OPTICAL RESEARCH ON THE FUEL INJECTION INTO A DIESEL ENGINE FOR DIESEL FUEL, RME AND RAPE OIL

Abstract

The paper presents the results of the research on the influence of diesel fuel, rape oil methyl esters and rape oil on the evolution of the jet, velocity of the jet front and the atomization/spraying apex angle versus the crank angle of the engine. Measuring was performed using a single-cylinder Diesel engine with direct fuel injection and the apparatus AVL Engine VideoScope. It was found that physical and chemical parameters diversifying the tested fuels significantly influence the parameters of the sprayed fuel jet. It applied mainly to the increase of the fuel atomization apex angle for the fuels of high viscosity as compared with diesel fuel and to different course of the range and velocity of the jet front versus the engine crank angle. Large and heavy drops of vegetable oil have initially higher velocity than for diesel fuel. However, very soon, the velocity of rape oil jet front decreases to a lower value than for the petroleum fuel. From the visualisation process we can observed real start of injection and combustion processes. From these measure - delay of self-combustion in diesel engine. Delay of self-combustion for natural rapeseed oil is shorter than for standard diesel fuel. As a result of this fact, we can observe in next research lower combustion dynamic, lower max. combustion temperature and lower concentration of NOx in exhaust gases. A change of the organization of the injection process of tested fuels can bring on differences in the combustion course.