煤层瓦斯流动的数值模拟及在煤壁的应用

The numerical simulation of gas flow in the coal seam and its application to the coal wall

研究煤层中瓦斯流动规律对于预防瓦斯突出,改善煤层瓦斯抽放率和煤层气开发利用具有现实意义。根据基本假设,对煤层瓦斯流动规律进行了研究,运用瓦斯运动方程—达西定律(DarcyLaw)、煤层瓦斯含量方程—抛物线方程、理想气体状态方程以及气体流动的连续性方程,建立了煤层单向瓦斯流动的动力学模型,并根据边界条件和初始条件,对动力学模型进行了求解,推导出煤壁单位面积的瓦斯涌出量的计算公式,分析了瓦斯涌出量的影响因素,利用测得的数据,进行了实例计算,并用vc编制了计算机程序。

Study on the law of gas flow in coal seam has practical importance for the prevention of gas extrusion, for improving the rate of gas drawing as well as for exploiting of coal gas. According to the basic hypothesis, the principle of gas flow in the coal seam is studied in this paper. On the basis of gas migration equation-Darcy Law, coal seam gas content equation-parabola equation, ideal gas state equation and the continuity equations of the gas flow, a dynamic model of gas unilateral flow in the coal seam is set up. In accordance with the boundary condition and initial conditions, the dynamic model is solved. The formula, which can be used to calculate gas discharge quantity per unit area, is then deduced. The influencing factors of gas discharge quantity are also analyzed. By the measured data, a case study is carried out, and the program of the model is conducted by vc.