【作者】 张丽萍；

【Author】 Zhang Liping~(1,2) (1.College of Science,China University of Mining and Technology,Jiangsu,Xuzhou,221008,P.R.China; 2.School of Mechanics & Civil Engineer China University of Mining and Technology, Jiangsu,Xuzhou,221008,P.R.China)

【机构】 中国矿业大学力建学院； 中国矿业大学理学院；

【摘要】 煤中煤层气大多以吸附的形式存在,大量试验表明吸附导致了煤体体积的膨胀,解吸时体积会减小。首先在考虑到煤体吸附变形的基础上给出动态渗透率方程,然后根据多孔介质弹性力学原理并考虑到吸附应变建立煤层气运移过程中煤体变形的控制方程;根据气体的质量平衡方程,气体流动的Darcy定律,以及包含气体吸附和温度效应的孔隙率与渗透率模型建立煤层气在煤体中渗流扩散的控制方程;根据多孔介质热弹力学建立煤体温度变化的热传导控制方程,从而得到煤层气流固热耦合控制方程。最后,利用COMSOL Multiphysics软件对煤层气流固热耦合控制方程进行数值模拟计算,并与未考虑吸附变形的流固热耦合模型的模拟结果进行比较分析。研究表明,吸附变形会影响煤层气孔隙压力与渗透率规律,因此在研究煤层气流固热耦合中应考虑煤吸附变形效应。更多还原

【Abstract】 Most of the coalbed methane(CBM ) are in the form of adsorption.Adsorption resulted in the expansion of the volume of coal and desorption will shrink in some experiments.First,the dynamic permeability equation is given taking into account adsorption and volumetric thermal dilation,then the coal deformation model considering thermodynamics effect has been developed on the basis of effective stress in poroelasctic medium,in which the gas flow is include.Gas flow model is obtained according to the gas mass balance equations and Darcy’s law of gas flow.Thermal equation is established by thermoporoelasticity mechanics.Finally,coupled hydro-mechanical-thermo coupled equations of numerical simulation by COMSOL Multiphysics,and were compared with no adsorption.The results show that the adsorption will affect the pore pressure and permeability of gas fluid and different from no adsorption.Since we study on moving of gas adsorption induced deformation should be considered.更多还原