C2H3与C2H5OH和CH3HCO间的脱氢反应对乙醇-碳氢混合燃料燃烧过程的影响  

Effect of H-atom Abstraction Reactions Among C_2H_3,C_2H_5OH and CH_3HCO on the Combustion of Ethanol-Hydrocarbon Fuels

作　　者：马鹏[1] 宋金瓯[1] 宋崇林[1] 吕刚[1] 陈朝旭[1] 杨传旺 

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

出　　处：《高等学校化学学报》2015年第1期149-156,共8页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:51276126);国家“九七三”计划项目(批准号:2013CB228502)资助~~

摘　　要：在QCISD（T）/6-311＋＋G（d,p）//B3LYP/6-311G（d,p）的水平下计算了乙醇及乙醇燃烧裂解产物与C2H3之间的脱氢反应机理,利用正则变分过渡态理论（CVT）结合小曲率隧道效应模型（SCT）计算400-2000 K范围内的速率,对比OH,H及CH3等自由基相似脱氢反应速率,选择2条具有较快反应速率的通道（C2H3＋C2H5OH→TS1→C2H4＋C2H5O和C2H3＋CH3HCO→TS4→C2H4＋CH3CO）.将这2个反应耦合到正庚烷/乙醇混合燃料及异辛烷/乙醇混合燃料的机理中,利用CHEMKIN程序中预混火焰模型模拟混合燃料的燃烧过程并进行路径分析.对比相应的实验数据发现,改进的动力学模型对燃烧过程中C2H3路径上相近组分的预测精度有较大改善,而对C2H3路径上较远的组分丙炔（C3H4）和乙烯基乙炔（C4H4）等影响不大.The mechanism of C2 H3 new reactions on the combustion of ethanol/hydrocarbon blends was investigated at QCISD （ T ）/6-311 ＋＋G （ d, p ）//B3LYP/6-311G （ d, p ） level. The results indicated 2H-abstraction channels with fast reaction rate： C2 H3＋C2 H5 →OH TS1 →C2 H4＋C2 H5 O and C2 H3＋CH3 →HCO TS2 →C2 H4＋CH3 CO. The rate constants of these two reactions were calculated via the ca- nonical variational transition state theory（ CVT） among a temperature range of 400—2000 K and a small cur- vature tunneling correction was also considered. Path analyses about the n-heptane/ethanol and iso-octane/ethanol premixed flames were carried out with CHEMKIN. Compared with the experimental data, the predic- tion was apparently improved for the species adjacent to the reaction paths of C2 H3 , after the addition of the new reactions of C2 H3 to each mechanism. However, few influences were observed on other large species （ e. g. C3 H4 , C4 H4 ） , which are far from the pathways of C2 H3 .

关 键 词：脱氢反应 速率常数 正庚烷/乙醇燃烧 异辛烷/乙醇燃烧 动力学模拟 

分 类 号：O643[理学—物理化学]