高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2015年
1期
149-156
,共8页
马鹏%宋金瓯%宋崇林%吕刚%陈朝旭%杨传旺
馬鵬%宋金甌%宋崇林%呂剛%陳朝旭%楊傳旺
마붕%송금구%송숭림%려강%진조욱%양전왕
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
脫氫反應%速率常數%正庚烷/乙醇燃燒%異辛烷/乙醇燃燒%動力學模擬
탈경반응%속솔상수%정경완/을순연소%이신완/을순연소%동역학모의
H-Atom abstraction reaction%Rate constant%n-Heptane/ethanol%iso-Octane/ethanol%Kinetics simulation
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C2 H3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( C2 H3+C2 H5 OH →TS1→C2 H4+C2 H5 O和C2 H3+CH3→HCO TS4→C2 H4+CH3 CO)。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C2 H3路径上相近组分的预测精度有较大改善,而对C2 H3路径上较远的组分丙炔( C3 H4)和乙烯基乙炔( C4 H4)等影响不大。
在QCISD(T)/6-311++G(d,p)//B3LYP/6-311G(d,p)的水平下計算瞭乙醇及乙醇燃燒裂解產物與C2 H3之間的脫氫反應機理,利用正則變分過渡態理論( CVT)結閤小麯率隧道效應模型( SCT)計算400~2000 K範圍內的速率,對比OH, H及CH3等自由基相似脫氫反應速率,選擇2條具有較快反應速率的通道( C2 H3+C2 H5 OH →TS1→C2 H4+C2 H5 O和C2 H3+CH3→HCO TS4→C2 H4+CH3 CO)。將這2箇反應耦閤到正庚烷/乙醇混閤燃料及異辛烷/乙醇混閤燃料的機理中,利用CHEMKIN程序中預混火燄模型模擬混閤燃料的燃燒過程併進行路徑分析。對比相應的實驗數據髮現,改進的動力學模型對燃燒過程中C2 H3路徑上相近組分的預測精度有較大改善,而對C2 H3路徑上較遠的組分丙炔( C3 H4)和乙烯基乙炔( C4 H4)等影響不大。
재QCISD(T)/6-311++G(d,p)//B3LYP/6-311G(d,p)적수평하계산료을순급을순연소렬해산물여C2 H3지간적탈경반응궤리,이용정칙변분과도태이론( CVT)결합소곡솔수도효응모형( SCT)계산400~2000 K범위내적속솔,대비OH, H급CH3등자유기상사탈경반응속솔,선택2조구유교쾌반응속솔적통도( C2 H3+C2 H5 OH →TS1→C2 H4+C2 H5 O화C2 H3+CH3→HCO TS4→C2 H4+CH3 CO)。장저2개반응우합도정경완/을순혼합연료급이신완/을순혼합연료적궤리중,이용CHEMKIN정서중예혼화염모형모의혼합연료적연소과정병진행로경분석。대비상응적실험수거발현,개진적동역학모형대연소과정중C2 H3로경상상근조분적예측정도유교대개선,이대C2 H3로경상교원적조분병결( C3 H4)화을희기을결( C4 H4)등영향불대。
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 .