N_(2)对甲烷-空气预混气体爆炸火焰传播稳定性的影响  

Influence of N_(2)on the flame stability of methane-air premixed gas

作　　者：王金贵 何伟杰 张成名 张苏 WANG Jingui;HE Weijie;ZHANG Chengming;ZHANG Su(College of Environment and Safety Engineering,Fuzhou University,Fuzhou,Fujian 350108,China;Unit 32504,Shangrao,Jiangxi 334100,China)

机构地区：[1]福州大学环境与安全工程学院,福建福州350108 [2]32504部队,江西上饶334100

出　　处：《福州大学学报（自然科学版）》2023年第4期582-588,共7页Journal of Fuzhou University(Natural Science Edition)

基　　金：福建省自然科学基金面上资助项目(2020J01505)。

摘　　要：基于自主搭建的1 m^(3)球形爆炸实验系统,通过分析火焰结构与传播过程来探究不同体积分数下的甲烷和氮气对火焰不稳定性的影响及其机制.研究结果表明,甲烷-空气预混气体火焰发展过程与甲烷体积分数直接相关,当甲烷体积分数接近爆炸极限,火焰明显上浮,浮力不稳定性是火焰失稳的主要因素.当甲烷体积分数在7%~13%范围内时,火焰总体呈规则球形,在热-质扩散因素和流体力学因素相互促进或制约作用下,火焰总体不稳定性呈现先迅速增强后缓慢减弱的趋势.通过改变氮气添加比,发现流体力学不稳定性对氮气添加比的变化更为敏感,当氮气添加比(体积分数)大于8%时,在流体力学不稳定性因素的主导影响下火焰稳定性迅速增强.Based on the self-developed 1 m^(3)spherical explosion experimental system,investigating the effect of methane and nitrogen on flame instability at different volume fractions and their mechanisms by analyzing flame structure and propagation processes.The results show that the flame development process of methane-air premixed gas is directly related to the volume fraction of methane,and when the volume fraction of methane is close to the explosion limit,the flame obviously floats upward and buoyancy instability is the main factor of flame destabilization.When the volume fraction of methane is in the range from 7%to 13%,the flame has a regular spherical shape in general,and the overall instability of the flame shows a trend of rapid enhancement and then slow weakening under the effect of heat-mass diffusion factors and hydrodynamic factors promoting or constraining each other.By changing the volume fraction of nitrogen,it was found that the hydrodynamic instability was more sensitive to the change of volume fraction of nitrogen,and when the volume fraction of nitrogen was greater than 8%,the flame stability was enhanced rapidly under the dominant influence of hydrodynamic instability factors.

关 键 词：甲烷爆炸 惰化 马克斯坦长度 火焰不稳定性 

分 类 号：X932[环境科学与工程—安全科学]