Numerical study on heat transfer characteristics and performance evaluation of PEMFC based on multiphase electrochemical model coupled with cooling channel

In this study, a three-dimensional multi-phase proton exchange membrane fuel cell (PEMFC) electrochemical model coupled with a cooling channel (CC) was developed, to comprehensively analyze the heat transfer characteristics. The membrane temperature, index of uniform temperature (IUT), net power, and the Nusselt number were applied to evaluate the heat transfer performance. The results indicate that a smaller IUT value achieves better PEMFC performance at close temperatures, and the best performance is achieved with a coolant inlet temperature of 343.15 K. Although increasing the coolant flow velocity improves the cooling effect, thereby enhancing PEMFC performance. However, it inevitably leads to an increase in parasitic power, resulting in a decrease in the output power of the PEMFC system. Moreover, with the coolant temperature difference less than 6K, PEMFC shows better performance when the coolant flow direction is the same as O2. On the contrary, with the coolant temperature difference greater than 6K, the coolant flow direction should be the same as H2 to ensure good performance. In addition, with the temperature difference between the coolant inlet and outlet of 10K, 6K, and 3K, respectively, the surface Nusselt number of wavy CC is 5.46%, 8.92%, and 18.71% higher than the straight CC, respectively.