Ammonia solution is used as working medium, in which ammonia is used as refrigerant and water is used as absorbent. The operating principle of the single-stage ammonia water absorption refrigerating machine is the same as that of the absorption refrigerating machine. According to the characteristics of the ammonia water solution, a rectifying tower and a condenser are installed on the upper part of the generator to improve the purity of the ammonia vapor. The evaporation temperature of single-stage ammonia water absorption refrigerators is generally about -30℃. Two-stage absorption (with two absorbers) has an even lower evaporation temperature of -60 ° C.
Ammonia water absorption chiller has been widely used in chemical industry because of its low evaporation temperature, which can be used in cold storage and industrial production. However, these refrigerators are bulky, use a lot of metal, and need to use steam at a higher pressure. And ammonia is toxic, corrosive to nonferrous metals, so the application is gradually reduced. An absorption-diffusion refrigerator is also used in domestic refrigerators, which also uses ammonia solution as the working medium, and filled with hydrogen to act as a pressure balance. The refrigerator can be heated by electricity or kerosene. It has no moving parts and is easy to use and noise-free.
