摘要
选取高压共轨柴油机中高负荷下常用喷油压力,在定容燃烧弹内,利用高速摄像技术和燃烧压力采集系统分别试验研究了相同喷油脉宽和相同喷油量下喷油压力对柴油着火、燃烧和炭烟生成特性的影响。结果表明,在喷油压力变化范围内（40-160 MPa）：相同喷油脉宽和相同喷油量下,试验结果具有相同的变化趋势;随喷油压力升高,火焰浮起长度增加,火焰亮度逐渐减弱;高喷油压力下,压力升高率增大,压力升高始点和最高燃烧压力出现时刻均提前,放热率更快达到峰值,且放热率峰值逐渐增大;以相同喷油量为例,当喷油压力从80 MPa升高到160 MPa时,滞燃期由1.7 ms缩短到1.4 ms,燃烧持续期由6.9 ms缩短到4.7 ms,总炭烟量大幅度减少,但滞燃期和燃烧持续期随喷油压力升高而缩短的程度以及炭烟生成量随喷油压力升高而降低的趋势均逐渐减弱。
In a constant volume combustion chamber combined with high pressure common rail system,the ignition,combustion and soot formation characteristics of diesel were studied at different injection pressures keeping injection pulse width or fuel injection volume constant. The change range of injection pressure was 40 - 160 MPa,which was commonly used in high pressure common rail diesel engine under middle and high loads. The experiments were conducted by using a high-speed photography technology and a combustion pressure acquisition system. The soot formation characteristic was studied by natural flame luminosity. Results show that,keeping injection pulse width or fuel injection volume the same,the test results have the same change trend： with the increase of injection pressure,the flame luminosity becomes weaker; the ignition region becomes larger; and the flame lift-off length becomes longer. In addition,the combustion pressure rise rate would increase. Also,the moment that pressure begins to rise and the moment that the maximum combustion pressure occurs are both advanced. At the same time,the heat release rate reaches peak more quickly and the peak value increases gradually. Keeping the volume of injected fuel unchanged,with the increase of injection pressure from 80 MPa to 160 MPa,the ignition delay is shortened from 1. 7 ms to 1. 4 ms; the combustion duration is shortened from 6. 9 ms to 4. 7 ms;and the soot formation is reduced significantly. However,such trend is weakened with the increase of the injection pressure.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第1期355-361,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51336005)
关键词
高压共轨
喷油压力
定容燃烧弹
燃烧持续期
炭烟
high pressure common rail system
injection pressure
constant volume combustion chamber
combustion duration
soot
