摘要
控制直喷式柴油机高速工况的放热率,能保证柴油机最佳的排放性能和经济性能.通过降低柴油机几何压缩比,推迟着火始点,可降低柴油机的燃烧最高温度和NOx排放;通过采用双壁面射流技术,能实现快速燃烧,不至于使油耗率和烟度恶化.基于上述思想,在柴油机3 000r.min-1转速下进行了试验研究.结果表明:双壁面射流燃烧系统与原机油耗率相差不大,NOx排放得到了大大的降低,但双壁面射流燃烧系统的烟度在大负荷下有所增加.双壁面射流燃烧系统的缸压峰值与原机相比,有大幅度的降低,着火后的压力升高比也低于原机.双壁面射流燃烧系统的着火始点与原机相比,滞后2～3℃A.3 000r.min-1各负荷下,在累计放热率5%～50%阶段,双壁面射流燃烧系统几乎与原机有相同的燃烧速率,都属于快速燃烧;在累计放热率50%～90%阶段,双壁面射流燃烧系统的燃烧速率变慢.
The rate of heat release （ROHR） of DI diesel engine in high-speed operating conditions is controlled to ensure the best emissions and economy performances. The compression ratio is reduced, and the start of combustion （SOC） is retarded, which makes the peak cylinder temperature and NOx emissions reduced. The double-wall-jet technique is used to achieve the rapid combustion ensuring the brake specific fuel consumption （BSFC） and smoke not deteriorating. Based on the above ideas, the experiments are carried out for the research at speed of 3 000 r - min-1. The experimental results show that： Compared with the original engine, the BSFC of the double-wall-jet combustion system is almost same, NOx emission is greatly reduced, but smoke at heavy load is slightly increased. The peak cylinder pressure of the double-wall-jet combustion system is significantly reduced, and the pressure rise ratio is lower than that of the original engine. The SOC of double-wall-jet combustion system is retarded 2-3 ℃A. For each load at 3 000 r ·min-1 , with the cumulative heat release rate changing from 5% to 50%, the burning rate of double-wall-jet combustion system and the original one are almost the same, which belong to rapid combustion system, but with the cumulative heat release rate changing from 50% to 90%, the burning rate of double-wall-jet combustion system is lower.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2013年第2期194-199,共6页
Journal of Dalian University of Technology
关键词
双壁面射流
柴油机
燃烧
NOx
放热率
double-wall-jet
diesel engine
combustion
NOx
rate of heat release （ROHR）
作者简介
郭鹏江（1977-），男，博士生，E—mail：guopengjiang@sina．com
