An experimental investigation on performance and emission characteristics of eucalyptus oil-diesel blends at various injection timings in a D.I. diesel engine

Experimental investigations were carried out to study the performance and emission characteristics of a D.I diesel engine running on eucalyptus oil-diesel blends. Eucalyptus oil is derived from biomass and is renewable. Various eucalyptus-diesels blends namely 20:80, 30:70, 40:60, 50:50 (by volume) were tried. The optimum quantity of eucalyptus was chosen as 40% based on the performance. The injection timing was advanced to ensure adequate mixing and vaporization of high-octane fuel-diesel blends. With advanced injection timings it was noticed that there was a better performance with decrease in emissions of UBHC, CO than at standard injection timing. Smoke emission decreased drastically with penalty of slightly higher NOx emissions. The engine was operated at the injection timings of 23°, 27° and 31° bTDC. The performance and emission characteristics were analyzed at these timings for all the blends. At 31° bTDC, NOx increased drastically with poor combustion behavior. At the injection timing of 27° bTDC the engine was running smoothly with better performance and emission characteristics, hence injection timing 27° bTDC was optimized for this work and the effects are presented in this paper. For the Eu 40 blend there was an increase of 2.5% brake thermal efficiency with 22% reduction on smoke emission at the penalty of 8.5% hike in emissions of oxides of nitrogen.