ENERGY PERFORMANCE OF ECO-FRIENDLY RE170 AND R510A REFRIGERANTS AS ALTERNATIVES TO R134a IN VAPOUR COMPRESSION REFRIGERATION SYSTEM

Ozone depletion and the atmospheric greenhouse effect due to refrigerant emissions have led to drastic changes in the refrigeration and air-conditioning technology. For this reason, environmentally benign, 'natural' refrigerants have attracted a considerable attention. In the group of natural refrigerants, hydrocarbons are the most closely related to the HFCs with similar thermodynamic and transport properties, which make them suitable as substitute refrigerants in the existing HFC systems without any major changes in the design. In this paper, the energy performance of two eco-friendly hydrocarbon refrigerants (RE170 and R510A) with zero ozone depletion potential and negligible global warming potential in vapour compression refrigeration system is investigated theoretically under different operating conditions. The results obtained showed that RE170 and R510A have similar saturation vapour pressure characteristics and thermophysical properties with R134a. The Energy performance of both R510A and RE170 was better than that of R134a. The average COPs of R510A and RE170 are higher than that of R134a by 20.7 and 13.1%, respectively. The lowest discharge temperature and energy consumption, and highest COP of the system were obtained using R510A. Generally, R510A and RE170 performed better than R134a; their energy consumptions are 20.4 and 14.1% less than that of R134a, respectively. Therefore, they can be used as drop-in substitutes in the existing R134a refrigeration systems.