Provided is an air-conditioning apparatus including a switching valve and a bypass circuit. The switching valve is provided between an expansion valve and an outdoor heat exchanger. The bypass circuit has a first end connected to a refrigerant pipe connecting a compressor and an indoor heat exchanger to each other, and a second end connected to the switching valve. During a heating operation, the air-conditioning apparatus causes a rotating member of the switching valve to rotate to sequentially connect, to the bypass circuit, flow passages of the outdoor heat exchanger connected in parallel, to thereby defrost the outdoor heat exchanger while performing the heating operation.

A controller switches between and performs a first simultaneous heating and defrosting operation of supplying part of refrigerant discharged from a compressor is supplied to one or some parallel heat exchangers among a plurality of parallel heat exchangers through a defrosting circuit and allowing the other one or more parallel heat exchangers to operate as evaporators, and a second simultaneous heating and defrosting operation of, in one or some heat source units among a plurality of heat source units, supplying the refrigerant discharged from the compressor is supplied to all the plurality of parallel heat exchangers through the defrosting circuit, and in the other one or more heat source units, continuing heating by allowing all the plurality of parallel heat exchangers to operate as evaporators.

An air conditioner including a hot gas line for receiving a portion of refrigerant compressed in a compressor, an indoor heat exchanger, an outdoor expansion device for expanding the refrigerant having exchanged heat in the indoor heat exchanger, an outdoor heat exchanger functioning as a condenser in a cooling mode while functioning as an evaporator in a heating mode, and a 4-way valve for receiving a remaining portion of the compressed refrigerant, to guide the refrigerant emerging from the compressor to the outdoor heat exchanger in the cooling mode and to the indoor heat exchanger in the heating mode. The outdoor heat exchanger includes a main heat exchanger section functioning as a condenser in the cooling mode while functioning as an evaporator in the heating mode, and an auxiliary heat exchanger for receiving the refrigerant from the hot gas line in a frosting prevention mode.

An air conditioner includes a refrigeration cycle in which a first compressor and a second compressor are connected in parallel, and the first compressor, the second compressor, a first outdoor heat exchanger, a second outdoor heat exchanger, a first indoor heat exchanger, a second indoor heat exchanger, and expansion valves are connected. When the air conditioning apparatus is operated in a first operation mode in which the second outdoor heat exchanger and the first indoor heat exchanger are operated as condensers and the second indoor heat exchanger is operated as an evaporator, refrigerant discharged from the first compressor flows through the first indoor heat exchanger, the expansion valves, and the second indoor heat exchanger in order while bypassing the first outdoor heat exchanger and the second outdoor heat exchanger.

The air conditioner has a configuration such that, in an air-warming operation: the average refrigerant exit temperature, which is obtained by averaging the temperature of the refrigerant exits of indoor heat exchangers 7 in a plurality of indoor units 10, as detected by heat-exchanger-refrigerant-exit temperature probes 34 in the indoor units 10, is determined; the temperature difference between the average refrigerant exit temperature and the refrigerant exit temperatures of the indoor heat exchangers 7 of each of the indoor units 10 is determined; and the degree to which indoor expansion valves 9 of the indoor units 10 are open is controlled such that the determined temperature difference falls within a predetermined temperature difference range.

An outdoor unit being part of a refrigeration cycle apparatus in which refrigerant circulates and having a maintenance opening port includes an open-close panel configured to cover the maintenance opening port by being attached openably and closably to the outdoor unit, a heat source side heat exchanger disposed above the maintenance opening port and provided at least with an open-close panel-facing heat exchange unit facing a plane containing the open-close panel, a drainage channel located at least below the open-close panel-facing heat exchange unit of the heat source side heat exchanger, wherein the heating energy supply unit includes a refrigerant pipe configured to pass refrigerant higher in temperature than a freezing point of water in an upstream direction from a downstream direction of the drainage channel.

An air-conditioner is provided with a flow path including a portion through which a gas distributor, a second part, a first part, and a gas-liquid two-phase distributor are sequentially connected. The air-conditioner is provided with another flow path including a portion through which a gas distributor, a third part, a fourth part, and a gas-liquid two-phase distributor are sequentially connected. The flow path and another flow path are connected in parallel with respect to a refrigeration cycle circuit in such a manner that the gas-liquid two-phase distributor and the gas-liquid two-phase distributor are connected and the gas distributor and the gas distributor are connected. The first part is arranged on a windward side and the second part is arranged on a leeward side. The third part is arranged on the windward side and the fourth part is arranged on the leeward side.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

An air conditioner provided which has: a main refrigerant circuit including a compressor, a heat source side heat exchanger, a first expansion valve, and a utilization side heat exchanger and configured such that refrigerant flows in the main refrigerant circuit; a sub refrigerant circuit including a cooling member configured such that refrigerant branched from the main refrigerant circuit flows in the cooling member and configured such that refrigerant branched from the main refrigerant circuit flows in the sub refrigerant circuit; and a heat generator to be cooled by the cooling member, wherein a pipe in which part of refrigerant discharged from the compressor flows is connected to the cooling member of the sub refrigerant circuit.

An ejector for a sealed system includes a motive liquid passage with a converging section, a throat and a diverging section. The throat of the motive liquid passage is disposed between the converging section of the motive liquid passage and the diverging section of the motive liquid passage. The ejector also includes a plurality of nucleation sites at the converging section of the motive liquid passage.