Insights into the uniformity of gas distribution in proton exchange membrane fuel cell under low-pressure scenarios

Due to safety concerns, residential proton exchange membrane fuel cells (PEMFCs) operate at significantly lower pressures, which heightens the risk of water condensation and anode flooding due to reverse osmosis. Consequently, investigating the flow field distribution under low-pressure scenarios is crucial. However, research on low-pressure PEMFCs remains limited. This study introduces an innovative visualization technique combined with numerical simulation to investigate the influence of different flow field inlet configurations, inlet pressures, and flow rates on gas distribution uniformity under low-pressure conditions. A novel visualization experimental device is developed to verify gas flow behavior under different operating conditions. The device uses polystyrene (PS) microspheres as tracer particles, combining the “velocity determination by image difference (VDID)” method—a cost-effective and efficient alternative to particle image velocimetry (PIV). Four flow field designs—ipsilateral access flow field (IAFF), opposite access flow field (OAFF), middle access flow field (MAFF), and entire access flow field (EAFF)—are modeled and experimentally validated. The results indicate that the EAFF consistently outperforms other designs, achieving a low coefficient of variation (CV) of 0.62% across various operating conditions. These findings highlight the effectiveness and convenience of visualization experiments combining microsphere tracer with the VDID method for early-stage flow field design and underscore the superiority of EAFF for low-pressure PEMFC applications.