Abstract: A vapor compression refrigeration system, such as a water chiller, uses a centrifugal compressor with magnetic bearings and a refrigerant, specifically HFC-227ea and HFC-227ca, to minimize enthalpy rise across the compressor and/or provide compression in a single stage for low cooling capacity. Magnetic bearings eliminate the problem caused by lubricated bearings to support rotating structure during normal compressor operation. The centrifugal compressor can be configured with a pre-defined static surge line.

Abstract: A portable, electrically powered refrigerant recovery system and method uses a single manifold to reduce fabrication time and costs. A hot gas discharge port in combination with a check valve allows the recovery system to be utilized as a vacuum pump as well as a refrigerant recovery device. A rectangular aluminum oil separator has internal baffles and is located between the inlet and a compressor. A low-voltage control circuit uses a latching circuit to avoid short cycling of the compressor and thereby increase compressor life. The system provides an improved push-pull recovery method in which superheated refrigerant vapor from the compressor is diverted directly to the system being recovered so that the superheated vapor is returned to the unit being emptied to speed the recovery process.

Abstract: A portable, electrically powered refrigerant recovery system and method uses a single manifold to reduce fabrication time and costs. A hot gas discharge port in combination with a check valve allows the recovery system to be utilized as a vacuum pump as well as a refrigerant recovery device. A rectangular aluminum oil separator has internal baffles and is located between the inlet and a compressor. A low-voltage control circuit uses a latching circuit to avoid short cycling of the compressor and thereby increase compressor life. The system provides an improved push-pull recovery method in which superheated refrigerant vapor from the compressor is diverted directly to the system being recovered so that the superheated vapor is returned to the unit being emptied to speed the recovery process.

Abstract: A heat pump system and method utilizes heat of mixing, in addition to the latent heat of solution, to increase cooling ability and thermal performance. The system includes a unique two-phase compressor for compressing a two-component mixture of liquid absorbent-refrigerant solution and superheated vapor to a high pressure. A generator extracts heat from the volume to be cooled by desorption and evaporation of the refrigerant from the high concentration solution in fluid connection with the inlet of the compressor. An absorber releases heat to surroundings by absorbing and condensing refrigerant vapor back into the liquid solution. A throttle valve controls the flow and reduces the pressure of the working fluid is in fluid connection with the absorber and the generator.

Abstract: A rotary compressor, such as a sliding vane compressor, comprises a housing having a bore, a rotor assembly operatively arranged to rotate within the bore, vanes operatively arranged at the rotor assembly to move linearly relative to the rotor assembly and to form, together with the housing and rotor assembly, variable chambers, and a valve assembly arranged in the housing. The bore has a configuration divided into a expansion region of elliptical shape, a circular transition region, a polynomial-shaped compression region and a circular sealing region. The lubricant seal is composed of an oil injection port and oil grooves for trapping and transporting the oil. The valve assembly is provided in a recess portion of the housing and is configured as a thin blade covering each discharge port which has been relieved to minimize undesirably large difference of the pressure forces between the two sides of the blade. Oil grooves are provided in the rotor assembly and in end cap assemblies.