Journal of Propulsion Technology ›› 2014, Vol. 35 ›› Issue (3): 392-396.

• Combustion , Heat and Mass Transfer • Previous Articles     Next Articles

Measurements of Ignition Delay Time and Combustion Emission Spectra of Xylenes

  

  1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;College of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • Published:2021-08-15

二甲苯点火延迟时间和燃烧发射光谱测量

张传钊1,李 萍1,赵 岩1,张昌华1,李象远2   

  1. 四川大学 原子与分子物理研究所,四川 成都 610065;四川大学 原子与分子物理研究所,四川 成都 610065;四川大学 原子与分子物理研究所,四川 成都 610065;四川大学 原子与分子物理研究所,四川 成都 610065;四川大学 化学工程学院,四川 成都 610065
  • 作者简介:张传钊(1987—),男,硕士,研究领域为碳氢燃料燃烧的光谱诊断。 E-mail:zcz19870517@163.com 通讯作者:李 萍(1956—),女,博士,教授,博士生导师。E-mail:lpscun@163.com
  • 基金资助:
    国家自然科学基金重大研究计划项目(91016002)。

Abstract: In order to study the ignition characteristics of three xylene isomers and acquire time-histories of important OH,CH and C2radicals in the combustion reaction of xylene, ignition delay times of the three xylene isomers in air were investigated behind the reflected shock waves in a chemical shock tube with a monochromator system. The ignition conditions spanned temperature of 1224~1478K and pressure of 0.18~0.21MPa with an equivalence ratio of 1.0. Time-resolved transient emission spectra of p-xylene/air in the combustion process were also obtained by using an intensified spectroscopic detector CCD system at temperature of 1440K. Experimental results illustrate that the ignition delay time of p-xylene is most sensitive to the temperature, while those of o-xylene and m-xylene are similar. The ignition delay time of m-xylene and p-xylene are close, and the time of o-xylene is the shortest at the same experimental conditions. During the p-xylene combustion reactions, the concentrations of OH, CH and C2radicals reach their peaks once they appear, but the disappearing processes of the radicals are different. The concentration of CH radical decreases rapidly in the same trend with that of C2 radical. Moreover, CH and C2radicals exist in a short time while the duration of OH radical is much longer. 

Key words: Xylene; Radical; Ignition delay time; Transient emission spectrum; Shock tube

摘要: 为了研究二甲苯三种同分异构体的点火特性,获得该燃料燃烧反应重要自由基OH,CH和C2的变化信息,在化学激波管中利用反射激波点火,点火温度1224~1478K,点火压力0.18~0.21MPa,燃料当量比1.0,由单色仪光谱系统测得了二甲苯/空气的点火延迟时间,并用ICCD瞬态光谱探测系统测得了点火温度1440K时对二甲苯/空气燃烧的时间分辨瞬态发射光谱。实验结果表明:对二甲苯点火延时对温度的敏感程度最高,邻二甲苯和间二甲苯的点火延时对温度的敏感程度相近;在相同实验条件下,间二甲苯和对二甲苯的点火延迟时间比较接近,邻二甲苯的点火延迟时间最短。在对二甲苯燃烧反应中,OH,CH和C2自由基一旦出现很快达到其浓度峰值,但各个自由基的消失过程各不相同,CH和C2自由基存在的时间很短,且相对浓度变化趋势几乎完全一致,而OH自由基持续时间最长。 

关键词: 二甲苯;自由基;点火延迟时间;瞬态发射光谱;激波管 