ANALYSIS OF A VAPOUR COMPRESSION REFRIGERATION SYSTEM WORKING WITH R22

Abstract

Marine refrigeration has to comply with environmental constraints and with efficiency improvement as well. R22 was a refrigerant governing marine refrigeration systems. After 2020, it is legally in use in old systems, relying on recycled supplies, because of its poor environmental properties. In this paper, it is developed a theoretical analysis of a single stage vapour compression system working with R22, on basis of energy and exergy analysis. The thermodynamic analysis consists in the assessment of the influence of evaporator temperature on the performance of the system- by the use of the laws of thermodynamics. The evaporation temperature varies in the range (6.5-9.5) oC, when the ambient temperature is 28oC.The obtained results will show that the Coefficient of Performance will increase together with the evaporator temperature increase, while the specific work consumption and specific total exergy destruction will decrease. For the maximum considered value of the evaporator temperature, COP value increases with 14% in comparison with the value obtained for the minimum evaporator temperature. In addition, the specific work consumed by the compressor will decrease with 5.81%, while for the specific total exergy destruction the decrement is of 2.4%. Seen that for the highest evaporator temperature it is reached the performance improvement, for 9.5oC are also determined the exergy destructions in the main components of the system. It is found that in the compressor, in the evaporator, in the condenser and in the throttling valve, exergy losses are 5%, 36%, 56% and 3%. Exergy analysis reveals that the most inefficient components of the system are the two heat exchangers of the system.