Simulation study of energy efficiency of proton exchange membrane electrolyzer based on fluid phase field under microgravity

Proton exchange membrane water electrolyzer (PEMWE) is a promising clean renewable energy hydrogen production technology device, and it is also one of the key technologies of the space station's environmental control and life protection system. In microgravity, bubble management within PEMWE is extremely important for the energy conversion efficiency of the system. In this study, a multiphysics model based on electrochemical model coupled with fluid phase field was developed to study the influence of basic parameters on bubble migration behavior and electrochemical efficiency in PEMWE under gravity microgravity environment. The results show that in the microgravity environment, high inlet water flow velocity should be avoided, so as to reduce the bubble coverage of the bottom wall. To avoid forming a thin film flow blocking the lower wall of the runner, it is recommended that the anode runner maintain a depth of 1 mm while avoiding high outlet pressure. In the gravity environment, the inlet water velocity has a relatively low effect on the bubble coverage of the lower wall. However, high outlet pressures should be avoided to prevent electrochemical efficiency degradation due to high bubble coverage. In the anode runner, the flow channel depth of 0.8mm is easy to form a thin film flow, and blocking the flow channel affects the electrochemical efficiency. These findings provide a valuable research basis for PEMWE's bubble management and electrochemical efficiency improvement.