Study On New Refrigerant Mixtures As Alternatives To R22

Widely using of R22 in the filed of refrigeration and the date of phased out earlier make the project of substitute emphasis on working fluids study. Considering the existing condition, there are many difficulties in using the pure substance as substitute. So we chose the mixture as the substitute routine.Start form the viewpoint of environment protect, using the criterion of alternative refrigerant selection and according to the principle of combination, many mixtures HFC and HC contained are studied in this paper. At first a calculation mode is established based on a theory circle, then the effect of each composition on the environmental properties, thermal performances and safety of mixtures as a whole are analyzed. According to certain principle, optimization on mixture ratio is conducted and refrigerant mixture R32/R134a/R227ea(20/60/20wt) is determined as the alternative to R22 used in existing equipment at last.Theory calculation results show that the thermal characters of new working fluid match to R22, COP is slightly less than R22, q_v is more than R22 a little. Moreover its priority to R410 is lower condensing pressure, even below R22. The most important is that it is environmentally friendly, ODP=0, GWP=1470(calculated by mass ratio), both below the value of main alternative R407C and R410A.The performance of new working fluid is also tested on the electric calorimeter apparatus for refrigeration performance measurement designed according to GB5773-86, compared to the experiment results of R22. It shows that it can match to R22 both in COP and capacity. The disadvantage is the considerable great temperature glide, so it should be careful deal with, avoiding refrigerant leakage influence on system. If the heat transfer can be changed in reverse flow way, the efficiency of system can be greatly raised.