Numerical study on effects of hydrogen ejector on PEMFC performances

Abstract

The hydrogen ejector has been extensively researched due to its cost-effectiveness, durability, and energy efficiency. This study investigates the impact of hydrogen ejectors on the performance and water distribution of different types of flow field proton exchange membrane fuel cells (PEMFCs). The search results demonstrate that hydrogen ejectors can enhance performances and reduce the extent of water flooding in PEMFCs with various flow field designs. Moreover, it has been observed that the performance of PEMFCs with the hydrogen ejector is significantly enhanced as the operating voltage decreases. In addition, the performance and water distribution of serpentine flow field PEMFCs with hydrogen ejectors were investigated under different operating parameters, and the corresponding sensitivity of these parameters was quantitatively determined. Based on the simulation results, it was found that maintaining the anode relative humidity at 60 % and the cathode relative humidity at 20 % can achieve higher performances and reduce the extent of water flooding in PEMFCs with hydrogen ejectors. Through sensitivity analysis of each operating parameter, it is found that the operating pressure and cathode relative humidity have the greatest and least impact, respectively, on the performance of PEMFCs with a hydrogen ejector.