ABSTRACT

Gas and spontaneous combustion of coal have seriously threatened the production safety and efficiency during the process of mining. Gas drainage can reduce the risk of gas while it may intensify the self-ignition of coal. In order to study the certain relationship between these two issues, the south 906 working face of Dalong Coal Mine was taken into research. The physical geometrical and mathematical model was established. Numerical investigation based on Fluent was conducted to identify the gas concentration distribution and air leakage field under four different gas drainage methods, such as high drill holes drainage (HDHE), buried pipe drainage (BPE), adjacent roadway drainage (ARE), and tail roadway drainage (TRE). The simulation results show that all these four gas drainage methods are able to control the gas concentration in the air return corner, so as not to exceed the certain limit (1%). However, these methods have also enlarged the area of spontaneous combustion zone with 1.11, 1.30, 1.61, and 2.10 times, respectively. According to the comprehensive analysis on simulation results, HDHE has the minimal influence under the same gas drainage amount. This gas drainage method was then applied in the aforementioned working face. The follow-up monitoring data proved our research results, with CO concentration in the drainage pipes always keeping lower than 0.0024% and gas concentration in the air return corner maintaining no more than 0.70%. The study provides significant references for managing the gob where exists symbiosis disaster of gas explosion and spontaneous combustion of coal.

摘要

煤炭的瓦斯和自燃严重威胁着开采过程中的生产安全和效率。瓦斯抽放可以降低瓦斯的风险，同时可能会加剧煤的自燃。为研究这两个问题之间的一定关系，以大龙煤矿906南工作面为研究对象。建立了物理几何和数学模型。基于Fluent的数值研究，确定了高钻孔排水（HDHE）、埋管排水（BPE）、邻巷排水（ARE）和尾矿井4种不同瓦斯抽采方式下的瓦斯浓度分布和漏风场。道路排水系统 (TRE)。仿真结果表明，这四种瓦斯抽采方式均能控制回风角的瓦斯浓度，使其不超过一定的限度（1%）。然而，这些方法也将自燃区的面积分别扩大了 1.11、1.30、1.61 和 2.10 倍。综合模拟结果分析，在同等瓦斯抽采量下，HDHE的影响最小。该瓦斯抽采方法随后应用于上述工作面。后续监测数据证明了我们的研究成果，排水管内CO浓度始终保持在0.0024%以下，回风角气体浓度保持在0.70%以下。