A heat pump system includes a refrigerant circuit that has a compressor, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, a modulating valve, and a reversing valve. The reversing valve is configured to transition between a first configuration to direct refrigerant from the compressor toward the modulating valve and a second configuration to direct the refrigerant from the compressor toward the first heat exchanger. The heat pump system also includes control circuitry configured to concurrently maintain the reversing valve in the first configuration and adjust a position of the modulating valve to direct a first portion of the refrigerant from the modulating valve to the second heat exchanger and a second portion of the refrigerant from the modulating valve to the reheat heat exchanger based on an operating mode of the heat pump system.

A fluid pump for pumping a fluid. One or more piston-cylinder arrangements each include a respective cylinder portion, a respective head portion and a respective piston portion together defining a respective pumping chamber. One or more connecting arrangements connect a crank member to the one or more piston-cylinder arrangements to drive the respective piston portion of each of the one or more piston-cylinder arrangements. A housing and the respective piston portion of each of the one or more piston-cylinder arrangements together house the crank member in an interior. The interior is sealed to capture blow-by. A transmission is arranged to transmit power, for rotating the crank member, into the housing magnetically, electrically or both.

A system and method for dual compressor modulation by controlling a flow of refrigerant in a reversing valve. A method includes receiving, by a control board, a command for operating a reversing valve in different modes. The reversing valve includes a first tube, a second tube, a third tube, a fourth tube and a fifth tube. The method includes determining a position for operating the reversing valve in a first position or a second position in a first mode and in a third position or a fourth position in a second mode. The method includes controlling a flow of refrigerant based on the command and the position by connecting the fourth tube with a first compressor in the first/third position and connecting the fifth tube with a second compressor in the second/fourth position.

A heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger, a mode switching valve, a throttling element and a reservoir, wherein the throttling element is arranged on a flow path between the first heat exchanger and the second heat exchanger; and which further comprises a mode switching flow path in which a first flow path and a second flow path are arranged, the reservoir is arranged on the second flow path and each flow path is controllably opened or closed to realize different functional modes.

A cryocooler includes a displacer, a cylinder that forms an expansion space, a Scotch yoke mechanism configured to drive the displacer in a reciprocating manner, a first rod that extends from the Scotch yoke mechanism, a housing that includes an assist chamber, a rotary valve configured to switch between a state in which the expansion space and a discharge side of a compressor are connected and the assist chamber and a suction side of the compressor are connected and a state in which the expansion space and the suction side of the compressor are connected and the assist chamber and the discharge side of the compressor are connected, a motor configured to drive the Scotch yoke mechanism and the rotary valve, and an on-off valve configured to open and close a gas flow path through which the rotary valve and the assist chamber are connected.

When the temperatures of outdoor heat exchangers 23a and 23b detected by outdoor heat exchanger temperature sensors 57a and 57b become equal to or higher than 5 degrees C. and the sucking superheating degrees of compressors 21a and 21b become equal to or lower than 0 degrees C. while an air conditioning apparatus 1 is performing the reverse defrosting operation, the reverse defrosting operation is stopped and the heating dominant operation is resumed. At this time, the total operating times of the compressors 21a and 21b are reset. The sucking superheating degrees of the compressors 21a and 21b are obtained by subtracting the low pressure saturation temperatures calculated from the sucking pressures of the compressors 21a and 21b, from the temperatures of the refrigerants sucked into the compressors 21a and 21b which temperatures are detected by the sucking temperature sensors 54a and 54b.

An air conditioning apparatus includes: an outdoor unit configured to circulated refrigerant; a first pipe and a second pipe that are connected to the outdoor unit; an indoor unit configured to circulate water; and a heat exchange device that connects the outdoor unit to the indoor unit. The heat exchange device includes a first heat exchanger and a second heat exchanger that are each configured to perform heat exchange between the refrigerant and the water, a plurality of connection pipes, a bypass pipe configured to guide the refrigerant passing through the first heat exchanger to the second heat exchanger, and a bypass valve installed at the bypass pipe.

A two-pipe enhanced-vapor-injection outdoor unit and a two-pipe enhanced-vapor-injection multi-split system are provided. The two-pipe enhanced-vapor-injection outdoor unit includes an outdoor heat exchanger, an enhanced-vapor-injection compressor, a reversing assembly, a super cooler, a throttling assembly and a first pipe. The reversing assembly includes a first end and a second end connected with a gas discharge port and a gas return port, respectively. A main heat-exchange flow path is connected with the first port and the second port, respectively. An auxiliary heat-exchange flow path is connected with the injection port. The throttling assembly includes two ends connected with an outlet of the main heat-exchange flow path and an inlet of the outdoor heat exchanger. The first pipe includes a first end connected with an outlet of the outdoor heat exchanger, and a second end arranged between the throttling assembly and the main heat-exchange flow path.

A refrigeration apparatus (1) includes a heat-source-side unit (10) using a refrigerant that works in a supercritical region. The heat-source-side unit (10) includes a compression element (20) configured to compress the refrigerant, a heat-source-side heat exchanger (24), an expansion valve (26) provided downstream of the heat-source-side heat exchanger (24), a receiver (25) provided downstream of the expansion valve (26), and a control unit (101). The control unit (101) performs a first operation for evaluating the amount of the refrigerant based on a high-pressure-side pressure, on a first condition that the internal pressure of the receiver (25) be equal to or less than a supercritical pressure.

A liquid slug reduction and charge compensator device for use in air conditioning and heat pump systems includes a housing having a cavity. The housing includes an inlet port providing an entry path into the cavity and an outlet port providing an exit path from the cavity. The housing further includes a liquid line port providing a refrigerant pathway into and out of the cavity. The liquid slug reduction and charge compensator device further comprises a flash tube extending through the cavity and providing a passageway through the cavity such that a hot gas refrigerant that enters the cavity through the inlet port causes a liquid refrigerant that enters the flash tube to evaporate.