Thermal efficiency of environmentally friendly closed cooling systems of marine power plants

Abstract

The issues of heat removal efficiency of cladding heat exchangers of closed cooling systems of ship power plants are considered. The use of such systems allows obtaining technical and environmental advantages in the operation of the vessel. The latter ensures the conservation of fish resources of the seas and continental waters. It is shown that the worst conditions for heat removal take place when the vessel is parked. In this case, heat transfer to outboard water is carried out with free convection. This mode is the main calculation mode. In the case of vessel movement, heat removal increases significantly, since it is carried out with forced convection. For the case of the ship berthing, the results of experimental thermal engineering studies on a model of 1m² are presented. It is shown that the efficiency of heat removal significantly depends on the orientation of the ship’s plating of the temperature difference in the apparatus. The transition from the bottom location of the apparatus to the side, as well as an increase in the temperature difference, provide greater thermal efficiency. Generalizing similarity equations are obtained for the case of the ship berthing. Based on them, a method for the calculation has been developed. The reliability of this technique is fully confirmed by the results of testing such a heat exchanger, with an area of 100 m², on a self-propelled floating crane of project 15201. It is shown that the obtained generalizing similarity equations have their own characteristics compared to the known ones. This is a consequence of the peculiarities of the processes taking place in such devices. For the case of vessel movement, generalizing similarity equations are also obtained. In this case, the authors have used the results of their own tests of such devices on the floating crane of project 15201, as well as the tests results of other researchers on various ships.