煤矿采空区顶板岩石摩擦对瓦斯的点火特性

Ignition Characteristics of Sliding Friction between Rock Blocks of Gob Roof

在描述煤矿采空区顶板铰接岩块滑落失稳摩擦过程的基础上,基于热传导理论和对流换热相似原理,给出岩石摩擦表面的最大闪温计算公式和热条痕及炽热颗粒点燃瓦斯的临界特征尺寸,得出:最大闪温与相对摩擦速度的平方根和顶板周期来压步距的平方成正比,岩石摩擦产生的热条痕对瓦斯的点燃能力要大于炽热颗粒。当采空区顶板岩层比较坚硬时,在其周期来压时极易引发瓦斯燃烧或爆炸事故。

On the basis of describing the friction process of articulated rock in the process of sliding instability, based on the theory of heat conduction and similar principle of convection heat transfer,derived the formula of maximum flash temperature on the surface of the rock friction and the critical feature size of methane ignition by hot streaks and hot particles. And some conclusions were achieved that the maximum flash temperature is proportional to the square root of relative friction velocity, the ability to ignite methane by hot streaks is greater than by hot particles. In addition, rock friction can easily lead to a gas fire or gas explosion during periodic weighting in case that the gob roof strata are relatively hard.