Comparable Performance Evaluation of HC and HFC Refrigerants in an Optimized System.
Comparable Performance Evaluation of HC and HFC
Refrigerants in an Optimized System.
(277 K)
Domanski, P. A.; Yashar, D.
IIR Gustav Lorentzen Conference on Natural Working
Fluids, 7th. Proceedings. May 28-31, 2006, Tondheim,
Norway, 2006.
Keywords:
hydrocarbons; hydrofluorocarbons; evaluation;
refrigerants; isobutane; propane; compressing; comfort;
cooling; simulation; entropy; heat transfer
Abstract:
This paper presents an analytical evaluation of
isobutene (R600a), propane (R290), R134a, R22, R41OA,
and R32 in a vapor compression system used for comfort
cooling applications. The evaluation method was based on
a system simulation model that was complimented with
an evolutionary computation module for the optimization
of refrigerant circuitries in the evaporator and
condenser. The evaluation showed the coefficient of
performance (COP) for the studied refrigerants to be
within 13%, with R32 and R290 having the highest system
COPs. This evaluation produced a vastly different
ranking of the compared fluids than that obtained from a
theoretical cycle analysis based on thermodynamic
properties alone. In the system simulations, the high
pressure refrigerants overcame the thermodynamic
disadvantage associated with their low critical
temperature and had higher COPs than the low-pressure
R134a and R600a, which were ranked the highest by the
thermodynamic cycle analysis. The presented results
include entropy generation information for complete
systems and individual system components.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899