预燃室催化燃烧对HCCI发动机燃烧特性的影响

对预燃室壁涂有催化剂的均质压燃(HCCI)发动机的燃烧过程进行了数值计算,分析了催化燃烧对HCCI发动机燃烧特性的影响;同时分析了预燃室内催化剂种类、过量空气系数、进气温度、进气速度、缸径以及预燃室壁温对HCCI发动机燃烧特性的影响。结果表明,预燃室存在催化燃烧时对HCCI发动机的着火时刻有很大的影响:随着过量空气系数及预燃室进气速度的增加,HCCI发动机的着火时刻提前;催化剂种类、预燃室缸径以及预燃室壁温对HCCI发动机着火时刻影响不显著,但对缸内燃烧温度影响显著。

Effects of Catalytic Combustion in Pre-chamber on Combustion Characteristic of HCCI Engine

The combustion process of the homogeneous charge compression ignition(HCCI) engine whose pre-chamber wall was coated with catalyst was simulated.The influences of catalytic combustion on the combustion characteristics of HCCI engine were analyzed.At the same time,the effects of the catalyst kinds,the excessive air coefficient,the inlet temperature,the inlet velocity,the cylinder diameter and the wall temperature on the characteristics of combustion were discussed.The results show that catalyst coated on the pre-chamber has great influence on the ignition timing of HCCI engine.With the increase of excessive air coefficient and air inlet velocity,the ignition timing is advanced.The effects of the catalyst kinds,the pre-chamber cylinder diameter and the pre-chamber wall temperature on the ignition timing of HCCI engine are not obvious,but their effects on the combustion temperature are very notable.