A refrigeration cycle apparatus includes: a refrigerant circuit configured to circulate refrigerant; and a controller configured to control the refrigerant circuit. The refrigerant circuit includes a compressor, a first heat exchanger, a first expansion device, a second expansion device, a third expansion device, a second heat exchanger, and a cooler configured to cool a substrate of the controller. In a first path of the refrigerant circuit, the compressor, the first heat exchanger, the first expansion device, the second expansion device, and the second heat exchanger are connected in order of the compressor, the first heat exchanger, the first expansion device, the second expansion device, and the second heat exchanger. In a second path of the refrigerant circuit, the cooler and the third expansion device are connected in order of the cooler and the third expansion device from a first point between the first expansion device and the second expansion device to a second point between the compressor and the second heat exchanger.

A refrigeration cycle apparatus includes: a refrigerant circuit configured to circulate refrigerant; and a controller configured to control the refrigerant circuit. The refrigerant circuit includes a compressor, a first heat exchanger, a first expansion device, a second expansion device, a third expansion device, a second heat exchanger, and a cooler configured to cool a substrate of the controller. In a first path of the refrigerant circuit, the compressor, the first heat exchanger, the first expansion device, the second expansion device, and the second heat exchanger are connected in order of the compressor, the first heat exchanger, the first expansion device, the second expansion device, and the second heat exchanger. In a second path of the refrigerant circuit, the cooler and the third expansion device are connected in order of the cooler and the third expansion device from a first point between the first expansion device and the second expansion device to a second point between the compressor and the second heat exchanger.

An air conditioning system includes a compressor and a refrigerant line. A power generating unit may be disposed along the refrigerant line to generate power from the heat in the refrigerant line while helping to convert hot compressed refrigerant gas into a hot high-pressure refrigerant liquid. An air conditioning system may also involve using a cooling chamber to use refrigerant to cool a heat exchange medium which is then used in a cooling coil to condition air.

An air conditioning system includes a compressor and a refrigerant line. A power generating unit may be disposed along the refrigerant line to generate power from the heat in the refrigerant line while helping to convert hot compressed refrigerant gas into a hot high-pressure refrigerant liquid. An air conditioning system may also involve using a cooling chamber to use refrigerant to cool a heat exchange medium which is then used in a cooling coil to condition air.

A method for operating a refrigeration system for a motor vehicle. The method includes setting an operating mode of the refrigeration system having active primary line and inactive secondary line or having active secondary line and inactive primary line; detecting the pressure in the inactive line; and activating and extraction of refrigerant from the inactive line into the active line by lowering the pressure in the active line to a value below the pressure in the inactive line and by opening the relevant valve device.

A refrigeration system and a control method thereof. The refrigeration system includes a compressor and a condenser, and further includes a first throttling device for receiving liquid refrigerant from the condenser; an ejector having a high-pressure fluid inlet, a fluid suction inlet and a fluid outlet, the high-pressure fluid inlet of the ejector is connected to the first throttling device, the fluid outlet of the ejector is connected to a flash tank, a gas-phase outlet of the flash tank is connected to a compressor inlet, a liquid-phase outlet of the flash tank is connected to an evaporator via a second throttling device, and the evaporator is connected to the fluid suction inlet of the ejector; and a controller configured to control an opening of the first throttling device based on a pressure difference between the fluid outlet and the fluid suction inlet of the ejector.

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.

In a refrigeration cycle apparatus according to the present disclosure, the circulation direction of refrigerant is switched between a first circulation direction and a second circulation direction opposite to the first circulation direction. The first circulation direction is a circulation direction in order of a compressor, a first heat exchanger, a first expansion valve, a third heat exchanger, a fourth heat exchanger, a second expansion valve, and a second heat exchanger. When a circulation direction of the refrigerant is the first circulation direction, the refrigerant from the third heat exchanger exchanges heat with the refrigerant from the second heat exchanger in the fourth heat exchanger. When a circulation direction of the refrigerant is the second circulation direction, the refrigerant from the fourth heat exchanger exchanges heat with the refrigerant from the first heat exchanger in the third heat exchanger.

A heat releasing unit includes heat releasing constituents which are stacked and are joined together while heat releasing flow passages are formed in the heat releasing constituents, respectively. An evaporating unit includes evaporating constituents which are stacked and are joined together, while evaporating flow passages are formed in the evaporating constituents, respectively. The evaporating unit and the heat releasing unit are arranged one after another in a direction along a side plate portion. A heat releasing unit outlet is formed at an outlet-side heat releasing constituent that is one of the heat releasing constituents placed at an end thereof. An evaporating unit inlet is formed at an inlet-side evaporating constituent that is one of the evaporating constituents placed at an end thereof. All of the heat releasing flow passages are connected to the evaporating flow passages through the heat releasing unit outlet and the evaporating unit inlet.