Experimental and numerical investigations on the combustion and emission characteristics of an ethanol/diesel dual-fuel engine

摘要

Experiments and simulations were conducted to investigate the combustion and emission characteristics of ethanol/diesel dual-fuel combustion. The experiments were performed on a light-duty diesel engine with direct injection of diesel combined with port injection of ethanol. The results showed that the ethanol/diesel dual-fuel mode could reduce soot and NO_x emissions simultaneously without EGR even at the higher load. However, the UHC and CO emissions of the ethanol/diesel dual-fuel mode increased gradually with the increase of ethanol proportion. Simulations showed that high UHC and CO emissions were formed in the crevice regions as well as cylinder center due to the lower reactivity of ethanol. It was also found that the cyclic variations of the ethanol/diesel dual-fuel mode increased gradually with the increase of premixed ratio at both loads. This was mainly due to the lower reactivity of ethanol.