Performance of HC and HFC Refrigerants in a Finned-Tube Evaporator and Its Effect on System Efficiency.
Performance of HC and HFC Refrigerants in a Finned-Tube
Evaporator and Its Effect on System Efficiency.
(103 K)
Domanski, P. A.; Yashar, D. A.; Kim, M. S.
Natural Working Fluids Conference, 6th IIR Gustave
Lorentzen. Proceedings. August 29-September 1, 2004,
Glasgow, UK, 1-8 pp, 2004.
International Journal of Refrigeration, Vol. 28, No. 6,
820-827, September 2005.
Keywords:
refrigerants; tubes; efficiency; evaporator
Abstract:
The paper presents a comparable evaluation of isobutane
(R600a), propane (R290), R134a, R22, R410A, and R32 in
an optimized finned-tube evaporator, and analyzes the
impact of evaporator effects on the system coefficient
of performance (COP). The study relied on a detailed
evaporator model derived from NIST's EVAP-COND
simulation package and used the ISHED1 scheme employing
a non-Darwinian Learnable Evolution Model for circuitry
optimization. In the process, 4500 circuitry designs
were generated and evaluated for each refrigerant. The
obtained evaporator optimization results were
incorporated in a conventional analysis of the vapor
compression cycle. For a theoretical cycle analysis
without accounting for evaporator effects, the COP
spread for the studied refrigerants was as high as
11.7%. For cycle simulations including evaporator
effects, the COP of R290 was better than that of R22 by
up to 3.5%, while the remaining refrigerants performed
within approximately a 2% COP band of the R22 baseline
for the two condensing temperatures considered.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899