Visualization study on the effect of pulsating flow on the two-phase dynamic behavior of proton exchange membrane fuel cells in dead-ended anode mode

Water management is crucial for efficient operation of proton exchange membrane fuel cells in dead-ended anode mode. In this paper, a two-way hydrogen supply mode based on pulsating flow was proposed to mitigate water flooding. The causes of water flooding and the impact mechanism of pulsating flow on the two-phase dynamic behavior of proton exchange membrane fuel cells were experimentally explored. The research results showed that water vapor condensation and liquid water emerging from under the ribs were important factors leading to anode flooding. The proposed mode effectively alleviated flooding-induced performance degradation, improving the output performance and operational stability of proton exchange membrane fuel cells. Compared with conventional dead-ended anode mode, it increased output voltage by 2.8–4.3 % and reduced undershoot amplitude by nearly 50 %. Moreover, it enhanced thermal uniformity by reducing local water accumulation. Microscopic observations further demonstrated that pulsating flow generated alternating impact forces on the water and gas in anode channels, accelerating droplet removal and reducing the risk of flow channel blockage. provide These findings provide valuable insights into optimizing fuel cell water management, which is of great significance for improving the performance, stability, and durability of proton exchange membrane fuel cells.