만액식 해수냉각시스템의 특성에 미치는 열원수 온도의 영향

Abstract

As effects of maritime law revision, disputes to obtain sea area have been frequently occurring throughout the world. In case of South Korea, South sea bordering China and East sea connecting to Japan are exposed to continuous conflicts due to competing profits of each country. Especially, issues that not authorized vessels from China invade have been continuously happening. This causes decrease of fishing species and lack of the quantity. Moreover, unconscious fishing of fries is resulting in destruction of fisheries. As a solution of these problems, methods for extending operation period and maintaining freshness are required to increase income of fishery operators. Fishing vessels in littoral sea consist a fleet to operate fishing, and separated carrying vessels are included in it. During the operation, plain ice is used to cool seawater in the fish storages of most carrying vessels. In this case, unevenness of salinity and temperature within the storage are easily occurred resulting in difficulties to maintain freshness of catches. To complement this problem, carrying vessels applying a cooling system directly chilling seawater are already introduced in some developed countries. In the case of South Korea, the related researches are being conducted for the advanced marine industry. Therefore, the studies about increase of working time on vessels and maintenance of catches’ added value as a high level are essential. In this study, the 15 kW-class experimental apparatus of the seawater cooling system is manufactured to conduct an experiment about performance characteristics of it. Then, the temperature of cooling water is increased from 19℃ to 29℃. As a result, compression ratio is increased according to increase of outlet pressure at a compressor and figures of theirs rate of increase are about 12% and 27%. And a flow rate of working fluid is increased about 12% because of a decrease of a refrigerating effect, which means enthalpy difference between inlet and outlet of an evaporator. Also, a condensing capacity is increased about 9% and a compressor work is increased about 19% because of increase of flow rate of working fluid. Consequently, a COP is decreased from 3.7 to 3.0, about 18%.