- Author
-
Didion, D. A.
|
Bivens, D. B.
- Title
- Role of Refrigerant Mixtures as Alternatives to CFCs.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
-
International Journal of Refrigeration,
Vol. 13,
163-175,
May 1990
- Keywords
-
refrigerants
|
alternative refrigerants
|
refrigerant mixtures
|
azeotropes
|
near-azeotropes
|
zeotropes
- Abstract
- Regrigerant mixtures may provide some solutions to the problem of the very limited number of fluids which have suitable properties to provide alternatives to CFCs. Mixing of refrigerants allows the adjustment or tuning of the most desirable properties of the mixture by varying the molar fraction of the components. There are three categories of mixtures which can be used as working fluids: azeotropes, near-azeotropes and zeotropes. Azeotropes are usually binary and have long been used in the refrigeration industry; it is unlikely that new combinations will now be found. Near-azeotropes have a much greater potential for development, but under leakage conditions may alter their composition and properties. Near-azeotropes have the most potential as drop-in alternative to CFCs. Aeotropes have potential for improvements in energy efficiency and capacity modulation, but, as they require hardware design changes can only be considered in new system designs. However, with the long-term concerns about global warming, energy efficiency, and therefore the use of zeotropes will probably have a great influence on the refrigeration industry.