Conclusion
Thermodynamic charts - Mixtures used in thermal machines

This article introduces the study of thermodynamic fluid mixtures, discusses temperature-slip refrigerant diagrams and presents the diagrams used to analyze absorption cycles, which are variable-composition mixtures of a sorbent and a refrigerant.

Three examples of temperature-slip mixture diagrams are given. They relate to refrigeration, heat pump and organic Rankine cycles, and show that the choice of using a mixture rather than a pure fluid can have a significant impact on the performance of the thermodynamic cycle under consideration. However, there is no general answer: everything depends on the possible pinches that constrain heat exchanges, particularly with external sources.

An ammonia absorption machine cycle has been calculated in detail and represented in two types of diagrams: Merkel and Oldham.

The article...