适用于汽油参比燃料TRF的多环芳香烃生成机理

构造了一个包括287种组分和1569个反应的汽油参比燃料TRF(toluene reference fuel)燃烧过程中多环芳香烃(PAHs)生成机理的详细化学反应动力学模型,引入四种PAH生长路径将多环芳香烃的生成机理发展到芘A4(C20H12)水平,并通过对PAH产率的分析,指出乙炔(C2H2)、丙炔(C3H3)、乙烯基乙炔(C4H4)以及含有奇数碳原子的环戊二烯自由基(C5H5)和茚基(C9H7)等物质对PAHs生成和生长起到重要作用.该机理可以较准确计算基础燃料(PRF)和TRF火焰的着火延迟期、燃烧火焰中小分子(PAH前驱体C2H2、C3H4等)和PAHs的物质浓度.通过与实验数据的比较表明,该机理在不同温度、压力、化学计量比下具有较好的性能.由此分析,该机理对碳烟前驱物PAHs的预测性能是可靠的.

A Reaction Mechanismof Polycyclic Aromatic Hydrocarbons for Gasoline Surrogate Fuels TRF

A detailed reaction mechanism consisting of 287 species and 1569 reactions for gasoline surrogate fuels TRF (toluene reference fuels) with particular emphasis on the development of an accurate model for the formation of large polycyclic aromatic hydrocarbons (PAHs) has been researched and developed in this study. Four different types of reaction pathway for the growth of the PAHs were added to the new mechanism with the largest chemical species of this mechanism being pyrene (C₂₀H₁₂). Species, such as acetylene (C₂H₂), propargyl (C₃H₃), vinylacetylene (C₄H₄), and hydrocarbons with odd number of carbon atoms, such as cyclopentadienyl (C₅H₅) and indenyl (C₉H₇), played an important role in the formation and growth of PAH molecules, based on the analysis of PAH rate of production. This mechanism could be used to predict the ignition delay timing, mole fractions of several small important species, such as the PAH precursors C₂H₂ and C₃H₄, and mole fractions of the PAHs in the flames of the primary reference fuels (PRF) and TRF. Comparisons between the calculated and experimental results indicated the good predictability of this mechanism over a wide range of temperatures, pressures, and equivalence ratios. Results showthat this TRF mechanismcan be used to reliably predict the soot precursor PAHs.