Two-phase thermal storage means and method

Claim 1

A two phase thermal storage method comprising the steps of: providing a temperature-sensitive phase transformation storage material having a phase-dependent variable density; contacting an immiscible heat transfer liquid with said storage material; storing heat in the liquid phase of said storage material by heating said heat transfer liquid to a temperature above the temperature of storage material contacting said heat transfer liquid whereby heat stored in said storage material is increased; and removing said stored heat by cooling said heat transfer liquid to a temperature below the liquid-to-solid phase-transformation temperature of said storage material whereby at least a portion of said storage material is solidified at the interface with said heat transfer fluid, and removing solidified storage material from said interface by bouyancy forces; wherein said heat transfer liquid may be cooled by circulating a quantity of heat transfer liquid from the interface with said storage material through a heat exchange relationship with a coolant and returning said quantity of liquid to said interface, and further wherein said heat transfer liquid may be heated by circulating a quantity of the heat transfer liquid from the interface with said storage material through heat exchange relationship with a source of heat and returning said quantity of liquid to said interface.