Solar derived thermal storage system and method

Abstract

The present invention is a method for storing solar collected heat and using the stored heat to produce power, comprising the steps of diverting solar heated fluid at a temperature greater than a predetermined power plant block (PPB) nominal temperature from a heat transfer circuit; transferring heat from the diverted solar heated fluid to a portion of a liquid water storage medium maintained at a temperature significantly less than the predetermined PPB nominal temperature and thermally storing the heated portion; and transferring heat from the heated liquid water storage medium to a fluid during periods of decreased solar radiation levels, whereby to produce power by means of said heated heat transfer fluid. The present invention is also directed to a solar derived thermal storage system, comprising a hot water storage medium (HWSM), a cold water storage medium (CWSM), conduit means interconnecting the HWSM and said CWSM, and a storage medium heat exchanger in heat exchanger relation with the conduit means and with solar heated fluid, for heating thermally storable water flowing from said CWSM to said HWSM when the solar radiation is above a nominal value which establishes a predetermined power plant block (PPB) nominal temperature.

1 . A method for storing solar collected heat and using the stored heat to produce power, comprising the steps of:
 a) diverting solar heated fluid at a temperature greater than a predetermined power plant block (PPB) nominal temperature from a heat transfer circuit;   b) transferring heat from said diverted solar heated fluid to a portion of a liquid water storage medium maintained at a temperature significantly less than said predetermined PPB nominal temperature and thermally storing said heated portion; and   c) transferring heat from said heated liquid water storage medium to a fluid during periods of decreased solar radiation levels, whereby to produce power by means of said heated heat transfer fluid.   
     
     
         2 . A solar derived thermal storage system, comprising a hot water storage medium (HWSM), a cold water storage medium (CWSM), conduit means interconnecting said HWSM and said CWSM, and a heat storage medium heat exchanger in heat exchanger relation with said conduit means and with solar heated fluid, for heating thermally storable water supplied from said CWSM to said HWSM when the solar radiation is above a nominal value which establishes a predetermined power plant block (PPB) nominal temperature. 
     
     
         3 . The thermal storage system according to  claim 2 , further comprising a preheater for preheating heat transfer fluid by means of said heated thermally storable water flowing from said HWSM to said CWSM when said solar radiation decreases below a nominal level. 
     
     
         4 . The thermal storage system according to  claim 2 , further comprising a preheater for preheating motive fluid of said PPB by means of said heated thermally storable water flowing from said HWSM to said CWSM when said solar radiation decreases below a nominal level. 
     
     
         5 . The thermal storage system according to  claim 3 , further comprising a further heat exchanger for boiling the preheated motive fluid of said PPB by means of said heated thermally storable water flowing from said HWSM to said CWSM when said solar radiation decreases below the nominal level. 
     
     
         6 . The thermal storage system according  3  wherein said a hot water storage medium (HWSM), a cold water storage medium (CWSM) are contained in two separate tanks. 
     
     
         7 . The thermal storage system according  3  wherein said a hot water storage medium (HWSM), a cold water storage medium (CWSM) are contained in one tank separated by a thermocline.