R507 and R404A refrigerants.
R507 and R404A can be used as environmentally friendly refrigerants to replace R502, but they are not identical.
R507 is a hybrid refrigerant consisting of R125 and R143A, R507 has a higher evaporation temperature and lower condensing temperature, so it can replace R502 in a wider range of applications, R507 is an azeotropic mixture that can be charged in liquid or gaseous form. In addition, R404A is added to R134A, which reduces mass transfer resistance and increases heat transfer coefficient. In contrast, R507 has a higher heat transfer coefficient than R404A.
The evaporation temperature of R507 is -467, the freezing point is -488. The gasification temperature is -476℃。Due to its good refrigeration performance, R507 is widely used in refrigeration and refrigeration equipment and supermarket refrigeration systems.
R404A is also a mixed refrigerant, consisting of R125, R143A, and R134A, R404A has a lower evaporation temperature and a higher condensing temperature, so it is commonly used in low-temperature applications, and R404A is a non-azeotropic mixture that needs to be charged in liquid form when filled. It is also a colorless and transparent liquid with low toxicity, odorless and non-flammable properties similar to R507.
The evaporation temperature of R404a is -454. The freezing point is -507. The gasification temperature is -465℃。Also because of its excellent refrigeration performance, R404A is widely used in refrigeration equipment and supermarket freezers.
The R507 shows advantages in a number of ways. First of all, since R507 is an azeotropic refrigerant, its slip temperature is lower than that of R404A. This means that after multiple leaks and charges, the composition of R507 changes less, while R404A has a larger change.
The volumetric cooling capacity of R507 will not change at most, while the volumetric cooling capacity of R404A may be reduced by about 16%。
Using the same compressor, the R507 has a 7%-13% greater cooling capacity than the R22, while the R404A has a 4%-10% greater cooling capacity than the R22.
This suggests that the R507 may be better in terms of refrigeration.
The heat transfer performance of R507 is better than that of R404A, with or without lubricating oil. This is also one of the advantages of the R507 in some applications.