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 ecofriendly
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.