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Caterpillar Engine Technologies
An Engine System Approach to Exhaust Waste Heat Recovery
Principal Investigator: Richard W. KruiswykCaterpillar Inc.
Note: This presentation does not contain any proprietary or confidential information.
DOE Contract: DE-FC26-05NT42423DOE Technology Manager: John FairbanksNETL Project Manager: Carl Maronde
DEER ConferenceDetroit, MI
August 6, 2008
Caterpillar Confidential: XXXXXEngine Technologies
Caterpillar Non-Confidential
AGENDA
Overview - Engine Thermal Efficiency and Waste Heat Recovery
EWHR Program Objectives, Timeline, Scope
Technical Developments
Summary and Conclusions
Caterpillar Confidential: XXXXXEngine Technologies
Caterpillar Non-Confidential
Diesel Engine Thermal Efficiency
CGI Heat Rejection
FuelEnergy
Engine Heat Rejection
ExhaustEnergy
ATAAC Heat Rejection
Brake Power
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGICooler CGI
BrakePower
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPF
CGICooler CGI
BrakePower
Fuel
• Series Turbocharged• LPL CGI (clean gas induction)
2007 C15 On-Highway Truck
0
20
40
60
80
100
Fuel
Ene
rgy
(kW
)
Fuel Energy, %
~ 10%
~ 22%
Brake Power
CoolantHeat Rej
CGI Cooler HR
ATAAC HR
ExhaustEnergy
~ 42%
~ 21%
~ 5%
Caterpillar Confidential: XXXXXEngine Technologies
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Diesel Engine Thermal Efficiency & Exhaust Waste Heat
LPL Engine
0
20
40
60
80
100
Fuel
Ene
rgy
(kW
)
Fuel Energy, %
~ 8%
~ 22%
Brake Power
CoolantHeat Rej
EGR Cooler HR
ATAAC HR
ExhaustEnergy
~ 42%
~ 21%
~ 7%
HPL Engine
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
BrakePower
EGRHE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
BrakePower
EGRHE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGICooler CGI
BrakePower
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPF
CGICooler CGI
BrakePower
0
20
40
60
80
100
Fuel
Ene
rgy
(kW
)
Fuel Energy, %
~ 10%
~ 22%
Brake Power
CoolantHeat Rej
CGI Cooler HR
ATAAC HR
ExhaustEnergy
~ 42%
~ 21%
~ 5%
Roughly half of the lost fuel energy is carried in the exhaust streams
Caterpillar Confidential: XXXXXEngine Technologies
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0
20
40
60
80
100
Fuel
Ene
rgy,
%)
Diesel Engine Thermal Efficiency & Exhaust Waste HeatHTCD 50% OTE Program –
Analysis Results
15%
15%
25%
45.0%OTE
Research45% OTEEngine
HE NoxA/T
ImprovedAir System
Reduced
Heat
RejectionTurbo-
compound
CombustionSystem
Optimization
BrakePower
CoolantHeat Rej
ATAAC HR
ExhaustEnergy
ATAIC HREGR HR
45.2%OTE
47.0%OTE
47.3%OTE
48.2%OTE
50.5%OTE
26%
9%
14%
Waste heat recovery from the exhaust streams will be essential to achieving
50 -
55% thermal efficiency
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Challenges to Efficient Exhaust Waste Heat Recovery
Turbocompound
TechnologyChallenges for2010 & Beyond
Bottoming Cycles
Turbo EfficienciesTransmission Aftertreatment BP
Cycle EfficienciesPackagingTransmissionAftertreatmentinlet temperatures
Development Needs
Turbo Efficiencies
Electrical Machines
Combustion
Aftertreatment
Compact Heat Exchangers
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AGENDA
Overview - Engine Thermal Efficiency and Waste Heat Recovery
EWHR Program Objectives, Timeline, Scope
Technical Developments
Summary and Conclusions
Caterpillar Confidential: XXXXXEngine Technologies
Caterpillar Non-Confidential
Program Objective
Develop components, technologies, and methods to recover energy lost in the exhaust processes
of an internal combustion engine and
utilize that energy to improve engine thermal efficiency by 10% (i.e. from ~ 42% to ~46% thermal efficiency)
No increase in emissions
No reduction in power density
Compatible with anticipated aftertreatment
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Phase 2
20062005
DefineRoadmap
2007 2008 2009
Phase 1
Validateroadmap
2010 2011
Phase 3 Phase 4Refine Recipe Final System Demo
Phase 5
Mid-Program System Demo
We are here
Phase 3 Objective: Demonstration of significant progress (+ 5-10%) in system thermal efficiency improvement via testing/analysis of prototype components. This will include an on-engine system demonstration of prototype hardware.
Program Phases Per Contract
Program Timeline
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Program scope revised to include investigation of LPL & HPL
solutions
LPL CGI SystemAmbient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGICooler CGI
BrakePower
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPF
CGICooler CGI
BrakePower
Solutions compatible w/ production engines –transferable technologies
–
Baseline -
2007 C15 on-highway engine with LPL CGI system
HECC HPL EGR SystemAmbient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
BrakePower
EGRHE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
BrakePower
EGRHE
Solutions compatible with future engines –technologies for HECC solutions
–
HPL or HPL-LPL advantageous in some scenarios
Program Scope
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AGENDA
Overview - Engine Thermal Efficiency and Waste Heat Recovery
EWHR Program Objectives, Timeline, Scope
Technical Developments
Summary and Conclusions
Caterpillar Confidential: XXXXXEngine Technologies
Caterpillar Non-Confidential
Technical Developments –
Proposed System
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGICooler CGI
BrakePower
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPF
CGICooler CGI
BrakePower
Port Insul.(0.5%)
Piping(0.5%)
Intercooling(1.3%)
I/C
HP Turbine(2.0%)
LP Turbine(1.0%)Compressors
(0.7%)* Turbocompound or bottoming cycle: supplements engine power via electrical or mechanical connection to flywheel
Stack Recovery*(4.0%)
An integrated system solution to waste heat recovery
Strategy OptimizationEn
ergy
tran
smiss
ion
Caterpillar Engine Technologies
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Early in program:•
2010 A/T backpressure levels not known with certainty•
Turbocompound known to be negatively affected by backpressure
Forced consideration of “backpressure insensitive”
solutionsAmbient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGI
BrakePower
HE
Turb Comp
AmbientStack
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
CGI
BrakePower
HE
TurbTurb Comp
AmbientStack
Phase 1 Proposed SolutionOpen Air Brayton
Cycle
Performance Objective CAN be met with Brayton
Cycle Solution and supporting technologies
Packaging???
Technical Developments –
Stack Energy Recovery
2.8%
3.5%
4.3%4.0%
3.0%
2.3%
0
500
1000
1500
2000
2500
3000
500 1000 1500 2000En
gine
Loa
dEngine Speed
2.8%
3.5%
4.3%4.0%
3.0%
2.3%
0
500
1000
1500
2000
2500
3000
500 1000 1500 2000En
gine
Loa
dEngine Speed
Phase 2 Engine SimulationsBSFC Benefit of Brayton
on C15
Brayton
cycle w/ high efficiencyturbomachinery & insulated exhaust ports
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Microchannel manufacturing technology
Concept design: 1.5 ft3
core vol.Preliminary estimate: ~ 0.5 -
1 ft3
core
2 ft3
core vol.Caterpillar technology
Primary Surface technology
Phase 2Heat Exchanger Technology Evaluations
At end of Phase 2, no line of sight to a HE core smaller than
1.5 –
2.0 ft3
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGI
BrakePower
HE
Turb Comp
AmbientStack
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
CGI
BrakePower
HE
TurbTurb Comp
AmbientStack
Phase 1 Proposed SolutionOpen Air Brayton
Cycle
Packaging???
Technical Developments –
Stack Energy Recovery
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Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
CGI
BrakePower
HE
Turb Comp
AmbientStack
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
CGI
BrakePower
HE
TurbTurb Comp
AmbientStack
Packaging???
Phase 2 Packaging Studies with 1 ft3
heat exchanger core
Even at 1 ft3
core volume, system packaging is challenge
Technical Developments –
Stack Energy RecoveryPhase 1 Proposed Solution
Open Air Brayton
Cycle
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Technical Developments –
Stack Energy RecoveryElectric Turbocompound
Gen1 – Caterpillar / DOE 2001-2004 Development Program–
Approach –
Turbocompound function integrated into engine turbo–
Specification –
40kw @ 60krpm in generating mode
Measured Turbo Shaft Generator Power and Torque
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
25000 30000 35000 40000 45000 50000 55000 60000 65000
Turbo Shaft Speed rpm
Gen
erat
or P
ower
W
0
10
20
30
40
50
60
70
80
90
100
Elecronics O/ P pow er (W)
% Torque
–
Results•
Excellent stability of rotor / shaft system•
Generated 44kw at 59krpm–
Turbo generator short of efficiency target –
Heating problems –
powers above 15kw limited to 30-60sec runtime
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Technical Developments –
Stack Energy Recovery
Gen2 – Concept design collaboration with consultant–
Specification: 20-25kw power generation–
Two design options to be evaluated•
‘Between-the-wheels’
option•
‘In-front-of-compressor’
option–
Thermal, stress, rotordynamic
analysis to evaluate options–
Scheduled completion: 30Oct08Flywheel Motor/GeneratorHE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
EGR
BrakePower
I/C Elec
tric
al P
owe
r
GEN.
Flywheel Motor/GeneratorHE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
EGR
BrakePower
I/C Elec
tric
al P
owe
r
GEN.GEN.
HE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP Turb
DPF
EGR
BrakePower
I/C Elec
tric
al P
ower
Flywheel Motor/Generator
GEN.
HE
Ambient
Stack
Engine C15
A/C
LP Comp
HP Comp
LP Turb
HP TurbHP Turb
DPFDPF
EGR
BrakePower
I/C Elec
tric
al P
ower
Flywheel Motor/Generator
GEN.GEN.
Electric Turbocompound
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Technical Developments –
HP Turbine
Port Insul.(0.5%)
Piping(0.5%)
Intercooling(1.3%)
HP Turbine(2.0%)
LP Turbine(1.0%)Compressors
(0.7%)
Stack Recovery(4.0%)
Strategy Optimization
+2% Thermal Efficiency Requires +10% Turbine Stage Efficiency
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/C
Baseline2%
Target +10%
Turb
ine-M
ech
Effic
iency
, T-S
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/C
Baseline2%
Target +10%
Turb
ine-M
ech
Effic
iency
, T-S
TechnologiesRND – radial, nozzled, divided turbineMixed Flow Turbine
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Nozzled / Divided Turbine vs Production
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/CTu
rbin
e-M
ech
Effic
ienc
y, T
-S
Baseline
RND Measured
Target
2%
Nozzled / Divided Turbine vs Production
Turb
ine-M
ech
Effic
iency
, T-S
RND Optimized
Nozzled / Divided Turbine vs Production
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/CTu
rbin
e-M
ech
Effic
ienc
y, T
-S
Baseline
RND Measured
Target
2%
Nozzled / Divided Turbine vs Production
Turb
ine-M
ech
Effic
iency
, T-S
RND Optimized
Technical Developments –
HP Turbine
Port Insul.(0.5%)
Piping(0.5%)
Intercooling(1.3%)
HP Turbine(2.0%)
LP Turbine(1.0%)Compressors
(0.7%)
Stack Recovery(4.0%)
Strategy Optimization
Majority of exhaust energy isentering turbine in this region
Shift efficiencypeak
Gap
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Nozzled / Divided Turbine vs Production
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/CTu
rbin
e-M
ech
Effic
ienc
y, T
-S
Baseline
RND Measured
Target
2%
Nozzled / Divided Turbine vs Production
Turb
ine-M
ech
Effic
iency
, T-S
RND Optimized
Nozzled / Divided Turbine vs Production
0.680
0.700
0.720
0.740
0.760
0.780
0.800
0.820
0.840
0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/CTu
rbin
e-M
ech
Effic
ienc
y, T
-S
Baseline
RND Measured
Target
2%
Nozzled / Divided Turbine vs Production
Turb
ine-M
ech
Effic
iency
, T-S
RND Optimized
Technical Developments –
HP Turbine
Port Insul.(0.5%)
Piping(0.5%)
Intercooling(1.3%)
HP Turbine(2.0%)
LP Turbine(1.0%)Compressors
(0.7%)
Stack Recovery(4.0%)
Strategy OptimizationNew Target
Shifting peak efficiency –mixed flow turbine
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Technical Developments –
HP TurbineMixed Flow Turbine
radial mixed flowradial mixed flow
Gen1 wheel designed / procured / tested
Gen1 missed target performance:Over-aggressive design
–
Desire to clearly demo efficiency shift
First use of codes for mixed flow–
Calibration required
MF Turbine vs 2007 Production HP
0.62
0.64
0.66
0.68
0.7
0.72
0.74
0.76
0.5 0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/C
Turb
-Mec
h Ef
f, T-
S (%
)
Production Radial – Data
Mixed Flow – Gen1 Data
Target – Nozzleless Mixed Flow
Turb
ine-
Mec
h Ef
f. T-
S
MF Turbine vs 2007 Production HP
0.62
0.64
0.66
0.68
0.7
0.72
0.74
0.76
0.5 0.55 0.6 0.65 0.7 0.75 0.8
Velocity Ratio, U/C
Turb
-Mec
h Ef
f, T-
S (%
)
Production Radial – Data
Mixed Flow – Gen1 Data
Target – Nozzleless Mixed Flow
Turb
ine-
Mec
h Ef
f. T-
S
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Technical Developments –
HP Turbine
Gen2 wheel designed / analyzed–
Gen1 lessons used to optimize design
Mixed Flow Turbine
Gen2Gen1MF Turbine vs 2007 Production HP
0.62
0.64
0.66
0.68
0.7
0.72
0.74
0.76
0.5 0.55 0.6 0.65 0.7 0.75 0.8Velocity Ratio, U/C
Turb
-Mec
h Ef
f, T-
S (%
)
Production Radial Data
Mixed Flow – Gen1 Data
Gen2 Mixed Flow - Predicted
Turb
ine-
Mec
h Ef
f. T-
S
MF Turbine vs 2007 Production HP
0.62
0.64
0.66
0.68
0.7
0.72
0.74
0.76
0.5 0.55 0.6 0.65 0.7 0.75 0.8Velocity Ratio, U/C
Turb
-Mec
h Ef
f, T-
S (%
)
Production Radial Data
Mixed Flow – Gen1 Data
Gen2 Mixed Flow - Predicted
Turb
ine-
Mec
h Ef
f. T-
S
–
6-8% improvement in efficiency predicted vs
Gen1 over range of interest
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Brayton
CycleSystem Capability Evaluation
HE
Ambient
Stack
Engine C15
A/C
Comp Turb
DPF
EGR
BrakePower
Turb Comp
Elec
tric
al
Pow
er
Flywheel Motor/Generator
GEN.
Brayton Cycle
Ambient Ambient
HE
Ambient
Stack
Engine C15
A/C
Comp TurbTurb
DPFDPF
EGR
BrakePower
Turb Comp
Elec
tric
al
Pow
er
Flywheel Motor/Generator
GEN.GEN.
Brayton Cycle
Ambient Ambient
Assumptions:–
Brayton
turbo efficiencies 80%–
Single stage for packaging–
Heat exchanger: 90% effectiveness–
Transmission Efficiency: 90%
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
20.0 25.0 30.0 35.0 40.0 45.0
EGR Flow Rate (%)
BSF
C Im
prov
emen
t (%
)
Packaging: Excellent–
Heat Exchanger:
0.25 ft3
core–
Turbo:
~ 2”
compressor
Performance: Low-Moderate–
At 20 -
40% EGR: + ~2 -
4% w/ 80% turbomachinery+ ~1.5 -
2.5% w/ 74% turbomachinery
Technical Developments –
HECC HPL EGR Waste Heat Recovery
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Rankine
CycleSystem Capability Evaluation
SH
Ambient
Stack
Engine C15
A/C
Comp Turb
DPF
EGR
BrakePower
TurbPump
Ele
ctri
cal
Pow
er
Flywheel Motor/Generator
GEN.
Rankine Cycle
EV
CondRC
SH
Ambient
Stack
Engine C15
A/C
Comp TurbTurb
DPFDPF
EGR
BrakePower
TurbTurbPumpPump
Ele
ctri
cal
Pow
er
Flywheel Motor/Generator
GEN.GEN.
Rankine Cycle
EV
CondCondRCRC
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
20 25 30 35 40 45
% EGR
BSF
C Im
prov
emen
t (%
)
Packaging: Challenge–
Multiple heat exchangers
Performance: Moderate-Good–
+ 3-6% depending on EGR rates
660degC
680degC
Exhaust temp640degC
Assumptions:–
Turbine efficiency 80%–
Pump efficiency 65%–
R245fa working fluid–
Transmission Efficiency: 90%
Technical Developments –
HECC HPL EGR Waste Heat Recovery
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AGENDA
Overview - Engine Thermal Efficiency and Waste Heat Recovery
EWHR Program Objectives, Timeline, Scope
Technical Developments
Summary and Conclusions
Caterpillar Confidential: XXXXXEngine Technologies
Caterpillar Non-Confidential
Summary
Significant progress made toward program objectives:
With LPL CGI, turbocompound + high efficiency turbos provides +4% BSFC w/ 20kPa aftertreatment backpressure.
Progress on supporting technologies, especially turbine technologies, suggests performance target can be met
Waste heat recovery for future HECC engine solutions prompts consideration of HPL and HPL-LPL EGR configurations
–
Turbocompound still effective for stack recovery. Benefit dependent on aftertreatment backpressure, required EGR rates
–
Brayton
cycle offers moderate benefit for HPL loop heat recovery
–
Rankine
cycle offers significant benefit for HPL loop heat recovery
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Acknowledgements
Turbomachinery design consulting, component procurement and integration.
Turbomachinery design consulting and optimization.
Turbomachinery design consulting and optimization.
Caterpillar Thanks:
Electric turbocompound design consulting
Honeywell
ConceptsNREC
Turbo Solutions
Barber-Nichols Inc.
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Acknowledgements
• Department of Energy• Gurpreet
Singh
• John Fairbanks
• DOE National Energy Technology Laboratory• Ralph Nine• Carl Maronde
Caterpillar Thanks:
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