Various thermodynamic diagrams that are well known in absorption heat pump design and distillation techniques are introduced in this paper for nonazeotropic halogenated hydrocarbon mixtures. As an example, a typical compressor heat pump cycle for refrigerant mixtures is displayed and the cycle itself discussed using these diagrams.

It is shown that virtually all the necessary thermodynamic design information can be obtained from the enthalpy-composition diagram. It offers the possibility of determining the enthalpies, pressures, temperatures, and compositions involved by simple geometric constructions, even when the refrigerant flow rate varies in certain components.

Furthermore, it is shown by an example that thermodynamic diagrams provide a basic understanding of the influence of refrigerant properties on the heat pump cycle.