受限空间内惰性气体对CH4爆炸抑制特性研究

N2和CO2是常用的惰性抑爆气体,为研究两种气体的抑爆特性,采用20L球形爆炸试验装置,分析了不同浓度配比条件下N2/CH4/空气以及CO2/CH4/空气混合气体的爆炸压力,同时采集爆炸后的气体样品,对比分析爆炸后残留气体的主要成分。结果显示:随CH4浓度从5%增加至12.5%时,完全抑制CH4爆炸需要的惰性气体最小量先增大后降低,CH4浓度在6.5%~7.5%之间时,抑爆需要的惰性气体的量最大;在同一CH4浓度条件下,抑爆需要N2的量大于CO2,并且CH4浓度在5%~6.5%时,抑爆需要两种惰性气体的量值差别最大;当CH4浓度一定时,随着加入惰性气体量的增大,爆炸最大超压逐渐降低,惰性气体浓度和爆炸超压之间基本呈线性关系;在同样条件下,相对于N2,CO2为抑爆气体时,爆炸后腔体内残留的CH4浓度较高。研究成果为惰性气体抑爆技术提供技术支撑,同时为揭示惰性气体抑爆机理有一定作用。

Study on Suppression Characteristics of Methane Explosion by Inert Gases in Confined Space

In order to study the suppression characteristics of CH4 explosion by N2 and CO2,a standard 20L spherical vessel was used as explosion experiment equipment.The explosion pressure was measured under different concentration of mixture gases of N2,CH4 and air,and CO2,CH4and air.Also,the gas products after explosion were collected and analyzed to know the main composition of residual gases.The results showed that with the increase of CH4 concentration from 5%to 12.5%,the minimum amount of gas to suppress completely explosion increased first and then reduced,and when the CH4 concentration was between 6.5%and 7.5%,the maximum amount of explosion suppression gas was required;that at the same CH4 concentration,the amount of N2 required was greater than CO2,and at the CH4 concentration of 5%~6.5%,the difference in the minimum explosion gas content of the two substances was the greatest;that when the concentration of CH4 was fixed,the maximum excess pressure of the explosion gradually decreases with the addition of inert gas,and the linear relationship between the concentration of inert gas and the excess pressure of the explosion was basically present;that under the same condition,the residual CH4 concentration in the cavity after the explosion using CO2 as inert gas was higher than that of using N2.The research results provide technical support for inert gas explosion suppression technology and play a certain role in revealing the mechanism of inert gas explosion suppression.