Quenching characteristics and mechanism of hydrogen-air mixtures by corrugated plate flame arrester under inert conditions

Abstract

In this study, the flame quenching performance of flame arresters under the inerting conditions for existing pipeline of hydrogen refueling station is investigated. The critical concentration of inert gas and the critical flame quenching velocity of hydrogen explosion are obtained. The results show that hydrogen explosion overpressure decreases significantly with the increase in flame arrester thickness or decrease in porosity. Furthermore, the presence of flame arresters significantly reduces the inert gas concentration required to achieve the flame quenching effect. For the same flame quenching effect, the amount of CO2 used is less than that of N2. The laminar burning velocity of hydrogen at different inert gas concentrations is calculated and the sensitivity analysis is performed. It is found that the poor combustion state is more sensitive to N2 inerting. Considering the inerting effect of inert gas on hydrogen explosion, the flame quenching criterion is modified. The flame quenching temperature of hydrogen under different critical concentrations of inert gas and parameters of corrugated plate of flame arrester is calculated. It is found that the quenching temperature of hydrogen is approximately 1500 K. The moderation effect of inert gas and corrugated plate flame arresters on hydrogen explosion are mutually enhancing. In summary, smaller porosity leads to higher fluid–solid heat transfer efficiency; smaller critical concentration of inert gas, and higher quenching temperature.