Sagin S. Theory and practice of energy conversion on ships with minimal inevitable irreversible losses

The dissertation research is aimed at solving an applied scientific problem – energy conservation in propulsion systems of a transport vessel. Technologies have been developed that provide control over irreversible losses under various operating conditions of the ship propulsion unit of sea and river vessels. The control of minimally unavoidable energy losses during the rotational movement of the contact nodes of marine diesel engines (in particular for the tribological system ‘the crankshaft – lubricant – bearing shell’) is ensured by maintaining the optimal term of replenishment of the lubrication system (which, in turn, is determined by the dynamics of changes in the rheological characteristics of the oil) and adding into the volume of the lubrication system (directly in front of the engine) of an optimum concentration surfactant (which is determined by preliminarily laboratory optical and tribological researches). The minimally unavoidable losses during the forward motion of the contact nodes of marine diesel engines on sea and river vessels (in the tribological system ‘the piston ring – lubricant – cylinder liner’) are controlled by adding an optimum concentration surfactant to the cylinder lubrication system. The control of minimally unavoidable energy losses under high dynamic loads (in the tribological system ‘the plunger – lubricants – high pressure fuel pump liner’) is achieved by implementing an oriented molecular structure in the fuel boundary layers due to the additional application of a stable layer of organic coatings on the contact surfaces. The implementation of the results of the dissertation research on sea and river vessels indicates 1.48...2.35-fold wear reduction in the above mentioned tribological systems; 6.3...10.8 % reduction in burning oil consumption; 1.3...2.5 % reduction in specific fuel consumption; 3.9...14.7 % reduction in the power of mechanical losses, which helps to reduce financial costs from 100 to 250 $/day for the operation of sea vessels in the territorial waters of Ukraine and from 200 to 600 $/day for such operations in territorial waters of the countries of the European Union and the World Ocean. Key words: ship propulsion unit, mechanical losses, marine diesel, boundary lubricating layer, control over energy losses, mechanical efficiency.