Types and Selection of Air Conditioner Refrigerants

Friends who use air conditioners all know that whether it is a central air conditioner or a household air conditioner, it is necessary to add refrigerant, which is a very important material in the accessories of the central air conditioner. Let’s take a look at the types of air conditioner refrigerants and the problem of choosing refrigerants for your air conditioner.

At present, there are dozens of types of substances that can be used for refrigeration. But in the ordinary refrigeration range (-120~+5℃), only a dozen refrigerants are used. There are only a few refrigerants used in air conditioning refrigeration systems.

1. Freon

Freons are halogen derivatives of saturated hydrogen hydrocarbons. There can be many kinds of Freon, depending on the number of atoms in the Freon chemical. According to the prescribed numbering method, many codes can be programmed, 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 acknowledged that the emergence of a variety of Freons has greatly improved compressor refrigeration technology.

In addition, Freon is a harmful substance to the atmosphere. As the world pays more and more attention to the environment, the production, sales, and use of R22 are all under monitoring.

2. Inorganic Compounds

Water and ammonia were the first two refrigerants to use inorganic compounds. At present, ammonia is mainly used in large and medium-sized refrigerators and ice-making systems, while water is only used in lithium bromide absorption refrigeration units. The code name of ammonia as refrigerant is R717, and the water is R718.

3. Blended Refrigerant

A blended refrigerant is a mixture of two or more refrigerants mixed in a certain proportion. When it is prepared at a low temperature in a certain range, it can obtain better cycle performance than a single compound. Mixed refrigerants are divided into 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, etc.

Non-azeotropic refrigerant mixture. Under certain pressure, this refrigerant has no azeotropic point, and the temperature will change accordingly during the liquefaction or gasification process.

Therefore, in the cycle refrigeration of the variable temperature heat source, the use of the non-azeotropic mixture formulation can reduce the heat transfer temperature difference between the evaporator and the condenser, and improve the operational performance of the refrigeration device. There are mainly R12, R13, R22, R114, etc.