易自燃煤层综放工作面采空区自然发火防治数值模拟

摘要

本文针对古山矿065-2大倾角易自燃综放工作面上部有小煤窑火区和上分层火区、且自然发火期仅为15d、工作面火灾防治极其困难的问题,采用在采空区埋设束管、取样化验采空区气体成分的方法,得出采空区气体浓度场分布,划分工作面采空区的自燃＂三带＂,计算出工作面日最小推进度为2.54m。运用Comsol软件,通过对采空区氧浓度进行数值模拟,并与实测采空区氧浓度进行对比验证,结果证明基于Comsol模拟采空区氧浓度分布是可行的,为易自燃煤层综放工作面采空区自然发火防治提供了可靠的理论指导。%In Gushan coalmine,the fire areas of small coal mine and upper coal seam exist in the top of 065-2 fully-mechanized caving face with large inclination and easy self-ignition coal.Moreover,spontaneous combustion period is only 15 days,so both of them contribute to especial difficulty of fire prevention in working place.Gob gas composition is ascertained by the way of sampling tests after laying beam tubes under the gob area in this study.Then according to the distribution of gob gas concentration,spontaneous ignition ＂three bands＂ are divided and the smallest value of advancing of working face is calculated as 2.54 meters.Because of this heavy workload and long testing period,and gob ponding easily lead laying equipments to inaccurate or even damaged.In view of this,by numerical simulation,using Comsol software to simulate the distribution of oxygen concentration in goaf,verifying the simulated oxygen concentration with measured oxygen concentration in the goaf.The result turns out to be feasible for the simulatin of oxygen concentration distribution in goaf based on Comsol.It provides reliable theoretical guidance for easy self-ignition of fully mechanized coal face the goaf spontaneous combustion control in the future.