高温源和封闭对采空区瓦斯运移规律的影响

Effect of High Temperature Source and Sealing on Gas Migration in Goaf

为了得到采空区瓦斯运移规律,以小型采空区气体运移规律实验台为研究对象,利用计算流体力学软件Ansys-fluent对综放面采空区瓦斯运移规律进行了数值模拟,研究采空区在采用"U"型通风方式下,通风量、高温源和封闭分别对采空区的瓦斯浓度分布的影响。结果表明:通风量适当的增大能明显的降低采空区浅部的瓦斯浓度;采空区出现高温源后,随着温度升高,采空区底部瓦斯受热加剧,升浮作用明显,使得瓦斯向采空区上部积聚;采空区进行封闭措施后,采空区浅部瓦斯浓度上升较快,在各个方向上的浓度梯度逐渐消失,整个采空区瓦斯浓度不断上升并最终趋于平衡。

In order to obtain the gas migration laws in the goaf,taking the experimental platform for gas migration in small goaf as the research object,then using computational fluid dynamics software Ansys-fluent,the numerical simulation of gas migration at fully mechanized caving face was carried out; the study is about when U-type ventilation is used in the goaf,the influence of ventilation quantity,high temperature source and sealing respectively on the gas concentration distribution in goaf. The results show that the increase of ventilation rate can obviously reduce the gas concentration in the shallow part of the mined out area; when there is a high temperature in the goaf,with the increasing of temperature,the bottom gas is heated,and the rise of the gas is obvious,which makes the gas accumulation in the upper part of the goaf,after sealing,the shallow gas concentration increased rapidly in the goaf,and the concentration gradient in each direction gradually disappeared,the gas concentration in the whole goaf increased gradually and finally tended to balance.