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The Influence of the Thermophysical Fluid Properties of the New Ozone-Safe Refrigerants on Performance



David Didion


The selection a working fluid as a refrigerant for the vapor compression cycle is discussed. For thermodynamic performance to be optimized particular attention must be paid to the fluid's critical point and molar heat capacity. To achieve a reasonable balance between volumetric capacity, which implies equipment size, and coefficient of performance, which is efficiency, it is necessary to select a fluid with a critical point such that the application's condenser will operate in a reduced temperature range of approximately 0.7 to 0.9. It is also necessary to select fluids within a rather limited range of molar heat capacity values. The specifics as to how these properties affect the cycle's performance are presented in detail. For a better matching of the working fluid to a given application, both azeotropic and zeotropic mixtures of fluids are used. The characteristics and performance advantages and disadvantages of these mixtures are discussed.
International Journal of Applied Thermodynamics
No. 1


azeotropic mixtures, refrigerants, thermophysical properties, two-phase flow, vapor compression


Didion, D. (1999), The Influence of the Thermophysical Fluid Properties of the New Ozone-Safe Refrigerants on Performance, International Journal of Applied Thermodynamics, [online], (Accessed June 24, 2024)


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Created March 1, 1999, Updated February 19, 2017