柴油燃烧碳烟生成特性的计算和试验研究  

Numerical Simulation and Experiment Research of Soot Formation Characteristics in Diesel Fuel Combustion Process

作　　者：陈亮[1] 成晓北[1] 颜方沁[1] 董世军[1] 陈国华[1] 

机构地区：[1]华中科技大学能源与动力工程学院,湖北武汉430074

出　　处：《工程热物理学报》2013年第8期1565-1569,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51176056)

摘　　要：本文采用改进的详细碳烟模型,耦合了由正庚烷和甲苯组成的混合燃料的简化反应机理,以一台单缸柴油机为研究对象,对此详细碳烟模型预测柴油机碳烟生成和氧化过程的准确性和有效性进行了验证。结果表明,模拟得到的缸内压力和放热率曲线,以及着火时刻和试验结果非常吻合,得到碳烟排放量的模拟值与试验值的变化趋势基本一致,因而本文的详细碳烟模型可较好地预测不同工况条件下柴油机碳烟颗粒排放的变化趋势;同时,采用本文提出的详细碳烟模型对柴油机内碳烟颗粒数浓度和平均尺寸进行数值模拟,结果表明,随着时间的增长,碳烟颗粒的数量先增加后减小,尺寸分布范围由小变宽,然后再变小,最后其分布趋于稳定。Using an improved detailed soot model and a reduced diesel surrogate fuel chemical reaction mechanism of n-heptane/toluene, a computational validation study is performed on the veracity and effectiveness of the detailed soot model which could predict the process of soot formation and oxidation in a single-cylinder diesel engine. In this detailed soot model, the effects of soot precursors including isomers of acetylene and PAHs on soot formation are considered. The result shows that the simulated in-cylinder combustion pressure, heat release curve and ignition timing are in excellent agreement with the experimental results. The simulated changed trend of soot emissions is in consistent with the experimental results. Meanwhile, the changes of particle number concentration and average size in diesel engine simulated by using the improved detailed soot model are studied. The result shows that the particle number concentration increases firstly and then decreases, the narrow range of the particle size becomes wide in the early and then becomes narrow, and is tend to stable afterwards correspondingly with the time.

关 键 词：详细碳烟模型 单缸柴油机 数密度 平均尺寸 

分 类 号：TK428.9[动力工程及工程热物理—动力机械及工程]