Abstract: Apparatus for protecting a liquid refrigerant pump from damage due to cavitation and loss of lubrication by inclusion of means for detecting the presence of vaporized refrigerant at the pump inlet and deactivating the pump in response thereto.

Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump is coupled to an outlet of the condenser for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.

Abstract: Liquid pressure amplification with Bypass is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, a pump, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.

Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling the an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump is coupled to an outlet of the condenser for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.

Abstract: This invention is a low pressure refrigeration or air-conditioning system comprising a compressor, a condenser and an evaporator interconnected in series in a closed loop for circulating refrigerant therethrough, and an improved subcircuit including a subcooler and centrifugal pump connected in series to recycle a portion of the liquid refrigerant from the condenser outlet back to the condenser inlet to desuperheat compressed refrigerant vapors. The subcooler receives a portion of the condensed liquid refrigerant from the outlet of the condenser at condenser outlet temperature and lowers that temperature by an increment of temperature, typically about 2.degree.-3.degree. F., to a temperature sufficiently lower than the condenser outlet temperature to prevent flashing of the refrigerant in the pump intake.

Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.

Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling the an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump, coupled to an outlet of the condenser, for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.

Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.

Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.

Abstract: A compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat by a centrifugal pump to a pressure sufficient to suppress flash gas in the conduit.