Heat storage tank with improved thermal stratification

Abstract

Heat storage tank comprising an envelope ( 2 ) with a longitudinal axis (X) filled with a heat transfer liquid and solid heat storage elements, a first longitudinal end provided with first means ( 10 ) for collecting and supplying a liquid at a first temperature and a second longitudinal end provided with second means ( 12 ) for collecting and supplying a liquid at a second temperature, in which said solid heat storage elements are distributed across three beds (TH1, TH2 and TH3) superposed along the longitudinal axis (X), separated by a layer of liquid (L1, L2 and L3), the heat transfer liquid being capable of flowing from the first longitudinal end to the second longitudinal end.

What is claimed is: 
     
         1 - 18 . (canceled) 
     
     
         19 . Heat storage tank comprising an envelope with a longitudinal axis filled with a heat transfer liquid and solid heat storage elements, a first longitudinal end provided with a first means for collecting and supplying a liquid at a first temperature and a second longitudinal end provided with seconds means for collecting and supplying a liquid at a second temperature, in which said solid heat storage elements are distributed across at least two superposed along the longitudinal axis, separated by a layer of heat transfer liquid, the heat transfer liquid being capable of flowing between the first longitudinal end and the second longitudinal end. 
     
     
         20 . Tank according to  claim 19 , in which each bed rests on a support enabling fluid communication. 
     
     
         21 . Tank according to  claim 20 , in which at least one of the supports comprises a bearing structure and a slatted structure covered with a metal web plate. 
     
     
         22 . Tank according to  claim 20 , in which the supports are in two parts. 
     
     
         23 . Tank according to  claim 19 , in which the solid heat storage elements have at least two different particle sizes. 
     
     
         24 . Tank according to  claim 19 , in which the layer of heat transfer liquid has a thickness comprised between 1 cm and 10 cm. 
     
     
         25 . Tank according to  claim 19 , in which the envelope is a shell and in which the height of each bed is less than the diameter of the envelope. 
     
     
         26 . Tank according to  claim 19 , in which the solid heat storage elements comprise blocks of rocks and sand. 
     
     
         27 . Tank according to  claim 26 , in which the blocks of rock are formed from alluvial rocks. 
     
     
         28 . Tank according to  claim 19 , in which the heat transfer liquid is an oil. 
     
     
         29 . Tank according to  claim 19 , in which the first and/or the second collecting and supplying means comprise a distributor assuring transversal homogeneity of the axial velocity of the fluid. 
     
     
         30 . Tank according to  claim 29 , in which the envelope is a shell and the second distributor comprises a supply duct extending along the diameter of the envelope and distribution ducts extending laterally from the supply duct, said distribution ducts being provided with orifices distributed along the length thereof. 
     
     
         31 . Tank according to  claim 30 , in which the distribution ducts have different lengths such that the contour of the distributor has substantially the shape of a circle. 
     
     
         32 . Tank according to claim  1 , in which the second supplying and collecting means are isolated from the solid heat storage elements. 
     
     
         33 . Solar power plant comprising at least one heat tank according to  claim 19 . 
     
     
         34 . Solar power plant according to  claim 33 , in which the solar power plant is a Fresnel type solar power plant. 
     
     
         35 . Solar power plant according to  claim 33 , in which the solar power plant is a tower solar power plant. 
     
     
         36 . Solar power plant according to  claim 33 , in which the first and the second means for collecting and supplying the tank are connected to a turbine.