The Path to a 50% Thermal Efficient Engine · PDF fileexhaust energy more than thermal...

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The Path to a 50% Thermal Efficient Engine
W. L. Easley, A. Kapic, and D. M. Milam
DOE Contract DE-FC05-00OR22806Team Leader: Gurpreet Singh Prog. Mgr.: Roland GravelTech. Mgr.: Carl Maronde
August 23, 2005DEER Conference

2U.S. DOE
Outline
Objectives
First Law Analysis of Fuel Energy Distribution
Review of Analysis for 45% Brake Thermal Efficiency at 2007 Emissions Levels
50% Brake Thermal Efficiency at 2010 Emissions Levels
Summary and Conclusions

3U.S. DOE
Does improvement in fuel economy offset the cost and maintain durability?
Diesel fueled engine capable of 2010 emissions levels (0.20 g/hp-hr NOx, 0.01 g/hp-hr PM) 50% thermal efficiency >500,000 miles with only minor maintenance Package must fit within class 8 truck
DOE HTCD Program Objectives
High Efficiency Building Blocks
Test Hardware Calibrate Models System Simulation
Real World BenefitSimulation
Results of Past Research
Program Phasing Phase 1: Analytical validation of 45% thermal efficiency at 2007 OHT emissions levels Phase 2: System simulation of 50% thermal efficiency at 2010 OHT emissions levels
with focused component testing

4U.S. DOE
Control Volumes for First Law Analysis
Fuel Energy
Cylinder Heat Rej.
Indicated Power
Exhaust Energy
Reciprocator
CGI Heat Rejection
Engine System
FuelEnergy
Engine Heat Rejection
ExhaustEnergy
ATAAC Heat Rejection
Brake Power
Exhaust Energy
Fuel Energy
Eng. Heat Rej.
Aero Drag
Rolling Res.Drivetrain
Fan
Accessories
Excess Power
On-Highway Truck
ATAAC Heat Rej.
CGI Heat Rej.

5U.S. DOE
0
200
400
600
800
Fuel
Ene
rgy
(kW
)First Law Analysis
45% Thermal Efficient Engine (class VIII truck, 1200 RPM, peak torque, fully loaded, 70 MPH)
On-Highway Truck
Excess Power (65.2 kW; 9.3 %)
Exhaust Power(160 kW; 22.9 %)
Engine Heat Rej.(73.7 kW; 10.5 %)
ATAAC Heat Rej.(103.7 kW; 14.8 %)
Aerodynamic Drag(171.7 kW; 24.6 %)
Rolling Res. (45.9 kW; 6.6 %)
CGIC HR (34.8 kW; 5.0 %)
Reciprocator
Exhaust Power(302.3 kW; 43.2 %)
Heat Loss (58.9 kW; 8.4 %)
Indicated Power(327.0 kW; 46.8 %)
Pumping Power(11.0 kW; 1.6 %)
Engine System
Brake Power(315 kW; 45 %)
CGIC HR (34.8 kW; 5.0 %)
Friction Power(12.0 kW; 1.7 %)

6U.S. DOE
0
200
400
600
800
Fuel
Ene
rgy
(kW
)First Law Analysis
45% Thermal Efficient Engine (class VIII truck, 1200 RPM, peak torque, fully loaded, 70 MPH)
On-Highway Truck
Excess Power (65.2 kW; 9.3 %)
Exhaust Power(160 kW; 22.9 %)
Aerodynamic Drag(171.7 kW; 24.6 %)
Rolling Res. (45.9 kW; 6.6 %)
CGIC HR (34.8 kW; 5.0 %)
Reciprocator
Heat Loss (58.9 kW; 8.4 %)
Indicated Power(327.0 kW; 46.8 %)
Pumping Power(11.0 kW; 1.6 %)
Engine System
Brake Power(315 kW; 45 %)
CGIC HR (34.8 kW; 5.0 %)
Friction Power(12.0 kW; 1.7 %)
Accessories (6.2 kW; 0.9%)
Fan (11.0 kW; 1.6%)
Drivetrain (15.0 kW; 2.1%)

7U.S. DOE
Phase 1: 2007 45% Thermal Efficiency
Improved Port Design
High Efficiency Air SystemReduced PRL Friction
High Efficiency Compact Cooling
System
Combustion System
Optimization
2007 Capable System at 45%
Thermal Efficiency

8U.S. DOE
Reduced Heat RejectionTurbo-Compound
NOxReduction
Combustion System Optimization
Improved Air System
Thermal Efficiency

9U.S. DOE
NOxReduction
Improved Air System
Thermal Efficiency

10U.S. DOE
NOx Reduction
Industry is investigating several technologies for achieving 2010 system-out NOx levels HCCI High diluent
concentration Urea SCR NOx Adsorber
For engine systems employing aftertreatment, engine-out emissions level is determined by conversion efficiency
0.00.51.01.52.02.53.03.54.04.55.0
80 85 90 95 100NOx Aftertreatment Conversion Efficiency (%)
Engi
ne-O
ut N
Ox
(g/h
p-hr
) 1998 Emissions Levels
2004 Emissions Levels
2007 Emissions
Levels
Assuming 0.2 g/hp-hr System-Out NOx
Conversion efficiencies above 90% possible

11U.S. DOE
-5-4-3-2-1012345
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
NOx (g/hp-hr)
Ope
ratin
g C
ost I
ncre
ase
(%)
Conversion of NOx requires additional operating cost in the form of urea, fuel for richening the exhaust stream, etc.
At high conversion efficiencies system optimization more than compensates for operating cost penalty
NOx Reduction
Engine-Out Trade-Off
Curve89% Conversion
83% Conversion
2007 Engine Baseline

12U.S. DOE
BaselineNOx
Reduction
0
200
400
600
800
Fuel
Ene
rgy
(kW
)
ATAACHeat Rej.
EngineHeat Rej.
ExhaustPower
CGIC HR
Friction Power
699.2 kW45.0%
697.0 kW45.2%
BrakePower
Fuel Energy Distribution
Production Challenges long term degradation replenishment of reductant low temperature operation packaging cost
Thermal Efficiency Increase to: 45.2 %
NOx (g/hp-hr)
PM
(g/
hp-
hr)
0.2 1.2System-Out Emissions

13U.S. DOE
Improved Air System
NOxReduction
Thermal Efficiency

14U.S. DOE
Improved Air System
Series turbochargers must be used in order to provide the optimum boost levels
High efficiency compressor, turbine, and bearing designs continue to improve air system component efficiencies
Intercooling can further improve the efficiency of the system
43
44
45
46
47
48
49
65 70 75 80 85 90 95 100 105components (%)
Ther
mal
Effi
cien
cy (%
)
ATAAC w/ 35 C outlet temp.
ATAAC plus ATAIC w/ 35 Coutlet temp.
Syst
em T
her
mal
Eff
icie
ncy
(%
) Demonstrated on LE55 Engine
In Production (used for 45%)

15U.S. DOE
0
200
400
600
800
Fuel
Ene
rgy
(kW
)
ATAACHeat Rej.
EngineHeat Rej.
ExhaustPower
670.6 kW47.0%
CGIC HR
Friction Power
699.2 kW45.0% 697.0 kW45.2%
BrakePower
ATAIC Heat Rej.
BaselineNOx
ReductionImproved Air System
Thermal Efficiency Increase to: 47.0 %
43
44
45
46
47
48
49
65 70 75 80 85 90 95 100 105components (%)
Ther
mal
Effi
cien
cy (%
)
ATAAC w/ 35 C outlet temp.
ATAAC plus ATAIC w/ 35 Coutlet temp.
Production Challenges: packaging cost map width
Sys
tem
Th
erm
al E
ffic
ien
cy (
%)

16U.S. DOE
Improved Air System
NOxReduction
Thermal Efficiency

17U.S. DOE
46.0
46.5
47.0
47.5
48.0
165 170 175 180Total Heat Rejection (kW)
Syst
em T
herm
al E
ffici
ency
(%)
24.0
24.5
25.0
25.5
26.0
Exhaust Energy (%)
Thermal EfficiencyExhaust Energy
Reduced Heat Rejection
Reducing heat rejection: low thermal conductivity
components, coatings, or designs selective cooling higher coolant temperatures
Reduced heat rejection increases exhaust energy more than thermal efficiency
Low Heat Rejection Components from ICC Program
3.5 mm TBC on Piston 2.5 mm TBC on Head 18% Increase in Oil and
Coolant Temperatures

18U.S. DOE
Production Challenges: durability cost
BaselineNOx
AdsorberImproved Air System
Reduced Heat
Rejection
0
200
400
600
800
Fuel
Ene
rgy
(kW
)
ATAACHeat Rej.
EngineHeat Rej.
ExhaustPower
666.5 kW47.3%
670.6 kW47.0%
CGIC HR
Friction Power
699.2 kW45.0%
697.0 kW45.2%
BrakePower
ATAIC Heat Rej.
Thermal Efficiency Increase to: 47.3%

19U.S. DOE
Improved Air System
NOxReduction
2007 Capable Sy

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