切顶卸压沿空留巷回采工作面Y型通风漏风规律研究

Y-shaped ventilation air leakage law of working face of gob-side entry retaining by cutting roof to release pressure

为研究切顶卸压沿空留巷下Y型通风漏风规律,以发耳矿31004工作面为工程背景,提出标定界限法测量采空区碎胀系数,推导出采空区多孔介质模型孔隙率及渗透率分布规律;结合FLUNET数值模拟软件,对不同Y型通风模式、不同风量及不同留巷长度下Y型通风风流场分布规律及漏风情况进行分析。相同配风量下,"两进一回式"Y型通风模式下的采空区"三带"范围比"一进两回式"Y型通风模式小,后者自燃带范围大。不同风量下,"两进一回式"Y型通风工作面端部10 m范围、留巷侧30~100 m范围漏风严重,且留巷侧、机巷侧"三带"范围(除窒息带外)随总配风量的增大而增大,但沿空留巷侧散热带、自燃带范围均比不留巷侧要大,其窒息带比不留巷侧更靠近采空区深部,要重点加强留巷侧"三带"范围控制。留巷长度小于等于100m时,由于采空区内部冒落矸石未压实,工作面及留巷侧漏风严重,反之,漏风量很小或基本不漏风。

In order to study the air leakage law of Y-shaped ventilation under gob-side entry retaining by cutting roof to release pressure, with working face 31004 of Fa’er Mine as engineering background,the calibration limit method was proposed to measure goaf breakage coefficient, and the distribution law of porosity and permeability of porous media model for goaf was derived. Furthermore, with FLUNET numerical simulation software, the distribution law of Y-shaped ventilation air flow field and air leakage, includng different ventilation modes, different air volumes and different roadway lengths were analyzed. The results have shown that under same air distribution, three-zone range of goaf of two-intake-and-one-return Y-ventilation mode is smaller than that in one-intake-and-two-return Y-ventilation mode. The latter has a large autoignition zone. Under different air volumes, there are serious air leakage problems at the end of two-intake-and-one-return type Y-ventilated working face of about 10 m, and serious air leakage within the range of 30~100 m from the lane side. And the range of three zones(except the suffocating zone) on the roadway side and machine lane side increases with the increase of total air distribution volume. However, the range of scattered tropical zone and spontaneous combustion zone along gob-side entry retaining side is larger than that without entry retaining side, and the suffocating zone is closer to the depth of goaf than that without entry retaining side, which means it is necessary to strengthen control of three belts on the lane side. When the length of retained lane is less than or equal to 100 m, if gangue falling in the goaf is not compacted, the working face and the side of the retained lane will leak seriously;otherwise, the amount of air leakage is small or almost zero.