Numerical investigation of the dispersion features of hydrogen gas under various leakage source conditions in a mobile hydrogen refueling station

The leakage and dispersion of hydrogen gas in a mobile hydrogen refueling station is being numerically investigated in this paper. The investigated geometry is derived from the mobile hydrogen refueling station in China. The numerical models are verified by experimental data. The hydrogen gas leaks from the hydrogen buffer tank in the form of momentum-dominated jet. The combustible danger region, the hydrogen concentration distribution, and the volume of hydrogen gas cloud are investigated. The effects of leakage positions and leakage flow rates on the characteristics and evolution of hydrogen diffusion in the mobile hydrogen refueling station and the open space are analyzed. The results show that the hydrogen concentration in the 3-way corner of the ceiling opposite the leakage orifice first reaches 0.4% and 4%. When the leakage orifice faces the sidewall of the truck container, the liquid hydrogen storage is completely surrounded by hydrogen gas clouds in the flammability limit. The maximum diffusion height of hydrogen at the lower flammable limit increased as the leakage flow rate increased, and the volume of hydrogen in the flammability limit increased virtually exponentially in the open space. The research findings provide a significant reference for potential explosion and risk assessment studies of mobile hydrogen refueling station.