CFD Analysis of Hydrogen Leakage from a Small Hole in a Sloping Roof Hydrogen Refueling Station

As a key link in the application of hydrogen energy, hydrogen refueling stations are significant for their safe operation. This paper established a three-dimensional 1:1 model for a seaport hydrogen refueling station in Ningbo City. In this work, the CFD software FLUENT was used to study the influence of leakage angles on the leakage of high-pressure hydrogen through a small hole. Considering the calculation accuracy and efficiency, this paper adopted the pseudo-diameter model. When the obstacle was far from the leakage hole, it had almost no obstructive effect on the jet's main body. Still, it affected the hydrogen, whose momentum in the outer layer of the jet has been significantly decayed. In this condition, there would be more hydrogen in stagnation. Thus the volume of the flammable hydrogen cloud was hardly affected, while there was a significant increase in the volume of the hazardous hydrogen cloud. When the obstacle was close to the leakage hole, it directly affected the jet's main body. Therefore the volume of the flammable hydrogen cloud increased. However, the air impeded the hydrogen jet relatively less because the hydrogen jet contacted the obstacle more quickly. The hydrogen jet blocked by the obstacle still has some momentum. Therefore, there was no more hydrogen in stagnation and no significant increase in the volume of the hazardous hydrogen cloud.