At present, there are dozens of types of substances that can be used as Fluorinated Solvent, but in the ordinary refrigeration range (-120~+5℃), there are only a dozen kinds of refrigerants used, and only refrigerants used in air-conditioning refrigeration systems There are several.

1. Freon

  Freon is a halogen derivative of saturated hydrogen hydrocarbon. According to the different atomic numbers of Freon chemical substances, there can be many types of Freon, and many codes can be compiled according to the prescribed numbering method. For example, the code name of Freon 22 is R22, and the code name of Freon 134a is R134a.

  Freon is an organic compound formed with the development of the organic chemical industry in the 1930s. It should be admitted that the emergence of many kinds of Freon has greatly improved the compressor refrigeration technology.

  Reminder: Freon is a substance harmful to the atmosphere. As the country pays more and more attention to the environment, as far as Beijing is concerned, the production, sales and use of R22 are all under monitoring.

2. Inorganic compounds

  Water and ammonia are the first two refrigerants using inorganic compounds. At present, ammonia is mainly used in large and medium-sized refrigeration warehouses and ice-making systems, while water is only used in lithium bromide absorption refrigeration devices. The code name for ammonia as a refrigerant is R717, and water is R718.

3. 
   Mixed refrigerant

  Mixed refrigerant is a mixture of two or more refrigerants mixed in a certain proportion. It can obtain better cycle performance than a single compound when it is produced at a certain interval of low temperature. Mixed refrigerants are divided into two types: azeotropic mixed refrigerants and non-azeotropic mixed refrigerants.

  Non-azeotropic mixed refrigerant: The refrigerant has an azeotropic point under a certain pressure. The temperature of the liquefaction or gasification process does not change under a certain pressure. Commonly used azeotropic mixed refrigerants are R502, R500, R410a and so on.

Heptafluoropropane HFC-227EA. This refrigerant has no azeotropic point under a certain pressure, and the temperature will change accordingly during the liquefaction or gasification process.

  Therefore, in the circulating refrigeration of the variable temperature heat source, the use of a non-azeotropic mixture can reduce the heat transfer temperature difference between the evaporator and the condenser, and improve the operating performance of the refrigeration device. Non-public boiling mixed refrigerants mainly include R12/R13, R22/R114, etc.