| Popis: |
In this study, the use of the alternative refrigerant R513A instead of R134a in a mechanical vapor compression refrigeration system was experimentally investigated in terms of the first and second laws of thermodynamics on the basis of the Kigali Amendment. The investigations were carried out approximately at a cooling medium temperature (TL) of 0, 4, and 8 °C and a heating medium temperature (TH) of 30, 35, and 40 °C without any modifications to the system. The energetic and exergetic performance parameters obtained in this study were related to the amount of refrigerant in accordance with the criteria restricting the use of fluorinated greenhouse gases after the Kigali Amendment. Accordingly, the required refrigerant mass flow rate per unit energetic (power input, cooling capacity, COP value) and exergetic (total exergy destruction rate and exergy efficiency) performance parameters were determined. As a result, the system was found to operate safely when R513A was used instead of R134a without any modification. In addition, the refrigerant mass flow rate per unit power input was almost the same for both refrigerants. However, R513A was found to have approximately 15 % more refrigerant mass flow per unit cooling capacity than R134a. This resulted in the refrigerant mass flow rate per unit COP being approximately 20 % higher for R513A. On the other hand, the refrigerant mass flow rate per unit exergy efficiency calculated for R513A was found to be about 15 % higher than R134a. |
