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 includes 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.

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.

An air conditioning system, including a compressor, two outdoor heat exchange units, a liquid pipe used for communicating with indoor units, a high-pressure gas tube and a low-pressure gas tube; the air conditioning system further includes a valve assembly. One outdoor heat exchange unit has a first state in which one end thereof communicates with the high-pressure gas tube and another end thereof communicates with the liquid pipe, and has a second state in which one end thereof communicates with the low-pressure gas tube and the other end thereof communicates with the liquid pipe. Further disclosed is a control method for the air conditioning system.

A motor is provided in a shell. The motor includes a stator having an outer peripheral surface facing an inner peripheral surface of the shell, a rotor rotatably disposed inside the stator, and a nonmagnetic film disposed between the outer peripheral surface of the stator and the inner peripheral surface of the shell.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

A heating and cooling system includes a reversing valve configured to adjust a flow of refrigerant through the heating and cooling system, where the reversing valve includes a first configuration to flow the refrigerant through a first circuit of the heating and cooling system and a second configuration to flow the refrigerant through a second circuit of the heating and cooling system. The heating and cooling system also includes a controller configured to determine an operating parameter of a compressor of the heating and cooling system, where the controller is configured to adjust operation of the compressor based on the operating parameter to adjust a position of the reversing valve.

Modular heating and cooling systems may include one or more modules connected to a fluid input and fluid output. A modular heating system includes at least one heating and cooling apparatus. The apparatus includes a first heat exchanger, a second heat exchanger and a third heat exchanger. The apparatus further includes a refrigerant line system coupled to the first (e.g. cooling), second (e.g. heating) and third (e.g. source) heat exchangers and configurable for selectively directing refrigerant fluid through the heat exchanger to provide multiple modes of operation. The heating, cooling and source fluid loops may be separate and independent such that the fluids do not mix.

Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.

Various embodiments of a heat pump system are disclosed to provide improved and flexible heat pump operation when dehumidification of the conditioned space is required. In one embodiment, a heat pump system includes a heat pump loop comprising a refrigerant circuit that fluidly interconnects (1) a compressor; (2) a source heat exchanger; (3) a source heat exchanger bypass circuit comprising a bypass valve; (4) a space heat exchanger; (5) a reversing valve positioned on the discharge side of the compressor; (6) a reheat circuit comprising a reheat heat exchanger; (7) first and second expansion devices; and (8) first and second expansion device bypass circuits configured to allow refrigerant to bypass the first and second expansion devices, respectively, where the first and second bypass circuits include first and second check valves, respectively; and (9) a 3-way valve configured to selectively direct refrigerant flow to the first expansion device, the reheat circuit, and the second expansion device.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and a valve coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine that the outdoor heat pump unit is in operation during an air conditioning cycle. The controllers are further operable to determine an outdoor temperature and compare the outdoor temperature to a predetermined temperature. The controllers are further operable to initiate a closure of the valve coupled to the refrigerant line and initiate operation of the compressor at an end of the air conditioning cycle to pump down a refrigerant to the outdoor coil in response to comparing the outdoor temperature to the predetermined temperature.