采空区瓦斯封存量计算方法研究

发布时间：2018-05-14 19:56

本文选题：采空区 + 瓦斯封存量　；参考：《青岛理工大学》2013年硕士论文

【摘要】：CH_4是第二大温室气体，煤炭开发中的瓦斯涌出是大气中CH_4的重要来源之一，煤炭开发过程中的碳排放日益引起人们的关注。采空区中封存着大量的瓦斯，计算采空区中的封存瓦斯量有助于碳排放量的准确计算，并为制订节能减排措施提供依据。采空区封存瓦斯量主要受采空区空间体积和采空区瓦斯浓度分布两方面的因素影响。而采空区空间体积由采空区上覆岩层的垮落特征决定的；采空区瓦斯浓度分布是由采空区的瓦斯运移特征决定的。本论文在对晓明煤矿的上覆岩石参数和采空区的瓦斯浓度进行了实际测定的基础上，运用RFPA2D软件对采空区上覆岩层的垮落过程进行了模拟，运用FLUENT软件对采空区瓦斯浓度场进行了模拟，，借助岩体力学、岩层与地表移动、矿井瓦斯涌出量预测等相关基础理论推导出了采空区瓦斯封存量的计算公式，并进行了实际计算和验证。本论文主要有以下几个方面的内容：（1）本论文梳理了竖向冒落带、裂隙带、弯曲下沉带，横向自然堆积区、承压稳定区、压实稳定区的特征，调研分析了晓明煤矿和大兴煤矿的实际“三带”观测资料，对晓明煤矿上覆岩层的物理参数进行了测定，运用RFPA~(2D)软件对晓明煤矿N_2413回采工作面采空区的上覆岩层垮落过程进行了模拟，得到了采空区横竖三区（带）的特征、范围规律。（2）系统地分析了采空区瓦斯的来源，引入多孔介质的概念，并以流体的连续性方程、运动方程、动量方程为基础，列出了采空区瓦斯渗流的数学模型，并给出了三类边界条件。对晓明煤矿的N_2413回采工作面采空区瓦斯浓度分布规律进行了实际测量，运用FLUENT软件模拟了晓明煤矿N_2413回采工作面采空区瓦斯浓度场，得出了采空区的瓦斯浓度场。（3）以采空区的上覆岩层垮落特征和采空区瓦斯浓度场特征为基础，提出了采空区瓦斯封存量计算模型，对计算公式进行了推导。（4）以铁法矿区晓明煤矿N_2413回采工作面的具体条件为背景计算出了现有采空区的封存瓦斯量，并对公式的计算准确性进行了验证。
[Abstract]:CH_4 is the second largest greenhouse gas, and the gas emission from coal development is one of the important sources of CH_4 in the atmosphere. There is a large amount of gas in the goaf. The calculation of the gas sequestration in the goaf is helpful to the accurate calculation of carbon emissions and provides the basis for the formulation of energy saving and emission reduction measures. The amount of gas sealed in goaf is mainly affected by the space volume of goaf and the distribution of gas concentration in goaf. The space volume of the goaf is determined by the collapse characteristics of the overlying strata in the goaf, and the gas concentration distribution in the goaf is determined by the gas migration characteristics of the goaf. Based on the actual measurement of the overlying rock parameters and the gas concentration in the goaf of Xiaoming Coal Mine, the collapse process of the overlying strata in the goaf is simulated by using RFPA2D software. The gas concentration field in goaf is simulated by FLUENT software. Based on the basic theories of rock mass mechanics, rock strata and surface movement, and gas emission prediction in coal mine, the calculation formula of gas sealing capacity in goaf is deduced. The actual calculation and verification are carried out. The main contents of this thesis are as follows: 1) in this paper, the characteristics of vertical caving zone, fracture zone, bending and sinking zone, transverse natural accumulation area, pressure stable zone and compaction stability zone are combed, and the actual "three zones" observation data of Xiaoming Coal Mine and Daxing Coal Mine are investigated and analyzed. The physical parameters of overlying strata in Xiaoming Coal Mine are measured, and the overlying strata collapse process in the goaf of N2413 stoping face of Xiaoming Coal Mine is simulated by using RFPA-2D software, and the characteristics and range of the three areas (zones) of goaf are obtained. The source of gas in goaf is analyzed systematically, the concept of porous medium is introduced, and based on the continuity equation, motion equation and momentum equation of fluid, the mathematical model of gas seepage in goaf is listed, and three kinds of boundary conditions are given. The distribution law of gas concentration in goaf of Nji 2413 mining face in Xiaoming coal mine is measured in practice. The gas concentration field in goaf of N2413 mining face of Xiaoming coal mine is simulated by FLUENT software, and the gas concentration field of goaf is obtained. Based on the characteristics of overlying rock strata and gas concentration field in goaf, a calculation model of gas storage in goaf is put forward, and the calculation formula is deduced. (4) based on the concrete conditions of NSP 2413 mining face in Xiaoming Coal Mine of Tiefa Mining area, the amount of gas sealed in the existing goaf is calculated, and the calculation accuracy of the formula is verified.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD712

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