Combustion processes in C.I. engine fuelled with rape oil methyl ester and ethanol

Combustion processes in C.I. engine fuelled with rape oil methyl ester (RME) and additionally with ethanol injected into the inlet port were investigated. The aim of ethanol injection is to enhance combustion of the droplets of base fuel - ester. Experiments were carried out on single - cylinder D.I. C.I engine. In course of experiments engine performance, emissions and pressure in the cylinder were measured. Measured pressure - time history in engine cylinder and instantaneous parameters of injection of RME fuel were used to simulate the rate of heat release and the fraction of fuel burnt vs. 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. Shorter combustion results in higher efficiency. Fuelling the engine with ethanol results in smokeless combustion and lower emission of carbon dioxide (due to higher fraction of hydrogen in ethanol molecule than in base fuel) and with vegetable (renewable) fuel - rape oil methyl ester - results in decrease carbon dioxide emission to the atmosphere.