【摘要】 进行了在柴油可控预混压燃燃烧模式下,油嘴喷射锥角对燃烧与排放的影响研究.实验结果表明,采用155°和125°喷射锥角的油嘴,改变多脉冲喷射定时可控制预混燃烧放热幅度,影响NOx与HC和CO排放的折衷关系.在3次和6次多脉冲喷射条件下,采用125°油嘴能获得更低的NOx和HC排放.特别是采用6次脉冲喷射模式,即使在较早的喷射定时(130°CA BTDC)下,仍能保证较低的HC和CO排放.研究表明,通过减小油嘴喷射锥角、增加脉冲喷射次数和大幅度提前喷射定时,能够在获得低NOx排放的可控预混燃烧过程的同时,保证HC和CO排放只有小幅增加.更多还原

【Abstract】 Controlled premixed charge compression ignition of diesel engine based on multi-pulse injection was developed.In diesel premixed combustion mode,the effects of nozzle cone angle on emissions were studied.For each cone angle with advancing of the multi-pulse injection timing,NO_x emission is reduced,while HC and CO emissions increase.The cone angle of 125° is better for reducing the tendency of spray impinging on the cylinder wall,and for improving the utilization of air in cylinder axial direction.NO_x and HC emissions are decreased with the small cone angle for all of the multi-pulse injection timings,and CO and smoke emissions for cone angle of 125° are less than those of cone angle of 155° at large advanced multi-pulse injection timing.The experimental results indicate that reducing nozzle cone angle,increasing injection pulse number,and advancing the injection timing are the effective ways for achieving low NO_x emission and maintaining the level of HC and CO emissions.更多还原