Study to Determine the Existence of An Azeotropic R-22 "Drop-In" Substitute.
Study to Determine the Existence of An Azeotropic R-22
Kim, M. S.; Morrison, G.; Mulroy, W. J.; Didion, D. A.
NISTIR 5784; 48 p. March 1996.
Sponsor:Electric Power Research Institute, Palo Alto, CA
Available from: National Technical Information Service
Order number: PB96-167812
azeotropic refrigerant mixtures; air conditioning; heat
pumps; alternative refrigerants; refrigeration; working
fluids; HFC-134a; propane; cyclopropane; isobutane
The reduction in chlorofluorocarbon (CFC) and
hydrochlorofluorocarbon (HCFC) production and the
scheduled phase-out of these ozone depleting
refrigerants requires the development and determination
of environmentally safe refrigerants for use in heat
pumps, water chillers, air conditioners and
refrigerators. Azeotropic mixtures are attractive as
alternative refrigerants because they behave very nearly
as pure materials. A simple correlation scheme that
allows one to judge whether or not an azeotrope is
likely in a binary refrigerant mixture is discussed.
This paper presents laboratory and computer simulation
evaluation of two of the azeotropic refrigerant mixtures
which were identified, HFC-134a
(1,1,1,2-tetrafluoroethane) with R-290 (Propane) and
HFC-134a with R-600a (isobutane), in a generic heat pump
apparatus. A third azeotropic mixture, HFC-134a with
R-C290 (Cyclopropane) is examined by computer simulation
only. The performance characteristics of these
azeotropes were compared with pure CFC-12, HFC-134a,
HCFC-22, and R-290 at high temperature cooling and
heating conditions. Use of liquid-line/suction-line
heat exchange was evaluated.