综采工作面区域甲烷分布特征及关键监测位置研究

Study on the characteristics of methane distribution and key monitoring locations in fully mechanized mining face area

基于现阶段综采工作面甲烷浓度实时监测范围未覆盖综采“三机”所在区域,且工作面人工巡检位置难以把握的问题,在对工作面区域进行网格划分的基础上,通过改变落煤点位置及风速条件,并采用现场实测与仿真实验相结合的方法,对工作面区域甲烷扩散规律进行了研究,从而为优化工作面甲烷传感器的布置和人工巡检策略提供借鉴。首先将工作面受限空间划分为294个网格,然后使用FLUENT软件对工作面三维模型进行边界条件设置并开展仿真模拟实验,根据实验结果对甲烷在不同网格区域的扩散情况进行统计分析,并通过对比现场实测结果与实验数据验证仿真实验结果的有效性。研究结果表明:采煤作业进行至工作面中部时甲烷扩散范围最广,风速影响甲烷在不同区域的扩散范围,但落煤甲烷由于逆风流方向运输产生的扩散强度远小于沿风流方向扩散强度,且工作面区域甲烷浓度最大值位置仅与落煤点位置相关。综合不同落煤点位置和不同风速条件下的甲烷扩散规律,应重点在横-1区域与纵-2区域、纵-3区域的重合位置布置甲烷传感器或加强巡检频次。研究成果揭示了综采工作面区域甲烷扩散机理,对于确定工作面瓦斯监测的关键位置和保障作业人员的安全具有重要意义,为提高综采工作面瓦斯灾害防治能力提供了有力支持。

Given that the current real-time monitoring range of methane concentration does not cover the area where the“three machines”in fully mechanized mining face are located,and it is difficult to determine the locations for manual inspections,the methane diffusion law in the working face is studied on the basis of the grid division by changing the position of the coal mining point and the wind speed conditions,and by combining the on-site measurements with the simulation experiments,so as to provide a reference for optimizing the arrangement of methane sensors and the strategy of manual inspection in the working face.Firstly,the restricted space of the working face is divided into 294 grids,and then the software FLUENT is used to set the boundary conditions of the three-dimensional model of the working face and carry out simulation experiments,according to the experimental results of the diffusion of methane in the different grids to carry out statistical analyses,and by comparing the on-site measured results with the experimental data to verify the validity of the results of the simulation experiments.The research results indicate that methane diffusion reaches its widest range when coal mining operations are carried out in the central area of the working face.Wind speed affects the diffusion range of methane in different regions,but the diffusion intensity of coal falling methane resulting from transportation against the airflow direction is far less than that along the airflow direction.Moreover,the maximum methane concentration in the working face area is only related to the position of the coal mining point.Considering the methane diffusion patterns under different coal mining point positions and wind speed conditions,methane sensors should be primarily deployed or inspection frequencies should be increased at the overlapping locations of the horizontal-1 region and the vertical-2,vertical-3 regions.The research findings reveal the methane diffusion mechanism in the fully mechanized mining face,which is of great significance for determining the key location of gas monitoring in the working face and safeguarding the safety of the operators,and provides powerful support for improving the ability of preventing and controlling gas disasters in the working face.