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Limiting Throttling Losses by Intracycle Evaporative Cooling.


pdf icon Limiting Throttling Losses by Intracycle Evaporative Cooling. (419 K)
Kim, B. S.; Domanski, P. A.

KSME-JSME Thermal Engineering, Third (3rd) Conference. Volume 3. October 20-23, 1996, Kyongju, Korea, 451-462 pp, 1996.

Sponsor:

Department of Energy, Washington, DC

Keywords:

cooling; evaporative cooling; simulation; test facilities; refrigeration

Abstract:

The temperature glide of zeotropic mixtures during phase change provides the opportunity to limit throttling losses of the refrigerant leaving the condenser. The difference between the intracycle evaporative cooling and the liquid-line/suction-line heat exchanger, instead of superheated vapor, is that a two-phase low-pressure refrigerant is used to subcool the high-pressure liquid leaving the condenser. The merits of the intracycle evaporative cooling were evaluated by a semi-theoretical simulation model and in the NIST's Small Breadboard 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(50/50), 3.6% for R407C, and 1.8% for R23/152a(20/80).