摘要
在壁面布置限流沿 (BUMP)后 ,撞壁射流从壁面被剥离 ,形成二次空间射流 ,可大大加快空气与流体的混合速率。基于此 ,设计了带有 BUMP的燃烧室 ,采用了可灵活控制喷油规律的 FIRCRI电控共轨式喷油系统进行了发动机实验。实验结果表明 :BU MP燃烧系统能显著降低 NOx 和碳烟排放 ,在平均有效压力为 0 .6 6 MPa(原机 5 0 %负荷 )时 ,烟度只有 0 .1BSU,NOx 为 42 0× 10 - 6;由于在缸内能够形成较均匀的混合气 ,缸内平均过量空气系数在 1.3～ 2 .0的范围内时 ,烟度一直保持在 0 .3BSU以下。实验还发现 BUMP的位置以及喷油定时对排放有重要影响。BUMP燃烧系统在降低 NOx 和碳烟排放方面显示了极大的潜力。
Diesel fuel spray always impinges with the wall of combustion chamber of a D.I. diesel engine with a small or middle bore.It was found from author's fundamental research that a thin and rich wall jet of fuel/air mixture forms on the wall with a very low mixing rate with air in the combustion chamber.However,a bump on the wall of the combustion chamber can strip the wall jet off and forms a secondary space jet with much higher mixing rate.This finding has been applied to a supercharged D.I.diesel engine which is equipped with a common rail fuel injector system named FIRCRI.By means of the BUMP combustion chamber,a so-called 'Lean Diffusion Combustion Concept' is realized.The results of engine test show that the bump combustion system can reach very clean combustion at conditions lower than BMEP of 0.66 MPa.However,either soot or NO x emissions gets worse when BMEP is higher than 0.9 MPa.Further improvement of both design of BUMP combustion chamber and injection parameters is needed.
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2002年第5期381-386,共6页
Transactions of Csice
基金
国家自然科学基金重点项目 (599361 30 )
国家重点基础研究规划项目 (2 0 0 1 CB2 0 92 0 2 )
关键词
稀扩散燃烧
BUMP燃烧室
柴油机
碳烟
氮氧化物
排放性
Lean diffusion combustion
BUMP combustion chamber
Diesel engine
Soot or NO x emissions
