A Matlab-Simulink Analysis of Hybrid SOFC Dynamic Behavior

Fuel cells are more and more used in hybrid systems with micro-turbines for electricity and heat delivery. Two types of fuel cells are mostly used for cogeneration: solid-oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC). Solid oxide fuel cells (SOFC) are operating at high temperatures that make them well suited for cogeneration process, but influence the entire system due to their dynamic character. The hybrid system requires a pre-reforming process in order to convert the fuels, such as natural gas, in a gas with a high hydrogen content for the electrochemically oxidation with air. In this paper the dynamic model of the SOFC and of the hybrid system is developed in Matlab-Simulink environment. The comprehensive model is based on the electrochemical and thermal equations and on the temperature dynamics. The response of the SOFC and of the hybrid system to the variation of fuel flow and other parameters is investigated.