A refrigeration system having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle.
BACKGROUND OF THE INVENTION
The present invention relates generally to refrigeration systems including air-conditioning systems utilizing a liquid over-feeding operation. More particularly, the present invention is directed to such refrigeration systems employing an accumulator-expander-heat exchanger containing capillary tubing through which hot, high-pressure liquid refrigerant from the condenser is passed in a heat exchange relationship with a pool of relatively cool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously expanding the liquid refrigerant and super sub-cooling the liquid refrigerant in the capillary tubing prior to the introduction of the super-cooled liquid refrigerant into the evaporator. This invention was made with the support of the United States Government under contract No. DE-AC05-84OR21400 awarded by the U.S. Department of Energy. The United States Government has certain rights in this invention.