R717 (Ammonia)
Ammonia R717: Ammonia is currently the most widely used medium pressure refrigerant. The solidification temperature of ammonia is -77.7 ℃, the standard evaporation temperature is -33.3 ℃, and the condensation pressure is generally 1.1~1.3MPa at normal temperature, even when the cooling water temperature is as high as 30 ℃ in summer, it does not exceed 1.5MPa. Mainly used in large-scale industrial refrigeration and commercial refrigeration field.
◆ Easy to obtain, low price, moderate pressure, large unit cooling capacity, high heat release coefficient, almost insoluble in oil, small flow resistance, easy to find when leaking. But there is a pungent odor, toxic, can burn and explode, and has a corrosive effect on copper and copper alloys.
R22
◆ R22:R22 is a medium temperature refrigerant with a standard boiling point of -40.8°C. The solubility of water in R22 is very small. It dissolves with mineral oil. R22 does not burn or explode. It is very toxic. R22 has strong permeability and is difficult to find leakage.
◆ Widely used in air conditioning, heat pump, dehumidifier, freezer dryer, cold storage, food refrigeration equipment, marine refrigeration equipment, industrial refrigeration, commercial refrigeration, refrigeration condensing unit, supermarket display cabinets and other refrigeration equipment.
R134a
As an alternative refrigerant to R12, R134a has very low toxicity and is not flammable in air. Guangfa is used in: refrigerators, freezers, water dispensers, automotive air conditioners, central air conditioners, dehumidifiers, cold storage, commercial refrigeration, ice chillers, ice cream machines, freezing condensing units and other refrigeration equipment
The chemical stability of R134a is very good, however, because of its high water solubility, it is unfavorable to the refrigeration system. Even if there is a small amount of water, acid, carbon dioxide or carbon monoxide will be produced under the action of lubricating oil, etc., which will corrode the metal or produce "copper plating", so R134a has higher requirements for drying and cleaning of the system.
R404A
◆ R404A is a mixture of HFC125, HFC-134a and HFC-143. It is a colorless gas at room temperature and a colorless transparent liquid under its own pressure. It is a non-azeotropic mixed refrigerant without chlorine. Suitable for medium and low temperature new commercial refrigeration equipment, transportation refrigeration equipment and refrigeration equipment.
◆ R404A is mainly used to replace R22 and R502. It has the characteristics of clean, low toxicity, non-combustible, and good refrigeration effect. It is widely used in medium and low temperature refrigeration systems. Its ODP is 0, so R404A is a refrigerant that does not destroy the atmospheric ozone layer.
R410A
◆ R410A is mainly used to replace R22 and R502. It has the characteristics of clean, low toxicity, non-combustible, and good refrigeration effect. It is widely used in household air conditioners, small commercial air conditioners, and household central air conditioners.
The working pressure is about 1.6 times that of ordinary R22 air conditioner, and the cooling (heating) efficiency is high. R410A refrigerant consists of two quasi-azeotropic mixtures R32 and R125 each 50%, mainly composed of hydrogen, fluorine and carbon elements. R410A is now internationally recognized.
