Phase change material for heat exchange fluid/coolant
This disclosure relates generally to micellar emulsions. This disclosure relates more particularly to micellar emulsions useful as thermal management fluids, methods for preparing such emulsions, and methods of using such emulsions.
1 . A method for removing thermal energy comprising:
passing a thermal management fluid in the form of an emulsion over a surface, wherein the thermal management fluid comprises
an aqueous carrier fluid; and
a dispersion of micelles within the aqueous carrier fluid, wherein each micelle comprises a solid hydrophobic core particle comprising a phase change material, wherein the phase change material is paraffin, and one or more surfactants forming a micellar shell around the solid hydrophobic core particle, wherein a weight ratio of the amount of phase change material to an amount of surfactants is in a range of 1 to 10; wherein the micelles have a mean particle size diameter in a range of about 0.1 μm to about 1 μm, wherein a micellar size distribution d10 is no less than 80% of d50 and d90 is no more than 120% of d50, and wherein the phase change material has a melting point in a range of 35° C. to 100° C.;
wherein the emulsion has a heat capacity in a range of about 10 J/gK to about 35 J/gK; and
absorbing thermal energy in the thermal management fluid from the surface.
2 . The method of claim 1 , wherein the surface has an elevated temperature compared to a temperature of the thermal management fluid.
3 . The method of claim 1 , wherein the surface is a surface of an electrical component.
4 . The method of claim 1 , wherein the method further comprises producing the thermal energy by a chemical reaction.
5 . The method of claim 1 , wherein the method further comprises producing the thermal energy by operating an electrical component.
6 . The method of claim 5 , wherein the electrical component is selected from a battery pack, a capacitor, a fuel cell, a motor, or a computer.
7 . The method of claim 5 , wherein passing the thermal management fluid over the surface comprises circulating the thermal management fluid through a thermal management circuit associated with the electrical component.
8 . The method of claim 5 , wherein passing the thermal management fluid over the surface comprises submerging the electric component in the thermal management fluid.
9 . The method of claim 1 , wherein absorbing the thermal energy comprises chilling the thermal management fluid.
10 . The method of claim 1 , wherein the method further comprising removing the thermal energy that has accumulated in the thermal management fluid.
11 . The method of claim 1 , wherein the thermal management fluid has a thermal conductivity in the range of about 0.05 W/mK to about 1 W/mK.
12 . The method of claim 1 , wherein the emulsion has a kinematic viscosity of about 3 to about 40 cSt.
13 . The method of claim 1 , wherein less than 5 wt % of the one or more emulsifiers surfactants is present in the aqueous solution in an unbound state, based on a total weight of the emulsion.
14 . The method of claim 1 , wherein the phase change material is 1-cyclohexylooctadecane, 4-heptadacanone, quinone, benzamide, or a mixture thereof.
15 . The method of claim 1 , wherein the micelles comprise one phase change material.
16 . The method of claim 1 , wherein the phase change material is present in the emulsion in an amount of about 1 wt % to about 70 wt % based on a total weight of the emulsion.
17 . The method of claim 1 , wherein the one or more surfactants is selected from the group consisting from molecules having the structure hydrocarbyl group-aryl group-polyether group.