二甲醚层流预混火焰试验及数值模拟  

Experiments and numerical simulation of laminar premixed dimethyl ether flame

作　　者：陈朝阳[1,2] 杨璐[1] 李跟宝[1] 黄佐华[2] 李玉阳[3] 

机构地区：[1]长安大学汽车学院,陕西西安710064 [2]西安交通大学能源与动力工程学院,陕西西安710049 [3]中国科学技术大学国家同步辐射实验室,安徽合肥230029

出　　处：《长安大学学报（自然科学版）》2014年第4期172-178,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省自然科学基金项目(2012JQ7031);中央高校基本科研业务费专项资金项目(2014G1221013);西安市科技计划项目(CXY1115(1))

摘　　要：为了研究层流预混火焰中二甲醚的氧化分解路径,利用同步辐射真空紫外光电离及分子束取样质谱技术,测量了二甲醚浓燃火焰主要物种及主要中间物种的摩尔分数空间分布曲线。基于典型的二甲醚燃烧化学反应机理和CHEMKIN化学反应动力学模拟软件,对相同条件的一维平面火焰进行了数值模拟,结合试验及数值模拟结果对二甲醚的氧化分解路径进行了分析。研究结果表明:甲醛和甲基是二甲醚燃烧过程中最主要的C1中间物种,乙烯和乙炔是主要C2中间物种;浓燃条件下,二甲醚主要通过脱氢反应消耗,使二甲醚产生脱氢反应的最主要的原子是H,其次是OH、CH3和O;二甲醚的脱氢产物甲氧基甲基极不稳定,在火焰中一经生成马上就被消耗掉,试验中没有观测到它的存在;CH2O脱氢生成HCO,HCO脱氢生成CO,CO再被OH氧化成CO2;反应CO+OHCO2+H是火焰后期生成CO2的主要方式。Laminar premixed fuel-rich （equivalence ratio of 1. 5） dimethyl ether/oxygen/argon flames were investigated experimentally and numerically to study the reaction path of dimethyl ether in premixed larninar flames. The spatial distribution profiles of the mole fractions of main species and major intermediates were measured by use of tunable synchrotron vacuum-ultraviolet photoionization and molecular-beam mass spectrometry. Meanwhile, flames under the same con- dition were simulated numerically according to the typical chemical reaction mechanism of dimeth- yl ether, and the simulation software of CHEMKIN chemical reaction dynamics and the path of dimethyl ether oxidation and decomposition was analyzed. The results show that formaldehyde and methyl are the main C1 intermediates and ethylene and acetylene are the main C2 intermediates in dimethyl ether flames. In rich flames, dimethyl ether were mainly consumed by dehydrogena- tion reaction by H,OH,CH3 and O. Methoxy methyl, as the production of the dehydrogenation reaction of dimethyl ether, is extremely unstable and would be consumed as soon as produced. Methoxy methyl is not observed in the synchrotron radiation experiment. Dehydrogenized CH2O produces HCO, HCO is dehydrogenated into CO, and then CO was oxidized into CO2 by OH finally. The reaction of CO＋HO-＊CO2 ＋H is the main path to produce COz in the late periad of flame. 6 figs, 10 refs.

关 键 词：汽车工程 二甲醚 层流预混火焰 同步辐射 数值模拟 

分 类 号：U473[机械工程—车辆工程]