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O2/CO2气氛下高浓度CO2的存在对碳氢化合物的火焰传播特性有重要影响。基于化学动力学分析软件CHEMKIN对初始压力为105 Pa,初始温度为298 K,当量比为0.6～1.4的C1～C7直链烷烃在O2/CO2、O2/N2、O2/CO2/AR气氛下的层流火焰传播速度进行模拟计算,探讨气氛、当量比、O2浓度、CO2浓度对火焰传播速度的影响规律。结果表明,火焰传播速度随当量比的增大而先增大后减小,火焰传播速度的最大值出现在当量比1.0或1.1处;在相同O2浓度下,O2/CO2气氛下火焰传播速度要比O2/N2气氛下明显减小,表明CO2的存在对火焰传播有阻碍作用;在O2/CO2/AR气氛下,在O2浓度不变情况下,火焰传播速度随CO2浓度的增大而减小;在O2/CO2气氛下,随O2浓度的提高,火焰传播速度逐渐增大,说明提高O2浓度可改善烷烃的燃烧特性。
The presence of high concentration of CO2 in the O2 / CO2 atmosphere has an important effect on the flame propagation characteristics of hydrocarbons. Based on the chemical kinetics analysis software CHEMKIN, the C1 ~ C7 linear paraffins with the initial pressure of 105 Pa, the initial temperature of 298 K and the equivalence ratio of 0.6 ~ 1.4 were obtained under the conditions of O2 / CO2, O2 / N2 and O2 / CO2 / AR The propagation velocity of laminar flame was simulated and the influence of atmosphere, equivalence ratio, O2 concentration and CO2 concentration on flame propagation velocity was discussed. The results show that the propagation velocity of flame increases first and then decreases with the increase of equivalent ratio, and the maximum value of flame propagation velocity appears at equivalence ratio 1.0 or 1.1. Under the same O2 concentration, the propagation velocity of flame in O2 / CO2 atmosphere Which was significantly lower than that of O2 / N2, indicating that the presence of CO2 hindered the flame propagation. Under O2 / CO2 / AR atmosphere, the flame propagation velocity decreased with the increase of CO2 concentration under the same O2 concentration In O2 / CO2 atmosphere, with the increase of O2 concentration, flame propagation speed gradually increased, indicating that increasing O2 concentration can improve the combustion characteristics of alkanes.