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.

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.

An HVAC system is disclosed, comprising: (a) a compressor, (b) a source heat exchanger for exchanging heat with a source fluid, (c) a first load heat exchanger operable for heating/cooling air in a space, (d) a second load heat exchanger for heating water, (e) first and second reversing valves, (f) first and second 3-way valves, (f) a bi-directional electronic expansion valve, (g) a first bi-directional valve, and (h) a second bi-directional valve to modulate exchange of heat in the first load heat exchanger when operating as an evaporator and to control flashing of the refrigerant entering the source heat exchanger when operating as an evaporator, (h) a source pump for circulating the source fluid through the first load heat exchanger, (i) a water pump for circulating water through the second load heat exchanger, and (j) a controller to control operation of the foregoing.

An HVAC system is disclosed, comprising: (a) a compressor, (b) a source heat exchanger for exchanging heat with a source fluid, (c) a first load heat exchanger operable for heating/cooling air in a space, (d) a second load heat exchanger for heating water, (e) first and second reversing valves, (f) first and second 3-way valves, (f) a bi-directional electronic expansion valve, (g) a first bi-directional valve, and (h) a second bi-directional valve to modulate exchange of heat in the first load heat exchanger when operating as an evaporator and to control flashing of the refrigerant entering the source heat exchanger when operating as an evaporator, (h) a source pump for circulating the source fluid through the first load heat exchanger, (i) a water pump for circulating water through the second load heat exchanger, and (j) a controller to control operation of the foregoing.

A refrigeration cycle apparatus includes a compressor, a first heat exchanger, a decompressing device, a second heat exchanger, a first switching valve, a second switching valve, and a controller. The first switching valve is switched to one of a first state and a second state. The second switching valve is switched to one of a third state, a fourth state, and a fifth state. When switching to a second cooling operation to bring the first and second switching valves into the second and fourth states respectively, is requested during a first cooling operation to bring the first and second switching valves into the first and third states, respectively, the controller performs a first switching operation to bring the first switching valve into the second state and bring the second switching valve into the fifth state, and thereafter switches the first switching operation to the second cooling operation.

An air conditioning system includes a storage medium and an air conditioning system, for a three-pipe air conditioning system, the three-pipe air conditioning system includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, a gas-liquid separator, a first pipeline, a second pipeline and a third pipeline; the oil return control method comprises the following steps: controlling the compressor to operate at a first frequency in a refrigerating mode; judging whether the operation duration of the refrigerating mode reaches a first preset time or not; if so, the air conditioning system enters an oil return state, and the compressor, the third pipeline, the second pipeline and the gas-liquid separator are controlled to be communicated in sequence to form a refrigerant circulation loop.

Disclosed is an air conditioner and control method thereof. The air conditioner and control method thereof is to improve rapid heating performance without using a large-capacity compressor. The air conditioner includes an indoor unit having a first heat exchanger, an outdoor unit having a compressor and a second heat exchanger, a refrigerant cycle configured to form a refrigerant circulation path between the indoor unit and the outdoor unit, a flow path switch configured to switch a flow of a refrigerant in the refrigerant cycle, and a controller configured to control the flow path switch to allow one part of the refrigerant discharged from the compressor to flow into an inlet of the compressor and the other part of the refrigerant discharged from the compressor to flow into at least one of the first heat exchanger and the second heat exchanger.

Proposed by the present disclosure are an air conditioner, a control method and a computer-readable storage medium. The air conditioner includes: a refrigerant switching device, an indoor heat exchanger, an outdoor heat exchanger, a compressor, a memory, and a processor. The refrigerant switching device includes a liquid pipe, a gas pipe, and a valve assembly. The processor executes a computer program to execute the following: obtaining switching information of a working mode of the air conditioner; and controlling the valve assembly according to the switching information and the gas pipe and the liquid pipe are closed according to the sequence of the gas pipe first and then the liquid pipe, and then opened according to the sequence of the gas pipe first and then the liquid pipe.

Provided is a refrigeration cycle apparatus capable of achieving an improvement in heat exchange performance during a heating operation and during a cooling operation, while suppressing increases in manufacturing cost and volume required for packaging. The outdoor heat exchanger and the outdoor heat exchanger are connected in parallel to the indoor heat exchanger via the branch portion. The flow path switching device includes a first port, a second port, and a third port. The first port is connected with a third refrigerant flow path. The second port is connected with the outdoor heat exchanger. The third port is connected with a fourth refrigerant flow path. The second port is configured to switch between a state in which the second port is connected to the first port and a state in which the second port is connected to the third port.

Provided is a refrigeration cycle apparatus capable of achieving an improvement in heat exchange performance during a heating operation and during a cooling operation, while suppressing increases in manufacturing cost and volume required for packaging. The outdoor heat exchanger and the outdoor heat exchanger are connected in parallel to the indoor heat exchanger via the branch portion. The flow path switching device includes a first port, a second port, and a third port. The first port is connected with a third refrigerant flow path. The second port is connected with the outdoor heat exchanger. The third port is connected with a fourth refrigerant flow path. The second port is configured to switch between a state in which the second port is connected to the first port and a state in which the second port is connected to the third port.