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

摘要：

氢气因低点火能、宽燃烧范围的特点，泄漏后极易发生燃爆事故。为有效控制爆炸压力，泄压措施被广泛采用，其中膜片压力被认为是影响泄压效果的关键因素。基于短管道边界效应更加明显，选取长径比为10∶1的方管，开展膜片压力（P_v）范围为0 ~ 48 kPa的爆炸实验。结果表明，膜片压力的增加显著延长火焰传播时间，火焰传播速度呈先下降后升高的趋势；管道两端最大超压差值随P_v的增加而减小，与P_v = 15 kPa相比，28、39、48 kPa时管道两端压差从30.08 kPa减小至28.96、20.68和10.44 kPa；泄爆端压力-时间曲线呈双峰结构，第二峰值P_ext低于初始峰值；火焰与压力的传播在初期会受到膜抗拉强度的阻滞，膜破后压力急剧攀升，火焰呈往返振荡现象，压力振幅随膜片压力的增加而显著提升。

关键词: 氢, 安全, 爆炸, 膜片压力, 火焰传播, 超压