岩石撞击引发矿井瓦斯爆炸可能性的实验探索

Experimental exploration to gas explosion induced by rock impact

针对煤矿瓦斯灾害诱发背景及原因,结合前期固体撞击实验成果,利用热红外成像技术进行了沉积岩类岩石的撞击实验,发现撞击瞬间,岩石撞击中心部位或飞溅破碎体温度达到最大值,撞击升温可达218℃,且温度保持在100℃以上的时间超过1min;干燥岩石升温高于潮湿岩石,不规则岩石升温高于规则岩石,石灰岩升温高于砂岩.实验结果表明,岩石的撞击升温可能形成火源而引发瓦斯爆炸.在此基础上,针对岩石撞击升温的三大机理,即岩石破裂摩擦、岩石热弹效应及岩石物理机理,讨论并提出了防止因岩石撞击升温形成火源并引爆矿井瓦斯的某些措施与途径.

In consideration of the background of gas explosion in coal mine, a group of experiments on rock impact was conducted by means of thermal infrared (TIR) imaging technique based on the results of former experiments on solid impact. It was discovered that it generally gets to the maximum temperature at the transient of impact, either at the center of the impact area or at the splashing chippings of the rock(the maximum temperature can be up to 218 ℃), and it can be above 100 ℃ for one minute, and as to the amplitude of the temperature increment, it is larger for dry rocks than wet ones, for irregular rocks than regular ones, and for limestone than sandstone. It shows that the increment of temperature due to rock impact could probably ignite the gas in coal mine. Three possible mechanisms were presented for the variation of impact temperature, i.e., rock fracture and friction, thermo-elastic effect and physics of rock. Hence, some technical measures and approaches for preventing gas explosion resulting from rock impact were presented.