Influences of pilot injection, main injection and EGR on performance combustion and emissions in an HCCI-DI combustion engine using with Diesel and WPPO bio-diesel blends

The present study involves the different SoMI timings (18 degrees, 20 degrees, 22 degrees and 24 degrees BTDC), SoPI timings (30 degrees, 35 degrees and 40 degrees BTDC) and without EGR and with 5%, 10%, 15% EGR at constant FIP and engine speed 600 bar and 1500 rpm were tested in order to identify their impacts on performance, combustion and emission characteristics in an HCCI-DI engine. In this experiment we use diesel, bio-diesel WPPO as fuel at various mixing blends (WPPO 5%,10%,15% and 20% by volume) of biodiesel. The results showed that a 55.05% reduction of in NOx was achieved using SoMI 24 degrees BTDC and SoPI 40 degrees BTDC timings, and with 15% EGR and also showed that the smoke opacity (22.53%) was decreased without EGR, while the BTE was decreased as the SoPI timing and EGR percentage were increased. However, there was a 50%, 8.8% reduction in UHC and CO emissions without EGR as compared with diesel fuel.