In order to master the relevant knowledge of the chiller , naturally it is necessary to understand the relevant principles of the chiller, and as an important material for cooling the chiller, the "refrigerant" has to be understood accordingly, and the refrigerants in the refrigeration system are generally Difluoromonochloromethane (chemical name), the role and classification of refrigerant R22 are introduced below.
Chemical name: Difluoromonochloromethane
CAS number: 75-45-6
Molecular formula: CHCLF2
Molecular weight: 86.47
Boiling point: -40.8 ℃
Relative density (30 ° C), liquid, 1.174 g / cm3
Melting point: -160.00 ℃
Critical temperature: 96.2 ℃
Critical pressure 4.99 MPA
Ozone Destruction Potential (ODP) 0.055
Global warming coefficient (GWP) 0.36
Specific heat of liquid 30 ℃, [KJ / (Kg • ℃)] 0.31
Saturated liquid density 30 ℃, (g / cm3) 1.174
Specific pressure vapor specific heat (Cp), 30 ℃ and 101.3kPa [KJ / (Kg • ℃)] 0.16
Critical density, g / cm3 0.526
Evaporation potential at boiling point, KJ / Kg 233.5
R22 has better stability to metals and no corrosion. However, when R22 contains water, copper plating is liable to occur. R22 has a certain aggressiveness to natural rubber and plastic organic materials. Chloroethanol rubber can be used.
Technical index of refrigerant R22:
| Indicator name || Top grade || First grade || Qualified product |
| Exterior || Colorless and turbid |
| odor || No peculiar smell |
| Purity,%, ≥ || 99.8 || 99.5 || 99.0 |
| Moisture,%, ≤ || 0.001 || 0.002 || 0.005 |
| Acidity (as HCI),%, ≤ || 0.00001 || 0.0001 || 0.0001 |
| Evaporation residue,% ≤ || 0.01 || 0.01 || 0.02 |
R22 is mainly used for reciprocating compressors, as refrigerants in industrial, commercial, and household air-conditioning systems; it can also be used as aerosol sprays and spray aerosol sprays; it can also be used to produce fire extinguishing agents 1211; Basic raw materials for fluoropolymers. R22 is a HCFC refrigerant. According to the Montreal Protocol, it will be phased out by 2020.
Main environmental alternatives: R404A, R410A
Major manufacturers: Domestic manufacturers mainly include Luzhou Juhua Group, Shandong Dongyue Group, Zhejiang Meilan Chemical, Sanaifu and other major international brands: DuPont, Honeywell, Arkema, etc. However, because developed countries have eliminated R22 in advance, and they are not allowed to produce this product in their home countries, the so-called imported R22 sold in the market is actually domestic OEM production, which is generally used for air-conditioning or dual-machine cascades. The high-temperature end refrigerant is stronger than normal refrigerants.
R22 belongs to the classification: R22 is a member of the Freon family and belongs to the hydrochlorofluorocarbons. Definition of Freon. Freon is a general term for halogenated derivatives of saturated hydrocarbons (hydrocarbons). It is a type of refrigerant that emerged with the development of the chemical industry in the 1930s. The air-conditioning industry's search for refrigerants. It can be seen from the definition of Freon that the non-Freon R134a, R410A, and R407C that are now called are actually Freon. Freon can destroy the ozone layer because of the presence of CL in the refrigerant, and as the number of CL atoms increases, the ability to destroy the ozone layer increases, and as the content of H elements increases, the ability to destroy the ozone layer decreases; the main cause of the greenhouse effect is During the slow oxidative decomposition of the refrigerant, a large amount of greenhouse gases such as CO2 are generated. According to the molecular structure of Freon refrigerants, it can be roughly divided into the following three categories:
1. Chlorofluorocarbons: abbreviated as CFC, mainly including R11, R12, R113, R114, R115, R500, R502, etc., because of its damaging effect on the ozone layer and the largest, it is listed as a controlled substance under the Montreal Protocol Such substances are currently banned, and R141b has been used as a transitional replacement for R11 in the manufacture of polyurethane sponges.
2. Hydrochlorofluorocarbons: HCFC for short, mainly including R22, R123, R141b, R142b, etc. The ozone destruction factor is only a few percent of R11. Therefore, HCFCs are currently regarded as the most important transition for CFCs Sexual substitutes. In the Montreal Protocol, R22 is restricted to be eliminated in 2020 and R123 is restricted to 2030. Developing countries can postpone it for 10 years.
3. Hydrofluorocarbons: abbreviated to HFC, mainly including R134a, R125, R32, R407C, R410A, R152, etc., the ozone layer destruction coefficient is 0, but the climate warming potential is very high. The Montreal Protocol does not stipulate its life span, and it is characterized as a greenhouse gas in the Kyoto Protocol to the United Nations Framework Convention on Climate Change.
All the refrigerants currently used by Dongguan Guansheng Machinery Co., Ltd. are all Freon products. Non-Freon refrigerants have not been developed so far. Before the development of new refrigerants, what we have to solve is the kind of refrigerants that air-conditioning units use, which will cause less damage to the environment on which we depend. We should expressly prohibit the use of Class 1 products, not Class 2 and Class 3 refrigerants.