Influence of Main Injection Timing on Performance Characteristics of Medium Duty RCCI Engine Operated on Various Blends of Biofuels

The Reactivity Controlled Compression Ignition (RCCI) has the capability to reduce NOx and PM simultaneously without compromising thermal performance. In this experimentation, B20, B10 and diesel were utilised as high reactivity fuels (HRF) and E20, E10 and gasoline were used as Low Reactivity Fuels (LRF). The HRF injection timing was divided into two phases: start of injection (SOI1) and (SOI2). The SOI1 was maintained at 25 deg Before Top Dead Center (BTDC), while SOI2 was varied across 14, 16, 18 and 20 deg BTDC. The influence of variation of SOI2 on combustion, emission and performance characteristics on a single cylinder RCCI engine is assessed. The LRF to HRF ratio was kept about 60:40. From the experimental results, it has been found that, for advanced injection timing of SOI2, there is a reduction in CO and HC emissions, while with retarded injection timing, there is a rise in emission of NOx and smoke opacity. Brake specific fuel consumption increases for both advanced and retarded injection timings.