喷油提前角对柴油机燃烧特性的影响

Diesel Fuel Injection Timing on Combustion Characteristics

为了研究柴油机在不同喷油提前角下的燃烧特性,采用三维流体数值分析软件AVLFIRE建立了某型柴油机燃烧计算模型。在不同喷油提前角下,对燃烧滞燃期、油气混合程度、温度、燃空当量比、放热率和压力进行分析,得出:随着喷油提前角的增大,滞燃期延长,着火时刻形成的可燃混合气增多,缸内最高燃烧压力和最高温度也随之升高同时放热规律相对更加集中,燃烧初期的放热速率和压力升高比较高。

In order to study diesel engine fuel injection timing under different combustion characteristics,three-dimensional computational fluid dynamics software AVL FIRE is use to establish a model of diesel engine combustion.An analysis of ignition delay,degree of air and fuel mixing temperature,fuel-air ratio,heat release rate and pressure is carried out with different fuel injection timing.It results in that the combustible mixture formed at ignition increase with prolonged fuel injection timing ignition,so that the maximum cylinder pressure and temperature increase,the maximum heat release rate more highly concentrates,and the heat release rate and pressure rise at initial combustion are higher.