Intracycle Evaporative Cooling in a Vapor Compression Cycle.
Intracycle Evaporative Cooling in a Vapor Compression
Cycle.
(937 K)
Kim, B. S.; Domanski, P. A.
NISTIR 5873; 25 p. September 1996.
Sponsor:
Department of Energy, Washington, DC
Available from:
National Technical Information Service
Order number: PB97-116107
Keywords:
cooling; air conditioning; building technology;
coefficient of performance; heat pumps; refrigeration;
zeotropic mixtures
Abstract:
The temperature glide of zeotropic mixtures during phase
change provides the opportunity to limit throttling
losses of the refrigeration cycle by intracycle
evaporative cooling of the refrigerant leaving the
condenser. Intracycle evaporative cooling is similar to
the use of a liquid-line/suction-line heat exchanger
with the difference that a two-phase low-pressure
refrigerant, instead of superheated vapor, is used to
subcool the high-pressure liquid leaving the condenser.
Intracycle evaporative cooling was evaluated by a
semi-theoretical simulation model and experimentally in
an instrumented laboratory heat pump at the cooling mode
operating condition typical for a water-to-water
residential heat pump. The capacity, coefficient of
performance (COP), pressures, and temperature profiles
of refrigerant and heat-transfer fluid in the heat
exchangers are reported. The laboratory measured
improvement of the COP was 4.0% for R32/152a, 3.6% for
R407C, and 1.8% for R23/152a.
