沿空留巷工作面“一进两回”通风方式下采空区漏风规律研究

Study on air leakage law of goaf under“one inlet and two return”ventilation in gob-side entry retaining working face

为了正确判断“一进两回”通风方式下工作面采空区风流流动方向,指导矿井加强采空区瓦斯管理,以古汉山矿1604综采放顶煤工作面为研究对象,通过在工作面开切眼下部煤壁及运输巷沿空留巷外段分别释放SF_(6)气体,考察确定工作面漏风及瓦斯运移规律,并结合通风阻力变化及风量测定结果,分析采空区漏风随工作面推进的动态变化过程。研究结果表明:工作面风流分别自沿空留巷上帮及开切眼下部漏入采空区,并由开切眼上部涌入工作面,留巷初期总漏风量约占进风量的15%;沿空留巷漏风加大了采空区瓦斯涌出量及涌出范围,工作面检修期间采空区瓦斯涌出量占工作面总瓦斯涌出量的75%;沿空留巷段漏风通道随工作面推进整体呈增大趋势,但漏风量在留巷阶段初次来压前达到峰值,而后受巷道风流阻力变化影响,留巷段分风量、漏风量均呈缓慢下降趋势。

In order to correctly judge the air flow direction in goaf of the working face with “one inlet and two return” ventilation, and guide the mine to strengthen the management of gas drainage in goaf, taking 1604 fully mechanized top coal caving face of Guhanshan Coal Mine as the research object, by releasing SF_(6) gas at the lower coal wall of the open-off cut in the working face and the outer section of gob-side entry retaining, the air leakage and gas emission law of the working face were analyzed and determined. Combined with the change of ventilation resistance and the measurement results of air volume, the dynamic change process of air leakage in goaf with the advance of working face was analyzed. The results show that, the air flow of the working face leaks into the goaf from the upper side of gob-side entry retaining and the lower part of the open-off cut, and flows into the working face from the upper part of the open-off cut, and the total air leakage in the initial period of gob-side entry retaining accounts for about 15% of the air intake;the air leakage of gob-side entry retaining increases the gas emission amount and emission range of goaf, the amount of gas emission from the goaf accounts for 75% of the total gas emission during the maintenance of the working face;the air leakage channel along the gob-side entry retaining increases with the advance of the working face, but the air leakage reaches the peak before the first pressure in gob-side entry retaining, and then affected by the change of roadway air flow resistance, the sub air volume and air leakage in gob-side entry retaining show a slow downward trend.