ENERGY EFFICIENCY ANALISYS OF A MARINE REFRIGERATION PROCESS

Marine transportation is very convenient due to its very low costs. Due to the constant growth of population and its food demand, marine refrigeration is an attractive business.

The purpose of this work is to find a way in order to enhance the total energy efficiency of a marine refrigerating plant working with R 134 a. In this study will be make a comparative analysis of the performance of a vapour compression refrigerating plant- met in marine transportation of perishables goods. The temperature values of the sea water at the inlet and outlet of the condenser will be considered to be 23, respectively 26 Celsius degrees.

By studying the main parameters of the refrigerating plant cycle, we can establish the value of the convenient refrigerated power, so that the process is streamlined to the fullest. This work is in accordance with the measurements of the water temperature of the seas and oceans, at a depth of 2-3 meters, during the summer period. Depending on the temperature fluctuation, it has different values on the surface, but retains a constant value of 23-26 degrees at the indicated depth. Between the main parameters calculated in this study are the following: the mass flow of the refrigerant (qm), the total thermal power of the condenser (ΦRHE), total power input at the compressor (Pc) and Coefficient of Performance of the plant (COP). Considering that on board the ships, refrigerating effect might have different values, depending on the type of the ship, this study focuses on very clear criteria related to the cold production in optimum conditions. In this paper the refrigeration effect will take this three different value: 20 kW, 25 kW and 30 kW. On this bases will result three situations which will be analysed comparatively.

Will be analysed the main values: the mass flow of the refrigerant, the total thermal power of the condenser, the power input of the compressor and the Coefficient of Performance. According to the above mentioned, will be possible to be indicate which is the best operating situation, among the three cases of study.