EFFECTS OF INJECTION TIMING ON COMBUSTION PERFORMANCE AND EMISSIONS IN A DIESEL ENGINE BURNING BIODIESEL BLENDED WITH METHANOL

Abstract

Currently, biodiesel has been received much attention from many researchers around the world due to its clean and renewable characteristics. In the present study, combustion and emissions characteristics have been studied on a modified four-cylinder, 4-stroke, water-cooled, direct injection compression internal engine equipped with a common rail fuel injection system fueled with methanolbiodiesel blends as well as pure biodiesel. The experiment was operated at a constant engine speed of 1800 rpm and injection timing from 2.5-22.5 ° crank angle before top dead center. With the injection timing advanced, peak in-cylinder pressure and maximum heat release rate increased while combustion start points were advanced. Ignition delay was shorten first and then prolonged while brake thermal efficiency was increased first and then decreased. With the injection timing in advance, NOx emissions increased, 1,3-butadiene and benzene emissions decreased while hydrocarbon and acetaldehyde emissions decreased first and then increased, and soot emissions increased first and then decreased.