CFD Study on High-Pressure Hydrogen Leakage and Explosion of Hydrogen Energy Tram in Tunnel

Abstract

Abstract As hydrogen energy is gradually being applied to vehicles, confirming the safety level is becoming important. Meanwhile, tunnels are common in cities. Compared with hydrogen fuel cell cars (HFCVs), hydrogen fuel cell trams have a larger size and the corresponding space of the tram tunnel is also narrower. However, most hydrogen fires in confined spaces are HFCVs. The consequences of hydrogen leakage and explosion in a tunnel of the hydrogen energy tram are different. Therefore, computational fluid dynamics (CFD) method was used to study the hydrogen diffusion and explosion caused by the accidental opening of the thermal pressure relief device (TPRD) of the high-pressure hydrogen storage cylinders on the hydrogen energy tram in the tunnel. The effect of the number of TPRDs opening and the speed of wind on the formation of flammable hydrogen clouds is discussed. The simulation results show that the burning area generated by igniting the hydrogen cloud can cover more than one hundred meters, and overpressure can cause serious injuries to the human body. High temperature and overpressure can be relieved by the wind. In case of accidental hydrogen leakage, the tram should be blocked until the tram continues to move to a safe area and there should be forced ventilation in the tunnel. This research highlights the importance of ensuring the safety of hydrogen fuel cell trams in confined spaces such as tunnels.