高等学校化学学报

高等学校化学学报 ›› 2013, Vol. 34 ›› Issue (7): 1714.doi: 10.7503/cjcu20121047

• 物理化学 • 上一篇    下一篇

庚酸甲酯高温燃烧化学动力学机理的系统简化和分析

李树豪1, 方亚梅2, 王繁2, 李萍1, 李象远3   

  1. 1. 四川大学原子与分子物理研究所, 成都 610065;
    2. 四川大学化学学院, 成都 610064;
    3. 四川大学化学工程学院, 成都 610065
  • 收稿日期:2012-11-17 出版日期:2013-07-10 发布日期:2013-06-21
  • 通讯作者: 王 繁, 男, 博士, 教授, 博士生导师, 主要从事量子化学和理论化学计算方法研究. E-mail: wangf@scu.edu.cn E-mail:wangf@scu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 91016002, 91116001/A0204)资助.

Systematic Reduction and Analysis of Kinetic Mechanism for High-temperature Combustion of Methyl Heptanoate

LI Shu-Hao1, FANG Ya-Mei2, WANG Fan2, LI Ping1, LI Xiang-Yuan3   

  1. 1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    2. College of Chemistry, Sichuan University, Chengdu 610064, China;
    3. College of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • Received:2012-11-17 Online:2013-07-10 Published:2013-06-21

PDF (PC)

被引次数

8

摘要：

采用详细化学反应动力学机理的系统简化方法, 对庚酸甲酯高温燃烧化学动力学机理进行了系统简化. 首先采用两步直接关系图法(Directed relation graph method, DRG)和主成分分析(Principle component analysis, PCA)方法对由1087个物种、4592步可逆反应组成的庚酸甲酯燃烧的详细机理进行框架简化, 得到了包含108个物种, 547步基元反应的框架机理. 在此框架机理基础上, 进一步采用计算奇异值摄动法(Computational singular perturbation, CSP)对框架机理进行时间尺度分析, 再选取30个准稳态物种, 采用准稳态近似(Quasi steady state approximation, QSSA)方法构建了包含78个物种、74步总包反应的全局简化机理. 模拟结果表明, 在较宽的参数范围内, 框架机理和全局简化机理均能重现庚酸甲酯高温燃烧时的点火延迟、物种浓度分布和熄火等燃烧特性. 此外, 基于框架机理阐明了庚酸甲酯高温燃烧的反应路径和对点火有重要影响的基元反应. 与详细机理相比, 框架机理保留了良好的精确性和全局性, 可以很好地反映庚酸甲酯的燃烧特性, 有助于对生物柴油的燃烧过程的理解.

关键词: 庚酸甲酯, 机理简化, 直接关系图, 主成分分析, 计算奇异值摄动法, 准稳态近似

Abstract:

The detailed chemical kinetic mechanism for high-temperature combustion of methyl heptanoate was systematically reduced via integrated mechanism reduction methods. The skeletal mechanism including 108 species and 547 elementary reactions was derived via two-step directed relation graph method(DRG) combined with the principle component analysis(PCA) method from the detailed mechanism consisting of 1087 species and 4592 elementary reactions. The skeletal mechanism was further reduced through time-scale analysis. The computational singular perturbation method(CSP) was used for the selection of quasi-steady state(QSS) species, and 30 species were chosen as good candidates for QSS species. Finally, based on the quasi-steady state approximation(QSSA) method, a reduced mechanism including 78 species and 74 global reactions was obtained. Both the skeletal mechanism and the 78 species reduced mechanism could reproduce combustion characteristics of the detailed mechanism such as the ignition delay, extinction, and distribution of species concentration over a wide range of simulation conditions. Furthermore, based on the skeletal mechanism, reaction path and elementary reactions which are important for high temperature combustion of methyl heptanoate were clarified. Compared with the detailed mechanism, the skeletal mechanism is able to provide a reliable description on high temperature combustion characteristics of methyl heptanoate, which could be helpful in understanding the combustion process of biodiesel.

Key words: Methyl heptanoate, Mechanism reduction, Directed relation graph, Principle component analysis, Computational singular perturbation method, Quasi steady state approximation

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