Refrigerant R404a is a mixed refrigerant, which is composed of 44% R125, 4% R134A, and 52% R143A. Two refrigerants cannot be mixed. R22 is a primary refrigerant, and R404a is a mixed secondary refrigerant, azeotropic and non-azeotropic, the boiling point pressure is different. The ODP of the refrigerant is 0, and the GWP is 4540.
The discharge pressure of 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. Generally speaking, the heat exchange capacity of the condenser is increased by 20% to 30% than R22.
R404A is a non-azeotropic mixture working fluid. The component concentration of the 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 heat transfer performance 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 achieve the designed refrigeration effect.