Objective  In case of hydrogen leakage, it can quickly diffuse and mix with the surrounding air, forming a combustible vapor cloud, which may cause combustion and explosion accidents. Numerical simulation of this process can effectively help engineers and workers reduce risks.

  Method  Using Fluent computational fluid dynamics software, simulation and analysis were conducted on various hydrogen-related facilities of the "Delingha PEM Water Electrolysis for Hydrogen Production Project", such as H₂ release ports, O₂ release ports, 20 MPa high-pressure tube bundles, and 2.8 MPa large-capacity storage tanks, to evaluate the consequences of continuous leakage incidents under environmental wind speed and temperature conditions.

  Result  The results indicate that: 1) the H₂, O₂ release ports do not pose a risk of hydrogen explosion or create an oxygen-rich environment outside the hydrogen production plant. The main potential hazards are ignition sources such as naked fire and sparks that could trigger fires. It is recommended to install static elimination devices, and, whenever possible, recycle oxygen; 2) Regarding the high-pressure tube bundles and storage tanks, the differences are that the hydrogen leakage rate of high-pressure tube bundles are fast, and the leakage time of the storage tanks is long. It is recommended to install thermal imaging hydrogen detection and alarm devices in conjunction with the construction of protective walls, limit access for personnel, and prohibit operators from carrying ignition sources and non-explosion-proof apparatus into hazardous areas.

  Conclusion  The patterns of hydrogen leakage and diffusion across different scenarios offer strong theoretical support the design of the hydrogen leakage safety warning system during the project implementation phase and for risk reduction.