Experimental Evaluation of the Flammability and Performance Potentials of Two Azeotropic Refrigerant Mixtures.
Experimental Evaluation of the Flammability and
Performance Potentials of Two Azeotropic Refrigerant
Mixtures.
(3457 K)
Kim, M. S.; Mulroy, W. J.; Didion, D. A.
Korean Society of Mechanical Engineers. Symposium on
Transport Phenomena (ISTP-6) in Thermal Engineering, 6th
International. Volume 3. May 9-13, 1993, Seoul, Korea,
Lee, J. S.; Chung, S. H.; Kim, K. H., Editor(s)(s),
153-158 pp, 1993.
Keywords:
refrigerants; evaluation; flammability; heat pumps;
mixtures
Abstract:
The phaseout of CFC and HCFC refrigerants requies
determination of substitute refrigerants for use in
domestic heat pumps and refrigerators. This paper
presents both flammability and heat pump performance
test results of two azeotropic refrigerant mixtures of
R-134a (1,1,1,2-tetrafluoroethane) with R-290 (Propane)
and R-600a (Isobutane): R-290/134a (45/55), R-134a/600a
(80/20). The flammability limit of R-290/134a is found
as 2.9-11.0% by volume. And that of R-134a/600a is
3.9-13.3% by volume. Although the azeotropic mixtures
remain flammable, they are less than their pure
hydrocarbon components. The performance characteristics
are compared with pure R-12, R-22, R-134a, and R-290 at
test conditions including cases using
liquid-line/suction-line heat exchange. In most cases,
the coefficients of performance of the azeotropic
mixtures are higher than that of R-12 and R-134a. In
every case, the capacity for R-290/134a is higher than
that for R-22. Also, the system capacity for R-134a/600a
is higher than that for R-12 and R-134a. Results show
that the discharge temperature for the azeotropic
mixtures is always lower than that for the other
refrigerants.
