O2／CO2气氛下着火延迟特性影响因素分析

采用详细化学反应动力学方法研究了3种烷烃燃料（正戊烷、正己烷和正庚烷）在O2／CO2气氛及空气气氛下的着火延迟特性，探讨了初始温度为1000～1350K，压力为1．6～4．0MPa，过氧系数为0．7～1．3条件下，不同燃烧气氛、CO2体积分数、温度、压力、过氧系数等因素对3种烷烃燃料着火延迟的影响规律．结果表明：在相同初始O2体积分数条件下，高CO2体积分数气氛下3种烷烃燃料的着火延迟时间比空气气氛下明显延长；随着燃烧系统中初始CO2体积分数的增加，3种烷烃燃料的着火延迟时间进一步增加，O2／CO2气氛下出现着火延迟现象不仅与CO2的热物性有关，还与燃烧系统内CO2的化学反应动力学作用有关．

Analysis of influence factors on ignition delay characteristic under O2/CO2 atmosphere

Detailed chemical kinetics method was used to study the ignition delay characteristics of three hydrocarbon fuels(n-pentane,n-hexane,n-heptane) under high O2/CO2 concentration and air atmosphere.The influences of various parameters such as atmosphere,CO2 concentration,temperature,pressure,and equivalence ratio were also investigated in the temperature range of 1 000～1 350 K,in the pressure range of 1.6～4.0 MPa,and in the equivalence ratio range of 0.7～1.3.It can be concluded that at the same O2 initial concentration condition,the ignition delay time under high CO2 concentration atmosphere are markedly longer than that under ordinary air atmosphere.Increasing the initial CO2 concentration can further increase the ignition delay time,and the ignition delay phenomenon during O2/CO2 combustion not only relates to the CO2′s physical thermal effect,but also relates to the chemical kinetic effect of high CO2 concentration atmosphere.