Refrigerant Gas R134a
Refrigerant R134a, mainly used as a substitute for R12, is widely used in refrigeration and air conditioning systems such as automotive air conditioners, refrigerators, central air conditioners, and commercial refrigeration. R134a has a normal boiling point of -26.5 °C.FREON R134a has a large latent heat of vaporization, a larger heat capacity than constant pressure, and a better refrigeration capacity. The volume of saturated gas is large, the mass flow rate of the refrigerant of the same displacement compressor is small, and the ODP ozone layer has no destructive effect, but the GWP global variation of R134a The warm potential is 1600.
HFC GASR134a has a smaller capacity than R22 and a lower pressure than R22. R134a has a very high water absorption, 20 times that of R22, so the dryer in the unit system is more demanded to avoid ice blockage.
The R134a system requires a dedicated compressor and a special grease. Due to its high water absorption, high foaming and high diffusibility, the grease is inferior to the mineral oil used in the R22 system due to the stability of the system performance.
Refrigerant R134a temperature and pressure comparison table
Refrigerant Gas R404a:
Refrigerant R404a is a mixed refrigerant consisting of 44% R125, 4% R134A, and 52% R143A. The two refrigerants cannot be mixed, R22 is a primary refrigerant, R404a is a mixed secondary refrigerant, azeotropic and non-azeotropic, and the boiling point pressure is different. The refrigerant has an ODP of 0 and a GWP of 4,540.
The exhaust pressure of Freon R404A refrigerant is about 1.2 times that of R22, and the mass flow rate is about 1.5 times that of R22. The exhaust flow rate increases and the resistance increases. In general, the heat transfer capacity of the condenser is increased by 20% to 30% compared to R22.
HFC R404A is a non-azeotropic mixture. The concentration of non-azeotropic mixture changes with temperature and pressure. This brings certain difficulties to the production, debugging and maintenance of the refrigeration system, and also has a certain impact on the thermal conductivity of the system. Especially when the refrigerant leaks, the system refrigerant is recommended to be completely emptied and replaced, so as to ensure the proportion of each mixed component, and also achieve the design cooling effect.
Refrigerant R404a temperature and pressure comparison table