高位巷抽采负压对瓦斯及煤自燃协同防治的影响
Influence of Negative Pressure in High Level Roadway on Coupling Hazard Prevention of Gas and Coal Fire in Gob
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摘要: 高位巷抽采负压为影响采空区瓦斯及煤自燃复合灾害防治的关键因素之一,为确定合理的抽采负压,结合某矿401102综放工作面瓦斯易超限及自然发火实际情况,采用ANSYS数值模拟及现场实测方法,研究高位巷抽采负压对瓦斯抽采效果及煤自燃“三带”分布的影响,并进行工程实践。结果表明:抽采负压对采空区复合灾害防治有显著影响,负压由0.5 kPa增至3.5 kPa,瓦斯抽采纯量增加21.02 m3/min,相比“U”型通风,高位巷负压3 kPa时,氧化升温带宽进风侧扩大17 m,中部与回风侧分别缩小14 m和11 m;提出了合理抽采负压范围的界定方法,确定负压波动区间为0.951 6,2.558,最佳点为2.558 kPa。煤层采用高位巷抽采方式时,合理设定抽采负压能够保证采空区瓦斯及煤自燃灾害的耦合防治。Abstract: The negative pressure of high level roadway extraction is one key factor which can influence coal spontaneous combustion and the gas extraction, to determine the reasonable negative pressure of extraction, combined with the actual situation of gas over-limit and spontaneous ignition in 401102 fully mechanized caving face of a mine, ANSYS numerical simulation and field measurement method were adopted to study the influence of negative pressure of extraction in high level roadway on gas extraction effect and “three zones” distribution of coal spontaneous combustion, and engineering practice was carried out. The results show that negative pressure can result in coal spontaneous combustion. When negative pressure increases from 0.5 kPa to 3.5 kPa, gas extraction scalar increase by 21.02 m3/min, compared with the “U” ventilation mode, when the negative pressure of the high roadway was 3 kPa, the width of the oxidation heating zone increased by 17 m on the inlet side, and decreased by 14 m in the middle and 11 m on the return side; the method of defining the range of reasonable negative pressure of extraction was proposed, and the fluctuation range of negative pressure was determined between 0.951 6 and 2.558, and the optimal point was 2.558 kPa. When high level roadway is adopted in coal seam, the reasonable setting of negative pressure can ensure the coupling prevention and control of gas and coal spontaneous combustion in goaf.