HEAT STORAGE SYSTEM AND METHOD FOR HEAT STORAGE AND EXTRACTION

Description

[0001] The present invention relates to a heat storage system comprising a storage space, a heat storage medium in the storage space, and a removal device for removing heat from the heat storage medium. The removal device comprises a first solid-state arrangement in contact with the heat storage medium. Furthermore, the present invention relates to a method for heat storage and removal, in particular for heat storage and removal in a corresponding heat storage system.

[0002] EP 3 635 317 B1 describes a latent heat storage system and a method for operating the same. The known latent heat storage system comprises a storage chamber in the form of a latent heat storage device, wherein the storage chamber contains a storage medium with latent heat. To extract the heat from the storage medium within the storage chamber, a line leads from the outside to a heat exchanger within the storage chamber, while another line leads back from the heat exchanger out of the storage chamber. A feed pump is provided for conveying a heat transfer medium through the two lines and the heat exchanger.The heat exchanger forms a solid-state arrangement that is in contact with the storage medium within the storage space, so that the heat of the storage medium can be transferred via the solid-state arrangement of the heat exchanger to the heat transfer medium flowing through the heat exchanger, which can then be fed to a consumer or similar via the line leading out of the storage space.

[0003] The well-known latent heat storage system has proven itself effective, but its design is relatively complex and requires increased maintenance. Furthermore, the heat flow between the heat storage medium and the consumer can only be controlled or regulated to a limited extent, or with great effort, by adjusting the speed of the heat transfer medium pump.

[0004] GB 2506354 A describes a heat storage device comprising a storage chamber, a heat storage medium in the storage chamber, and a heating device in the form of a heat exchanger for heating the heat storage medium. Furthermore, a second heat exchanger is provided for heat extraction. The second heat exchanger comprises a first solid-state arrangement consisting of a housing and insulating material, and a second solid-state arrangement consisting of a heat transfer element and fluid lines. The second solid-state arrangement, which is in permanent contact with the first solid-state arrangement, can be rotated relative to the first solid-state arrangement to change the heat flow from the heat storage medium to the fluid lines.

[0005] It is an object of the present invention to further develop a heat storage system, in particular a latent heat storage system, such that it has a relatively simple and low-maintenance design and enables simple control or regulation of the heat flow from the storage medium to a consumer. Furthermore, the present invention is based on the object of providing a particularly simple method for heat storage and extraction, in particular a suitable method for operating the heat storage system according to the invention.

[0006] This object is achieved by the features specified in patent claims 1 and 9, respectively. Advantageous embodiments of the invention are the subject of the subclaims.

[0007] The heat storage system according to the invention has a storage space. The storage space is preferably designed to be closed, without being integrated into a circuit. A heat storage medium is accommodated in the storage space of the heat storage system. The heat storage medium is preferably a latent heat storage medium or a phase-change material, such as a salt or salt mixture, so that the heat storage system is particularly preferably designed as a liquid salt storage system. The heat storage system further comprises a heating device for heating the heat storage medium. In addition, the heat storage system has a removal device for removing heat from the heat storage medium within the storage space.The extraction device comprises a first solid-state arrangement in contact with the heat storage medium within the storage space, such that heat can be transferred from the heat storage medium to the first solid-state arrangement. The first solid-state arrangement can be formed either by a single solid-state body or by two or more solid-state bodies that are interconnected. In the case of two or more interconnected solid-state bodies, these are preferably interconnected in such a way that heat transfer between all solid-state bodies can occur through solid-state contact. In a first solid-state arrangement comprising two or more solid-state bodies, only one of the solid-state bodies can be in contact with the heat storage medium.While the heat storage system according to EP 3 635 317 B1 provides only a first solid-state arrangement in the form of a heat exchanger, including supply and discharge lines, within the storage space, which interacts directly with a heat transfer medium flowing in the heat exchanger, the extraction device in the heat storage system according to the invention further comprises a second solid-state arrangement. The second solid-state arrangement can also be formed by a single solid body or two or more interconnected solid bodies. In the case of two or more interconnected solid bodies, the solid bodies are preferably interconnected in such a way that heat transfer between all solid bodies can occur through solid-state contact between these solid bodies.In order to adjust, regulate, or control a heat flow between the first solid-state arrangement and the second solid-state arrangement, from which the heat can ultimately be supplied to a consumer, in a particularly simple and low-maintenance manner, the first and second solid-state arrangements interact in such a way that a solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be changed, increasing or decreasing a heat flow from the first solid-state arrangement to the second solid-state arrangement. Thus, the amount of heat that can be transferred per unit of time can be increased or decreased by changing the solid-state contact.Only a very simple mechanism is required to change the solid-state contact between the first solid-state arrangement and the second solid-state arrangement and thus the heat flow starting from the heat storage medium via the first solid-state arrangement to the second solid-state arrangement, without the need for a maintenance-intensive heat exchanger with a heat transfer medium flowing inside. The extraction device is designed such that the solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be eliminated and created. Accordingly, in this embodiment, the solid-state contact can be eliminated in order to reduce the heat flow as much as possible. If, on the other hand, an increased heat flow is required, the solid-state contact between the first and second solid-state arrangement can be created by the extraction device.Furthermore, the removal device is designed such that the solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be or is created indirectly. Indirect creation of the solid-state contact is understood to mean the interposition of one or more solid bodies that have both a solid-state contact with the first solid-state arrangement and a solid-state contact with the second solid-state arrangement.

[0008] In an advantageous embodiment of the heat storage system according to the invention, the extraction device is designed such that the solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be changed stepwise or incrementally. This embodiment is particularly advantageous when, depending on the application, a continuous change in the solid-state contact is not required. Alternatively, however, the extraction device can also be designed such that the solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be changed continuously.

[0009] In a particularly advantageous embodiment of the heat storage system according to the invention, the removal device is designed such that the solid-state contact between the first solid-state arrangement and the second solid-state arrangement can be varied by changing the number of solids that are in contact with both the first and the second solid-state arrangement. This embodiment is preferred in that the first and second solid-state arrangements generally do not need to be moved relative to one another; rather, only the mediating solids need to be transferred into a position in which they are in contact with both the first and the second solid-state arrangement, or not.In the simplest case, only one mediating solid body would be required, whereby several mediating solid bodies are preferred if different heat flows between the first solid body arrangement and the second solid body arrangement are to be achieved or adjusted.

[0010] In a further particularly advantageous embodiment of the heat storage system according to the invention, the first solid-state arrangement and the second solid-state arrangement each have at least one surface via which the solid-state contact can be or is indirectly generated in order to achieve the heat flow from the first solid-state arrangement to the second solid-state arrangement. To prevent heat loss at the surface of the first solid-state arrangement due to convection, both the surface of the first solid-state arrangement and the surface of the second solid-state arrangement are arranged in a closed and / or evacuated contact space. In particular, in an evacuated contact space, the vacuum within the contact space prevents convection.

[0011] In a preferred embodiment of the heat storage system according to the invention, a third solid-state arrangement is provided, which has at least one movable solid body. Like the first and second solid-state arrangements, the third solid-state arrangement can also be formed by just one movable solid body or by two or more movable solid bodies. In contrast to the first and second solid-state arrangements, a connection between the two or more movable solid bodies such that a heat flow can be achieved solely through solid-state contact between them is neither preferred nor necessary.The at least one movable solid body can be moved relative to the first and second solid body arrangements from a first position in which the movable solid body is in contact with none of the surfaces or with the surface of only one of the first and second solid body arrangements, to a second position in which the movable solid body is in contact with the surfaces of the first and second solid body arrangements. A drive device is preferably provided for moving the at least one movable solid body, wherein the drive device particularly preferably comprises a drive motor, for example an electric motor. In order to create a particularly simple mechanism, the at least one movable solid body is preferably displaceable in translation from the first to the second position and vice versa.In the simplest embodiment, only one movable solid body can be provided to cancel the indirect solid-body contact in the first position and create it in the second position. As already indicated above, however, in this embodiment it is preferred if the third solid-body arrangement has at least two or more movable solid bodies that can be moved independently of one another into the first and / or second positions in order to be able to regulate the heat flow from the first solid-body arrangement to the second solid-body arrangement in three or more stages.

[0012] In a further advantageous embodiment of the heat storage system according to the invention, the at least one movable solid body of the third solid body arrangement is arranged in the closed and / or evacuated contact space in order to be able to come into contact with or be in contact with the surfaces of the first solid body arrangement and the second solid body arrangement.

[0013] To simplify the construction of the heat storage system, in particular the removal device of the heat storage system, the first solid-state arrangement and the second solid-state arrangement are arranged immovably relative to one another in a further preferred embodiment of the heat storage system according to the invention, especially since relative movement between the first and second solid-state arrangements is unnecessary thanks to the third solid-state arrangement with its at least one movable solid body. Alternatively or additionally, the surfaces of the first and second solid-state arrangements are permanently spaced apart from one another without coming into direct contact with one another.

[0014] In a further particularly preferred embodiment of the heat storage system according to the invention, the surface of the first solid-body arrangement has at least one first surface section and the surface of the second solid-body arrangement has at least one second surface section, which are assigned to one another and inclined to one another, while the movable solid body of the third solid-body arrangement is wedge-shaped in such a way that in the second position it is in flat contact with the first and second surface sections of the first and second solid-body arrangement.Thanks to the inclination of the first and second surface sections relative to one another on the one hand and the wedge shape of the movable solid body of the third solid body arrangement on the other hand, a short movement of the movable solid body from the first position to the second position can achieve large-area contact with both the first solid body arrangement and the second solid body arrangement in order to increase the heat flow between the first solid body arrangement and the second solid body arrangement. In this embodiment, it is preferred if the mutually associated surface sections, namely the first surface section on the one hand and the associated second surface section on the other hand, enclose an angle of less than 60° or less than 10°. Furthermore, it is preferred if the surface of the first and / or second solid body arrangement is shaped like a lateral surface of a pyramid or a truncated pyramid.Thus, a corresponding pyramid or truncated pyramid can have three, four or more sides and a corresponding number of associated movable solid bodies of the third solid body arrangement in order to achieve a corresponding gradation of the solid body contact or the heat flow between the first and second solid body arrangement.

[0015] In a further advantageous embodiment of the heat storage system according to the invention, the first solid-state arrangement has a solid body on the output side for achieving indirect solid-state contact with the second solid-state arrangement. Furthermore, the first solid-state arrangement has at least one strut protruding into the storage space for contacting the storage medium. It is preferred if the at least one strut is in direct contact with the solid body on the output side, which may, for example, have the aforementioned surface. Furthermore, it is preferred if two or more such struts protruding into the storage space are provided, wherein the struts are preferably arranged symmetrically with respect to the storage space or its shape.To facilitate heat transfer from the storage medium to the strut of the first solid-state arrangement, the surface area of ​​the strut protruding into the storage space is increased by arranging or attaching protruding ribs or vanes to the strut. It has proven advantageous if the ribs or vanes are each formed by an elongated element that is bent multiple times, possibly in one plane.

[0016] In a further preferred embodiment of the heat storage system according to the invention, the second solid-state arrangement comprises a solid body for forming the inside of a fluid container or a fluid line for heating a fluid. In this way, the heat can leave the extraction device of the heat storage system and be transferred via the inside, for example a base, a fluid container, or a fluid line, to the fluid within the fluid container or fluid line, so that after the heat has been stored in the heat storage medium of the storage space, it can then be consumed. One can therefore also speak of an output-side solid body of the second solid-state arrangement. In this case, the solid body preferably forms the inside of the boiler of an evaporator, so that the fluid evaporated in the boiler can drive a turbine or the like, preferably as pressurized steam.

[0017] In a further advantageous embodiment of the heat storage system according to the invention, the heating device for heating the heat storage medium is an inductive heating device which can convert a current, in particular a high-frequency alternating current, into thermal energy by induction, which makes the heat storage system particularly interesting for the storage of renewably generated electricity.

[0018] In a further advantageous embodiment of the heat storage system according to the invention, the heating device has at least one heatable heating strut extending into the storage space. As with the strut of the first solid-state arrangement extending into the storage space, it is also preferred for the heating strut to have protruding ribs or vanes arranged or attached thereto, which, moreover, are preferably formed by an elongated element that is bent multiple times, optionally in one plane, in order to enlarge the surface of the heating device that interacts with or comes into contact with the heat storage medium. Furthermore, it is preferred in this embodiment if two or more heating struts are provided, wherein the heating struts are also preferably arranged symmetrically with respect to the cross-section of the storage space.It has also been shown that it is advantageous if the struts of the first solid-state arrangement and the heating struts of the heating device extend into the storage space in opposite directions or height directions of the heat storage system, wherein in this context it has also proven advantageous if the struts or heating struts extending into the storage space do not touch the opposite boundary of the storage space, but particularly preferably have free ends.

[0019] To avoid energy or heat losses in the area of ​​the heating device, in a further preferred embodiment of the heat storage system according to the invention, the at least one heating strut of the heating device extends from the storage space into a sealed and / or evacuated induction chamber, in which the heating strut interacts with an inductor, preferably a coil, to heat the heating strut. Thanks to the arrangement of the heating strut and the inductor in the sealed and / or evacuated induction chamber, heat losses due to convection are largely or entirely avoided.

[0020] In a further advantageous embodiment of the heat storage system according to the invention, the heat storage system is designed as a latent heat storage system with a phase-change material as the heat storage medium. Thanks to the phase-change material used, the heat storage medium can store very large amounts of heat within a small temperature range around a phase change, which preferably occurs between solid and liquid. It is preferred if the phase-change material is a salt or salt mixture. Therefore, in this embodiment, it is particularly preferred if the storage space with the heat storage medium contained therein forms a liquid-salt heat storage device.

[0021] As already explained above, in a further preferred embodiment of the heat storage system according to the invention, the first solid-state arrangement and / or the second solid-state arrangement and / or the third solid-state arrangement are formed by one or more solids consisting of or made of metal or a metal alloy in order to achieve a particularly high thermal conductivity of the solids and, consequently, a particularly high heat flow between the first solid-state arrangement and the second solid-state arrangement during solid-state contact. Non-ferrous metals, such as copper or copper alloys, are particularly preferred here.

[0022] Since solid-state contact between the first solid-state arrangement and the second solid-state arrangement beyond the variable solid-state contact described above is hardly avoidable in the interests of a compact design of the heat storage system, in a further advantageous embodiment of the heat storage system according to the invention, in addition to the variable solid-state contact, there is permanent solid-state contact between the first and second solid-state arrangements via at least one further component of the heat storage system, wherein the at least one further component of the heat storage system is preferably designed as an insulator and / or has a lower thermal conductivity than the at least one solid body of the first and second solid-state arrangement. For this purpose, the at least one further component is preferably not made of metal.

[0023] The method according to the invention serves to store and extract heat while achieving the advantages mentioned above with reference to the heat storage system. It is preferred if the method serves to operate a heat storage system of the type according to the invention.The method comprises the method steps of providing a heat storage medium in contact with a first solid-state arrangement and a second solid-state arrangement, heating the heat storage medium by a heating device, changing a solid-state contact between the first solid-state arrangement and the second solid-state arrangement while increasing or reducing a heat flow from the first solid-state arrangement to the second solid-state arrangement, wherein the solid-state contact between the first solid-state arrangement and the second solid-state arrangement is canceled and created indirectly with the interposition of one or more solids, and removing heat from the second solid-state arrangement.

[0024] In a preferred embodiment of the method according to the invention, the solid-state contact between the first solid-state arrangement and the second solid-state arrangement is changed stepwise or continuously.

[0025] In a particularly advantageous embodiment of the method according to the invention, the solid-state contact between the first solid-state arrangement and the second solid-state arrangement is changed by changing a number of solids that are in contact with both the first and the second solid-state arrangement.

[0026] According to a further preferred embodiment of the method according to the invention, the solid-state contact between the first solid-state arrangement and the second solid-state arrangement is changed by changing the size of a contact area between the first solid-state arrangement and the second solid-state arrangement.

[0027] In a particularly advantageous embodiment of the method according to the invention, heat is removed from the second solid-state arrangement by heating a fluid contacting the second solid-state arrangement.

[0028] In a particularly preferred embodiment of the method according to the invention, the solid-state contact is changed by means of a drive device, preferably an electrical and / or hydraulic drive device.

[0029] With regard to the advantages of the embodiment variants of the method according to the invention and further embodiments thereof, reference is made to the preceding description of the heat storage system according to the invention, from which the corresponding advantages and embodiment variants of the method according to the invention will readily become apparent to the person skilled in the art, without the corresponding features having to be repeated here.

[0030] The invention will be explained in more detail below using an exemplary embodiment with reference to the accompanying drawings. They show: Fig. 1 a perspective view of an embodiment of the heat storage system according to the invention in a sectional view, Fig. 2 a partially exploded view of the heat storage system from Fig. 1 , Fig. 3 a top view of the storage space of the heat storage system from the Fig. 1 and 2 in a sectional view, Fig. 4 a partial, enlarged view of a strut or heating strut from the Fig. 1 to 3 in perspective view, Fig. 5 a side view of the heat storage system from the Fig. 1 to 3 in a sectional view with the movable solid bodies in a first position and Fig. 6 the cross-sectional view from Fig. 5 with the movable solid bodies in a second position.

[0031] The Fig. 1 to 6show an embodiment of the heat storage system 2 according to the invention for carrying out the method according to the invention for heat storage and extraction. In the figures, the opposing height directions 4, 6, the opposing width directions 8, 10, and the opposing length directions 12, 14 of the heat storage system 2 are indicated by corresponding arrows, wherein the heat storage system 2 has a central height axis 16 extending in the height directions 4, 6.

[0032] The heat storage system 2 has a housing 18 composed of several housing parts or sections. A storage space 20 is formed within the housing 18. The storage space 20 is essentially cylindrical, with its longitudinal axis extending in the vertical direction 4, 6 and preferably coinciding with the vertical axis 16 of the housing 18. The storage space 20 is enclosed by the housing 18. Thus, the storage space 20 is not integrated into any circuit, and inflow and / or outflow lines are preferably not provided. The storage space 20 serves to accommodate a heat storage medium; for reasons of clarity, the heat storage medium within the storage space 20 has been omitted from the figures. Although not shown, the storage space 20 is preferably at least 95% or completely filled with the heat storage medium.The storage space 20 is delimited by an inner housing part 22 and an outer housing part 24 of the housing 18 surrounding the inner housing part, wherein the inner and / or outer housing part 22 or 24 can in turn be designed in one, two or more parts and accordingly form a storage space housing 22, 24.

[0033] A removal device 26 for removing heat from the heat storage medium is arranged in the vertical direction 4 above the storage space 20 and outside the at least inner housing part 22. The removal device 26 comprises a first solid-state arrangement 28, a second solid-state arrangement 30, and a third solid-state arrangement 32, which will be described in more detail below.

[0034] The first solid-state arrangement 28 is in contact with the heat storage medium within the storage space 20. The first solid-state arrangement 28 has an output-side solid-state 34 for achieving the solid-state contact with the second solid-state arrangement 30, which will be described in more detail later. The output-side solid-state 34 extends essentially in the width and length directions 8 to 14 and is arranged with its side facing downward in the height direction 6 on the side of the inner housing part 22, or optionally the outer housing part 24, facing upward in the height direction 4. In addition, the first solid-state arrangement 28 has further solids, namely a plurality of struts 36 projecting downward in the height direction 6 into the storage space 20 for contacting the storage medium within the storage space 20.With their end pointing upward in the vertical direction 4, the struts 36 are directly connected to the output-side solid body 34 of the first solid-body arrangement 28, while the end of the struts 36 pointing downward in the vertical direction 6 is spaced from the inner housing part 22. In order to reach the storage space 20 from the output-side solid body 34, the struts 36 extend through corresponding openings 38 in the inner housing part 22.

[0035] As from Fig. 3As can be seen, a total of five struts 36 are provided, of which a central strut 36 extends along the vertical axis 16, while the remaining four struts 36 are arranged symmetrically around the vertical axis 16. In order to ensure the largest possible contact between the first solid body arrangement 28 and the heat storage medium within the storage space 20, protruding ribs or wings 40 are arranged on the struts 36, which are preferably formed by an elongated element 42 that is bent several times, possibly in one plane. Fig. 1 and 2 However, only some of the actually provided ribs / wings 40 are shown to increase clarity, while the actual number essentially consists of the Fig. 3 and 4 is evident.

[0036] The output-side solid body 34 has, on its side facing away from the struts 36 and essentially pointing in the height direction 4, a surface 44 which serves to create the solid body contact between the first and second solid body arrangements 28, 30, as will be described in more detail below. Fig. 2 As can be seen, the surface 44 of the output-side solid body 34 is shaped like the surface of a pyramid, possibly a truncated pyramid, with the height axis of the pyramid extending essentially in the height directions 4, 6, here along the height axis 16. In the illustrated embodiment, the pyramid has a total of four side surfaces, so that the surface 44 is correspondingly divided into four first surface sections 46 to 52.

[0037] The second solid-state arrangement 30 is essentially formed by a solid-state body 54, which is arranged in the height direction 4 above the output-side solid-state body 34 of the first solid-state arrangement 28 and at a distance therefrom, and extends essentially in the width and length directions 8 to 14 in order to be arranged in alignment with the output-side solid-state body 34 of the first solid-state arrangement 28 in the height direction 4, 6. On its side facing the output-side solid-state body 34 in the height direction 6, the output-side solid-state body 54 in turn has a surface 56, via which the solid-state contact with the first solid-state arrangement 28, described in more detail below, is to be created. One can therefore also speak of an input-side solid-state body 54.The surface 56 of the second solid-state arrangement 30 is also shaped in the manner of the lateral surface of a pyramid, possibly a truncated pyramid, wherein the pyramid or truncated pyramid also has four sides in this case, so that the surface 56 is correspondingly divided into four second surface sections 58 to 64.

[0038] The solid body 34 of the first solid body arrangement 28 and the output-side solid body 54 of the second solid body arrangement 30 are arranged in a fixed and immovable manner relative to one another in such a way that the first surface section 46 and the second surface section 58, the first surface section 48 and the second surface section 60, the first surface section 50 and the second surface section 62 and the first surface section 52 and the second surface section 64 are opposite one another in the height direction 4, 6 and are thus assigned to one another and, moreover, are inclined relative to one another, wherein the mutually assigned first and second surface sections each preferably enclose an angle α of less than 60° or less than 10°.

[0039] On its side facing away from the first solid-state arrangement 28, the solid body 54 of the second solid-state arrangement 30 has a side that forms an inner side 66 of a fluid container (not shown in detail) or a fluid line (not shown in detail) for heating a fluid, so that the heat extracted from the heat storage medium within the storage space 20 via the extraction device 26 can be transferred to the fluid of a consumer on the inner side 66. Thus, the solid body 54 can also be referred to as an output-side solid body 54. The inner side 66 is preferably the inner side 66 of the boiler of an evaporator in order to evaporate or heat the fluid and, if necessary, feed it to a turbine driven by the steam.

[0040] The solid bodies 34, 54 of the first and second solid-body arrangements 28, 30, in particular their surfaces 44, 56, are arranged in a contact space 68 formed above the storage space 20 and within the housing 18. The contact space 68 is delimited in the height direction 4 and in the width and length directions 8 to 14 by an upper housing part 70 of the housing 18, and in the height direction 6 essentially by the outer housing part 24, optionally also the inner housing part 22, wherein the contact space 68 is closed off so that it is not integrated into an air or fluid circuit or the like. Furthermore, the contact space 68 is evacuated to prevent heat loss at the output-side solid body 34 of the first solid-body arrangement 28 due to convection at the surface 44.

[0041] In order to be able to adjust or change a heat flow from the first solid body arrangement 28, i.e. starting from the heat storage medium within the storage space 20 via the struts 36 and the output-side solid body 34, to the second solid body arrangement 30, i.e. to the solid body 54 and ultimately to the inner side 66, a solid body contact between the first solid body arrangement 28 and the second solid body arrangement 30 can be changed by increasing or decreasing the said heat flow from the first solid body arrangement 28 to the second solid body arrangement 30. In the specific embodiment according to the Fig. 1 to 6The solid-state contact between the first solid-state arrangement 28 and the second solid-state arrangement 30 can be varied stepwise or incrementally, namely by varying the number of solids that are in contact with both the first and the second solid-state arrangement 28, 30, as will be explained in more detail below. The solid-state contact between the first solid-state arrangement 28 and the second solid-state arrangement 30 can also be eliminated and created by the removal device 26, wherein the solid-state contact can be created or created indirectly via the third solid-state arrangement 32 described below.

[0042] As already indicated above, in the illustrated embodiment of the heat storage system 2, a third solid-state arrangement 32 is provided, which serves to gradually or incrementally change a solid-state contact between the first solid-state arrangement 28 and the second solid-state arrangement 30, thereby increasing or decreasing a heat flow from the first solid-state arrangement 28 to the second solid-state arrangement 30. The third solid-state arrangement 32 has a plurality of movable solids, with four movable solids 72 to 78 being provided in the illustrated embodiment. The third solid-state arrangement 32, or at least its movable solids 72 to 78, are arranged within the previously described contact space 68.While the first solid-state arrangement 28 and the second solid-state arrangement 30, in particular their solid bodies 34 and 54, are arranged immovably relative to one another on the housing 18 and their surfaces 44 and 56 are permanently spaced apart from one another, the movable solid bodies 72 to 78 are movable relative to the first and second solid-state arrangements 28, 30, in particular relative to the two solid bodies 34 and 54. More precisely, the movable solid bodies 72 to 78 are movable transversely to the vertical axis 16 relative to the solid bodies 34, 54 and are thereby translationally movable or displaceable, wherein a drive device (not shown in detail) is assigned to the movable solid bodies 72 to 78 for this purpose. The drive device preferably has an electric motor or hydraulic drive.The movable solid bodies 72 to 78 are also each wedge-shaped or wedge-like, so that they have a surface pointing downwards in the height direction 6 and a surface pointing upwards in the height direction 4, which are inclined to one another thanks to the wedge shape, wherein the angle of inclination preferably corresponds to the previously described angle α between the mutually associated first and second surface sections 46 to 52 and 58 to 64, respectively.

[0043] Thus, the movable solid body 72 can be moved from its Fig. 1 and 5 shown first position, in which the movable solid body 72 is not in contact with any of the surface sections 46 and 58 of the surfaces 44 and 56 or with only one of the surface sections 46 or 58, in the width direction 8 in the Fig. 6shown second position, in which the movable solid body 72 is in planar contact with both surface sections 46 and 58 of the surfaces 44 and 56 of the first and second solid body arrangements 28, 30, so that the indirect solid body contact between the first solid body arrangement 28 and the second solid body arrangement 30 via the movable solid body 72 was changed in one step or stage by increasing the heat flow from the first solid body arrangement 28 to the second solid body arrangement 30.The further movable solid bodies 74, 76 and 78 can be moved into the first and / or second position independently of the movable solid body 72 and independently of one another, wherein the movable solid body 74 is movable or translationally movable or displaceable in the length direction 12 from the first position to the second position, the movable solid body 76 is movable in the width direction 10 from the first position to the second position and the movable solid body 78 is movable or translationally movable or displaceable in the length direction 14 from the first position to the second position.The more of the movable solid bodies 72 to 78 are arranged in the second position, the greater the possible heat flow between the first solid body arrangement 28 and the second solid body arrangement 30, wherein the change in the indirect solid body contact and thus also the change in the heat flow can take place stepwise or in stages depending on the number of movable solid bodies 72 to 78 arranged in the second position.

[0044] In principle, the heat storage system 2 can also be designed such that the solid-state contact between the first solid-state arrangement 28 and the second solid-state arrangement 30 can be continuously changed.

[0045] In order to be able to introduce the heat to be stored into the heat storage system 2, the heat storage system 2 further comprises a heating device 80 for heating the heat storage medium within the storage space 20, wherein the heating device 80 is an inductive heating device 80. Thus, the heating device 80 has, in particular, a plurality of inductively heatable heating struts 82 extending into the storage space 20, which extend essentially in the height directions 4, 6. Specifically, the heating struts 82 extend, on the one hand, through an opening 84 at the bottom of the housing parts 22, 24 in the height direction 4 into the storage space 20, without their ends pointing upwards in the height direction 4 adjoining the inner housing part 22, however. Rather, the ends of the heating struts 82 are spaced apart from the inner housing part 22 in the height direction 4, 6, so that they can also be referred to as free ends.In the opposite height direction 6, the heating struts 82 extend through the aforementioned opening 84 into an induction chamber 86, which is a closed and / or evacuated chamber in which not only the heating strut 82 but also the inductor 88 associated with the heating strut 82, for example an electrical coil, is arranged in order to be able to heat the heating strut 82 by means of a high-frequency alternating current.

[0046] In order to achieve the largest possible contact surface between the heating device 80 and the heat storage medium within the storage space 20, the ribs or wings 40 previously described with reference to the struts 36 of the first solid body arrangement 28 are also provided on the heating struts 82, which are arranged on the heating struts 82 and are formed by a multiply bent elongated element 42, so that in this respect the representation in Fig. 4applies equally to the struts 36 and the heating struts 82.

[0047] The closed and / or evacuated induction chambers 86 are essentially delimited by a lower housing part 90 of the housing 18 and, in the vertical direction 4, by the inner and / or outer housing parts 22, 24. Together with the upper housing part 70, the lower housing part 90, in which the inner housing part 22 and the outer housing part 24 are accommodated, forms the outer shell of the heat storage system 2.

[0048] As already explained above, the first solid-state arrangement 28, the second solid-state arrangement 30, and the third solid-state arrangement 32 are formed by one or more solids, wherein said solids are preferably made of a metal or a metal alloy in order to ensure high thermal conductivity on the part of said solid-state arrangements 28, 30, 32. Thus, in the illustrated embodiment, in particular the output-side solid 34, the struts 36, and the ribs or vanes 40 of the first solid-state arrangement 28, the solid 54 of the second solid-state arrangement 30, and the movable solids 72, 74, 76, 78 of the third solid-state arrangement 32 are made of a metal or a metal alloy, whereby this should also apply correspondingly to the heating struts 82 and the ribs or vanes 40 arranged thereon.In particular, for the struts 36 and / or the heating struts 82, it is advisable to manufacture them from steel, thus ensuring good thermal conductivity on the one hand and chemical resistance to the heat storage medium within the storage space 20 on the other. For the movable solid bodies 72, 74, 76, 78, a non-ferrous metal, preferably copper or a copper alloy, can be considered as a material, whereas the solid bodies 34 and / or 54 could be made from steel or also from a non-ferrous metal such as copper or a copper alloy.

[0049] While the metallic solid bodies of the solid-state arrangements 28, 30, 32 have a particularly high thermal conductivity, at least the outer housing part 24, in which the inner housing part 22 with the storage space 20 is accommodated, has a material that has a significantly lower thermal conductivity than the material of the aforementioned solid-state arrangements 28, 30, 32. The same can, in principle, also apply to the inner housing part 22 directly facing the storage space 20; however, the inner housing part 22 can also be primarily designed to achieve a certain resistance of the housing to the heat storage medium within the storage space 20, so that the inner housing part 22 can, in principle, also be made of steel.

[0050] From the presentation in the Fig. 1 , 5 and 6It can be seen that, in addition to the previously described variable solid-state contact between the first solid-state arrangement 28 and the second solid-state arrangement 30 via the third solid-state arrangement 32, there is also a permanent solid-state contact between the first and second solid-state arrangements 28, 30 via at least one further component of the heat storage system 2, here via the housing 18. Specifically, the output-side solid-state 34 of the first solid-state arrangement 28 is in solid-state contact indirectly with the output-side solid-state 54 of the second solid-state arrangement 30 via the outer housing part 24, the lower housing part 90, and the upper housing part 70, which is a permanent solid-state contact.Since the outer housing part 24, and possibly also the lower housing part 90 and / or the upper housing part 70, have a lower thermal conductivity than the two solid bodies 34, 54 of the first and second solid-body arrangements 28, 30, or are even designed as insulators, this permanent solid-body contact is not particularly significant with regard to any heat loss. Additionally, the solid body 54 of the second solid-body arrangement 30 is supported or arranged on the upper housing part 70 via an insulating component, which has a further reduced thermal conductivity compared to the upper housing part 70.

[0051] Finally, it should be mentioned that the heat storage system 2 is preferably designed as a latent heat storage system with a so-called phase-change material as the heat storage medium. The heat storage medium is preferably a salt or a salt mixture, with the heat transfer to the first solid-state arrangement 28 preferably occurring during the transition from a liquid state to a solid state of the salt or salt mixture, which is why this can also be referred to as a liquid salt storage system. List of reference symbols

[0052] 2 Heat storage system 4 Height direction 6 Height direction 8 Width direction 10 Width direction 12 Length direction 14 Length direction 16 Height axis 18 Housing 20 Storage space 22 Inner housing part 24 Outer housing part 26 Removal device 28 First solid body arrangement 30 Second solid body arrangement 32 Third solid body arrangement 34 Solid body 36 Struts 38 Openings 40 Ribs / wings 42 Element 44 Surface 46 First surface section 48 First surface section 50 First surface section 52 First surface section 54 Solid body 56 Surface 58 Second surface section 60 Second surface section 62 Second surface section 64 Second surface section 66 Interior 68 Contact space 70 Upper housing part 72 Movable solid body 74 Movable solid body 76movable solid body 78movable solid body 80heating device 82heating struts 84opening 86induction chamber 88inductor 90lower housing part 92component αAngle

Claims

1. A heat storage system (2) comprising a storage space (20), a heat storage medium in the storage space (20), a heating device (80) for heating the heat storage medium and an extraction device (26) for extracting heat from the heat storage medium, the extraction device (26) comprising a first solid body arrangement (28) contacting the heat storage medium and a second solid body arrangement (30), wherein a solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) can be modified thereby increasing or decreasing a heat flow from the first solid body arrangement (28) to the second solid body arrangement (30), characterized in that the solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) can be eliminated and is or can be established indirectly by interposing one or more solid bodies (72, 74, 76, 78).

2. The heat storage system (2) according to claim 1, characterized in that the solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) can be modified incrementally or continuously, or / and can be modified by modifying a quantity the solid bodies (72, 74, 76, 78) contacting the first and the second solid body arrangements (28, 30).

3. The heat storage system (2) according to any one of the claims 1 or 2, characterized in that the first solid body arrangement (28) and the second solid body arrangement (30) each comprise at least one surface (44, 56) by means of which the solid body contact is or can be established indirectly, wherein the surfaces (44, 56) are preferably disposed in a closed or / and evacuated contact space (68).

4. The heat storage system (2) according to claim 3, characterized in that a third solid body arrangement (32) having at least one displaceable solid body (72; 74; 76; 78) is provided and can be displaced or translationally shifted relative to the first and second solid body arrangements (28, 30) from a first position in which the displaceable solid body (72; 74; 76; 78) does not contact any of the surfaces (44, 56) or contacts the surface of only one of the first and second solid body arrangements (28; 30) into a second position in which the displaceable solid body (72; 74; 76; 78) contacts the surfaces (44, 56) of the first and second solid body arrangement (28, 30), wherein the third solid body arrangement (32) preferably comprises at least two displaceable solid bodies (72, 74, 76, 78) displaceable independently of each other into the first or / and second position, or / and the at least one displaceable solid body (72; 74; 76; 78) is preferably disposed in the closed or / and evacuated contact space (68), and the first and second solid body arrangements (28, 30) are particularly preferably disposed fixed relative to each other or / and the surfaces (44, 56) thereof are permanently spaced apart from each other.

5. The heat storage system (2) according to claim 4, characterized in that the surface (44) of the first solid body arrangement (28) comprises at least one first surface segment (46) and the surface (56) of the second solid body arrangement (30) comprises at least one second surface segment (58) associated with each other and inclined relative to each other, and the displaceable solid body (72) of the third solid body arrangement (32) is implemented having a wedge shape, such that said body makes flat contact with the first and second surface segments (46, 58) of the first and second solid body arrangements (28, 30) in the second position, wherein the surface segments (46, 58) associated with each other preferably enclose an angle (α) of less than 60° or less than 10°, and the surface (44; 56) of the first or / and second solid body arrangement (28; 30) is particularly preferably shaped in the manner of a lateral surface of a pyramid or a frustrum of a pyramid.

6. The heat storage system (2) according to any one of the preceding claims, characterized in that the first solid body arrangement (28) comprises an outlet-side solid body (34) for establishing solid body contact with the second solid body arrangement (30) and comprises at least one strut (36) protruding into the storage space (20) for contacting the storage medium, wherein protruding ribs or fins (40) are preferably disposed on the strut (36) and implemented particularly preferably by a multiply curved, elongated element (42), optionally in one plane, or / and the second solid body arrangement (30) comprises a solid body (54) for implementing the inner side (66) of a fluid container, preferably for implementing the inner side of the boiler of an evaporator, or comprises a fluid line for heating a fluid.

7. The heat storage system (2) according to any one of the preceding claims, characterized in that the heating device (80) is an inductive heating device (80) or the heating device (80) comprises at least one heatable heating strut (82) extending into the storage space (20) and preferably extending out of the storage space (20) into a closed or / and evacuated induction space (86) in which the heating strut (82) interacts with an inductor (88).

8. The heat storage system (2) according to any one of the preceding claims, characterized in that the heat storage system (2) is implemented as a latent heat storage system (2) having a phase change material as the heat storage medium, wherein the heat storage medium is preferably a salt or a salt mixture, or / and the first solid body arrangement (28) or / and the second solid body arrangement (30) or / and the third solid body arrangement (32) is implemented by one or more solid bodies made of metal, or / and in addition to the modifiable solid body contact, a permanent solid body contact is present between the first and second solid body arrangements (28, 30) by means of at least one further component (92) of the heat storage system (2) preferably implemented as an insulator or / and having a lower thermal conductivity than the at least one solid body of the first and second solid body arrangements (28, 30).

9. A method for storing and extracting heat, preferably for operating a heat storage system (2) according to any one of the claims 1 through 8, having the method steps providing a heat storage medium contacting a first solid body arrangement (28) and a second solid body arrangement (30), heating the heat storage medium by a heating device (80), modifying a solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) thereby increasing or decreasing a heat flow from the first solid body arrangement (28) to the second solid body arrangement (30),wherein the solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) is eliminated and established indirectly by interposing one or more solid bodies (72, 74, 76, 78), and extracting heat at the second solid body arrangement (30).

10. The method according to claim 9, characterized in that the solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) can be modified incrementally or continuously, or / and can be modified by modifying a quantity of the solid bodies (72, 74, 76, 78) contacting the first and the second solid body arrangements (28, 30), or / and by modifying the size of a contact surface between the first solid body arrangement (28) and the second solid body arrangement (30), or / and heat is extracted at the second solid body arrangement (30) by heating a fluid contacting the second solid body arrangement (30).