膜法富氧进气改善直喷式柴油机的起动性能

Improvement on Starting Performance of a DI Diesel Engine by Using Membrane-Based Oxygen-Enriched Intake Air

在一台四冲程直喷式柴油机上进行了富氧进气改善起动性能的试验研究.使用膜法富氧系统为柴油机供应φO2,in=23%,25%和27%的3种富氧气体,实时测量起动过程中缸内压力和烟度、NOx、HC、CO排放,并与φO2,in=21%进气(环境空气)时所测数据进行比较.结果表明:采用富氧进气能够提高柴油机的起动性能,使之更快进入怠速暖机阶段;同时显著降低烟度、HC、CO排放,但NOx排放增加.

The experiments were carried out on a four-stroke, DI diesel engine. The engine was supplied with intake air containing 21% （oxygen level of ambient air）, 23%, 25% and 27% oxygen （by volume） from a membrane-based oxygen-enrichment system, respectively. The in-cylinder pressure and time-resolved emissions data were recorded and analyzed. The test results indicate that the use of oxygen-enriched intake air considerably improved the starting performance of the DI diesel engine. The engine can achieve steady operation more quickly. The smoke, HC and CO emissions decrease evidently while NOx emissions increase with the increase of oxygen content in intake air.