Ultimate pressure-bearing capacity of Type III onboard high-pressure hydrogen storage tanks under typical accident scenarios

Sufficient pressure-bearing performance was the basis for ensuring the safety of hydrogen storage tanks in service for the entire life cycle. The aim of this study was to analyze the ultimate pressure-bearing capacity of tanks under possible working conditions, such as room temperature, fire, and after flame exposure. The results show that the actual burst pressure of a Type III tank of 48 L and 70 MPa at room temperature was 209.80 MPa, which had sufficient explosion-proof behavior. Compared with the room temperature, the critical failure pressure of the tank under fire conditions dropped sharply by ca. 63.1 %, which readily induced pressure-bearing failure. However, after cooling to room temperature, the residual burst pressure of the tank thermally damaged by fire was only roughly 14.5 % lower than the ultimate pressure-bearing pressure at room temperature, and still maintained a certain strength. The grey correlation analysis model of influencing factors on the ultimate pressure-bearing performance of tanks in normal temperature and fire environments was established for the first time. This paper reports quantitatively that, in addition to the nominal working pressure, the design wall thickness of the tank at room temperature has the most prominent effect on the pressure-bearing performance. While the initial filling pressure and flame exposure time in fire environments were considered to be the key factors affecting the pressure bearing performance.