Study on hydrogen diffusion and combustion characteristics of hydrogen fuel cell sightseeing vehicles in open space

Hydrogen fuel cell sightseeing vehicles (HFCSVs) are usually driven in densely populated areas; the release of hydrogen may pose a threat to the safety of people. In this study, we explore the effects of the locations and heights of hydrogen storage tanks and the modes of parking on hydrogen diffusion and combustion in open space by activating the thermally activated pressure relief device (TPRD) of the hydrogen storage tanks. The results show that the diffusion distance of combustible hydrogen clouds is the largest when the hydrogen storage tank is in front; when the hydrogen storage tank is in the middle, the diffusion distance of combustible hydrogen clouds is the smallest, the time to reach the maximum is the shortest, and the minimum safety range is the smallest. The lower the height of the hydrogen storage tanks, the smaller the maximum volume of combustible hydrogen cloud and the larger the flame spreading range. When parking at 60°, 45°, and 30°, the maximum length of the combustible hydrogen cloud is almost the same. Under 30° parking, the right vehicle always has no flame distribution and will not activate TPRD due to a jet flame; this parking is the safest. • Established a CFD model for an open space hydrogen fuel cell sightseeing vehicle. • Explored the impact of hydrogen tank layout and parking modes on diffusion and combustion. • The diffusion distance of hydrogen is minimum when the hydrogen tank is in the middle. • The lower the height of the hydrogen storage tank, the larger the flame spreading range. • Compared to other parking modes, 30° parking is the safest.