一款2.0L自然吸气混动专用发动机关键技术研究

Research on Key Technologies of a 2.0L Naturally Aspirated Hybrid Engine

为满足油耗排放法规和市场需求,结合混合动力汽车运行特点,开发了一款2.0L自然吸气四缸混动专用发动机。通过对多项关键技术的自主研究,该发动机最高热效率达到41%,扩大了燃油经济圈,排放、NVH、性能等均处于国内外领先水平。这些关键技术包括高效燃烧系统设计开发:含深度阿特金森循环、高滚流比气道、高效燃烧室的设计,高能点火系统、高响应性VVT系统、Mid-park、高精度低排放燃油喷射系统的设计匹配;抗爆震冷却系统设计;低摩擦运动副设计开发;外部冷却EGR技术的设计匹配等。本文对以上关键技术及仿真和试验结果进行阐述。此外,建立了设计、CAE仿真、零部件试验、台架试验的开发体系,为进一步提升发动机热效率提供理论基础和技术支持。

A 2.0L 4-cylinder naturally aspirated hybrid engine has been developed to meet the market demand and increasingly stringent requirement of CAFE and emission regulations.A series of advanced technologies have been employed in the engine to achieve 41%maximum brake thermal efficiency,high levels of perfomance and emission,as well as large high efficiency region in the full map.These main technologies include:design and development of high efficiency combustion system:Atkinson cycle,high tumble combustion system,high efficiency combustion chamber,high energy ignition system,variable valve timing,Mid-park,side mount gasoline direct injection with 35MPa fuel injection system;optimized thermal management;friction reduction;exhaust gas recirculation(EGR),etc.In this paper,the design of the key technologies,CAE simulation and test results will be described.In addition,the development system of design,CAE simulation,rig test and bench test was established to provied theoretical basis and technical support for further improvemnet of engine thermal efficiency.