关键词: 氢, 安全, 爆炸, 膜片压力, 火焰传播, 超压

Abstract:

Due to the characteristics of low ignition energy and wide combustion range, hydrogen is prone to explosion accidents after leakage. To effectively control explosion pressure, venting measures are widely utilized, with vent membrane thickness identified as a critical factor influencing venting performance. Based on the fact that the boundary effect of short pipes is more obvious, a square pipe with a length-to-diameter ratio of 10∶1 was selected to carry out explosion experiments with a diaphragm pressure (P_v) range of 0—48 kPa. The results indicate that an increase in membrane pressure significantly prolongs the flame propagation time, with the flame propagation velocity exhibiting a trend of initial decrease followed by an increase. The maximum overpressure difference between the two ends of the pipe decreases with increasing membrane pressure. Compared to 15 kPa, the pressure differences at 28, 39, and 48 kPa decrease from 30.08 kPa to 28.96, 20.68, and 10.44 kPa, respectively. The pressure-time curve at the venting end displays a double-peak structure, with the second peak pressure (P_ext) being lower than the initial peak pressure. During the early stages, flame and pressure propagation are hindered by the tensile strength of the membrane. After the membrane ruptures, the pressure rises sharply, and the flame exhibits oscillatory propagation within the pipe. Additionally, the pressure amplitude increases significantly with higher membrane pressure.

Key words: hydrogen, safety, explosion, vent burst pressure, flame propagation, overpressure