solid oxide fuel cell system development - national … library/events/2001/seca...solid oxide fuel...
TRANSCRIPT
Solid Oxide Fuel CellSystem Development
Nguyen Minh
2nd Solid State Energy Conversion Alliance WorkshopMarch 29-30, 2001
Arlington, VA
2ndSECA Workshop.ppt- 2
SimplifiedSimplified SOFC System & Components SOFC System & Components
High-T Heat Exchangers
Valves
Controllers
Blowers
Sensors
Thermal Management
AirManagement
Air
FuelProcessor
Fuel
ProcessExhaust
Solid OxideFuel Cell Stack
DC Power
AnodeExit
CathodeExit
CathodeInlet
AnodeInlet
SOFCStack
SOFCFuel Cell
CPOX Fuel Processor
Gas TurbineP
owe
r
Turbine Inlet
Microturbine
Turbo-Compressor
2ndSECA Workshop.ppt- 3
Heat Transfer/Thermal ManagementHeat Transfer/Thermal Management
• Extensive experience withthermal management ofcomplex systems
• Broad spectrum of heatexchanger products
• Thermal managementsystems for a wide range ofoperating environments
• Extensive experience withthermal management ofcomplex systems
• Broad spectrum of heatexchanger products
• Thermal managementsystems for a wide range ofoperating environments
F22 PrimaryHeat Exchanger
CommercialRecuperators
Si3N4 Ceramic HeatExchanger
757-300 RRPrecooler
2ndSECA Workshop.ppt- 4
TurbomachineryTurbomachinery
• Expert knowledge in positivedisplacement and dynamicpumps, compressors, andturbines
• Wide range ofturbomachinery products
• Development ofturbocompressor for PEMFCsystems
• Expert knowledge in positivedisplacement and dynamicpumps, compressors, andturbines
• Wide range ofturbomachinery products
• Development ofturbocompressor for PEMFCsystems
RAH-66 Fan
50 kWTurbogenerator
Trident GasHydraulic Assembly
Turbopump
PEMFC Turbocompressor
2ndSECA Workshop.ppt- 5
Controls and SensorsControls and Sensors
• Controls– Model-base control and
optimization algorithmsincluding Fuel Cell DynamicsComponent Library
– Rapid prototyping– Load following control
system for PEMFC systems
• Sensors– Relative humidity– Mass air flow– Hydrogen– Carbon monoxide
• Controls– Model-base control and
optimization algorithmsincluding Fuel Cell DynamicsComponent Library
– Rapid prototyping– Load following control
system for PEMFC systems
• Sensors– Relative humidity– Mass air flow– Hydrogen– Carbon monoxideHeater
SensorSensor
0 0.01 in.
Top view and cross section ofMass Air Flow Sensor
Hydrogen Sensor
Control Schematic
2ndSECA Workshop.ppt- 6
System Development Approach System Development Approach
• Low-cost fabrication processes and materialsalong with compact, lightweight componentdesigns– SOFC: Tape calendering fabrication process, stack designs
incorporating thin-electrolyte cells and thin-foil metallicinterconnects
– Fuel processor: Catalytic partial oxidation (CPOX)
• Component designs based on systemrequirements and other design methodologies(e.g., design-for manufacturing, design-to-cost)
• Focus on lessons learned from small (50 W toseveral kW) system operation
2ndSECA Workshop.ppt- 7
SOFC Stack MetricsSOFC Stack Metrics
• Fabrication and operationof multi-cell stack ofvarious sizes (up to kWsize)
• 800°C operation atambient pressure andup to 3 atm
• Thermal cycling
• Start-up and shut-down
• Power density:– 0.6 W / cm² with hydrogen– 0.4 W / cm² with syngas
from JP-8
• Fabrication and operationof multi-cell stack ofvarious sizes (up to kWsize)
• 800°C operation atambient pressure andup to 3 atm
• Thermal cycling
• Start-up and shut-down
• Power density:– 0.6 W / cm² with hydrogen– 0.4 W / cm² with syngas
from JP-8
30 Ce ll Sta ck , 4"x4" Footprint 800°C
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
0 .000 0.100 0.200 0.300 0.400 0.500 0.600 0.700Curr ent Density (A/cm ²)
Vo
ltag
e (V
)
0
200
400
600
800
1000
1200
Po
wer
(W
)
Stack V oltage
Pow er
2ndSECA Workshop.ppt- 8
CPOX Performance MetricsCPOX Performance Metrics
• Duration: 700 hours to date
• Thermal cycles: 10
• Sulfur tolerance: 1000 ppmdibenzothiophene in JP-8
• Yield: 70-80% of LHV in JP-8
• Duration: 700 hours to date
• Thermal cycles: 10
• Sulfur tolerance: 1000 ppmdibenzothiophene in JP-8
• Yield: 70-80% of LHV in JP-8
0%
20%
40%
60%
80%
100%
0 40 80 120 160 200 240 280 320
Time (Hours)
Per
cen
t Y
ield
%
H2
COThermal Cycle
2ndSECA Workshop.ppt- 9
System Design MethodologySystem Design Methodology
• Propose Conceptual Design• Assume Components
• Model System
• Design Components• System Analysis
• Trade Studies
• Compare to Requirements
• Identify Gaps
Conceptual SystemDefinition
Technology Gaps
System Definition
TechnologyDevelopment
System Requirements Technology Base
2ndSECA Workshop.ppt- 10
Anode Fin
AlloyInterconnect
Cathode Fin
Single Cell
OxidantPassage
FuelPassage
Solid Oxide Fuel Cell Battery ChargerSolid Oxide Fuel Cell Battery Charger
Requirements– 7 kg– 500 W at 28 VDC– Operation on logistic
fuels (JP and diesel)
Requirements– 7 kg– 500 W at 28 VDC– Operation on logistic
fuels (JP and diesel)
2ndSECA Workshop.ppt- 11
System Weight OptimizationSystem Weight Optimization
• 500 W, 28 VDC output• Hydrogen utilization of 0.8
• Minimum weight at cellvoltage of 0.75 V
• 500 W, 28 VDC output• Hydrogen utilization of 0.8
• Minimum weight at cellvoltage of 0.75 V
0.4 0.5 0.6 0.7 0.8 0.90 0.1 0.2 0.3
2.5
2
1.5
1
0.5
0
Cell Voltage, V
Fu
el C
ell A
ssem
bly
Wei
gh
t, k
g 3
2.5
2
1.5
1
0.5
00.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9
Cell Voltage, V
Air
to
Air
Hea
t E
xch
ang
er W
eig
ht,
kg
Cell Voltage, V
0 0.90
Fu
el C
ell a
nd
Air
-to
-Air
Hea
t E
xch
ang
er W
eig
ht,
kg
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
+
2ndSECA Workshop.ppt- 12
CPOX/SOFC Integration - Key Parameters CPOX/SOFC Integration - Key Parameters
• Start-up and shut-down procedures
• Range of operating parameters
• Pressure drop
• Thermal management
• Transient characteristics
2ndSECA Workshop.ppt- 13
Integrated CPOX-SOFC OperationIntegrated CPOX-SOFC Operation
Air
FuelCPOX Reformate SOFC
CPOXOutput
17.3% H2
21.0% CO0.7% CO211.0% H2O50.0% N2
InputJP-8Air
Demonstration of multicell SOFC operation on JP-8 syngasDemonstration of multicell SOFC operation on JP-8 syngas
Module Operating on CPOX Productat 800°C
0
0.2
0.4
0.6
0.8
1
0.00 0.05 0.10 0.15 0.20 0.25 0.30
Current Density [A/cm²]
Vo
ltag
e (V
)
0.000
0.050
0.100
0.150
0.200
Po
we
r D
en
sity
[W
/cm
²]
V PD
2ndSECA Workshop.ppt- 14
System DemonstrationSystem Demonstration
• Demonstration of keycomponent integration– Integration of system
components, especiallyCPOX fuel processor andSOFC stack
• Operation characteristics– Startup– Thermal integration– Propane and JP-8 fuels
• Demonstration of keycomponent integration– Integration of system
components, especiallyCPOX fuel processor andSOFC stack
• Operation characteristics– Startup– Thermal integration– Propane and JP-8 fuels
2ndSECA Workshop.ppt- 15
Concluding RemarksConcluding Remarks
• Low-cost fabrication processes and materialsalong with compact, lightweight componentsdeveloped for SOFC systems
• Demonstration of component integration andoperation of small systems
• Near-term activities consistent with SECA plan