高温场下矿井煤层钻孔瓦斯抽排效果研究

    Study on gas emission effect of coal seam borehole under high temperature field

    • 摘要: 针对我国煤矿低透气性突出煤层瓦斯抽放困难问题,以贵州省麦子沟煤矿K15煤层采煤工作面运输巷为工程背景,通过建立高温场下矿井采掘工作面排放钻孔瓦斯流动多场耦合模型,模拟研究了不同加热温度、钻孔孔径及不同钻孔间距下的煤层钻孔瓦斯排放效果。研究表明:温度对煤层瓦斯排放效果影响显著,当加热温度为86 ℃时,瓦斯压力降低明显;钻孔孔径对煤层瓦斯排放效果影响较大,当孔径为113 mm时,钻孔之间瓦斯压力最大为0.36 MPa,最大瓦斯压力同比下降了14.28%,钻孔瓦斯排放量提高了27.27%;钻孔间距对煤层瓦斯压力与排放效果影响也十分明显,当钻孔间距为1 m时,钻孔之间瓦斯压力最大为0.45 MPa,影响范围为5.72 m,相比钻孔间距为1.5 m时,瓦斯压力下降幅度增加了37.8%,相比钻孔间距为0.75 m时,影响范围增加了18.18%,综合瓦斯排放效果最好;对比不同方案的模拟结果,数值模拟方案9对应的瓦斯排放效果最佳。

       

      Abstract: Aiming at the difficult problem of gas drainage in low permeability outburst coal seam in China, taking the transportation lane of coal mining face in K15 coal seam of Maizigou Coal Mine in Guizhou Province as the engineering background, through the establishing the multi-field coupling model of gas flow in coal mining face under high temperature field, the gas drainage effect of coal seam boreholes under different heating temperature, borehole diameter and borehole spacing conditions was simulated and studied. The research shows that temperature has a significant impact on the effect of coal seam gas emission. When the heating temperature is 86 ℃, the gas pressure decreases significantly; the borehole diameter has a great influence on the effect of coal seam gas emission. When the borehole diameter is 113 mm, the maximum gas pressure between boreholes is 0.36 MPa, the maximum gas pressure decreases by 14.28% year on year, and the gas emission from boreholes increases by 27.27%. The effect of borehole spacing on coal seam gas pressure and discharge effect is also very obvious. When the borehole spacing is 1 m, the maximum gas pressure between boreholes is 0.45 MPa, and the influence range is 5.72 m. The decrease range of gas pressure increased by 37.8% compared with the hole spacing of 1.5 m and the influence range increased by 18.18% compared with the hole spacing of 1.5 m. The comprehensive gas discharge effect was the best. Comparing the simulation results of different schemes, the numerical simulation scheme 9 has the best gas emission effect.

       

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