18 May 2017

O.4.1.2 Thermodynamic Performance Assessment of R32 and R1234yf Mixtures as Alternatives of R410A

HFC refrigerants with high Global Warming Potential (GWP) including R410A will be phased down to meet
the new historic agreement under the Montreal Protocol. To develop a suitable alternative refrigerant for R410A
which could meet the requirements of both system performance and environmental performance, the use of
refrigerant mixtures of R32 and R1234yf was investigated in the present study. First, a comparison of
thermodynamic properties, heat transfer coefficients and GWP values of R410A, R32, R1234yf and
R32/R1234yf mixtures was conducted. When the R32 mass fraction is about 0.218, the GWP of the
R32/R1234yf mixture reaches to 150. Second, the cycle performance of a single-stage refrigerating/heat pump
system operating with different refrigerants was analyzed theoretically. Calculation results of R32/R1234yf
mixtures show that both the condensing pressure and discharge temperature increases with an increase in R32
mass fraction while the cooling and heating capacities increase. When the R32 mass fraction is 0.218, the
heating and cooling capacities of the mixture are lower than those of R410A by 13.5% and 17.6%, respectively
but the heating and cooling COPs of this mixture are comparable to those of R410A, respectively. However,
with the R32 fraction higher than 0.45, those of R32/R124yf mixtures can be even higher than R410A.