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Commercial Airplanes
Fuel Cell APUOverview
Presented at:SECA Annual Meeting
(Seattle, WA)
15 April, 2003
Dave DaggettProduct Development
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DLD03-15.ppt
Overview
• Boeing is looking for ways to cutemissions and fuel use
• Future fuel cells may fit well into ourfuture aircraft
• Apparent benefits look attractive
• There are hurdles, but no showstoppers
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DLD03-15.ppt
Fu
el(U
SG
al.)
per
100
pas
sen
ger
mile
s
0
1
2
3
4
5
6
0 10 20 30 40 50 60 70 80 90 100
Load Factor (%)
= Typical Load Factors
DD
99-1
5.xl
s
High-speedTrain
1) US average is 1.6 people per vehicle2) US commuter car is 1.2
per vehicle3) 1,500 nmi mission
Good
EuropeanInter-city train
"Average" 1996Vehicle(2)
Large SUVin City(1)
Airplanes are already efficient, butfurther improvement is
desired
AirplaneEnvelope (3)
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DLD03-15.ppt
APU Engine
LargeAirplane NOxEmissions at
Airport
We are looking for ways to cut NOxemissions
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DLD03-15.ppt
H2O
Cat
ho
de
O2O
O
H
O
C
HH2
An
od
e
CO
H HO
O OC
CO2 Ele
ctro
lyte
O-2ion
4e-
4e-
4e-
(O2 from air)
load
SOFC technology
Jet fuel is required, so SOFC may be right
Jet Fuel Reformer
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DLD03-15.ppt
0
2
4
6
8
10
12
14
16
1990 1995 2000 2005
Year
Fuel Cell System Weight (kg/kW)
Volume (Ltr/kW)
DLD
01-1
6.xl
s
Continued weight and size reductionprogress is needed
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DLD03-15.ppt
2000 2001 2002 2003 2004 2005
Year
Cap
ital
Co
st(M
illio
ns
$)
Turbine APU Price Range
DLD
01-1
6.xl
s
Large APU Retail Cost
Mass Produced Commercial Fuel CellPrice Range
Fuel cells need to become cost competitive
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DLD03-15.ppt
Present APU
Future 440 kW Fuel CellAPU Concept
SOFC APUs may replace turbine-poweredAPUs in commercial
aircraft
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DLD03-15.ppt
EnvironmentControlSystem
Motor
Battery
EnvironmentControlSystem
Motor
DC
AC
Engine
GearLift
Motor
GearLift
Motor
DC
AC
DC
AC Starter/Generator
Engine
Starter/Generator
Air
craf
tSy
stem
sA
ircr
aft
Syst
ems
Fuel CellAuxiliary
Power Unit
“More Electric” architecture is ideallysuited for fuel cell
APU
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DLD03-15.ppt
0
50
100
150
200
250
300
350
400
450
500
Gate Start Taxi Climb Cruise Descent Taxi
Mission Stage
AP
UL
oad
(kW
)
Environmental Control System Load
Total Electrical LoadMain Engine Start
Environmental Control System Load
A large “more-electric” airplane’s load islarge but relatively
constant
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DLD03-15.ppt
A hybrid SOFC APU concept is needed
HeatExchanger
HeatExchanger
AnodeDC
AC
ExhaustOverboard
JetFuel
Comp. Turbine
Air
Cathode
Pre-Reformer
Burner
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DLD03-15.ppt
APU Tail StructureFirewall
Future 2015Solid OxideFuel Cell
Fuel cell supporthardware
Hybrid SOFC APU installation concept
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DLD03-15.ppt
Boeing Commercial Airplanes creates sustainable profitablegrowth
with environmentally preferred products, processes,
andservices.
Animation of fuel cell APU
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DLD03-15.ppt
40-45% Efficient(Jet-A to electrical
during cruise)
Jet-A
1 litre
=
Future 2015SOFC APU
≈75% Efficient(Overall system at cruise)
0.6 litre
=Jet-A
40% lessfuel used
In-flight fuel saving opportunity
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DLD03-15.ppt
15% Efficient(over average operating cycle)
Typical Turbine-powered APU
Jet-A
1 litre
=
Fuel saving opportunity on the ground isvery attractive
Future 2015SOFC APU
60% Efficient(at std. sea-level conditions)
0.25 litre
=Jet-A
75% lessfuel used
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DLD03-15.ppt
?
Cost Pollution(at altitude)
Power Output
DLD
02-3
1
2015 SOFC APU?
Startup time
0
100
200
300
400
500
Fu
elC
ellP
erfo
rman
ce(%
of
turb
ine) 4000
Weight
RangeOf
Uncertainty
Fuel efficiency
Cruise
Ground
Overall, FCAPU looks to be beneficial
Turbine APU Baseline
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DLD03-15.ppt
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1990 1995 2000 2005 2010 2015
Year
Sta
ckP
ow
erD
ensi
ty(k
W/k
g)
DLD
02-3
8.xl
sDemonstrated
Latest Designs
Fuel Cell APURequirement Estimate
Fuel cell stack power density needs to beat least 1kW/kg
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DLD03-15.ppt
Summary
• Fuel cells may dramatically cut emissionsand fuel use for
aircraft
• Future MEA airplanes will be ideally suitedfor fuel cells
• Technology still needs to mature
• Good business case can be made
• We need to “work together” to make ithappen
