突出煤层区域性瓦斯抽采数值模拟研究
Study on Numerical Simulation of Regional Gas Drainage in Outburst Seam
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摘要: 根据流体力学和岩体力学理论,以神宁集团金能煤业分公司4331工作面为研究对象,建立了突出煤层区域性瓦斯抽采数值模型,并采用COMSOL Multiphysics软件进行数值计算,讨论了该区域煤层瓦斯压力和煤层孔隙率随瓦斯抽采时间的变化规律。结果表明:区域性瓦斯抽采钻孔的群孔效应明显,模拟抽采100 d后绝大部分区域瓦斯压力降到突出临界值0.74 MPa以下;煤层孔隙率快速上升,先达到峰值,然后回落到恒定值,比初始孔隙率增加了4.8%,其结果对4331工作面区域瓦斯防治及制定区域防突措施有重要的理论意义。Abstract: Taking No.4331 coal mining face in Jinneng Coal Company of Shenning Group as a study object, according to the fluid mechanics and the rock mechani CS theory, a numerical model of the regional gas drainage in the outburst seam was established.The COMSOL Multiphysics software was applied to the numerical calcul ation.The paper discussed the variation law of the gas pressure in the regional seam and the seam crack rate with the gas drainage time.The results showed that the gr oup borehole effect of the regional gas drainage was obvious . After 100 days of the simulated gas drainage, the regional gas pressure in major area was reduced below the critical value of 0.74 MPa.The permeability of the seam would rapidly increase and when the permeability reached to the peak value, the permeability would return t 0 the constant value, which was 4.8% higher than initial porosity.The results would have important theoretical significances to the regional gas prevention and control of No.4331 coal mining face and to the regional outburst prevention measures set up.