Thermal storage system

Abstract

Apparatus and method for efficiently storing thermal energy, in particular thermal energy transferred from a concentrated solar energy receiver. The apparatus consists of a collection of modular thin walled tube pressure vessels enclosing solid sensible heat thermal storage elements. The high temperature solid is separated from the thin wall by thermal insulation and two thin gaps that carry the cold in and cold out high-pressure working fluids. Hot in and hot out working fluids circulate in counter flow channels within the solid sensible heat thermal storage elements. The solar receiver can also be modular to match the thermal storage elements, facilitating manufacturing and on site assembly. The design enables scalable thermal storage and concurrent thermal charging and discharging with no circuit switching between charge and discharge.

1 . A method of efficiently storing thermal energy using sensible heat storage in solid material comprising:
 a) providing multiple thin walled pressure vessels containing pressurized working fluids,   b) providing solid thermal storage material contained within said pressure vessels,   c) providing thermal transfer channels within said solid thermal storage material,   d) providing means to couple said thermal storage material to a thermal charging source,   e) providing means to couple said thermal storage material to a thermal discharging sink,   f) transmitting the concentrated thermal energy from the thermal source, to said solid thermal storage material using a working fluid circuit,   g) transmitting the concentrated thermal energy from the solid thermal storage material, to said thermal sink using a second working fluid circuit,   whereby concentrated thermal energy can be modularly stored and some used and some stored for later use.   
     
     
         2 . The method of  claim 1 , wherein:
 The thin walled pressure vessels are made of steel.   
     
     
         3 . The method of  claim 1 , wherein:
 The solid thermal storage material is graphite.   
     
     
         4 . The method of  claim 1 , wherein:
 The working fluids are pressurized helium gas.   
     
     
         5 . The method of  claim 1 , wherein:
 The working fluids are pressurized argon gas.   
     
     
         6 . The method of  claim 1 , wherein:
 the thermal charging source is a solar receiver.   
     
     
         7 . The method of  claim 1 , wherein:
 the thermal charging sink is a power block.   
     
     
         8 . The method of  claim 1 , wherein:
 the thermal charging sink uses process heat.   
     
     
         9 . The method of  claim 1 , wherein:
 the thermal charging source is multiple modular solar receivers, each charging one or more pressure vessel thermal storage modules.   
     
     
         10 . The method of  claim 1 , further comprising:
 a) providing thermal insulation between the thermal storage material and the pressure vessel wall,   b) providing cooling channels between the thermal insulation and the pressure vessel wall,   c) coupling the cold in and cold out working gas connections to said cooling channels,   whereby the pressure vessel wall is cooled by the working fluids.   
     
     
         11 . A thermal storage apparatus for efficiently storing thermal energy using sensible heat storage in solid material comprising:
 a) multiple thin walled pressure vessels containing pressurized working fluids,   b) solid thermal storage material contained within said pressure vessels,   c) thermal transfer channels within said solid thermal storage material,   d) means to couple said thermal storage material via said heat transfer channels to a thermal charging source,   e) means to couple said thermal storage via said heat transfer channels to a thermal discharging sink,   whereby concentrated thermal energy can be modularly stored and some used and some stored for later use.   
     
     
         12 . The apparatus of  claim 11 , wherein:
 The thin walled pressure vessels are made of steel.   
     
     
         13 . The apparatus of  claim 11 , wherein:
 The solid thermal storage material is graphite.   
     
     
         14 . The apparatus of  claim 11 , wherein:
 The working fluids are pressurized helium gas.   
     
     
         15 . The apparatus of  claim 11 , wherein:
 The working fluids are pressurized argon gas.   
     
     
         16 . The apparatus of  claim 11 , wherein:
 the thermal charging source is a solar receiver.   
     
     
         17 . The apparatus of  claim 11 , wherein:
 the thermal charging sink is a power block.   
     
     
         18 . The apparatus of  claim 11 , wherein:
 the thermal charging sink uses process heat.   
     
     
         19 . The apparatus of  claim 11 , wherein:
 the thermal charging source is modular solar receivers, each charging one or more pressure vessel thermal storage modules.   
     
     
         20 . The apparatus of  claim 11 , further comprising
 a) thermal insulation between the thermal storage material and the pressure vessel wall,   b) cooling channels between the thermal insulation and the pressure vessel wall,   c) cold in and cold out working gas connections to said cooling channels,   whereby the pressure vessel wall is cooled by the working fluids.