Eco-Diesel Engine Fuelled with Rapeseed Oil Methyl Ester and Ethanol. Part 3: Combustion Processes

Abstract

In Part 1 of the paper efficiency and emissions of the engine fuelled with rape oil methyl ester (RME) and ethanol were presented and discussed. In the second part of the paper a comparison of emissions and brake fuel conversion efficiency of the engine for two base fuels, diesel fuel and rape oil ethyl ester, was carried out. In this paper, Part 3, combustion processes are investigated. Experiments were carried out on the same single-cylinder direct injection compression ignition engine as in Part 1. In the course of the experiments the pressure-time history of the engine cylinder and instantaneous parameters of injection of the RME fuel were measured and used to calculate the rate of heat release and the fraction of fuel burnt versus crank angle, which showed that the higher the energy fraction of ethanol in the total fuel, the longer the ignition delay but the shorter the total time of combustion. It was found that shorter combustion results in higher efficiency.