Thermal storage system
A thermal storage composition is defined by a polymer having thermally responsive absorption or passage capabilities based on an Upper Critical Solution Temperature (UCST) or Lower Critical Solution Temperature (LCST), and a sorbent in fluidic communication with the polymer. A fluid such as water conveys thermal energy between the polymer and the sorbent based on an identified target temperature that acts as a thermostat for synergistic fluid release and transfer between the polymer and sorbent that stores and releases heat energy in a cyclic manner. The composition includes a synergistic integration of a sorbent and selectively hydrophilic polymer to alternately hydrate according to a target temperature based on the UCST of the water/sorbent combination.
1. A thermal storage composition, comprising:
a polymer having thermally responsive fluidic capabilities based on an upper critical solution temperature (UCST) or lower critical solution temperature (LCST), the polymer formed from poly-acrylic acid or polyethylene imine by introducing charged moieties into a polymer backbone to define a UCST in a range between 5° C.-40° C.;
a sorbent in fluidic communication with the polymer; and
a fluid sorbate for conveying thermal energy between the polymer and the sorbent, wherein the polymer changes from hydrophobic to hydrophilic for absorbing water at a temperature above the UCST, the water defining a sorbate.
2. The composition of claim 1 wherein the polymer is a thermo-responsive polymer adapted for absorbing the sorbate at a temperature above the UCST or below the LCST.
3. The composition of claim 2 wherein the sorbent releases the sorbate to the polymer at a temperature greater than the UCST.
4. The composition of claim 1 wherein the sorbent has a regeneration temperature based on the UCST for releasing the sorbate to the polymer at a temperature greater than the UCST.
5. The composition of claim 4 wherein the sorbent is a zeolite material adapted to adsorb water as the sorbate for thermal release at temperatures below the UCST.
6. The composition of claim 1 wherein the polymer is adapted as a gating mechanism defined by the UCST or LCST for sorbate transport through the polymer based on the temperature of the polymer.
7. The composition of claim 1 wherein thermal storage occurs as increased ambient temperatures above the UCST causes water released from the sorbent to be absorbed by the polymer.
8. The composition of claim 1 wherein thermal release occurs as decreased ambient temperature below the UCST causes water release from the hydrophilic polymer to migrate to the sorbent.
9. The composition of claim 8 wherein the sorbent retains the thermal energy indefinitely until thermal release resulting from the ambient temperature falling below the UCST.
10. A thermal storage composition, comprising:
a polymer having thermally responsive fluidic capabilities based on an upper critical solution temperature (UCST) or lower critical solution temperature (LCST), the polymer formed from insertion of hydrophobic moieties into a hydrogen-bonding polyacrylamide backbone by random copolymerization of acrylonitrile and acrylamide to define a UCST in a range between 5° C.-60° C.;
a sorbent in fluidic communication with the polymer; and
a fluid sorbate for conveying thermal energy between the polymer and the sorbent, wherein the polymer changes from hydrophobic to hydrophilic for absorbing water at a temperature above the UCST, the water defining a sorbate.