High-temperature thermal storage device with induction heating and molten metal, and thermal storage-composite system

Abstract

A high-temperature thermal storage device has a crucible, an induction heating device, a tubular duct in which a liquid and/or gaseous heat carrier flows, and an electrically conductive storage medium filled into the crucible that fills the crucible at least partially. The induction heating device, when electric energy is applied, heats the storage medium. The tubular duct passes at least partially through the storage medium. The storage medium is a molten metal and the thermal storage device has an operating temperature exceeding 700° C. The thermal storage device readily provides steam, be it saturated steam or superheated steam, fulfilling all parameters required for the operation of a conventional thermal power station.

What is claimed is: 
     
         1 . A high-temperature thermal storage device comprising:
 a crucible;   an induction heating device;   a tubular duct in which a heat carrier flows that is liquid and/or gaseous;   an electrically conductive storage medium that is contained in the crucible and that fills the crucible at least partially;   wherein the induction heating device, when electric energy is applied, heats the storage medium; and   wherein the tubular duct passes at least partially through the storage medium.   
     
     
         2 . The high-temperature thermal storage device according to  claim 1 , wherein the storage medium is a molten metal. 
     
     
         3 . The high-temperature thermal storage device according to  claim 1 , wherein the storage medium has a melting temperature exceeding 500° C. 
     
     
         4 . The high-temperature thermal storage device according to  claim 1 , wherein the storage medium ( 9 ) is liquid at a temperature of 700° C. 
     
     
         5 . The high-temperature thermal storage device according to  claim 1 , wherein the high-temperature thermal storage device is charged by the induction heating device and discharged via the heat carrier passing through the tubular duct. 
     
     
         6 . The high-temperature thermal storage device according to  claim 1 , including thermal insulation. 
     
     
         7 . The high-temperature thermal storage device according to  claim 1 , comprising a heat exchanger integrated in the tubular duct, wherein the heat exchanger transfers heat from the storage medium to the heat carrier flowing in the tubular duct ( 7 ). 
     
     
         8 . The high-temperature thermal storage device according to  claim 1  in the form of a modified induction melting furnace. 
     
     
         9 . A thermal storage composite system comprising:
 a first thermal storage device;   a second thermal storage device;   wherein the first thermal storage device is charged and/or discharged via a heat carrier that is liquid or gaseous; and   wherein at least a partial flow of the heat carrier, after having passed through the first thermal storage device, passes through the second thermal storage device to be heated up further.   
     
     
         10 . The thermal storage composite system according to  claim 9 , wherein the second thermal storage device is a high-temperature thermal storage device comprising a crucible; an induction heating device; a tubular duct in which a heat carrier flows that is liquid and/or gaseous; an electrically conductive storage medium that is contained in the crucible and that fills the crucible at least partially; wherein the induction heating device, when electric energy is applied, heats the storage medium and wherein the tubular duct passes at least partially through the storage medium. 
     
     
         11 . The thermal storage composite system according to  claim 9 , wherein the partial flow of the heat carrier is fed to the second thermal storage device via controllable valves and is superheated to a superheated partial flow. 
     
     
         12 . The thermal storage composite system according to  claim 12 , further comprising a mixing station, wherein the superheated partial flow is mixed with the residual flow of the heat carrier in the mixing station. 
     
     
         13 . The thermal storage composite system according to  claim 9 , wherein the first thermal storage device has a lower operating temperature than the second thermal storage device. 
     
     
         14 . A process for operating a thermal storage composite system according to  claim 9 , comprising the steps of:
 Charging and/or discharged the first thermal storage device by a heat carrier that is liquid or gaseous;   Charging the second thermal storage device by electric energy;   Discharging the second thermal storage device by a heat carrier that is liquid or gaseous.   
     
     
         15 . The process according to  claim 14 , wherein the electric energy that charges the second thermal storage device is renewably generated electric energy and/or electric energy available on a spot market. 
     
     
         16 . The process according to  claim 14 , comprising increasing or lowering an output of the induction heating device to make available demand energy to a power grid. 
     
     
         17 . The process according to  claim 14 , comprising providing several of said second thermal storage device and connecting said several thermal storage devices in series and/or in parallel. 
     
     
         18 . The process according to  claim 17 , wherein said several thermal storage devices each have different operating temperatures. 
     
     
         19 . The process according to  claim 17 , wherein said several second thermal storage devices contain a storage medium that is a molten metal and wherein eh molten metals of said second thermal storage devices are different.