Long-Term Heat Storage Device and Method for Long-Term Heat Storage of Solar Energy and Other Types of Energy with Changing Availability

Abstract

The invention relates to a long-term heat storage device for long-term storage of solar energy and other types of energy, in the heat storage material of which a rock bulk material, in particular of volcanic origin, such as diabase, basalt, granite and gneiss, is used. The rock bulk material forms a polydisperse bulk material, in particular as the void volume of the rock bulk material (granulate) having a first particle size or particle size distribution takes up a granulate having a second particle size or particle size distribution. The rock bulk material can be enclosed by a bulk powder fill, in particular an ash fill, in particular with a shell of shaped rocks interposed. The rock bulk material can be enclosed, all around or predominantly, at least laterally, by a shell of shaped rocks which is in particular cylindrical, in particular by a masonry wall.

1 . Long-term heat storage device for the long-term storage of solar energy and other types of energy comprising a heat storage mass, characterized by a thermally insulated solid bed of a rock bulk material serving as heat storage mass, comprising a material suitable for high operating temperatures, in particular for temperatures between 100° C. and 1000° C., and having a high specific heat capacity greater than 600 J/kgK, a high thermal conductivity higher than 1 W/mK and a high density greater than 2 kg/dm 3 , the rock bul material being of volcanic origin such as diabase, basalt, granite and/or gneiss. 
     
     
         2 . The long-term heat storage device according to  claim 1 , characterized by a thermally insulated solid bed of a rock bulk material serving as heat storage mass, the rock bulk material forms a polydisperse bulk material whereby the void volume of the rock bulk material (granular material) having a first grain size or grain size distribution takes up a granular material having a second grain size or grain size distribution. 
     
     
         3 . The long-term heat storage device according to  claim 1 , characterized by a thermally insulated solid bed of a rock bulk material serving as heat storage mass, the rock bulk material together with an air supply and air removal is partially or fully surrounded with an interposed shell of shaped stones, by a bulk powder fill such as an ash fill. 
     
     
         4 . The long-term heat storage device according to  claim 1 , characterized by a thermally insulated solid bed of a rock bulk material serving as heat storage mass, the rock bulk material together with an air supply and air removal is partially or fully surrounded by an in particular cylindrical shell of shaped stones such as by a masonry wall. 
     
     
         5 . The long-term heat storage device according to  claim 1 , characterized in that the rock bulk material lays directly or indirectly on a bulk material comprising in particular micronized powder of a solid having a porous or fibrous structure, in particular of a group comprising micronized ash, powder having a large interior porous structure, sand having a porous structure, ground clay, ground brick, ground reacted solids such as activated charcoal or ground rock having a porous (spongy) structure as well as various organic substances having a fibrous structure. 
     
     
         6 . The long-term heat storage device according to  claim 1 , characterized in that one or more layers of stone such as bricks, is/are disposed on the bulk material. 
     
     
         7 . The long-term heat storage device according to  claim 1 , characterized in that a fine-grained bulk material is disposed underneath the rock bulk material and which has the same origin as the rock bulk material. 
     
     
         8 . The long-term heat storage device according to  claim 1 , characterized in that the rock bulk material such as a masonry wall surrounding the rock bulk material is surrounded by a bulk powder fill such as micronized ash. 
     
     
         9 . The long-term heat storage device according to  claim 1 , characterized in that incoming air distribution channels are disposed below the rock bulk material such as on a fine-grained bulk material. 
     
     
         10 . The long-term heat storage device according to  claim 9 , characterized in that a main air channel and air distribution channels are shaped so that outlet openings for hot air are provided at the air distribution channels so that the air is distributed uniformly over the entire base of the rock bulk material. 
     
     
         11 . The long-term heat storage device according to  claim 1 , characterized in that at the upper end of the rock bulk material exhaust air channels are laid so that the outflowing air is collected over the entire cross-section of the rock bulk material in the channels and is removed outwards. 
     
     
         12 . The long-term heat storage device according to  claim 10 , characterized in that the intermediate spaces of the air supply channels and/or the air collecting channels are filled with rock bulk material. 
     
     
         13 . The long-term heat storage device according to  claim 11 , characterized in that the space above the air collecting channels is filled with fine-grained bulk material. 
     
     
         14 . The long-term heat storage device according to  claim 13 , characterized in that the fine-grained bulk material is constructed in two layers by means of the brick. 
     
     
         15 . The long-term heat storage device according to  claim 14 , characterized in that a bulk powder fill is provided as insulation over the rock bulk material such as over the stones. 
     
     
         16 . The long-term heat storage device according to  claim 15 , characterized in that the bulk material has the same thickness as the bulk material which is disposed laterally around the brick masonry wall. 
     
     
         17 . The long-term heat storage device according to  claim 9 , characterized in that an insulated air supply pipeline inserted in a protective pipe is provided for the air inlet into the air supply distribution channels and/or for the air outlet from the exhaust air distribution channels which pipeline is provided with a cladding. 
     
     
         18 . The long-term heat storage device according to  claim 1 , characterized in that a cladding made of sheet metal shells is provided around the insulating ash layer surrounding the rock bulk material. 
     
     
         19 . The long-term heat storage device according to  claim 18 , characterized in that a covering of the rock bulk material of the masonry wall, the stones and the insulating ash layer is provided by means of the cover in such a manner that the cover is connected to the outer cladding in a watertight manner. 
     
     
         20 . The long-term heat storage device according to  claim 19 , characterized in that filling openings are provided on the cover, in order to fill the space between the outer cladding and the masonry wall with bulk powder fill. 
     
     
         21 . The long-term heat storage device according to  claim 20 , characterized in that the entire masonry wall and the rock bulk material lies on a bulk powder fill. 
     
     
         22 . The long-term heat storage device according to  claim 11 , characterized in that the thickness of the bulk powder fill is selected according to the storage capacity and according to the geometry. 
     
     
         23 . The long-term heat storage device according to  claim 1 , characterized in that the long-term heat storage device has the shape of a cylinder in which the diameter and the height of the heat storage mass are equal (D=H) and after insulation of the heat storage mass with bulk powder fill the diameter and the height of the cylinder are approximately the same (D=H). 
     
     
         24 . The long-term heat storage device according to  claim 1 , characterized in that the heat storage device lies on a plate to prevent ingress of moisture into the insulation or into the heat storage mass. 
     
     
         25 . The long-term heat storage device according to  claim 1 , characterized in that the heat storage device is laid underground so that the heat storage device is enclosed in a sleeve which is watertight in order to prevent the penetration of moisture into the insulation or into the heat storage mass. 
     
     
         26 . The long-term heat storage device according to  claim 1 , characterized in that the rock bulk material has a bulk density of at least 1600 kg/m 3 . 
     
     
         27 . Method for the long-term heat storage of solar energy and other types of energy with changing availability by means of a long-term heat storage device in which the solar energy or the other type of energy with changing availability is initially transferred to a heat transfer medium and then the thermal energy is transported into the long-term heat storage device and to the heat storage mass, characterized in that a granular material (rock bulk material) has a high specific heat capacity, high thermal conductivity and/or high density, and has a volcanic origin such as basalt rock, diabase rock, granite rock and/or gneiss rock, and is provided in a solid bed as heat storage mass, that the granular material is insulated in a suitable manner so that the heat losses remain low during a long period of time, wherein the heat insulating material has a plurality of contact resistances and/or its thermal conductivity is low and/or its structure is spongy, fibrous or porous and comprises a micronized powder such as micronized ash and that the granular material is heated to a high temperature by means of a heat transfer medium interacting with the granular material by means of air.