摘要
以煤层瓦斯扩散渗流同步运移理论为基础,综合考虑瓦斯抽采过程中煤体变形引起的孔隙率、渗透率变化,建立了瓦斯抽采气固耦合动态数学模型。以晋城某矿为例,结合该矿煤层赋存特征,借助Comsol multiphysics软件进行了数值模拟,模拟结果表明在瓦斯抽采过程中有效抽采半径与抽采时间符合幂函数关系;随着煤层埋藏深度增加,上覆应力增大,煤层孔隙率和渗透率降低,是导致瓦斯抽采难度增加的主要原因,为此如何能提高煤层的渗透率和孔隙率是增加瓦斯抽采率的关键;单纯增大抽采负压对提高瓦斯抽采率影响不大。该研究结论为优化瓦斯抽采工艺参数提供了理论依据。
Considering the coal mass deformation and the change of permeability and porosity in the production process of gas drainage, this paper has established the gas-solid coupling dynam- ic mathematical model of gas drainage,which is based on the synchronous migration theory of coal bed gas seepage diffusion. Taking a mine in Jincheng for example,combined with the characteristics of coal seam occurrence in the mine, and with the aid of Comsol multiphysics software, this paper has carried out numerical simulation. The simulation results show that the effective radius and drainage time of gas extraction accord with the power function relationship;with the increase of embedding depth of coal seam and overburden stress, the permeability and porosity of coalbed decrease, which raises the difficulty of gas drainage. So, to improve the coal seam permeability and porosity is more important compared with to increase gas extraction rate;Suction pressure of the drainage system has little effect on gas extraction.
出处
《太原理工大学学报》
CAS
北大核心
2015年第1期60-63,68,共5页
Journal of Taiyuan University of Technology
基金
国家科技支撑计划(2007BAK29B01)
山西省科技攻关项目(2007031120-02)
关键词
同步运移
瓦斯场
煤体变形
瓦斯抽采
数值模拟
synchronous transfer
gas field
deformation of coal
gas extraction
numerical simulation
