Combustion Stability Investigation of Ethanol Blends (E05, E10) in a Twin-cylinder CI Engine 2022-01-0521

Rapid population growth and fuel crisis due to limited availability of fossil fuels, led the research in the fields of alternative fuel for the replacement of conventional fuels. The petroleum-like characteristics of ethanol make it an excellent alternative fuel for the internal combustion (IC) engines. It can be easily derived from waste agricultural resources such as plant biomass and forest residue, ease of production increases the possibility of its utilization locally in the agricultural engine and transport vehicles. A laboratory experiment was carried out, using a common rail direct injection (CRDI) diesel engine at varying load conditions (no-load, 20 Nm and 40 Nm) with two ethanol blends (5% and 10% v/v indicated by E05 and E10) and diesel (D100) to explore the combustion stability, combustion behaviour and emissions parameters of ethanol in existing compression ignition (CI) engine. The maximum in-cylinder pressure and heat release rate (HRR) were increased with ethanol addition into diesel. Ethanol’s higher latent heat of vaporization promotes cooling effects that prolong ignition time. Inherent oxygen and lower viscosity of ethanol improve the combustion phenomena, which results in the lower cycle-to-cycle variation and lower coefficient of variation (COV) for indicated mean effective pressure and peak in-cylinder pressure. Combustion stability was increased with the addition of ethanol. E10 is showing the lowest COV_imep value (3.01%), then E05 (4.2%) followed by D100 (6.78%). Lower standard deviations were observed for E10 fuel throughout the combustion, representing stable combustion among tested fuels (D100 and E05) in test conditions (40 Nm). Lower carbon to hydrogen ratio and stable combustion, decrease CO, HC and smoke emissions by a substantial amount in the tailpipe with the increasing amount of ethanol in blends compare to base fuel.