急倾斜高瓦斯综放开采采空区自然发火机理及防治研究

发布时间：2019-06-06 06:41

【摘要】：随着我国一些矿区老化与开采深度不断增大,煤层开采条件越来越复杂,急倾斜、高瓦斯、深部开采成为必然。据统计在我国煤炭资源中,急倾斜煤层的储量占煤炭总储量的4%,南方地区80%的矿区赋存有急倾斜煤层。而在开采方法上,部分急倾斜矿井为提高开采强度与产量,探索采用综放开采方式。综放开采由于一次开采强度大,冒落高度大,采空区残煤多,漏风严重,使得采空区自然发火危险性增加。论文以急倾斜高瓦斯综放开采采空区自然发火问题作为在研究对象,结合现场实际,找到防治这类矿井自然发火的有效措施。预防煤炭自燃,首先必须对煤的自然倾向性进行研究。论文在分析了我国现行鉴定方法的局限性基础上,提出采用热分析技术和活化能理论相结合的方法,采用热重、红外和质谱联用的方式,运用动力学机制模型函数,全面分析煤的低温氧化反应能力和氧化热解过程,确定指标气体、特征温度、求解活化能,分析煤的自燃倾向性。对于有自燃倾向性的急倾斜高瓦斯综放工作面,必须对采空区流场的气体运移规律进行深入分析。论文针对这类采空区流场特点,应用多孔介质的理论,建立采空区三维非均质流场数学模型。采空区气体流动服从Darcy定律、连续方程和动量方程。在对急倾斜采空区渗流系数进行确定及优化的基础上,应用CFD技术,对气体组分动力弥散现象及其机理进行分析,建立采空区气体组分动力弥散方程,并对采空区流场进行仿真。在煤炭自然发火监测上,提出将测温法与标志气体分析法相结合。通过优化监测工艺、测点布置和监测指标等实现全面、快速、准确的监测与监控。在对采空区“三带”划分上,结合急倾斜综放面采空区遗煤的分布特点和三带划分的影响因素,提出急倾斜综放面采空区自燃“三带”划分指标,明确急倾斜综放面采空区的“三带”分布趋势与特点。最后通过模拟、实验以及现场测试等手段,确定采空区自然发火测控参数,提出有效的防灭火综合技术。特别是在动态调风中,针对瓦斯与火进行了风量耦合计算,对于出现的不可调和矛盾,采取瓦斯抽采、注氮防灭火等技术措施进行控制。并对瓦斯抽采及注氮防灭火的相关技术参数、对采空区“三带”的影响等进行分析和模拟,保证急倾斜高瓦斯矿井的瓦斯与火的安全性。经过实践应用,取得较好应用效果。
[Abstract]:With the aging and mining depth of some mining areas in China, coal seam mining conditions are becoming more and more complex, steeply inclined, high gas, deep mining is inevitable. According to statistics, the reserves of steeply inclined coal seams account for 4% of the total coal reserves in China, and 80% of the mining areas in southern China have steeply inclined coal seams. In the mining method, in order to improve the mining intensity and production, some steeply inclined mines adopt fully mechanized top coal caving mining method. Due to the high intensity of primary mining, large caving height, more residual coal and serious air leakage in goaf, the risk of spontaneous combustion in goaf is increased. In this paper, the problem of spontaneous combustion in goaf of steeply inclined high gas fully mechanized caving mining is taken as the research object, and the effective measures to prevent and control spontaneous combustion in this kind of mine are found according to the actual situation in the field. In order to prevent spontaneous combustion of coal, the natural tendency of coal must be studied first. Based on the analysis of the limitations of the current identification methods in China, this paper puts forward the method of combining thermal analysis technology with activation energy theory, the combination of thermogravimetric, infrared and mass spectrometry, and the use of kinetic mechanism model function. The oxidation ability and pyrolysis process of coal at low temperature are analyzed comprehensively, the index gas and characteristic temperature are determined, the activation energy is solved, and the spontaneous combustion tendency of coal is analyzed. For the steeply inclined high gas fully mechanized caving face with spontaneous combustion tendency, the gas migration law of the goaf flow field must be deeply analyzed. According to the characteristics of this kind of goaf flow field, the mathematical model of three-dimensional heterogeneous flow field in goaf is established by using the theory of porous media. The gas flow in goaf obeys Darcy's law, continuity equation and momentum equation. On the basis of determining and optimizing the seepage coefficient of steeply inclined goaf, the dynamic dispersion phenomenon and mechanism of gas components are analyzed by using CFD technique, and the dynamic dispersion equation of gas components in goaf is established. The flow field in goaf is simulated. In the monitoring of coal spontaneous combustion, the combination of temperature measurement method and marked gas analysis method is put forward. Comprehensive, rapid and accurate monitoring and monitoring are realized by optimizing monitoring technology, layout of measuring points and monitoring indexes. On the division of "three zones" in goaf, combined with the distribution characteristics of residual coal in goaf of steeply inclined fully mechanized caving face and the influencing factors of the division of three zones, the classification index of "three zones" of spontaneous combustion in goaf of steeply inclined fully mechanized caving face is put forward. The distribution trend and characteristics of "three zones" in goaf of steeply inclined fully mechanized caving face are clarified. Finally, by means of simulation, experiment and field test, the measurement and control parameters of spontaneous combustion in goaf are determined, and an effective comprehensive technology of fire prevention and extinguishing is put forward. Especially in the dynamic air regulation, the coupling calculation of air volume between gas and fire is carried out, and the technical measures such as gas extraction, nitrogen injection and fire prevention and extinguishing are adopted to control the irreconcilable contradiction. The related technical parameters of gas extraction and nitrogen injection fire prevention and extinguishing are analyzed and simulated, and the influence of "three zones" in goaf is analyzed and simulated to ensure the safety of gas and fire in steeply inclined high gas mine. Through practical application, good application effect has been obtained.
【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TD752.2

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