烟气对采空区遗煤自燃特性抑制作用研究

Research on the inhibitory effect of flue gas on the spontaneous combustion characteristics of residual coal in goaf

为研究烟气对采空区遗煤自燃的抑制作用,通过分析烟气中各组分对国家能源集团国神公司三道沟煤矿采空区遗煤在低温氧化过程中的气体释放特性及对煤炭的吸附量和竞争吸附选择性等特性参数的影响规律,探究了低温氧化过程中烟气组分抑制煤自燃特性的竞争吸附与稀释作用,揭示了烟气对煤自燃特性的抑制作用机制。结果表明,烟气可以通过关键组分CO_(2)的竞争吸附作用优先占据吸附位点,同时通过烟气的稀释作用降低环境中的O_(2)浓度,进而减少煤氧接触,抑制煤氧复合反应,减缓遗煤低温氧化进程。利用数值模拟采空区不同注入条件下氧化带的变化规律,注气后氧化带宽度变小,且向工作面推移,最终确定最佳注气位置为进风侧距工作面156m处,最佳注气流量为1 205m^(3)/h。

To study the inhibitory effect of flue gas on the spontaneous combustion of residual coal in goaf,the influences of various components in flue gas on the gas release characteristics of residual coal in the low-temperature oxidation process of Sandaogou goaf,and the adsorption capacity and competitive adsorption selectivity of coal were analyzed,on the basis,the competitive adsorption and dilution effects of flue gas components on the inhibition of coal spontaneous combustion characteristics during low-temperature oxidation were explored,revealing the inhibitory effect mechanism of flue gas on the coal spontaneous combustion characteristics.The results indicated that flue gas could preferentially occupy adsorption sites through the competitive adsorption effect of key component CO_(2),while reducing the concentration of O_(2) in the environment through the dilution effect of flue gas,thereby reducing coal oxygen contact,inhibiting coal oxygen composite reactions,and slowing down the low-temperature oxidation process of residual coal.By numerical simulation,the changes of oxidation zone under different injection conditions in the goaf was studied,which showed that the width of the oxidation zone decreased after gas injection and moved towards the working face,and the optimal gas injection position was finally determined to be 156 m away from the working face on the inlet side,and the optimal gas injection flow rate was 1205 m^(3)/h.