Thermal Storage Medium

Abstract

A heat storage medium has a solid heat storage area and a plurality of channels extending through the heat storage area between an inlet and an outlet. In one embodiment, there are electric heaters embedded in the heat storage area. A fluid flows through the channels to add or remove heat from the heat storage medium. A method of operating the heat storage medium is described.

1 . A heat storage medium for use with a fluid in storing heat energy, said storage medium comprising a three dimensional structure containing electric heaters embedded in said structure, said heaters being connected to a source of electricity to provide heat energy to said storage medium, said heat storage medium containing a plurality of passages connected to permit said fluid to flow through said passages to remove heat energy from said heat storage medium. 
   
   
       2 . A heat storage medium as claimed in  claim 1  wherein said three dimensional structure has a solid heat storage area and said heaters are embedded in said heat storage area. 
   
   
       3 . A heat storage medium as claimed in  claim 1  wherein said passages are channels extending through said heat storage medium. 
   
   
       4 . A heat storage medium as claimed in  claim 3  wherein said channels are high pressure channels. 
   
   
       5 . A heat storage medium as claimed in  claim 4  wherein said fluid is located in said channels and said fluid is a high pressure fluid. 
   
   
       6 . A heat storage medium as claimed in  claim 3  wherein said heaters heat said heat storage medium to a temperature exceeding 100° C. 
   
   
       7 . A heat storage medium as claimed in  claim 6  wherein said heaters heat said heat storage medium to a temperature ranging from substantially 200° C. to substantially 900° C. 
   
   
       8 . A heat storage medium as claimed in  claim 1  wherein said three dimensional structure has insulation on an outer surface thereof. 
   
   
       9 . A heat storage medium as claimed in  claim 3  wherein said solid heat storage area is made from materials selected from the group of steel, iron, rocks, soapstone, lava-rock, fire brick, alumina brick, magnesia brick, brick, ceramics and manufactured brick. 
   
   
       10 . A heat storage medium as claimed in  claim 3  wherein said solid heat storage area contains particulate material. 
   
   
       11 . A heat storage medium as claimed in  claim 1  wherein there is a controller to control said electric heaters, a temperature of said storage medium, the flow of fluid through said storage medium and a temperature of said fluid. 
   
   
       12 . A heat storage medium as claimed in  claim 1  wherein said fluid is water/steam. 
   
   
       13 . A heat storage medium as claimed in  claim 1  wherein said medium contains solid material that can withstand a broad range of temperature change without changing phase, repeated changes in temperature without breaking down and can receive and store heat energy. 
   
   
       14 . A heat storage medium as claimed in  claim 1  wherein said passages have a fluid inlet and a fluid outlet. 
   
   
       15 . A heat storage medium as claimed in  claim 1  wherein said three dimensional structure is a box. 
   
   
       16 . A heat storage medium for use with a fluid, said heat storage medium being used to store and supply heat energy, said heat storage medium comprising a heat storage area having a solid heat transfer medium therein, with passages extending through said heat storage medium, said passages being connected to permit said fluid to flow through said heat storage medium to charge or discharge said heat storage medium based on the temperature of said fluid relative to a temperature of said heat transfer medium. 
   
   
       17 . A heat storage medium as claimed in  claim 1  where there is a controller to determine the temperature of the heat transfer medium and of the fluid to control the flow of fluid through said passages. 
   
   
       18 . A method of storing heat energy in a heat storage medium, said method comprising embedding electric heaters in said heat storage medium connecting said heaters to a supply of electricity to provide heat energy to said heat storage medium and activating or deactivating said heaters as required, storing said heat energy in said heat storage medium, said heat storage medium containing a plurality of passages to receive a fluid and causing said fluid to flow through said passages to remove heat energy from said heat storage medium. 
   
   
       19 . A method as claimed in  claim 15  wherein said heat storage medium has a controller, said method including the steps of operating said controller to control said heaters, a flow of said fluid through said passages and a temperature of said heat storage medium and said fluid. 
   
   
       20 . A method as claimed in  claim 15  including the step of operating said heat storage medium at a temperature exceeding 100° C. 
   
   
       21 . A method as claimed in  claim 17  including the step of operating said heat storage medium at a temperature ranging from substantially 200° C. to substantially 900°.