燃烧反应几个含氮小分子非谐振效应的研究

发布时间：2018-12-27 13:13

【摘要】：海运是目前世界上主流的贸易运输方式,其主要的动力设备船舶柴油机带来了巨大的环境污染。作为船舶排放的几种主要大气污染物之一,氮氧化物的生成消除反应机理引起了人们的重视。含氮小分子(CN、NCO、NH2、NH3)是含氮燃料燃烧过程中重要的中间产物,其氧化反应在NOx生成机理中占据了至关重要的地位。因此对于这几个含氮小分子的研究有助于深入了解氮氧化物生成机理,进而对燃烧反应有更为深刻的认识。本文利用Gaussian 09软件在B3LYP/6-311++G(d,p)水平上对这几组反应的物质构型进行了优化,寻找反应通道及反应过渡态,基于QCISD(T)/CCSD(T)方法在同一基组水平上对构型单点能进行了计算,并经零点能修正后得到反应能垒值。此外,基于 RRKM(Rice-Ramsperger-Kassel-Marcus)理论,利用 YL(Yao-Lin)方法对氧化反应中的速率常数进行了计算,并对其非谐振效应进行了分析。对于双分子反应,本文研究了其在正则系综下的非谐振效应。YL的计算结果显示,双分子反应中存在着极其明显的非谐振效应。随着温度的升高,谐振与非谐振速率常数逐渐增加,其中谐振速率常数增长远远快于非谐振,二者的差距迅速增大。本文计算的几个双分子体系,2000 K时谐振与非谐振常数的差距均在几个数量级以上,非谐振效应极其明显。对于单分子反应,分别研究了其在正则与微正则系综下的速率常数。YL的计算显示温度和能量对非谐振效应影响较大。正则系综下,随着温度的升高,速率常数迅速增加,非谐振效应逐渐显现。2000 K时非谐振效应不太明显。对于微正则系综,能量对非谐振效应的影响较大,2000 K对应的能量附近非谐振效应较为明显,研究中应注意考虑温度和能量对反应非谐振效应的影响。
[Abstract]:Marine transportation is the mainstream mode of trade and transportation in the world at present. Its main power equipment, marine diesel engine, has brought huge environmental pollution. As one of the main atmospheric pollutants emitted from ships, the reaction mechanism of nitrogen oxide formation and elimination has attracted much attention. Nitrogen-containing small molecules (CN,NCO,NH2,NH3) are important intermediates in the combustion of nitrogen-containing fuels, and their oxidation plays an important role in the formation mechanism of NOx. Therefore, the study of these nitrogen-containing small molecules is helpful to understand the formation mechanism of nitrogen oxides, and then to understand the combustion reaction more deeply. In this paper, the material configuration of these reactions was optimized by Gaussian 09 software at the level of B3LYP/6-311 G (dapp), and the reaction channel and transition state were found. Based on the QCISD (T) / CCSD (T) method, the single point energy of the configuration is calculated at the same base set level, and the reaction energy barrier value is obtained by modifying the zero point energy. In addition, based on RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the rate constant in oxidation reaction was calculated by YL (Yao-Lin) method, and its non-resonance effect was analyzed. For the bimolecular reaction, the non-resonant effect under canonical ensemble is studied. The YL results show that there is a very obvious non-resonant effect in the bimolecular reaction. With the increase of temperature, the rate constant of resonance and non-resonance increases gradually, and the rate constant of resonance increases much faster than that of non-resonance, and the gap between them increases rapidly. The difference between the resonant and non-resonant constants of several bilimolecular systems calculated at 2000 K is more than several orders of magnitude, and the non-resonance effect is extremely obvious. The rate constants of monolayer reactions under both regular and microcanonical ensembles are studied respectively. The calculation of YL shows that temperature and energy have great influence on the non-resonance effect. Under regular ensemble, the rate constant increases rapidly with the increase of temperature, and the non-resonant effect appears gradually, but the non-resonance effect is not obvious at 2000 K. For microcanonical ensemble, the influence of energy on the non-resonance effect is great, and the non-resonant effect near the energy corresponding to 2000 K is obvious. The influence of temperature and energy on the non-resonance effect should be considered in the study.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.21

【参考文献】