一个新的适用于HCCI燃烧及排放研究的PRF燃料化学反应简化机理  

A New Reduced Chemical Mechanism for HCCI Combustion Investigation of Primary Reference Fuels

作　　者：黄晨[1] 吕兴才[1] 黄震[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《内燃机学报》2008年第2期97-105,共9页Transactions of Csice

基　　金：国家重点基础研究发展计划资助项目(2007CB210007);上海市自然科学基金项目(06ZR14045)

摘　　要：提出了一个适用于HCCI燃烧过程研究并能考虑重要排放物的基础燃料简化动力学机理，包含42种物质，62个反应。简化机理与激波管试验以及详细机理在理论当量比，温度范围667-1250K，不同基础燃料配比（PRF100、PRF90、PRF80、PRF60、PRF0）下对滞燃期的预测较为吻合。与快速压缩机试验对比表明，简化机理对PRF90燃料在不同当量比及不同初始温度下对滞燃期的预测较为准确。与HCCI发动机试验对比表明，简化机理在不同基础燃料配比下（PRF90、PRF75、PRF50、PRF25）对滞燃期的预测较为准确。敏感性分析表明，针对PRF75燃料HCCI燃烧情况，更多正庚烷反应影响低温着火进程，更多异辛烷反应影响高温着火进程，异辛烷的烯烃裂解反应对着火速率的影响很大。A reduced chemical mechanism for primary reference fuels was developed to investigate the HCCI combustion and emissions processes. The reduced mechanism involves 42 species covering 62 reactions and was validated against experiments under engine relevant conditions. The ignition delay predicted by the reduced mechanism was compared with shock tube experiments. Good agreement was obtained for the PRF100, PRF90, PRF80, PRF60 and PRF0 fuels over the temperature range 667-1250 K at stoichiometric conditions. The ignition delay and burning rate was validated with rapid compression machine over the equivalence ratio range 0.2-0.5 and the initial temperature range 305-341 K. The ignition delay was compared with HCCI engine experiments, and good agreement was obtained for the PRFg0, PRF75, PRFS0, PRF25 fuels. Sensitivity analysis indicates that for PRF75 fuel under HCCI condition, nheptane reactions affect ignition process of low temperature region whereas iso-octane reactions affect igni- tion process of high temperature region. The olefin decomposition reaction of iso-octane has large influence on the burn rate for both lean and rich mixtures.

关 键 词：基础燃料(PRFs) 化学动力学 简化模型 HCCI 发动机 

分 类 号：TK421.4[动力工程及工程热物理—动力机械及工程]