An Engine System Approach to Exhaust Waste Heat · PDF fileAn Engine System Approach to Exhaust Waste Heat Recovery ... HE Motor/Generator Ambient Stack Engine C15 A/C ... An Engine

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



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%



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



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



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



AGENDA







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



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



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



AGENDA







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



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???


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



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???





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


Stack Energy RecoveryPhase 1 Proposed Solution

Open Air Brayton

Cycle






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





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


GEN.GEN.

Electric Turbocompound




HP Turbine

Port Insul.(0.5%)

Piping(0.5%)

Intercooling(1.3%)

HP Turbine(2.0%)


(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



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%


Turb

ine-M

ech

Effic

iency

, T-S

RND Optimized


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


rbin

e-M

ech

Effic

ienc

y, T

-S

Baseline

RND Measured

Target

2%


Turb

ine-M

ech

Effic

iency

, T-S

RND Optimized


HP Turbine

Port Insul.(0.5%)

Piping(0.5%)

Intercooling(1.3%)

HP Turbine(2.0%)


(0.7%)


Strategy Optimization

Majority of exhaust energy isentering turbine in this region

Shift efficiencypeak

Gap




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


rbin

e-M

ech

Effic

ienc

y, T

-S

Baseline

RND Measured

Target

2%


Turb

ine-M

ech

Effic

iency

, T-S

RND Optimized


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


rbin

e-M

ech

Effic

ienc

y, T

-S

Baseline

RND Measured

Target

2%


Turb

ine-M

ech

Effic

iency

, T-S

RND Optimized


HP Turbine

Port Insul.(0.5%)

Piping(0.5%)

Intercooling(1.3%)

HP Turbine(2.0%)


(0.7%)


Strategy OptimizationNew Target

Shifting peak efficiency –mixed flow turbine




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


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


Target – Nozzleless Mixed Flow

Turb

ine-

Mec

h Ef

f. T-

S




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


Gen2 Mixed Flow - Predicted

Turb

ine-

Mec

h Ef

f. T-

S


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


Gen2 Mixed Flow - Predicted

Turb

ine-

Mec

h Ef

f. T-

S

–

6-8% improvement in efficiency predicted vs

Gen1 over range of interest



Brayton

CycleSystem Capability Evaluation

HE

Ambient

Stack

Engine C15

A/C

Comp Turb

DPF

EGR

BrakePower

Turb Comp

Elec

tric

al

Pow

er


GEN.

Brayton Cycle

Ambient Ambient

HE

Ambient

Stack

Engine C15

A/C

Comp TurbTurb

DPFDPF

EGR

BrakePower

Turb Comp

Elec

tric

al

Pow

er


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


HECC HPL EGR Waste Heat Recovery



Rankine

CycleSystem Capability Evaluation

SH

Ambient

Stack

Engine C15

A/C

Comp Turb

DPF

EGR

BrakePower

TurbPump

Ele

ctri

cal

Pow

er


GEN.

Rankine Cycle

EV

CondRC

SH

Ambient

Stack

Engine C15

A/C

Comp TurbTurb

DPFDPF

EGR

BrakePower

TurbTurbPumpPump

Ele

ctri

cal

Pow

er


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%


HECC HPL EGR Waste Heat Recovery



AGENDA







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



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.



Acknowledgements

• Department of Energy• Gurpreet

Singh

• John Fairbanks

• DOE National Energy Technology Laboratory• Ralph Nine• Carl Maronde

Caterpillar Thanks:



Documents

An Engine System Approach to Exhaust Waste Heat · PDF fileAn Engine System Approach to Exhaust Waste Heat Recovery ... HE Motor/Generator Ambient Stack Engine C15 A/C ... An Engine