An outdoor unit 3 of an air conditioner 1 includes an outdoor control unit 31 having a first control mode and a second control mode different from each other as control modes of a refrigerant recovery operation for recovering a refrigerant of a refrigerant circuit 9. A flow rate of the refrigerant in the refrigerant circuit 9 in the first control mode is larger than a flow rate of the refrigerant in the refrigerant circuit 9 in the second control mode.

System and methods for OCR sensing with a suction-line accumulator are provided. The accumulator may include a sensor configured to detect the level of oil. The accumulator may further include a valve which opens when oil is at a high-level and closes when oil is at a low-level. The accumulator may measure a mass flow rate of oil in the vapor compression cycle system based on an amount of time taken to fill a portion of the accumulator. The accumulator may further determine an oil circulation ratio based on the measured time taken to fill the portion of the accumulator. The smart accumulator may output the oil circulation ratio.

An air conditioner switches between a normal refrigeration cycle and a defrosting refrigeration cycle, and includes: a refrigerant circuit that connects a first heat exchanger, a second heat exchanger, a radiation panel, and an expansion valve that regulates a flow rate of a refrigerant flowing through the radiation panel; and a controller that causes the air conditioner to switch between the normal refrigeration cycle and the defrosting cycle. During the normal refrigeration cycle, the radiation panel performs cooling or heating. During the defrosting cycle, the first heat exchanger serves as a radiator and the second heat exchanger serves as an evaporator. During the defrosting cycle, the controller causes the expansion valve to be in a fully closed state.

A hydrogen cooling apparatus according to an embodiment includes: a binary refrigeration unit including a high-temperature-side refrigerator and a low-temperature-side refrigerator; and a hydrogen-cooling-fluid circulation unit. The binary refrigeration unit cools a hydrogen cooling fluid circulated by the hydrogen-cooling-fluid circulation unit by means of a low-temperature-side evaporator of the low-temperature-side refrigerator. The high-temperature-side refrigerator includes: a high-temperature-side refrigeration circuit; and a high-temperature-side bypass circuit including: a high-temperature-side bypass flow path that extends from a part, which is downstream of a high-temperature-side compressor and upstream of a high-temperature-side condenser in the high-temperature-side refrigeration circuit, to a part, which is downstream of a high-temperature-side expansion valve and upstream of a high-temperature-side evaporator in the high-temperature-side refrigeration circuit; and a high-temperature-side opening and closing valve provided on the high-temperature-side bypass flow path. The high-temperature-side refrigerator opens the high-temperature-side opening and closing valve when a high-temperature-side refrigerant has an abnormal pressure.

A refrigeration cycle apparatus includes: a compressor, a first outdoor heat exchanger, and a second outdoor heat exchanger that; and a flow path switching mechanism configured to switch a flow direction of refrigerant compressed by the compressor in the refrigerant circuit. The first outdoor heat exchanger and the second outdoor heat exchanger are arranged to allow the refrigerant to flow in parallel in the refrigerant circuit. The refrigeration cycle apparatus further includes a flow rate adjustment mechanism configured to adjust an amount of refrigerant flowing through the second outdoor heat exchanger. When switching between a cooling operation and a heating operation, the flow path switching mechanism switches the flow direction of the refrigerant while the flow rate adjustment mechanism temporarily closes a refrigerant flow path to the second outdoor heat exchanger.

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains is a small-GWP refrigerant.

A refrigeration cycle apparatus includes a first refrigerant circuit including a first compressor, a first heat exchanger, a first refrigerant flow path of a second heat exchanger, a first expansion device, a third heat exchanger, and a second refrigerant flow path of a fourth heat exchanger, and a second refrigerant circuit including a second compressor, a fifth heat exchanger, a second expansion device, a third refrigerant flow path of the second heat exchanger, and a fourth refrigerant flow path of the fourth heat exchanger, a first refrigerant flows through, in order, the first compressor, the first heat exchanger, the first refrigerant flow path, the first expansion device, the third heat exchanger, and the second refrigerant flow path, the second refrigerant flows through, in order, the second compressor, the fifth heat exchanger, the second expansion device, the third refrigerant flow path, and the fourth refrigerant flow path.

A vehicle air-conditioning apparatus is provided which is capable of expanding an effective range of a dehumidifying and heating mode to achieve comfortable vehicle interior air conditioning. A control device (controller) executes a dehumidifying and heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, let a part of the refrigerant flow from a bypass circuit (refrigerant pipe 13F) to an indoor expansion valve 8, and let the residual refrigerant flow through an outdoor expansion valve 6. In the dehumidifying and heating mode, the control device has a state of controlling the operation of the compressor 2, based on a heat absorber temperature Te and executes a radiator temperature priority mode which enlarges a capability of the compressor when heat radiation in the radiator is insufficient.

An air conditioning unit capable of performing a refrigeration cycle using a small-GWP refrigerant is provided. A refrigeration cycle apparatus (1, 1a to 1m) includes a refrigerant circuit (10) including a compressor (21), a condenser (23, 31, 36), a decompressing section (24, 44, 45, 33, 38), and an evaporator (31, 36, 23), and a refrigerant containing at least 1,2-difluoroethylene enclosed in the refrigerant circuit (10).

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit which includes a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which water is circulated, a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a water tube configured to guide the water circulated through the indoor unit and the heat exchanger, a pump installed in the water tube, and a controller configured to analyze an output signal of the pump so as to calculate a ration of an air layer in the water tube, the controller being configured to control a target supercooling degree or target superheating degree of the heat exchanger according to the calculated ratio of the air layer.