In order to optimize the performance of the trapezoidal flow channel proton exchange membrane fuel cell (PEMFC), this study used the topline/baseline bottom width of the trapezoidal flow channel as design variables to establish a three-dimensional multiphase trapezoidal flow channel PEMFC model. The PEMFC with rectangular straight channel was used as the basic model for comparative analysis. Taking the net power output as the objective function, the Kriging surrogate model was used to completely predict the analysis domain and form the response surface, the results showed that the response surface function constructed by the Kriging surrogate model had high accuracy. Finally, a wide and short optimal trapezoidal flow channel structure was obtained by genetic algorithm. It is found that the baseline width of the trapezoidal flow channel has a greater impact on the net power output. The increase of the baseline width can promote the downward diffusion of oxygen and increase the current density. When the voltage was 0.5 V, compared with the basic model, the net power output of the optimal model increased by 20.90%. It is also found that on the cathode side, the molar concentration of oxygen under the flow channel is higher than that under the land, and the molar concentration of oxygen gradually decreases along the flow direction of the reactants. Along the reactant flow direction and the vertical direction, the oxygen concentration gradient of the optimal model is lower than that of the basic model, and the oxygen distribution of the optimal model is more uniform. In the cathode diffusion layer and catalyst layer, the average molar concentration of oxygen in the optimal model is higher than that in the basic model. © 2022 Chin. Soc. for Elec. Eng.
