坚硬顶板垮落诱发瓦斯爆燃机理及预防

Methane burning and explosion mechanism induced by hard roof collapse and its prevention

以夏阔坦综放工作面为研究对象,通过试验研究和理论分析,研究了坚硬顶板垮落撞击摩擦发火现象及诱发采空区瓦斯爆燃机理,运用流体动力学分析软件Fluent模拟分析采空区瓦斯分布规律及易爆燃部位。研究结果表明:坚硬石英砂岩顶板在垮落撞击摩擦过程中产生高温火花,能够引燃采空区瓦斯,诱发瓦斯爆燃事故;撞击摩擦面升高的温度ΔT与垮落岩体质量m、垮落高度H成正相关关系,接触面的升温随着垮落岩块体积及其冒落运动高度的增加而增大。根据采空区瓦斯浓度分布规律,工作面"U"型通风方式下瓦斯易燃易爆点分布在上端头采空区靠近工作面部位;"Y"型通风方式下瓦斯易燃易爆点主要分布在工作面中部采空区,并提出了强制放顶、采空区矸石喷水、注入惰性气体和采空区瓦斯抽放等预防措施。

Taking a fully mechanized top-coal caving face in Xiakuotan Mine as research object, the impact and friction ignition phenomenon caused by hard roof collapse and the mechanism of inducing methane burning and explosion in goaf was studied and by experimental study and theoretical analysis, and the methane distribution law and easy-burning and explosion location in goaf were simulated by using Fluent Software. The results show that the collapse impact and fiction process of hard quartz sandstone roof may produce high temperature spark, which may ignite methane within goaf and induce methane burning and explosion accident. The increased temperature of impact friction surface ΔT is positively correlated, with the mass of collapsed rock m and collapse height H, that is, ？T value in impact friction surface will increase as m and H increase. Based on distribution law of goaf methane concentration, the easy-burning and explosion area locates at upper goaf near caving face in the U-type ventilation mode, while the area may mainly distribute in middle goaf in the Y-type ventilation mode. Prevention techniques such as forced roof caving, water and inert gas injection of goaf gangue, and goaf gas drainage, etc, has been put forward.