煤矿瓦斯爆炸阻隔爆技术现状及展望

煤矿主要采用隔爆水棚或岩粉棚来抑制瓦斯爆炸火焰传播,但此类技术仅针对一次性瓦斯爆炸,而缺乏对多次及连续瓦斯爆炸的有效阻隔爆手段。仅注重对燃烧波的淬熄作用,对造成很大破坏的冲击波的衰减效果不足。多孔介质的淬熄火焰和衰减冲击波的效能已得到国内外专家的重视,实验研究了多层丝网和多孔材料如泡沫铝和泡沫陶瓷的阻隔爆效果。泡沫陶瓷作为一种多孔介质,具有开孔率大、耐高温、抗冲击力强的优点。理论分析和实验研究表明,由于壁面的多次撞击效应,多孔介质可以有效地销毁瓦斯燃烧化学反应产生的自由基数量,抑制化学反应的放热,使化学反应不能自持进行,进而淬熄燃烧火焰传播;可以大幅衰减瓦斯爆炸的冲击波强度,起到同时淬熄燃烧火焰和衰减冲击波的作用。多孔介质有望成为煤矿井下一种新型的瓦斯爆炸阻隔爆材料和方法。

Status quo and prospect of gas explosion suppressing and isolating techniques in coal mines

At present,coal mines largely resort to water tubs or rock barriers to suppress gas explosion flame propagation,but they concentrate only on initial gas explosions,and are inadequate to suppress and isolate multiple and continuous gas explosions.Moreoever,these devices mostly focus on quenching of combustion waves,and cannot significantly attenuate shock waves responsible for enormous damage.Thanks to its excellent performance in flame propagation quenching and shock wave attenuation,porous medium has attracted the attention of specialists worldwide.They investigated the gas explosion suppression effects of multilayer mesh and porous material.Foam ceramic is characterized with large porosity and resistance against high temperature and shock force.Theoretical analysis and experimental study suggested that,due to numerous collisions with the skeletons in porous medium,the free radicals generated in the chemical reactions of gas combustion can be largely destroyed,the heat release can be restrained,thus making the chemical reactions non-self-sustained.As a result,flame propagation is quenched.Furthermore,porous medium can markedly attenuate the shock waves,decoupling the combustion waves and shock waves.The materials are expected to become a new-generation gas explosion suppression and isolation technique in coal mines.