Minimizing Throttline Losses in the Refrigeration Cycle.
Minimizing Throttline Losses in the Refrigeration Cycle.
(4245 K)
Domanski, P. A.
International Congress of Refrigeration, 19th
Proceedings. Volume IVb. Theme 4. IIR Commission B2.
August 1995, Hague, The Netherlands, 766-773 pp, 1995.
Keywords:
refrigeration; air conditioning; economizer; ejector;
liquid-line/suction-line heat exchanger; Rankine cycle;
vapor compression cycle
Abstract:
Most alternative non-CFC refrigerants have a large
molecular structure and large heat capacity, which
influence the slope of saturated liquid line and result
in substantial throttling losses in a basic reversed
Rankine cycle. These losses degrade the cycle
efficiency below that of the original CFC fluids;
virtually all carbon-based non-hydrocarbon refrigerants
have a lower Coefficient of Performance than the fluids
banned by the Montreal Protocol. This study analyzes
the performance of pure-component refrigerants in the
basic refrigeration (reversed Rankine) cycle and in
three modified cycles in which the throttling-process
irreversibilities are minimized: the
liquid-line/suction-line heat exchange (llsl-hx) cycle,
the economizer cycle, and the ejector cycle. The
refrigerants considered in this study were the 38 fluids
covered by REFPROP /1/, and REFROP property routines
were employed in performance simulations. The
Carnahan-Starling-DeSantis equation of state was applied
for all fluids except ammonia, for which a formulation
by Harr and Gallagher was used.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899