DE102009033413A1 - Improvement of the heat transfer and the heat capacity of heat accumulators - Google Patents

Abstract

The present invention relates to the use of superabsorbent materials to increase the heat capacity or to improve the heat transfer in heat stores. The present invention also relates to a heat store comprising at least one superabsorbent material, in particular a geothermal heat store.

Description

Technical area

The The present invention relates to the use of superabsorbent Materials to increase the heat capacity or to improve the heat transfer in heat storage. The present invention further relates to heat storage comprising at least one superabsorbent material, in particular Geothermal memory.

Background of the invention

One general problem of conventional heat supply is that the existing heat at its source or time of origin is often not directly usable, because the energy supply fluctuates daily and seasonally and the Energy demand often occurs this time-delayed. at The use of solar energy, for example, becomes energy during the day or amplified during the summer months while generated the main consumption times occur at night or during the winter months. Both to compensate for such daytime fluctuations, as Heat storage technologies are also used to compensate for seasonal fluctuations used. For heat storage over short as well as long periods are often underground geothermal energy storage used.

In Thermal storage tanks or geothermal energy can heat energy stored in soil or rock masses underground. there For example, geothermal energy stores serve the purpose of balancing seasonally Conditional temperature fluctuations or daily temperature fluctuations in one the natural heat, mostly solar heat, using heating system. In the effort, the heating of decoupling buildings from fossil fuels increasingly coupled systems such as solar energy, combined heat and power, or geothermal energy gained in importance. The heat storage effectively serves as a buffer to offset the timing of Heat accumulation and heat requirement (day-night / summer-winter) compensate. Taking advantage of the heat capacity of the ground, for example below buildings, to Storage of heat, for example, it is possible Heat generated in the summer from solar energy using solar systems to cover the heating and / or domestic hot water needs of Store living and working spaces and thus at night or to make usable in winter, in which by solar energy amount of heat is low. Also the storage of power plant heat or geothermal energy in geothermal energy storage has already been suggested.

The technical solutions commonly used for heat storage include on the one hand tanks with water filling, for example, installed in the basement of a building or in the adjacent soil and connected by heat exchangers or heat pumps with the heating system or hot water system of the house, see, for. B. DE 20101963 U1 , In these stores, the high specific heat capacity of the water is used, but this liquid-tight and heat-insulating demarcated water tanks in the or outside of the building with considerable space and maintenance required for the surrounding soil.

Furthermore, geothermal storage are known which store via probes, pipes, boreholes or similar devices supplied heat underground in the ground. For this purpose, depending on geological conditions, for example, naturally present rock strata can be used as a storage medium, or specially for the heat storage underground geothermal storage. These may be isolated from the environment (hermetic storage) or at least partially openly connected to the environment (non-hermetic or semi-hermetic storage). The heat supply and heat dissipation into the storage media is usually via probes or pipes, which are usually connected via a heat exchanger with a heating system. The probes or pipelines can be introduced via bores in the storage medium, or are embedded in a bulk storage medium in this, see, for. B. EP 0056797 A2 . DE-OS-2731178 ,

In the latter geothermal energy storage probes or pipes are often surrounded with concrete mixtures or hardening cementitious rock mixtures to firmly enclose the heat-conducting geothermal probes for the purpose of better heat transfer to the surrounding rock, see, for. B. DE 3101537 A1 . DE 10 2005 037 587 U1 , A disadvantage of such installations is that in the case of leaks in the probe system or the pipes, these are no longer easily accessible from the outside, thus making maintenance difficult. Another disadvantage of such systems is that the heat transfer from the heat supplying probes or pipes into the surrounding rock is suboptimal.

Since water has a higher specific heat capacity than sand, gravel or rock, geothermal storage tanks are often saturated with water or kept moist. In general, this also raises the problem that due to the constant supply of heat energy, a progressive dehydration of the storage masses takes place. This dehydration, especially in near-surface layers, on the one hand lead to considerable heat losses through evaporation or diffusion, on the other hand to a reduction of the specific heat capacity of the storage medium as a whole. In addition, due to drying out of the material directly on the tubes or probes, the heat transfer to or from the surrounding medium worsens. The same applies to probes for geothermal heat recovery systems.

It There is therefore a need for improved heat storage with increased heat capacity. It also exists a need for technical solutions to improve the Heat transfer in heat accumulators, in particular Underground geothermal energy storage, and / or geothermal Probe systems.

task The invention is therefore, possibilities for improvement or increase the heat capacity and / or the heat transfer in heat storage, especially in underground geothermal energy stores, and / or specify geothermal probe systems. In addition, it is an object of the invention, heat storage, in particular specify underground geothermal storage, which improved Heat capacity and / or improved heat transfer exhibit.

The The above objects and other objects are achieved according to the invention by the subject matter of the independent use and product claims. Preferred embodiments are dependent Claims specified.

Summary of the invention

According to one Aspect, the present invention relates to the use of a superabsorbent Material for increasing the heat capacity in heat storage. According to another Aspect, the present invention relates to the use of a superabsorbent Material for improving the heat transfer from heat exchangers to these surrounding ones solid storage material, in particular on the solid memory core in heat storage.

According to one Another aspect of the present invention is a heat storage comprising at least one superabsorbent material provided.

Description of the figures

1 shows the schematic structure of a geothermal reservoir according to the invention.

2 shows an alternative exemplary arrangement of embedded in superabsorbent material ground probe in a subterranean geothermal storage.

3 shows a diagram of different specific heat capacities of different heat storage materials.

Detailed description of the invention

at Try to determine the water retention capacity of superabsorbent Materials in sandy soils have been shown to be so when using such Materials an increase in field capacity (the one Amount of water that is an initially water-saturated Can still hold ground against gravity after 3 to 4 days) occurs. The increase in field capacity surprisingly results also a significant improvement in specific heat capacity of the soil mixed with superabsorbent material. There water a higher specific heat capacity as sand, rock or soil particles, causes the water retention into the superabsorbent materials mixed with the rock a significant increase in heat capacity the mixture of superabsorbent materials and sand. By the water retention forces of the introduced into the soil Superabsorbent materials will cause evaporation of the Water even with heat input over a longer Period largely prevented or significantly reduced.

Consequently can be stored in heat stores containing superabsorbent materials Heat losses are prevented by evaporation. By the mechanism of incorporation of the water in the polymer and its binding In the polymer as well as an undesirable energy diffusion in open, non-hermetic heat storage systems by vertical or horizontal water transport suppressed because the existing Water is fixed in the superabsorbent polymer. Further, it has become shown that water-absorbed superabsorbent materials For example, passing rainwater or groundwater Keep away from the storage material and thus continue heat losses reduce heat transfer from the heat storage or prevent. Moreover, the use prevents it water-retaining, superabsorbent materials in hermetically sealed Heat storage in case of leakage leakage of water, whereby here too heat losses are reduced or avoided, but at least delayed.

In contrast to inorganic water-storing materials such as clay, the elastic behavior of the superabsorbent polymeric materials has an additional effect cheap. Due to the volumetric expansion of the polymeric materials in the case of water absorption, a swelling pressure is built up in the trays or storage media, which leads to a considerably better heat transfer and an improved distribution of the heat introduced into or removed from the heat transfer medium by the heat transfer medium.

According to the The present invention is used to increase the specific Heat capacity and / or the improvement of heat transfer in heat accumulators at least one superabsorbent material used. Superabsorbent materials according to the invention are such substances that are insoluble in water and a Record multiple of their own weight in water and at least temporarily can bind.

The term "superabsorbent material" as used herein includes two types of fabrics as described herein. On the one hand, these are organic superabsorbent polymers, which are also referred to as superabsorbents, hydrogels or as Superslurper and from applications in the field of hygiene such. B. in diapers and sanitary napkins are known. In alternative embodiments, the term "superabsorbent material" is a hybrid material of superabsorbent organic polymer having copolymerized therein or integrated mineral components, such as commercially available under the Description of product Geohumus ^®. Both types of material can be used according to the invention as superabsorbent material.

There Water has a higher specific heat capacity when, for example, has rock, it becomes water when used absorbent superabsorbent materials in heat accumulators the total heat capacity related to the mass used of the used storage material (specific heat capacity) significantly increased. The terms specific heat capacity and heat capacity are used synonymously herein and refer to the mass of the given in the context Material or material mixture. The extent of possible Increase in the specific heat capacity is on the one hand by the amount of superabsorbent used Material in relation to the other heat-storing Material, as well as the water content of the used superabsorbent Material dependent.

The according to one aspect of the present invention provided or usable with the invention heat storage can use any type of conventional heat storage be, that is aboveground or underground heat storage, preferably underground geothermal storage. The heat storage can be hermetic, that is closed Be systems in which the heat or cold storing medium or the heat-storing material by an enclosure or insulation of the environment in essence is completed. Furthermore, the heat storage according to the present invention also non-hermetic heat storage be, that is such heat storage, in which the heat-storing material, for example soil, Sand, gravel, earth or rock, not or only partially from the Environment is shielded or completed.

Non-hermetic Heat storage are, for example, underground geothermal storage, in which the heat exchanger such. B. geothermal probes or heat exchanger tubes for the supply and discharge stored heat underground in the ground or through holes are introduced into solid rock. The heat exchangers can z. B. are introduced into excavations and then with bulk material such as soil, excavation, gravel, sand, rocks and mixtures thereof are filled. Such geothermal storage are known in the art and are everywhere in the simplest case applicable where the risk of heat loss through inflow or outflow of groundwater or leachate or not is not given to a relevant extent.

at Hermetic heat storage usually becomes an enclosure, shell or shuttering of the storage media with the heat exchangers embedded in it provided, with heat losses to the environment through a suitable insulation and / or sealing is prevented.

Of course Heat storage are basically not only for Heat storage, but also for storing cold, suitable for air conditioning purposes. The present Invention can be used both in the field of heat storage, as well as the cold storage can be used. This here used term of heat storage includes therefore always the storage of cold with a.

According to the The present invention is achieved by using superabsorbent Material in such conventional heat storage, in particular Geothermal heat storage improves the heat transfer and / or the specific heat capacity of the heat increasing material or material mixture increases.

According to one embodiment, superabsorbent materials which can be used according to the invention comprise at least one superabsorbent organic polymer. Preferably, the superabsorbent organic polymer is a polymer or copolymer of polyacrylic acid, polymethacrylic acid, Copolymers of acrylic acids and salts of acrylic acid (especially acrylic acid sodium salt or acrylic acid potassium salt), polysaccharides, polyacrylamides, or mixtures thereof, and / or generally hydrogels, polyvinylpyrrolidone and like organic polymers which may optionally be crosslinked. These polymeric materials, although insoluble in water, can hold water in an amount that is a multiple of the dry polymer's own weight.

According to the invention preferred are superabsorbent materials that are at least 10 times at least 25 times, at least 50 times and more preferably at least 80 times its dry weight of water in free swelling at room temperature, eg. B. 20 ° C, can accommodate.

Especially preferred superabsorbent organic polymers are crosslinked Copolymers of acrylic acid and acrylic acid sodium salt and / or acrylic acid and acrylic acid potassium salt.

According to a particularly preferred embodiment of the present invention, the superabsorbent material used is a hybrid material of superabsorbent organic polymer (e.g., as described above) having incorporated therein mineral constituents. Such hybrid materials and their preparation is described, for example, in the international patent applications WO 2006/119828 and WO 2003/000621 whose content is hereby incorporated by citation. Hybrid materials of this type are available under the name Geohumus ^® from Geohumus International GmbH, Frankfurt / Main, Germany, in trade,

These Hybrid materials are made of superabsorbent organic polymers as mentioned above, preferably from crosslinked copolymers of Acrylic acid and acrylic acid sodium salt and / or acrylic acid potassium salt, where there are mineral components such as minerals, sand and the like during the polymerization reaction in the resulting polymer Network polymerized and thus in the resulting spongy, crosslinked organic polymer matrix are involved. These hybrid materials like superabsorbents, although insoluble even in water, To absorb water in an amount that is a multiple of its own weight of the dry hybrid material.

In particular embodiments may be further Increase in the specific heat capacity these hybrid materials may use modified hybrid materials containing, for example, metal powders such as iron powder or are offset with these. Such materials are according to the described in the above international patent applications accessible in principle, with only the mineral content at least partially replaced by metal powder.

The Hybrid materials mentioned herein can be used in the present Invention as the pure superabsorbent itself advantageous for improvement the heat transfer in heat storage and to improve or increase the specific heat capacity be used in heat storage.

The superabsorbent material becomes the invention Use with conventional usable in heat storage Materials such as a bulk material mixed and then the mixture in the heat storage as heat storing material used. Alternatively, the mixture of the superabsorbent material with the bulk material with further heat-storing material blended or this added. In the case of superabsorbent polymers causes the Mixing of the superabsorbent polymer with suitable bulk material Among other things, that swelling of the swelling polymers at strong access of water is avoided and the superabsorbent Store polymer as evenly as possible in the heat Medium is distributed.

in the Case of using hybrid materials becomes flooding or a separation of the material mixture by the sponge-like structure of the hybrid material, which has a toothing in the bulk material causes avoided.

in the Generally, the superabsorbent material is as much as possible evenly distributed in the heat storage.

at hermetically sealed underground geothermal energy storage it may be preferable to use the mixture of superabsorbent material adjacent to bulk materials in close proximity the geothermal probes or heat exchanger piping to introduce or to introduce there in higher concentration, such that this material mixture contains superabsorbent material a connection of the probes or pipes with the surrounding Storage medium, for example, rocks, manufactures.

Due to the increase in the specific heat capacity on the one hand and the increase in the thermal conductivity caused by the water absorption and water-holding capabilities of the superabsorbent material, this embodiment significantly improves the heat transfer from the heat probes or heat exchanger tubes to the surrounding rock, since the mixture containing the superabsorbent material due to its higher specific heat capacity, it can absorb the introduced heat better and distribute it through the improved thermal conductivity in the surrounding storage material. The heat transfer in heat accumulators and their coupling to surrounding earth areas is hereby considerably improved.

About that In addition, the elastic property of the provides in the presence of water swelling superabsorbent material for improved contact the storage medium with the probes or heat exchanger tubes, so that even with strongly fluctuating temperatures a heat conductive contact between the storage medium and the probes or Piping can be guaranteed and the formation heat insulating gaps or air layers is largely avoided.

The bulk material usable for mixing with the superabsorbent material can be any material used in conventional heat storage be, for example, soil, sand, gravel, soil, clay, overburden, slag, Building rubble, excavated material and the like, and mixtures thereof. The mixture of the superabsorbent material with the bulk material can be done before the mixture in the heat storage is introduced. Alternatively, the superabsorbent material be introduced into already existing heat storage, for example via holes, by lifting, compressed air injection or similar measures.

There the superabsorbent hybrid materials already have mineral components to a considerable extent, preferably more than 30 weight percent or even more than 50 wt .-% based on the total weight of the dry Hybrid material, is one for their use in heat accumulators Bulk mixing in some embodiments not absolutely necessary, the hybrid material can be used as sole Storage material can be used.

Preferably However, the hybrid material, as well as the superabsorbent Polymer, for the use according to the invention in heat accumulators with suitable bulk material used mixed as described above.

One another advantage of the above hybrid materials pure superabsorbers is that they no longer hydrogels themselves form, but a sponge-like structure, by their mineral content is adequately weighted and conflicted with your structure Bulk material is usually toothed to even with strong water access in the heat storage no suspension or draining the hybrid material.

According to this Embodiment of the present invention may be the hybrid material evenly distributed in the ground storage or preferably in close proximity or in the immediate vicinity of Heat probes or the heat exchanger piping be introduced to a heat conductive connection between to ensure the probes or pipes and the surrounding storage medium. In certain embodiments, the hybrid material with bulk materials such as soil, sand, gravel and the like be mixed or incorporated into it.

Preferably The superabsorbent material is mixed in the dry state with bulk material and / or introduced into the heat accumulator and then with water in a suitable amount, preferably to saturation, brought to swelling. This is especially true for hermetic systems prefers. In non-hermetic heat storage can suitable delivery systems to keep the superabsorbent moist Be provided material, for example by feeding of rainwater and / or groundwater in open geothermal reservoirs.

In In all embodiments of the invention, the storage medium the heat accumulator wholly or partly from superabsorbent Material exist. Also mixtures of hybrid material with conventional Superabsorbents can be used as superabsorbent material be used.

Preferably is used in geothermal energy storage to increase the specific Heat capacity and / or improvement of heat transfer the at least one superabsorbent material in sufficient Quantity used to the specific heat capacity of the mixture in the wet state against the dry Heat-storing material without superabsorbent material at least 1.5 times, preferably at least twice, particularly preferably at least three times increase. The superabsorbent material is added in amounts of 0.5% by weight to 100% by weight in the heat-storing material as herein described, based on the dry total mass, preferably more 1% by weight, about 2 to 50% by weight, 2.5 to 25% by weight, 3 to 20% by weight, and more preferably about 2 to 10% by weight.

In the case of using pure superabsorbent organic polymers, the proportion of the superabsorbent polymer in the bulk material or heat-storing medium is at least about 0.5 wt%, at least about 1 wt%, preferably 2 wt% to 100 Weight percent, preferably 2 to 30 wt .-%, 2.5 to 25 wt .-%, 3 to 25 wt .-%, and particularly preferably from about 2 to 10 wt .-% but usually not more than 25 weight percent. The percentages by weight always refer to dry, that is substantially anhydrous superabsorbent material, based on the total weight of the mixture or the total weight of the storage medium in the heat exchanger.

at Use of superabsorbent hybrid materials in the mixture with bulk material is the amount of hybrid material in the mixture at least about 1% by weight, for example from 2 to 100 Weight percent, preferably 2 to 50 wt .-%, 2.5 to 25 wt .-%, 3 to 20% by weight, and more preferably about 2 to 10% by weight, optionally also 20 to 50 weight percent of the mixture, based on dry material

In other embodiments, the superabsorbent Materials in the immediate vicinity of the heat exchanger as heat exchanger tubes or heat probes be used in stores that use fixed storage media, such as rock or concrete, in which the probes or heat exchangers are drilled with holes or be embedded in concrete. This will be constructive cavities around the probe body with superabsorbent materials and their mixtures filled and with a device or opening for irrigation.

Prefers However, geothermal storage, in which as storage materials Bulk materials are used, which is a subsequent Removal of the heat probes or pipes, for example for maintenance purposes.

The particular advantages of the present invention are that by using superabsorbent materials, whether in admixture with Bulk material or by using mineral rock Hybrid materials as described above, the heat transfer of heat probes or heat exchanger pipelines can be significantly improved in heat storage. The superabsorbent organic polymers or hybrid materials have a significantly increased specific by intake of water Heat capacity compared to rock materials. This also results in mixtures of the superabsorbent polymers or the hybrid materials with bulk material by water absorption and binding of the water in the polymer portion as a whole a significant Increase in the specific heat capacity of the heat storage material used in the geothermal storage. At the same time, due to the hydrogel properties or spongy structure of the superabsorbent materials used a sufficient flexibility, even in case of temperature fluctuations caused movements within the storage medium or probes like stretching, compression, the formation of cavities, Air bubbles and the like, the heat pipe insulators represent that a constant heat transfer continuously ensured at high heat capacity can be.

The superabsorbent materials also have a high water retention power, as they also drain water Absorb the surrounding storage medium and retain it sustainably can, so that by high heat input at heat accumulators prevented by the prior art dehydration phenomena or largely avoided or delayed in the longer term can be. Here are these materials in particular superior to inorganic water absorbers such as bentonite, clay and the like.

The Use of superabsorbent materials in heat accumulators, especially in geothermal storage, z. B. in connection with heat exchanger systems, heating systems, service water systems and systems for using renewable energy, such as Solar systems and the like, therefore, provides a cost-effective and highly effective measure to improve the energy balance Such heat storage systems, as they heat losses due to low heat capacity and in particular avoid poor or fluctuating heat transfer helps.

The Invention is further illustrated by the attached figures, show the individual embodiments of the invention, however are not meant to be limiting.

Referring to the 1 a schematic structure of a heat accumulator according to the invention is shown. In the embodiment of the 1 is a geothermal heat storage, in which a heat exchanger, such as a geothermal probe 1 , in a superabsorbent material containing 2 is embedded. The heat exchanger or the ground probe 1 can z. As a coiled tubing, a tube bundle, a plate exchanger, etc., which are commonly used in conventional energy storage technology as a heat exchanger. These heat exchangers or probes of conventional design are made of a suitable material, such as metals or plastic, which is a heat transfer from the probe to the heat-storing environment 3 allows. The solid, heat-storing environment 3 is, for example, soil, rock, concrete, or artificially constructed piles of gravel, sand, etc. In the case of hermetic heat storage, the heat-storing environment in a housing, for example in the form of isolie enclosed walls to reduce heat loss. Underground geothermal energy storage are geothermal probes 1 , Superabsorbent material 2 and heat-storing environment 3 as in 1 shown below the surface of the earth 4 arranged, z. B. below a building, garden or driveway. As in 1 shown is the ground probe 1 in a conventional manner, if necessary via a circulation pump 5 directly or via a heat exchanger 6 connected to a heat source and / or a heating or cooling system. This is in liquid heat transfer agents in the geothermal probe with the return 7 closed a cycle.

2 shows an alternative exemplary arrangement of the ground probe 1 , embedded in superabsorbent material 2 in an underground geothermal energy storage.

1

= trockener Sand

2

= nasser Sand, ca. 21 Gew.-% Wassergehalt

3

= Wasser

4

= wassergequollenes Hybridmaterial (1 Teil Geohumus^® mit 10 Teilen Wasser) in einer Menge von 50 Gew.-% in Sand (entsprechend ca. 4,5 Gew.-% trockenem Geohumus^®-Anteil im Gemisch)

5

= wassergequollenes Hybridmaterial (1 Teil Geohumus^® mit 10 Teilen Wasser)

6

= wassergequollenes Hybridmaterial (1 Teil Geohumus^® mit 50 Teilen Wasser)

7

= wassergequollener Superabsorber (1 Teil SAP mit 5 Teilen Wasser)

8

= wassergequollener Superabsorber (Hydrogel) (1 Teil SAP mit 100 Teilen Wasser)

3 shows the different specific heat capacity of selected materials and material mixtures usable according to the invention compared to water, dry and moist sand. The individual bars and numerical values represent the measured heat capacity of the following materials and material mixtures:

1

= dry sand

2

= wet sand, about 21 wt .-% water content

3

= Water

4

= Water-swollen hybrid material (1 part Geohumus ^® with 10 parts of water) in an amount of 50 wt .-% in sand (corresponding to about 4.5 wt .-% of dry content in the mixture Geohumus ^®)

5

= Water-swollen hybrid material (1 part Geohumus ^® with 10 parts of water)

6

= Water-swollen hybrid material (1 part Geohumus ^® with 50 parts of water)

7

= water-swollen superabsorber (1 part SAP with 5 parts water)

8th

= water-swollen superabsorbent (hydrogel) (1 part SAP with 100 parts water)

The used water was desalted, the sand came from the quartz works Baums, type L60, the superabsorber used was from Evonik, Stockosorb type. The specific heat capacity was measured by calorimetric measurement; Values given for 20 ° C.

3 shows clearly that even slightly swollen with water hybrid material in mixture with sand leads to a significant increase in the specific heat capacity of the mixture. By adding a water-saturated material with superabsorbent properties, a significant increase in the heat capacity of soils (here sand) can be achieved. The heat capacity of the mixture of sand with partially swollen hybrid material surpasses that of wet sand, the hybrid material mixture having the advantage that the water is bound in the polymer and thus is no longer freely mobile. Heat losses through diffusion and evaporation are avoided. It is also to be expected that the heat capacity of this mixture will increase even more when water is taken up.

Furthermore, you can in 3 recognize that the achievable specific heat capacity values of the hydrous superabsorbent materials are above those of pure water (4.2 J / (g · K)). This is, without wishing to be bound by any particular theory, to explain that the water molecules are embedded in the polymer matrix and thus are no longer freely movable. This prevents unimpeded heat transfer or 'flow' through non-localized water molecules.

Exactly This is the geothermal systems and geothermal energy storage desirable because of a relatively stationary bond of water molecules around the heat exchanger probe around a 'virtual tank' of increased heat capacity opposite the 'normal ground' arises.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20101963 U1 [0004]
• - EP 0056797 A2 [0005]
• - DE 2731178 A [0005]
• DE 3101537 A1 [0006]
• - DE 102005037587 U1 [0006]
• WO 2006/119828 [0030]
• WO 2003/000621 [0030]

Claims (15)

Use of a superabsorbent material to increase the heat capacity and / or improvement the heat transfer in heat storage. Use according to claim 1, wherein the heat storage a hermetic or non-hermetic heat storage is. Use according to one of claims 1 or 2, wherein the heat storage a subterranean geothermal storage is. Use according to one of the preceding claims, wherein the superabsorbent material is at least one superabsorbent includes organic polymer. Use according to claim 4, wherein the superabsorbent Material a mixture of at least one superabsorbent organic polymer and at least one bulk material is. Use according to claim 5, wherein the at least a bulk material is selected from soil, Sand, gravel, soil, clay, overburden, slag, rubble, excavation, and like. Use according to claim 4, wherein the superabsorbent Material a hybrid material of superabsorbent, organic Polymer having incorporated therein in copolymerized mineral constituents. Use according to one of claims 4 to 7, wherein the superabsorbent organic polymer is selected is from at least one of, possibly crosslinked, polyacrylic acid, Polymethacrylic acid, copolymers of acrylic acid and salts of acrylic acid (especially sodium acrylate, Potassium acrylate), polysaccharides, polyacrylamides, hydrogels, polyvinylpyrrolidone; Use of a superabsorbent organic Polymer comprising a crosslinked copolymer of acrylic acid and acrylic acid sodium or potassium salt mixed with selected from at least one bulk material Sand, gravel, soil, clay, overburden, slag, or rubble, to increase the heat capacity and / or to improve the heat transfer in heat storage. Use of a superabsorbent material comprising a hybrid material consisting of superabsorbent, organic Polymer comprising a crosslinked copolymer of acrylic acid and acrylic acid sodium or potassium salt with copolymerized therein Mineral components, to increase the heat capacity and / or to improve the heat transfer in Heat registers. Heat storage comprising at least one superabsorbent Material. A heat accumulator according to claim 11, wherein the superabsorbent material at least one superabsorbent organic Polymer includes. A heat accumulator according to claim 11 or 12, wherein the superabsorbent material is a mixture of at least one superabsorbent organic polymer and at least one bulk material is. A heat accumulator according to claim 11 or 12, wherein the superabsorbent material is a hybrid material of superabsorbent, organic polymer with polymerized or bound therein Mineral ingredients is. Heat accumulator according to one of claims 11 to 14, where the heat storage is a hermetic or non-hermetic Geothermal storage is.

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