HC and CO emissions reduction by early injection strategy in a bioethanol blended diesel-fueled engine with a narrow angle injection system

摘要

The main purpose of this study was to investigate how a narrow angle injector affects the combustion and exhaust emissions characteristics in a single-cylinder diesel engine fueled by diesel-bioethanol blends. This study focused on reducing HC and CO emissions in the exhaust emissions by the bioethanol blending of diesel. A narrow angle injector with an injection angle of 70° was used and compared with a conventional angle injector having a 156° injection angle. The bioethanol was blended with the conventional diesel up to 30% with 5% biodiesel. Experiments revealed that, in a narrow angle injector, the pre-mixed combustion duration increased with bioethanol contents unlike the similar value of conventional injector. The premixed combustion phasing decreased with the increase of bioethanol in both injectors. The variation in the peak combustion pressure of the narrow angle injector was smaller than that of a conventional injector. In addition, the narrow angle injector induced a higher indicated mean effective pressure (IMEP) and a shorter ignition delay compared to the conventional injector. In terms of exhaust emissions characteristics, the low and stable ISHC and ISCO emissions can be achieved through the application of narrow angle injector to the diesel-bioethanol blends combustion. By the early injection combustion strategy, ISHC and ISCO emissions are significantly reduced.