Nonisothermal modeling of polymer electrolyte fuel cells I. Experimental validation

A three-dimensional, nonisothermal model of polymer electrolyte fuel cells (PEFC) is applied to a 50 cm² cell under various humidity conditions and validated against experimental data of current distribution. In low-humidity operation, coupled modeling of water and heat management is essential as the current density distribution is mainly controlled by hydration of the polymer electrolyte, which is a strong function of temperature due to the water vapor saturation pressure increasing exponentially with temperature. Since these validation simulations involve several millions of computational grid points and hence are considered large-scale calculations, a parallel computational methodology has been employed to substantially reduce the computational time and relax the memory requirement. The model predictions compare well with the detailed experimental data over a wide range of humidity conditions at anode and cathode, and furthermore reveal the complex interplay of heat and water transport phenomena inside PEFC through extensive multidimensional contours of species concentration, temperature, and current density.