回采工作面气体浓度分布统计规律

煤自燃是影响矿井安全生产的主要灾害,而指标气体是预警煤自燃最有效的参数之一。为了掌握采空区气体浓度分布特征,为煤自燃预警提供数据支撑,本文基于统计学理论研究了采空区气体的分布特征,并利用小波变换分析了采空区CO浓度变化的周期性。研究结果表明:采空区内的O_2浓度服从正态分布,CO浓度服从对数正态分布;相同盘区的采空区煤自燃"三带"分布具有相似性,且进风侧漏风带宽度大于回风侧约10m,氧化带宽度比漏风带宽20～30m;采空区CO浓度具有显著的周期性,存在第一主周期和第二主周期,且在第一主周期内,CO浓度变化符合"高-低-高"的分布特征,其分布周期与工作面周期来压时长相同。该研究结果对掌握采空区气体分布规律及煤自燃预警具有重要的工程意义。

Statistical Law of Gas Concentration Distribution in coal Mine Working Face

Spontaneous combustion of coal is a major disaster affecting the safe production of mines, and the indicator gas is one of the most effective parameters for early warning of spontaneous combustion of coal. In order to grasp the characteristics of gas concentration distribution in the air extraction zone and to give early warning of coal spontaneous combustion with data support, the statistical characteristics of O2 and CO in the air extraction zone, the distribution of coal spontaneous combustion "three zones" in different working surfaces, and the periodic distribution of CO concentration in different scales were studied, and it was found that: the O2 concentration in the high suction roadway obeys the normal distribution, and the CO concentration obeys the log-normal distribution; the distribution of coal spontaneous combustion "three zones" in the air extraction zone of the same mining sector is similar, and the width of the leakage zone on the inlet side is larger than the return side, about 10m, and the width of the oxide zone is about 20m~30m wider compared with the leakage. The CO concentration distribution has a significant "high-low-high" periodicity at scales greater than 40 time units, and the period is the same as the working surface periodic pressure time.