受限空间掺氢天然气燃爆特性的实验研究

Experimental Study on the Explosion Characteristics of Hydrogen-blended Natural Gas in Confined Spaces

为了评估受限空间内掺氢天然气燃爆事故后果,开展了受限空间掺氢天然气燃爆特性研究,并通过设计长径比为43.8的矩形测试管道及测试系统,研究了掺氢比、燃烧当量比对掺氢天然气燃爆特性的影响。结果表明:随着掺氢比增加,火焰燃烧剧烈程度增加,火焰传播速度增大,尤其当掺氢比高于20%,管道内呈现剧烈的大尺度湍流火焰;掺氢比增加,管内超压增大,当掺入30%氢气时,最大爆炸超压增大48.6%,掺入50%氢气时,最大爆炸超压增大76.7%;不同掺氢比下,管内火焰速度沿传播方向呈现震荡升高的趋势;相比不掺入氢气,掺入20%、30%、50%氢气后,火焰传播平均速度分别增加67.83%、92.38%、165.81%。研究结果可为掺氢天然气事故定量评价以及管廊等受限空间的安全设计提供参考。

A study was conducted to assess the consequences of hydrogen-blended natural gas(HBNG)explosions in confined spaces.By designing a rectangular test pipeline and testing system with a length-to-diameter ratio of 43.8,the effects of hydrogen concentration and equivalence ratio on the explosion characteristics of HBNG were investigated.The results reveal that as the hydrogen concentration increases,the intensity of flame combustion and the propagation velocity of the flame also increases.Particularly,when the hydrogen concentration exceeds 20%,the pipeline exhibits intense large-scale turbulent flames.With an increase in hydrogen concentration,the overpressure inside the pipeline also increases.When 30%hydrogen is introduced,the maximum explosion overpressure increases by 48.6%,and when 50%hydrogen is introduced,the maximum explosion overpressure increases by 76.7%.Under different hydrogen concentrations,the flame velocity inside the pipeline shows an oscillating upward trend along the direction of propagation.Compared to no hydrogen addition,the average flame propagation velocity increases by 67.83%,92.38%,and 165.81%with the addition of 20%,30%,and 50%hydrogen,respectively.The research findings can provide guidance for the quantitative assessment of HBNG accidents and the safety design of confined spaces such as utility tunnels.