煤矿火区封闭过程中瓦斯积聚规律研究及危险性分析

Law of gas accumulation and analysis of danger of gas explosion during sealing fire zone in coal mine

为研究煤矿火区封闭过程时瓦斯的积聚规律,降低封闭区域内气体爆炸的危险性,实现矿井火区的安全封闭,通过对回采工作面瓦斯涌出量数学模型的分析,以封闭区域为研究对象,根据质量守恒定律建立瓦斯量平衡定律,推导密闭后封闭区域内瓦斯体积分数变化的数学模型,从理论上分析矿井发火区封闭后封闭区域内气体发生爆炸的原因及影响因素;以黑龙江鹤岗矿业集团兴安矿综采工作面封闭火区时瓦斯爆炸事故为例进行分析,从机理上提出封闭工作面时防止瓦斯爆炸的方法。研究结果表明:在火区封闭过程中风速下降,会引起瓦斯积聚的现象,从而改变封闭区域内的瓦斯分布状态,在高温火源存在的情况下易引发瓦斯爆炸事故;在进行火区封闭过程中,以适当速度注入一定量的惰性气体可以起到稀释以及降温的作用,是封闭灭火过程中的一种安全有效的技术措施。

In order to study the law of gas accumulation in the process of building airproof wall,to reduce the risk of gas explosion in enclosed fire zone,and to achieve security closure for the fire zone in coal mine,the equilibrium law of gas content for sealed fire zone was established according to the law of conservation of mass through analyzing the mathematical models of gas emission in working face.The mathematical model of gas concentration change in sealed fire area was deduced,and the reasons and influencing factors were analyzed theoretically after sealing the fire area in coal mine.Through analyzing the gas explosion accident in the fully-mechanized face during fire zone sealing period in Xing'an Coal Mine of Hegang Mining Group of Heilongjiang,the methods preventing gas explosion and its mechanism were put forward during fire zone sealing working face.The results show that the decrease of wind speed in the fire area during sealing can cause gas accumulation,therefore,the distribution of gas in the enclosed area can be changed,and gas explosion can occur easily if the higher temperature exists.During the course of sealing the fire zone,a certain amount of inert gas injected by an appropriate speed can play a role of dilution and cooling.Injecting inert gas is a safe and effective technical measurement during sealing the fire area.