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


pdf icon Influence of the Thermophysical Fluid Properties of the New Ozone-Safe Refrigerants on Performance. (1546 K)
Didion, D. A.

International Journal of Applied Thermodynamics, Vol. 2, No. 1, 19-35, March 1999.

Keywords:

refrigerants; ozone; azeotropic mixtures; thermophysical properties; two-phase flow; vapor compression cycle; zeotropic

Abstract:

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 effect the cycle's performance are presented in detail. For a better matching of the working fluid to a given application, both azeotopic and zeotropic mixtures of fluids are used. The characteristics and performance advantages and disadvantages of these mixtures are discussed.