Heat store

Abstract

Known high-temperature heat storage devices for the storage of heat at a temperature above 100° C. having a container for heat-storing bulk material such as gravel/ceramic spheres have a steel wall which is constructively extremely complex to manufacture for larger heat storage devices or the storage of heat at higher temperatures. According to the invention, the side wall of the heat storage device for its part is supported by a supporting bulk material and is preferably inclined, with the result that the side wall is substantially less stressed and can be made of a non-metal material such as, for example, concrete. Such a heat storage device is simple and inexpensive to manufacture and allows long-term storage of larger amounts of heat at high temperatures.

1 . A heat storage device comprising:
 a container for heat-storing material, which comprises a side wall enclosing said material; and   wherein the heat-storing material comprises a dry filling of bulk material having a temperature exceeding 100° C. during the heat storage and that the side wall for receiving the operating pressure of the heat-storing bulk material is for its part supported towards the outside on a supporting bulk material.   
     
     
         2 . The heat storage device according to  claim 1 , wherein the supporting bulk material is compacted compared with the looser filling state. 
     
     
         3 . The heat storage device according to  claim 1 , wherein at least segments of the side wall are inclined at an angle of inclination with respect to the horizontal in such a manner that the container expands towards the top. 
     
     
         4 . The heat storage device according to  claim 3 , wherein the angle of inclination is between 50 and 85 degrees, preferably between 60 and 80 degrees, particularly preferably 70 degrees. 
     
     
         5 . The heat storage device according to  claim 3 , wherein:
 the heat-storing bulk material has a passive pressure during operation which is higher than the operating compressive strength of the side wall; and   its angle of inclination with respect to the horizontal has a value in such a manner that the operating pressure of the heat-storing bulk material is lower than the operating compressive strength of the side wall.   
     
     
         6 . The heat storage device according to  claim 1 , wherein the heat storage device is sunk in the ground and the material of the ground at least partially forms the supporting bulk material or that a bulk material is used that is different from the material of the ground. 
     
     
         7 . The heat storage device according to  claim 1 , wherein the heat storage device is partially sunk in the ground and the ground itself at least partially forms the supporting bulk material for the sunken area of the side wall and wherein the region of the side wall projecting above the ground is supported by a heaped supporting bulk material. 
     
     
         8 . The heat storage device according to  claim 1 , wherein the heat storage device is disposed on or above the ground and the supporting bulk material is heaped around the side wall. 
     
     
         9 . The heat storage device according to  claim 1 , wherein the supporting bulk material is surrounded by an outer end wall. 
     
     
         10 . The heat storage device according to  claim 1 , wherein the side wall comprises a non-metallic material and preferably has metal reinforcing elements. 
     
     
         11 . The heat storage device according to  claim 10 , wherein the side wall comprises preferably pre-fabricated segments, which intermesh at the edge. 
     
     
         12 . The heat storage device according to  claim 10 , wherein the side wall comprises concrete. 
     
     
         13 . The heat storage device according to  claim 12 , wherein the side wall comprises compacted light concrete or aerocrete. 
     
     
         14 . A concrete segment for the side wall of a heat storage device according to  claim 1 , wherein the concrete segment is formed as an elongate flat panel, whose two straight longitudinal edges are configured as a step, which can be brought into engagement with the step of a neighbouring concrete segment, wherein the width of the concrete segment at the lower end is smaller than that at the upper end and the lower width, the upper width and the ratio of the widths is pre-determined in such a manner that a number of concrete segments with engaged longitudinal edges can be joined together to form a closed jacket of a truncated cone. 
     
     
         15 . The concrete segment according to  claim 14 , wherein a body of the concrete segment is curved over its length in the direction of the width, wherein the radius of curvature becomes smaller from the broader end towards the narrower end and is configured in such a manner that it substantially corresponds to the radius of curvature of the truncated cone. 
     
     
         16 . The concrete segment according to  claim 14 , wherein the angle of inclination of the jacket of the truncated cone with respect to the horizontal is between 50 to 85 degrees, preferably between 60 to 80 degrees, particularly preferably 70 degrees. 
     
     
         17 . The concrete segment according to  claim 14 , wherein the side wall comprises concrete, preferably light concrete or aerocrete. 
     
     
         18 . The concrete segment according to  claim 17 , wherein the concrete is compacted. 
     
     
         19 . A heat storage device comprising:
 a container for heat-storing material which comprises a side wall enclosing said material; and   wherein the heat-storing material comprises a dry filling of bulk material, having a temperature exceeding 100° C. during the heat storage and that at least segments of the side wall are inclined at an angle of inclination with respect to the horizontal in such a manner that the container expands towards the top.   
     
     
         20 . The heat storage device according to  claim 1 , wherein the angle of inclination is between 50 to 85 degrees, preferably between 60 to 80 degrees, particularly preferably 70 degrees. 
     
     
         21 . The heat storage device according to  claim 19 , wherein:
 the heat-storing bulk material has a passive pressure during operation which is higher than the operating compressive strength of the side wall; and wherein   its angle of inclination with respect to the horizontal has a value in such a manner that the operating pressure of the heat-storing bulk material is lower than the operating compressive strength of the side wall.   
     
     
         22 . The heat storage device according to  claim 19 , wherein the side wall comprises a non-metal material and preferably has metal reinforcing elements. 
     
     
         23 . The heat storage device according to  claim 8 , wherein the side wall comprises preferably pre-fabricated segments, which intermesh at the edges, wherein the segments particularly preferable comprise concrete. 
     
     
         24 . The heat storage device according to  claim 1 , wherein a temperature of the heat-storing bulk material reaches or exceeds at least 100° C., preferably at least 200° C., particularly preferably at least 400° C., even more preferably 500° C. 
     
     
         25 . The heat storage device according to  claim 1 , wherein:
 the temperature distribution in the heat-storing bulk material is stratified during the storage of heat; and   an uppermost layer of the bulk material has the highest temperature and a lowermost layer of the bulk material has the lowest temperature.   
     
     
         26 . The heat storage device according to  claim 25 , wherein the highest temperature reaches or exceeds 500° C. and the lowest temperature lies below 100° C. 
     
     
         27 . A method for operating a heat storage device according to  claim 1  having a heat-storing dry filling of bulk material, which is surrounded by a side wall enclosing said material, wherein the bulk material has a temperature exceeding 100° C. during the heat storage and the side wall is for its part supported against the outside on a supporting bulk material to absorb the operating pressure of the heat-storing bulk material, wherein the bulk material for storage of heat is perfused by a hot fluid from top to bottom, whose inlet temperature lies below 100° C., in such a manner that the bulk material in an upper zone of the heat storage device is heated to substantially the inlet temperature, in a middle zone lies between substantially the inlet temperature and 100° C. and in a lower zone lies below 100° C. and that the further supply of heat is determined in such a manner that the temperature in the lower zone during the storage duration is always below 100° C. 
     
     
         28 . The method according to  claim 27 , wherein the temperature in the upper zone reaches or exceeds at least 200° C., particularly preferably at least 400° C., even more preferably 500° C.