Experimental study of a dual-fuel generator set operating on diesel fuel direct injected and hydrous ethanol fumigation at different loads

Abstract

The sizable global use of fossil energy and the worries about harmful emissions to the environment and human health have led investigations focused on using renewable fuels. Ethanol seems to be a desirable renewable fuel due to availability and significant production. The ethanol fumigation in compression ignition engines has been explored as a possible solution to enhance efficiency and decrease harmful and pollutant gases. This study investigates the effects of a generator set running on directly injected diesel fuel containing 7% biodiesel in volume and port fuel injected hydrous ethanol in different loads. The experiments were carried out in a diesel engine with specific loads, and the ethanol substitution rate ranged from 9% to 52% by energy. Results showed a significant decrease up to 61% in smoke opacity. An improvement of about 9.7% at 7.0 kW in global thermal efficiency was observed. Nevertheless, the other loads' efficiency deteriorated, resulting in a maximum decrease of about 14.6% at 4.0 kW. The total specific fuel consumption increased when ethanol was used, whereas the exhaust gas temperature decreased. The lowest NOX emissions found was 290 ppm at 6.0 kW and an ethanol energy ratio of 21%, although an increase in CO emissions was observed.