摘要
为研究喷油策略及废气再循环(exhaust gas recirculation,EGR)对柴油机低温燃烧特性和排放特性的影响,在一台电控高压共轨柴油机上进行了试验研究。研究结果表明:EGR率的升高提高了进气比热容,降低了缸内最高燃烧压力及缸内平均温度,延长了滞燃期,降低了NOx排放,由于进气氧浓度及碳烟氧化速率的降低,增加了碳烟排放;中小EGR率下,提高喷油压力,加速油气混合程度,可以有效降低碳烟排放;推迟燃烧重心CA50到上止点后7°之后造成燃烧效率降低,扩散燃烧持续期延长,导致碳烟排放升高。
In order to study the effect of fuel injection strategies and EGR rate on diesel engine low temperature combustion performance and emissions, experimental study was carried out on an electronically controlled common rail diesel engine. The result shows that raised EGR rate makes specific heat capacity increase, peak pressure and average temperature in cylinder decrease and ignition delay extend, which leads to lower NOx emissions; but smoke emission rises due to reduced intake oxygen density and oxidation process. At medium and small EGR rates, increasing fuel injection pressure can accelerate the mixing of fuel and air and decrease smoke emission. When the combustion phase CA50 is retarded to after 7° crank angle （ATDC）, smoke emission increases because of decreased combustion efficiency and enlarged diffusion combustion period.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2016年第5期45-49,55,共6页
Chinese Internal Combustion Engine Engineering
基金
部委重点基础研究计划项目(DEDP-1004)
北京理工大学校基金项目(20130342028)
关键词
内燃机
低温燃烧
废气再循环
燃烧相位
IC engine
low temperature combustion
exhaust gas recirculation
combustion phase
