高抽巷抽采瓦斯流动耦合模型及内错距离分析

Analysis on Gas Flow Coupling Model of High Drainage Roadway and Inboard Distance

为解决回风巷和上隅角瓦斯超限的问题,对高抽巷与回风巷的内错距离进行了研究。根据采场气体的流动特征,基于Navier-Stokes、Brinkman、平移-扩散方程和Fick扩散定理建立了采场瓦斯流动耦合模型,采用多物理场耦合分析软件COMSOL Multiphysics模拟无高抽巷时和高抽巷与回风巷内错距离不同时,采场瓦斯浓度及流场分布特征,并结合具体的工程实例进行了验证。结果表明:不同内错距离的高抽巷对采场瓦斯治理效果有明显的影响;采空区及工作面上部瓦斯浓度大于下部,上隅角附近平均瓦斯浓度与内错距离呈"V"型关系,当内错距离约30 m时,上隅角和采空区上部瓦斯浓度最小,瓦斯治理效果最好。数值模拟结果与现场工程应用结果基本一致,证明了模型的合理性。

In order to solve the problem of gas overrun in the return airway and the upper corner, it studied the inboard distane.e between high drainage roadway and return airway. According to the characteristics of gas flow in stope, it established gas flow coupling model based on Navier - Stokes equation, Brinkman equation, pan - diffusion equation and Fick diffusion theorem, then without high drainage roadway and with different inboard distances, it simulated the characteristics of gas concentration and flow field in stope by using multi -physics coupling analysis software COMSOL Multiphysics, which was verified by specific project examples. The results showed that high drainage roadway of different inboard distances had a significant impact to the effect of gas control in stope. The gas concentration of the top of gob and working face was greater than that of the lower, it took on ＂ V＂ type relationship between the average gas concentration near the upper corner and the inboard distance. The gas concentration in the upper corner and the upper part of the goaf was the lowest and the effect of gas control was the best when the inboard distance was about 30 m. The resuhs of numerical simulation were basically consistent with the field engineering application, which proved the rationality of the model.