惰气技术在防治尾巷局部火灾中的应用

在惰气防灭火技术中,N2和CO2在煤矿防灭火领域被广泛应用。基于内蒙古某矿现场先注N2、后注液态CO2的尾巷局部火灾治理措施,对采取联合惰气防灭火技术后发火区域内气体浓度的变化情况进行分析,对比N2和液态CO2对尾巷局部火灾的防灭火性能。结果表明:向发火区域内注入大量N2可有效稀释O2浓度,但在此次煤火防治中没有排除复燃隐患;由液态转化为气态的低温CO2通过稀释O2浓度和更有效地减小外部漏风,将发火区域氧浓度快速降低至3%;CO2比N2具有更好的扩散性和稀释作用,对O2、C2H4和C2H6的稀释效果较为明显,从侧面体现出CO2能更好地降低煤的氧化反应活性。经实践证明液态CO2对局部煤火的防治效果优于N2。

Application of Inert Gas Technology in Prevention and Control of Local Fire in Tail Lane

In inert gas fire prevention and extinguishing technologies,N2 and CO2 are widely used in the field of coal mine fire prevention and extinguishing.This paper based on the local fire control measures in tail roadway of a mine in Inner Mongolia with N2 injection first and liquid CO2 injection later,analyzed the change of gas concentration in the fire area after adopting the combined inert gas fire prevention and extinguishing technology,and compared the fire prevention and extinguishing performance of N2 and liquid CO2 to the local fire in tail roadway.The conclusions are as follows:large amounts of N2 injection into the combustion zone can effectively dilute the concentration of O2,but the hidden danger of re-burning has not been eliminated in this coal fire prevention and control;low temperature CO2 from liquid to gaseous reduces the oxygen concentration rapidly to 3% by diluting the oxygen concentration and reducing the external air leakage more effectively;compared with N2,CO2 has better diffusivity and dilution effect.The dilution effect of CO2,C2H4 and C2H6 is more obvious,which shows that CO2 can better reduce coal oxidation reactivity.Practice has proved that liquid CO2 is superior to N2 in preventing local coal fires.