正丁醇-汽油HCCI发动机低温燃烧过程的模拟  

Simulation of Low-Temperature Combustion in a HCCI Engine Fuelled with n-Butanol-Gasoline Blends

作　　者：何邦全[1] 吴永惠[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机学报》2013年第3期222-227,共6页Transactions of Csice

基　　金：国家自然科学基金资助项目(51076113)

摘　　要：利用BOOST软件计算均质充量压缩着火(HCCI)发动机的换气过程,而在CHEMKIN软件中计算压缩、燃烧和膨胀过程,其中燃烧由建立的正丁醇-汽油化学反应动力学简化机理计算.对简化机理进行了反应路径和敏感性分析.同时,模拟研究了固定气门参数及转速下,正丁醇体积分数分别为0%、10%、30%和100%时正丁醇-汽油混合燃料HCCI发动机的着火特性.结果表明:正丁醇在低温反应阶段生成的OH促使正丁醇燃料的消耗,而正丁醇反应生成的OH促进了正丁醇-汽油混合燃料中汽油替代物正庚烷和异辛烷的低温氧化,成为正丁醇-汽油燃料着火随着正丁醇含量增加而提前的主要原因;随着残余废气中甲醛含量的增加,正丁醇-汽油HCCI发动机着火时刻提前.The gas exchange processes of a homogeneous charge compression ignition（HCCI）engine were simulated by the BOOST software,while the compression,auto-ignition and combustion processes were simulated by the CHEMKIN software.Auto-ignition and combustion processes were simulated with a reduced n-butanol-gasoline kinetic mechanism.Sensitivity and pathway analysis on the chemical reactions at low-temperature combustion were made.Ignition characteristics of the HCCI engine fuelled with nbutanol-gasoline blends were simulated at the same valve timing,lift and engine speed.Results show that,hydroxy1（OH）radicals produced from n-butanol at low temperature combustion promote the consumption of n-butanol.OH radicals also promote the oxidation of gasoline substitutes including n-heptane and iso-octane at low temperature combustion.This is the reason for the advancement of ignition of the HCCI engine with the increase of n-butanol content.With the increase of formaldehyde content in the residual gases,auto-ignition of the HCCI engine is advanced.

关 键 词：汽油机 均质充量压缩着火 正丁醇 化学反应动力学 

分 类 号：TK412.2[动力工程及工程热物理—动力机械及工程]