综放面采空区埋管抽采下瓦斯运移规律模拟研究
发布时间：2019-06-04 14:06
【摘要】：本文以流体力学、传质学、多孔介质流体动力学等理论为基础,结合石泉矿30101综放采空区现场实际,运用FLUENT软件,对埋管抽采条件下采空区瓦斯运移规律进行三维数值模拟研究。根据采空区冒落特征的一般规律,研究了采空区空隙率与渗透率的分布形式,给出了其呈“O”型圈分布的半经验公式；通过连续性方程、运动方程、扩散方程以及状态方程来构建基本方程组,建立了采空区混合气非线性渗流流态下的数学模型；对于该微分方程组,运用有限差分法(FDM)得到它的离散化方程组,引用交错网格,采用SIMPLE算法进行求解；借鉴FLUENT6.3用户指南中由Ergun公式推导粘滞阻力系数与惯性阻力系数公式的思想,对Bachmat多孔介质非线性渗流理论进行了分析,给出了采空区混合气非线性渗流粘滞阻力系数与惯性阻力系数公式；用数值模拟的方法,对比研究了重力作用、采空区“导气带”高度以及煤层倾角各因素对采空区瓦斯浓度分布的影响,得出在三维数值模拟中采空区瓦斯浓度分布是受这三个因素共同影响的结论；同时考虑这三个因素的影响,较真实地反映出采空区瓦斯浓度分布,对石泉矿30101综放采空区埋管抽采条件下的采空区瓦斯运移规律进行了研究,得到了抽采口埋深、抽采流量各自与抽采瓦斯浓度的函数关系,从瓦斯抽采利用和抽采效果的角度出发,给出采空区最佳抽采位置是抽采口埋深在25～35m范围内,采空区埋管最优抽采流量为17.1～18.4m3/min,为优化采空区瓦斯抽采参数提供了理论依据。
[Abstract]:Based on the theories of fluid mechanics, mass transfer and fluid dynamics of porous media, combined with the field practice of 30101 fully mechanized caving goaf in Shi Quan Mine, FLUENT software is used in this paper. The gas migration law in goaf under the condition of buried pipe pumping is studied by three-dimensional numerical simulation. According to the general law of caving characteristics of goaf, the distribution forms of voidage and permeability in goaf are studied, and the semi-empirical formula of "O" ring distribution is given. The basic equations are constructed by the continuity equation, the motion equation, the diffusion equation and the state equation, and the mathematical model under the nonlinear seepage flow pattern of the mixture in goaf is established. For the differential equations, the discretization equations are obtained by using the finite difference method (FDM). The staggered grid is used to solve the differential equations, and the SIMPLE algorithm is used to solve the equations. Based on the idea of deducing viscous resistance coefficient and inertia resistance coefficient formula from Ergun formula in FLUENT6.3 user's guide, the nonlinear seepage theory of Bachmat porous media is analyzed. The formulas of nonlinear seepage viscosity resistance coefficient and inertia resistance coefficient of mixture in goaf are given. The effects of gravity, the height of "gas conduction zone" in goaf and the dip angle of coal seam on the distribution of gas concentration in goaf are studied by means of numerical simulation. It is concluded that the gas concentration distribution in goaf is affected by these three factors in three-dimensional numerical simulation. At the same time, considering the influence of these three factors, the gas concentration distribution in goaf is truly reflected, and the gas migration law in goaf under the condition of 30101 fully mechanized caving goaf in Shi Quan Mine is studied, and the buried depth of goaf is obtained. The functional relationship between the drainage flow rate and the gas concentration is given. From the point of view of the utilization of gas extraction and the effect of gas extraction, it is given that the best extraction position in the goaf is that the depth of the pumping mouth is in the range of 25 m. The optimal drainage flow rate of goaf buried pipe is 17.1 鈮，
本文编号：2492772
[Abstract]:Based on the theories of fluid mechanics, mass transfer and fluid dynamics of porous media, combined with the field practice of 30101 fully mechanized caving goaf in Shi Quan Mine, FLUENT software is used in this paper. The gas migration law in goaf under the condition of buried pipe pumping is studied by three-dimensional numerical simulation. According to the general law of caving characteristics of goaf, the distribution forms of voidage and permeability in goaf are studied, and the semi-empirical formula of "O" ring distribution is given. The basic equations are constructed by the continuity equation, the motion equation, the diffusion equation and the state equation, and the mathematical model under the nonlinear seepage flow pattern of the mixture in goaf is established. For the differential equations, the discretization equations are obtained by using the finite difference method (FDM). The staggered grid is used to solve the differential equations, and the SIMPLE algorithm is used to solve the equations. Based on the idea of deducing viscous resistance coefficient and inertia resistance coefficient formula from Ergun formula in FLUENT6.3 user's guide, the nonlinear seepage theory of Bachmat porous media is analyzed. The formulas of nonlinear seepage viscosity resistance coefficient and inertia resistance coefficient of mixture in goaf are given. The effects of gravity, the height of "gas conduction zone" in goaf and the dip angle of coal seam on the distribution of gas concentration in goaf are studied by means of numerical simulation. It is concluded that the gas concentration distribution in goaf is affected by these three factors in three-dimensional numerical simulation. At the same time, considering the influence of these three factors, the gas concentration distribution in goaf is truly reflected, and the gas migration law in goaf under the condition of 30101 fully mechanized caving goaf in Shi Quan Mine is studied, and the buried depth of goaf is obtained. The functional relationship between the drainage flow rate and the gas concentration is given. From the point of view of the utilization of gas extraction and the effect of gas extraction, it is given that the best extraction position in the goaf is that the depth of the pumping mouth is in the range of 25 m. The optimal drainage flow rate of goaf buried pipe is 17.1 鈮，
本文编号：2492772
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