采空区瓦斯抽采与煤自燃共生灾害特征实验研究

Experimental on Symbiotic Disaster Characteristics of Gas Drainage and Coal

针对高瓦斯易自燃矿井采空区瓦斯与煤自燃共生灾害问题,研究了瓦斯抽采与煤自燃共生灾害特征及致灾机理,采用程序升温实验的方法,分析了漏风量供氧对煤自燃氧化的影响规律,在某矿S1工作面进行了现场监测实验,得出了瓦斯抽采条件下采空区CH4体积分数、O2体积分数及温度的影响规律。研究结果表明:随着温度和漏风量的增加,CH4浓度逐渐增加,O2浓度逐渐降低,CO的出现温度为110~130℃,在温度大于300℃时解吸量呈现出指数增长趋势;随着采空区深度的增加,CH4浓度呈现出浅部增加较大深部趋于稳定的趋势,O2从20.8%逐渐减小到7.7%,温度从22.3℃逐渐升高到24.3℃;划分了瓦斯抽采采空区“三带”分布,工作面散热带宽度为85m,氧化带为85~210m,窒息带为210m以后,其中氧化带宽度增加是非瓦斯抽采采空区的2倍以上。研究成果对瓦斯与煤自燃共生灾害的防治提供理论支撑。

In order to solve the symbiotic disaster of gas drainage and coal spontaneous combustion in goaf,the characteristics and mechanism of symbiotic disaster of gas drainage and coal spontaneous combustion are studied.Adopting the method of temperature programmed experiment,the influence of air leakage and oxygen supply on coal spontaneous combustion and oxidation is analyzed.Furthermore,the influence rules of gas volume fraction,oxygen gas integral fraction and temperature in goaf under gas extraction conditions are obtained by using the field monitoring experiments of S1 working face.The results show that,with the increasing of temperature and gas flow rate,the concentration of CH 4 increases as well as the concentration of O 2 decreases gradually.The appearance temperature of CO is 110℃~130℃,and the desorption amount shows an exponential growth trend when the temperature is higher than 300℃.With the increasing of goaf depth,the concentration of CH 4 increases in shallow part and tends to be stable in deep part,the oxygen content decreases from 20.8%to 7.7%,and the temperature increases from 22.3%to 24.3%.Finally,the distribution of"three zones"in goaf is divided.The width of heat dissipation band is 85 m,the oxidation band is 85~210 m,and the asphyxiation band is 210 M.The width of oxidation band increases more than twice that of non-gas extraction goaf.It provides theoretical support for the prevention and control of symbiotic disasters of gas-coal spontaneous combustion.