Thermal Energy Storage System
Various embodiments include a thermal storage system for storing energy in a graphite thermal storage structure and a thermal shutter assembly configured to control the transmission of heat from the graphite thermal storage structure to a thermal energy receiver, such as a heat exchanger or material processing crucible. A thermal storage block, which may be made of graphite, may be isolated by insulation except for the thermal shutter assembly. Energy may be stored in the graphite thermal storage block by applying energy to the block to raise its temperature to maximum operation temperature. Stored energy may then be harvested in a controlled manner by a control system actuating the thermal shutter to expose the thermal energy receiver to thermal radiation.
1 . A method for controlling a thermal storage system, comprising:
applying energy to a graphite thermal storage block so as to store energy by raising the temperature of the graphite thermal storage block; and
actuating a thermal shutter to control an amount of radiant thermal energy emitted by the graphite thermal storage block that is exposed to a thermal energy receiver.
2 . The method of claim 1 , wherein actuating the thermal shutter to control the amount of radiant thermal energy emitted by the graphite thermal storage block that is exposed to a thermal energy receiver comprises actuating the thermal shutter to achieve a temperature of the thermal energy receiver between a maximum temperature and a minimum temperature.
3 . The method of claim 2 , wherein actuating the thermal shutter to control the amount of radiant thermal energy emitted by the graphite thermal storage block that is exposed to a thermal energy receiver comprises actuating the thermal shutter to control an amount of radiant thermal energy per unit time reaching the thermal energy receiver.
4 . The method of claim 1 , wherein the thermal energy receiver is a steam generator, the method further comprising controlling a feedwater flow rate into the steam generator in combination with actuating the thermal shutter to control an amount of radiant thermal energy per unit time reaching the thermal energy receiver so as to maintain steam produced by the steam generator at a target enthalpy or within a target range of enthalpies.
5 . A method for controlling a thermal storage system, comprising:
applying energy to a plurality of graphite thermal storage blocks within a stack of graphite thermal storage blocks positioned within a chamber so as to store energy by raising the temperature of the graphite thermal storage blocks; and
controlling an actuator to raise or lower the stack of graphite thermal storage blocks so as to position at least one graphite storage block within an exposure zone within the chamber to expose a thermal energy receiver to thermal energy emitted by the at least one graphite thermal storage block.