活化热氛围条件下甲醇压燃燃烧低温反应机理  

Low-Temperature Oxidation Mechanism of Methanol in Active Thermo-Atmosphere Compression Combustion

作　　者：秦静[1,2] 易林[1] 林漫群[1] 

机构地区：[1]天津大学内燃机研究所,天津300072 [2]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2012年第6期504-508,共5页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50806051)

摘　　要：利用化学反应动力学软件CHEMKIN对现有甲醇详细反应动力学机理进行研究和分析.计算结果表明,活化热氛围条件下,现有甲醇机理与缸内取样实测低温阶段甲醛体积分数变化历程存在差异.基于前期缸内取样试验数据及国外相关研究结果,对甲醇低温机理中的关键反应速率进行了修正.经验证,修正机理低温阶段甲醛体积分数历程及着火时刻与试验结果更为吻合.利用修正机理就关键物质体积分数对甲醇低温氧化过程的影响进行了模拟研究.计算结果表明,甲醛初始体积分数从0增加到2×10-6使着火始点提前了近3°CA,而从2×10-6增加到20×10-6时着火时刻提前不到1°CA,说明甲醛体积分数从"无"到"有"的变化将对甲醇低温氧化及后续着火产生明显的影响.The chemical kinetic software package CHEMKIN was used to study and analyze the popular methanol detailed kinetic mechanism. The results show that the existing methanol kinetic mechanism can hardly depict the methanol concentration change at low temperature compared with the in-cylinder sampling results in active thermo- atmosphere. The reactive rates of some key reactions at low temperature were adjusted according to the in-cylinder sampling data and foreign research results. And the results show that the formaldehyde concentration history in lowtemperature process and the ignition timing are in good agreement with the experimental results. The revised kinetic model was used to simulate methanol oxidization process in order to study the effects of key substances on lowtemperature oxidation process. The results show that when the initial formaldehyde concentration increases from 0 to 2 × 10^-6, the ignition time advances by nearly 3° CA; however, when the initial formaldehyde concentration changes from 2 × 10^-6 to 20 × 10^-6, the ignition time advances by only 1° CA. It illustrates that low-concentration formaldehyde has a significant effect on the low-temperature oxidation and ignition timing of methanol.

关 键 词：活化热氛围 甲醇 低温反应机理 甲醛 着火时刻 

分 类 号：TK412[动力工程及工程热物理—动力机械及工程]