INVESTIGATION ON ON-BOARD HIGH-PRESSURE COMPOSITE TANKS SUBJECTED TO LOCALIZED AND ENGULFING FIRE

Safety performance of on-board high-pressure composite tanks under fire exposure has drawn extensive attention. Vehicle fires usually lead to such tanks experiencing a term of localized and engulfing fire. During this period, the composite tank would be degraded and even burst before pressure relief device (PRD) opens to release internal high-pressure gas. In this paper, experimental investigation for the tanks subjected to localized and engulfing fire was conducted on an Aluminum liner composite tank filled with hydrogen. Based on the temperature distribution and pressure rise measured in the experiment, a three-dimensional computational fluid dynamics model is developed to study the key factors influencing PRD activation time. The effects of filling medium, tank pressure and localized fire exposure time are analyzed in detail. The experimental results showed that pressure and temperature of internal gas changed little during the localized fire. In addition, filling medium and tank pressure have weak influence on the activation time of thermally-activated PRD (TPRD), but have significant effect on the activation time of pressure-activated PRD. TPRD can respond more quickly to protect the hydrogen composite tank than pressure-activated PRD. PRD activation time increases as the localized fire exposure time extends.