综放工作面抽放条件下瓦斯涌出及分布特征

Characteristics of Gas Emission and Distribution of Fully Mechanized Top-Coal Caving Face Under Gas Drainage Conditions

针对乌兰煤矿5342综放工作面的实际条件,采用立体网格状的测点布置,对该工作面瓦斯体积分数三维分布进行了测定,绘出了瓦斯分布等值线图,采用求函数极值点的方法,得出了工作面沿倾向瓦斯体积分数最低点分布曲线,提出了基于瓦斯体积分数最低点分布函数的瓦斯涌出分量比例计算方法.研究表明,该工作面瓦斯体积分数沿风流方向总体呈逐渐增加趋势,介于0.095%～0.18%之间,受瓦斯抽放点的影响,局部有起伏变化;工作面横断面瓦斯体积分数分布不均匀,受瓦斯涌出、通风和抽放的影响,靠近煤壁侧瓦斯体积分数要高于采空区侧,在距离进风口约18～76.5 m范围内为凹函数分布,大于76.5 m之后,从煤壁至采空区为单调下降函数分布.经测算,该工作面瓦斯抽放总量为20.08 m3/min,风排瓦斯量为0.26 m3/min,瓦斯涌出煤壁占66.35%,采空区占33.65%.

Based on the actual conditions of the 5342 fully mechanized caving face of Wulan Coal Mine,the 3-D distribution of gas in the face is tested by measuring points arrangement in the stereo grid.The isograms of gas distribution of the face are drawn.Gas concentration nadir distribution curve along the working face incline direction is drawn by method of seeking function minimum points.The method of calculating gas emission components ratio of the face by means of the curve is brought forward.The research shows that gas concentration shows generally an increasing tendency along the working face airflow direction,from 0.095% to 0.18%,under the effect of gas drainage points,up-and-down changing locally;gas distribution in a transect of working face is unequal,under the effect of gas emission,ventilation and drainage,the gas concentration near coal wall is larger than that near goaf,which is a concave function distribution within a distance of 18~76.5 m from the inlet of working face,after greater than 76.5m,which is a decreasing distribution from coal wall to goaf.By actual survey and calculation for the face,The total value of gas drainage is 20.08 m3/min,gas value by airflow drainage is 0.26 m3/min,the gas emission ratio of the face is 66.35% from wall,33.65% from goaf.