不同倾角俯采工作面煤自燃“三带”分布规律研究

Study on Distribution Law of Spontaneous Combustion of Coal"Three Zones"in Overhead Working Face with Different Inclination Angles

为探究不同倾角对大倾角俯采工作面采空区煤自燃“三带”分布的影响,以刘庄煤矿110801工作面为例,采用FLUENT软件模拟大倾角俯采工作面的不同倾角,并依据现场束管测试结果进行综合对比分析,最终通过限制工作面最小平均推进速率,并设计防灭火方法,以保证工作面的安全工作。研究结果表明:氧化带在采空区进风巷一侧工作面后70~125 m处,在采空区回风巷一侧工作面后50~100 m处;随着俯采工作面倾角的增大,在采空区同一深度下氧气浓度变大,自燃“三带”的分布范围整体向采空区深部移动,且氧化带宽度逐渐增加;限制的110801工作面最小平均推进速度vmin=0.87 m/d;建议采用埋管注氮与注稠化浆体相结合的综合防灭火措施。因此,大倾角俯采工作面回采期间煤自燃“三带”分布的确定,为大倾角俯采工作面采空区遗煤自燃灾害的监测及防控提供指导。

In order to explore the influence of different dip angles on the"three zones"distribution of coal spontaneous combustion in goaf of large dip mining face,taking 110801 working face of Liuzhuang coal mine as an example,the different dip angles of large dip mining face were simulated by FLUENT software,and the comprehensive comparative analysis was made according to the field beam tube test results.Finally,the minimum average advancing rate of the working face was limited,and fire prevention and extinguishing methods were designed to ensure the safe work of the working face.The results show that the oxidation zone is 70-125 m behind the working face of the goaf air inlet lane and 50-100 m behind the working face of the goaf air return lane.With the increase of dip angle of caving face,the oxygen concentration increases at the same depth of goaf,the distribution range of spontaneous combustion"three zones"moves to the deep part of goaf as a whole,and the width of oxidation zone gradually increases;the limited minimum average advancing speed of 110801 working face vmin=0.87 m/d;it is suggested that the comprehensive fire prevention and extinguishing measures should be combined with nitrogen injection into buried pipes and thickening slurry injection.Therefore,the determination of the distribution of"three zones"of coal spontaneous combustion during the mining of large dip mining face provides guidance for the monitoring and prevention of spontaneous combustion disasters of residual coal in goaf of large dip mining face.