Abstract: Hydrogen leakage in high pressure storage is easy to lead to spontaneous combustion. In order to explore the factors affecting the spontaneous combustion of hydrogen, the spontaneous combustion process of pressurized hydrogen in different pipe wall temperature and pipe diameter was simulated by using Realizable model, EDC model and 21-step hydrogen/air chemical reaction mechanism. The results show that the decrease of pipe wall temperature can significantly reduce the possibility of hydrogen spontaneous combustion. When the conveying pressure is less than 8 MPa, the increase of pipe inner diameter is not conducive to hydrogen ignition and spontaneous ignition. When the conveying pressure is too large (10 MPa), the increase of pipe inner diameter provides more space for expansion and diffusion of hydrogen jet, which is conducive to the formation of hydrogen/air mixture and promotes hydrogen spontaneous ignition.

Key words: high-pressure hydrogen leakage, pipe wall temperature, pipe diameter, spontaneous combustion, numerical simulation