Thermal storage enclosure, and corresponding set of thermal storage enclosure construction elements.

Abstract

Vertical thermal storage enclosure (1) comprising a thermally insulated cylindrical external wall (6) (9) fixed on a base (2) anchored to foundations (8), and closed by a cover (4), capable of being connected by sockets (3, 5) of a heat transfer gas to a renewable electricity production storage system, of the type comprising an internal part (7) consisting of several layers of a thermal storage material (10) extending horizontally and separated by metal grids (11, 19). The internal part (7) comprising a liner (21) not connected to the external wall (6), and whose grids (11, 19) are supported without fixed connection by nestable tubular segments (12), forms a floating structure. This enclosure (1) is modular, its elements (2, 4, 6, 11, 12, 19, 21) are manufactured in the factory and easily transportable in the form of a kit with simplified assembly without specific equipment or labor.

Description

Title of the invention: Thermal storage enclosure, and corresponding set of thermal storage enclosure construction elements. Technical field of the invention

[0001] The present invention relates to a thermal storage enclosure, and a corresponding set of storage enclosure construction elements. Technological background

[0002] Electricity storage represents a major challenge for the energy transition because it allows surplus renewable production to be stored and used when needed.

[0003] The reversible conversion of electricity into thermal form is an interesting solution for storing large quantities of energy. The advantage of this approach is that the energy density (storage capacity per unit of volume or mass) is high and that the storage capacity can be easily increased by increasing the mass of material used. Since the storage materials meeting the technical constraints of this technology are available in abundance, are inexpensive and are non-polluting, this principle is particularly suitable for high energy capacities or more efficient than other existing solutions (electrochemical batteries, flywheels, hydrogen, etc.).

[0004] Excess electricity is therefore converted into heat and is stored in a material in the form of an increase in its temperature. This energy is then released by lowering the average temperature of the materials. The supply and recovery of heat are achieved by the forced circulation of a gas (typically air) set in motion by a set of turbomachines (turbines, compressors) and which serves as a heat transfer fluid for heat exchanges.

[0005] The material is placed in enclosures to be thermally isolated from the environment. The storage materials that can be used are natural (for example basalt rocks) or industrially produced from mineral materials (for example ceramics or refractory materials). Inside each enclosure, the material is heated from above and cooled from below, further considering the natural stratification between the hot gas and the cold gas, this leads to the formation of a "thermal front", that is to say a transition zone between the "high" temperature at the top of the enclosure and the "low" temperature at the bottom of the enclosure. For the proper functioning of the process this front must be as narrow as possible and must remain as horizontal as possible. For this it is advantageous to have several separate layers of storage material, each separated from the next by an air gap to prevent the front from destabilizing.

[0006] A thermal electricity storage system is for example known from American patent US4405010. In this system, the thermal storage enclosure is monobloc and is in the form of a cylindrical housing comprising an inlet and an outlet for the circulation of an air flow. This housing is filled in particular with a refractory material forming layers separated for example by metal rods supported by the walls of the enclosure.

[0007] This single-block structure is simple; however, it is not suitable for enclosures with a high energy capacity because this would lead to having to design reinforced walls to resist the lateral and vertical forces exerted by the rods and the large volume of corresponding material.

[0008] The most favorable areas for the deployment of massive storage capacities are often isolated areas. Indeed, these areas often have a weak electricity network and depend on electricity mainly produced by fossil fuels (fuel oil in particular). The deployment of renewable production means therefore follows a logic of reducing energy dependence on fossil fuels, the energy bill and the carbon footprint of the electricity sector. However, the penetration of decarbonized energies is limited because it is necessary to ensure the supply of electricity regardless of the weather conditions. These areas are therefore favorable to the development of storage as a replacement for thermal production.

[0009] However, it can be problematic to transport installations comprising single-piece thermal storage enclosures of the type described in patent US4405010 to isolated locations, as they can be difficult to access.

[0010] In order to overcome these drawbacks, there is therefore a first need for a thermal storage enclosure having a lightweight and optimized structure to facilitate its transport.

[0011] In addition, it may be difficult to find specific equipment or labor in these isolated locations if the assembly is complex. There is therefore also a second need for a set of specific storage enclosure construction elements to simplify the construction and assembly thereof. Presentation of the invention

[0012] The aim of the present invention is therefore to satisfy these needs by producing a thermal storage enclosure of the type extending substantially vertically and having an external part comprising a lower part provided with at least a first inlet for a heat transfer fluid, an upper part provided with at least one second intake of this fluid and an intermediate part of substantially cylindrical shape enveloping an internal part comprising one or more substantially horizontal layers of a thermal storage material supported by separation means extending substantially horizontally.

[0013] According to the invention, this internal part remarkably forms a floating structure.

[0014] The separation means are formed, according to the invention, of one or more openwork plates supported by at least three vertical supports resting on foundations external to the external part.

[0015] The lower part of the thermal storage enclosure also advantageously rests on these foundations.

[0016] According to the invention, the plates and the supports are advantageously provided respectively with first and second complementary inclined surfaces in contact.

[0017] According to the invention again, the supports are very advantageously made up of one or more segments of a tubular element each having a lower end with an external dimension substantially smaller than an internal dimension of said tubular element.

[0018] Preferably, the second surfaces are formed of collars arranged at an upper end of each of the segments having a radial section inclined at an angle of between 0° and 45° relative to a horizontal plane.

[0019] In the thermal storage enclosure according to the invention, the supports are regularly distributed in tangential and radial directions of a cross-section of the floating structure and, remarkably, a vertical projection of the plates forms a paving of the cross-section between traces of these supports.

[0020] According to the invention, each of the plates adjacent to the intermediate part is advantageously provided with a peripheral fin facing this intermediate part cooperating internally with a lower edge of a cylindrical envelope surrounding each of the layers of the thermal storage material.

[0021] Preferably, the external part is coated internally with a thermal insulator in contact with this envelope.

[0022] In order to satisfy the second need more particularly, benefit will be gained from a set of construction elements for thermal storage enclosures according to the invention, comprising:

[0023] - first metal tubes having a first flared end and a second reduced end, this second end being intended to fit into the first end;

[0024] - a metal base substantially in the shape of a hemisphere comprising seconds through metal tubes each having on a concave side of this hemisphere a third end capable of receiving the second end of a copy of the first tubes and on a side opposite the concave side, a fourth end having a flange capable of being fixed to an anchor, and further comprising a first opening capable of being connected to a thermal storage system;

[0025] - a substantially hemispherical metal cover comprising a second opening suitable for connection to this thermal storage system;

[0026] - one or more metal cylinder elements intended to form a wall exterior of these enclosures;

[0027] - first metal grid elements each comprising first legs intended to cooperate with the first end of each of the first tubes;

[0028] - second metal grid elements each comprising second legs intended to cooperate with the first end of each of the first tubes and each further comprising in part a peripheral rim;

[0029] - metal liner elements each intended to cooperate with this rim peripheral;

[0030] - a heat storage material;

[0031] - a thermal insulation material intended to internally cover the base, the cover and the wall of the enclosures.

[0032] These few essential specifications will have made obvious to the person skilled in the art the advantages provided by the thermal storage enclosure, and the set of corresponding storage enclosure construction elements, described above in relation to the prior art, in terms of ease of transport, construction and assembly.

[0033] The detailed specifications of the invention are given in the following description in conjunction with the attached drawings.

[0034] It should be noted that these drawings have no other purpose than to illustrate the text of the description and do not constitute in any way a limitation of the scope of the invention. Brief description of the figures

[0035] [Fig-1] is an axial section of the thermal storage enclosure according to the invention.

[0036] [Fig.2] is a detailed view of zone A of the thermal storage enclosure according to the invention shown in [Fig.l].

[0037] [Fig.3] is a detailed view of zone B of the thermal storage enclosure according to the invention shown in [Fig.l].

[0038] [Fig.4] is a detailed view of zone C of the thermal storage enclosure according to the invention shown in [Fig.l].

[0039] [Fig.5] is a detailed view of zone D of the thermal storage enclosure according to the invention shown in [Fig.l].

[0040] [Fig.6] is a detailed view of zone E of the thermal storage enclosure according to the invention shown in [Fig.l].

[0041] [Fig.7] is a cross-section along FF of the thermal storage enclosure according to the invention shown in [Fig.l].

[0042] [Fig.8] schematically represents a first phase of an assembly of the thermal storage enclosure according to the invention.

[0043] [Fig.9] schematically represents a second phase of an assembly of the thermal storage enclosure according to the invention.

[0044] [Fig. 10] schematically represents a third phase of an assembly of the thermal storage enclosure according to the invention.

[0045] [Fig. 11] schematically represents a fourth phase of an assembly of the thermal storage enclosure according to the invention. Description of the embodiments

[0046] The thermal storage enclosure 1 according to the invention, of the general shape of a cylinder extending substantially vertically, is shown in [Fig.l] in axial section.

[0047] We distinguish the external part comprising:

[0048] - the lower part 2, provided with the first socket 3 of the heat transfer fluid, of air preference:

[0049] - the upper part 4, provided with the second intake 5 of the heat transfer fluid;

[0050] - the intermediate part 6 of substantially cylindrical shape enveloping the part internal 7.

[0051] The lower part 2 of the enclosure 1 serves as a base and transfers the mechanical forces exerted by the internal part 7 onto the foundations 8. The first socket 3 is capable of being connected to a pipe of the thermal storage system.

[0052] The intermediate part 6 is preferably in a single piece, or, alternatively, made up of several assembled metal cylinder elements.

[0053] The upper part 4 serves as a cover and the second socket 5 is also capable of being connected to the pipeline of the thermal storage system.

[0054] The intermediate part 6 is assembled with the lower 2 and upper 4 parts by bolting.

[0055] The thermal insulator 9 is fixed inside the external part 2, 4, 6 in order to limit heat losses. Lightweight refractory insulators, such as those used in the steel, glass, industrial furnace industries, of the calcium silicate or ceramic fiber type, are suitable for this purpose.

[0056] These refractory insulators are in particular calcium silicate bricks joined using a refractory cement or else flexible and glued fibrous or microporous insulating materials.

[0057] The thermal storage enclosure 1 being a pressure tank, the external part 2, 4, 6 is made of steel, such as the P265GH alloy, standard in this use.

[0058] The thermal storage enclosures 1 according to the invention have dimensions determined according to the targeted energy capacity.

[0059] In the preferred embodiments of the invention, two enclosures 1, operating in a complementary manner, known per se, for a storage capacity in thermal form of the equivalent of approximately 4 MWh electric, have a volume of approximately 60 m3, a height of approximately 5 m and a diameter of approximately 4 m (i.e. a height / diameter ratio substantially equal to 1.25).

[0060] The internal part 7 preferably comprises around ten layers 10 of the thermal storage material such as alumina-rich refractory ceramics or natural materials of the basalt rock type.

[0061] These layers 10 are separated by the horizontal plates 11 supported by the vertical supports 12 resting on the foundations 8.

[0062] As clearly shown in the cross-section ([Fig. 1]) of the thermal storage enclosure 1 according to the invention, each of the vertical supports 12 is made up of segments of a tubular element.

[0063] The detailed view of zone A ([Fig.2]) shows that the lower end 13 of one of the segments 12 has a smaller section so as to fit into the upper end 14 of another of the segments 12.

[0064] This upper end 14 comprises a collar 15 inclined at 45° relative to the horizontal on which the horizontal plates 11 rest by means of the complementary inclined surfaces 16 with which they are provided.

[0065] Each of the segments 12 preferably has a height of between approximately 50 and 60 cm so as to limit the weight of storage material per layer 10 and to limit the necessary thickness of the horizontal plates. A maximum thickness of these plates is set at 10 mm (preferably 5 mm), because these dimensions are more widely available from suppliers of semi-finished steel products (sheets in the form of plates or coils), and also because it is possible to punch steel plates of this thickness.

[0066] The flared part 14 and the reduced part 13 of the segments 12 are produced by stamping operations or, alternatively, by cold forming of cylindrical tubes.

[0067] The detailed view of zone B ([Fig.3]) shows that the upper end 14 of each of the segments 12 supports a last layer 17 of storage material thermal (10) is closed by a plug 18 preventing the storage material from penetrating inside the tubes.

[0068] The copies 19 of the plates 11 adjacent to the intermediate part 6 of the external part of the enclosure 1 are provided with a peripheral fin 20 opposite the thermal insulation 9 and support the liner 21 as clearly shown in the detailed view of zone C ([Fig.4]).

[0069] The vertical supports 12 fit at their bases into other tubular segments 22 passing through a hemispherical part of the base 2 of the enclosure 1, as shown in the detailed view of zone D ([Fig.5]), so as to transfer all the vertical forces exerted by the internal part 7 onto the foundations 8, as shown in the detailed view of zone E ([Fig.6]).

[0070] It will be noted that these other tubular segments 22 are filled with the same thermal insulation 9 as that covering the interior of the entire external part 2, 4, 6 during the assembly operation.

[0071] The base 2 is fixed to the foundations 8 by an anchor on a metal support previously cast in the concrete, chemical anchors 23 or others.

[0072] Neither the plates 19 nor the liner 21 resting on them are fixed to the intermediate part 6, but simply in contact with the thermal insulation 9: in this way the structure formed by the internal part 7 is said to be "floating".

[0073] The horizontal plates 11, 19 supported by the vertical supports 12, which retain the storage material 10, 17 cover the cross-section of the enclosure 1 in a regular pattern (hexagonal, square, triangular shaped plates, etc.) or irregular as shown in [Fig.7].

[0074] Any other set of shapes covering the section of the enclosure 1 is optimized according to technical constraints such as: diameter of the enclosure 1, weight of the storage material 10, 17, material and thickness of the plates 11, 19, number of vertical supports 12.

[0075] The plates 11, 19 are placed next to each other on the vertical supports 12 and are held in place by means of the inclined supports 16 cooperating with the collars 15 and the weight of the storage material 10, 17 placed on them.

[0076] The shape of the plates 11, 19 and the position of the vertical supports 12 under these plates 11, 19 are designed so that the center of gravity of the plates 11, 19, alone or supporting the storage material 10, 17, is always contained in their respective support surface, without having recourse to a structural link between the plates 11, 19, or between the plates 19 and the intermediate part 6.

[0077] The plates 11, 19 preferably have a thickness of approximately 5 mm so as to withstand the mechanical and thermal stresses depending on the storage material 10 used and the alloy used for their manufacture, while remaining within types of semi-finished products that are widely available and easily processed in the factory. stockage 10 utilisé et de l’alliage utilisé pour leur fabrication, tout en restant dans des types de produits semi-finis largement disponibles et facilement travaillés en usine.

[0078] Regular perforation of the plates 11, 19 ensures the passage of air while preferentially retaining the storage material 10, 17, which is in granular and unstructured form. The size of the holes is taken to be equal to 80 - 90% of the minimum dimension of the grains of the storage material 10, 17, the diameter of which ranges from 10 to 30 mm. The surface density of the holes is taken to be equal to the porosity of the storage material 10, 17, within a few percent, so as to facilitate the passage of air.

[0079] The liner 21, a thin - walled metallic envelope (preferably less than 1 mm thick), protects the thermal insulator 9 from damage caused by contact with the storage material 10, 17 (deformation, crushing or piercing caused by the movement of the grains of the storage material 10, 17 generated by their expansion, if they were in direct contact with the thermal insulator 9).

[0080] The liner 21 also prevents the grains of the storage material 10, 17 from infiltrating into the space between the horizontal plates 19 and the thermal insulator 9 as shown well in the [Fig.4]. This liner 21 has no structural function (no vertical load bearing).

[0081] All of the parts constituting the thermal storage enclosure 1 according to the invention are manufactured off-site, in a factory, using simple processes: cutting, bending, stamping, cold forming, punching, and welding for the minimum number of parts. Precision or overly complex operations are not favored: forging, casting, molding, or machining. Thus, the manufacture of the parts is simplified and is therefore less expensive.

[0082] In addition, these parts are advantageously manufactured in large quantities in the factory from readily available standard semi-finished products (plates, tubes, bars) in order to achieve economies of scale, and are then transported and assembled on site, thus reducing the construction time of the thermal storage enclosure 1 on site.

[0083] With the same objective of simplifying and accelerating construction, the internal and external parts do not require complex assembly when constructing the thermal storage system installation.

[0084] The parts constituting the thermal storage enclosure 1 are easily handled with simple and widely available lifting means. In addition, these parts are mainly laid, fitted or screwed manually.

[0085] The internal 7 and external 2, 4, 6 parts are self-supporting and independent. Some connections are not rigid, which has the advantage of allowing these internal 7 and external 2, 4, 6 parts to expand with temperature variations.

[0086] Such a modular (prefabricated parts) and simplified (simple assembly) design makes for faster deployment of installations (early manufacturing and easy transport of complete kits), but also the deployment of these installations without specific equipment or labor, which is important in isolated areas, suitable for the implementation of electricity storage systems.

[0087] According to the invention, a complete kit necessary for assembling the thermal storage enclosure 1 described above, according to the procedure shown diagrammatically in Figures 8 to 11, comprises all of the following construction elements:

[0088] - the first 24 metal tubes in a number depending on the thermal capacity nominal of the enclosure 1, and having a first flared end 25 and a second reduced end 26, this second end 26 being intended to fit into the first end 25;

[0089] - the metal base 2 substantially in the shape of a hemisphere, of diameter function of the chosen enclosure model, comprising second metal tubes 22 passing through each having on a concave side of this hemisphere a third end 27 capable of receiving the second end 26 of a copy of the first tubes 24 and on a side opposite the concave side, a fourth end 28 having a flange capable of being fixed to an anchor 23, and further comprising a first opening 3 capable of being connected to a thermal storage system;

[0090] - the substantially hemispherical metal cover 4, with a diameter corresponding to that of the base 2, comprising a second opening 5 capable of being connected to this thermal storage system;

[0091] - the metal cylinder or cylinder elements intended to form the wall exterior 6 of the enclosure provided 1 by bolting on the base 2;

[0092] - the first metal grid elements 29, in a number corresponding to the nominal characteristics of the enclosure 1 provided, each comprising the first legs 30 intended to cooperate with the first end 25 of each of the first tubes 24, by simple installation during the first assembly phase, as shown in [Fig.8];

[0093] - the second metal grid elements, intended to be arranged opposite the outer wall 6 of the enclosure 1 provided, each comprising second legs capable of cooperating with the first end of each of the first tubes 24 and each further comprising in part a peripheral rim.

[0094] The kit includes all the construction elements to iterate in the second assembly phase, until completion of the assembly of the enclosure 1, the first assembly phase shown diagrammatically in [Fig.8]: installation of another level of first tubes 24 on the previous level of first tubes 24 and first 29 and second grid elements, as illustrated in [Fig.9].

[0095] The kit further comprises:

[0096] - metal liner elements each intended to cooperate with the rim peripheral of the second grid elements;

[0097] - a heat storage material 31 in sufficient volume to fill uniformly each level, while providing an air gap 32, by iterating the third and fourth phases of the procedure for assembling the enclosure 1 provided, shown diagrammatically respectively in Figures 10 and 11;

[0098] - a thermal insulation material intended to internally cover the base, the cover and the wall of the enclosure 1 provided, during an initial phase of the assembly.

[0099] In this way, this set of construction elements of a thermal storage enclosure 1 meets the needs of a lightweight and optimized structure to facilitate its transport, as well as a specific assembly to simplify the construction and assembly thereof.

[0100] As goes without saying, the invention is not limited to the preferred embodiments set out above.

[0101] The thermal capacity of the storage enclosure 1, its volume, its dimensions are indicative. The same applies to the dimensions of the elements of the storage enclosure 1 and the materials cited as examples.

[0102] The invention therefore embraces, on the contrary, all possible variant embodiments within the limits of the subject of the claims below.

Claims

Claims

1. Thermal storage enclosure (1) of the type extending substantially vertically and having an external part (2, 4, 6) comprising a lower part (2) provided with at least a first inlet (3) for a heat transfer fluid, an upper part (4) provided with at least a second inlet (5) for said fluid and an intermediate part (6) of substantially cylindrical shape enveloping an internal part (7) comprising one or more substantially horizontal layers of a thermal storage material (10) supported by separation means (11, 19) extending substantially horizontally, said internal part (7) forming a floating structure, characterized in that said separation means (11, 19) are formed of one or more perforated plates supported by at least three vertical supports (12) resting on foundations (8) external to said external part (2, 4, 6).

2. Thermal storage enclosure (1) according to the preceding claim 1, characterized in that said lower part (2) bears on said foundations (8).

3. Thermal storage enclosure (1) according to any one of the preceding claims 1 or 2, characterized in that said plates (11, 19) and said supports (12) are respectively provided with first (16) and second (15) complementary inclined surfaces in contact.

4. Thermal storage enclosure (1) according to any one of the preceding claims 1 to 3, characterized in that said supports (12) are made up of one or more segments of a tubular element each having a lower end (13) with an outer dimension substantially smaller than an inner dimension of said tubular element.

5. Thermal storage enclosure (1) according to the preceding claim 4, characterized in that said second surfaces (15) are formed of collars (15) arranged at an upper end (14) of each of said segments having a radial section inclined at an angle between 0° and 45° relative to a horizontal plane.

6. Thermal storage enclosure (1) according to any one of the preceding claims 1 to 5, characterized in that said supports (12) are regularly distributed in tangential and radial directions of a cross-section of said floating structure (7) and in that a vertical projection of said plates (11, 19) forms a paving of said cross-section between traces of said supports (12).

7. Thermal storage enclosure (1) according to any one of the preceding claims 1 to 6, characterized in that each of said plates (19) adjacent to said intermediate part (6) is provided with a peripheral fin (20) facing said intermediate part (6) cooperating internally with a lower edge of a cylindrical envelope (21) surrounding each of said layers (10).

8. Thermal storage enclosure (1) according to claim 7, characterized in that said external part (2, 4, 6) is internally coated with a thermal insulator (9) in contact with said casing (21).

9. Set of thermal storage enclosure construction elements (1) according to any one of the preceding claims 1 to 8, comprising: first metal tubes (24) having a first flared end (25) and a second reduced end (26), said second end (26) being intended to fit into said first end (25); a metal base (2) substantially in the shape of a hemisphere comprising second metal through tubes (22) each having on a concave side of said hemisphere a third end (27) capable of receiving said second end (26) of a copy of said first tubes (24) and, on a side opposite said concave side, a fourth end (28) having a flange capable of being fixed to an anchor (23), and further comprising a first opening (3) capable of being connected to a thermal storage system; a substantially hemispherical metal cover (4) comprising a second opening (5) capable of being connected to said thermal storage system; one or more metal cylinder elements intended to form an outer wall (6) of said enclosures (1); first metal grid elements (29) each comprising first legs (30) intended to cooperate with said first end (25) of each of said first tubes (24); second metal grid elements each comprising second legs intended to cooperate with said first end (25) of each of said first tubes (24) and each further comprising in part a peripheral rim (20); metal liner elements each intended to cooperate with said peripheral rim (20); a heat storage material (31); a thermal insulation material (9) intended to internally coat said base (2), said cover (4) and said wall (6).

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