大采高采场瓦斯治理模型分析及通风系统优化研究

Study on gas control model analysis and ventilation system optimization in large mining height mines

为解决大采高采场多巷通风系统采空区通风的安全隐患及U型通风系统的瓦斯超限问题,基于大采高采场通风系统及瓦斯抽采现状建立了其瓦斯治理模型,应用采空区瓦斯运移的抽采-渗流模型及数值模拟分析了不同通风系统下大采高采场的瓦斯运移特征,实测优化了U型通风系统下定向钻孔及穿透钻孔的布置参数,并进行了抽采验证。结果表明:大直径抽采钻孔的导向作用系统改变了大采高采场及采空区流场,并使其采空区下部形成低瓦斯区域; U型通风系统下,顶板中高位裂隙带内153 mm大直径定向钻孔与间距5 m的250 mm大直径穿透钻孔结合,大幅提高了瓦斯抽采流量,避免了瓦斯超限。

In order to solve the safety hazards of the ventilation in the gob of the multi-entry ventilation system and the gas overrun of the U-type ventilation system,based on the current situation of ventilation systems and gas drainage of the large mining height working faceitsgas control model was established.The gas migration characteristics of large mining height working face under different ventilation systemswere researched by the drainage-seepage model and numerical simulation,and the layout of directional drilling and penetrating drilling under U-shaped ventilation system were optimized and were verified by gas drainage.The results show that the guiding system of large-diameter drilling borehole changes the flow field of large mining height working face and gob,and forms a low gas concentration zone in the lower part of the gob;under U-type ventilation system,gas drainage flow will be improved greatly by using roof large diameter directional boreholes of153 mm in the middle and high fractured zone and large diameter pierced boreholes of250 mm with 5 m interval,which greatly avoids gas overrun.