工作面煤壁甲烷涌出在受限空间的扩散规律研究

Study on Diffusion Law of Methane Emission from Coal Wall in Confined Space of Working Face

针对综采工作面受限空间内,监测传感器无法满足甲烷浓度监测的需要,以及工作面人工巡检位置难以明确的现状,研究了工作面煤壁甲烷涌出在受限空间的扩散规律。首先将工作面受限空间划分成均匀网格,并进一步划分为3个横向区域和4个纵向区域。然后通过对工作面煤壁甲烷涌出的特征分析,结合现场数据,建立仿真模拟实验的边界条件,对不同甲烷涌出强度和风速条件下的甲烷扩散规律进行研究。实验结果表明:随着甲烷涌出强度增大,垂直煤壁方向上,靠近煤壁位置的甲烷扩散占比减少,远离煤壁位置的甲烷扩散占比增加;平行煤壁方向上,甲烷扩散占比未发生明显变化。随着工作面风速增大,垂直煤壁方向上,靠近煤壁位置的甲烷扩散占比增加,远离煤壁位置的甲烷扩散占比减少;平行煤壁方向上,回风侧区域甲烷扩散占比向进风侧区域转移。

In response to the limitations of monitoring sensors in the confined space of a fully mechanized coal mining face in meeting the need for methane concentration monitoring,and the difficulty in specifying the measurement location of the maximum methane concentration during manual inspection,the diffusion of methane emissions from coal wall in the confined space of the working facewas studied.Firstly,the confined space of the working face was divided into uniform grids,and on this basis,the working face was divided into three horizontal regions and four vertical regions.Then,through the analysis of the characteristics of methane emissions from coal wall in the working face,combined with field data,the boundary conditions for simulation experiments were established to study the diffusion law of methane under different methane emission intensities and wind speeds.The experimental results show that as the intensity of methane emission increases,in the vertical direction of the coal wall,the proportion of methane diffusion near the coal wall decreases,while the proportion of methane diffusion away from the coal wall increases.In the parallel direction of the coal wall,the proportion of methane diffusion does not change significantly.As the wind speed increases on the working face,in the vertical direction of the coal wall,the proportion of methane diffusion near the coal wall increases,while the proportion of methane diffusion away from the coal wall decreases.In the parallel direction of the coal wall,the proportion of methane diffusion in the air return side transfers to the air inlet side.