Transient heat transfer modeling of a solid oxide fuel cell operating with humidified hydrogen

This paper presents the development of a new transient heat transfer model of a planar solid oxide fuel cell (SOFC) operating with humidified hydrogen. The model is first validated with some benchmark test data and then used to simulate the transient behavior of the co- and counter-flow SOFCs at the heat-up and start-up stages. In addition, a parametric study including the effects of Reynolds number at the fuel channel inlet and excess air coefficient on the output parameters is conducted. The model predictions are found to be in very good agreement with the data published in the literature. The transient simulations show that counter-flow SOFC yields higher performance, e.g. power density and electrical efficiency, but it needs slightly more time to reach the steady-state conditions. The results of the parametric study point out that taking the Reynolds number low and excess air coefficient high gives higher electrical efficiencies for both of the configurations. For the given input data, it is found that the counter-flow configuration has a higher electrical efficiency for low Reynolds numbers, e.g. 0.67 and all possible excess air coefficients.