What are the classifications of air conditioning refrigerants

What are the classifications of air conditioning refrigerants

The refrigerants widely used in compression refrigerants are ammonia, freons and hydrocarbons.

　　 According to the chemical composition, refrigerants can be divided into five categories: inorganic compound refrigerants, freons, saturated hydrocarbon refrigerants, unsaturated hydrocarbon refrigerants and azeotropic refrigerants.

　　 According to the condensation pressure, refrigerants can be divided into three categories: high temperature (low pressure) refrigerants, medium temperature (medium pressure) refrigerants and low temperature (high pressure) refrigerants.

　　 Inorganic compound refrigerant: This type of refrigerant was used earlier, such as ammonia (NH3), water (H2O), air, carbon dioxide (CO2) and sulfur dioxide (SO2). For inorganic compound refrigerants, the internationally prescribed code is R and the following three digits, where the first digit is "7" and the last two digits are molecular weight. Such as water R718...etc.

　　 Freon (halocarbon refrigerant): Freon is a general term for derivatives of all or part of hydrogen (CL), fluorine (F) and bromine (Br) in saturated hydrocarbons. International regulations use "R" as the code name for this type of refrigerant, such as R22...etc.

　　 Saturated hydrocarbons: This type of refrigerant mainly includes methane, ethane, propane, butane and cyclic organic compounds. The code name uses "R" like Freon. This type of refrigerant is flammable and explosive, and has poor safety. Such as R50, R170, R290...etc.

Unsaturated hydrocarbon refrigerants: These refrigerants are mainly ethylene (C2H4), propylene (C3H6) and their halogen derivatives. The number after their R is mostly "1", such as R113, R1150. ..Wait.

Azeotropic mixture refrigerant: This type of refrigerant is an azeotropic mixture formed by mixing two or more different refrigerants in a certain ratio. This type of refrigerant can maintain a certain evaporation temperature under a certain pressure, and its gas or liquid phase is always Keep the composition ratio unchanged, but their thermodynamic properties are different from those before mixing. The use of azeotropic mixtures can improve the characteristics of refrigerants. Such as R500, R502...etc.

　　 High temperature, medium temperature and low temperature refrigerant: It is divided according to the standard evaporating temperature of the refrigerant and the condensation pressure at normal temperature.