新一代高效低排放增压缸内直喷汽油机开发

Development of New Generation Turbocharged DI Gasoline Engine

为满足第四阶段油耗法规和国6b排放限制要求,以汽油机燃烧控制系统(GCCS)高效燃烧控制技术为核心,开发了全新一代采用米勒燃烧循环的1.5 L增压缸内直喷汽油机(TGDI)。基于多种先进的光学诊断技术搭建了燃烧系统可视化开发平台,通过对进气道、燃烧室结构及喷雾的优化设计,开发出了紧凑、高效、低排放的米勒燃烧循环控制原型。在此基础上结合系统性的降摩擦技术和分流冷却及低压废气再循环(EGR)技术,进一步降低了整机的油耗水平。热力学试验结果表明:该发动机万有特性最低油耗约为215 g/(kW·h),最高热效率约为39.3%,且具备不带汽油机颗粒捕集器(GPF)满足国6b排放的潜力。

The new 1.5 L TC DI engine development,which established on the GAC combustion controlling system(GCCS),was focused on the Miller cycle in order to meet the stricter legislation.The prototype-based combustion system was optimized by integrated use of advanced optical measurements and computational fluid dynamics to improve the in-cylinder flow characteristics,fuel sprays and the interaction between them.In addition,a series of advanced technique,such as friction reduction,flexible thermal management system and low pressure EGR,were used to improve the thermal efficiency.Experimental result from test bench showed that,the thermal efficiency of the engine was up to 39.3%,corresponding to the 215 g/(kW·h)minimum specific fuel consumption.The engine also had the potential to meet the CN6b without GPF.