【作者】 夏海斌；

【导师】 邓军； 肖蕾；

【作者基本信息】 西安科技大学 ， 安全技术及工程， 2011， 硕士

【摘要】 宁夏灵武矿区所开采煤层属于易自燃煤层,在开采过程中,综放工作面上隅角不同程度的出现CO气体,并且CO浓度时有超限。因此,掌握工作面采空区CO运移规律及浓度分布,对早期预测预报采空区遗煤自燃程度及治理工作面上隅角CO超限有非常重要的意义。本文以宁夏灵武矿区枣泉煤矿12207综放工作面为研究对象。首先,通过对枣泉煤矿2#煤层煤样进行程序升温实验,掌握了在实验条件下枣泉煤矿2#煤层煤样自燃特征温度以及不同粒度煤样在各个温度阶段产生CO的情况即CO生成量和CO产生速率,得出了不同温度下煤样的CO产生规律;其次,采用采空区预埋管抽样监测的手段得到采空区CO气体浓度随采空区深度变化的规律,结合理论分析和现场观测,得出综放工作面采空区压力、空隙率及渗透率的分布规律,建立了综放工作面采空区渗流场的物理和数学模型并对模型及其边界条件进行相应的合理简化。利用Fluent软件对综放工作面采空区流场进行数值模拟,得出采空区内部渗流速度及CO浓度的分布规律,进而得出了采空区CO运移规律。最后,结合实验和数值模拟数据得出了枣泉煤矿12207首采综放工作面采空区遗煤自燃程度判断依据,根据工作面上隅角CO浓度监测数据对采空区遗煤自燃程度进行了判断,得出了采空区遗煤的最高温度接近其自燃的临界温度65℃,实现了早期预测预报采空区遗煤自燃程度,也为治理工作面上隅角CO超限提供科学依据。更多还原

【Abstract】 The coal seam belongs to easily spontaneous combustion coal seam in Lingwu mining area Ningxia Hui Autonomous Region. In the mining process, CO gas comes out from the upper corners of fully mechanized and caved working faces in some coal mines, therefore the level of CO gas is often over the limit. It is necessary to research the concentration distribution and migration law of CO in the gob also has a very significant meaning of early predicting the degree to coal spontaneous combustion in gob and efficiently managing CO transfinite at the upper corners of working face.In this article,the NO. 12207 working face is researched in Zaoquan coal mine of Lingwu mining area, Ningxia Hui Autonomous Region. First of all, the characteristics temperature of coal’s spontaneous combustion and the quantity and rate of CO gas produced from coal samples at different temperatures condition, is carried out through the spontaneous combustion temperature-programmed experiment of samples from Zaoquan 2# coal seam at the experimental condition. The rules of CO generating from coal sample is obtained also; Secondly ,The distribution of CO gas concentration changes with depth in gob is acquired by means of buried pipe in the gob. The distribution of rock pressure, porosity, leakage channels and permeability of the gob are studied through theoretical analysis and field observation. Then a mathematical model of seepage and air species concentration is built and simplified by coordinately using the theory of heat and mass transfer in porous media. After that, distribution of CO concentration and the velocity of air flow in the gob are calculated by simulating the flow field using Fluent software numerically. Furthermore the migration law of CO in the gob is also obtained. Finally, the analysis of the intensity to spontaneous combustion of floating coal in the gob of the NO.12207 working face in Zaoquan coal mine is achieved through experimental and numerical simulation data. According to the monitoring data of CO concentration at the upper corner of working face, the degree to spontaneous combustion of floating coal in the gob is revealed: the maximum temperature of floating coal in the gob is close to its critical temperature of spontaneous combustion at 65℃,then it is successful to predict the degree to spontaneous combustion of floating coal in the gob and Provide scientific basis for managing CO transfinite at the upper corners of working face.更多还原