综采支架对采空区漏风及瓦斯分布规律的影响

On the influence of the mechanized props on the air leakage and gas distribution regularity in goaf

基于多孔介质渗流理论和多组分气体渗流-扩散方程,分别建立有、无综采支架时的采空区渗流和组分传输数学、物理模型,利用Fluent软件,模拟了有、无综采支架两种情况下工作面向采空区的漏风量以及采空区瓦斯体积分数分布规律,分析了综采支架对数值解算结果的影响。结果表明:有综采支架时工作面向采空区漏风量的解算结果明显小于无综采支架时工作面向采空区漏风量的解算结果;在采空区进风侧,有综采支架时瓦斯体积分数的解算结果与无支架时瓦斯体积分数的解算结果相比差别不明显;而在采空区回风侧,有综采支架时瓦斯体积分数的解算结果明显高于无支架时瓦斯体积分数的解算结果,且有综采支架时在采空区回风侧靠近底板处解算得到的瓦斯体积分数更高。

This paper aims to study the effects of mechanized props on the air leakage and gas distribution regularity in the numerical simulation process. For a fully mechanized working face, there is no need to consider the influence of mechanized props on the numerical simulation results in the previous simulation models, for the interface between the working face and the goal used to be regarded as a direct air leakage passage. Based on the theory of the porous seepage flow and the seepage flow-diffusion equation of the muhi-componential gas, we have established two numerical models on the condition with and without fully mechanized props between the working face and the goaf. The results of our study show that, the mechanized props have had a great effect on the calculating results in the above-said two as- pects. For instance, due to the bloeking efl^ct of the mechanized prop, the air leakage from the working face to the goaf would be sig- nificantly greater with the prop than that where there were no such props. In addition, since the gas concentration of the air flow is lower in the air-entering side, the difference of gas concentration wouldn＇t be obvious; but when there exists mechanized prop, the gas concen- tration would be much higher on the air-returning side; on the other hand, with no mechanized prop, the gas concentration would be much higher at the air-returning side near the gob floor when there exist meehanized props, but the difference of the gas concentration in the top of the gob wouldn＇ t be obvious. As a result, in order to re- flect the real situation of the air leakage from the working face to the goal and the gas distribution in it, it proves to be necessary to take the effeet of the mechanized prop on the calculating results into ac- count in the process of numerical simulation.