某四缸乘用车柴油机燃烧系统的设计优化

Design and Optimization of Combustion System for Multi-cylinders Diesel Engine of Passenger Vehicles

介绍了长城汽车研发的一款高性能"2.0VGT"柴油发动机燃烧系统的设计优化过程,通过模拟计算发动机整个工作过程,对进排气系统和进气道形状、气流运动形式、喷油器喷雾特性、燃烧室形状进行多方案优化选型。研究不同工况下,喷油规律(次数、喷油间隔、每次喷油量、喷油时刻)、喷油器特性(喷孔数量、喷孔直径、喷油压力、喷油锥角)的喷雾特性(油滴细化程度、贯穿度)对发动机性能、排放和油耗的影响规律。并对发动机实现国Ⅴ排放要求,对所需要的喷油系统特性及燃烧室形状进行研究。

This paper presents a design and optimization of combustion system for a high performance turbocharged diesel engine of 2.0 L displacement. Through simulating the whole working processes, optimization of the air intake and exhaust system, shape of intake port, forms of air-flow, spray characteristic of injector and types of the combustion chamber were carried out. Under different loads, the effects of the injection strategies （injection times, injection timing and fuel quantity injected per cycle）, injector parameters （number of spray holes, spray hole diameter, spray cone angle and fuel injection pressure） and related spray characteristics （droplet breakup and spray penetration） on the engine performance, engine fuel consumption and engine emissions were studied. In order to meet the emissions regulation of China V, researches on the injection system and combustion chamber were conducted for the engine.