2. Thermodynamic diagrams of the ammonia-water mixture

Compared with the water-lithium bromide pair presented in the article [BE 9 735] , the ammonia-water pair is distinguished by the presence of water (the sorbent) in the ammonia vapour (the refrigerant) desorbed by the liquid solution. This fact is clearly illustrated by the Oldham and Merckel diagrams, which we'll now present and explain how to use. The presence of water in the refrigerant also implies more complex unit operations, in particular evaporation, with a temperature shift that can be significant depending on the composition of the refrigerant, and an additional operation, vapour rectification....