缸内直喷汽油机多种燃烧模式的试验研究

Experimental Investigation on Multi-mode Combustion of GDI Engine

基于量产增压缸内直喷汽油机,采用可变升程机构实现多种燃烧模式,在低升程下实现了均质燃烧、分层稀燃和均质压燃。试验结果表明:在转速2 000r/min,负荷0.2MPa,0.4MPa下,均质压燃的燃烧持续期最短,放热最快;在转速2 000r/min,负荷0.2MPa下,均质压燃的燃油消耗率最低,达到337g/(kW.h),同时均质压燃的NOx排放远低于均质燃烧和分层稀燃。

Based on the batch-produced turbocharged GDI engine,the multi-mode combustion was realized with the mechanism of variable tappet.The homogenous combustion,stratified lean burn and HCCI combustion were carried out at low cam lift.The results show that,in the operating points of 2 000 r/min with 0.2 MPa and 0.4 MPa loads,the shortest combustion duration and heat release can be achieved with HCCI combustion.In the operating points of 2 000 r/min with 0.2 MPa load,the lowest BSFC of 337 g/（kW·h） can be achieved with HCCI combustion,and NOx emission is far below those of homogenous combustion and stratified lean burn.