Development of Dual-Fuel Engine for Class 8 Applications

(Dept of Energy Supertruck Program)

Acknowledgements: DOE Contract: DE-EE0003303 Industrial Partners: ARGONNE, WERC, BOSCH, Federal Mogul

Yu Zhang, William de Ojeda, Dennis Jadin

Navistar Inc. Andrew Ickes, Thomas Wallner Argonne National Laboratory

David Wickman Wisconsin Engine Research Consultants

Technical Session: High-Efficiency Engine Technologies Part 2

DOE DEER CONFERENCE 18 October 2012

Dearborn, Michigan

1

Outline

2 2

Background - High Efficiency Combustion Modes - Base Engine and Efficiency Target Development Strategy - Fuel Reactivity Options - Fueling Strategy - Efficiency Roadmap Results - Gasoline + Diesel - Alcohol/Gasoline + Diesel Summary

High Efficiency Combustion Modes

3 3

Diesel Combustion HCCI Fuel Reactivity

Charge Preparation

Fuels

Combustion Modes

Reactivity Stratification

DI Homogeneous PFI + DI

Diesel Flexible, Single

Diffusion Premixed High Reactivity Low Reactivity

Low High

Controllability Poor Good

Challenges Controllability Controllability

Load Limitation Load Limitation High PM & NOx

Fuel Reactivity

Provides flexibility in tailoring combustion process by manipulating PFI/DI ratio Widens load range by introducing reactivity stratification

Dual-Fuel

Base Engine and Efficiency Target

MY 2010 MAXXFORCE 13 o common rail fuel injection system o regulated 2-stage turbocharger

with intercooler o 2-stage HP loop EGR cooling Rated Power 475hp

MAXXFORCE 13 Dual-Fuel multi-point port fuel injection dual-fuel control system variable geometry turbocharger variable valve actuation optimized piston geometry high pressure common rail

Project Target: Demonstrate a technical path towards 55% BTE with fuel reactivity

Fuel Reactivity Efficiency Roadmap

5

Significant improvement on BTE with fuel reactivity At better controlled engine out emissions

Progress to Date

Diesel 45%

at ~1gNOx

Alcohol/Gasoline + Diesel 45.1%

NOx ~ 0.1gNOx

Gasoline + Diesel 43.6%

NOx ~ 0.1gNOx

43.6% 45.1%

Current Target Reactivity + CR

BTE > 47% at NOx < 0.15gNOx

47%

VVA CR

TUCO Friction

ORC

Technologies from the Diesel

platform

Fuel Reactivity Options

6 6

Gasoline

Port Fuel Injection

Alcohol/Gasoline Blends High Octane Alt.

Increased octane number AKI:93

lower reactivity suppresses charge autoignition oxygenates provide additional benefit in soot

Direct Injection

Diesel Synthetic Diesel FACE #1

longer ignition delay • improved mixing • less soot

CN:30 CN:45 CN >70

robust ignition source • enhance combustion

stability at late SOIs • mitigate PRR

-15

-10

-5

0

5

10

15

20

25

-70 -60 -50 -40 -30 -20 -10 0 10

CA50

[°AT

DC]

SOIm [°ATDC]

PFI%:80PFI%:85PFI%:90

Fueling Strategy Development PFI% Diesel Injection Strategy Load Range:

• low-to-medium: CM1-SS, CM1-MS, CM2-SS

• medium-to-high: CM1-SS

Fuel Reactivity Fueling Strategy

1

Combustion phasing is robustly coupled to diesel SOI (CM1):

1

2

2 Combustion phasing is largely controlled by charge reactivity (CM2):

IVCIVO TDC

IVCIVO TDC

IVCIVO TDC

CM1 Single-Shot

CM1 Multi-Shot

CM2 Single-Shot

low reactivity high reactivity

7

0.17

0.19

0.07

0.06

0.18

0.17

0.16

0.07

0.18

0.18

0.19

0.06

0

3

6

9

12

15

18

21

24

1100 1300 1500 1700 1900

BMEP

[bar

]

Speed [RPM]

NOx [g/hp-hr]CM2-SS

8

Fuel Reactivity Gasoline + Diesel – Overview

full load

o CM1 led to wider low temperature combustion range than CM2 o CM2 yielded lower NOx and soot than CM1

0.08

0.05

0.040.03

0.05

0.03

0.02

0.110.04

0.02

0

3

6

9

12

15

18

21

24

1100 1300 1500 1700 1900BM

EP [b

ar]

Speed [RPM]

NOx [g/hp-hr]

CM1-SS

0.01

0.130.18

0.46

0.04

0.12

0.13

0.18

0.09

0.10

0.13

0.17

0

3

6

9

12

15

18

21

24

1100 1300 1500 1700 1900

BMEP

[bar

]

Speed [RPM]

CM1Smoke [FSN]

0.01

0.03

0.170.18

0.03

0.07

0.08

0.100.11

0.06

0

3

6

9

12

15

18

21

24

1100 1300 1500 1700 1900

BMEP

[bar

]

Speed [RPM]

CM2 Smoke [FSN]

Best BTE :43.6%

revert to diffusive combustion

9

Fuel Reactivity Gasoline + Diesel – CM1 vs.CM2

1200 rpm; 10 bar BMEP

o Comparable fuel efficiency o CM2 demands more EGR and higher gasoline% o Combustion characteristics:

• CM1 combustion proceeds through two-stages • CM2 combustion goes through a single-stage heat release

0

100

200

300

400

500

600

700

800

900

1000

-60

-40

-20

0

20

40

60

80

100

120

140

-40 -30 -20 -10 0 10 20 30 40

HRR [J/deg]

Pres

sure

[bar

]

CA [deg]

CM1 CM2

CM1 CM2

BTE (%) 42 42

Gasoline (%) 84 93

NOx (g/hp-hr) 0.05 0.03

Smoke (FSN) 0.32 0.18

SOI (aTDC) -12 -58

EGR (%) increase

diesel + entrained gasoline

primarily gasoline

0100200300400500600700800900100011001200

-60

-40

-20

0

20

40

60

80

100

120

140

-40 -20 0 20 40

HRR [J/deg]

Pres

sure

[bar

]

CA [deg]

6 bar 8 bar 10 bar 11.6 bar

10

Fuel Reactivity Gasoline + Diesel – Combustion Characteristics

1200 rpm

o CM1 heat release peaks merge with load increase o Towards load-limit, higher gasoline% led to more premixed combustion and

higher PRR

76% gasoline

81% gasoline

84% gasoline

86% gasoline

11

Fuel Reactivity Alcohol/Gasoline + Diesel – Performance

Alcohol/gasoline extended LTC load range to 19 bar BMEP

Fuel-bound oxygen led to soot reduction improved fuel efficiency

• best BTE: 45.1%

35%

37%

39%

41%

43%

45%

47%

5 10 15 20 25

BTE

[%]

BMEP (bar)

A/G+DG+DSTK High Eff. Diesel

>7 bar load extension

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

5 10 15 20 25

Smok

e N

umbe

r [F

SN]

BMEP [bar]

A/G+DG+DSTK High Eff. Diesel

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

5 10 15 20 25

BS N

Ox

[g/h

p-hr

]

BMEP (bar)

A/G+DG+DSTK High Eff. Diesel

12

Fuel Reactivity Alcohol/Gasoline + Diesel vs. Gasoline + Diesel

o Alcohol/gasoline showed less rapid second-stage heat release o Alcohol/gasoline allowed for more advanced SOI and earlier combustion phasing

without sacrificing soot and PRR

G+D A/G+D

BTE (%) 43.6 43

PFI (%) 84 78

EGR (%)

SOI (aTDC) -7 -13

NOx (g/hp-hr) 0.06 0.08

Smoke (FSN) 0.46 0.11

1200 rpm; 11.6 bar BMEP

0

200

400

600

800

1000

1200

-150

-100

-50

0

50

100

150

-40 -20 0 20 40

HRR [J/deg]

Pres

sure

[bar

]

CA [deg]

G+D A/G+D

reduce

13

Fuel Reactivity Alcohol/Gasoline + Diesel – Combustion Characteristics

Alcohol/gasoline led to wider heat release spread and better contained PRR

0

200

400

600

800

1000

1200

1400

-150

-100

-50

0

50

100

150

200

-40 -20 0 20 40

HRR [J/deg]

Pres

sure

[bar

]

CA [deg]

11 bar 14 bar 19 bar

75% A/G

84% A/G

90% A/G

14

Fuel Reactivity Summary

Project Target: Demonstrate a technical path towards 55% BTE with fuel reactivity

Milestones: Phase I with gasoline + diesel demonstrated LTC operation up to 11.6 bar BMEP with

best BTE of 43.6% Phase II with alcohol/gasoline + diesel achieved LTC operation up to 19 bar BMEP with

best BTE of 45.1%

Further Improvements Further exploration of fuel reactivity Combustion system optimization (CR, piston geometry) Air system upgrade (VVA+turbo)

Acknowledgements Engine Project Partners

TM

Combustion Simulation

Fuels Enabling Technologies

15

WERC BOSCH ARGONNE NATIONAL

LABORATORY

Yu Zhang Navistar, Inc.

2601 Navistar Drive Lisle, IL 60532

Yu.Zhang@Navistar.com

FEDERAL MOGUL