A heat pump system adjusts a degree of subcooling of an indoor-side heat exchanger in a heating priority mode, and adjusts any one of a degree of subcooling of a hot-water supply-side heat exchanger (water-side heat exchanger) and a discharge temperature of a compressor in a hot-water supply priority mode.

A three-pipe, multi-split system and a control method thereof. The three-pipe multi-split system includes an outdoor unit, a multi-split indoor unit, and a hydraulic module. By optimizing a refrigerant system, the phenomenon that a refrigerant is throttled before flowing through a refrigerant heat dissipation module or supercooled when passing through a plate heat exchanger which causes a relatively low temperature of the refrigerant entering the refrigerant heat dissipation module and consequent condensation on the refrigerant heat dissipation module to produce condensate water and then causes a damage to a compressor frequency conversion module can be avoided. In addition, more refrigerant is caused to flow through the refrigerant heat dissipation module to reduce the temperature of the module.

A refrigeration cycle device according to the present disclosure includes: a refrigerant circuit including a compressor, a heat-source-side heat exchanger, a first expansion device, and a load-side heat exchanger, refrigerant cycling through the compressor, the heat-source-side heat exchanger, the first expansion device, and the load-side heat exchanger; a plurality of controllers configured to control the refrigerant circuit; a bypass pipe branching from a high pressure pipe on a discharge side of the compressor and connected to a low pressure pipe on a suction side of the compressor; a second expansion device provided to the bypass pipe, and configured to adjust a flow rate of the refrigerant flowing through the bypass pipe; and a plurality of refrigerant coolers provided to the bypass pipe, and configured to cool the plurality of controllers by using the refrigerant the flow rate of which is adjusted by the second expansion device, each of the plurality of refrigerant coolers including a refrigerant cooling pipe and a plate, the refrigerant cooling pipe forming the bypass pipe, the plate being joined between the refrigerant cooling pipe and a controller of the plurality of controllers.

A refrigeration cycle device according to the present disclosure includes: a refrigerant circuit including a compressor, a heat-source-side heat exchanger, a first expansion device, and a load-side heat exchanger, refrigerant cycling through the compressor, the heat-source-side heat exchanger, the first expansion device, and the load-side heat exchanger; a plurality of controllers configured to control the refrigerant circuit; a bypass pipe branching from a high pressure pipe on a discharge side of the compressor and connected to a low pressure pipe on a suction side of the compressor; a second expansion device provided to the bypass pipe, and configured to adjust a flow rate of the refrigerant flowing through the bypass pipe; and a plurality of refrigerant coolers provided to the bypass pipe, and configured to cool the plurality of controllers by using the refrigerant the flow rate of which is adjusted by the second expansion device, each of the plurality of refrigerant coolers including a refrigerant cooling pipe and a plate, the refrigerant cooling pipe forming the bypass pipe, the plate being joined between the refrigerant cooling pipe and a controller of the plurality of controllers.

Disclosed are embodiments of heat pump systems and methods for operating such systems in the heating mode while a heat pump operating parameter reaches or is equal to a predetermined operating value at which it is not advisable to use conventional heat pump systems for heating an enclosed structure. In addition to ancillary components, the heat pump systems includes indoor, outdoor and auxiliary heat exchangers, reversing and flow diverting valves, compressors, refrigerant superheat controllers, and auxiliary energy sources. During the heating mode of operation, while the heat pump operating parameter reaches or is equal to the predetermined operating value, the flow of liquid refrigerant through the outdoor heat exchangers is inhibited and is diverted to flow through the auxiliary heat exchangers. Thermal energy from the auxiliary energy source is used for evaporating the liquid refrigerant flowing through the auxiliary heat exchangers.