Performance Evaluation of Two Azeotropic Refrigerant Mixtures of HFC-134a With R-290 (Propane) and R-600a (Isobutane).
Performance Evaluation of Two Azeotropic Refrigerant
Mixtures of HFC-134a With R-290 (Propane) and R-600a
(Isobutane).
(645 K)
Kim, M. S.; Mulroy, W. J.; Didion, D. A.
ASME Journal of Energy Resources Technology, Vol. 116,
148-154, June 1994.
Keywords:
refrigerants; evaluation; flammability measurements;
heat pumps; evaluation; thermodynamic properties; high
temperature; cooling; heating; simulation; heat transfer
Abstract:
The reduction in chlorofluorocarbon (CFC) and
hydrochlorofluorocarbon (HCFC) production and the
scheduled phase-out of these ozone-depleting
refrigerants require the development and determination
of environmentally safe refrigerants for use in heat
pumps, water chillers, air conditioners, and
refrigerators. This paper presents a performance
evaluation of a generic heat pump with two azeotropic
refrigerant mixtures of HFC-134a
(1,1,1,2-tetrafluoroethane) with R-290 (propane) and
R-600a (isobutane); R-290/134a (45/55 by mass
percentage) and R-134a/600a (80/20 by mass percentage).
The performance characteristics of the azeotropes were
compared with pure CFC-12, HFC-134a, HCFC-22, and R-290
at the high temperature cooling and heating conditions
including those using liquid-line/suction-line heat
exchange. The coefficient of performance of R-290/134a
is lower than that of HCFC-22 and R-290, and R-134a/600a
shows higher coefficient of performance than CFC-12 and
HFC-134a. The capacity for R-290/134a is higher than
that for HCFC-22 and R-290, and R-134a/600a exhibits
higher system capacity than CFC-12 and HFC-134a.
Experimental results show that the discharge
temperatures of the studied azeotropic mixtures are
lower than those of the pure refrigerants, CFC-12 and
HCFC-22.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899