针对急倾斜高瓦斯易自燃厚煤层综放面缓慢推进条件下采空区瓦斯事故及火灾的严重性,提出了上隅角浮抽、上顺槽铺设预埋管路采空区抽放、钻场顺层钻孔裂隙带抽放瓦斯的综合防瓦斯措施,但抽采扩大了自燃氧化带,为保证采空区抽放条件下的自然发火控制,采用注氮技术控制缓慢推进工作面的采空区自燃三带范围,通过Fluent模拟分析了工作面风量对采空区火与瓦斯的影响,瓦斯抽放对采空区流场及自燃"三带"分布的影响及注氮效果。结果表明,供风量增大到一定程度,自燃氧化带最大宽度及瓦斯浓度超90%边界距工作面最大距离都会趋于平缓,该拐点为防火防瓦斯的最佳风量,Fluent模拟分析了采取防火防瓦斯措施后流场,验证了综合抽放配合注氮技术解决采空区瓦斯积聚及自然发火危险的有效性。
In order to reduce the risks of gas accident and fire in gob at steep inclined,high gas-containing,and easy spontaneous combustion coal seam at the condition of slow advance speed,the comprehensive measures were taken including floating pumping at upper corner angle,pumping by pipeline pre-buried in the gob near upper gateway and gas drainage with boreholes along coal seam. However,the range of oxidation zone increased. So nitrogen injection technology was adopted for controlling the extent of three zones in the gob. Some works were done by Fluent as follows:( 1) the influence on fire and gas in goaf by air volume;( 2) the influence on flow field and three zones in the gob due to pumping;( 3) the injection technology effect. The results showed that when air volume increases to a certain level,the maximum width of oxidation zone and the maximum distance from the face where gas concentration is over 90% will both tend to be steady,and the air volume is the best for control gas and fire. The flow field in goaf after applying the measures was analyzed by Fluent,and the measures by comprehensive gas drain-age and nitrogen injection technology were verified for gas accumulation and spontaneous combustion in the gob.