio to maintain part loadefficiency

Good low speed torque and transient performance

Real world fuel consumption benefits through a reduction in full load fuel enrichment

Base engine robustness and durability


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Targets

The targets were to produce an engine capable of replacing a typical 2.4l V6 PFi engine used ina C or D class European vehicle platform (circa 1600 kg). The engine would be compliant withEU5 / ULEV2 emissions from conception.


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Engine Design

The main engine design parameters


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Engine Design

The main engine design parameters


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Engine Design

Cylinder Head and Combustion Chamber

Tumble inlet ports

Centrally mounted direct injector for spray-guided operation

Cooling around the injector tip

Compact chamber with low surface area


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Engine Design

Air Path and Charging System

High degree of integration The air filter, mass air flow meter and charge cooler

Aluminium charge cooler

Light-weight plastic inlet manifold are, boost levels > 2.8 bar

Cooled exhaust gas recirculation (EGR)

The two-stage system is shown schematically

EGR valve

EGR cooler

Charge

aircooler

Compressor

bypass

HP stage

TurbineBypass Valve

LP stageTurbine

Wastegate

C

C T

T


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> 2.8 bar

ERG

EGR valve

EGR cooler

Charge

aircooler

Compressor

bypass

HP stage

TurbineBypass Valve

LP stageTurbine

Wastegate

C

C T

T


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Engine Design

Cylinder Block and Crank Case

Aluminium bedplate

MAHLE Nikasil parent bore

Through bolting system for cylinder head and block

Piston cooling with feed via separate non filtered oil channel direct from oil pump controlgallery


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MAHLE Nikasil


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Engine Design

Crank Train, Valve Train and Balancer System

Balancer system comprises two crank-driven plastic gears carrying the balance weights

Forged aluminium pistons

A ring pack with two compression rings and a 3-piece oil-scraper ring

DLC coated piston pins

Forged steel conrods

A steel crankshaft


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DLC


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Engine Development

High Load Combustion System

Optimisation of compression ratio and combustion chamber

Optimisation of ignition timing and cam phasing,

Combustion system development

Turbocharger configuration

Piezo injectors in a spray-guided concept

Fuel injection timing,

Fuel pressure (at part load between 100 and 200 bar)

Fuel injection strategy (single or double injection per cycle)


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Engine Development

High Load Combustion System

Example of Camshaft Position Optimization for WOT Performance at3000 rpm (Results at BLD Spark Timing, l = 1.0)


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3000 rpm


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Engine Development

Two-Stage Boosting System


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Engine Development


Initial investigations with single turbochargers have been carried out to define suitableturbine/compressor configurations.

TC01 max. flow 0.06 m3/s




TC01 and TC04 were chosen for testing in

two-stage configuration.

Th MAHLE D i i E i


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TC01 TC04

Th MAHLE D i i E i


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Engine Development


The compressor maps for the TC01 and TC04 plotted together

TC01/TC04 Compressor Maps with Characteristics for approx. 20 30 bar BMEP at 1,500rpm & 2,500 rpm

The MAHLE Do nsi ing Engine


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TC01 TC04

TC01/TC04 . 20 30 bar BMEP 1,500 rpm 2,500 rpm



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Engine Development


Provides a useful improvement in apparent volumetric efficiency

The reduced pre-turbine pressures drive the improved combustion phasing at a givenBMEP



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Engine Development

Transient Response

Transient behaviour is key for the acceptance of downsizing concepts by the customer.

Results of a load step from 2 bar BMEP to WOT at 1,250 rpm



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2 bar BMEP to WOT at 1,250 rpm



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Engine Development

Air Fuel Ratio Engine Map

The objective to operate the engine at l = 1 at all speeds and loads

Objective achieved, except around peak power, without the use of EGR

The maximum exhaust gas temperature has been limited to 1,020 C.



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l = 1

EGR

1,020 C



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Engine Development

Engine Mechanics and Friction

Higher valve-train losses (exhaust spring loads in particular) are the main cause of thesmall disadvantage at low speed.

The good result at medium and high engine speed is due to the very low power-cell frictionof the MAHLE downsizing engine

The effects of 3 vs. 4 cylinders,

Latest technology crank shaft bearings

Short stroke design

Very good bore roundness



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g g


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Results and Outlook

Torque and Power Output at WOT Targets Achieved

Torque at n = 1,000 rpm Md = 153 Nm 153 Nm(BMEP = 16 bar) 16 bar

Max. Torque (n = 3,000 rpm) Md = 286 Nm 287 Nm(BMEP = 30 bar) 30 bar

Max. Power (n = 6,000 rpm) Pe = 144 Kw 144 kW(Pe/VH = 120 kW/l)

Brake Specific Fuel Consumption Targets Achieved

Optimum be < 235 g/kWh 234 g/kWh

n= 2000 rpm, 4 bar BMEP be < 300 g/kWh 285 g/kWh

Torque[Nm]

0

50

100

150

200

250

300

Engine Speed [rpm]

0 1000 2000 3000 4000 5000 6000 7000

Po

wer[kW]

0

30

60

90

120

150

180

TargetsTorque (2-stage turbo)Power (2-stage turbo)

BM

EP[bar]

0

5

10

15

20

25

30

35

Engine Speed [rpm]

1000 2000 3000 4000 5000 6000

325300

300

300

275

275

250

250

234

285

375



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g g


n = 1,000 rpm Md = 153 Nm 153 Nm(BMEP = 16 bar) 16 bar

(n = 3,000 rpm) Md = 286 Nm 287 Nm(BMEP = 30 bar) 30 bar

(n = 6,000 rpm) Pe = 144 Kw 144 kW(Pe/VH = 120 kW/l)

be < 235 g/kWh 234 g/kWh

n= 2000 rpm, 4 bar BMEP be < 300 g/kWh 285 g/kWh

Torque[Nm]

0

50

100

150

200

250

300

Engine Speed [rpm]

0 1000 2000 3000 4000 5000 6000 7000

Po

wer[kW]

0

30

60

90

120

150

180

TargetsTorque (2-stage turbo)Power (2-stage turbo)

BM

EP[bar]

0

5

10

15

20

25

30

35

Engine Speed [rpm]

1000 2000 3000 4000 5000 6000

325300

300

300

275

275

250

250

234

285

375



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Next steps

Simulation of the vehicle fuel economy in the NEDC (kerb weight m 1,600 kg).

This results in an improvement of fuel consumption and CO2 emission of up to 30%



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NEDC m 1,600 kg

30%



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Summary

Targets achieved

Peak power

Peak torque

Low Speed torque

BSFC

Next Step

Vehicle test

Thank-You

Contacts for further information:

Paul WARD

[email protected]

+86 159 2160 1669

Shouping CHEN

[email protected]

+86 138 1722 8830



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Contacts for further information:

Paul WARD

[email protected]

+86 159 2160 1669

Shouping CHEN

[email protected]

+86 138 1722 8830

2.2mahle downsizing 14-may-2010 gasgoo

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