Equation-of-State-Based Thermodynamic Charges for Nonazeotropic Refrigerant Mixtures.
Equation-of-State-Based Thermodynamic Charges for
Nonazeotropic Refrigerant Mixtures.
(3348 K)
Domanski, P. A.; Didion, D. A.
CH-85-05 No. 2;
ASHRAE Transactios, Vol. 91, No. 1, 1985.
Keywords:
refrigerants; mixtures; equations; themodynamics;
enthalpy; entropy; machinery; algorithms; thermodynamic
properies
Abstract:
Application of a nonazeotropic mixture to a
refrigeration machine offers a new degree of freedom in
controlling machine performance by control of
circulating mixture composition. Presenting possible
thermodynamic cycles of such a machine operating with
different mixture compositions requires developing
appropriate thermodynamic charts with refrigerant
mixture composition as a variable. This paper presents
thermodynamic charts developed for a nonazeotropic
mixture, R13B 1/R152a. The developed charts
(pressure-enthalpy, temperature-entropy, and enthalpy
composition), though for sake of clarity showing limited
data, offer important insight for understanding vapor
compression cycles for different compositions. An
equation of state capable of describing both the liquid
and vapor phases, property algorithms and iteration
schemes used in determination ofthe nonazeotropic
mixture thermodynamic properties have been explained.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899