Esters as Cooling and Insulating Fluids for Transformers
AssigneeFuchs Petrolub SE
InventorsJürgen O. Metzger, Rolf Luther, Angela Robben, Gunther Kraft
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Abstract
The invention relates to compositions including esters of polyvalent alcohols that are esterified with fatty acids, partially unsaturated, from plant oils, and to the use thereof as cooling and insulating fluids for transformers.
Claims19
-18. (canceled)
An electrical power engineering unit provided with a dielectric insulation fluid, wherein the insulation fluid is a composition comprising or consisting of esters of general formula I,
- where
- R=methyl, ethyl, propyl, isopropyl or mixtures thereof, and
- R1=at least 30% linear saturated acid groups with 8 or 10 or 8 and 10 C atoms,
- R2=at least 20% acid groups with 14 to 22 C atoms comprising one or more double bonds, wherein more than 90% of the residues R2 comprise 18 C atoms and a double bond and optionally
- R3=0 to at most 20% linear saturated acid groups with 14 to 22 C atoms, and optionally
- R4=0 to at most 20% other acid groups apart from R1, R2 and optionally R3, wherein the residues R1 and R2 are at a numerical ratio of R1 to R2 from 1:1 to 5:1, and wherein the esters are mixed esters, in which the acid groups R1 and R2 and optionally R3 and optionally R4 of an alcohol residue are present in random distribution, and the mixed esters are obtainable from alcohols
- by a combined reaction with two or more different acids of the above-mentioned acid groups.
A method of using a composition as a dielectric insulation fluid in electrical power engineering units, wherein the composition comprises of esters of general formula I,
- and wherein,
- R=equals methyl, ethyl, propyl, isopropyl or mixtures thereof, and
- R1=at least 30% linear saturated acid groups with 8 or 10 or 8 and 10 C atoms, and
- R2=at least 20% acid groups with 14 to 22 C atoms comprising one or more double bonds, wherein more than 90% of the residues R2 comprise 18 C atoms and a double bond and optionally
- R3=0 to at most 20% linear saturated acid groups with 14 to 22 C atoms, and optionally
- R4=0 to at most 20% other acid groups apart from R1, R2 and optionally R3, wherein the residues R1 and R2 are in a numerical ratio of R1 to R2 from 1:1 to 5:1 and, wherein the esters are mixed esters in which the acid groups R1 and R2 and optionally R3 and optionally R4 of an alcohol residue are present in random distribution, and the mixed esters are obtainable from alcohols
- by a combined reaction with two or more different acids of the above-mentioned acid groups.
Dependencies are inferred from the claim text.