Risk analysis of high-pressure hydrogen leakage in confined space with tube skid container for cylinder

The hydrogen tube skid container is designed to protect the hydrogen gas cylinder group from insolation, rain, and other environmental factors. However, in the event of a leakage accident, the container becomes a confined space. Therefore, it is essential to assess the risks associated with high-pressure hydrogen leakage in this confined space and determine the effectiveness of various risk mitigation methods under conditions of natural ventilation and forced ventilation, taking into consideration factors such as inlet velocity and vent position. The results showed forced ventilation was more effective than natural ventilation in reducing potential risks associated with hydrogen leakage. Furthermore, the magnitude of inlet velocity and the positioning of the vent were found to play crucial roles in reducing hydrogen concentration within the confined space. The vents on the horizontally symmetrical top (R-UP cases) were the most effective for ventilation. With the inlet air velocity set to 15 m/s, forced ventilation could reduce the average hydrogen molar fraction to the theoretical lower flammability limit (LFL) in approximately 17 s.