HEAT STORAGE SYSTEM AND METHOD FOR STORING AND EXTRACTING HEAT
20230258413 · 2023-08-17
Assignee
Inventors
Cpc classification
Y02E60/14
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F28D20/028
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D20/021
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
The present invention relates to a heat storage system (2) comprising a storage space (20), a heat storage medium in the storage space (20), 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. The extraction device (26) further comprises 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 by increasing or decreasing a heat flow from the first solid body arrangement (28) to the second solid body arrangement (30). The present invention further relates to a method for storing and extracting heat.
Claims
1. A heat storage system (2) comprising a storage space (20), a heat storage medium in the storage space (20), 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, characterized in that the extraction device (26) further comprises 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 by increasing or decreasing a heat flow from the first solid body arrangement (28) to the second solid body arrangement (30).
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 eliminated and established, or/and is or can be established directly or indirectly, or/and can be modified by modifying a quantity of 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).
3. The heat storage system (2) according to any one of the claim 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 directly or 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 (a) 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 an optionally inductive heating device (80) is provided for heating the heat storage medium, wherein the heating device (80) preferably comprises at least one heatable heating strut (82) extending into the storage space (20) and particularly 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), modifying a solid body contact between the first solid body arrangement (28) and the second solid body arrangement (30) by increasing or decreasing a heat flow from the first solid body arrangement (28) to the second solid body arrangement (30), 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 eliminated and established, or/and is established directly or indirectly, or/and can be modified by modifying a quantity of 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).
Description
[0034] The invention is explained in greater detail below, using example embodiments with reference to the attached drawings. Shown are:
[0035]
[0036]
[0037]
[0038]
[0039]
[0040]
[0041]
[0042] The heat storage system 2 comprises a housing 18 comprising a plurality of housing parts or segments. A storage space 20 is implemented within the housing 18. The storage space 20 is substantially cylindrical in design, wherein the longitudinal axis thereof extends in the height direction 4, 6 and is preferably identical to the height axis 16 of the housing 18. The storage space 20 is closed off by the housing 18. The storage space 20 is thus not integrated in any circuit and inflows or/and outflows are preferably not provided. The storage space 20 serves for receiving a heat storage medium, wherein the heat storage medium within the storage space 20 is not depicted in the figures for reasons of clarity. The storage space 20, although not shown, is preferably filled to at least 95% or completely with the heat storage medium. The storage space 20 is bounded by an inner housing part 22 and an outer housing part 24 enclosing the inner housing part of the housing 18, wherein the inner or/and outer housing part 22 or 24 can in turn be implemented having one, two, or more parts and can analogously implement a storage space housing 22, 24.
[0043] An extraction device 26 for extracting heat out of the heat storage medium is disposed above the storage space 20 in the height direction 4 and outside of the at least one inner housing part 22. The extraction device 26 comprises a first solid body arrangement 28, a second solid body arrangement 30, and a third solid body arrangement 32, all described in greater detail below.
[0044] The first solid body arrangement 28 contacts the heat storage medium within the storage space 20. The first solid body arrangement 28 comprises a solid body 34 at the outlet side for achieving the solid body contact with the second solid body arrangement 30 as described in more detail below. The outlet-side solid body 34 extends substantially in the width and length directions 8 through 14 and the side thereof facing downward in the height direction 6 is disposed on the side of the inner housing part 22 facing upward, or optionally that of the outer housing part 24. The first solid body arrangement 28 further comprises further solid bodies, namely a plurality of struts 36 protruding downward in the height direction 6 into the storage space 20 for contacting the storage medium within the storage space 20. The ends of the struts 36 facing upward in the height direction 4 are directly connected to the outlet-side solid body 34 of the first solid body arrangement 28, while the end of the strut 36 facing downward in the height direction 6 is spaced apart from the inner housing part 22. In order to reach into the storage space 20 from the outlet-side solid body 34, the struts 36 extend through corresponding openings 38 in the inner housing part 22.
[0045] As can be seen in
[0046] The outlet-side solid body 34 comprises a surface 44 on the side thereof facing away from the struts 36 and substantially facing in the height direction 4, said surface serving for establishing solid body contact between the first and second solid body arrangements 28, 30 as described in more detail below. As is evident particularly from
[0047] The second solid body arrangement 30 is substantially implemented by a solid body 54 extending in the height direction 4 above the outlet-side solid body 34 of the first solid body arrangement 28 and spaced apart from the same, and extends substantially in the width and length direction 8 through 14 in order to be disposed flush with the outlet side solid body 34 of the first solid body arrangement 28 in the height direction 4, 6. On the side thereof facing toward the outlet-side solid body 34 in the height direction 6, the outlet-side solid body 54 in turn comprises a surface 56 by means of which the solid body contact with the first solid body arrangement 28 is to be established as described below in greater detail. The solid body 54 can thus also be referred to as an inlet-side solid body. The surface 56 of the second solid body arrangement 30 is also shaped in the manner of the lateral surface of a pyramid, optionally of a frustrum of a pyramid, wherein the pyramid or frustrum of a pyramid in the present case also comprises four sides, so that the surface 56 is analogously divided into four second surface segments 58 to 64.
[0048] The solid body 34 of the first solid body arrangement 28 and the outlet-side solid body 54 of the second solid body arrangement 30 are disposed fixed and non-displaceable relative to each other, such that the first surface segment 46 and the second surface segment 58, the first surface segment 48 and the second surface segment 60, the first surface segment 50 and the second surface segment 62, and the first surface segment 52 and the second surface segment 64 are opposite each other in the height direction 4, 6, and are thus associated with each other and furthermore inclined relative to each other, wherein the first and second surface segments associated with each other each preferably enclose an angle α of less than 60° or less than 10°.
[0049] On the side of the solid body 54 of the second solid body arrangement 30 facing away from the first solid body arrangement 28, said solid body has a side implementing an inner side 66 of a fluid container not shown in further detail, or a fluid line not shown in further detail, for heating a fluid, so that the heat extracted from the heat storage medium within the storage space 20 by means of the extraction device 26 can be dissipated to the fluid of a consumer at the inner side 66. The solid body 54 can therefore also be referred to as the outlet-side solid body 54. The inner side 66 is preferably the inner side 66 of the boiler of an evaporator for evaporating the fluid or for heating and optionally feeding the fluid to a turbine driven by the vapor.
[0050] The solid bodies 34, 54 of the first and second solid body arrangements 28, 30, particularly the surfaces 44, 56 thereof, are disposed in a contact space 68 implemented above the storage space 20 and within the housing 18. The contact space 68 is bounded in the height direction 4 and in the width and length direction 8 through 14 by an upper housing part 70 of the housing 18 and in the height direction 6 substantially by the outer housing part 24, optionally also by the inner housing part 22, wherein the contact space 68 is closed off, so that said space is not integrated in an air or fluid circuit or the like. The contact space 68 is further evacuated in order to prevent heat loss at the outlet-side solid body 34 of the first solid body arrangement 28 due to convention at the surface 44.
[0051] In order to be able to modify a heat flow from the first solid body arrangement 28, that is, starting from the heat storage medium within the storage space 20 via the struts 36 and the outlet-side solid body 24, to the second solid body arrangement 30, that is, to the solid body 54 and finally 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 modified by increasing or decreasing said heat flow from the first solid body arrangement 28 to the second solid body arrangement 30. In the concrete embodiment according to
[0052] As previously indicated, for the embodiment of the heat storage system 2 shown, a third solid body arrangement 32 is provided for modifying a solid body contact between the first solid body arrangement 28 and the second solid body arrangement 30 in an incremental or stepwise manner by increasing or decreasing a heat flow from the first solid body arrangement 28 to the second solid body arrangement 30. The third solid body arrangement 32 comprises a plurality of displaceable solid bodies, wherein four solid bodies 72 to 78 are provided in the embodiment shown. The third solid body arrangement 32 or at least the displaceable solid bodies thereof 72 to 78 are thereby disposed within the previously described contact space 68. While the first solid body arrangement 28 and the second solid body arrangement 30, particularly the solid bodies thereof 34 and 54, are disposed fixed relative to each other on the housing 18 and the surfaces thereof 44 and 56 are permanent spaced apart from each other, the displaceable solid bodies 72 through 78 are displaceable relative to the first and second solid body arrangement 28, 30, particularly relative to the two solid bodies 34 and 54. More precisely, the displaceable solid bodies 72 through 78 are displaceable transverse to the height axis 16 relative to the solid bodies 34, 54 and thereby translationally displaceable or slideable, wherein a drive device, not shown in further detail, for displacing the displaceable solid bodies 72 through 78 is associated with the same. The drive device preferably comprises an electric motor or hydraulic drive. The displaceable solid bodies 72 through 78 are also each wedge-shaped or wedge-like in design, so that said bodies have a surface facing downward in the height direction 6 and a surface facing upward in the height direction 4 inclined relative to each other due to the wedge shape, wherein the angle of inclination preferably corresponds to the previously described angle α between the first and second surface segments 46 through 52 and 58 through 64 associated with each other.
[0053] Thus the displaceable solid body 72 can be displaced in the width direction 8, starting from the first position thereof shown in
[0054] Although the embodiment shown in the figures, wherein the solid body contact is or can be established indirectly by means of the third solid body arrangement 32, is considered to be particularly advantageous, it is further noted that embodiments deviating therefrom can also be advantageous. It is noted, for example, that the heat storage system 2 can also be implemented such that the solid body contact between the first solid body arrangement 28 and the second solid body arrangement 30 can be modified continuously. The solid body contact between the first solid body arrangement 28 and the second solid body arrangement 30 could also be established directly, in that, for example, the solid bodies 34 and 54 are displaceable relative to each other for establishing or modifying a solid body contact. In this case, a displaceable solid body 54 of the second solid body arrangement 30 would be preferred, while the first solid body arrangement 28 retains the relative position thereof with respect to the storage space 20. In this case as well, the surfaces 44 and 56 facing each other must or should be adapted to the present special embodiment. Thus a corresponding displacement of the solid bodies 34 and 54 relative to each other can modify the solid body contact by modifying the size of a contact surface between the first solid body arrangement 28 and the second solid body arrangement 30.
[0055] 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. The heating device 80 thus particularly comprises a plurality of inductively heated heating struts 82 extending into the storage space 20 and extending substantially in the height directions 4, 6. In concrete terms, the heating struts 82 extend in the height direction 4 into the storage space 20 on one side through an opening 84 at the floor of the housing parts 22, 24, without the ends thereof facing upward in the height direction 4 adjoining the inner housing part 22; rather, the ends of the heating struts 82 are spaced apart from the inner housing part 22, so that the ends can also be referred to as free ends. In the opposite height direction 6, the heating struts 82 extend through said opening 84 into an induction space 86, wherein said induction space is a closed or/and evacuated space in which not only the heating strut 82 but also the inductor 8 associated with the heating strut 82, for example an electrical coil, is disposed for heating the heating strut 82 by means of a high-frequency alternating current.
[0056] In order to achieve the greatest possible contact surface area between the heating device 80 and the heat storage medium within the storage space 20, the ribs or fins 40 previously described with reference to the struts 36 of the first solid body arrangement 28 are provided on the heating struts 82 as well, and are disposed on the heating struts 82 and implemented by a multiply curved, elongated element 42, so that in this respect the depiction in
[0057] The closed or/and evacuated induction spaces 86 are substantially bounded by a lower housing part 90 of the housing 18 and in the height direction 4 by the inner or/and outer housing part 22, 24. Together with the top housing part 70, the bottom housing part 90 in which the inner housing part 22 and the outer housing part 24 are received forms the outer shell of the heat storage system 2.
[0058] As previously described, the first solid body arrangement 28, the second solid body arrangement 30, and the third solid body arrangement 32 are implemented by one or more solid bodies, wherein said solid bodies are preferably made of a metal or a metal alloy in order to ensure high thermal conductivity on the part of said solid body arrangements 28, 30, 32. Thus particularly the outlet-side solid body 34, the struts 36, and the ribs or fins 40 of the first solid body arrangement 28, the solid body 54 of the second solid body arrangement 30, and the displaceable solid bodies 72, 74, 76, 78 of the third solid body arrangement 32 are made of a metal or a metal alloy in the embodiment shown, wherein the same applies correspondingly to the heating struts 82 and the ribs or fins 40 disposed thereon. Particularly for the struts 36 or/and the heating struts 82, manufacturing from steel is possible, so that both good thermal conductivity and chemical resistance to the heat storage medium within the storage space 20 are provided. For the displaceable solid bodies 72, 74, 76, 78, a nonferrous metal, preferably copper or a copper alloy, is proposed as a material, whereas the solid bodies 34 or/and 54 could be made of steel or also of a nonferrous metal such as copper or a copper alloy.
[0059] While the metal solid bodies of the solid body arrangements 28, 30, 32 have particularly high thermal conductivity, at least the outer housing part 24 in which the inner housing part 22 having the storage space 20 is received, comprises a material having a significantly lower thermal conductivity than the material of said solid body arrangements 28, 30, 32. The same can apply fundamentally to the inner housing part 22 directly facing the storage space 20, but the inner housing part 22 can also be designed primarily such that a certain resistance of the housing relative to the heat storage medium within the storage space 20 is achieved, so that the inner housing part 22 can also fundamentally be made of steel.
[0060] From the depiction in
[0061] It must be noted in conclusion that the heat storage system 2 is preferably implemented as a latent heat storage system having what is known as a phase change material as the heat storage medium. The heat storage medium is preferably a salt or a salt mixture, wherein the heat output to the first solid body arrangement 28 preferably takes place by means of a transition of a liquid state into a solid state of the salt or salt mixture, for which reason a molten salt storage system can also be referred to here.
REFERENCE LIST
[0062] 2 Heat storage system [0063] 4 Height direction [0064] 6 Height direction [0065] 8 Width direction [0066] 10 Width direction [0067] 12 Length direction [0068] 14 Length direction [0069] 16 Height axis [0070] 18 Housing [0071] 20 Storage space [0072] 22 Inner housing part [0073] 24 Outer housing part [0074] 26 Extraction device [0075] 28 First solid body arrangement [0076] 30 Second solid body arrangement [0077] 32 Third solid body arrangement [0078] 34 Solid body [0079] 36 Struts [0080] 38 Openings [0081] 40 Ribs/fins [0082] 42 Element [0083] 44 Surface [0084] 46 First surface segment [0085] 48 First surface segment [0086] 50 First surface segment [0087] 52 First surface segment [0088] 54 Solid body [0089] 56 Surface [0090] 58 Second surface segment [0091] 60 Second surface segment [0092] 62 Second surface segment [0093] 64 Second surface segment [0094] 66 Inner side [0095] 68 Contact space [0096] 70 Top housing part [0097] 72 Displaceable solid body [0098] 74 Displaceable solid body [0099] 76 Displaceable solid body [0100] 78 Displaceable solid body [0101] 80 Heating device [0102] 82 Heating struts [0103] 84 Opening [0104] 86 Induction space [0105] 88 Inductor [0106] 90 Bottom housing part [0107] 92 Component [0108] α Angle