ASSESSMENT OF THE RELIABILITY OF MARINE DIESEL ENGINES ACCORDING TO THE TECHNICAL CONDITION OF ENGINE OIL OF CIRCULATING LUBRICATION SYSTEMS

Abstract

The results of research are given in relation to the assessment of failure-freeness of marine diesel engines based on the technical condition of the motor lubricant of circulating lubrication systems. The research was carried out on marine four-stroke Volvo Penta TMDA 163A diesel engines, which perform the functions of auxiliary engines of a specialized marine vessel with a deadweight of 10,850 tons, in the circulation lubrication systems of which motor lubricants with different characteristics were used. It has been proven that the main operating indicators of motor oil, which determine and ensure the trouble-free operation of marine diesel engines, are the total alkaline number and the rate of its reduction, as well as the content of mechanical impurities in the motor oil, which characterize the wear of diesel engine parts and contamination of the oil. It has been experimentally established that motor lubricants characterized by a lower rate of reduction of the total alkaline number provide better lubrication of marine diesel engines, which is reflected in an increase in the hydraulic density and lubricating capacity of the lubricant. Confirmation of this (when comparing motor oil, the rate of decrease of the total alkaline number of which is less with other oil) is a slower decrease in pressure at the end of the compression process (which characterizes less wear in the diesel friction pairs) and a decrease in the temperature of the exhaust gases (which characterizes a higher hydraulic density in the coupling piston ring - cylinder sleeve). It was also established that during an intensive decrease in the total alkalinity of motor oil, its technical condition deteriorates, which is manifested in an increase in mechanical impurities (which are the result of its oxidation or wear of diesel engine parts) entering its volume. Over time, this reduces the lubricating capacity of engine oil and reduces the reliability of diesel engines. The obtained results indicate the possibility of diagnosing the failure-free operation of marine diesel engines due to the technical condition of the motor lubricant used in its circulating lubrication system.