【作者】 王超；

【导师】 张雷林；

【作者基本信息】 安徽理工大学 ， 安全工程， 2019， 硕士

【摘要】 随着煤炭开采朝纵深向发展,瓦斯超限和遗煤自燃问题十分突出,并成为制约井下安全生产的两大主要危害。本论文结合保德煤矿81307工作面综合机械化放顶煤采煤工艺的实际情况,依据煤自然发火特性和影响因素、多孔介质理论、采空区气体渗流及扩散规律、渗流控制方程等基础理论,结合实验室试验、数值模拟、现场实测的方法,对有无埋管抽采及抽采管不同埋深条件下,采空区自然发火规律进行研究。研究表明:（1）通过现场采集81307工作面煤样,进行煤自然发火低温氧化试验。在不同供氧条件下,对煤自燃过程产物进行优选,分析标志性气体CO和C₂H₄产生规律,确定该工作面煤层能维持自然发火的氧气浓度下限为8%,为之后采空区自燃“三带”的划分指标给予参考。（2）根据煤层上覆岩层特性及采空区冒落的一般规律,通过质量、动量、能量及组分运输的方程来构建采空区气体渗流及扩散数学模型,确定孔隙率、粘性阻力系数和惯性阻力系数的等相关参数。利用ANSYS FLUENT软件模拟无抽采、埋深20m、埋深60m、埋深100m四种情况下,采空区自燃带变化规律。（3）通过现场布置测点,采集测点气样及温度,分析O₂、温度的变化规律,得出在联巷埋管抽采条件下,采空区遗煤自燃“三带”的范围:小于105m为散热带,105²70m为氧化带,大于270m为窒息带。与数值模拟相互验证,误差在允许范围内,表明模拟的正确性。本文主要研究内容对煤与瓦斯共存且采用联巷埋管抽采方式的综放工作面,提供了参考依据;同时,对保证采空区抽采效果,兼顾防治遗煤自燃,保障井下作业安全有序的进行具有一定的应用价值。图[29]表[10]参[63]更多还原

【Abstract】 With the development of coal mining in depth,the problems of gas exceeding the limit and coal spontaneous combustion are very prominent,and become two major hazards restricting the safety of underground production.This paper combines the actual situation of the comprehensive mechanized caving coal mining technology in81307 working face of Baode Coal Mine,and uses the basic theories of coal spontaneous combustion process and influencing factors,porous medium theory,gas seepage and diffusion law in goaf,and seepage control equation.Through the methods of test analysis,numerical simulation and field measurement,to study the spontaneous combustion law of goaf in the presence or absence of buried pipe extraction and different depths of the extraction pipe.The results show that:（1）Through collecting coal samples from 81307 working face on site,the low temperature oxidation test of coal spontaneous combustion was carried out.Under different oxygen supply conditions,the product of coal spontaneous combustion process was optimized,and the regularity of production of CO and C2H4 was analyzed.The lower limit of oxygen concentration which can maintain spontaneous combustion in coal seam was determined to be 8%,which can be used as a reference for dividing the"three zones"of spontaneous combustion in goaf.（2）According to the characteristics of the overlying strata and the general law of the caving of the goaf,the mathematical model of gas seepage and diffusion in the goaf is constructed by the equations of mass,momentum,energy and component transport,and the related parameters such as porosity,viscous resistance coefficient and inertia resistance coefficient are calculated.The ANSYS FLUENT software was used to simulate the variation of the spontaneous combustion zone in the goaf under the four conditions of no extraction,buried depth 20m,buried depth 60m and buried depth100m.（3）By arranging measuring points on site,collecting gas samples and temperature,and analyzing the variation rule of O₂ and temperature,it is concluded that the"three zones"of spontaneous combustion in goaf are less than 105 m as heat sink zone,105²70 m as oxidation zone and 270 m as asphyxiation zone under the condition of combined tunnel extraction.Compared with the numerical simulation results,the error is within the allowable range,which verifies the accuracy of the simulation results.The main research contents of this paper provide a reference basis for fully mechanized caving face with coal and gas coexisting and adopting combined tunnel buried pipe extraction method;at the same time,it has certain application value for guaranteeing the effect of goaf extraction,taking into account the prevention and control of residual coal spontaneous combustion,and ensuring the safe and orderly underground operation.Figure[29]Table[10]Reference[63]更多还原