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为了分析废气再循环中NO对HCCI燃烧的影响,本文构建了一个新的NO与异辛烷相互作用的化学动力学机理,包括167种组分和835个反应,其中异辛烷分支反应包括112种组分和467个反应。NO分支的子机理是在Anderlohr等人对NO与异辛烷详细机理研究的基础上根据路径分析而得到的。新IC_8H_(18)-NO机理的验证分为:IC_8H_(18)-NO分支机理验证了在激波管中温度范围为855-1269 K,压力范围为2-6 MPa,化学计量比为0.5和1.0条件下的着火延迟时间;IC_8H_(18)-NO机理验证了在HCCI发动机中NO添加浓度为0-500×10-6(体积分数),同时也发现不同的NO添加浓度对IC_8H_(18)-NO的HCCI燃烧的影响有所不同。因此,本文利用CHEMKIN PRO软件中的零维单区化学动力学模型,模拟了在不同NO浓度下NO对异辛烷燃烧影响。通过敏感性分析和产率分析,得出了NO添加后对异辛烷燃烧影响的关键性反应为R476。在IC_8H_(18)-NO燃烧初期通过R476产生活性基OH,从而体现对燃烧的促进作用。但是在NO添加浓度较大时,由于NO浓度较大结合活性基(如OH)的能力增强,进而NO对燃烧的促进作用被削弱。
In order to analyze the influence of NO on the combustion of HCCI in EGR, a new chemical kinetic mechanism of the interaction between NO and isooctane was established, including 167 components and 835 reactions. Among them, the isooctane branching reaction consisted of 112 Components and 467 reactions. The subbranch of the NO branch is derived from the path analysis by Anderlohr et al. On the basis of detailed mechanistic studies of NO and isooctane. The verification of the new IC_8H_ (18) -NO mechanism is divided into: IC_8H_ (18) -NO branching mechanism verifies that in the shock tube the temperature range is 855-1269 K, the pressure range is 2-6 MPa, the stoichiometry is 0.5 and 1.0). The mechanism of IC_8H_ (18) -NO showed that the NO concentration in the HCCI engine was 0-500 × 10-6 (volume fraction), and different concentrations of NO were also found to affect the IC_8H_ (18) The impact of HCO combustion with -NO is different. Therefore, in this paper, the zero-dimensional single-region chemical kinetics model in CHEMKIN PRO software was used to simulate the effect of NO on isooctane combustion under different NO concentrations. Through the sensitivity analysis and yield analysis, it is concluded that the key reaction of NO addition to isooctane combustion is R476. In the early stage of combustion of IC_8H_ (18) -NO, active radical OH was produced through R476, which reflected the promotion of combustion. However, when the concentration of NO is increased, the promotion effect of NO on combustion is weakened due to the enhanced ability of the NO concentration to bind the active group (such as OH).