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1、论文题目：高瓦斯煤层抽放条件下综放采空区自燃预测研究专 业：安全技术及工程硕 士 生：陈明河 （签名） 指导教师：徐精彩 张辛亥 （签名） 摘 要我们国家煤炭资源十分丰富，煤炭产量和消费量均居世界首位，但我国煤炭自燃火灾十分严重，严重制约了矿井的安全生产与发展，造成巨大的资源浪费、环境污染、人员和财产的损失。高瓦斯厚煤层综放开采情况下，煤层自燃更加严重，危害也更大。受抽放影响，采空区漏风更加复杂，自燃预测和防治困难。首先，利用大型煤自然发火实验台对煤的自燃特性进行了实验研究，测定了煤自燃在不同温度下的耗氧速度，CO和CO2的产生率，氧化放热强度以及自燃极限参数等，为自燃预测预报奠定了基础；其次
2、，对高瓦斯煤层综放工作面进行了现场观测，得到了抽放条件下采空区上、下巷的氧气、甲烷浓度及压力分布规律，分析得到采空区渗透系数随深度变化方程，通过现场实验得到采空区冒落带的高度分布规律，据此建立了高瓦斯煤层抽放条件下采空区渗流场和浓度场的三维模型；然后，利用流体计算软件FLUENT对高瓦斯自燃煤层抽放条件下的综放采空区进行网格划分并对采空区渗流场和浓度场模型进行求解，得到高瓦斯煤层抽放条件下综放采空区漏风状况及各组分气体浓度分布，数值模拟结果与现场实际基本吻合；最后，根据模拟结果，结合采空区三带划分理论，对高瓦斯煤层抽放条件下采空区自燃危险区进行判定，对自燃危险期进行预测，并计算出防止采空区自燃
3、的工作面最小推进度。研究结果对高瓦斯煤层抽放条件下综放采空区自燃防治具有重要意义。关 键 词：高瓦斯煤层；抽放；采空区；自然发火；预测；模拟论文类型：应用研究Subject : Research on Prediction of Self-ignition in Goaf of FullyMechanized Top-Coal Face in High-Gas Coal Seams under the Condition of Gas Extraction Specialty : Safety EngineeringName : Chen Minghe (Signature) Instruct
4、or: Xu JingcaiZhang Xinhai (Signature) ABSTRACTCoal resource is very abundant and output and consumption of coal in China ranked No one out of all countries in the world. Nevertheless, Coal self-ignition fire is very serious, which threatened safety production and caused enormous resource waste, env
5、ironment pollution, loses of personnel. Self-ignition becomes more serious and harmful in high-gas and thick coal seams, especially in fully mechanized top-coal face, where air leakage is more complex and makes prediction and prevention of self-fire in the goaf more difficult.Firstly, the large expe
6、riment device of coal self-ignition is used to study the character, evaluate oxygen consuming rate, calculate CO and CO2 generating rate and heat releasing intensity of coal self-ignition. Critic parameters for spontaneous combustistion of oxgen concentration, loose coal thickness and air leakage in
7、tensity can also be studied through the experiment;Secondly, on-the-spot observation in the goaf of fully mechanized top-coal face in high-gas coal seam during the course of gas extraction are carried out, distribution of oxygen concentration, methane concentration and pressure in the goaf near the
8、two laneways, and of pemeability in different places in the goaf are obtained. Distribution laws of collapsed height in the goaf are also obtained by on-the-spot observation. A three-dimension model of the flow, osmosis and concentration in the goaf of the high gas coal seam during the course of ext
9、racting gas are set up; Thirdly, the numeric model of air leakage and consistency in goaf of fully mechanized top-coal face in high-gas coal seams on condition of extracting gas is solved by using CFD software FLUENT. Distribution regulations of air leakage intensity and species concentration in goa
10、f of fully mechanized top-coal face in high-gas coal seams on condition of gas extraction are obtained which are identical on the whole to what from on-the-spot observation; Finally, the results of numeric modeling together with “three zone” theory are used to divide in goaf, the danger zone of coal
11、 self-ignition on condition of extracting gas, to predict the danger time of coal self-ignition and to calculate minimum velocity of mining to prevent coal from self-ignition in goaf are calculated. The result of the study is important for preventing coal self-ignition in goaf of fully mechanized to
12、p-coal face in high-gas coal seams during the course of extracting gas.Key words : High Gas Coal Seams, Extracting Gas, Goaf, Self-ignite, Forecast, Model Thesis : Application Research目 录目 录1 绪论11.1 问题的提出11.2 国内外研究现状21.2.1煤的自燃危险性预测的研究进展21.2.2 煤自燃危险区域判定理论41.2.3 煤层自然发火期预测51.2.4 煤自然发火数学模型及数值模拟61.2.5 存在
13、问题71.3 本文研究内容71.4 研究方法及技术路线82 煤层自燃特性参数实验测试92.1 实验原理92.2 实验台结构92.3 实验条件122.4 实验结果及分析122.4.1实验结果122.4.2结果分析132.5 实验结论212.6 本章小结213 高瓦斯煤层抽放条件下现场观测及自然发火预测模型233.1 高瓦斯煤层抽放条件下综放采空区现场观测233.1.1 高瓦斯煤层抽放条件下工作面现场观测结果分析233.1.2 高瓦斯煤层抽放条件下综放采空区冒落带特点263.1.3煤层采空区相关假设293.1.4 巷道两侧氧气和瓦斯浓度的数据拟合303.2松散煤体内的传质和采空区渗流参数303.2
14、.1松散煤体内的传质313.2.2空隙率及渗透系数363.2.3采空区两道及工作面压力分布383.3采空区内传值及渗流和扩散数学模型393.3.1采空区渗流控制方程393.3.2采空区氧浓度场和瓦斯浓度场数学模型403.4 采空区自然发火预测模型403.5 本章小结424 高瓦斯煤层抽放条件下综放采空区漏风状况数值模拟434.1 高瓦斯煤层抽放条件下综放采空区三维物理模型建模434.2 FLUENT软件特征及使用444.2.1 FLUENT软件构成454.2.2 FLUENT软件能力及适用对象464.2.3 FLUENT使用的单位制474.2.4 FLUENT使用的文件类型474.2.5 FL
15、UENT求解484.2.6 求解器的选择494.3 计算区域网格划分504.4模拟结果分析及三带划分504.4.1 高瓦斯煤层抽放条件下自然发火数值模拟结果分析504.4.2 采空区浮煤自燃极限参数564.4.3 采空区遗煤自燃危险区域判定条件584.4.4 采空区自燃危险区域划分方法和步骤594.4.5 抽放条件下采空区自燃“三带”划分604.4.6结果分析624.5本章小结625 结论635.1 主要结论635.2 今后工作展望64致 谢65参考文献66附 录69I1 绪论1 绪论1.1 问题的提出煤自燃是自然界存在的一种客观现象，这种现象已经存在了数百万年。在煤层开采的过程中，我国大约有二分之一的国有矿井存在自然发火危险，每年由于自燃造成的直接和间接经济损失近百亿元1。矿井自燃火灾产生大量有毒
