Southwest Research Institute® San Antonio, Texas

Developments in High

Efficiency Engine Technologies

DEER 2012

Drivers for High Efficiency

Demand for low

CO2 engines

Oil Price Volatility

Energy Security

Climate Change

Air Quality

Government Regulations

US 2025:107

EU 2020: 95

Japan 2020: 105China 2020: 117

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2000 2005 2010 2015 2020 2025

Gra

ms

CO

2pe

r kilo

met

er, n

orm

aliz

ed to

NED

C

US-LDV

California-LDV

Canada-LDV

EU

Japan

China

S. Korea

Australia

Solid dots and lines: historical performanceSolid dots and dashed lines: enacted targets Solid dots and dotted lines: proposed targetsHollow dots and dotted lines: unannounced proposal

[1] China's target reflects gasoline fleet scenario. If including other fuel types, the target will be lower.[2] US and Canada light-duty vehicles include light-commercial vehicles.

CAFE – not just for light duty anymore

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Engine AMY 2007

Engine BMY 2007

Engine CMY 2008

Engine DMY 2011

2014Standard

2017Standard

Fuel

cons

umpt

ion

[g/k

Wh]

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

0 5 10 15 20

Idea

l Ott

o Cy

cle

Effic

ienc

y

Geometric Compression Ratio

γ = 1.5

γ = 1.3

γ = 1.4

Fundamental Efficiency Drivers

•Sets the ceiling for the engine •Gamma is a function of

–Charge composition

–Temperature • In the real-world, high compression ratios have some unwanted side effects

111 −−= γη

cotto r

Sources of Real-World Losses in IC Engines

BMEP

Engine Speed

Heat Transfer Friction

Combustion Efficiency Cycle Efficiency / Charge Properties

BMEP

Engine Speed

Sources of Real-World Losses in IC Engines

Pumping Work (SI + CI w/ LTC or HPL EGR)

BMEP

Engine Speed

Sources of Real-World Losses in IC Engines

Combustion Phasing SI – Knock Control CI – Emissions, PCP Limits or Noise Control

BMEP

Engine Speed

Sources of Real-World Losses in IC Engines

Enrichment (LD SI only)

Two Paths to High Efficiency

Brake Power

Coolant Heat

Losses

Exhaust Heat

Losses

Cycle Losses

Friction Losses

Hot Combustion

Combustion Losses Pumping Work

Brake Power

Coolant Heat

Losses Exhaust

Heat Losses

Cycle Losses

Friction Losses

Cold Combustion

Pumping Work Combustion

Losses

Hot vs Cold Combustion Cold Hot

Heat Transfer Losses ++ - - Combustion Phasing + (++ for SI) 0 (- - for SI) Charge Properties + 0 Emissions (engine-out) + - Emissions (cycle or tailpipe) 0 + Boosting - - ++ Engine Control - + Hardware Requirements (e.g. PCP) - 0 Waste Heat Recovery Potential - (LPL EGR)

+ (HPL EGR) +

Enrichment (SI only) ++ - -

Path to High Efficiency May Depend on Application

General Engine Improvements

Cold Combustion

Hot Combustion

General Engine Improvements

Friction

Parasitic Losses

Architecture Improved Boosting Systems

Electronics & Controls

Research Goals and Topics for Pre-Mixed Combustion

Goal: High

Compression Ratio

Downsizing and Downspeeding

Primary Problem:

Knock

High Dilution HEDGE®

RCCI PPC

GDCI HCCI

High Octane Fuel

Alternative Architecture

Split-Cycle VCR

Ethanol-Boost

Research Goals and Topics for Diffusion Combustion

Goal: High Efficiency

and Low Emissions on

Highly Loaded Duty Cycle

Primary Problem: Emissions

NOx PM

Low Dilution Diesel Engines

Low Dilution Dual-Fuel Applications

Waste Heat Recovery

High Efficiency Aftertreatment

What’s Next?

•Many potential configurations to address these challenges •Industry assessment required

Cost

Performance

Durability Emissions

Robustness η

Southwest Research Institute® San Antonio, Texas

Introduction to SwRI’s Dedicated EGR

Concept DEER 2012

What is Dedicated EGR (D-EGR)?

D-EGR combines highly effective emissions

control technologies and high efficiency potential

of gasoline reformate technologies

Fuel reformed to H2 and CO

ɸ = 1.00 ɸ > 1.00

In-cylinder Reformation • Rich combustion yields

high levels of CO and H2

• In-cylinder reformation may be more efficient than external reformation

– Work still extracted from combustion

– All effort occurs inside the engine block Safer More easily packaged

• Previous work (SAE paper 2007-01-0475) indicated that H2 levels required for combustion optimization are not as high as previously thought

SAE Paper 2009-01-0694

Impacting the Working Fluid with D-EGR

Cool combustion + dilution + reformate =

higher γ

Higher γ = Improved ηotto

1.1 < Dφ < 1.5

1.00 1.05 1.10 1.15 1.20 1.250

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4

6

8

10

CoV

IMEP

[%]

Cylinder #1 φ

Enabling High EGR Tolerance

2000 rpm / 2 bar bmep Test Platform

2006 MY 2.4 L Chrysler World Engine 14:1 CR

Faster combustion = Improved Stability at 25% EGR

Increased Knock Resistance

Reformate Impact on Effective RON

+ Faster Burn Rates =

Improved Knock Tolerance

1.00 1.05 1.10 1.15 1.20150

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Knoc

k Li

mite

d Pe

ak T

orqu

e [N

-m]

Dedicated Cylinder φ

2000 RPM WOT

Reduced Emissions •Combustion efficiency returns to nearly non-dilute levels •Reformate improves HC and CO emissions •NOx emissions increase slightly

– Still ~ ¼ of non-dilute case 2000 rpm / 2 bar bmep

Improved Fuel Consumption • BSFC improves considerably

across speed / load range

2000 rpm / 2 bar bmep 1.00 1.05 1.10 1.15 1.20

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Dedicated Cylinder φ

BSFC [g/kWh]

NA Peak Torque [N-m]

14:1 CR NA WOT @ 2000 rpm

Most Recent Results • 2.0 L L4 TC MPI Application

– 12.5:1 CR – Advanced ignition system – Average D-EGR cylinder φ =

1.3

• Mean BSFC improvement : ~ 12-15%

• Best BTE to date : > 41% • Best BSFC at 2000 rpm / 2

bar bmep : 315 g/kWh • Lower BSFC than a Tier II

Bin 2 diesel with GDI performance and ultra-low emissions / no PM

What is Next for D-EGR? •SwRI will be applying the D-EGR concept to new platforms in HEDGE III program

– 2.0 L TC GDI engine 25% D-EGR

– L6 MD CNG application 33% D-EGR

• Internal funding has been received for demonstration of D-EGR concept on a 2012 MY Buick Regal

– GOAL : 20% improvement in MPG over NA baseline

Thank You

Southwest Research Institute®