摘要：In this paper, a bench test of a two-cylinder diesel engine with high-pressure common rail direct injection (CRDI) system for the external characteristics was carried out. The shape of combustion chamber was determined by comparing the fuel economy and soot emission of diesel engines. Based on this result, the effects of different nozzle parameters attempted at reducing brake specific fuel consumption (BSFC) and smoke were investigated. The experimental results show that the improved combustion chamber with a high central convex platform can significantly reduce BSFC and it has little impact on smoke. The appropriate decrease of the nozzle tip penetration (NTP) as well as increase of nozzle-hole diameter contribute to reducing fuel consumption and soot emission. The BSFC at the spray angle of 156° is reduced by 16% at the engine speed of 4000 r/min compared with that at the spray angle of 150°. Comparative results on fuel consumption and smoke emission at all engine speeds reveal that the injector with 153° spray angle, 1.8 mm NTP, 6 injection holes and 0.12 mm nozzle-hole diameter is a better choice of the two-cylinder diesel engine.
