Exergy analysis of a cooling system: experimental investigation on the consequences of the retrofit of R22 with R422D

In this article, the performances of a walk-in air cooler working with R22 and its substitute R422D are experimentally studied. To define a full comparison on the performance characteristics of R22 and R422D, both an energetic and an exergetic analyses are proposed. The experimental investigation was carried out considering four levels of refrigeration capacity: 920, 1340, 1925 and 2250 W. All tests were run at steady-state conditions and by keeping the value of the external air temperature equal to 228C. The experimental analysis allowed the determination of the COP, the exergetic efficiency, the exergy flow destroyed in each component and other variables characterizing the working of the plant. The results demonstrated that COP of R422D is, on average, 20% lower than that of R22. Furthermore, for plant whose condenser is air cooled, R422D could lead to increase the fan speed or to adopt bigger blowers