Avaliação experimental do desempenho do R-32 como substituto do R-410A em um sistema de refrigeração

Abstract

The following paper presents an experimental evaluation of a cooling system using R410A, verifying if the refrigerant R32 is a possible substitute due to its considerably lower GWP. This research was motivated by the current necessity to find alternative refrigerants that have the lowest impact possible to the environment. To make this work possible, an experimental cooling bench was setup, with nominal capacity of 5 TR (~15,6 kW) so that it was possible to obtain operational parameters such as: cooling capacity, compressor power consumption, coefficient of performance and compressor discharge temperature. The environmental impact was calculated by using the TEWI methodology. Tests were performed varying the evaporation temperature between -7 and 7 °C, while the condensing temperature was maintained in 41 °C. Besides the evaporation temperature, the compressor operation frequency was varied from 45 to 60 Hz. The results obtained showed that compressor power consumption using R32 increased from 3 to 5% when compared to R410A. The cooling capacity presented itself 3 to 7% higher when using R32. The Coefficient of Performance was 2 to 8 % better when using R32. The compressor discharge temperature was 20 to 30 °C lower when using R410A. To all evaluated test conditions, the Coefficient of Performance and cooling capacity were higher for R32, therefore concluding that R32 performance was superior than R410A performance. Finally, calculating the for both analysed refrigerants, it was noticed that direct impacts were reduced using R32, mostly due to its lower refrigerant mass in the system and its considerably lower GWP. On the other hand, due to higher power consumption, indirect impacts were higher for R32.