采空垮落区的风流运动和瓦斯运移作用机理

Airflow Movement and Gas Migration Mechanism in Goaf Caving Area

通过对采空区内矸石的特性分析,研究瓦斯在采空区中的扩散规律。建立瓦斯在采空区内扩散的数学模型,描绘了回采中采空区瓦斯的运移与分布的流体动力学原理。给出增大风量后瓦斯分布的算例,由此反映出工作面风压与采空区内部瓦斯压力的动态平衡性。运用质量守恒定律和非线性渗流方程,提出基于Fick扩散定律和Brinkman方程的瓦斯扩散-通风对流运移模型,综合考虑了流体压力梯度和动能作用,比较适合采空垮落区的风流运动和瓦斯对流扩散规律。通过数值模拟并与实验结果对照,研究采煤工作面采空垮落区内瓦斯运移的作用机理。认为采空区内瓦斯扩散的数值模拟的模型是有效可行的,为扩散规律的研究提供理论依据,从而有助于煤矿瓦斯监测与安全管理。

Through analyzing the characteristics of waste rock in the coal mine, the gas diffusion law is studied. The mathematical mod- el of gas diffusion is established, and the fluid dynamics features of gas migration and distribution are described. After increasing the air volmne, the dynamic balance relationship between ventilation pressure in the heading face and the gas pressure inside the goal is re- flected. Using the conservation law of mass and nonlinear seepage equations, based on Fick diffusion law and the Brinkman equations, the gas diffusion and convection model are proposed to take into account the role of fluid pressure gradient and kinetic energy. Through the comparison of numerical simulation and experimental results, the mechanism of gas migration in goal in heading face is studied. In conclusion, the mathematical model simulating the gas diffusion in goal is considered to be effective and feasible, which can provide the theoretical basis for the gas diffusion and contribute to mine gas monitoring and safety management.