A system model of proton exchange membrane
fuel cell for the study of the water/thermal management
4th U.S. – KOREA NanoForum
April 26, 2007
Sangseok Yu
Environment and Energy Research Division
Korea Institute of Machinery and Materials (KIMM)
4th U.S. – KOREA NanoForum
Motivation and Objective
Motivation
A Need for Investigation of the PEMFC System Performance over Various
Parameters such as Material Parameters, Design Parameters, and Operating
Parameters
A Need to Develop a Multi-Purpose Model for the Investigation of PEMFC System
Based on Theoretical Understanding
Objective
To Develop High Fidelity Simulation Model for the Investigation of PEMFC
Performance with Excellent Computational Efficiency
To Find the Proper Methodology to Evaluate PEMFC System Performance
To Optimize Operating Conditions of the PEMFC System by the Simulation Model
4th U.S. – KOREA NanoForum
Multi-disciplinary Physics of Unit PEMFC
Heat Transfer Physics
-Conduction and Convection
Multi-Disciplinary Physics
Of PEMFC
Gas Diffusion Layer with
Catalyst Layer
Molecular Structure
Of Nafion Membrane
Water Transport Model
Electrochemistry
And Mass Transfer
A Comprehensive Model
Capturing Multi-Disciplinary Physics
Electrochemical Reaction Model
4th U.S. – KOREA NanoForum
Dynamic System Model of PEMFC
Tavg
Average Cell temperature[K]
AJ
Current
Step Input
Turbo
Blower-C-
Controller
Input
Anode
Tha
Cooling
Cooling
System
System
-CStoich. H2
-C-
Fuel
Supplier
0
VC
Fuel Cell Potential[V]
humidifier
humidifier
Humidifier
-CThc
PA
-C-
Cathode
Power
Gross Power
-CPC
Fuel Cell Stack
Reformer
Air
Tc,i,p1
Supplier
Fuel Cell Stack Module
Stoich. Air
Load
Input Data
Plot
Result
[TProfile]
From
temp
Scope
out_temp
4th U.S. – KOREA NanoForum
Systematic Analysis of PEMFC Performance
Setup Technical Challenges
… Thermal Management
… Water Management
… System Integration
Transient System Model
• Capability: Transient Performance Study of Fuel
Cell System
• Limitation: Lumped Heat Transfer
Information
Transfer
Evaluate Control Algorithms
Evaluate Energy Savings
Comprehensive MD Model
• Capability: Unit Fuel Cell Performance over
Various Conditions
• Limitation: Long Computational Time
Optimize Design Parameters
Offers Operating Criteria
Unit PEMFC Study
… Design Optimization
… Intuition to Operating Philosophy
PEMFC System Study
… Operating Strategy Optimization
… BOP Components Optimization
… System Integrations
4th U.S. – KOREA NanoForum
Control of Thermal Management System
Coolant Temperature Control
9 10
4
6 10
4
3 10
4
Feedback Control
Conventional Control
1
2
Current Density (A/cm )
1.2
0.6
0.4
Current Density Profile
0.2
0
0
200
400
600
800
1000
1200
Net Power
0
0
1400
200
400
600
800
1000
1200
1400
Time (sec)
Time (sec)
348
346
60 % Reduction of Parasitic Loss &
Improved 2% of System Efficiency by Control Algorithm
344
342
340
0.5
1
1.5
4000
2500
2
Current Density (A/cm )
Feedback Control
Conventional Control
Feedback Control
Conventional Control
2
2000
Pump Speed (rpm)
0
Fan Speed (rpm)
Optimal Coolant Temperature (K)
350
Net Power (W)
Operating Criteria By
Unit FC Model
0.8
1500
1000
Fan Speed
500
0
0
200
400
600
800
Time (sec)
1000
1200
1400
3000
2000
Pump Speed
1000
0
0
200
400
600
800
1000
1200
1400
Time (sec)
4th U.S. – KOREA NanoForum
Conclusion
A systematic analysis has been suggested to
achieve the efficient numerical computation with
high fidelity.
A comprehensive multi-dimensional model
determines the operating criteria of large active
area unit PEMFC with water cooling system.
A dynamic system model of PEMFC evaluates
control algorithms for supporting the operating
criteria.
4th U.S. – KOREA NanoForum
On Going Works
Integration and Optimization of 150 kW SOFC System
Pre-Conv
Design Optimization of 250 kW MCFC Hybrid System
HEX
Heat
HRSG
Vent
HEX
Reformer
HEX
WTS
Catalyti
c
Combus
tor
DS
Cathode
CC
MCFC
stack
Anode
Off
gas
HEX
Steam
Reform
er
Cathode
Fuel +
Water
Exhau
st
Air
Stack
Anode
SOFC
T/C
Water
Motor
/Gen
Comp
Motor
/
Generat
or
Co
mp.
Turbin
e
Air Turbine
MODULE
NG
C/V
Air
Air
A Dynamic Model of 80 kW SUV Powered by PEMFC
System Optimization of 1kW PEMFC RPG
Add CH4 + Air
Hydrogen Supply
Drv_dmd
Mdot_H2 [kg / s]
Exhaust
LoadInput Data
H2_press [atm]
Mixing
Gas
Off-gas
Combustor
Comp.
Hydrogen SupplyModule
Electric Motor
Drivetrain
LoadOutput Variables
Humidifier
Motor trq output [rad/s]
Compr_Pwr
Tmotor
T_shaft
Motor_spd
FUELCELL
Air SupplyModule
Fuel Cell
Stack
Controller
Electric Motor
w_wheel
w_shaft
Twheel rear
w wheel
Air
Blower
Anode
Anode
Power Demand [KW]
Cathode
Cathode
Mdot_H2
P_dry_air
Electrolyte
Compressor
Turbine
Fuel Processor
rack position
Brake
braking
VehicleSpeed
PrOx
Water Pump
Controller
LoadSpeedVariables
CH4+Water
+Air
DRIVETRAIN
vehicle speed feedback
VEHICLEDYNAMICS
Plot Fuel Cell
Plot ElectricMotor
Plot Driveline
Plot Vehicle
Plot Speed
WGS
(LTS)
ATR
Vehicle
Dynamics
Water Tank
City Water
Exhaust
Water Tank
4th U.S. – KOREA NanoForum
Thank you !!!
4th U.S. – KOREA NanoForum