The present invention provides a refrigerating machine oil containing an ester base oil obtained from pentaerythritol and mixed fatty acids of a fatty acid having 8 carbon atoms and a fatty acid having 9 carbon atoms, wherein a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, of the ester base oil is 1.06 to 1.20, and used with a mildly flammable hydrofluorocarbon refrigerant.

The present invention relates to a refrigerant composition, including trifluoroiodomethane (CF.sub.3I); 1,1,1,2-tetrafluoropropene (HFO-1234yf); difluoromethane (HFC-32); and carbon dioxide (CO.sub.2), for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-404A.

The present invention provides a refrigerating machine oil comprising: a lubricating base oil; and 40 mass % or less of a polymer, based on a total amount of the refrigerating machine oil, the polymer having a structural unit represented by the following formula (I) and a weight average molecular weight of from 500 to 100000.

##STR00001##

[In formula (I), R.sup.a, R.sup.b and R.sup.c each independently represents a hydrogen atom or a hydrocarbon group, and R.sup.d represents an oxygen-containing organic group or a C.sub.1-18 hydrocarbon group.]

Provided herein are compositions comprising at least one estolide compound of formula: ##STR00001##
in which n is an integer equal to or greater than 0; m is an integer equal to or greater than 1; R.sub.1, independently for each occurrence, is selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; R.sub.2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R.sub.3 and R.sub.4, independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. Also provided are uses of the compositions described herein.

The working fluid composition for a refrigerating machine of the invention is characterized by comprising an ester of a polyhydric alcohol and a fatty acid with a content of a C5-C9 branched fatty acid of 50-100% by mole, and a fluoropropene refrigerant and/or trifluoroiodomethane refrigerant. The refrigerating machine oil of the invention is characterized by comprising an ester of a polyhydric alcohol and a fatty acid with a content of a C5-C9 branched fatty acid of 50-100% by mole, and by being used together with a fluoropropene refrigerant and/or trifluoroiodomethane refrigerant.

A refrigerator oil according to one embodiment of the present invention contains: a base oil containing an oxygen-containing organic compound; a polyphosphate ester compound; and a metal salt of an organic carboxylic acid having 6 to 60 carbon atoms.

Environmentally friendly refrigerant blends utilizing refrigerants including 2,3,3,3-tetrafluoropropene (HFO-1234yf), difluoromethane (HFC-32), and 1,1-difluoroethane (HFC-152a). The blends have low GWP, low toxicity, and low flammability with low temperature glide for use in a hybrid, mild hybrid, plug-in hybrid, or full electric vehicles for thermal management (transferring heat from one part of the vehicle to the other) of the passenger compartment providing air conditioning (A/C) or heating to the passenger cabin.

The use of a refrigerant in organic Rankine cycle systems including at least one hydrofluoroolefin, having at least four carbon atoms represented by the formula (I) R1CHCHR2 in which R1 and R2 independently represent alkyl groups having from 1 to 6 carbon atoms, substituted with at least one fluorine atom, optionally with at least one chlorine atom.

This disclosure is directed to an additive package for a lubricant composition that provides improved compatibility with fluoropolymer seals. The additive package comprises a seal compatibility additive. The disclosure is also directed to a lubricant composition comprising a base oil and a seal compatibility additive. The seal compatibility additive improves the compatibility with fluoropolymer seals of the resultant lubricant composition.

A method and system for lubricating at least one moving part with a lubricating medium includes a chamber configured to house at least one moving part, a lubricant reservoir configured to house a liquid lubricant, a gas reservoir configured to house a gas, and a controller configured to supply a first amount of the gas in the form of bubbles to a second amount of the liquid lubricant to entrain the bubbles of gas in the liquid lubricant. The controller is also configured to regulate proportions of the liquid lubricant and the gas as a function of at least one operating condition, including at least one of pressure, temperature, and flow rate, a solubility relationship between the liquid lubricant and the gas, and a size of the bubbles of gas, and supply the liquid lubricant with entrained bubbles of gas to at least one moving part.