Evaluation of performances in DI Diesel engine with different split injection timings

Abstract

Abstract An injection mechanism which is split injection was found to reduce emissions in Diesel engines. In this mechanism, split injection proportion and split injection timing was varied and analyzed to reduce engine emissions. Injection proportion was varied at 25% of the pilot and 75% of the fuel as main injection and timing as 54° ATDC (after top dead center) and 40° ATDC for split injection. Since a homogeneous mixture occurs in this pilot injection, combustion is becoming complete for Diesel Engine. Hence, BTE was increased by 1.5% for timing 40° ATDC and 12° BTDC (before top dead center) and reduced by 1.4% for timing 54° ATDC and 12° BTDC. The reduction in BTE for 54° ATDC is because the increase in timing increases cooling effect of air and combustion rating was reduced. Also, combustion takes place at low temperature itself due to homogeneous mixture. So, NOx emission was also reduced by 8.4% and 18.6% for 40° ATDC and 54° ATDC injection timing respectively. The other emissions like HC and CO were also observed to be reduced upto 35% and 11% respectively due to increase in homogeneous mixture in Diesel Engine.