高位巷瓦斯抽采下采空区自燃危险性数值分析及应用

针对大流量高位巷瓦斯抽采可能诱发采空区自燃问题,以南山矿18层5分段综放面为研究背景,构建采空区气体渗流分析模型。利用变渗透系数和Forchheimer方程,求解非线性流与层流并存下采空区三维氧气分布。结果表明:高位巷瓦斯抽采使工作面氧气更易沿漏风方向采空区纵深发展,氧化带总体宽度会随抽放流量的提高而增加。在进风侧氧气分布后移程度较小,而回风侧受抽放负压显著影响,出现明显氧气富集区。上下隅角封堵配合注氮,会降低抽放对氧气渗入的诱导影响。依据研究结论,利用综合防火措施消除了高位巷附近潜在的自燃危险。

Numerical Analysis of Spontaneous Combustion Danger in Goaf under High Level Methane Drainage and Related Application

Aiming at prevention of spontaneous combustion induced by large flux methane drainage in goaf,the seepage feature of goaf air was analyzed theoretically.Then the dynamic permeability combining with Forchheimer nonlinear equation was used to solve 3D oxygen distribution in goaf taking 5th section face of 18 seam in Nanshan coal mine as research background.The results demonstrate that high level drainage tunnel and tail roadway can lead oxygen from the face into the depth of goaf more easily and oxygen concentration in return side is higher than intake side,that the oxidation area width increasing with increasing drainage flux,and that plugging in up and down corners plus nitrogen injection can reduce the induced effect of methane drainage on oxygen face permeating into goaf.According to the theoretic conclusion,comprehensive fire protection measures were adopted to eliminate potential spontaneous combustion danger near the drainage tunnel.