采空区注氮对瓦斯爆炸危险区的影响数值模拟

为研究注氮对高瓦斯矿井采空区内瓦斯爆炸危险区的影响,以安徽许疃煤矿3235工作面为实例,使用COMSOL多物理场耦合模拟软件建立采空区注氮模型,分析了不同注氮流量及注氮位置条件下采空区气体运移规律,并依据线性叠加的数学原理对采空区瓦斯爆炸危险区进行划分,分析其分布特征。通过对比研究发现:随采空区注氮流量的增加,爆炸所需最低浓度的氧气和爆炸极限内的甲烷,分别有向工作面和采空区移动的趋势,瓦斯爆炸危险区的最大宽度以及面积均呈现减小趋势;注氮位置和瓦斯爆炸所需氧气体积分数的危险区域,在一定范围内呈现负相关性。

Numerical simulation of effect of nitrogen injection on gas explosion hazard in goaf

In order to study the effect of nitrogen injection on the gas explosion danger zone in the goaf of high-gas mines, taking the 3235 working face of a coal mine in Anhui Province as an example, the COMSOL multiphysics coupling simulation software was used to establish a model of nitrogen injection in the goaf, and the gas migration laws of goaf under different nitrogen injection flow rates and nitrogen injection positions were analyzed. According to the mathematical principle of linear superposition,the gas explosion hazard area of goaf is divided and its distribution characteristics are analyzed. Through comparative study, it is found that with the increase of nitrogen injection flow in the goaf, the oxygen with the lowest concentration required for the explosion and the methane within the explosion limit have the tendency to move towards the working face and the goaf respectively, and the maximum width and area of the gas explosion hazard area show a trend of decrease. The nitrogen injection position and the hazard area of the volume fraction of oxygen required for a gas explosion showed a negative correlation.