A system model of proton exchange membrane fuel cell for the study of the water/thermal management

Transcription

1 A system model of proton exchange membrane fuel cell for the study of the water/thermal management 4 th U.S. KOREA NanoForum April 26, 27 Sangseok Yu Environment and Energy Research Division Korea Institute of Machinery and Materials (KIMM)

2 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

3 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 Electrochemistry And Mass Transfer Water Transport Model Electrochemical Reaction Model A Comprehensive Model Capturing Multi-Disciplinary Physics

4 Dynamic System Model of PEMFC Tavg Average Cell temperature[k] AJ Current Input Controller Stoich. H2 Stoich. Cooling System Fuel Supplier Supplier Reformer Turbo Blower Cooling System Tha Thc PA PC Step Input Anode humidifier Humidifier humidifier Cathode Fuel Cell Stack Fuel Cell Stack Module VC Fuel Cell Potential[V] Power Gross Power Tc,i,p1 Load Input Data Plot Result [TProfile] From temp out_temp Scope

5 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 Evaluate Control Algorithms Evaluate Energy Savings Information Transfer 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

6 Control of Thermal Management System Coolant Temperature Control Optimal Coolant Temperature (K) Operating Criteria By Unit FC Model Current Density (A/cm 2 ) Fan Speed (rpm) Current Density (A/cm 2 ) Current Density Profile Time (sec) 6 % Reduction of Parasitic Loss & Improved 2% of System Efficiency by Control Algorithm Feedback Control Conventional Control Fan Speed Pump Speed (rpm) Net Power (W) Feedback Control Conventional Control Net Power Time (sec) Feedback Control Conventional Control Pump Speed Time (sec) Time (sec)

7 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.

8 On Going Works Integration and Optimization of 15 kw SOFC System Design Optimization of 25 kw MCFC Hybrid System Pre-Conv HEX Reformer CC HEX Cathode Stack HEX HEX HRSG WTS DS Vent Off gas Catalyti c Combus tor Heat MCFC stack Anode Steam Reform Fuel + er Water Cathode Exhau st T/C Anode SOFC C/V Comp Motor /Gen NG Water Turbine MODULE Turbin e Motor Co / Generat mp. or A Dynamic Model of 8 kw SUV Powered by PEMFC System Optimization of 1kW PEMFC RPG Hydrogen Supply Mdot_H2 [kg / s] Drv_dmd H2_press [atm] Hydrogen Supply Module Load Input Data Exhaust Off-gas Comp. Mixing Gas Add CH4 + Combustor Compressor P_dry_air Mdot_H2 Compr_Pwr Supply Module Controller rack position vehicle speed feedback braking Controller FUEL CELL Fuel Cell Stack Electric Motor Drivetrain Power Demand [KW] Motor trq output [rad/s] T motor T_shaft Motor_spd Electric Motor w_wheel w_shaft DRIVETRAIN Load Output Variables T wheel rear w wheel Brake Vehicle Speed VEHICLE DYNAMICS Blower Water Pump Humidifier Cathode Electrolyte Anode Fuel Processor WGS PrOx (LTS) ATR Turbine CH4+Water + Load Speed Variables Plot Electric Motor Plot Fuel Cell Plot Driveline Plot Vehicle Plot Speed Vehicle Dynamics Water Tank Exhaust City Water Water Tank

9 Thank you!!! 4th U.S. KOREA NanoForum