基于COMSOL Multiphysics的瓦斯抽采有效半径数值模拟

Research on the gas extraction effective radius by simulation based on COMSOL Multiphysics

为了准确确定煤层钻孔预抽有效半径,以便合理布置本煤层预抽钻孔,建立了钻孔周围煤体的瓦斯流动模型,并利用COMS0L Multjphysics软件求解所建模型的解析解,通过模拟解算得出相应抽采条件及预抽时间内,钻孔抽采有效半径范围,为抽采钻孔的布置提供理论依据,从而实现最优的设计、最小的工程量和最佳的抽采效果.试验结果表明:在实际的工程应用中,根据模拟得出的瓦斯压力分布图可以确定有效抽放半径随抽采时间的变化关系,该方法克服了传统方法难于封口、测试过程繁琐等缺点,能够筒便且较准确的确定抽采半径范围.为工程实际提供理论依据.

In order to accurately determine the effective coal seam drill a radius and in order to a reasonable decorate the coal seam the pumping drilling, this paper establishes the drilling of coal around the flow of gas model, and uses COMSOL Muhiphysics software solution of the analytical solution of the model. Through the simulation, we get the corresponding solution extraction conditions and the smoke time, drilling extraction effective radius, for extraction of drilling decorate to provide the theory basis, so as to achieve the optimal design, the smallest quantity and the best extraction effect. The test results show that in the practical engineering application, and on the basis of simulation, the gas pressure distribution can identify effective drainage radius with the change of time extraction relationship. This method can overcome the disadvantage of traditional approach, in which there are some shortcomings, as difficult to sealing, and trivial test process. It is simple and accurate to determine the radius of extraction, to provide a theoretical basis for the engineering practice.