Analysis of the impact of flow field arrangement on the performance of PEMFC with zigzag-shaped channels

Abstract

Flow field configuration of a proton exchange membrane fuel cell (PEMFC) is crucial to its performance enhancement because it determines the distribution of reactants and reaction products. This paper numerically investigates a zigzag flow field with a contrary anode/cathode arrangement (ZFFCA). First, a three-dimensional numerical model is developed and validated against the published experimental data of a PEMFC that operates under low-humidity conditions. Then, the behavior of the contrary arrangement design is analyzed and compared with the zigzag parallel flow field (ZPFF) and straight parallel flow field (SPFF) designs. The model predictions show that the ZFFCA and ZPFF flow field designs provide more uniform distributions of oxygen, water content, temperature, and current density compared to the SPFF design, while the ZFFCA configuration is found to exhibit the most uniform distributions. More importantly, besides the enhanced transport along the flow direction in-between the underneath-land and underneath-channel regions in zigzag-shaped channels, the ZFFCA configuration is found to further reduce the mass transport resistance of reactants and boost up the heat/mass transfer rates. Additionally, the findings show that the positive effects of the ZFFCA configuration can further increase under higher relative humidity and larger operating pressure conditions, indicating that the ZFFCA design might be a more advanced option for the PEMFC stacks.