An open-source two-phase non-isothermal mathematical model of a polymer electrolyte membrane fuel cell

Abstract

A comprehensive open-source two-phase non-isothermal MEA model including the microporous layer and accounting for multi-step reaction kinetics for the ORR and HOR is developed for the first time. The model is integrated into openFCST, an open-source FEM based fuel cell simulation framework. All the significant non-isothermal effects such as anisotropic heat transport, irreversible and reversible heating due to electrochemical reactions, ohmic heating, heat of sorption and thermal osmosis are accounted for in the model. Accurate experimental data for capillary pressure-saturation relationships are reformulated and incorporated into a liquid water saturation transport equation. The model showed, for the first time, that thermal osmosis effects account for up to 15% water-crossover in membrane, and the heat of sorption can be as large as protonic ohmic heating. The model could accurately predict the performance drops corresponding to mass transport limitations due to presence of liquid water and ohmic losses due to membrane dry-out.