The present invention relates to heat transfer compositions comprising refrigerant, lubricant and stabilizer, wherein the refrigerant comprises from about 10% by weight to 100% by weight of trifluoroiodomethane (CF.sub.3I), and wherein said lubricant comprises polyol ester (POE) lubricant and/or polyvinyl ether (PVE) lubricant, and wherein said stabilizer comprises at least one stabilizing compound according to the following Formula I:

##STR00001##

where each R.sup.1 is independently an epoxy terminated ethoxy, propoxy or butoxy group.

The lubricating oil composition for a refrigerator according to the present invention is a lubricating oil composition for a refrigerator containing a base oil containing a low-viscosity base oil component having added thereto a polyoxyalkylene glycol compound having a kinetic viscosity at 100° C. that is higher than the low-viscosity base oil component, and the base oil has a kinetic viscosity at 100° C. of 2.4 to 25 mm.sup.2/s and a ratio (Mw/Mn) of a weight average molecular weight (Mw) and a number average molecular weight (Mn) of 1.3 to 13.

The lubricating oil composition for a refrigerator of the present invention is a lubricating oil composition for a refrigerator that is used in combination with a refrigerant containing at least one fluorine-containing organic compound selected from compounds represented by the following molecular formula (A):

C.sub.pF.sub.rR.sub.s  (A)

wherein R represents Cl, Br, I, or H; p represents an integer of from 2 to 6; r represents an integer of from 1 to 12; and s represents an integer of from 0 to 11, provided that the molecule contains at least one carbon-carbon unsaturated bond, and the lubricating oil composition for a refrigerator contains a base oil and a cyclic organic compound having a cyclic hydrocarbon structure and having one or more non-conjugated double bond in a cyclic structure or a side chain thereof.

The lubricating oil composition for a refrigerator of the present invention is a lubricating oil composition for a refrigerator that is used in combination with a refrigerant containing at least one fluorine-containing organic compound selected from compounds represented by the following molecular formula (A):

C.sub.pF.sub.rR.sub.s  (A)

wherein R represents Cl, Br, I, or H; p represents an integer of from 2 to 6; r represents an integer of from 1 to 12; and s represents an integer of from 0 to 11, provided that the molecule contains at least one carbon-carbon unsaturated bond, and the lubricating oil composition for a refrigerator contains a base oil and a cyclic organic compound having a cyclic hydrocarbon structure and having one or more non-conjugated double bond in a cyclic structure or a side chain thereof.

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.

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.

The present invention is able to provide a lubricating oil composition for compression refrigerating machine having excellent thermal/chemical stability even when used for a compression refrigerating machine using a saturated fluorinated hydrocarbon refrigerant having a low carbon number and a low global warming potential, by using a refrigerant containing a saturated fluorinated hydrocarbon having from 1 to 3 carbon atoms, which uses, as a base oil, an oxygen-containing organic compound composed of at least one member selected from a polyoxyalkylene glycol, a polyvinyl ether, a copolymer of a poly(oxy)alkylene glycol and a polyvinyl ether, a copolymer of a poly(oxy)alkylene glycol monoether and a polyvinyl ether, and a polyol ester, each having a hydroxyl value of not more than 15 mgKOH/g.

The present invention is able to provide a lubricating oil composition for compression refrigerating machine having excellent thermal/chemical stability even when used for a compression refrigerating machine using a saturated fluorinated hydrocarbon refrigerant having a low carbon number and a low global warming potential, by using a refrigerant containing a saturated fluorinated hydrocarbon having from 1 to 3 carbon atoms, which uses, as a base oil, an oxygen-containing organic compound composed of at least one member selected from a polyoxyalkylene glycol, a polyvinyl ether, a copolymer of a poly(oxy)alkylene glycol and a polyvinyl ether, a copolymer of a poly(oxy)alkylene glycol monoether and a polyvinyl ether, and a polyol ester, each having a hydroxyl value of not more than 15 mgKOH/g.

A refrigeration cycle apparatus includes refrigerant circuits in which a high pressure shell compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected; a mixed refrigerant containing 1,1,2-trifluoroethylene and a refrigerant other than 1,1,2-trifluorothylene and circulating through the refrigerant circuits; and a refrigerating machine oil enclosed in the refrigerant circuits and adjusted such that 1,1,2-trifluoroethylene will be more soluble therein than the other refrigerant is.

The invention addresses a problem of providing a lubricating oil composition for refrigerators excellent in thermal stability for a refrigerant that contains difluoromethane (R32), trifluoroiodomethane (CF.sub.3I) and at least one compound (α) selected from saturated fluorinated hydrocarbon compounds (HFC) except difluoromethane (R32). The lubricating oil composition for refrigerators is used for a refrigerant containing difluoromethane (R32), trifluoroiodomethane (CF.sub.3I) and at least one compound (α) selected from saturated fluorinated hydrocarbon compounds (HFC) except difluoromethane (R32), and contains at least one kind of base oil selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of a poly(oxy)alkylene glycol or a monoether thereof and a polyvinyl ether and polyol esters, in which the hydroxyl value of the base oil is 15 mgKOH/g or less.