Development of an SI DI Ethanol Optimized Flex Fuel Engine Using Advanced Valvetrain

Wayne Moore, Matt Foster, Kevin Hoyer, Keith ConferDelphi Advanced Powertrain

DEER ConferenceSeptember 29, 2010

29SE2010 2

Introduction

Project Objective– Minimize the fuel economy penalty currently seen when flex

fueled engines are run on high-percentage ethanol blends

Approach– Increased base engine compression ratio– Control of intake valve closing time with 2 step valvetrain

» Compression ratio management » Load control with effective displacement

Presentation Content– Naturally aspirated operation– Benefits of single intake valve deactivation

29SE2010 3

Hardware Features

2 Step Valvetrain

LIVC High-lift cam EIVC Low-lift cam

DICP Dual Independent Cam PhasingLIVC Late Intake Valve ClosingEIVC Early Intake Valve ClosingCR Compression RatioWOT Wide Open Throttle

2.0 L DITurbocharged

Engine with DICP

Extended Range IntakeCam Phaser

80° crank Intake authority 50° crank Exhaust authority

Custom Pistons Increased CR from

9.2:1 to 11.85:1

29SE2010 4

High Lift

Valvetrain Implementation

Intake Phasing enables effective displacement control

2-Step increases dynamic load range

Low Lift

CAD

Exhaust Intake

TDC Gas Exchange

0 720180 360 5400 Phasing Max Phasing

Intake Cam Phasing (° Cam)

Effe

ctiv

eD

ispl

acem

ent(

L)

-40 -30 -20 -10 00.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

0.6

Low LiftHigh Lift

Valvetrain Effective Displacment ControlE85 Fuel, Unthottled

29SE2010 5

Intake Cam Phasing (° Cam)

BM

EP(k

Pa)

-40 -30 -20 -10 0200

400

600

800

1000

1200

1400

Valvetrain Based Load ControlE85 Fuel, Unthrottled

Low LiftHigh Lift

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open Throttle

Valvetrain Implementation

Unthrottled low load rangePhase from low/high lift

with torque continuity

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

CAD0 180 360 540 720

TDC Gas Exchange

Exhaust Intake

Volume (L)

Pres

sure

(bar

)

0.1 0.2 0.3 0.4 0.5 0.610-1

100

101

102

PV DiagramE85 Fuel, Wide Open ThrottlePV Diagram

E85 Fuel, Unthrottled

29SE2010 6

SOI (° aTDCf)

BSF

C(g

/kW

hr)

EHC

(ppm

),EN

OX

(ppm

)

IMEP

CO

V(%

),SF

N41

5an

dC

O(%

)

300 360 420 480 540200

220

240

260

280

300

0

500

1000

1500

2000

2500

3000

3500

0

0.5

1

1.5

2

2.5

3

3.5

BSFC_KW (g/kW.h)ECO (%)EHC (ppm)ENOX (ppm)S415_FSN (-)EA_COV_of_IMEP

1500RPM Fixed Fuel, 8bar BMEPFixed Cams, High Lift

λ=1, UnthrottledMBT Knock Limited Spark

Opportunities for Valvetrain Optimization

0.4 FSN

Low lift operation vs Speed– Limited charge motion– Slow burn rates at unthrottled

conditions

Soot at high loads with gasoline

3

1

12

2

DYNSP (rpm)

BM

EP(k

Pa)

500 1000 1500 2000 2500 3000 3500 40000

200

400

600

800

1000

454035302520

E85 Unthrottled Speed Load MapLow lift

0 - 10 Burn Durations

0 - 10Burn Duration (°)

% IMEPCOV

HC 800 ppm

Charge Motion Indices for Intake Valvetrain

-0.5

0

0.5

1

1.5

2

2.5

3

Swirl Tumble Swirl Tumble

Cha

rge

Mot

ion

Inde

x

Low Lift2 Valves Active

High Lift2 Valves Active

0 00.5

1.6

29SE2010 7

Valve DeactivationLow lift Deactivation

– Improved Charge Motion– Improved burn rates

Use of high lift deactivation reduces gasoline soot and HC

SOI (° aTDCf)

BSF

C(g

/kW

hr)

EHC

(ppm

),EN

OX

(ppm

)

IMEP

CO

V(%

),SF

N41

5an

dC

O(%

)

300 360 420 480 540200

220

240

260

280

300

0

500

1000

1500

2000

2500

3000

3500

0

0.5

1

1.5

2

2.5

3

3.5

BSFC_KW (g/kW.h)ECO (%)EHC (ppm)ENOX (ppm)S415_FSN (-)EA_COV_of_IMEP

1500RPM Fixed Fuel , 8 bar BMEPFixed Cams, High Lift Deac

λ=1, UnthrottledMBT Knock Limited Spark

11

1.51.51.5

1.5

2 2

DYNSP (rpm)

BM

EP(k

Pa)

500 1000 1500 2000 2500 30000

100

200

300

400

500

600

4542.54037.53532.53027.52522.520

E85 Speed Load MapLow Lift, Single valve deactivation

0 - 10 Burn Durations

0 - 10 Burn Duration (°)

<<0.1FSN

Charge Motion Indices for Intake ValvetrainComparison of 2 Valve vs. 1 Intake Valve

-1

0

1

2

3

4

5

6

7

8

Swirl Tumble Swirl Tumble

Cha

rge

Mot

ion

Inde

x

2 Valves1 Valve

Low Lift High Lift

HC 400 ppm

29SE2010 8

Intake Valve Activation Strategies vs. Baseline

Low lift valve deactivation improves performance

Light throttle for EGR control superior to unthrottled operation

High lift deactivation optimal option for high load / low speed

Baseline is gasoline, 9.2:1 CR performance scaled to E85 LHV

%Im

prov

emen

t

5

10

15

20

25

2000 RPM Load Sweep - E85Intake Valve Deactivation vs. Two valves Active

High Lift and Low Lift

BSF

C(g

/kW

hr)

300

400

500

600

LL Unthrottled / 2VLL Deac. OptimizedLL 2V OptimizedHL Unthrottled / 2VHL 2V OptimizedHL Deac. Optimized

BMEP (kPa)

MA

P(k

Pa)

0 500 10000

20

40

60

80

100

29SE2010 9

Engine Performance (Peak NA Torque) Blends Tested 91 RON E0 Blended with ethanol

– E0, E10, E20, E30, E40, E50, E85

High Ethanol Fuels E50-E85 did not require spark retard E0, E10 Require retard at all speeds

Engine Speed (RPM)

CA

50(°

)

0 1000 2000 3000 4000 50005

10

15

20

25

30

E85E50E20E10E0

Max Torque CurvesEthanol Blends

λ = 1, MBT Knock Limited Spark

Engine Speed (RPM)

BM

EP(k

Pa)

0 1000 2000 3000 4000 5000600

700

800

900

1000

1100

1200

1300

E85E50E20E10E0

Max Torque CurvesEthanol Blends

λ = 1, MBT Knock Limited Spark

deg

aTD

C

Effective CR Reduced for E0, E10 at low speed

29SE2010 10

Conclusions

Reduced E85 fuel penalty from low energy density by 1/3 Valve deactivation improves flame speed and dilution

tolerance with EIVC Light throttle for EGR control more efficient than unthrottled

EIVC Valve deactivation reduces soot and HC for Gasoline at high

loads. E85 capable of improved low end torque. E20 Sufficient for 97% of peak torque with minimal retard.

– Minimal 7% Fuel density penalty

29SE2010 11

Acknowledgment

This material is based upon work supported by the Department of Energy under Award Number DE-FC26-07NT43270

» DOE Technology Development Manager: Kevin Stork» NETL Project Managers: John Jason Conley, Michael Ursic

– Delphi Powertrain; Tim Kunz, Cindy Tawaf, Ray Parker, Steve Crossman, Tom Verstraete, Tim Coha, Eunjoo Hopkins, David Yen, Randy Okenka. Carl McQuillen Racing

– Dr. Ming-Chia Lai, Dr. Xingbin Xie, Atsushi Matsumoto, Yi Zheng, Wayne State University, Detroit, MI

– Additional details will be presented at the 2011 SAE World congress in Detroit.– This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency

thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.