双巷掘进工作面中间煤柱瓦斯流动理论分析

Theoretical Analysis on Gas Flow of Middle Coal Pillars Between Two Seam Gateway Heading Faces

为了加强双巷掘进工作面的通风管理,分析了双巷掘进工作面中间煤柱瓦斯流动特点并建立了有限流场瓦斯流动的理论方程,根据边界条件和初始条件并运用数学物理方法求出理论方程的解析解,得出了描述中间煤柱瓦斯压力分布的计算公式,推导出计算中间煤柱煤壁单位面积瓦斯涌出量的公式,并利用端氏煤矿实测数据对公式进行了计算。结果表明:煤壁瓦斯涌出量的大小取决于煤层原始瓦斯压力、煤层透气性系数、煤层瓦斯含量系数和煤壁暴露时间;采用瓦斯涌出量计算公式算出的中间煤柱煤壁瓦斯涌出量符合现场的瓦斯涌出特征,其计算值与现场实测值的相对误差小于10%。

In order to enhance the ventilation management of the two seam gateway heading faces,the paper analyzed the gas flow features of the coal pillars between the two seam gateway heading faces and the theoretical equation of the gas flow in the limited flow field was established.According to the boundary conditions and the initial conditions,the mathematic physical method was applied to obtain the analytic explanation of the theoretical equation,obtained the calculation formula to describe the gas pressure distribution of the middle coal pillar and to derived the formula to calculate the gas emission value of the coal wall unit area of the middle coal pillar.The site measured data in the Duanshi Mine was applied to calculate the formula.The results showed that the high or low gas emission value from the coal wall would be dependent on the seam original gas pressure,seam gas permeability coefficient,seam gas content coefficient and coal exposed time.The gas emission value from the middle coal pillar wall calculated with the gas emission calculation formula could meet the site gas emission features and the relative error between the calculated value and the site measured value was less than 10%.