Abstract:

In the mine gas explosion, preventing the explosion by extinguishant will help to fundamentally eliminate the disastrous consequence of gas explosion. In this paper, we set up double nozzles on the explosion pipeline, and explore the discharge of N₂ to achieve the explosion and extinguish the flame. For the straight pipe with surrounding sides inclosed, experiments are conducted with serial N₂ pressures, but none of them can prevent the explosion from spreading along the pipe. Then, in this paper, an opening on lower surface of the pipe is set for venting. It can be observed in the explosion process that a large number of high-temperature air masses and premixed gas flow out from the opening, and continuously react outside the opening. Combined with lateral venting, when the left nozzle in the double nozzle does not spurt nitrogen, the explosions still can't be prevented no matter the right nozzle spurting N₂ with various pressures. However, when the pressure of the left nozzle is 0.1 MPa and above, the explosions can be prevented. And the larger the N₂ pressure, the more easily preventing the explosion and quenching the flame is. The first major reason for preventing explosion is to weaken the reaction in pipe by lateral venting. Also, lateral venting in the pipe to reduce the explosion speed of propagation, more nitrogen is ejected out and longer period of time is obtained to fully dilute the premixed gas. That is the second main reason for preventing the explosion and quenching the flame.

Key words: methane, explosion, reaction, preventing the explosion, quenching the flame, venting, nitrogen

摘要：

矿井瓦斯爆炸发生后，采用灭火剂进行阻爆，将有助于从根本上消除爆炸的灾难性后果。本文在爆炸管道上设置双喷头，探索喷出N₂来实现阻爆和熄灭火焰。对于四周保持密闭的平直管道，采用不同压力将氮气喷出，但均未能阻止爆炸火焰沿管道的传播。在管道下表面设置开口进行泄压后，可以观测到爆炸过程中大量的高温气团和预混气从该开口流出，并在开口外继续发生反应。结合侧向泄压，当双喷头中左喷头（第二喷头）不喷N₂时，右喷头（第一喷头）所喷N₂在各个压力下也仍未能实现阻爆。但当左喷头（第二个喷头）压力在0.1 MPa及以上时，均能实现阻爆。并且双喷头所喷N₂压力越大，爆炸火焰被阻止和熄灭的位置越靠前。通过侧向泄压使管道内的反应变弱是有利于阻爆的第一个主要原因。侧向泄压使管道内爆炸火焰的传播速度下降，从而喷出更多氮气并获得更长的时间来对预混气进行充分稀释，这是实现阻爆和熄灭火焰的第二个主要原因。

关键词: 甲烷, 爆炸, 反应, 阻爆, 熄灭火焰, 泄压, 氮气