Abstract:

The diffusion behavior of dangerous hydrogen gas after a continuous liquid hydrogen leakage in a hydrogen refueling station is researched, which can provide the thearetical basis for safety protection design. It is assumed that a medium aperture leak occurred in a liquid hydrogen storage tank under 10 m/s westerly wind conditions, and the direction of the leak is the same as the wind direction. A 220 m length calculation domain and a hydrogen refueling station model in the downwind direction based on Fluent soft are established. A 100 s transient numerical simulation of liquid hydrogen leakage phase transition and diffusion is completed. The results indicated that the flammable hydrogen cloud reached its maximum diffusion distance of 83.77 m at 54 s and then stabilized, the vertical diffusion height of the hazardous hydrogen cloud does not exceed 10 m, and the explosive and low-temperature hydrogen clouds are confined within the U-shaped wall. Therefore, in the future the safety protection radius for flammable gases at liquid hydrogen refueling stations should not be less than 83.77 m. It is necessary to strictly reduce the layout of equipment around liquid hydrogen storage tanks and focus on the protection of the space below 10 m of the refueling station.

Key words: hydrogen, leakage, diffusion, numerical simulation, safety protection