High-temperature latent heat storage system using transportable heat pipes for versatile integration with emerging microreactors

Abstract

A heat pipe integrated thermal battery (“HITB”) is provided that may include a storage tank, a thermal storage medium within the storage tank, a guide tube extending within the storage tank and through at least one end of the storage tank, and a heat pipe configured to be movable within the guide tube. The heat pipe may be configured to discharge heat to and absorb heat from the thermal storage medium within the storage tank.

What is claimed is: 
     
         1 . A heat pipe integrated thermal battery (“HITB”) comprising:
 a storage tank; 
 a thermal storage medium within the storage tank; 
 a guide tube extending within the storage tank and through at least one end of the storage tank; and 
 a heat pipe configured to be movable within the guide tube, the heat pipe being configured to discharge heat to and absorb heat from the thermal storage medium within the storage tank. 
 
     
     
         2 . The HITB of  claim 1 , further comprising a heat pipe drive mechanism configured to move the heat pipe within the guide tube. 
     
     
         3 . The HITB of  claim 1 , wherein the guide tube comprises fins on a portion of the guide tube that extends outside the storage tank. 
     
     
         4 . The HITB of  claim 1 , wherein the guide tube comprises an end cap allowing access within the guide tube. 
     
     
         5 . The HITB of  claim 1 , further comprising a thermal interface within the guide tube, the thermal interface being between an inner surface of the guide tube and an external surface of the heat pipe. 
     
     
         6 . The HITB of  claim 5 , wherein the thermal interface comprises a sleeve disposed against the inner surface of the guide tube. 
     
     
         7 . The HITB of  claim 6 , wherein the sleeve comprises a porous metal. 
     
     
         8 . The HITB of  claim 1 , wherein the storage tank comprises a cylindrical tank comprising an inner wall, an outer wall, and an insulating liner between the inner wall and the outer wall. 
     
     
         9 . The HITB of  claim 8 , wherein the inner wall and the outer wall comprise stainless steel and wherein the insulating liner comprises a boron nitride coating. 
     
     
         10 . The HITB of  claim 1 , wherein the thermal storage medium comprises a metal alloy and wherein heat stored in the thermal storage medium is stored as latent heat of the metal alloy. 
     
     
         11 . The HITB of  claim 10 , wherein the metal alloy comprises an aluminum alloy. 
     
     
         12 . The HITB of  claim 1 , wherein the guide tube protrudes from a first end of the storage tank and protrudes from a second end of the storage tank opposite the first end of the storage tank. 
     
     
         13 . The HITB of  claim 12 , wherein when the heat pipe is moved to a first end of the guide tube, the heat pipe is configured to absorb heat and to transfer heat to the thermal storage medium, and wherein when the heat pipe is moved to a second end of the guide tube, the heat pipe is configured to absorb heat from the thermal storage medium and release heat from the guide tube. 
     
     
         14 . A thermal energy storage system comprising:
 a feed and drain tank comprising a heating element operable to melt a thermal storage medium to a molten state;   a heat pipe integrated thermal battery (“HITB”) comprising a storage tank, the storage tank operable to hold the thermal storage medium such that latent heat of the thermal storage medium may be stored in the HITB;   a thermal storage medium transport line connecting the feed and drain tank to the HITB; and   a pump configured to move the thermal storage medium from the feed and drain tank to the HITB and from the HITB to the feed and drain tank.   
     
     
         15 . The thermal energy storage system of  claim 14 , further comprising a HITB venting line connecting the HITB and the feed and drain tank, the HITB venting line being configured to vent gas from the HITB to the feed and drain tank. 
     
     
         16 . The thermal energy storage system of  claim 14 , further comprising:
 a HITB vacuum line connecting the pump to the HITB, the HITB vacuum line comprising a first valve; and   a feed and drain vacuum line connecting the pump to the feed and drain tank, the feed and drain vacuum line comprising a second valve,   wherein when the first valve is opened and the second valve is closed, a vacuum is applied to the HITB to move the thermal storage medium from the feed and drain tank to the HITB via the thermal storage medium transport line, and   wherein when the first valve is closed and the second valve is opened, a vacuum is applied to the feed and drain tank to move the thermal storage medium from the HITB to the feed and drain tank.   
     
     
         17 . A method for operating a heat pipe integrated thermal battery (“HITB”) comprising:
 charging the HITB, the charging comprising:
 moving a heat pipe through a guide tube of the HITB to a charging position; 
 absorbing heat into the heat pipe from a first external system and transferring heat from the heat pipe to a thermal storage medium in a storage tank of the HITB; 
 
 discharging the HITB, the discharging comprising:
 moving the heat pipe through the guide tube to a discharging position; 
 absorbing heat into the heat pipe from the thermal storage medium in the storage tank of the HITB and discharging heat from the heat pipe to a second external system. 
 
 
     
     
         18 . The method of  claim 17 , further comprising:
 prior to charging, filling the HITB with the thermal storage medium from a feed and drain tank.   
     
     
         19 . The method of  claim 17 , further comprising:
 emptying the thermal storage medium from the HITB to a feed and drain tank.   
     
     
         20 . The method of  claim 17 , wherein heat stored in the thermal storage medium is stored as latent heat of the thermal storage medium.