高瓦斯超长综放面瓦斯抽放技术研究与应用

发布时间：2018-10-10 13:04

【摘要】：由于我国煤层瓦斯具有低浓度、低压力、低渗透的“三低”特性,煤矿瓦斯从源头来源治理有三个方面,本煤层瓦斯治理、采空区瓦斯治理和临近层瓦斯治理。而综放开采因具有产量大、成本低、效益好等优点,在我国广泛应用,随之而来的采空区遗煤量大造成采空区瓦斯浓度较高等问题愈发严重,不仅影响生产而且危及员工安全。瓦斯抽放能从根本上解决煤矿瓦斯问题,而采空区瓦斯问题通过改变通风方式来解决是比较节约成本的一种有效方法。因此本文在推导本煤层瓦斯运移扩散公式的基础上,借助于COMSOL Multiphysics数值模拟软件来模拟不同抽放时间、抽采孔径、抽采负压、抽采孔间距、围岩压力对抽采效果或孔隙率和渗透率的影响,来找到适合的瓦斯抽放参数;不同通风方式对采空区瓦斯浓度的影响;模拟高抽巷的高度与理论公式计算的比对,最后在工程实践的监测值来对比研究。抽采时间在180d以前抽采效果较此后抽采效果好,抽采孔径为120mm,抽采负压为10kPa,抽采孔间距为5m。上隅角和工作面瓦斯超限问题也是利用改变通风方式的方法来解决,模拟采空区瓦斯浓度的变化确定通风方式为“Y+高抽巷型。通过计算得到周期来压步距为8.8m-11.7m,采空区三带中的冒落带的高度为11.8m-18.lm,数值模拟得到高度为15.5m,确定UDEC数值模拟软件的模拟开挖距离为20m,模拟出三带高度与公式对比相吻合,在现实应用中的监测数值钻屑瓦斯解吸指标Kmax值最大为0.38;钻屑量Smx最大值为2.4 kg/m;瓦斯浓度W小于8m3/t,均符合标准要求。
[Abstract]:Because coal seam gas in China has the characteristics of low concentration, low pressure and low permeability, there are three aspects of coal mine gas treatment from source, this coal seam gas treatment, goaf gas treatment and adjacent gas treatment. Due to the advantages of large output, low cost and good benefit, fully mechanized caving mining is widely used in our country, and the following problems such as high gas concentration in goaf caused by the large amount of coal left in goaf are becoming more serious, which not only affect production but also endanger the safety of employees. Gas drainage can fundamentally solve the problem of coal mine gas, and the gas problem in goaf can be solved by changing the ventilation mode, which is an effective method to save cost. Therefore, on the basis of deducing the formula of gas migration and diffusion in coal seam, this paper simulates different drainage time, extraction aperture, suction negative pressure, extraction hole spacing by means of COMSOL Multiphysics numerical simulation software. The influence of surrounding rock pressure on the extraction effect or porosity and permeability to find suitable gas drainage parameters; the influence of different ventilation methods on gas concentration in goaf; the comparison between the height of simulated high drainage roadway and the calculation of theoretical formula, Finally, the monitoring value of engineering practice is compared and studied. The extraction time before 180 days is better than that before 180 days, the extraction aperture is 120 mm, the suction negative pressure is 10 KPA, and the interval between the pumping holes is 5 m. The problem of gas over-limit in upper corner and working face is also solved by changing the ventilation mode. The simulation of gas concentration in goaf determines that the ventilation mode is "Y high drainage roadway". By calculation, the interval of periodic compression is 8.8m-11.7m, the height of falling zone is 11.8m-18.lm, the height of numerical simulation is 15.5 m, the simulated excavation distance of UDEC numerical simulation software is 20m, and the height of three zones is consistent with the formula. In practical application, the maximum value of Kmax is 0.38 and the maximum value of Smx is 2.4 kg/m; gas concentration W < 8m3 / t, which accords with the standard requirement.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD712.6

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