A Numerical Study of the Leakage and Diffusion Behavior of Hydrogen Dispensers in Hydrogen Refueling Stations Under Different Leakage Conditions

The investigation of hydrogen leakage and diffusion behavior is of great importance for the assessment of safety risks and the establishment of safety regulations for hydrogen refueling stations. However, the uncertainty associated with the location of hydrogen leaks and the complex environment pose challenges in understanding the diffusion characteristics of hydrogen leaks. In this research, a numerical analysis is performed to study the diffusion of hydrogen leaks in both horizontal and vertical directions under three different environments, considering two different sizes of leak holes. The results show that horizontal and vertical hydrogen leaks have different effects on the hydrogen diffusion behavior. The presence of a canopy and obstacles inhibits hydrogen diffusion and dilution, which could be the cause of more severe accidents. Moreover, the size of the leak hole also impacts the scale of the flammable gas cloud. The effect of leaking direction to the canopy is also considered. In comparison with the semi-open space, the pressure on the canopy is higher in an enclosed space.