SM SECACORE 2001 Page 1

Solid Oxide Fuel Cell Auxiliary Power Unit :Status and challenges for automotive applications

Dr. S. MukerjeeDelphi Automotive Systems

SM SECACORE 2001 Page 2

IntroductionIntroduction

Delphi Automotive Systems is developing Solid Oxide Fuel Cell

(SOFC) technology for automotive applications - primarily as an

on-board Auxiliary Power Unit (APU).

Paradigm shift in the supply of electric power for transportation.

Highly efficient and low emissions.

Consistent with the increasing power demands in automobiles

in the new era of more comfort and safety along with

environmental friendliness.

SM SECACORE 2001

Fuel Cell APU for Gasoline CarsFuel Cell APU for Gasoline Cars

Today:

Tomorrow ?Alternator

Solid Oxide Fuel Cell APU

Why a SOFC APU?- The APU is not competing with the IC Engine but complements it.- Highly efficient generator providing power with the engine off- The SOFC utilizes simple reforming technology- Less stringent fuel requirements (uses CO as a fuel)

SM SECACORE 2001 Page 4

Solid Oxide Fuel Cell APU System OverviewSolid Oxide Fuel Cell APU System Overview

Auxiliary Power Unit (APU) Parts:SOFC Stack subsystem Fuel Reformer subsystemBalance of Plant (BoP)

Process Air SupplyThermal ManagementWaste Energy RecoveryPower Electronics / ControlsHVAC subsystem

Expected Customer Benefits:can supply electric power with

engine on or off, with high efficiencyand essentially zero emissions

permits operation of any electrical accessory

possible enabler for high power-consuming advancements (e.g., PVT)

HVAC System:42 vdc

Compressor

Power Electronics:System Controllers

and LiPo Battery

REF

OR

MER

PROCESS AIR

WASTEENERGY

RECOVERYUNITSTACK

Fuel

Exhaust

THERMAL MANAGEMENT

SM SECACORE 2001 Page 5

Solid Oxide Fuel Cell StackSolid Oxide Fuel Cell Stack

.♦ Stack developed by Global Thermoelectric

♦ Planar anode supported technology for high power density.

♦ Metallic interconnects for low cost.

♦ Compression seals for thermal cycling.

Source: Global Thermoelectric

SM SECACORE 2001 Page 6

SOFCSOFC““BOXERBOXER”” 15X4 Stack Plate15X4 Stack Plate

SM SECACORE 2001 Page 7

0.50

0.60

0.70

0.80

0.90

1.00

1.10

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80

Current Density, A/cm2

Volta

ge, V

olts

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Pow

er D

ensi

ty, W

/cm

2

800 - V 750 - V 700 - V 650 - V 600 - V800 - P 750 - P 700 - P 650 - P 600 - P

Single Cell Power Density with HydrogenSingle Cell Power Density with Hydrogen

Source: Global Thermoelectric

Fuel = hydrogen

SM SECACORE 2001 Page 8

SOFC Reformer PrototypeSOFC Reformer Prototype

Gasoline Reformer SubsystemAir / fuel Delivery

Subsystem

Capacity: 10 kWt ReformateCatalysts: Automotive DerivativeAir / Fuel Actuators: Standard AutomotiveStart-up time: < 10 minutes (to SOFC purity reformate)

SM SECACORE 2001 Page 9

Reformer CyclingReformer Cycling

SM SECACORE 2001 Page 10

Anode exhaust gas (750-800°C)

Process air (<100°C)Cathode air (~650°C)

Cathode exhaust air (750-800°C)

Exhaust air (~550°C)

SOFCSTACK

RCV

Reformer / Waste Heat Recovery IntegrationReformer / Waste Heat Recovery Integration

WASTE HEAT RECOVERY

SYSTEM

REFORMER SUBSYSTEM

Reformer Air (< 100 °C)

Gasoline (~ ambient T)

POx Reformate (H2 + CO + N2 + trace HCs)

(~800°C)

SM SECACORE 2001 Page 11

Layout of Vehicle APULayout of Vehicle APU

SM SECACORE 2001 Page 12

Technical ChallengesTechnical ChallengesTechnical Challenges

SOFC Has Many Challenges To Be Viable As An Automotive Technology:

Cost, Cost, Cost.

Power density

Higher efficiency.

High performance, low cost insulation.

Robust balance-of-plant components.

Fast startup and thermal cycling.

Automotive levels of robustness.

SM SECACORE 2001 Page 13

Competing Visions: Improve ICE or Replace it?Competing Visions: Improve ICE or Replace it?

Compressor

MultistagedReformer

Traction PEM FC

20 - 50 kW High Power / High EnergyBattery Pack

PowerElectronics

Electric Motor Drive

PEM FCEV = next generation EV(with smaller battery pack)

Micro-SOFC / Reformer0.5 - 5 kW

42 VGenerator

Internal Combustion Engine Mechanical

Drive

SOFC APU = high efficiency electricity +future vision for integration with ICE

FUEL

SM SECACORE 2001 Page 14

ConclusionsConclusionsConclusions

SOFC is an attractive automotive fuel cell technology.

It will enter the market as an APU - a paradigm shift in supply of electric power for transportation.

It is not likely to replace the ICE but will complement it.

It has other future mechanizations which support the trend toessentially zero toxic emissions and much reduced CO2 emissions

Delphi Automotive Systems with its partners are working toward bringing this key technology to market.