论文部分内容阅读
在研究煤层瓦斯抽采时,假定煤岩为具有孔隙裂隙的双重介质,在运动方程、连续性方程和辅助方程基础上,以煤岩体应变为耦合媒介建立了考虑裂隙瓦斯渗流、微孔隙吸附瓦斯解吸扩散和煤岩变形的渗流模型。借助多物理场分析软件COMSOL Multiphysics,将模型转化为偏微分方程组,结合沙曲矿24305工作面瓦斯赋存条件进行分析求解。结果表明,进行煤层瓦斯预抽时,抽采初期瓦斯压力下降较快,抽采孔间距对抽采效果影响比较显著,距离抽采孔越远瓦斯压力下降越慢,抽采时瓦斯渗流速度变化可分3个阶段。参考模拟结果现场布置孔距为6 m的顺层钻孔,抽采稳定时瓦斯纯量达5~7 m3/min,抽采效果比较理想。
In the study of gas drainage in coal seam, coal and rock are assumed to be dual media with pore fissures. Based on the equations of motion, continuity and auxiliary equations, Seepage model of gas desorption and diffusion and coal and rock deformation. With multi-physics analysis software COMSOL Multiphysics, the model is transformed into a set of partial differential equations, combined with gas storage conditions of 24305 working face of Shaqu Mine. The results show that when gas pre-pumping in coal seam, the gas pressure drops rapidly in the early stage of gas drainage, and the influence of drainage hole spacing on drainage effect is significant. The gas pressure drop is farther away from the drainage hole and the gas seepage velocity Can be divided into three stages. Based on the simulation results, a series of bore holes with a hole spacing of 6 m were arranged on the spot. The pure gas content of the gas reached 5 ~ 7 m3 / min during pumping and stable operation, and the pumping effect was quite satisfactory.