尿素抑制甲烷爆炸过程中爆炸压力与自由基变化耦合分析

Coupling analysis of explosion pressure and free radical change during methane explosion inhibited by urea

为建立抑爆过程中,尿素对甲烷宏观抑爆效果与微观抑爆机理之间的联系,利用20 L球型爆炸测试装置开展实验,测量了尿素粉体抑制甲烷爆炸过程中爆炸压力,利用光栅光谱仪采集火焰发射光谱数据;采用光谱分析和数据同步分析方法,分析该抑爆过程中爆炸压力和NO、CN、CHO、HNO、OH等关键自由基或分子的变化,得出甲烷爆炸压力发展过程与相关自由基含量之间的耦合变化关系。研究表明,加入尿素能有效地降低甲烷的爆炸压力,延长甲烷的爆炸感应期;在尿素的作用条件,NO、HNO含量的升高和CN、CHO、OH含量的降低,可以抑制甲烷爆炸;NO、CN、CHO、HNO自由基分子与甲烷爆炸升压过程有较大联系;OH自由基一直存在于甲烷爆炸的整个过程中且含量较高;对以上自由基的干预,可以在相应阶段发挥抑爆作用。

In order to establish the link between macroscopic explosion suppression effect and the mechanism of microscopic explosion suppression during the methane explosion suppression process,we used the 20 L spherical explosion test devices and grating spectrometer to collect data on the pressure and flame emission spectrum,analyzed changes of some key free radicals or molecules such as NO,CN,CHO,HNO and OH with the methods of spectrum analysis and data synchronization analysis during the suppression of methane explosion,and obtained the coupling relationship between the development of methane explosion pressure and related free radicals’content.The research suggests that adding urea can effectively reduce the explosion pressure of methane and extend the explosion induction period of methane.Under urea conditions,the contents of NO and HNO increase while those of CN,CHO and OH are reduced,which lead to the suppression of methane explosion;NO radicals are mainly produced during the stage of pressure increase.CN,CHO,and HNO radicals are mainly produced and peaked during the explosion induction period before pressure rises;OH radicals have always existed throughout the methane explosion and are high in content.The interference on the free radicals above can suppress the methane explosion in relevant reaction stages.