What Are The Introductions To Freon

Freon-12
(Code: R12)
R12 is a halogenated compound of alkanes, scientific name difluorodichloromethane, and molecular formula CF2Cl2. It is a medium pressure medium temperature refrigerant widely used in small and medium-sized refrigeration devices in China. The standard evaporation temperature of R12 is -29.8 ℃, the condensation pressure is generally 0.78-0.98 MPa, the solidification temperature is -155 ℃, and the standard cooling capacity per unit volume is about 288 kcal/m3.
R12 is a colorless, transparent, odorless, almost non-toxic, non flammable, non explosive, and very safe refrigerant. Only when the volume concentration in the air exceeds 80% can it cause suffocation. But when in contact with open flames or at temperatures above 400 ℃, it decomposes into gases that are harmful to the human body.
R12 can be miscible with any proportion of lubricating oil and can dissolve various organic substances, but its water absorption is extremely weak. Therefore, in small Freon refrigeration devices, there is no oil separator, but a dryer is installed. At the same time, it is stipulated that the water content in R12 should not exceed 0.0025%, and general natural rubber should not be used as sealing gaskets in the system. Instead, artificial rubber such as nitrile rubber or chloroethanol should be used. Otherwise, it will cause the expansion of the sealing gasket and cause refrigerant leakage.
Freon-22
(Code: R22)
R22 is also a halogenated compound of alkanes, scientific name difluoromethane, molecular formula CHClF2, standard evaporation temperature is about -41 ℃, solidification temperature is about -160 ℃, condensation pressure is similar to ammonia, and standard refrigeration capacity per unit volume is about 454 kcal/m3.
R22 has many properties similar to R12, but its chemical stability is not as good as R12, and its toxicity is slightly higher than R12. However, the refrigeration capacity per unit volume of R22 is much larger than R12, close to ammonia. When a low temperature of -40~-70 ℃ is required, R22 is more suitable than R12. Therefore, at the time of publication, R22 is widely used in two-stage compression or air conditioning refrigeration systems of -40~-60 ℃.