THE PERFORMANCE AND EMISSION CHARACTERISTICS OF FISH OIL METHYL ESTERS (FOME) AND DIESEL BLENDS IN A PARTIALLY PREMIXED CHARGE COMPRESSION IGNITION ENGINE

In the present work, an attempt was made to reduce NOx and PM using partially premixed charge compression ignition (PPCCI) combustion of diesel fuel with external mixture formation technique and fish oil methyl ester (FOME) blend in the main injection. Not much work has been done related to the usage of bio-diesel (Methyl esters of edible, non-edible oils, and animal fats) in the PPCCI combustion mode. Diesel fuel was injected into the intake manifold to form homogeneous pre-mixture beforehand and the pre-mixture is burnt in the cylinder with the balance quantity of fuel directly injected into the cylinder by a conventional injection system. To obtain homogeneous mixture, diesel fuel was injected in the intake manifold using a solenoid-operated injector controlled by Electronic Control Unit (ECU). Exhaust Gas Recirculation (EGR) technique was adopted to control the start of combustion (SOC). Experiments were conducted with 10%, 20%, and 30% EGR for premixed ratio (Rp) 25% and results are compared with conventional diesel fuel operation. It is observed that diesel manifold injection and FOME blend in main injection results in better mixture preparation and lower emissions. Due to homogenous lean operation, significant reduction in NOx and PM are achieved with the PPCCI combustion mode at Rp 25% and EGR 20% in the FOME-Diesel mode of operation.