Application of Environmental Friendly Material R32/R1234ze in Heat Pump Water Heater

摘要

With the refrigeration equipment working medium transition from high GWP to low, it is significant to study the environmental friendly refrigerant to protect the environment and avoid the greenhouse effect. Through theoretical analysis and experimental study of R32 and R1234ze mixtures, this paper provides the reference for the application of mixed refrigerant in the heat pump water heater. Based on REFPRO 9.0 and KW2 model parameters, this paper calculated the thermophysical properties of mixing refrigerant R32/R1234ze; according to the heat pump water heater test standard, figured out cycle performance of mixed refrigerant in different ratios. The results showed that the optimal mixture ratio is 0.7/0.3. Applying this ratio, in different operating conditions, the refrigerant performance tests are conducted in comparison with R410A on heat pump water heaters. The results indicate that, with the R32 and R1234ze refrigerant mixture under the ratio of 0.7/0.3, the compressor power consumption and discharge pressure are lower, which is conducive to the safe and stable operation of the water heater unit. But the system COP is higher than R410A, and the decline rate of COP is lower when the temperature is higher than the standard conditions. Therefore, the mixed refrigerant is feasible to replace R410A.