A method for operating a refrigerant circulation system comprising a compressor, a condenser, an expansion mechanism, and an evaporator connected in this order with piping, wherein a refrigerant comprising trifluoroiodomethane is used as a refrigerant; a refrigerating machine oil comprising, as a base oil, a polyolester synthesized from a polyhydric alcohol and fatty acids, with a proportion of a fatty acid having 9 carbon atoms in the fatty acids being 65 mol % or less is used as a refrigerating machine oil; and a temperature of an entire area of the refrigerant circulation system is kept at 160° C. or lower.

Compositions, systems and methods for introducing lubricants, and additives, that are designed to work with environmentally friendly refrigerants into vehicle heat management systems including passenger compartment air conditioning (A/C) systems are disclosed. Methods for charging lubricants and specific additives using environmentally desirable (low GWP) refrigerant or refrigerant blend compositions into an environmentally friendly system, such as a system that uses HFO-1234yf, are also disclosed.

The present invention provides a refrigerating machine oil containing a lubricating base oil, a dialkyl hydrogen phosphite having two alkyl groups having 1 to 12 carbon atoms in the molecule, and an epoxy compound.

A lubricating oil composition for refrigerating machines contains a base oil and an additive in a form of a hydrocarbon compound having a biphenyl structure or a stilbene structure. When the present lubricating oil composition for refrigerating machines is used in refrigerating equipment such as an open-type automobile air-conditioner, an electric automobile air-conditioner, a gas heat pump, other air-conditioning equipment, a refrigerating machine, a vending machine, a showcase, a water-heating system and a refrigerating/heating system, it is possible to detect the leakage of a refrigerant with a long-lasting stability. Therefore, when an unsaturated chlorofluorocarbon refrigerant with a poor stability is used in the above-listed equipment, the present lubricating oil composition for refrigerating machines is significantly advantageous.

The present invention provides a working fluid composition for a refrigerating machine, comprising: a refrigerating machine oil comprising, as a base oil, a mixed ester of (A) a complex ester obtainable by synthesis of at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a C6-C12 polybasic acid, and a C4-C18 monohydric alcohol or a C4-C18 monocarboxylic fatty acid, and (B) a polyol ester obtainable by synthesis of from at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol, and a C4-C18 monocarboxylic fatty acid, in a mass ratio of (A) the complex ester/(B) the polyol ester of 5/95 to 95/5; and tetrafluoropropene as a refrigerant, wherein a refrigerant dissolved viscosity, at a temperature of 80° C. and an absolute pressure of 1.6 MPa, is 1.5 mm.sup.2/s or more.

The present invention relates to a refrigerant composition, including difluoromethane (HFC-32), pentafluoroethane (HFC-125), and trifluoroiodomethane (CF.sub.3I) for use in a heat exchange system, including air conditioning and refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-410A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-410A.

A composition including: trifluoroethylene; pentafluoroethane; and at least one compound C chosen from the group constituted by difluoromethane, 1,1,1-trifluoropropene, trifluoroethane, 1,1,1,2-tetrafluoroethane, monofluoroethane, 1,1,1,4,4,4-hexafluorobut-2-ene, 3,3,4,4,4-pentafluorobut-1-ene, 2,4,4,4-tetrafluorobut-1-ene, 1,1,1,3,3-pentafluoropropane, 2,3,3,3-tetrafluoropropene, 1,1,2,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,3,3-pentafluorobutane, butane, 1,1,1,2,3,3,3-heptafluoropropane, 1-chlorotrifluoropropene, 2-methylbutane, pentane, propane, and mixtures thereof. Also, the uses thereof in refrigeration, air conditioning and heat pumps.

In an aspect, the present invention provides a refrigerating machine oil comprising a poly(meth)acrylate as a base oil, wherein the poly(meth)acrylate comprises a hydrogenated poly(meth)acrylate, a content of a unit having a carbon-carbon double bond present at a terminal in the poly(meth)acrylate is 6% by mole or less relative to total units constituting the poly(meth)acrylate, and a kinematic viscosity at 40° C. of the hydrogenated poly(meth)acrylate is 1 to 1000 mm2/s, the refrigerating machine oil being used with a refrigerant comprising a refrigerant selected from difluoromethane, a mixture of difluoromethane and pentafluoroethane, a mixture of difluoromethane, pentafluoroethane, and 1, 1, 1, 2-tetrafluoroethane, a mixture of pentafluoroethane, 1, 1, 1, 2-tetrafluoroethane, and 1, 1, 1-trifluoroethane, an unsaturated hydrofluorocarbon, a hydrocarbon, and carbon dioxide.

A composition comprising an orthoester and an organosilane, and in some embodiments, a metal deactivator, antioxidant, lubricant and/or corrosion inhibitor. Also, disclosed is use of the composition for use in increasing thermal conductivity of internal fluids in air conditioning and refrigerant systems.

The present invention relates to compositions comprising at least one fluoroolefin, HFC-32, and an effective amount of at least one inhibitor. The stabilized compositions may be useful in cooling and heating apparatus, such as refrigeration, air-conditioning, chillers, and heat pumps, as well as in applications as foam blowing agents, solvents, aerosol propellants, fire extinguishants, and sterilants.