基于“三带”分析的采空区遗煤自燃气体分布规律及自燃危险研究

Study on distribution law of spontaneous combustion gas and spontaneous combustion risk of residual coal in goaf based on“three zones”analysis

采空区漏风导致遗煤自燃是煤矿最严重的灾害之一,为提高把控采空区漏风遗煤自燃的能力,本文以神东某煤矿31103工作面为研究对象,分析了工作面开采后覆岩“三带”分布特征,探究了采空区覆岩孔隙率分布规律,基于密闭漏风条件下采空区氧浓度分布数值模拟结果对自燃影响性进行研究,并结合31103工作面实际情况分析采空区自燃发火危险性。研究结果表明:当密闭漏风量在5.3 m^(3)/min时,随着密闭位置的增大,漏风源对采空区氧气分布及自燃“三带”分布的影响作用逐渐增强,漏风源形成的高氧区扩大了遗煤的自燃危险性。该研究成果可为类似漏风条件下采空区遗煤自燃的针对性防治提供理论参考。

The spontaneous combustion of residual coal caused by air leakage in goaf is one of the most serious disasters in coal mines.In order to improve the ability to control the spontaneous combustion of residual coal caused by air leakage in goaf,this paper takes 31103 working face of a mine in Shendong Coal Mine as the research object,analyzes the distribution characteristics of“three zones”of overlying strata after mining,and explores the distribution law of porosity of overlying strata in goaf.Based on the numerical simulation results of oxygen concentration distribution in goaf under closed air leakage conditions,the influence of spontaneous combustion is studied,and the risk of spontaneous combustion in goaf is analyzed in combination with the actual situation of 31103 working face.The results show that when the closed air leakage is 5.3 m^(3)/min,with the increase of the closed position,the influence of the air leakage source on the oxygen distribution in the goaf and the distribution of the“three zones”of spontaneous combustion is gradually enhanced,and the high oxygen zone formed by the air leakage source expands the spontaneous combustion risk of the residual coal.The research results can provide theoretical reference for the targeted prevention and control of spontaneous combustion of residual coal in goaf under similar air leakage conditions.