CFD simulation of hot spot in PEM fuel cell with diverging and converging flow channels

Abstract

Hot spot formation is one of the most critical factors contributing to the membrane layer deterioration and, hence, fuel cell performance degradation. When local hot spot patches develop, the long-term endurance of a PEM fuel cell catalyst and membrane layer is dramatically reduced. The reactive flow gas distribution inside a PEM fuel cell with a 3-D gas diffusion layer has been investigated using divergent and convergent gas flow channels. COMSOL Multiphysics 4.4a was used for simulation studies. A three-dimensional gas flow channel for a single-phase, a non-isothermal simulation model of cathode side PEM fuel cells was created to investigate the impact of the local hot spot patch on the cathode side PEM fuel cells. The effect of local hot spot patches on the catalyst and membrane layer is investigated in this work, using a transient-state modeling approach. The conclusions have important implications for evaluating the internal reaction uniformity in the PEM fuel cell using divergent and convergent flow channels and developing a theoretical basis for evaluating local hot spot patches on the catalyst and membrane layer surface. Maximum surface temperature of the divergent flow channel was found to be 4% lower than that of the convergent flow channel. The studies aim to examine the possibility of altered variation of local hot spots on the catalyst and membrane layer due to changes in depth-dependent flow fields.