THREE-DIMENSIONAL CFD MODELING OF TUBULAR SOLID OXIDE FUEL CELLS WITH DIFFERENT FUELS

Solid oxide fuel cell (SOFC) technology has been of great interest over many years due to its flexibility in using different fuels including the fundamental fuel i.e. hydrogen, for its operation. Various computational and numerical models have been developed along with experimental work to evaluate the performance as well as to identify and overcome the problems faced in the development of SOFC's. In an attempt to achieve efficient operation with respect to design and combined thermal and electrochemical perspective, the main objective of the proposed study is to present a three-dimensional computational model which will serve as a framework for the analysis and optimization of SOFC's. A three-dimensional (3-D) model of a tubular SOFC is being developed to study the effect of temperature and electrolyte thickness variations on its performance. A commercial Computational Fluid Dynamics (CFD) software ANSYS-FLUENT was used for the development of the tubular model which incorporates an interactive 3-D electro-thermochemical fluid flow analysis. The particular model, after validation against experimental observations for selected benchmark cases, was demonstrated to be compatible for intermediate temperatures using hydrogen as the fuel. The performance of the model was analyzed by varying electrolyte thicknesses from 2-100 mu m. The same model was further evaluated using different fuels such as CH4 (methane) and CO (carbon monoxide), including the modeling of the reformation and water-gas shift reactions. The results were compared to other computationally less expensive, analytical and empirical models that could serve as basic models for future research on intermediate temperature SOFC's.