Halocarbon Refrigerants:
The halocarbon refrigerants are produced through replacing one or more of hydrogen atoms of ethane or methane by one or more atoms of the three halogens: chlorine, fluorine or bromine. Some refrigerants coming under this category are described below:
Refrigerant R12
The refrigerant R12 is the most broadly utilized refrigerant in the large and domestic commercial establishments. Its chemical formula is CCl2F2 and its boiling pt is -300C at 1 bar. This is a non-explosive, non-flammable, non-toxic, non-irritating, and odourless refrigerant. It remains chemically constant up to 5500C. Also, this does not influenced the material of the refrigeration system. This is available in abundance and it is quite cheap. But, its use is being discontinued today for its contribution to ozone layer depletion.
Refrigerant R13
Its chemical formula is CClF3. this is a non-toxic, non-flammable and stable refrigerant. This is very appropriate for attaining low temperatures in a cascade refrigeration system. Its specific volume is high and thus, it is appropriate for centrifugal compressors. But, it also contains a negative effect on ozone depletion.
Refrigerant R22
Its chemical formula is CHClF2. this is also a non-flammable, non-toxic non-corrosive and non-irritating refrigerant. This is the most common refrigerant for utilize in large refrigeration systems and it is preferred over R12.
Refrigerant R114
Its chemical formula is C2Cl2F4. Its boiling point equivalent to 1 bar is approximate 30C. It contains properties very same to those of R12 w. r. t. water & oil combination. This is not appropriate for low temperature refrigeration as this has negative evaporator pressure even at approximate 9 0C. This is non-explosive, non-toxic and non-corrosive even in the presence of water.