反应速率对层流扩散火焰特性的影响  

Effect of Reaction Rate on the Characteristics of Laminar Diffusion Flame

作　　者：谢欣容 刘石[2] XIE Xin-rong;LIU Shi(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing,China,102206;School of Control and Computer Engineering,North China Electric Power University,Beijing,China,102206)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206 [2]华北电力大学控制与计算机工程学院,北京102206

出　　处：《热能动力工程》2022年第5期38-45,61,共9页Journal of Engineering for Thermal Energy and Power

摘　　要：为探究燃烧过程中火焰结构和烟黑特性的变化规律,对层流乙烯/空气扩散火焰进行了数值模拟,分析了不同成核过程和表面生长过程中,反应速率常数的指前因子及活化能对层流乙烯/空气扩散火焰温度和烟黑体积分数的影响。结果表明:成核反应速率常数中,指前因子增大,火焰温度降低,烟黑体积分数增大,当指前因子提高50%时,在轴向高度3 cm位置对应的火焰温度峰值减小0.70%,烟黑体积分数的峰值增大37.98%;活化能增加,火焰温度增大,烟黑体积分数减小,当活化能提高50%时,在轴向高度3 cm位置对应的火焰温度峰值增大3.41%,烟黑体积分数的峰值减小78.92%;表面生长反应速率常数中,指前因子增大,火焰温度逐渐减小,烟黑体积分数逐渐增大,当指前因子提高50%时,在轴向高度3 cm位置对应的火焰温度峰值减小2.03%,烟黑体积分数的峰值增大1.65倍;活化能增加,使火焰温度升高,烟黑体积分数减小,当活化能提高50%,在轴向高度3 cm位置对应的火焰温度峰值增大9.61%,当活化能提高12.5%,烟黑体积分数的峰值减小46.68%。To explore the variation rules of flame structure and soot characteristics during the combustion process, a laminar ethylene and air diffusion flame was numerically simulated.The effect of pre-exponential factors and activation energy of the reaction rate constants on the laminar ethylene and air diffusion flame temperature and soot volume fraction in different nucleation and surface growth processes was analyzed.The research results show that the flame temperature decreases and the soot volume fraction increases with the increase of pre-exponential factor in the nucleation reaction rate constants.When the pre-exponential factor increases by 50%, the peak of flame temperature corresponding to the axial height of 3 cm decreases by 0.70% and the peak of soot volume fraction increases by 37.98%.The flame temperature increases and the soot volume fraction decreases with the increase of activation energy.When the activation energy increases by 50%, the peak of flame temperature corresponding to the axial height of 3 cm increases by 3.41%,and the peak of soot volume fraction decreases by 78.92%.The flame temperature gradually decreases and the soot volume fraction gradually increases with the increase of pre-exponential factor in the surface growth reaction rate constants.When the pre-exponential factor increases by 50%,the peak of flame temperature corresponding to the axial height of 3 cm decreases by 2.03%,and the peak of soot volume fraction increases by 1.65 times.The flame temperature increases and the soot volume fraction decreases with the increase of activation energy.When the activation energy increases by 50%,the peak of flame temperature corresponding to the axial height of 3 cm increases by 9.61%;and when the activation energy increases by 12.5%,the peak of soot volume fraction decreases by 46.68%.

关 键 词：扩散火焰 数值模型 成核速率 表面生长速率 温度 烟黑体积分数 指前因子 活化能 

分 类 号：Q038.1[生物学]