【作者】 刘斌；

【导师】 王飞； 王永文；

【作者基本信息】 太原理工大学 ， 安全工程（专业学位）， 2021， 硕士

【摘要】 在煤矿生产中,瓦斯灾害常常是引发事故最大的原因,因此瓦斯来源以及其防治技术也是关乎矿井安全生产的重中之重。本文在分析和总结前人关于采空区瓦斯来源以及工作面上隅角瓦斯治理技术的基础上,针对宜兴煤业一采区1202综采工作面上隅角瓦斯超限所导致工作面停产以及采空区瓦斯来源等问题,通过现场取样分析检测等技术手段,利用稳定碳氢同位素分源法并提出采空区瓦斯来源计算模型,预测各临近煤层和本煤层对1202采空区瓦斯贡献率。根据分源预测结果,提出采空区瓦斯分源治理措施,运用FLUENT模拟软件对采空区不同的瓦斯治理方式进行模拟,综合考虑决定使用采取上隅角埋管抽采瓦斯治理方式,解决上隅角瓦斯超限问题。在研究过程中主要取得以下成果:(1)利用稳定碳氢同位素值进行碳氢同位素标记,对1202综采工作面采空区混合瓦斯进行来源定量分析,并提出瓦斯分源计算模型。(2)根据单日与单月分源预测结果表明,对于1202综采工作面采空区2_下~#煤层瓦斯来源占比最大,达到52.72%左右,2~#煤层和3~#煤层瓦斯贡献率平均分别为24.53%、16.52%,而1~#煤层瓦斯贡献率起伏变化不大,稳定在6.24%左右,因此1202瓦斯防治的重点是2_下~#煤层,2+3~#煤层辅助防治。(3)在采空区多孔介质理论体系研究基础上,建立了在采空区与工作面的瓦斯流动的数学模型,使用FLUENT数值模拟软件对1202回采工作面采空区瓦斯的不同抽采方式对采空区内部瓦斯气体运移进行数值模拟分析。结果表明:埋管条件下,上隅角瓦斯浓度与未抽采时相比瓦斯浓度降低28%,工作面上隅角瓦斯浓度下降到0.45%左右;模拟埋管加长距离高位钻孔联合布置时,采空区深部区域的瓦斯浓度也得以被大大减弱,抽采之后瓦斯浓度下降45%,工作面上隅角瓦斯浓度下降到0.35%左右。(4)对现场进行抽采试验结果表明,抽采期间上隅角平均瓦斯浓度降到了0.40%,抽采纯量稳定在8.03m~3/min左右,抽采负压维持在12.37Kpa左右,上隅角与回风巷平均瓦斯浓度分别降到了0.48%、0.31%,与模拟结果相差不大,基本一致。虽然使用埋管抽采可以有效降低上隅角瓦斯浓度,达到安全生产水平,但根据模拟效果建议还是采取埋管和高位钻孔联合布置抽采方式可以从根源上有效防治瓦斯。更多还原

【Abstract】 In coal mine production,gas disasters are often the biggest cause of accidents.Therefore,the source of gas and its prevention technology are also the top priorities of mine safety production.Based on the analysis and summary of predecessors on the gas source in the goaf and the gas treatment technology at the upper corner of the working face,this article aims at the stop of production and the stop of the working face caused by the excessive gas in the upper corner of the 1202 fully-mechanized working face in Yixing Coal Industry No.1 mining area.For gas sources in the goaf,we use on-site sampling,analysis and testing and other technical means,use the stable hydrocarbon isotope separation method and propose a gas source calculation model in the goaf to predict the contribution rate of each adjacent coal seam and this coal seam to the gas in the 1202 goaf.According to the prediction results of separate sources,the gas source separation control measures in the goaf were proposed,and the FLUENT simulation software was used to simulate different gas control methods in the goaf.After comprehensive consideration,it was decided to adopt the upper corner buried pipe drainage gas control method to solve the above problems.Corner gas overrun problem.The following results were mainly achieved during the research process:(1)The source of mixed gas in goaf of 1202 fully-mechanized mining face was quantitatively analyzed by using stable carbon and hydrogen isotopic markers,and the calculation model of gas source separation was proposed.(2)The single-day and single-month forecast results showed that the 2~#coal seam in the goaf of 1202 fully mechanized mining face accounts for the largest proportion of gas sources,reaching about 52.72%.The average gas contribution rate of 2~#coal seam and 3~#coal seam was24.53%and 16.52%,respectively,while the gas contribution rate of 1~#coal seam had little fluctuations and stabilized at about 6.24%.Therefore,the 1202 gas prevention and control are the focus of the 2~#coal seam under,and 2+3~#coal seam auxiliary prevention and control.(3)Based on the study of the goaf porous media theory system,a mathematical model of gas flow between the goaf and the working face was established.The different methods of gas drainage in the goaf of 1202 working face were used to simulate and analyze the gas migration inside the goaf by using the FLUENT numerical simulation software.The results showed that under the condition of buried pipe,the gas concentration in the upper corner is reduced by 28%compared with that without extraction,and the gas concentration in the corner of the working face is reduced to 0.45%.When the simulated buried pipe was lengthened and the high-position borehole is jointly arranged,the gas concentration in the deep area of the goaf can be greatly weakened.After extraction,the gas concentration reduced by 45%,and the gas concentration in the corner of the working face reduced to 0.35%.(4)The field drainage test results showed that during the drainage period,the average gas concentration in the upper corner decreased to 0.40%,the extraction pure quantity was stabilized at about 8.03m~3/min,the suction negative pressure was maintained at about 12.37k Pa,and the average gas concentration in the upper corner and the return air roadway decreases to 0.48%and 0.31%respectively,which is basically consistent with the simulation results.Although the use of buried pipe drainage can effectively reduce the gas concentration in the upper corner and reach the safety level of production,according to the simulation results,it is suggested to adopt the combined arrangement of buried pipe and high-level borehole to effectively control gas fundamentally.更多还原