Assessing the potential of ethanol in the transition of biodiesel combustion to RCCI regimes under varying injection phasing strategies: A performance-emission-stability and tribological perspective

Abstract

This investigation demonstrated a split-injection endeavour fuelled with biodiesel-ethanol strategies’ synergistic capabilities to meet the CI engine's emissions-performance-stability prospect. The split injection attempt at different injection angles for each pilot and main injection. Here ethanol was injected into the inlet manifold for various periods. Analysis of the COVIMEP response from each injection technique showed that the corresponding test engine was more stable when powered by biodiesel instead of diesel or biodiesel-ethanol dual fuel. Except for a few cases, the engine’s stability was found within the acceptable limit powered by dual fuel. The maximum Exergy Efficiency and minimum Equivalent Brake Specific Energy Consumption were 48.79% and 21.03% better than biodiesel operation, 45.19% and 27.36% better than diesel operation. The results have shown that the minimum values of NOx, Soot and UHC of biodiesel-ethanol operation are 12.15%, 121%, 12.90% lower than Biodiesel 256.70%, 87%, 9.67% lower than diesel, respectively. This study also demonstrated various tribological aspects of lube oil through degradation rate analysis. Thus, the study revealed synergistic advantages of an existing CI engine running with Split Injection mode to achieve adequate performance and emission characteristics through biodiesel-ethanol RCCI techniques.