矿井巷道冒顶瓦斯分布规律及治理方法评价

Gas Distribution Law of Roof Fall in Mine Gateway and Evaluation on Gas Treatment Method

针对巷道冒顶瓦斯积聚与可能引发的瓦斯爆炸问题,以塔山煤矿为研究对象,建立了瓦斯浓度变化物理模型,分析了不同风速下、放置导风板时的冒顶内以及周围瓦斯浓度变化情况。结果表明:在风速为1～4 m/s时,提高风速可有效降低瓦斯在冒顶的局部积聚,尤其可有效降低完全垮落冒顶(不大于特捷尔理论深度冒顶)的瓦斯积聚浓度;在低风速下瓦斯积聚于冒顶内,瓦斯浓度进入爆炸三角形范围,可能与煤自燃发生时空叠加,导致瓦斯爆炸;低风速下,放置导风板可有效排出积聚于冒顶内的瓦斯,但将导致冒顶下风侧瓦斯浓度增加。基于以上分析,确定在塔山煤矿5208工作面回风巷720 m处的冒顶采取充填作业,并对充填后的区域进行蓄热监测;在380 m处的冒顶放置竖直导风板,并对下风侧瓦斯浓度变化进行监测。

According to the gas accumulation in the roof fall of the gateway and the gas explosion problem might be occurred, took Tashan Mine as a study object, a physical model of gas content variation was established to analyze the gas content variation within the roof fall and the surrounding area under different air velocity and when an air guide plate was set up.The results showed that when the air velocity was 1-4 m/s ,the air velocity increased could effectively reduce the local gas accumulation in the roof fall and especially could effectively reduce the gas accumulated content of the fully falling roof（ not over the roof falling depth of Terjier Theory）.Under a low air velocity, the gas would be accumulated within the roof fall, when the gas content was in an explosion delta scope, would be overlaid with the space-time of the coal spontaneous combustion occurred and could cause a gas explosion disaster.Under a low air velocity,the air guided plate set could effectively discharge the gas accumulated in the roof fall,but the gas content at the downstream would increase.Based on the above analysis ,the roof fall at 700 m of the air returning gateway in No.5208 coal mining face of Tashan Mine was determined to have a backfill opera- tion.When the backfill operation completed, a thermal storage monitoring and measuring was conducted on the area.An air guided plate was vertically set in the roof fall at 380 m of the gateway and the monitoring and measuring was conducted on the variation of gas content in the downstream air.