Comparative analysis on single, double and triple fuel injection strategy of single cylinder RCCI engine fueled with ethanol-gasoline/diesel-biodiesel blends

Abstract

This experimentation attempts to investigate the parametric and comparative analysis of single, double and triple injection strategies of DI (direct injection) for modified constant speed non road single cylinder RCCI engine. The blends of ethanol-gasoline and diesel- jatropha biodiesel were used as a low reactivity fuel (LRF) and high reactivity fuel (HRF), respectively. The ratio of LRF and HRF was 60:40. The following parameters were employed in this experiment: 12% hot exhaust gas recirculation (EGR), 3 bar PFI (port fuel injection) pressure, and 500 bar HRF injection. In the case of single injection strategy, injection timing was −25 deg atdc with 100% mass, for double injection strategy −40 deg and-18 deg atdc with 40% and 60% mass and triple injection, −31 deg, −21 deg and −11 deg atdc with 30%,30% and 40% masses respectively. All the tests were performed at 1500 rpm speed and under various loading conditions ranging from 0 to 12 kg in increments of 4 kg. Results were compared with a double injection strategy for 12 kg loading conditions. It has been observed that for single injection 6% reduction in HC emission,67.5%,25% and 2% rise in NOx, CO and smoke opacity respectively, while for triple injection strategy, 25 % and 41.78% rise in HC and NOx emission and 8% and 15.78% reduction in CO and smoke opacity respectively . From the results it has been concluded that proper tuned multiple injections of the biofuelled RCCI operation have great potential to reduce the emission constituents without affecting the performance of the engine.