Thermal energy storage

Abstract

A thermal storage (TES) unit includes an encasement with inner and outer surfaces. The TES unit includes an internal cavity surrounded by the inner surface of the encasement and at least a fin disposed in the cavity. The fin separates the cavity into a plurality of sub-cavities and includes openings to provide communication between the sub-cavities. A phase change material (PCM) is to be disposed within the encasement. The PCM includes a threshold temperature T T , a first temperature range corresponding to a first phase of the PCM and a second temperature range corresponding to a second phase of the PCM. The fin increases thermal transfer efficiency of the thermal energy between external environment of the TES unit and PCM. The TES unit can be incorporated for heating and cooling applications.

1 . A thermal storage (TES) unit comprising:
 a encasement with inner and outer surfaces;   an internal cavity surrounded by the inner surface of the encasement; and   at least a fin disposed in the cavity, the fin separate the cavity into a plurality of sub-cavities, the fin includes openings to provide communication between the sub-cavities; and   a phase change material (PCM) to be disposed within the encasement, the PCM comprising a threshold temperature T T , a first temperature range corresponding to a first phase of the PCM and a second temperature range corresponding to a second phase of the PCM, wherein the fin increases thermal transfer efficiency of thermal energy between external environment of the TES unit and PCM.   
     
     
         2 . The unit of  claim 1  comprising first and second halves coupled together to form the encasement. 
     
     
         3 . The unit of  claim 2  wherein the external environment comprises a thermal transfer medium. 
     
     
         4 . The unit of  claim 3  wherein the thermal transfer medium comprises water. 
     
     
         5 . The unit of  claim 2  comprising an opening and a cap to facilitate filling of the encasement with PCM and sealing the encasement. 
     
     
         6 . The unit of  claim 5  wherein the external environment comprises a thermal transfer medium. 
     
     
         7 . The unit of  claim 6  wherein the thermal transfer medium comprises water. 
     
     
         8 . The unit of  claim 1  wherein the external environment comprises a thermal transfer medium. 
     
     
         9 . The unit of  claim 8  wherein the thermal transfer medium comprises water. 
     
     
         10 . The unit of  claim 1  wherein T T  is a melting point of the PCM, wherein charging the TES unit comprises a charging temperature in a second temperature range to store thermal energy and discharging the TES unit comprises a discharge temperature in a first temperature range to dissipate thermal energy. 
     
     
         11 . The unit of  claim 10  wherein the PCM comprises a PCM for storing thermal energy for heating applications. 
     
     
         12 . The unit of  claim 11  wherein:
 the charging temperature in the second temperature range is greater than about T T ; and   the discharging temperature in the second temperature range is less than about T T .   
     
     
         13 . The unit of  claim 10  wherein the PCM comprises a PCM for storing thermal energy for storing and sustaining heat to provide hot water. 
     
     
         14 . The unit of  claim 10  wherein the PCM comprises a PCM for storing thermal energy for cooling applications. 
     
     
         15 . A method of storing thermal energy comprising:
 providing a TES unit including an encasement containing a PCM in an internal cavity of the encasement, the encasement includes at least a fin coupled to inner surface of the encasement to separate the cavity into a plurality of sub-cavities which are at least in fluid communication, the PCM comprising a threshold temperature T T , a first temperature range corresponding to a first phase of the PCM and a second temperature range corresponding to a second phase of the PCM;   charging the TES unit with a thermal transfer medium at about a second temperature range to change the PCM from a first phase to a second phase, wherein the changing from the first phase to the second phase stores latent thermal energy; and   discharging the TES unit at about a second temperature range to change the PCM from the second phase to the first phase to release latent thermal energy to sustain a thermal transfer medium temperature at about the threshold temperature.   
     
     
         16 . The method of  claim 15  wherein the thermal transfer medium comprises water. 
     
     
         17 . The method of  claim 16  wherein a plurality of TES units are provided in the tank. 
     
     
         18 . The method of  claim 17  wherein the thermal energy stored provides thermal energy for heating. 
     
     
         19 . The method of  claim 17  wherein the thermal energy stored provides thermal energy for cooling. 
     
     
         20 . A thermal energy storage system comprising:
 a tank with an input port and output port;   at least one TES unit disposed in the tank, wherein a TES unit comprises an encasement with an internal cavity separated into sub-cavities which are in fluid communication by a fin partially coupled to an inner surface of the encasement; and   an energy source coupled to the tank.