Numerical simulation of process analysis and sensitivity analysis of factors influencing liquid hydrogen release in open spaces

Hydrogen is considered an ideal clean energy and is expected to gradually replace fossil fuels. Among the methods of hydrogen storage and transportation, liquid hydrogen storage offers the advantages of high energy density, safety at low temperatures, and the absence of high-pressure equipment, making it the most suitable method in many scenarios. However, in the event of an accidental liquid hydrogen leak, it will rapidly evaporate in large quantities, potentially causing significant hazards. A research project based on the open-source computational fluid dynamics (CFD) code, OpenFOAM, has been initiated for this purpose. The validity of the numerical model was confirmed by comparing it with NASA's large-scale liquid hydrogen release experiments conducted in open spaces, specifically through comparisons of hydrogen concentration contours and data collected by sensors. The deviations between the simulation results and the experimental data were within an acceptable range. The effects of atmospheric wind speed, ground type, atmospheric pressure, temperature, and release duration on the liquid hydrogen release process were analyzed. The changes in hydrogen concentration, the maximum movement distance of the hydrogen cloud, and the volume of the hydrogen cloud over time were analyzed and compared under different conditions. Finally, the impact of these factors on liquid hydrogen release within their possible natural ranges was compared. It was found that under natural conditions, atmospheric wind speed and release duration significantly affect liquid hydrogen release more than other factors. When atmospheric wind speed is high, more attention should be paid to preventing leaks, as the potential hazard downwind is enormous. In the event of a leak, it should be stopped as soon as possible to minimize the release duration.