The present invention relates to a refrigerator oil for a mixed refrigerant containing less than 40% by mass of an unsaturated fluorinated hydrocarbon compound (HFO) on a basis of the whole amount of the mixed refrigerant, the refrigerator oil containing a base oil (P) including at least one selected from the group consisting of a polyvinyl ether (PVE), a polyalkylene glycol (PAG), a copolymer (ECP) of a poly(oxy)alkylene glycol or a monoether thereof and a polyvinyl ether, and a polyol ester (POE), with a hydroxy value of the base oil (P) being 15 mgKOH/g or less; and a refrigerator oil composition containing the foregoing refrigerator oil and a specified refrigerant.

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).

Compositions, methods, systems, and applications herein are directed to lubricant blends that balance solubility and viscosity of a refrigerant, where in some cases the lubricant blends herein help reduce solubility of a refrigerant. A lubricant blend includes a mixture of two or more different types of lubricants to reduce refrigerant solubility.

A refrigeration cycle apparatus that is able to suppress a decrease in capacity when a refrigerant that contains at least 1,2-difluoroethylene is used is provided. In an air conditioner (1) including a refrigerant circuit (10) in which a compressor (21), an outdoor heat exchanger (23), an outdoor expansion valve (24), a liquid-side connection pipe (6), an indoor heat exchanger (31), and a gas-side connection pipe (5) are connected, a refrigerant containing at least 1,2-difluoroethylene is used, a pipe outer diameter of the liquid-side connection pipe (6) and a pipe outer diameter of the gas-side connection pipe (5) each are D.sub.0/8 inches (where, D.sub.0- inches is a pipe outer diameter of a connection pipe when refrigerant R32 is used), a range of the D.sub.0 of the liquid-side connection pipe (6) is 2D.sub.04, and a range of the D.sub.0 of the gas-side connection pipe (5) is 3D.sub.08.

The present invention relates to a cooling mixture comprising a fluorinated compound and a non-fluorinated compound, wherein the fluorinated compound is a hydrofluoroether and the non-fluorinated compound includes a carbonyl function, which has a flash point no lower than 23 C. and which is characterised by having low relative volatility. The present invention likewise relates to the use of such a mixture as a coolant in a heat-exchange device.

A refrigerator oil that is excellent in thermal stability and oxidation stability is provided. The refrigerator oil contains at least one compound selected from the group consisting of a polyvinyl ether compound, a polyoxyalkylene glycol compound, and a polyol ester compound and has a Hazen color number according to ASTM D1209-05 of 0 to 10.

A vapor compression system (20) has: a centrifugal compressor (22) having an inlet (40) and an outlet (42); and an electric motor (28) having a stator (30) and a rotor (32). A plurality of bearings (36) support the rotor. A refrigerant charge comprises a base refrigerant and one or more oils. The one or more oils are present at a total concentration of 80-5000 parts per million (ppm) by weight.

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

A refrigeration cycle apparatus including a heat exchanger can decrease the material cost. An air conditioning apparatus (10) that is a refrigeration cycle apparatus includes a flammable refrigerant containing at least 1,2-difluoroethylene, an outdoor heat exchanger (23), and an indoor heat exchanger (27). One of the outdoor heat exchanger (23) and the indoor heat exchanger (27) is an evaporator that evaporates the refrigerant, and the other one is a condenser that condenses the refrigerant. The outdoor heat exchanger (23) and the indoor heat exchanger (27) each are a heat exchanger that includes metal plates (19) serving as a plurality of fins made of aluminum or an aluminum alloy, and flat tubes (16) serving as a plurality of heat transfer tubes made of aluminum or an aluminum alloy, and that causes the refrigerant flowing inside the flat tubes (16) and the air flowing along the metal plates (19) to exchange heat with each other. The refrigerant repeats a refrigeration cycle by circulating through the outdoor heat exchanger (23) and the indoor heat exchanger (27).

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 at least 1,2-difluoroethylene.