作　　者： ; ; ; ; ;

机构地区： 长安大学汽车学院

出　　处： 《西安交通大学学报》 2014年第5期32-36,77,共6页

摘　　要： 为了研究当量比对二甲醚(DME)氧化分解过程的影响,利用同步辐射真空紫外光电离及分子束取样质谱技术,并结合CHEMKIN化学反应动力学模拟软件对不同燃料氧气当量比下的低压预混层流DME/O2/Ar火焰进行了实验和数值模拟研究。测量和计算了不同当量比DME火焰中主要物种及主要中间物种的摩尔分数空间分布曲线,分析了当量比对DME火焰结构及燃料的氧化分解路径的影响。结果表明:甲醛和甲基是DME燃烧过程中最主要的中间物种;火焰中DME主要通过脱氢反应消耗,使DME产生脱氢反应的原子和原子团主要有H、OH、CH3和O,当量比不同则各基团在DME脱氢反应中的影响也不相同;DME的脱氢产物甲氧基甲基极不稳定,在火焰中一经生成就马上被消耗,其主要通过裂解反应消耗,在氧气过量的情况下,一小部分甲氧基甲基会发生加氧反应而被暂存起来。 Low pressure premixed laminar dimethyl ether/oxygen/argon flames under different equivalence ratios were investigated experimentally and numerically to study the influence of equivalence ratio on dimethyl ether combustion. The mole fraction profiles of main species and major intermediates were measured by molecular-beam mass spectrometry combined with synchrotron radiation photoionization technology and calculated by PREMIX CODE according to the typically chemical reaction model of dimethyl ether. The influences of equivalence ratio on flame structure and reaction path of dimethyl ether were analyzed. The results show that formaldehyde and methyl are the main intermediates in dimethyl ether flames, and dimethyl ether is mainly consumed by dehydrogenation reactions by H, OH, CH3 and O. The influences of radicals on dehydrogenation reactions vary with the changed equivalence ratios. Methoxy methyl produced by the dehydrogenation reaction of dimethyl ether is extremely unstable and will be consumed as soon as produced. Methoxy methyl is mainly consumed by β-decomposition reaction, or a bit reacts with oxygen under oxygen excessive condition.

关 键 词： 同步辐射 层流预混火焰 二甲醚 数值模拟

领　　域： [动力工程及工程热物理]