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).

A compressor includes a housing, a shaft that is rotated relative to the housing to compress a working fluid, and a foil bearing that supports the shaft. The foil bearing includes a top foil. The foil bearing is a foil gas bearing that is backed up by a ball bearing, or a mesh foil bearing with an actuator to compress a wire mesh dampener. A heat transfer circuit includes a compressor and a working fluid. The compressor includes a shaft that is rotated to compress the working fluid, and a foil bearing for supporting the shaft as it rotates.

A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and an aperture. A porous surface layer is disposed within the housing surrounding the aperture in a circumferential direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a damping system including a biasing member, the biasing member being disposed in a passageway that extends along the longitudinal direction of the aperture and circumferentially about the aperture, wherein the biasing member is arranged radially outward from the porous surface layer.

There is provided a refrigeration cycle apparatus in which good lubricity can be achieved when a refrigeration cycle is performed using a refrigerant having a sufficiently low GWP. The refrigeration cycle apparatus contains a refrigerating oil and a refrigerant composition containing a refrigerant containing trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).

High power of a compressor that compresses a mixed refrigerant containing at least 1,2-difluoroethylene is achieved. A compressor (100) employs an induction motor (70) as a motor that drives a compression unit (60) that compresses a mixed refrigerant containing at least 1,2-difluoroethylene, and thus, high power is enabled at comparatively low costs.

High efficiency of a compressor that compresses a mixed refrigerant containing at least 1,2-difluoroethylene is achieved. A compressor (100) includes a motor (70) that has a rotor (71) including permanent magnets (712) and thus is suitable for a variable capacity compressor in which the number of rotations of the motor can be changed. In this case, it is possible to change the number of rotations of the motor in accordance with an air conditioning load in an air conditioner (1) that uses a mixed refrigerant containing at least 1,2-difluoroechylene. It is thus possible to enable high efficiency of the compressor (100).

A heat exchange unit is provided with which, even if a flammable refrigerant is used, the likelihood of the refrigerant reaching an electric component unit is reduced. An outdoor unit (20) constitutes a portion of an air-conditioning apparatus (1), and is connected to an indoor unit (30) via a liquid-side refrigerant connection pipe (6) and a gas-side refrigerant connection pipe (5). The outdoor unit (20) includes an outdoor housing (50), an outdoor heat exchanger (23) disposed inside the outdoor housing (50) and in which a refrigerant flows, a liquid-side shutoff valve (29) connected to the liquid-side refrigerant connection pipe (6), a gas-side shutoff valve (28) connected to the gas-side refrigerant connection pipe (5), and an outdoor electric component unit (8) disposed inside the outdoor housing (50). The refrigerant is a flammable refrigerant containing at least 1,2-difluoroethylene. When the outdoor unit (20) is in its installed state, the lower end of the outdoor electric component unit (8) is positioned above the liquid-side shutoff valve (29) and the gas-side shutoff valve (28).

An air conditioning apparatus 1 includes a compressor (321), an indoor heat exchanger (242) that is a use-side heat exchanger that exchanges heat with first air (F1), an outdoor heat exchanger (323) that is a heat-source-side heat exchanger that exchanges heat with second air, a refrigerant, a first duct (209), and a casing (230). The refrigerant contains at least 1,2-difluoroethylene, and circulates in the compressor (321), the indoor heat exchanger (242), and the outdoor heat exchanger (323) to repeat a refrigeration cycle. The first duct (209) supplies the first air (F1) to a plurality of rooms in an interior. The casing (230) includes a use-side space (SP2) that is connected to the first duct (209) and that accommodates the indoor heat exchanger (242). The casing (230) is configured to allow the first air (F1) after heat exchange with the refrigerant at the indoor heat exchanger (242) to be sent out to the first duct (209).

A heat transfer circuit that includes a compressor with a gas bearing, a condenser, an expander, an evaporator, a lubricant stream, and a heat source. The lubricant stream receives a portion of the working fluid and supplies the portion of the working fluid to the gas bearing of the compressor. A method of supplying lubricant to a gas bearing of a compressor in a heat transfer circuit includes compressing and further heating at least a portion of the working fluid heated in the evaporator, and supplying the compressed and further heated working fluid to the gas bearing of the compressor. A method of the supplying lubricant to a gas bearing of a compressor in a heat circuit includes generating compressed gaseous working fluid within a lubricant stream.

A heat pump system and a control method therefor. The heat pump system includes a compressor; an indoor heal exchanger; an outdoor heat exchanger, including a first heat exchange portion and a second heat exchange portion, wherein a flow path switching device is provided between the first heat exchange portion and the second heat exchange portion to disconnect or communicate the first heat exchange portion and the second heat exchange portion; a first four-way valve; and a second four-way valve, configured to enable a high-temperature refrigerant to be input into the first heat exchange portion in a heating mode, so as to enable the heat pump system to operate in a heating and deicing mode.