Water management in a self-humidifying PEM fuel cell system by exhaust gas recirculation

Efficiency and durability of proton exchange membrane fuel cell (PEMFC) are compromised by drying of the membrane and by water flooding. This paper introduces a novel water management strategy by exhaust gas recirculation (EGR). The PEM fuel cell system with cathode EGR has a simpler structure and operates at lower cost than the conventional one with an external humidifier. Based on a modified PEMFC system model with ERG description added, the water content characteristics are captured in the presence and absence of EGR, and a comprehensive EGR strategy is developed. Analysis and simulation provide insights on how to effectively implement the EGR system. The simulation results demonstrated that these adverse water content conditions in PEM fuel cells can be well handled by adopting the proposed water management strategy.