摘要
考察了废气再循环(EGR)、进气温度、冷却水出水温度和转速等发动机运转参数对HCCI发动机燃烧特征和排放特性的影响。实验结果表明:随EGR率提高,各种燃料的两阶段着火时刻推迟,燃烧持续期延长;高十六烷值燃料可以容许较高的EGR率,RON75最高仅可以采用45%的EGR;EGR对高十六烷值燃料的CO和UHC影响不大,对高辛烷值燃料的CO影响明显,并随EGR率增加CO排放升高。在其它运转参数中,进气温度对HCCI燃烧影响最为显著,随进气温度提高、冷却水温度升高,HCCI燃烧的着火时刻提前、燃烧持续期缩短,高辛烷值燃料的UHC和CO显著降低。转速升高,着火延迟,燃烧持续期延长。此外,研究发现,高辛烷值燃料对HCCI发动机的运转参数更为敏感。
The influence of exhaust gas recirculation(EGR)rate,intake charge temperature,coolant out temperature,and engine speed on the HCCI engines combustion characteristics and emissions were evaluated.The experimental results indicate that the combustion phase at the first stage and second stage will be postponed,and the combustion duration will increase with the introduction of Cooled EGR.HCCI engines fueled with high cetane number fuels can be operated with a higher EGR rate,while only 45% EGR rate is observed for RON75 at 1 800 r/min.Furthermore,there is a moderate effect of EGR rate on CO and UHC emissions for HCCI engines fueled with n-heptane and RON25 while a distinct effect on CO emissions for higher octane number fuels.Moreover,the combustion phase will advance and the combustion duration will shorten with the increase of intake charge temperature and the coolant out temperature and the decrease of engine speed.The study suggests that the fuel with high octane number would be more sensitive to the operating parameters in HCCI combustion.
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2005年第2期137-146,共10页
Transactions of Csice
基金
国家重点基础研究发展规划项目(2001CB209208)
国家自然科学基金重点资助项目(50136040)。
