improving of conventional combustion engine efficiency in...

Dr. Kurt Kirsten CTO, Engine Systems Business Unit

Schaeffler Group

Improving of Conventional Combustion Engine Efficiency

in Passenger Vehicles by Application of Variable Valve Trains

06.10.2011 Brasov, 2011 Dr. Ing. Kurt Kirsten

1 Motivation to use Variable Valve Trains

2 Process of Conventional Combustion Engines

3 Overview of different Variable Valve Trains

4 Degree of improvement of Conventional Combustion Engines

5 Conclusive Remarks

Improving of Conventional Combustion Engine Efficiency Agenda



MMotivvattionn too ussee Vaariaable VValvve TTraaiinnss11111111111111111111111 Motivation to use Variable Valve Trains






2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 90

110

130

150

170

190

210

230

250

270 Actual Data

Nearest Targets Enacted

Proposed Targets

USA

EU


Improving of Conventional Combustion Engine Efficiency Motivation to use Variable Valve Trains

Mean Values for CO2 Emissions G

ram

s C

O2 p

er K

ilom

eter

NE

DC

test

Based on ICCT March 2010

EUEUEU

Australia

South Korea

Japan

China

14%Propulsion PPPPP

18%Tyres

21% Mechanical Energy


Improving of Conventional Combustion Engine Efficiency Efficiency Chain in a Gasoline Engine

gygyMMechMechEnerggEnerg

E N E R G Y

-2% Convection

-11% Raffinery/Transport

nnnnn-5% Charge Cycle

-25% Heat Losses Coolant

-25% Heat Losses Exhaust Gas

-8,5% Friction

-2,5% Auxiliary Drive y DDrD iive-3% Powertrain Losses n LLLoss

-4% Braking Losses

Sphere of Influence of Valve Train

Mechanical Energy after Combustion

chanical Enehanical E32% 87%

Engine 8EEE

89% Tank TTTTT

100% Crude Oil








PProceesss off CConnveenttionnal Coommbusttioonn EEnnggiinneess22222222222222222222222 Process of Conventional Combustion Engines


Improving of Conventional Combustion Engine Efficiency Technologies for future Gasoline Engines

Variable Charge Motion

Variable Valve Actuation

GDI Stratified

Controlled Auto-ignition

Cylinder Deactivation

Super / Turbo-Charging

Improved Engine

Efficiency

Shifting of Operation

Points

Reduced parasitic losses,

improved energy

management

Most of the Gasoline engine technologies under development are heading for improved thermal efficieny

Improved friction and energy management as add-on to any technology

Engine Speed [rpm] BM

EP [b

ar]

1.000 2.000 3.000 4.000 5.000 6.000 0

2

4

6

8

10

12

14

16

18

20

Charged Engine


Improving of Conventional Combustion Engine Efficiency Fuel Economy Improvement by Shifting of Operation Points

120km/h

90km/h

Engine Speed [rpm]

BMEP

[bar

]

1.000 2.000 3.000 4.000 5.000 6.000 0

2

4

6

8

10

12

14

16

18

20

120km/h

90km/h

Naturally Aspired Engine Variable Charge Motion

Variable Valve Actuation

GDI Stratified

Controlled Auto-ignition

Cylinder Deactivation

Super / Turbo-Charging








OOvervvieew oof diffferrennt VVarriabble Valvvee TTTraainnss3333333333333333333333 Overview of different Variable Valve Trains

Loss Distribution

Spec

ific

Fuel

Con

sum

ptio

n

� b L a W e

� b WW

� bPA

Throttled De-Throttled

Friction

Charge Cycle

Process

Mean Consumption Values for CO2 Emissions

Bra

ke M

ean

Effe

ctiv

e Pr

essu

re

max

min

Speed

� b L a W e


Improving of Conventional Combustion Engine Efficiency Motivation and Basics

P

ficFu

e


Improving of Conventional Combustion Engine Efficiency Required Variabilities

Torq

ue

Engine Speed

Max. Torque Maximum Volumetric Efficiency Early Closure (Short Valve Event)

B A

Max. Power

A

Full Lift Late Closure Greater Overlap

Combustion Optimization (Charge Motion)

CoCD

Optimization of Pumping Losses

C

Optimization of Pumping Losses (Combustion Optimization)

E

Cyl

inde

r Pr

essu

re

Volume

IC’

IC

IC’

IC



Miller Miller

Atkinson Atkinson

Port Deactivation Port Deactivation

Valve Phasing Valve Phasing

Cylinder Deactiv. Cylinder Deactiv

Event Length Event Length

De-Throttling Concept

Improved Cycle (Cooling Effect � EIC)







Atkinson Atkinson

Miller Miller

IC CIC

Cyl

inde

r Pre

ssur

e

Volume

IC’

De-Throttling Concept

Excess Gas Mass is recharged during Compression






Miller Miller


Atkinson Atkinson

Hea

t Rel

ease

Crank Angle

Swirl Pool

Conventional Intake Port

Stable and effective Combustion




Atkinson Atkinson

V l Ph i


Miller Miller



EV2

EV1

Cyl

inde

r Pr

essu

re

Volume

IC’

IC C

IC’

ICH

eat R

elea

se

Crank Angle C k A

Swirl Pool

Conventional Intake Port

Combination of De-Throttling and Charge Motion




Atkinson Atkinson

V l Ph i


Miller Miller



EV2

EV1

Drag Curve

Speed

Torq

ue

bemin max be

min beSpeed

Torq

ue

bemin

Shift of Area of Operation

De-throttling and Improvement in High Cycle Efficiency




Atkinson Atkinson

V l Ph i


Miller Miller



EV2

EV1

Avoid Interacting of Exhaust Ports (I4 Engine)

Improve EGR Scavening

Pres

sure

Crank Angle

Exhaust Gas Reverse Flow

Intake Opening

Exhaust Closing

Cylinder 1 Cylinder 3 Cylinder 4

PSR PExhaustGas

Variable Valve Train Variable Valve Train

Lift and Timing


Improving of Conventional Combustion Engine Efficiency Overview of Valve Train Variabilities

Discrete (switchable) Two-Step

Tappet Pivot Element Finger Follower Shifting Cam Roller Lifter

Three-Step Rocker Arm Shifting Cam

g

Continuous Electrical-Magnetic Mechanical

e.g. Valvetronic

Electro-Hydraulic UniAir

Phasing

Continuous Hydraulic Electro-Mechanical


Improving of Conventional Combustion Engine Efficiency Overview of Valve Train Variabilities

Switchable Tappet

Switchable T t

Switchable Pivot Element

Switchable Pivot El t

Switchable Roller Finger Follower

Switchable Roller Fi F ll

Shifting Cam Lobe

Shifting Cam L b

Electro-Hydraulic Actuated

Electro-Mechanical Actuated (Enlarged Temperature Range)

Profile Switching

Valve Deactivation (1 Valve per Cylinder)

Cylinder Deactivation (All Valves per Cylinder)

Internal EGR (Recharge)

Internal EGR (Recapture)

Crossing of Valve Events

2-Step

3-Step

n


Improving of Conventional Combustion Engine Efficiency Overview of fully variable Valve Train Variabilities

Mechanical Mechanical Electro-Magnetic Electro-Magnetic Electro-Hydraulic Electro-Hydraulic

AVL / Bosch EHVT

FEV MV2T

Valeo E-Valve Valeo INA / FIAT

UniAir/ MultiAir

INA / FIAT

Lotus AVT

Lotus

Hilite Univalve

Hilite Honda A-VTEC Honda INA

3CAM INAMeta

VVH Meta Mitsubishi

MIVEC Mitsubishi

Toyota Valvematic

ToyotaINA EcoValve

INA Nissan VVEL

Nissan Presta DeltaValveControl

Presta Sturman HVA

Sturman

Toyota 3D-CAM

Yamaha CVVT

Yamaha Delphi VVA

Delphi Fiat 3D-CAM

FiatMahle VLD

MahleSuzukiSNVT Suzuki

= Systems in Mass Production

BMW Valvetronic II

BMW

Engine Map Fuel Consumption � enhanced models (gas exchange and high pressure process)


Improving of Conventional Combustion Engine Efficiency Complete Vehicle Simulation

GT-Power GT-Drive/ Dymola GT Drive/ DymolaGT-Power

NEDC


Improving of Conventional Combustion Engine Efficiency Evaluation of Potential: Procedure

Basic Motor

Downsizing Concept (turbocharged 4 Cylinder-DI-Engine)

Car Model

Medium-Sized Vehicle

Manual Transmission

bar

min -1 (Speed)

NEDC

Valv

e Li

ft

No Lift No Lift Optimization

Effort

Evaluation of Potential of different Switching

Stages

Cylinder 2 Cylinder 3 Cylinder 4 Cylinder 1

2-Step

2-Step (CDA)

3-Step

3-Step (Cylinder selective)

Val

ve L

ift

Val

ve L

ift

Crank Angle

Val

veLi

ft

Phas

e of

Inta

ke

Exhaust Gas Rate

BMEP g / kW h

ExG

2 0

3 0

4 0

5 0

6 0

7 0

W

0

350

12

14

16 18

20 22

24

400

500

600

700

800

K

9

2 3 4 5 6 7 m 9

Inlet Pressure

n = 2 1 0 0 m i n - , BMEP = 1 , 1 b a r 1


Improving of Conventional Combustion Engine Efficiency Example of Optimization I

Lift of Intake

60

70

WKWW


Improving of Conventional Combustion Engine Efficiency Example of Optimization II

t i

9 . 6 9.69 . 9 9 . 4 6 . 5

6 . 0

4 . 8 3 . 4

1 . 9

h V = 4 , 4 - 4 , 7 m m

h V = 6 , 2 - 7 , 4 m m

h V = 3 , 5 m m

9 . 3 1 0 . 8

Fuel Consumption Improvement relative to Base Version

B

MEP

Speed

t i n % 1 0 9 . 5 9 8 . 5 8 7 . 5 7 6 . 5 6 5 . 5 5 4 . 5 4 3 . 5 3 2 . 5 2 1 . 5 1 0 . 9 0 . 8 0 . 7 0 . 6 0 . 5 0 . 4 0 . 3 0 . 2 0 . 1 0

999999..66666 99999....66666669..99 9999..444 666666..5

66666..0000

444444.888833333333...4444444444

11111....99999

hV= 4,4 - 4,7 mm

hV= 6,2 - 7,4 mm

hV= 3,5 mm

9999999999...3333331100000.88

Fuel Consumption Improvement relative to Base Version t in %

109.598.587.576.565.554.543.532.521.510.90.80.70.60.50.40.30.20.10

0

2

4

6

8

10

12

14

16

bar

20

0 500 1000 1500 2000 2500 min - 1 3500








DDegreeee of immproovvemmeennt oof CConvennttiioonnaal CCoommbbusssttiion EEngineess4444444444444444444444 Degree of improvement of Conventional Combustion Engines

Basis 2-Step 3-Step 2-Step

(CDA)



Improving of Conventional Combustion Engine Efficiency Degree of improvement of Conventional Combustion Engines

2-Step (all Cylinders) 2-Step (all Cylinders)

3-Step (all Cylinders) 3-Step (all Cylinders)

Cylinder Deactivation Cylinder Deactivation

3-Step (Cylinders set) 3-Step (Cylinders set)

100% -5,7% -6% -10,2% -11%


Improving of Conventional Combustion Engine Efficiency Results with customer-specific Drive Profiles

Higher dynamics than NEDC.

The Hyzem cycles consist of an urban cycle, an extra-urban cycle, and a highway cycle.

Basis 2-Step (CDA) 3-Step (Cylinder selective)

2-Step (CDA)



Improving of Conventional Combustion Engine Efficiency Degree of improvement of Conventional Combustion Engines

NEDC NEDC

Hyzem Hyzem

Cylinder Deactivation Cylinder Deactivation

3-Step (Cylinders set) 3-Step (Cylinders set)

Hyzem

100%

Hyzem NEDC

-10,2% -11%

-3,3% -7,4%


Improving of Conventional Combustion Engine Efficiency Potential for Consumption Improvements

Friction Improvements FFFFFFFFFFFFFrrrrriiiiiiiiiiiiicccccttttttttttttiiiiiiiiiiiiiooooonnnnn IIIIIIIIIIIIImmmmmppppprrrrrooooovvvvveeeeemmmmmeeeeennnnnttttttttttttsssss

2-3% Friction Reduction

2-3% Demand Controlled Accessories

Further Improvements FFFFFFFFFFFFFuuuuurrrrrtttttttttttthhhhhhhhhhhhheeeeerrrrr IIIIIIIIIIIIImmmmmppppprrrrrooooovvvvveeeeemmmmmeeeeennnnnttttttttttttsssss

1-2% Thermo-Management

5-8% Downsizing

3-5% Stop-Start Function


<3% Diesel

<7% Gasoline

Combustion System Optimization

4-6% Pumping Losses Gasoline








CConclusivee RRemmaarkss 55555555555555555555555 Conclusive Remarks


Improving of Conventional Combustion Engine Efficiency Conclusions

Conclusive Remarks

Nobody exactly knows what the powertrain world will really look like in 2020 and beyond

But: The potential for further innovations, and the associated opportunities for reducing CO2 emissions are highly promising and far from beeing exhausted

Variable valve train technology is a key element in realizing further improvements

Drive cycle and drive train layout need to be included to come to a final evaluation

The assessment of improvement potential also need to consider the impact and aspects of the monitoring and control technology


Dr. Kurt Kirsten CTO, Engine Systems Business Unit

Schaeffler Group

Improving of Conventional Combustion Engine Efficiency Conclusions

improving of conventional combustion engine efficiency in...

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