Dynamic Modeling and Experimental Evaluation of a High Temperature Polymer Electrolyte Membrane Fuel Cell System

Since 1990, the power generation market has shifted from large, centralized power plants to small, distributed engines to produce power near the point of consumption. The fuel cell is a prominent candidate for the small, distributed engines, despite the current barriers of reliability and cost. This research project evaluates the performance of a high temperature polymer electrolyte membrane fuel cell system.;This thesis presents the dynamic model of a fuel cell system featuring a thermally integrated fuel processor, a fuel cell stack with cathode recirculation, and a heat recovery unit. Each component was calibrated with a steady-state model and then connected to form a system. Parallel with developing the dynamic model, engineers installed and operated three fuel cell prototypes. To verify the model, this study compared the results from the dynamic model to the experimental data in two scenarios: a power sweep from 1.7 to 3.5 kW, and a change in burner from 7.5 to 15 kW. After the verification, this study then used the model to investigate the control of ATR temperature. Through these analyses, the project's objectives are to: Gain confidence the model accurately simulates the steady state and dynamic response of the integrated fuel cell system, and Use the dynamic model to test the control of ATR temperature.;This research found that the thermally integrated fuel processor together with the cathode recirculation could create a rise in the fuel processor temperature during rapid power increase. To stabilize the temperature, controlling the amount of air entering the cathode is necessary. This could necessitate the development of additional sensors and control methods for these integrated fuel cell systems in the future.