Low viscosity mono-unsaturated acid-containing oil-based dielectric fluids
Disclosed herein are a dielectric fluid composition and a method thereof. Also disclosed are viscosity modifiers and a method of lowering the viscosity of an oil-based dielectric fluid. The composition includes an oil with a high mono-unsaturated fatty acid content and one or more fatty acid alkyl esters, each having a fatty acid and an alkyl moiety, wherein the alkyl moiety of the fatty acid alkyl esters has 1 to 4 carbon atoms, and wherein both the oil and the fatty acid alkyl ester are in the range of 40%-60% v/v of the dielectric fluid composition. The viscosity modifier includes one or more fatty acid alkyl esters with an alkyl moiety and a fatty acid moiety, wherein the alkyl moiety has 1 to 4 carbon atoms. The method of lowering the viscosity includes blending the viscosity modifier and a vegetable oil-based dielectric fluid in a ratio of 40:60-60:40.
1. A dielectric fluid composition comprising:
an oil of a high mono-unsaturated fatty acid content wherein the mono-unsaturated fatty acid content of the oil is greater than 60%; and
one or more fatty acid alkyl esters, each having a fatty acid moiety and an alkyl moiety, wherein the alkyl moiety of the fatty acid alkyl esters has 1 to 4 carbon atoms and wherein the fatty acid moieties of the fatty acid alkyl esters are substantially homologous with the mono-unsaturated fatty acid content of the oil of the dielectric fluid composition and wherein about 60% or more of the fatty acid moieties of the fatty acid alkyl esters are derived from one or more mono-unsaturated fatty acids; and
wherein the oil is in the range of 40%-60% v/v of the dielectric fluid composition and the fatty acid alkyl ester is in the range of 40%-60% v/v of the dielectric fluid composition.
2. The dielectric fluid composition according to claim 1 , wherein the oil is selected from the group comprising: natural vegetable oil, synthetic vegetable oil, genetically modified vegetable oil, animal fat, bacterially derived oil, fungally derived oil and mixtures thereof.
3. A dielectric fluid composition according to claim 1 , wherein the viscosity of the dielectric fluid composition is <20 cSt at 40° C.
4. A dielectric fluid composition comprising:
an oil containing at least one mono-unsaturated fatty acid wherein the mono-unsaturated fatty acid content of the oil is greater than 60%; and
one or more fatty acid alkyl esters, each having a fatty acid moiety and an alkyl moiety, wherein the alkyl moiety of the fatty acid alkyl esters has 1 to 4 carbon atoms and wherein the fatty acid moieties of the fatty acid alkyl esters are substantially homologous with the mono-unsaturated fatty acid content of the oil of the dielectric fluid composition and wherein about 60% or more of the fatty acid moieties of the fatty acid alkyl esters are derived from one or more mono-unsaturated fatty acids; and
wherein the oil is in the range of 40%-60% v/v of the dielectric fluid composition and the fatty acid alkyl ester is in the range of 40%-60% v/v of the dielectric fluid composition, wherein the viscosity of the dielectric solution is greater than 0 and less than 20 cSt at 40° C.
5. A dielectric fluid composition according to claim 4 wherein the viscosity of the composition is between 1 and 20 cSt at 40° C.
6. A transformer having a housing which accommodates a transformer core/coil assembly and the dielectric fluid composition of claim 1 surrounding said core/coil assembly.
7. A viscosity modifier for oil-based dielectric fluids having a high mono-unsaturated fatty acid content, the viscosity modifier comprising one or more fatty acid alkyl esters having an alkyl moiety and a fatty acid moiety, wherein the alkyl moiety has 1 to 4 carbon atoms and wherein the fatty acid moieties of the fatty acid alkyl esters are substantially homologous with the mono-unsaturated fatty acid content of the oil of the dielectric fluid composition and wherein about 60% or more of the fatty acid moieties of the fatty acid alkyl esters are derived from one or more mono-unsaturated fatty acids.
8. The viscosity modifier according to claim 7 , wherein the mono-unsaturated fatty acids are selected from a group consisting of obtusilic, caproleic, lauroleic, linderic, myristoleic, physeteric, tsuzuic, palmitoleic, petroselinic, oleic, vaccenic, gadoleic, gondoic, cetoleic, erucic, and nervonic.