高瓦斯矿井采空区瓦斯与煤自燃耦合规律研究

针对目前采空区瓦斯与煤自燃共同致灾数值模拟仅考虑流体影响、未考虑其他物理场影响的问题,采用Comsol-Multiphysics多场耦合数值模拟软件建立了采空区瓦斯与煤自燃耦合模型,分析工作面采场与采空区瓦斯和O2分布规律,探讨抽采量和进风量对高位抽采巷道瓦斯浓度和采空区底板O2浓度的影响,并综合确定最佳抽采量和进风量。结果表明:随着抽采量的增大,瓦斯抽采浓度先增大后减小,采空区氧化升温带宽度呈正相关增长,综合考虑瓦斯抽采效果与自然发火防治,建议高位抽采巷道最佳抽采量为90m^3/min;随着进风量的增大,高位抽采巷道瓦斯浓度和纯量先增大后减小,采空区进风侧氧化升温带宽度明显增大,最大时达到109.3m,而回风侧氧化升温带宽度变化幅度很小,综合考虑瓦斯抽采效果与自然发火防治,试验工作面最优进风量为1 500m^3/min。

Research on coupling law of gas and coal spontaneous combustion in goaf of high gas mine

In view of problem that current numerical simulation of combined hazards of gas and coal spontaneous combustion in goaf only considers fluid effects,and does not consider influence of other physical fields,multi-field coupling numerical simulation software Comsol-Multiphysics is used to establish coupling model of gas and coal spontaneous combustion in goaf.Distribution law of gas and O2 in stope of working face and goaf is analyzed,and influence of drainage volume and air intake volume on gas concentration in high-level drainage roadway and O2 concentration in floor of goaf is explored to comprehensively determine the optimal drainage volume and air intake volume.The results show that with the increase of drainage volume,gas drainage concentration increases first and then decreases,and the width of oxidation temperature rise zone in goaf has a positive correlation with growth,comprehensively considering gas drainage effect and natural ignition prevention,the optimal drainage volume 90 m^3/min is recommended for high-level drainage roadway;with the increase of air intake volume,gas concentration and scalar quantity of the high-level drainage roadway first increase and then decrease,the width of oxidation temperature rise zone on the air intake side of the goaf obviously increases,and the maximum at109.3 m,the width of oxidation temperature rise zone on the return air side has a small change,comprehensively considering gas drainage effect and natural ignition prevention,the optimal air intake volume at the test face is 1 500 m^3/min.