缸内直喷汽油机技术发展趋势分析

介绍了缸内直喷(GDI)发动机技术发展过程及现状。对比分析了GDI发动机与气门口喷射(PFI)发动机的性能特点,GDI发动机相对于成熟的PFI发动机仍具有较多优势。分析了GDI发动机技术发展面临的主要问题,可以看出,排放、燃烧稳定性等方面的问题限制了分层稀燃GDI发动机普遍应用。探讨了GDI发动机燃烧系统特点及发展趋势,阐述了过量空气系数a=1的GDI均质混合燃烧方式、分层充气或均质(a=1)充气的涡轮增压技术、优化燃烧系统扩大分层稀燃区域、实现GDI发动机的HCCI燃烧等4个GDI发动机技术发展方向。

Analysis on Development for Gasoline Direct Injection Technology

The developing process and present situation of GDI(Gasoline Direct Injection) engine were introduced.The major differences of operating performance between GDI engine and PFI(Port Fuel Injection) engine were also discussed.Comparing with the PFI engine,the GDI engine had more advantages.The main facing problems of GDI development were presented subsequently and the problems of emission and combustion stability suppressed the wide application of GDI engine.The characteristic and development of the combustion system for GDI engine were discussed for further.At last the development for four kinds of technology were given,which were homogeneous combustion mode of excess air ratio(a=1),turbocharging technology of stratified charge or homogeneous charge,extending stratified lean-burn region by improving combustion system and HCCI of GDI engine.