Metal Oxide Heat Storage Unit and Molding Method

Abstract

The present invention provides a metal oxide heat storage unit and a forming method, which can avoid the contact extrusion between adjacent metal oxide heat storage modules, ensure the reliability of the assembly structure at the same time, and reduce the generation of debris of the metal oxide modules. In the first aspect, a metal oxide heat storage unit is provided, which includes: a plurality of metal oxide heat storage modules; an elastic bonding layer formed between a plurality of adjacent metal oxide heat storage modules, which bonds and separates the adjacent metal oxide heat storage modules. In the second aspect, a forming method of a metal oxide heat storage unit is provided, including the following steps: applying a bonding material to the surface of the metal oxide heat storage module to form an elastic bonding layer with a specified thickness D. Align the porous structures of adjacent metal oxide heat storage modules, and assemble and combine the metal oxide heat storage modules. Heat and dry the metal oxide heat storage unit at 100-200 °C for 1-2 h to cure the elastic bonding layer.

Description

Technical Field

[0001] The present invention relates to the field of heat storage technology, and in particular to a metal oxide heat storage unit and a molding method. Background Art

[0002] Thermochemical heat storage technology is currently the heat storage technology with the highest heat storage density. It can achieve seasonal long-term storage and long-distance transportation, and has a high temperature range, which is suitable for large-scale power generation. Among them, the metal oxide thermochemical heat storage system mainly completes the energy storage and heat release cycle through the release and absorption of O2. This cycle process can be carried out in the atmospheric environment. Air serves as both a reactant and a heat transfer fluid, reducing the number of heat exchangers and auxiliary equipment for storing gases (such as carbon dioxide and steam). Its energy storage temperature can reach above 700°C. Within a small temperature change range, the energy storage density can reach 300-1000kJ / kg (including a small amount of sensible heat), which is 3-10 times the sensible heat in the corresponding temperature zone, making it very suitable for large-scale energy storage.

[0003] At present, the structures of metal oxide heat storage devices can be divided into three types: fixed bed type, fluidized bed type and moving bed type. Among them, the fixed bed type heat storage device is widely used due to its simple structure, the metal oxide heat storage module installed inside is not easy to wear, and the device manufacturing cost is low. Usually, a single metal oxide heat storage module is small, and multiple metal oxide heat storage modules need to be assembled into the required metal oxide heat storage unit of the appropriate size before being placed in the heat storage device. The existing assembly method is to engage the concave and convex structure on the surface of the metal oxide heat storage module.

[0004] However, the assembly structure with concave-convex structures is prone to displacement or collision during transportation, resulting in debris. In addition, during the reaction process, based on the reaction characteristics of the metal oxide thermochemical heat storage material itself, that is, during the cyclic heat storage / release process, the module undergoes redox reaction, the corresponding module mass increases / decreases, and the volume of the metal oxide heat storage module will also expand / contract to a certain extent. Adjacent metal oxide heat storage modules are prone to cracks due to extrusion, thus breaking. Summary of the invention

[0005] In view of the above problems, the present invention provides a metal oxide heat storage unit and a molding method, which can avoid collision or extrusion between adjacent metal oxide heat storage modules, ensure the reliability of the assembly structure, and reduce the generation of metal oxide module debris.

[0006] A first aspect of the present invention provides a metal oxide heat storage unit, which includes: a plurality of metal oxide heat storage modules; an elastic bonding layer, which is arranged between the plurality of metal oxide heat storage modules and is used to bond the plurality of metal oxide heat storage modules and absorb the expansion / contraction of the metal oxide heat storage modules.

[0007] According to this technical solution, multiple metal oxide heat storage modules can be simply and conveniently assembled together through an elastic bonding layer into a heat storage unit with the required size and shape, without manufacturing engaging shapes on the surface of the metal oxide heat storage modules, greatly reducing the preparation and assembly time of the metal oxide heat storage unit. Moreover, the bonding firmness of the elastic bonding layer is better than simple mechanical engagement, and it can also absorb and relieve the extrusion stress and thermal stress between adjacent heat storage modules through the elasticity of the elastic bonding layer, thereby improving the handling and installation reliability of the heat storage unit, ensuring the integrity of the heat storage module, and reducing the generation of debris.

[0008] As a preferred technical solution, the heat storage module is a porous module pressed from a metal oxide heat storage material. The porous structures of adjacent metal oxide heat storage modules are assembled in an aligned manner, and the elastic bonding layer is arranged between the metal oxide heat storage modules in a non-overlapping manner with the porous structure.

[0009] According to this technical solution, first of all, the metal oxide heat storage module has a very high energy storage temperature (>700 °C), as well as a large energy storage density, is suitable for large-scale energy storage, and has excellent chemical reaction reversibility and long-cycle life, which can ensure the safe and reliable long-term operation of the heat storage system;

[0010] Secondly, the porous structure of the metal oxide heat storage module can also enhance the convective heat transfer between the metal oxide heat storage material and air, as well as increase the reaction contact area between air and the material, increase the effective collisions between reaction molecules per unit volume, and is conducive to promoting the storage / discharge chemical reactions of the metal oxide heat storage material.

[0011] Finally, since the elastic bonding layer is arranged non-overlappingly with the porous structure, the porous structures of adjacent metal oxide heat storage modules can form a connected air channel, which can ensure the air circulation between adjacent metal oxide heat storage modules. Therefore, after the formed metal oxide heat storage unit is placed in the heat storage device, the temperature uniformity and heat transfer efficiency inside the heat storage device are good, improving the storage / discharge effect of the metal oxide heat storage unit.

[0012] As a preferred technical solution, the elastic bonding layer is formed into a porous elastic sheet with a specified thickness D. The maximum distance of unilateral expansion of the metal oxide heat storage module during the oxidation process is A. The specified thickness D is greater than 2A and less than 2A + 1 / 2A.

[0013] According to this technical solution, on the one hand, the porous structure of the elastic bonding layer can improve its buffering performance. The fluffy porous structure is more conducive to absorbing the expansion amount of the metal oxide heat storage module, and the elastic force generated during extrusion is smaller. On the other hand, the greater the volume difference between the shrinkage and expansion of the metal oxide heat storage module during the heat storage / discharge reaction (corresponding to the reduction / oxidation process), the greater the expansion distance A during the oxidation process, and thus a larger buffering space is required. When the thickness D of the elastic bonding layer is less than 2A, the elastic bonding layer cannot completely absorb the expansion distance of the metal oxide heat storage modules on both sides. When the elastic bonding layer is too thick, on the one hand, the gap between the metal oxide heat storage modules will increase, resulting in an increase in the volume of the entire metal oxide heat storage unit and a decrease in stability. On the other hand, the thermal expansion phenomenon of the too thick elastic bonding layer itself is also likely to cause a decrease in the connection stability between the metal oxide heat storage modules. When the specified thickness D is greater than 2A and less than 2A + 1 / 2A, the elastic bonding layer with the specified thickness D can better separate the metal oxide heat storage modules and at the same time provide a more reliable elastic buffer between adjacent metal oxide heat storage modules.

[0014] As a preferred technical solution, the elastic bonding layer at least includes a bonding material formed by compounding inorganic particles, inorganic fibers, an adhesive, and a pore-forming agent. The bonding material is applied to the edges of the adjacent surfaces of the metal oxide heat storage module. According to this technical solution, the composite material of inorganic particles and inorganic fibers has excellent elasticity and tensile strength and can maintain stable properties within the temperature range below 1500°C. The pore-forming agent can promote the formation of a porous elastic structure in the bonding material, further improving the expansion absorption amount of the elastic adhesive. Moreover, by applying the bonding material to the edges of the surface of the metal oxide heat storage module in a dot-like and line-like application method, the use of the bonding material can be reduced, and the cost can be reduced. At the same time, more surface area of the metal oxide heat storage module is left, increasing the contact area between the metal oxide heat storage module and air, which is beneficial to the progress of the heat storage / discharge reaction.

[0015] As a preferred technical solution, the elastic bonding layer further includes a gasket material formed by compounding the inorganic particles, the inorganic fibers, and the pore-forming agent. The bonding material is applied to the surface of the gasket material, and the maximum thickness of the elastic bonding layer formed by the combination of the gasket material and the bonding material is the specified thickness D.

[0016] According to this technical solution, through the combination of the bonding material and the gasket material, the bonding material only plays a bonding role, and the amount of the binder can be significantly reduced. Moreover, the filling of the gasket material can also buffer the thermal stress of adjacent modules. In addition, the gasket material can be prefabricated, which is more conducive to large-scale industrial production.

[0017] As a preferred technical solution, the metal oxide heat storage material of the metal oxide heat storage module is a manganese-based or copper-based metal oxide, and the value range of the specified thickness D is 1 mm - 1.25 mm.

[0018] According to this technical solution, the inventor took the manganese-based and copper-based metal oxide heat storage modules as examples for experimental determination and found that the maximum expansion distance of the manganese-based and copper-based metal oxide heat storage modules during the oxidation process is about 1 mm. On this basis, the preferred thickness range of the elastic bonding layer of the manganese-based and copper-based metal oxide heat storage modules was calculated, which can ensure the stability of the metal oxide heat storage unit while ensuring sufficient elastic margin.

[0019] As a preferred technical solution, the inorganic particles are one or a combination of boron nitride, zirconia, magnesia, titanium dioxide, and spinel-type oxides; the inorganic fibers are one or a combination of zirconia fibers, carbon fibers, and graphite fibers; the binder is one or a combination of titanium dioxide hydrosol, polyvinyl alcohol, and carboxymethyl cellulose; the pore-forming aid is zirconia hollow ceramic balls.

[0020] According to this technical solution, the inventor found through experiments that only 5% Si content, 0.5% Ca content, 0.1% Fe content, 0.25% Zn, 5% Al content, 10% Zn content, and any content of Ca element can greatly reduce the reaction performance of the copper-based or manganese-based metal oxide heat storage material. The reason is that the above elements will undergo phase reactions or chemical reactions with the main heat storage material (manganese-based or copper-based metal oxide), resulting in a decrease in the content of the main heat storage material, or causing agglomeration and sintering of the heat storage material. And the above materials will not undergo phase reactions or chemical reactions with the manganese-based or copper-based metal oxides even at high temperatures, can stably play a role in separating and bonding, and will not affect the heat storage performance of the main heat storage material.

[0021] As a preferred technical solution, the inorganic particles are zirconia and the inorganic fibers are zirconia fibers.

[0022] According to this technical solution, zirconia material as a separating material can maintain stable performance at high temperatures and does not react with the main heat storage material. In addition, the inorganic particles and inorganic fibers are selected from the same material, and the polymerizability during material compounding is good. Moreover, there is a strong interaction between the zirconia material and the manganese-based and copper-based metal oxides, which can grow adherently at high temperatures, improving the adhesion between the elastic bonding layer and the metal oxide heat storage module. In addition, the inventor's experiments found that the zirconia material can also stabilize the surface of the manganese-based / copper-based metal oxides at high temperatures, improving the anti-sintering performance of the copper-based / manganese-based metal oxides, which is beneficial to promoting the storage / discharge reaction and cycle life.

[0023] The second aspect of the present invention also provides a forming method for the metal oxide heat storage unit in any of the above technical solutions, including the following steps:

[0024] Step S1: Coat the surface of the metal oxide heat storage module with a bonding material to form an elastic bonding layer with a specified thickness D;

[0025] Step S2: Align the porous structures of adjacent metal oxide heat storage modules, and assemble and combine the metal oxide heat storage modules;

[0026] Step S3: Heat and dry the assembled metal oxide heat storage modules in Step S2 at 100 - 200 °C for 1 - 2 h to cure the elastic bonding layer.

[0027] As a preferred technical solution, Step S1 further includes the following sub-steps:

[0028] Step S11: Provide gasket material;

[0029] Step S12: Place the gasket material between adjacent metal oxide heat storage modules;

[0030] Step S13: Coat the surface of the metal oxide heat storage module with a bonding material to form an elastic bonding layer with a specified thickness D. Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of the side bonding of the metal oxide heat storage unit in the first embodiment of the present invention.

[0032] Figure 2 It is a schematic structural diagram of the upper and lower surface bonding of the metal oxide heat storage unit in the first embodiment of the present invention.

[0033] Figure 3 It is a schematic structural diagram of the side bonding of another metal oxide heat storage unit in the first embodiment of the present invention.

[0034] Figure 4 It is a schematic structural diagram of the upper and lower surface bonding of another metal oxide heat storage unit in the first embodiment of the present invention.

[0035] Figure 5 It is a flowchart of the forming method of the metal oxide heat storage unit in the first embodiment of the present invention.

[0036] Figure 6 It is a schematic structural diagram of the metal oxide heat storage unit prepared by the forming method of the metal oxide heat storage unit in the first embodiment of the present invention.

[0037] Figure 7 It is a schematic structural diagram of the cylindrical metal oxide heat storage unit in the first embodiment of the present invention.

[0038] Figure 8 This is a schematic structural view of the side bonding of the metal oxide heat storage unit in the second embodiment of the present invention.

[0039] Figure 9 This is a schematic structural view of the upper and lower surface bonding of the metal oxide heat storage unit in the second embodiment of the present invention.

[0040] Figure 10 This is another schematic structural view of the side bonding of the metal oxide heat storage modular forming unit in the second embodiment of the present invention.

[0041] Figure 11 This is another schematic structural view of the upper and lower surface bonding of the metal oxide heat storage modular forming unit in the second embodiment of the present invention.

[0042] Figure 12 This is a flowchart of the forming method of the metal oxide heat storage unit in the second embodiment of the present invention.

[0043] Reference numerals:

[0044] 100 - Metal oxide heat storage unit; 200 - Elastic bonding layer; 1 - Metal oxide heat storage module; 11 - Porous structure; 12 - Air channel; 2 - Bonding material; 3 - Gasket material; 4 - Through hole. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] First Embodiment

[0047] Figure 1 And Figure 2 This is a schematic structural view of a metal oxide heat storage unit provided by the first embodiment of the present invention. As Figure 1 shown, the metal oxide heat storage unit 100 includes: a plurality of metal oxide heat storage modules 1 and an elastic bonding layer 200 disposed between the plurality of metal oxide heat storage modules 1.

[0048] Among them, multiple metal oxide heat storage modules 1 are pressed from a metal oxide heat storage material formed by combining one or more of cobalt-based / manganese-based / copper-based / iron-based with excellent reaction performance and having a porous structure 11. The composite metal oxide heat storage material has a relatively high energy storage temperature (>700 °C), as well as a relatively large energy storage density, is suitable for large-scale energy storage, and has excellent chemical reaction reversibility and long-cycle life, which can ensure the safe and reliable long-term operation of the heat storage system. In addition, the porous structure 11 of the metal oxide heat storage module 1 can enhance the convective heat transfer between the metal oxide heat storage material and air, as well as increase the chemical contact area between air and the material, increase the effective collisions between reaction molecules per unit volume, and is conducive to the storage / discharge chemical reactions of the heat storage material.

[0049] It should be noted that in the drawings, the case where the metal oxide heat storage module 1 is formed into a cuboid is shown, which is more convenient for combined assembly and transportation stacking. However, the present invention is not limited thereto, and the case where the metal oxide heat storage module 1 is formed into other shapes also belongs to the protection scope of the present invention.

[0050] Among them, preferably, the porous structures 11 of adjacent metal oxide heat storage modules 1 correspondingly form a connected air channel 12. By aligning the porous structures 11 of adjacent metal oxide heat storage modules 1 to form an air channel 12, the air flow between adjacent metal oxide heat storage modules 1 can be ensured, so that after the formed metal oxide heat storage unit 100 is placed in the heat storage device, the temperature uniformity and heat transfer efficiency inside the heat storage device are good, and the storage / discharge effect is improved.

[0051] The elastic bonding layer 200 is disposed between multiple metal oxide heat storage modules 1 for bonding multiple metal oxide heat storage modules 1 and absorbing the expansion / contraction amount of the metal oxide heat storage modules 1. Specifically, the elastic bonding layer 200 is respectively bonded to the surfaces of two adjacent metal oxide heat storage modules 1 to form an elastic buffer zone between the two surfaces. Thus, when extrusion or collision occurs between the metal oxide modules, the elastic bonding layer 200 can absorb and relieve the extrusion stress between adjacent heat storage modules and the thermal stress during the reaction of the metal oxide heat storage material, ensure the integrity of the metal oxide heat storage module 1, and reduce the generation of debris. Preferably, the elastic bonding layer 200 is disposed in a manner that does not overlap with the porous structure 11 to ensure the air flow between adjacent metal oxide heat storage modules 1.

[0052] In addition, in this embodiment, the material and thickness of the elastic bonding layer 200 are not limited, and those skilled in the art can select them according to actual needs. In some preferred embodiments, the elastic bonding layer 200 is a porous elastic sheet with a specified thickness D. The porosity of the elastic bonding layer 200 can improve its buffering performance. The fluffy small holes are more conducive to absorbing the expansion amount of the metal oxide heat storage module 1, and the elastic force generated during extrusion is smaller. Further preferably, the maximum distance of unilateral expansion of the metal oxide heat storage module 1 during the oxidation process is A, the specified thickness D is greater than 2A, and the specified thickness D is less than 2A + 1 / 2A. The greater the volume difference between the shrinkage and expansion of the metal oxide heat storage module 1 during the heat storage / discharge reaction (corresponding to the reduction / oxidation process), the greater the expansion distance A during the oxidation process, and thus a larger buffer space is required. When the thickness D of the elastic bonding layer 200 is less than 2A, the elastic bonding layer 200 cannot completely absorb the expansion distance of the metal oxide heat storage modules 1 on both sides. When the elastic bonding layer 200 is too thick, on the one hand, the gap between the metal oxide heat storage modules 1 will increase, resulting in an increase in the volume of the entire metal oxide heat storage unit 100 and a decrease in stability. On the other hand, the thermal expansion phenomenon of the too thick elastic bonding layer 200 itself is also likely to cause a decrease in the connection stability between the metal oxide heat storage modules 1. When the specified thickness D is greater than 2A and less than 2A + 1 / 2A, the elastic bonding layer with the specified thickness D can better separate the metal oxide heat storage modules 1 and at the same time provide a more reliable elastic buffer between adjacent metal oxide heat storage modules 1.

[0053] As a preferred embodiment, the elastic bonding layer 200 can be a bonding material 2 coated on the surface of the porous metal oxide heat storage module 1 with a specified thickness D. The bonding material 2 at least includes inorganic fibers, inorganic particles, and an adhesive.

[0054] Among them, the inorganic fibers can be selected from one or a combination of silica fibers, alumina fibers, zirconia fibers, mullite fibers, magnesium silicate fibers, calcium silicate fibers, asbestos fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, etc.; the inorganic particles can be selected from one or a combination of silicon carbide, silicon nitride, boron nitride, alumina, zirconia, magnesium oxide, silica, titanium dioxide, spinel-type oxides, diatomite, cordierite, calcium silicate, magnesium silicate, etc.; the binder can be selected from one or a combination of silica aerogel, alumina sol, titanium dioxide hydrosol, sodium silicate sol, polyvinyl alcohol, carboxymethyl cellulose, etc. The layered structure formed by the composite of one-dimensional materials (inorganic particles) and two-dimensional materials (inorganic fibers) can have better tensile strength and elasticity, so as to enhance the bonding firmness between the metal oxide heat storage modules 1 while enhancing the buffering effect on the stress between the metal oxides. Moreover, the composite material formed by the above inorganic particles and inorganic fibers can remain stable below 1500°C, thus ensuring effective bonding of the modules and buffering of thermal stress during the heat storage / discharge process of the metal oxide heat storage module 1, and further preventing the bonding material 2 from failing under high-temperature conditions.

[0055] Further preferably, the bonding material 2 further includes a pore-forming agent, such as one or a combination of hollow oxide ceramics such as alumina hollow spheres, hollow glass microspheres, and mullite hollow spheres. The addition of the pore-forming agent can improve the elasticity of the bonding material 2, thereby enhancing the absorption and mitigation effect of the bonding material 2 on the stress between the metal oxide heat storage modules 1.

[0056] Figure 3 and Figure 4 Figure is a schematic structural diagram of another metal oxide heat storage unit provided by the first embodiment of the present invention. As Figure 3 and Figure 4 shown, the bonding material 2 is applied in a dot or line shape on the edge of the surface of adjacent metal oxide heat storage modules 1. By applying the bonding material 2 in a dot and line shape, the use of the bonding material 2 can be reduced, and the cost can be reduced; at the same time, more surface area of the metal oxide heat storage module 1 is left, increasing the contact area between the metal oxide heat storage module 1 and air, which is beneficial to the progress of the heat storage / discharge reaction.

[0057] This embodiment also provides a forming method for a metal oxide heat storage unit 100. Figure 5 Figure is a flowchart of the forming method for the metal oxide heat storage unit provided by the first embodiment of the present invention. As Figure 5 shown, the forming method for the metal oxide heat storage unit 100 provided by this embodiment includes the following steps:

[0058] Step S1: Apply a bonding material to the surface of the metal oxide heat storage module to form an elastic bonding layer with a specified thickness D.

[0059] Step S2: Align the porous structures of adjacent metal oxide heat storage modules, and assemble and combine the metal oxide heat storage modules.

[0060] Step S3: Heat and dry the assembled metal oxide heat storage modules in step S2 at 100 - 200 °C for 1 - 2 h to cure the elastic bonding layer.

[0061] Figure 6 The figure shows the overall structure diagram of the metal oxide heat storage unit 100 prepared by using the forming method of the metal oxide heat storage unit 100 provided in this embodiment. As Figure 6 shown, in the metal oxide heat storage unit 100 of this embodiment, at least on the sides of two adjacent metal oxide heat storage modules 1, a bonding material is coated, or alternatively, a bonding material can also be coated on all surfaces of the metal oxide heat storage module 1. The coating method of the bonding material can be surface coating, dot coating, line coating, or a combination of multiple coating methods, which is not limited herein. The bonding structure of the metal oxide heat storage unit 100 in this embodiment is firm, and has an elastic bonding layer 200 as a stress relaxation zone, so as to effectively reduce the fragmentation of the metal oxide heat storage module 1 during transportation or reaction.

[0062] In a preferred embodiment of the present invention, after step S3, the user can also cut the dried metal oxide heat storage unit 100 into various shapes according to requirements to adapt to the heat storage device (such as Figure 7 the columnar shape shown), and the user can consider the size and shape of the heat storage unit according to the energy storage device in the required application scenario, which is not limited herein. The modular installation and arbitrarily adjustable size of the metal oxide heat storage unit 100 enable the thermochemical heat storage / heat release technology to be suitable for large-scale applications in multiple scenarios efficiently.

[0063] Second Embodiment

[0064] The second embodiment of the present invention also provides a metal oxide heat storage unit and a forming method. Please refer to Figure 8 、 Figure 9 shown, the structure of the metal oxide heat storage unit 100 in the second embodiment of the present invention is basically the same as that in the first embodiment. The difference is that in this embodiment, the elastic bonding layer 200 is a combined structure of a bonding material 2 and a gasket material 3.

[0065] Among them, the gasket material 3 is arranged between adjacent metal oxide heat storage modules 1, and the bonding material 2 is coated on the surface of the gasket material 3. The surfaces of two adjacent metal oxide heat storage modules 1 can be bonded to the gasket material 3, so as to realize the assembly of the metal oxide heat storage module 1. The composition of the gasket material 3 is similar to that of the bonding material 2, and it is a composite material containing inorganic fibers and inorganic particles. Among them, the inorganic fibers can be selected from one or a combination of silica fibers, alumina fibers, zirconia fibers, mullite fibers, aluminosilicate fibers, magnesium silicate fibers, calcium silicate fibers, asbestos fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, etc.; the inorganic particles can be selected from one or a combination of silicon carbide, silicon nitride, boron nitride, alumina, zirconia, magnesium oxide, silica, titanium dioxide, spinel-type oxides, diatomaceous earth, cordierite, calcium silicate, magnesium silicate, etc. After adding the gasket material 3, the elastic requirement for the bonding material 2 can be reduced, and the amount of the binder can be reduced. In addition, the gasket material 3 can be preformed, with a more stable thickness and more conducive to large-scale industrial production.

[0066] Figure 10 and Figure 11 The combined structure between a preferred bonding material 2 and the gasket material 3 in the second embodiment is shown in Figure 10 and Figure 11 As shown, the bonding material 2 is coated on the edge of the gasket material 3 in a dot or line shape, and the maximum thickness of the elastic bonding layer 200 formed by the combination of the gasket material 3 and the bonding material 2 is the specified thickness D. Coating the bonding material 2 only in a dot or line shape on the edge can further reduce the amount of the binder, and increase the contact between the metal oxide heat storage module 1 and the air, improving the heat storage performance of the metal oxide heat storage module 1.

[0067] Among them, preferably, a plurality of protrusions with the specified thickness D (not shown) are formed on the surface of the gasket material 3. The protrusions with the specified thickness D on the surface of the gasket material 3 can reduce the use of the inorganic gasket material, reduce the cost, while ensuring that more air circulates on the surface of the heat storage module, better performing convective heat transfer, and having more contact reactions with the metal oxide heat storage material.

[0068] Among them, preferably, the gasket material 3 can also be formed into a columnar structure with the specified thickness D and bonded to the four vertices on the surface of the metal oxide heat storage module 1. Directly using the columnar gasket material 3 with the specified thickness D can, while ensuring effective separation, further reduce the usage amount of the gasket material 3, and provide a larger space for contact with the air, which is more conducive to the contact reaction between the metal oxide heat storage material and the air.

[0069] The second embodiment of the present invention also provides a forming method for a metal oxide heat storage unit, as shown in Figure 12As shown, compared with the first embodiment, step S1 in the forming method of the metal oxide heat storage unit 100 provided in this embodiment further includes the following sub-steps:

[0070] Step S11, provide gasket material;

[0071] Step S12, place the gasket material between adjacent metal oxide heat storage modules;

[0072] Step S13, apply a bonding material to the surface of the metal oxide heat storage module to form an elastic bonding layer with a specified thickness D.

[0073] In this embodiment, the use of the prefabricated gasket material 3 and the bonding material 2 to form the elastic bonding layer 200 can reduce the amount of binder used and is more conducive to large-scale industrial production. Moreover, the gasket material 3 is easy to be preformed or cut, and can be cut into any shape according to the surface shape of the metal oxide heat storage module 1. Or, the gasket material 3 with any shape can be prefabricated according to requirements. And the gasket material 3 is not easy to flow or deform, can provide a more reliable elastic buffer, ensure the integrity of the heat storage module, and reduce the generation of debris.

[0074] Third Embodiment

[0075] The third embodiment of the present invention provides a manganese-based or copper-based metal oxide heat storage unit. The third embodiment of the present invention is basically the same as the structure of the metal oxide heat storage unit 100 in the first embodiment or the second embodiment. The difference is that in this embodiment, the metal oxide heat storage material of the metal oxide heat storage module 1 is a manganese-based or copper-based metal oxide.

[0076] 1. Thickness selection

[0077] The inventor experimentally measured the shrinkage / expansion distance of the manganese-based and copper-based metal oxide heat storage modules during the heat storage / discharge reaction (i.e., the reduction / oxidation process), and measured that the maximum expansion distance A of the manganese-based and copper-based metal oxide heat storage modules 1 during the oxidation process is around 1 mm. On this basis, through the formula:

[0078]

[0079] It is calculated that the value range of the specified thickness D is 1 mm - 1.25 mm. The elastic bonding layer 200 within this thickness range can completely absorb the expansion / shrinkage amount of the manganese-based and copper-based metal oxide heat storage modules 1 and basically will not affect the stability of the metal oxide heat storage unit 100.

[0080] 2. Material selection

[0081] The inventors also studied the influence of different material selections of the elastic bonding layer 200 on the heat storage performance of the manganese-based and copper-based metal oxide heat storage modules 1. According to the experimental results, for the copper-based metal oxide heat storage material, only 5% Si content; 0.5% Ca content; 0.1% Fe content; 0.25% Zn content can cause a great decline in the reaction performance of the material; for the manganese-based metal oxide heat storage material, only 5% Al content, 10% Zn content, and Ca element can cause a great decline in the reaction performance of the material. The reason may be that the above elements will react phase or chemically with the main heat storage material (manganese-based or copper-based metal oxide), resulting in a decrease in the content of the main heat storage material, or causing agglomeration and sintering of the heat storage material. Therefore, for the metal oxide heat storage module 1 with a manganese-based or copper-based metal oxide heat storage material, materials with the above elements should be avoided.

[0082] Therefore, preferably, for the metal oxide heat storage module 1 made of a manganese-based or copper-based metal oxide heat storage material, the selection of the synthetic material of the elastic bonding layer 200 is as follows: the inorganic particles are one or more combinations of boron nitride, zirconia, magnesia, titanium dioxide, spinel-type oxides; the inorganic fibers are one or more combinations of zirconia fibers, carbon fibers, graphite fibers; the binder is one or more combinations of titanium dioxide hydrosol, polyvinyl alcohol, carboxymethyl cellulose, etc.; the pore-forming agent is zirconia hollow ceramic balls. Even at high temperatures, the above materials will not react phase or chemically with the manganese-based or copper-based metal oxide, enabling the elastic bonding layer 200 to stably play a role in separating and bonding, and at the same time will not affect the heat storage performance of the main heat storage material.

[0083] Further preferably, the inorganic particles are zirconia and the inorganic fibers are zirconia fibers. As a separating material, zirconia material can maintain stable performance at high temperatures, does not react with the main heat storage material, and the inorganic particles and inorganic fibers are selected from the same material, so the polymerizability during material compounding is good. In addition, there is a strong interaction between the zirconia material and the manganese-based and copper-based metal oxides, which can grow adherently at high temperatures, improving the adhesion between the elastic bonding layer 200 and the metal oxide heat storage module 1. In addition, through the experiments of the inventors, it is found that the zirconia material can also stabilize the surface of the manganese-based / copper-based metal oxide at high temperatures, improving the anti-sintering performance of the copper-based / manganese-based metal oxide, which is beneficial to promoting the storage / discharge reaction and cycle life.

[0084] In this embodiment, metal oxides of manganese-based and copper-based are used as common metal oxide heat storage materials with wide applications. The inventor studied the influence of elastic bonding layers 200 with different thicknesses and different materials on the heat storage performance of manganese-based and copper-based metal oxides, and provided a metal oxide heat storage unit 100 that can be widely applied, has good heat storage performance, and can avoid bumping or squeezing between adjacent metal oxide heat storage modules 1.

[0085] So far, the technical solution of the present invention has been described with reference to the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to the above specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A metal oxide heat storage unit, characterized in that, Comprising: Multiple metal oxide heat storage modules; An elastic bonding layer, disposed between the multiple metal oxide heat storage modules, for bonding the multiple metal oxide heat storage modules and absorbing the expansion / contraction amount of the metal oxide heat storage modules; The metal oxide heat storage module is a porous module pressed from a metal oxide heat storage material. The porous structures of adjacent metal oxide heat storage modules are assembled in an aligned manner, and the elastic bonding layer is disposed between the metal oxide heat storage modules in a manner that does not overlap with the porous structure; The elastic bonding layer is formed as a porous elastic sheet with a specified thickness D. The maximum distance of unilateral expansion of the metal oxide heat storage module during the oxidation process is A. The specified thickness D is greater than 2A and less than 2A + 1 / 2A.

2. The metal oxide heat storage unit according to claim 1, characterized in that, The elastic bonding layer at least includes a bonding material formed by compounding inorganic particles, inorganic fibers, an adhesive, and a pore-forming agent. The bonding material is coated on the edges of the adjacent surfaces of the metal oxide heat storage modules.

3. The metal oxide heat storage unit according to claim 2, characterized in that, The elastic bonding layer further includes a gasket material formed by compounding the inorganic particles, the inorganic fibers, and the pore-forming agent. The bonding material is coated on the surface of the gasket material. The maximum thickness of the elastic bonding layer formed by the combination of the gasket material and the bonding material is the specified thickness D.

4. The metal oxide heat storage unit according to claim 2 or 3, wherein the metal oxide heat storage material of the metal oxide heat storage module is a manganese-based or copper-based metal oxide, and the value range of the specified thickness D is 1 mm - 1.25 mm.

5. The metal oxide heat storage unit according to claim 4, characterized in that, The inorganic particles are one or more combinations of boron nitride, zirconia, magnesia, titanium dioxide, spinel-type oxides, etc.; the inorganic fibers are one or more combinations of zirconia fibers, carbon fibers, graphite fibers, etc.; the adhesive is one or more combinations of titanium dioxide hydrosol, polyvinyl alcohol, carboxymethyl cellulose, etc.; the pore-forming agent is zirconia hollow ceramic balls.

6. The metal oxide heat storage unit according to claim 5, characterized in that, The inorganic particles are zirconia, and the inorganic fibers are zirconia fibers.

7. A forming method of the metal oxide heat storage unit according to any one of claims 1-6, characterized in that, Including the following steps: Step S1: Coat the bonding material on the surface of the metal oxide heat storage module to form the elastic bonding layer with the specified thickness D; Step S2: Align the porous structures of adjacent metal oxide heat storage modules and assemble and combine the metal oxide heat storage modules; Step S3: Heat and dry the metal oxide heat storage modules assembled and combined in Step S2 at 100 - 200 °C for 1 - 2 h to cure the bonding material.

8. The forming method of the metal oxide heat storage unit according to claim 7, characterized in that, Step S1 further includes the following sub-steps: Step S11: Provide the gasket material; Step S12: Place the gasket material between adjacent metal oxide heat storage modules; Step S13: Coat the bonding material on the surface of the metal oxide heat storage module to form the elastic bonding layer with the specified thickness D.

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