What types of environmentally friendly refrigerants are currently in use (classification)

The refrigerants widely used in compressed refrigerants are ammonia, Freon and hydrocarbons. According to their chemical composition, refrigerants can be divided into five categories: inorganic compound refrigerants, Freon, saturated hydrocarbon refrigerants, unsaturated hydrocarbon refrigerants and azeotropic mixture refrigerants. According to the condensing pressure, refrigerants can be divided into three categories: high temperature (low pressure) refrigerants, medium temperature (medium pressure) refrigerants and low temperature (high pressure) refrigerants.

The commonly used Freon refrigerants are R12, R22, R502 and R1341a, as other models are now discontinued or banned. They are not described here

Freon 12 (CF2CL2, R12): It is one of the more widely used Freon refrigerants, mainly used in medium and small food banks, domestic refrigerators and water and road refrigerated transport refrigeration devices. R12 is a medium temperature refrigerant and can be used in small and medium-sized piston compressors to obtain a low temperature of -70℃. And for large centrifugal compressor can get -80℃ low temperature. In recent years, the refrigerant used in refrigerators is R134a.

Freon 22 (CHF2CL, R22): one of the more widely used Freon refrigerants, mainly used in domestic air-conditioners and low-temperature refrigerators. The standard gasification temperature is -40.8°C and the condensing pressure usually does not exceed 1.6 MPa. R22 is non-flammable, non-explosive and safer than ammonia in use. In recent years, the refrigerant of large air-conditioning chillers is mostly used instead of R134a.

Freon 502 (R502): R502 is an azeotropic solution consisting of R12 and R22 mixed in percentages of 51.2% and 48.8%.R502 has better thermodynamic properties compared to R115 and R22 and is more suitable for low temperatures.The standard evaporation temperature of R502 is -45.6°C and the normal working pressure is similar to that of R22. R502 is used in fully enclosed, semi-enclosed or certain medium or small refrigeration units, where the evaporation temperature can be as low as -55°C. R502 is used more often in refrigerated cabinets.

Freon 134a (C2H2F4, R134a): is a relatively new refrigerant with an evaporation temperature of -26.5°C. Its main thermodynamic properties are similar to R12, it does not destroy the ozone layer in the air and is an environmentally friendly refrigerant advocated in recent years, but it causes a greenhouse effect. It is a more ideal replacement refrigerant for R12. Environmentally friendly refrigerants, generally the following* R-134a (tetrafluoroethane) refrigerant R134a is currently internationally recognised as one of the main refrigeration refrigerants replacing R12 and is commonly used in automotive air conditioning, commercial and industrial refrigeration systems, and as a blowing agent in the production of hard plastic insulation materials, and can also be used to configure other refrigerant blends such as R404A and R407C. Main applications: Mainly used as a refrigerant instead of R12, used in large quantities in automotive air-conditioning and refrigerator refrigeration. Packaging: in cylinders, 13.6kg/bottle, 400kg/bottle, 1000kg/bottle, ISO TANK* R-410A refrigerant Physical and chemical properties: At room temperature and pressure, R410A is a chlorine-free, non-azeotropic refrigerant blend of fluorinated alkanes, colourless gas, stored in cylinders as a compressed, liquefied gas.