摘要
研究了中高负荷时不同轨压和喷油提前角下,废气再循环(exhaust gas recirculation,EGR)对电控共轨二甲醚发动机排放的影响。研究结果表明:中等负荷时,随着EGR率的增大,发动机油耗率呈先减小后增大的趋势,氮氧化物(NOx)排放显著降低;对于HC和CO排放,在EGR率小于27%时基本保持不变,在EGR率增至27%时显著增加;采用27%左右EGR率,可将NOx排放降至0.5g/(kW·h)以内,此时轨压及提前角对NOx排放的影响消失。高负荷时,随着EGR率增大,发动机油耗率逐渐增大;NOx排放显著降低,轨压和提前角的变化对NOx排放影响减小;HC和CO排放逐渐增大。可通过轨压及喷油提前角的优选有效地控制中高负荷下NOx、HC、CO排放及油耗率。
The effect of EGR on the emissions of an electronically controlled common rail dimethyl ether engine was studied at different rail pressures and injection timings when the engine running at medium and heavy loads. The results show that at medium engine load, with the increase of EGR rate, the fuel consumption decreases first and then increases, and the emission of NOx decreases significantly, while the emissions of HC and CO remain unchanged when the EGR rate is less than 27%. When the EGR rate reaches about 27%, the emissions of HC and CO increase significantly, and the emission of NOx decreases to within 0.5 g/（kW·h）, while the effect of rail pressure and injection advance angle on the emission of NOx disappears. At high engine load, with the increase of EGR rate, the fuel consumption increases, the emission of NOx decreases significantly, the effect of rail pressure and injection advance angle on the emission of NOx weakens, and the emissions of HC and CO increase. Adopting appropriate rail pressure and injection advance angle can efficiently control the emissions of NOx, HC and CO, and fuel consumption.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2016年第5期39-44,共6页
Chinese Internal Combustion Engine Engineering
基金
国家"八六三"高技术研究发展计划项目(2012AA111721)
关键词
内燃机
二甲醚
电控二甲醚发动机
废气再循环
轨压
喷油提前角
排放
IC engine
dimethyl ether
electronically controlled DME engine
exhaust gas recirculation（EGR）
rail pressure
injection advance angle
emissions
