小尺寸管道内二氧化碳抑制甲烷爆炸效果的实验及数值模拟

Experimental and numerical studies on the suppression of methane explosion using CO_2 in a mini vessel

为了有效防治矿井瓦斯爆炸事故,以瓦斯的主要成分甲烷作为模拟气体,运用自主设计改装的XKWB-S型小尺寸石英玻璃管道实验系统,结合高速摄影仪,并采用FLACS数值模拟软件,研究惰性气体抑爆条件下甲烷燃烧爆炸特性,进行体积分数为6%~27%的CO2抑制体积分数为9%CH4爆炸的实验及数值模拟,结果表明：各组分混合气体在爆炸传播过程中,爆炸压力、火焰锋面速度和气体运动速度均呈现一定程度的波动,且压力和速度没有同时达到最大值;CO2的加入有效抑制了甲烷/空气反应,且添加CO2体积分数越大,抑爆效果越明显,模拟结果与实验结果基本吻合。

Gas explosion is the leading accident in underground coal mining in China.In order to prevent mine gas explosion effectively,methane,the dominant sector of mine gases,was taken as experimental medium.A quartz tube test system,in which the ratio of length to diameter is 18,was designed and made.A high-speed camera and numerical simulation software FLACS was employed to study the characteristics of methane explosion.The impact of CO2 at various concentrations on the suppression of 9% methane explosion was investigated.Fluctuations were observed on the explosion pressure,the velocity of the flame front and the velocity of the mixed gases during the propagation of the gas explosion.The time to reach the maximum for the pressure was not simultaneous with that for velocity.Additionally,carbon dioxide can effectively suppress the reaction between methane and oxygen and the larger the concentration of CO2 is,the better the suppression effect will be.Simulation results are in accordance with the experiments.