极近距离上邻近层瓦斯抽采试验研究

发布时间：2018-10-16 21:18

【摘要】：为积极应对国家禁止“U+L”型通风方式所带来的工作面瓦斯治理困局,兴无煤矿42207工作面进行“U+L”型通风方式改Y型通风方式瓦斯抽采试验研究,工作面通风方式改变后,其风排瓦斯能力大幅度下降,为了防止瓦斯超限,需要加大工作面瓦斯抽采量。本文基于42207工作面上部存在随采随冒的极近距离上邻近层4上煤层的实际情况,在42207工作面进行极近距离上邻近层瓦斯抽采试验,探究行之有效的极近距离上邻近层瓦斯抽采方法。本文借助COMSOL Multiphysics软件模拟分析了矿井工作面分别开挖20m、40m、60m、80m、100m时其前方煤岩体应力分布情况,且首次将模拟开挖高度定为工作面懫高和冒落带高度之和,模拟结果表明:工作面前方煤岩体存在超前卸压效应,且极近距离上邻近层的超前卸压带宽度为15m。通过现场超前卸压带宽度测试实验,验证了工作面前方煤岩体存在超前卸压效应,所实测的超前卸压带宽度为18.26m,与模拟结果基本一致,验证了模拟的合理性,并分析了二者产生差异性的原因,为极近距离上邻近层瓦斯抽采试验提供了理论支撑与现场依据。在42207工作面施工的定向水平长钻孔试验孔,可以在极近距离上邻近层4上煤层冒落到工作面之前对其超前卸压瓦斯进行有效抽采,抽采效果表明:钻孔平均抽采浓度分别为12%和36%,平均抽采纯量分别为0.46m3/min和0.74 m3/min;最大瓦斯抽采浓度能达到了63.03%,最大单孔瓦斯抽采纯量达到了1.86 m3/min,抽采效果显著。根据试验结果,所施工的极近距离上邻近层瓦斯抽采长钻孔可有效地抽采极近距离上邻近层超前卸压瓦斯,能在很大程度上解决工作面上隅角和回风流瓦斯超限问题,减小通风压力,降低采空区瓦斯涌出,保障工作面安全生产。
[Abstract]:In order to deal with the gas control difficulties caused by the ban of "U L" type ventilation mode, the gas drainage test of "U L" type ventilation mode to Y type ventilation mode is carried out in Xingwu coal mine 42207 working face. After the ventilation mode is changed, the gas drainage capacity of the working face is greatly reduced. In order to prevent the gas from exceeding the limit, it is necessary to increase the amount of gas drainage in the working face. Based on the fact that the upper part of the 42207 working face has the upper coal seam of the upper adjacent layer 4 with the caving, the gas extraction test of the very close distance upper adjacent bed is carried out at 42207 face. To explore the effective method of gas extraction from the upper adjacent strata in very close distance. In this paper, the stress distribution of coal and rock mass in front of coal face is simulated and analyzed with the help of COMSOL Multiphysics software, and the simulated excavation height is determined as the sum of the height of the face and the height of the caving zone for the first time. The simulation results show that there is a pressure-relief effect in the coal and rock mass in front of the working face, and the width of the pressure-relief zone in the adjacent strata is 15m at very close distance. Based on the field test of the width of the pressure-relief zone, it is verified that there is a pressure-relief effect in the coal and rock mass in front of the working face. The measured width of the zone is 18.26 m, which is basically consistent with the result of simulation, which verifies the rationality of the simulation. The reasons for the difference between the two are analyzed, which provides theoretical support and field basis for the gas extraction test of the adjacent strata in very close distance. The directional and long horizontal borehole test hole constructed in 42207 working face can be used to extract the pressure-relief gas in advance before the coal seam on the top of the adjacent layer 4 falls into the working face at very close distance. The results show that the average extraction concentration of borehole is 12% and 36%, the average extraction scalar is 0.46m3/min and 0.74 m3 / min respectively, the maximum gas extraction concentration is 63.03 and the maximum single hole gas extraction is 1.86 m3 / min, and the extraction effect is remarkable. According to the test results, the long borehole of gas extraction in the very close distance and upper adjacent strata can be used effectively to extract the gas in advance from the very close distance of the upper adjacent strata, and to a great extent to solve the problem of the upper corner angle of the working face and the gas overrun problem of the return air flow. Reduce ventilation pressure, reduce gas emission from goaf and ensure safe production.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD712.6

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