Abstract: An air-conditioning apparatus is capable of efficiently performing defrosting operation without suspending a heating operation of an indoor unit. The air-conditioning apparatus includes a main circuit sequentially connecting, via a pipe, a compressor, indoor heat exchangers, first flow control devices, and a plurality of parallel heat exchangers connected in parallel to each other to allow refrigerant to circulate, first defrost pipes branching a part of the refrigerant discharged from the compressor and causing the part of the refrigerant to flow into one of the plurality of parallel heat exchangers and to be defrosted, an interface heat exchanger located between the plurality of parallel heat exchangers, a first bypass pipe branching a part of the refrigerant discharged from the compressor and causing the part of the refrigerant to flow into the interface heat exchanger, and a second bypass pipe causing the part of the refrigerant flowing out of the interface heat exchanger to flow into the main circuit.

Abstract: An outdoor cooling unit in a vehicle air-conditioning apparatus is configured such that the angle between a normal line to a suction plane of a suction portion and a normal line to a discharge plane of a discharge portion is acute and such that air inside a housing flows in a substantially checkmark-shape, substantially V shape or substantially U shape. In the outdoor cooling unit, a blade of an axial fan is configured such that a chord center line formed by connecting chord central points from an inner circumferential end to an outer circumferential end of the blade and projecting the connected chord central points on a plane containing a rotating shaft is convexly curved toward the downstream side over the entire area in the radial direction.

Abstract: An air-conditioning apparatus divides an outdoor heat exchanger to form parallel heat exchangers and supplies part of refrigerant from a compressor to the parallel heat exchangers alternately to perform defrosting, performs medium-pressure defrosting in which part of the refrigerant from the compressor is decompressed and supplied to a parallel heat exchanger to be subjected to defrosting, and the refrigerant after being used for defrosting is injected into the compressor. A first flow switching unit performs switching of a connection mode of ends of the parallel heat exchangers on compressor side, where the pressure changes among high pressure, medium pressure, and low pressure according to operation contents, to one of three modes: a mode with the ends connected to the compressor discharge side, a mode with the ends connected to the compressor suction side, and a mode with the ends connected to neither the discharge nor suction side.

Abstract: An air-conditioning apparatus including a refrigeration cycle configured by connecting one or more load-side units including a load-side heat exchanger and a load-side expansion device with a heat-source-side unit including a heat-source-side heat exchanger and a compressor and by causing refrigerant to circulate through a refrigerant circuit including the load-side heat exchanger, the load-side expansion device, the heat-source-side heat exchanger, and the compressor, controls, during a heating operation, the opening degree of the load-side expansion device, based on the discharge pressure of the compressor, so that the pressure of refrigerant at the outlet of the compressor becomes equal to a target pressure, in the case where the operation capacity of the compressor is approximately at the maximum value of the operation capacity of the compressor.

Abstract: An outdoor unit, connected with indoor units by pipes to constitute a refrigerant circuit, includes a compressor configured to compress and discharge refrigerant, a plurality of parallel heat exchangers configured to allow heat exchange between air and the refrigerant, a first defrosting pipe serving as a flow path for branching a part of the refrigerant discharged by the compressor and allowing the refrigerant to flow into the parallel heat exchanger to be defrosted for defrosting, a first expansion device configured to decompress the refrigerant passing through the first defrosting pipe, a second expansion device configured to adjust the pressure of the refrigerant that passed through the parallel heat exchanger to be defrosted, and a controller configured to control the second expansion device such that the pressure of the refrigerant that passed through the parallel heat exchanger to be defrosted falls within a predetermined range.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, an indoor heat exchanger, a first flow control device, and a plurality of parallel heat exchangers connected in parallel to each other are sequentially connected via a pipe to allow refrigerant to circulate, a first defrost pipe that branches a part of the refrigerant discharged from the compressor and allows the refrigerant to flow into the parallel heat exchanger to be defrosted among the plurality of parallel heat exchangers, a expansion device provided in the first defrost pipe and configured to depressurize the refrigerant discharged from the compressor, and a connection switching device that allows the refrigerant flowing out of the parallel heat exchanger to be defrosted to flow into the main circuit at a position upstream of the parallel heat exchangers other than the parallel heat exchanger subject to defrosting.

Abstract: An air-conditioning apparatus includes an outdoor unit including a compressor configured to compress a first-side refrigerant and a heat-source-side heat exchanger configured to cause heat exchange between air and the first-side refrigerant, plural indoor units including indoor heat exchangers configured to cause heat exchange between the air and a second-side refrigerant, plural intermediate heat exchangers configured to cause heat exchange between the first-side and second-side refrigerants and connected to the outdoor unit by a first-side refrigerant pipe and connected to the indoor units by a second-side refrigerant pipe, and a flow switching device configured to switch combination of connection between the indoor units and the intermediate heat exchangers. The indoor units include convective indoor units and radiant indoor units, the convective indoor units include a convective indoor heat exchanger, and the radiant indoor units include a radiant indoor heat exchanger.

Abstract: An air-conditioning apparatus includes a refrigerant circuit formed by connecting pipes, a compressor including a compression chamber and an injection port through which refrigerant is introduced into the compression chamber, a first heat exchanger, a subcooling heat exchanger that includes a first flow passage and a second flow passage and exchanges heat between refrigerant flowing in the first flow passage and refrigerant flowing in the second flow passage to subcool the refrigerant flowing in the first flow passage, a first expansion device, a second heat exchanger, and an accumulator In addition, a first bypass pipe connects the second flow passage of the subcooling heat exchanger with a segment of the pipes, positioned on a refrigerant inflow side of the accumulator; an expansion device to adjust a flow rate of the refrigerant flowing in the first bypass pipe; a second bypass pipe that connects a segment of the pipes with the injection port, the segment being positioned between the first heat exchanger a

Abstract: An air-conditioning apparatus includes a selection unit and a determination unit, the selection unit selecting a reverse-defrosting operation mode or a heating-defrosting simultaneous operation mode, the reverse-defrosting operation mode being a mode in which all of parallel heat exchangers are defrosted by stopping a heating operation, the heating-defrosting simultaneous operation mode being a mode in which each parallel heat exchanger is sequentially defrosted while continuing a heating operation, the determination unit determining whether or not a defrosting operation is to be started, in which the determination unit is configured to start the defrosting operation in a state where the amount of frost deposited on the parallel heat exchangers is smaller in a case where the heating-defrosting simultaneous operation mode is selected than in a case where the reverse-defrosting operation is selected.

Abstract: An air-conditioning apparatus includes a refrigerant circuit formed by connecting, with pipes, a compressor, a first refrigerant flow switching device, a heat-source-side heat exchanger, an expansion device, and a plurality of intermediate heat exchangers. A heat medium circuit is formed by connecting, with pipes, a plurality of pumps configured to pressurize and circulate the heat medium subjected to heat exchange in the plurality of intermediate heat exchangers, a plurality of use-side heat exchangers each configured to exchange heat between the heat medium and air in an air-conditioned space, and a heat-medium flow switching/control device configured to switch which of the heat medium is to be allowed to flow into and out of each of the use-side heat exchangers; and a controller configured to perform processing for controlling the switching performed by the heat-medium flow switching/control device, in accordance with a capacity of each of the use-side heat exchangers.

Abstract: A second space communicated with a first space through communicating paths is provided on an outer circumferential side of first and second scroll bodies. Scroll end portions of the first and second scroll bodies form an inlet port configured to suck gas refrigerant into a compression chamber from the second space. Open ends of the communicating paths on a side of the second space are located at an angle larger than 0° and less than or equal to 180°, around a central axis of a rotating shaft portion, from the inlet ports in a scroll involute direction of the first scroll body and the second scroll body, respectively. Injection ports in a part of an outer circumference of the second space between the open ends and the inlet ports in a circumferential direction are configured to eject liquid refrigerant in a direction toward the inlet ports, respectively.

Abstract: A refrigeration cycle apparatus including a heat source side heat exchanger including a first heat exchanger and a second heat exchanger connected in parallel; an air-sending device that supplies air, which is an object to be heat exchanged in the first heat exchanger and the second heat exchanger, in a variable manner; solenoid valves that each opens and closes a refrigerant passage of the first heat exchanger and the second heat exchanger; a third refrigerant circuit that is parallelly connected to the first heat exchanger and the second heat exchanger; and a flow control valve that controls the flow rate of the refrigerant flowing in the third refrigerant circuit. The refrigeration cycle apparatus can improve continuity of control of a heat exchange capacity of a heat source side heat exchanger.

Abstract: A channel on an upstream side of a third expansion device and a channel on an upstream side of a second expansion device are connected during a heating operation, and medium pressure refrigerant generated by the third expansion device during the heating operation is introduced on a suction side of a compressor via the second expansion device and a suction injection pipe.

Abstract: An air-conditioning apparatus includes a refrigeration cycle circulating refrigerant and connecting a compressor, a heat-source-side heat exchanger, one or more of load-side expansion devices, and one or more of load-side heat exchangers by refrigerant pipes, a bypass having one end connected to a discharge side of the compressor of the refrigeration cycle and the other end connected to a suction side of the compressor of the refrigeration cycle to bypass a portion of the refrigerant discharged from the compressor, a first expansion device depressurizing the refrigerant flowing through the bypass, an auxiliary heat exchanger cooling the refrigerant depressurized at the first expansion device, a second expansion device controlling a flow rate of the refrigerant flowing from the auxiliary heat exchanger to the suction side of the compressor, and a controller controlling an opening degree of the second expansion device.

Abstract: When indoor units are performing a cooling operation, an air-conditioning apparatus controls four flow passage switching valves, for example a first solenoid valve, a second solenoid valve, a third solenoid valve, and a fourth solenoid valve, so that a number of intermediate heat exchangers operating as evaporators is greater than in a cooling main operation. During the cooling main operation, a target value for suction pressure or evaporating temperature at a compressor is set equal to or lower than that in a case in which the indoor units are performing the cooling operation, and a frequency of the compressor and a capacity of a heat-source-side heat exchanger are controlled.

Abstract: An air-conditioning apparatus includes an outdoor-side flow rate control device (a fourth flow rate control device) that generates an intermediate pressure for injection into a compressor, and a bypass flow rate control device (a sixth flow rate control device) that is placed at a bypass pipe allowing bypassing of an outdoor heat exchanger in parallel to the outdoor-side flow rate control device and that controls the amount of heat exchange of the outdoor heat exchanger together with the outdoor-side flow rate control device.

Abstract: An air-conditioning apparatus, including an outdoor unit including a compressor and an outdoor heat exchanger, a plurality of indoor units each including an indoor heat exchanger, and a relay unit configured to distribute refrigerant supplied from the outdoor unit to the plurality of indoor units, the relay unit including a first branch unit in which liquid-side pipes connected to the plurality of indoor units join together, and a refrigerant shutoff valve, which is configured to control bidirectional flow of the refrigerant, and is provided to the first branch unit, the number of the refrigerant shut off valve being smaller than a number of the plurality of indoor units.

Abstract: An air-conditioning apparatus includes a bypass pipe that has one end connected to the discharge side of a compressor and through which refrigerant exiting the compressor flows, an auxiliary heat exchanger that is connected to the other end of the bypass pipe and the suction part of the compressor, and cools refrigerant flowing through the bypass pipe and supplies the cooled refrigerant to the suction part of the compressor, and a flow regulating unit that is provided on the refrigerant outlet side of the auxiliary heat exchanger, and regulates the flow rate of refrigerant routed into the suction part of the compressor from the auxiliary heat exchanger.

Abstract: An air-conditioning apparatus includes a refrigerant circuit including a low-pressure shell structure compressor into which a refrigerant flowing through an injection pipe flows, a first heat exchanger, a second heat exchanger, a first expansion device, a refrigerant flow switching device, and a second expansion device configured to allow the refrigerant which has passed through the first expansion device and flows from the second heat exchanger to the first heat exchanger to have an intermediate pressure, the compressor, the first heat exchanger, the second heat exchanger, the first expansion device, the refrigerant flow switching device, and the second expansion device being connected by pipes to constitute the refrigerant circuit, and further includes a controller that controls an amount of refrigerant flowing through the injection pipe into a compression chamber. A part of a high-pressure refrigerant flowing from the first heat exchanger to the second heat exchanger flows through the injection pipe.

Abstract: An air-conditioning apparatus includes a heat medium circuit with a heat medium flow reversing device that can switch the flow direction of a heat medium in the heat medium side passage of the heat exchanger related to heat medium.