| Abstract [eng] |
The dissertation examines the problems of deviation of energy efficiency and reliability of marine diesel engines from the optimum value, when the engine operates on unregulated fuel in technical documentation. The relevance of the work is determined by the rational selection of marine fuel from a wide range of fuels, depending on the type of diesel engine. Two directions that influence the indicator process of engine work are analysed: fuel spraying phase and fuel chemical combustion kinetics parameters. On the topic of the thesis an analysis of the scientific literature and the marine bunker fuel market has been carried out. In experimental studies of changes in the parameters of fuel jet quality over time, modern non-contact methods have been used: laser diffraction and optical scanning with the threshold segmentation method. The object of the study were 7 types of fuel and two types of ships fuel injection systems: “Common Rail” and “Conventional Design System”. For a more accurate calculation of heavy fuel Sauter mean diameter, a correction of analytical Tanasawa and Toyoda equation was proposed. An assessment was made of the ability to qualitatively determine the dynamics of the jet and to replenish the mathematical models of the processes of the internal combustion engine. The mathematical modeling of the parameters of the main diesel engine types of ships (high speed – “Caterpillar 3512B” [USA] and “MTU 8V 396TB” [Germany]; medium – “SKL VDS 48/42” [Germany] and “ChN 26,5/31” [Russia]; low – “MAN B&W 6S60MC” [Denmark]) was carried out, with engines operating on different marine fuels. Mathematical modeling was used to assess the influence of marine fuel properties (density and kinematic viscosity) on the performance characteristics of diesel engine: specific fuel consumption and reliability parameter. For practical use, monograms and methodological recommendations for the rational selection of properties regulated by the marine fuel standard are presented for different types of diesel engine energy efficiency and reliability criteria. |
