对置二冲程柴油机喷油规律曲线对燃烧过程影响的仿真研究

Simulation of the Effect of Fuel Injection Rate-shape on Combustion Process of an Opposed-Piston Two-Stroke Diesel Engine

针对对置二冲程柴油机喷油系统与传统柴油机的不同,研究了不同喷油规律曲线形状对发动机燃烧性能的影响,探索适合对置二冲程柴油机燃烧系统的喷油规律。利用AVL-FIRE建立了对置二冲程柴油机缸内过程仿真模型,计算得到了不同喷油规律曲线形状下发动机燃烧性能。分析计算结果表明:矩形喷油规律的滞燃期最短;矩形喷油规律和梯形喷油规律最高燃烧压力点更靠近气缸容积最小点,因此等容度高;梯形喷油规律的缸内最高燃烧压力最大,NO质量分数最高而碳烟质量分数最低。

The effect of the injection rate-shape on the combustion process of an opposed-piston two- stroke diesel engine was studied. Working process simulation mode base on the AVL-FIRE was established, combustion performance during different injection rate-shape were calculated. The results show that, ignition delay of rectangular injection rate is the shrotest. Isopycnal of rectangular and trapezoid injection rate are larger than others. Maximum pressure of the trapezoid injection rate is the largest. Also NO mass fraction of the trapezoid injection rate is the largest while the soot mass fraction is the least amoung the four injection rates.