元堡煤矿易自燃煤层初采期采空区流场数值模拟

Numerical simulation on flow field of goaf in easily combustion seam of Yuan Bao coal mine during initial caving period

易自燃煤层初采期采空区遗煤自然发火危险性很大,为了采取有针对性的防火措施需要对采空区气体流场规律研究。采取注氮气措施防火会对采空区其它气体成分形成干扰,给直接研究带来影响。利用Fluent软件数值模拟可以间接研究采空区气体流场规律。首先在模拟注氮气情况下,确定采空区煤岩平均粒径和孔隙率等多孔介质参数(由于无法直接测定,只能通过反复修改多孔介质参数使采空区气体成分与所测定值相近确定)。然后在确定的多孔介质参数下模拟非注氮气情况下采空区各气体流场。通过模拟结果研究了元堡煤矿初采期采空区各气体流场分布规律,划分出了自燃"三带"范围。

The fire danger of easily combustion seam is heavy. To effective prevent fire, the study on gas field in goal is necessary. Preventing fire by nitrogen injection has influence on study due to the interfering with other gases in air, while the study can be done by the numerical simulation software Fluent. Firstly with pouring nitrogen into the goaf, the porous media parameters were obtained, such as the average diameter of coal and rock and porosity （because it was impossible to directly test the parameters, the values were determined by changing them to make sure that the simulating gas ration is similar to the reality indirectly）. Then using the gotten porous parameters, the flow field in goaf with the nitrogen poured was simulated. The flow fields in the goal of Yuan Bao Coal Mine during initial caving period were researched and the ranges of self-ignition three belts were divided.