Abstract: A refrigeration cycle apparatus includes a compressor, a four-way valve, a first outdoor heat exchanger, a first expansion valve, and an indoor heat exchanger. The four-way valve includes a casing, a first flow channel, a second flow channel, a flow channel switching piston, and a wall portion. The flow channel switching piston is configured to slide along an inner surface to switch between passing the refrigerant through the first flow channel and passing the refrigerant through the second flow channel. The wall portion is configured to slide along the inner surface together with the flow channel switching piston and is disposed with a space between the flow channel switching piston and wall portion to cover the flow channel switching piston.

Abstract: A refrigeration cycle apparatus includes a first flow switch valve including first to fourth ports, a second flow switch valve and a third flow switch valve each including fifth to seventh ports, a compressor, a discharge pipe connecting a discharge port of the compressor and the first port, a first high pressure pipe connecting between the discharge pipe and the fifth ports, a bypass expansion valve provided at a part of the first high pressure pipe, the part extending, a first outdoor heat exchanger connected to the seventh port of the second flow switch valve, a second outdoor heat exchanger connected to the seventh port of the third flow switch valve, and a controller. The controller is configured to perform a differential pressure ensuring process, when switching the second flow switch valve or the third flow switch valve.

Abstract: An outdoor unit includes a casing including an air passage, an outdoor fan disposed in the air passage, a compressor disposed in the casing, an outdoor heat exchanger disposed in the casing and including fins and a heat transfer tube connected to the fins, a control board disposed in the casing and including a control unit that controls the compressor, and a heat sink disposed in the air passage in the casing and being in contact with the control board. The heat transfer tube of the outdoor heat exchanger includes a first region in which gas refrigerant or two-phase gas-liquid refrigerant flows when the outdoor heat exchanger is used as a condenser and a second region that is located downstream of the first region in a refrigerant flow direction and in which single-phase liquid refrigerant flows.

Abstract: 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.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, a flow switching device, an indoor heat exchanger, a pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe, a flow control device provided to the bypass pipe and configured to adjust a flow rate of refrigerant flowing through the bypass pipe, an evaporating pressure sensor configured to measure an evaporating pressure of the refrigerant, and a controller. The air-conditioning apparatus is configured to operate in a normal heating operation mode and a heating-defrosting operation mode. When an operation associated with the normal heating operation mode is switched to an operation associated with the heating-defrosting operation mode, the controller adjusts an opening degree of the flow control device using the evaporating pressure in the parallel heat exchanger and a driving frequency of the compressor.

Abstract: An air-conditioning apparatus includes a refrigerant circuit in which a compressor, an indoor heat exchanger, a first expansion device, an outdoor heat exchanger, and a flow switching device are sequentially connected to each other; a hot gas bypass pipe coupling a discharge port of the compressor and the flow switching device to each other; and a controller. The outdoor heat exchanger includes an upper heat exchanger and a lower heat exchanger having passages in parallel with each other. The outdoor heat exchanger includes a plurality of hairpin pipes, which are part of a heat transfer pipe. When the upper heat exchanger is defrosted, all hairpin pipes that are located at a lowermost step of the upper heat exchanger are used as refrigerant inlets. When the lower heat exchanger is defrosted, all hairpin pipes that are located at an uppermost step of the lower heat exchanger are used as refrigerant inlets.

Abstract: A heat exchanger includes a heat transfer tube. The heat transfer tube includes a first tube portion, and a plurality of second tube portions connected in parallel with each other with respect to the first tube portion. The first tube portion has a first inner circumferential surface, and a plurality of first grooves recessed relative to the first inner circumferential surface and arranged side by side in a circumferential direction of the heat transfer tube. The plurality of second tube portions each have a second inner circumferential surface, and a plurality of second grooves recessed relative to the second inner circumferential surface and arranged side by side in the circumferential direction. The plurality of first grooves are less than the plurality of second grooves in at least one of a number of grooves, a depth of each groove, and a lead angle of each groove.

Abstract: A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

Abstract: A condenser includes: a first heat exchange portion and a second heat exchange portion that are configured such that refrigerant in the first heat exchange portion flows in parallel with refrigerant in the second heat exchange portion; a flow rate restricting portion configured to cause a flow rate difference between a flow rate of the refrigerant passing through the first heat exchange portion and a flow rate of the refrigerant passing through the second heat exchange portion. An air conditioner includes a controller configured to control a compressor and a flow rate restricting portion. When the controller changes an air conditioning capability of the air conditioner, the controller uses a combination of a frequency of the compressor and the flow rate difference between the refrigerants passing through two heat exchange portions.

Abstract: An air-conditioning apparatus includes a first flow switching unit configured to be switched between a first state in which refrigerant communication between a compressor and a second load-side heat exchanger is blocked and a second state in which the compressor is in refrigerant communication with a first load-side heat exchanger and the second load-side heat exchanger. The air-conditioning apparatus further includes a second flow switching unit configured to be switched between a third state in which refrigerant communication between the second load-side heat exchanger and a heat-source-side heat exchanger is blocked and a fourth state in which the first load-side heat exchanger is in refrigerant communication with the second load-side heat exchanger and the heat-source-side heat exchanger. The first heat exchanger is located upstream of the second load-side heat exchanger. The second flow switching unit is located downstream of the second load-side heat exchanger.

Abstract: An air conditioner (10) includes a refrigerant circuit (13) and refrigerant. The refrigerant circuit (13) has a compressor (1), a condenser (2), a pressure-regulating valve (3), and an evaporator (4). The refrigerant is R32. The pressure-regulating valve (3) includes a flow path (33) causing the refrigerant flowing from the condenser (2) to flow to the evaporator (4), a pressure reference chamber (S2) partitioned from the flow path (33) and filled with inert gas, and a valve portion (34) disposed in the flow path (33). The pressure-regulating valve (3) is configured to adjust a degree of opening of the valve portion (34) to adjust a flow rate of the refrigerant flowing through the flow path (33). The valve portion (34) is configured to increase the degree of opening when a pressure in the flow path (33) is higher than a pressure in the pressure reference chamber (S2), and reduce the degree of opening when the pressure in the flow path (33) is lower than the pressure in the pressure reference chamber (S2).

Abstract: An air conditioner (10) includes a refrigerant circuit (13) and refrigerant. The refrigerant circuit (13) has a compressor (1), a condenser (2), a pressure-regulating valve (3), and an evaporator (4). The refrigerant is R32. The pressure-regulating valve (3) includes a flow path (33) causing the refrigerant flowing from the condenser (2) to flow to the evaporator (4), a pressure reference chamber (S2) partitioned from the flow path (33) and filled with inert gas, and a valve portion (34) disposed in the flow path (33). The pressure-regulating valve (3) is configured to adjust a degree of opening of the valve portion (34) to adjust a flow rate of the refrigerant flowing through the flow path (33). The valve portion (34) is configured to increase the degree of opening when a pressure in the flow path (33) is higher than a pressure in the pressure reference chamber (S2), and reduce the degree of opening when the pressure in the flow path (33) is lower than the pressure in the pressure reference chamber (S2).

Abstract: An air conditioner includes a switching valve, a flow rate restricting portion and an on-off valve. The switching valve provided in a flow path between a compressor and an outdoor heat exchanger. The outdoor heat exchanger includes a heat exchange portion and a heat exchange portion. During heating operation, the switching valve causes a second connection port, a third connection port and a first connection port to communicate with one another. The flow rate restricting portion and the on-off valve are connected in series between an outlet and an inlet of the compressor during the heating operation, to bypass a part of refrigerant. During defrosting operation of the heat exchange portion, the switching valve is configured such that a fourth connection port and the second connection port communicate with each other, and the third connection port and the first connection port communicate with each other.

Abstract: A vehicle air-conditioning apparatus includes a refrigerant circuit including a heat exchanger, a fan which sends air to the heat exchanger, and a controller which controls the refrigerant circuit and the fan. The vehicle air-conditioning apparatus is mounted on a vehicle. The controller determines if a position of the vehicle or a speed of the vehicle satisfies a predetermined condition. The controller acquires a physical quantity, the physical quantity having already been correlated with a clogging amount of the heat exchanger and the correlation being dependent on whether the predetermined condition is satisfied. The controller determines whether or not clogging occurs in the heat exchanger based on the physical quantity.

Abstract: The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

Abstract: When a controller performs a defrosting operation in which frost on an outdoor heat exchanger is caused to be melted, the controller is configured to perform a first defrosting control in which a switching state of a switching device is set to a first state, after the controller performs the first defrosting control, perform a second defrosting control in which the switching state of the switching device is set to a second state, and after the controller performs the second defrosting control, perform a third defrosting control in which the switching state of the switching device is set to the first state.

Abstract: A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

Abstract: A vehicle air-conditioning apparatus includes a refrigerant circuit and a control unit which controls the refrigerant circuit, and is mounted on a vehicle. The control unit determines whether or not the vehicle is stationary based on position information or speed information on the vehicle, causes the refrigerant circuit to operate when the vehicle is stationary, acquires state data on the refrigerant circuit at the time when the vehicle is stationary, and detects whether abnormality occurs in the refrigerant circuit based on the state data.

Abstract: An air-conditioning apparatus includes a refrigerant circuit including first and second load-side heat exchangers, a first flow switching unit located upstream of the second load-side heat exchanger, and a second flow switching unit located downstream of the second load-side heat exchanger, wherein the first flow switching unit is configured to be switched between a first state in which refrigerant communication between a compressor and the second load-side heat exchanger is blocked and a second state in which the compressor is in refrigerant communication with the first and second load-side heat exchangers, and the second flow switching unit is configured to be switched between a third state in which refrigerant communication between the second load-side heat exchanger and a heat-source-side heat exchanger is blocked and a fourth state in which the first load-side heat exchanger is in refrigerant communication with the second load-side heat exchanger and the heat-source-side heat exchanger.

Abstract: An air conditioner includes a compressor, a condenser, an expansion valve, an evaporator, and a temperature detection unit. The temperature detection unit is attached to the condenser and is configured to detect a temperature of the refrigerant in the condenser. The expansion valve is configured to be capable of adjusting a flow rate per unit time of the refrigerant flowing through the expansion valve by adjusting a degree of opening of the expansion valve. The degree of opening of the expansion valve is increased when the temperature of the refrigerant detected by the temperature detection unit rises, and the degree of opening of the expansion valve is decreased when the temperature of the refrigerant detected by the temperature detection unit falls.