独头巷道内瓦斯运移规律数值模拟

Numerical simulation of gas migration law in blind roadway

独头巷道内瓦斯异常涌出是引起煤矿井下瓦斯爆炸事故的主要原因之一。采用计算流体力学软件对独头端异常涌出后瓦斯在巷道中时空分布规律进行数值模拟研究。独头端的涌出速度采用幂函数的变化规律进行模拟。模拟过程监测了不同时刻巷道中心线瓦斯浓度分布情况以及巷道不同断面瓦斯浓度分布等值线图。模拟结果表明,巷道上部分瓦斯浓度比下部分瓦斯浓度大,瓦斯浓度沿巷道分为3个部分:先降低,后升高,然后又降低。涌出后一段时间瓦斯浓度降低部分非常短,整个瓦斯浓度是升高部分,且沿巷道长度方向基本呈直线升高。该研究对矿井瓦斯爆炸事故调查、通风风量调节、灾害预警以及应急救援具有一定的意义。

Gas abnormal emission in blind roadway is one of main reason of gas explosion in coal mine. Gas distribution changes with time and place is simulated using CFD software, and the power exponent is used to simulate outburst velocity, and air quantity is the same as normal air quantity. Gas concentration variation along middle roadway of different point and gas concentration contour of different time are monitored during simulation. The result shows that, in blind roadway with ventilation, gas concentration in the upper roadway is higher than that of lower tunnel during gas abnormal emission. The gas concentration reduces first, then rises, and then reduces again. A few minute after emission, the distance of reduce is very short. Gas concentration increased dramatically along the roadway. The study is significant to investigate the cause of the gas accident, personal protection, disaster warning and emergency response guidance.