Heat transfer system
A heat transfer device, such as a heat exchanger, has dimensions and flow speed such that Reynolds number for the flow is in a range from 1 to 1000. The device uses a working fluid which is in a state of elastic turbulence. This enhances transfer of heat to or from the working fluid. In some embodiments the fluid is an emulsion with a disperse phase which changes between liquid and solid so that its latent heat of fusion contributes to the amount of heat carried by the working fluid.
1 . A method of moving heat into or out of a flowing fluid, comprising:
pumping the flowing fluid through a heat transfer device,
wherein the heat transfer device comprises a chamber for through flow of the flowing fluid,
wherein a chamber wall in contact with the flowing fluid is an interface through which heat energy is transferred to or from the flowing fluid,
wherein the chamber contains an array of spaced obstructions compelling the streamlines of the flowing fluid to repeatedly change direction in order to flow through gaps between the obstructions,
wherein the flowing fluid contains a solute which enables the flowing fluid to display elastic turbulence,
wherein a flow rate of the flowing fluid in the chamber is such that the flowing fluid is in a state of elastic turbulence,
wherein the viscosity of the flowing fluid, the flow rate of the flowing fluid within the chamber, and a width of the gaps between obstructions give a Reynolds number (Re) for the flowing fluid which is in a range from 1 to 1000, and
wherein the flowing fluid is an emulsion with a continuous phase which is a solution of the solute which enables the flowing fluid to display elastic turbulence and a suspended disperse phase which changes between solid and liquid at temperatures where the continuous phase is liquid.
2 . The method of claim 1 , wherein the heat transfer device is part of a heat exchange system comprising:
a second heat transfer device at a different location;
a pump; and
pipework connecting the pump and the heat transfer devices as a closed circuit containing the flowing fluid.
3 . The method of claim 1 , wherein the solute which enables the flowing fluid to display elastic turbulence is a polymer containing at least 5,000 monomer units in one or more linear polymer chains each containing at least 1000 monomer units, connected one to the next by a single covalent bond so that one monomer unit can rotate relative to adjoining monomer units.
4 . The method of claim 1 , wherein the solute which enables the flowing fluid to display elastic turbulence is a polymer with a molecular weight above 10 6 Daltons.
5 . The method of claim 4 , where the polymer contains a linear chain of at least 5000 monomer units.
6 . The method of claim 5 , wherein the polymer is a polyacrylamide or polyacrylamide derivative.
7 . The method of claim 1 , wherein the solute which enables the flowing fluid to display elastic turbulence is a worm-like micellar surfactant system comprising one or more aggregating molecule species.
8 . The method of claim 1 , wherein the chamber has a volume of at least 50 ml.
9 . The method of claim 1 , wherein the continuous phase is an aqueous solution of the solute containing not more than 5% by weight of the solute which enables the flowing fluid to display elastic turbulence.
10 . The method of claim 1 , wherein the suspended disperse phase melts above −80° C. and below 150° C.
11 . The method of claim 1 , wherein the continuous phase is an aqueous solution of the solute which enables the flowing fluid to display elastic turbulence.
12 . The method of claim 1 , wherein the suspended disperse phase comprises one or more aliphatic organic compounds containing alkyl groups of at least 12 carbon atoms.
13 . The method of claim 12 , wherein the suspended disperse phase comprises one or more saturated alkanes of at least 14 carbon atoms.
14 . The method of claim 1 , wherein the spaced obstructions extend across the chamber from the interface to an opposing chamber wall spaced from the interface.