The Simulation and Analysis of Leakage, Diffusion Behavior, and Risk Mitigation Measures in a Hydrogen‐Refueling Station

As an component of hydrogen energy utilization, hydrogen‐refueling stations require considerable attention regarding their safety. In this study, the influence of wind conditions is analyzed, specifically no wind and 10 m s−1 wind speed, on hydrogen diffusion characteristics following a 70 MPa hydrogen‐filling machine leakage. In the results, it is suggested that, during the initial stage of leakage, hydrogen exists in the form of an under‐expanded jet, later transitioning to diffusion dominated by buoyancy and wind conditions after moving upward for a certain distance. When there is no wind, hydrogen is significantly affected by buoyancy and obstacles, which leads to the formation of flammable clouds. In windy conditions, the volume fraction of hydrogen in the station is smaller than that in the no‐wind condition at the same leakage time, but the flammable clouds still predominantly distribute in the direction of the hydrogen jet. In this study, risk mitigation measures based on the distribution of flammable clouds are proposed. In the results, it is shown that after implementing these measures, the volume of flammable clouds is reduced from0.135 to 0.014 m3, manifesting the effectiveness of risk mitigation measures and minimizing the risk of hydrogen explosion. In this study, FLUENT software is used to simulate the leakage of a 70 MPa filling machine in a hydrogen refueling station under different wind conditions: no wind and 10 m s−1 wind speed. The hydrogen diffusion characteristics are analysed, and explosion risk mitigation measures are proposed and validated according to the distribution of flammable clouds.