Optimization of channel structure for proton exchange membrane fuel cells based on a three‐dimensional two‐phase flow model

Abstract

The flow in the channel of the proton exchange membrane fuel cell (PEMFC) is very complicated, but important which determines the efficiency of mass transfer and water management and directly affects the performance of PEMFC. A three-dimensional nonisothermal two-phase flow model of PEMFC with a single straight channel is first established and verified through experiment. The polarization curves calculated by the model agreed well with the experimental data under two different anode and cathode platinum (Pt) loadings. Then, combined with the Nelder-Mead Simplex (NMS) method, the cross-sectional shape of the flow channel is further optimized. Considering the pumping power loss and output power of PEMFC, a trapezoidal section is finally obtained and the detailed flow characteristics are investigated. The optimization result indicates that the trapezoidal channel improved the uniformity of reactant distribution and reaction rate. At the same time, the trapezoidal channel can better remove the liquid water in the porous media. Thus, its performance is improved obviously compared with the original straight channel, especially at low operating voltage. For the optimal channel, the power density increases by 4.43% at the voltage of 0.5 V.