Heat storage structure and heat storage device

Abstract

To provide a heat storage structure which can improve input / output performance of heat.SOLUTION: A heat storage structure includes a chemical thermal storage medium (10) which can reversibly perform a heat radiation caused by a binding reaction of a reaction medium and a heat storage caused by an elimination reaction of the reaction medium, and an accommodation part (20) having a porous wall (24) which partitions a space (21) accommodating the chemical thermal storage medium (10) and extends from a first end face (22) to a second end face (23). The porous wall (24) has two or more areas having porosities different from each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat storage structure and a heat storage device. [Background technology]

[0002] Heat storage technology has been attracting attention due to its efficient use of energy. Among heat storage technologies, chemical heat storage is a method of storing and releasing heat by utilizing the heat of reaction generated when a chemical heat storage material chemically reacts with a reaction medium, and by physically separating the chemical heat storage material from the reaction medium and preventing the chemical reaction from proceeding, it is possible to maintain the heat storage state for a long period of time. In addition, chemical heat storage has a higher heat storage density than other heat storage methods (such as latent heat storage), and is also advantageous in terms of miniaturization.

[0003] In a heat storage device (heat storage reactor) that uses chemical heat storage, during a heat release reaction (exothermic reaction), it is required to quickly supply a reaction medium to the chemical heat storage material and conduct the generated reaction heat to the outside. Also, during a heat storage reaction, it is required to quickly supply heat to the chemical heat storage material and release the desorbed reaction medium. In view of this, various heat storage devices have been proposed in which a chemical heat storage material is accommodated in a porous accommodation portion through which a reaction medium can flow. For example, Patent Document 1 proposes a heat storage device in which a chemical heat storage material is accommodated in a restraining member made of a porous material. Patent Document 2 also proposes a heat storage device in which at least a portion of the cells of a porous honeycomb structure is filled with a chemical heat storage material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-60177 [Patent Document 2] International Publication No. 2018 / 163676 Summary of the Invention [Problem to be solved by the invention]

[0005] In the heat dissipation reaction, from the viewpoint of quickly supplying the reaction medium to the chemical heat storage material, it is desirable to increase the porosity of the porous storage portion in order to increase the flow path of the reaction medium. On the other hand, from the viewpoint of quickly conducting the heat generated in the chemical heat storage material to the outside, it is desirable to reduce the porosity of the porous storage portion in order to improve the thermal conductivity of the porous storage portion. Similarly, in the heat storage reaction, from the viewpoint of quickly releasing the reaction medium desorbed from the chemical heat storage material, it is desirable to increase the porosity of the porous storage portion, while from the viewpoint of quickly conducting heat to the chemical heat storage material, it is desirable to reduce the porosity of the porous storage portion. Thus, in the porous storage portion, there is a trade-off relationship between the improvement of the supplyability and releaseability of the reaction medium and the improvement of the thermal conductivity.

[0006] The heat storage devices described in Patent Documents 1 and 2 have a uniform porosity in the porous storage portion, so there is a limit to the heat input / output performance. That is, in the heat storage devices described in Patent Documents 1 and 2, if the porosity of the porous storage portion is increased overall, a large amount of reaction medium can be supplied to the chemical heat storage material in the heat dissipation reaction, but the heat generated in the chemical heat storage material is difficult to conduct to the outside, so the desired heat output performance cannot be obtained. Also, in the heat storage reaction, although the reaction medium desorbed from the chemical heat storage material can be quickly removed, the heat is difficult to conduct to the chemical heat storage material, so the desired heat input performance cannot be obtained. On the other hand, if the porosity of the porous storage portion is reduced overall, the heat generated in the chemical heat storage material can be efficiently conducted from the porous storage portion to the outside in the heat dissipation reaction, but the supply of the reaction medium takes time, so the desired heat output performance cannot be obtained. Also, in the heat storage reaction, although heat can be efficiently supplied to the chemical heat storage material, the release of the reaction medium desorbed from the chemical heat storage material takes time, so the desired heat input performance cannot be obtained.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a heat storage structure and a heat storage device that are capable of improving the heat input / output performance. [Means for solving the problem]

[0008] As a result of intensive research into the storage section that stores the chemical thermal storage medium, the inventors have found that the above-mentioned problems can be solved by configuring a specific porous wall that forms the storage section to have two or more regions with different porosities, and have completed the present invention. That is, the present invention is exemplified as follows.

[0009] [1] A chemical heat storage material capable of reversibly releasing heat through a bonding reaction with a reaction medium and storing heat through a desorption reaction of the reaction medium; A storage section that defines a space for storing the chemical thermal storage material and has a porous wall extending from a first end surface to a second end surface; Equipped with The heat storage structure has two or more regions with different porosity in the porous wall.

[0010] [2] The heat storage structure according to [1], wherein the porous wall has at least an area A and an area B, and the ratio of the porosity of the area A to the porosity of the area B is 1.01 to 90.

[0011] [3] The heat storage structure according to [2], wherein the porous wall has the region A and the region B in a direction perpendicular to a contact surface between the chemical heat storage material and the porous wall.

[0012] [4] The heat storage structure according to [3], wherein the region A and the region B are layered.

[0013] [5] The heat storage structure according to any one of [2] to [4], wherein the region B is located on the contact surface side between the chemical heat storage material and the porous wall.

[0014] [6] The heat storage structure according to any one of [2] to [4], wherein the region A is located on the contact surface side between the chemical heat storage material and the porous wall.

[0015] [7] The heat storage structure according to [2], wherein the porous wall has the region A and the region B in a direction parallel to a contact surface between the chemical heat storage material and the porous wall.

[0016] [8] The heat storage structure according to any one of [2] to [7], wherein the porosity of the region A is 30 to 90%.

[0017] [9] The heat storage structure according to any one of [2] to [8], wherein the porosity of the region B is 1 to 60%.

[0018]

[10] The heat storage structure according to any one of [1] to [9], wherein the pore size of the porous wall at the contact surface with the chemical heat storage material is smaller than the particle size of the chemical heat storage material.

[0019]

[11] The heat storage structure according to any one of [1] to

[10] , wherein the storage section has a plurality of spaces partitioned by the porous wall, and the chemical heat storage material is stored in at least a portion of the spaces.

[0020]

[12] The heat storage structure described in any one of [1] to

[10] , wherein the storage section is a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall and defining a plurality of cells extending from a first end face to a second end face, and the chemical heat storage material is stored in at least a portion of the cells.

[0021]

[13] The heat storage structure according to

[12] , wherein plugging portions are provided on the first end face side and the second end face side of the cell in which the chemical heat storage material is accommodated.

[0022]

[14] The heat storage structure according to any one of [1] to

[13] , wherein the chemical heat storage material has a heat storage density of 200 kJ / kg or more.

[0023]

[15] The heat storage structure according to any one of [1] to

[14] , wherein the reaction medium is at least one selected from the group consisting of water, ammonia, alcohol, and carbon dioxide.

[0024]

[16] A heat storage structure according to any one of [1] to

[15] , A case portion that accommodates the heat storage structure; a storage tank for storing the reaction medium; a pipe connecting the case portion and the storage tank and through which the reaction medium flows; A heat storage device comprising: Effect of the Invention

[0025] According to the present invention, it is possible to provide a heat storage structure and a heat storage device capable of improving the heat input / output performance. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a cross-sectional view of a heat storage structure according to first and second embodiments of the present invention. [Figure 2a] 2 is an enlarged cross-sectional view of an area R1 within a dotted line frame in the heat storage structure according to the first embodiment of the present invention in FIG. [Figure 2b] 2 is an enlarged cross-sectional view of an area R2 within a dotted line frame in the heat storage structure according to the first embodiment of the present invention in FIG. [Figure 3a] FIG. 1 is a cross-sectional view of a heat storage structure according to a first embodiment of the present invention, in which a honeycomb structure is used as a storage portion. [Figure 3b] 3b is a cross-sectional view taken along line a-a' in FIG. 3a. [Figure 4] 1 is a schematic diagram illustrating the overall configuration of a heat storage device according to a first embodiment of the present invention. [Figure 5a] 1. FIG. 4 is an enlarged cross-sectional view of an area R1 within a dotted line frame in a heat storage structure according to a second embodiment of the present invention in FIG. [Figure 5b] 1. FIG. 4 is an enlarged cross-sectional view of the area R2 enclosed by the dotted line in the heat storage structure according to the second embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional view of a heat storage structure according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention relates to a heat storage structure that includes a chemical heat storage material capable of reversibly releasing heat through a binding reaction with a reaction medium and storing heat through a desorption reaction of the reaction medium, and a storage section that partitions and forms a space for storing the chemical heat storage material and has a porous wall extending from a first end face to a second end face, and the porous wall has two or more regions with different porosity. With this configuration, of the two or more regions with different porosity, the region with low porosity contributes to improving thermal conductivity, while the region with high porosity contributes to improving supply and release of the reaction medium. Therefore, this heat storage structure can improve the heat input / output performance, i.e., the heat output performance in the heat dissipation reaction and the heat input performance in the heat storage reaction.

[0028] The present invention also relates to a heat storage device including the above heat storage structure, a case for accommodating the heat storage structure, a storage tank for storing a reaction medium, and a pipe connecting the case and the storage tank and through which the reaction medium flows. Since the heat storage device includes the above heat storage structure, it is possible to improve heat input / output performance, i.e., heat output performance in a heat dissipation reaction and heat input performance in a heat storage reaction.

[0029] Hereinafter, embodiments of the heat storage structure and the heat storage device of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements to the following embodiments, as appropriate, based on the ordinary knowledge of a person skilled in the art, fall within the scope of the present invention, without departing from the spirit of the present invention.

[0030] (Embodiment 1) <Heat storage structure> Fig. 1 is a cross-sectional view (a cross-sectional view parallel to the direction in which the space of the storage unit extends) of the heat storage structure according to the first embodiment of the present invention. Figs. 2a and 2b are enlarged cross-sectional views of R1 and R2 within the dotted frame in Fig. 1. 1, the heat storage structure includes a chemical heat storage material (10) and a storage section (20) that defines a space (21) for storing the chemical heat storage material (10) and has a porous wall (24) extending from a first end face (22) to a second end face (23). In addition, plugging sections (25) are provided on the first end face (22) and the second end face (23). 1 shows an example in which plugging portions (25) are provided on the first end face (22) and the second end face (23), but as long as the outflow of the chemical thermal storage material (10) can be suppressed, the plugging portions (25) do not have to be provided, or the plugging portions (25) may be provided on only one of the first end face (22) or the second end face (23). In addition, while FIG. 1 shows an example in which the storage section (20) has a plurality of spaces (21), it may have a single space (21).

[0031] In the heat storage structure having the above structure, in the case where the reaction medium is supplied from the first end surface (22) side in the heat dissipation reaction, the reaction medium flows into the space (21) through the porous wall (24) and comes into contact with the chemical heat storage material (10). The chemical heat storage material (10) that comes into contact with the reaction medium dissipates heat (generates heat) through a binding reaction with the reaction medium. In the heat dissipation reaction, the white arrows in FIG. 1 indicate the flow direction of the reaction medium. The heat generated by this reaction is conducted to the outside of the heat storage structure through the porous wall (24). On the other hand, in the heat storage reaction, when heat is supplied from the second end surface (23) side, the heat is conducted to the chemical heat storage material (10) through the porous wall (24), and a desorption reaction of the reaction medium occurs due to heating of the chemical heat storage material (10). The reaction medium generated by this reaction is released to the outside of the heat storage structure through the porous wall (24).

[0032] The porous wall (24) has two or more regions with different porosities. Specifically, as shown in Figs. 2a and 2b, the porous wall (24) has a region A (24a) and a region B (24b) with different porosities. The region A (24a) has a larger porosity than the region B (24b). Note that Fig. 2a shows an example in which one region A (24a) and two regions B (24b) exist, and Fig. 2b shows an example in which one region A (24a) and one region B (24b) exist, but the number of regions A (24a) and regions B (24b) is not limited to these examples. For example, two or more regions A (24a) and two or more regions B (24b) may alternately exist. The region A (24a) and the region B (24b) are provided in a direction (D1) perpendicular to the contact surface (P1) between the chemical thermal storage material (10) and the porous wall (24). The region A (24a) and the region B (24b) are layered. The region B (24b) is located on the side of the contact surface (P1) between the chemical thermal storage material (10) and the porous wall (24).

[0033] By providing the porous wall (24) having the above structure, the reaction medium is easily allowed to flow into the entire region A (24a) having a large porosity (for example, from the first end surface (22) to the second end surface (23)) in the heat dissipation reaction. As a result, the reaction medium that has flowed into the region A (24a) is easily allowed to enter the space (21) that accommodates the chemical heat storage material (10) via the region B (24b), and the amount of the reaction medium supplied to the chemical heat storage material (10) is increased. In addition, the heat generated in the chemical heat storage material (10) is efficiently conducted to the outside of the heat storage structure via the region B (24b) having a small porosity. In particular, since the region B (24b) having a small porosity has a high thermal conductivity, the thermal resistance of the porous wall (24) can be reduced by providing the region B (24b) on the contact surface (P1) side between the chemical heat storage material (10) and the porous wall (24), and therefore the heat output performance in the heat dissipation reaction can be improved. On the other hand, in the case where heat is supplied from the second end surface (23) side in the heat storage reaction, the supplied heat is conducted to the chemical heat storage material (10) via the region B (24b) with low porosity, and the chemical heat storage material (10) is efficiently heated. In addition, the reaction medium generated by heating the chemical heat storage material (10) is efficiently released to the outside of the heat storage structure via the region B (24b) and the region A (24a) with high porosity. In this way, the heat input performance in the heat storage reaction can be improved.

[0034] In addition, since the porous wall (24) has a region A (24a) with a large porosity and a region B (24b) with a small porosity, the heat capacity of the porous wall (24) is in an appropriate range. Therefore, the heat of the chemical heat storage material (10) can be efficiently used in the heat dissipation reaction. In particular, even if the heat dissipation reaction is performed continuously, the porous wall (24) is not easily cooled, so that the heat can be easily used effectively. In addition, the heat can be efficiently conducted to the chemical heat storage material (10) in the heat storage reaction. Furthermore, since the rigidity of the porous wall (24) is good, durability and reliability can be improved.

[0035] The ratio of the porosity of region A (24a) to the porosity of region B (24b) is not particularly limited, but is preferably 1.01 to 90, more preferably 1.05 to 70, and even more preferably 1.1 to 50. By controlling the porosity ratio in such a range, it is possible to improve the heat input / output performance, particularly the heat output performance in the heat dissipation reaction. In this specification, the term "porosity" refers to the porosity measured by mercury intrusion porosimetry in accordance with JIS R1655:2003.

[0036] The porosity of region A (24a) is not particularly limited as long as it satisfies the above porosity ratio, but is preferably 30% to 90%, more preferably 40% to 90%, even more preferably 50% to 90%, and particularly preferably 60% to 90%. By controlling the porosity of region A (24a) within such a range, it is possible to improve the heat input / output performance, especially the heat output performance in the heat dissipation reaction.

[0037] Region A (24a) may have two or more subregions with different porosities. That is, region A (24a) may be formed of two or more layers (subregions) with different porosities within a range that satisfies the porosity of region A (24a). Region A (24a) may also be configured to have a distribution in which the porosity gradually increases or decreases along the thickness direction of the layer. In addition, in FIGS. 2a and 2b, the region A (24a) is shown as a smooth layer, but it may be a layer having an uneven shape such as a wavy shape.

[0038] The thickness of region A (24a) is not particularly limited, but is generally 0.00254 mm to 0.381 mm (0.1 mil to 15 mil), preferably 0.0254 mm to 0.254 mm (1 mil to 10 mil). By controlling the thickness within such a range, the above effects can be easily ensured.

[0039] The porosity of region B (24b) is not particularly limited as long as it satisfies the above porosity ratio, but is preferably 1% to 60%, more preferably 1% to 50%, even more preferably 1% to 40%, and particularly preferably 1% to 30%. By controlling the porosity of region B (24b) within such a range, it is possible to improve the heat input / output performance, especially the heat output performance in the heat dissipation reaction.

[0040] Region B (24b) may have two or more subregions with different porosities. That is, region B (24b) may be formed of two or more layers (subregions) with different porosities within a range that satisfies the porosity of region B (24b). Region B (24b) may also be configured to have a distribution in which the porosity is successively higher or lower in a specific direction. In addition, although region B (24b) is shown as a smooth layer in FIGS. 2a and 2b, it may be a layer having an uneven shape such as a wavy shape.

[0041] The thickness of region B (24b) is not particularly limited, but is generally 0.01 mm to 1.4 mm, preferably 0.01 mm to 1 mm, and more preferably 0.01 mm to 0.5 mm. By controlling the thickness within such a range, the above effects can be easily ensured.

[0042] The pore size of the porous wall (24) (i.e., region B (24b)) at the contact surface (P1) with the chemical heat storage material (10) is preferably smaller than the particle size of the chemical heat storage material (10). By controlling the pore size of region B (24b) in this manner, it is possible to prevent the chemical heat storage material (10) from flowing out from the heat storage structure. In this specification, the term "pore diameter" refers to the pore diameter in the pore distribution determined by mercury intrusion porosimetry in accordance with JIS R1655:2003.

[0043] The pore size of the region B (24b) is preferably smaller than the pore size of the region A (24a). By controlling the pore size in this manner, the capillary force in the region B (24b) can be increased. Therefore, in the heat dissipation reaction, the reaction medium flowing from the region A (24a) can be efficiently sucked up in the region B (24b) and supplied to the chemical heat storage material (10), thereby improving the heat output performance in the heat dissipation reaction.

[0044] The specific pore size of the region A (24a) is not particularly limited, but from the viewpoint of stably ensuring the above-mentioned effects, it is preferably 0.1 μm to 100 μm, and more preferably 0.5 μm to 50 μm. Furthermore, the specific pore size of the region B (24b) is not particularly limited, but from the viewpoint of stably ensuring the above-mentioned effects, it is preferably 0.1 μm to 100 μm, and more preferably 0.5 μm to 50 μm.

[0045] The shape of the storage section (20) is not particularly limited as long as it has the above characteristics, but it is preferable that the storage section (20) has a plurality of spaces (21) partitioned by a porous wall (24) and that the chemical heat storage material (10) is stored in at least a portion of the space (21) as shown in Fig. 1. With such a configuration, it is possible to increase the amount of the chemical heat storage material (10) stored in the storage section (20) while facilitating the supply of a reaction medium to the chemical heat storage material (10) in the heat dissipation reaction, thereby improving the heat input / output performance, particularly the heat output performance in the heat dissipation reaction.

[0046] The above-mentioned structure can be easily realized by using a honeycomb structure as the container portion (20). FIG. 3a is a cross-sectional view (a cross-sectional view parallel to the extension direction of the cells) of a heat storage structure using a honeycomb structure as the storage section (20), and FIG. 3b is a cross-sectional view along line a-a' in FIG. 3a (a cross-sectional view perpendicular to the extension direction of the cells). As shown in Figures 3a and 3b, the honeycomb structure (30) has an outer peripheral wall (31) and partition walls (35) disposed inside the outer peripheral wall (31) and defining a plurality of cells (34) extending from a first end face (32) to a second end face (33). A chemical thermal storage medium (10) is accommodated in at least a portion of the cells (34) of the honeycomb structure (30). Furthermore, plugging portions (25) are provided on the first end face (32) side and the second end face (33) side of the cells (34) containing the chemical thermal storage medium (10). 3a and 3b show an example in which the chemical heat storage material (10) is accommodated in a portion of the cells (34), but the chemical heat storage material (10) may be accommodated in all of the cells (34). In addition, as long as the outflow of the chemical heat storage material (10) can be suppressed, the plugging portion (25) does not need to be provided, or may be provided on either the first end face (32) or the second end face (33).

[0047] The shape (external shape) of the honeycomb structure 30 is not particularly limited and may be various shapes. Examples of the shape (external shape) of the honeycomb structure 30 include a circular cylinder, an elliptical cylinder, a square cylinder, or other polygonal cylinders.

[0048] The partition walls (35) are not particularly limited, and may have a first partition wall extending in the radial direction (diameter direction) and a second partition wall extending in the circumferential direction in a cross section perpendicular to the extension direction of the cells (34). With such a configuration, heat from the chemical thermal storage material (10) held in the cells (34) can be efficiently transferred to the outer peripheral wall (31).

[0049] The thickness of the outer peripheral wall 31 is preferably greater than the thickness of the partition wall 35. This configuration can increase the strength of the outer peripheral wall 31, which is susceptible to damage (e.g., cracks, fractures, etc.) due to external impact, thermal stress, etc. The thickness of the outer peripheral wall (31) is preferably more than 0.3 mm and not more than 10 mm, more preferably 0.5 mm to 5 mm, and even more preferably 1 mm to 3 mm. The thickness of the partition walls (35) is preferably 0.1 mm to 3 mm, more preferably 0.1 mm to 2 mm, and even more preferably 0.1 mm to 1 mm. By making the thickness of the partition walls (35) 0.1 mm or more, the mechanical strength of the honeycomb structure (30) can be made sufficient. In addition, by making the thickness of the partition walls (35) 3 mm or less, a decrease in the capacity of the chemical heat storage material (10) due to a decrease in the opening area can be suppressed.

[0050] The material of the outer peripheral wall (31) and the partition wall (35) is not particularly limited, but it is preferable that the main component of the material is ceramics. In this specification, the phrase "containing ceramics as a main component" means that the mass ratio of ceramics to the total mass is 50 mass % or more.

[0051] The outer peripheral wall 31 and the partition wall 35 preferably contain, as a main component, silicon carbide (SiC), which has high thermal conductivity. Since SiC has excellent resistance to high temperatures and chemicals, it becomes possible to use various types of chemical heat storage materials 10 and reaction media. In this specification, "containing SiC (silicon carbide) as a main component" means that the mass ratio of SiC (silicon carbide) to the total mass is 50 mass % or more.

[0052] More specifically, the materials that can be used for the outer peripheral wall 31 and the partition wall 35 include Si-impregnated SiC, (Si+Al)-impregnated SiC, metal composite SiC, recrystallized SiC, Si3N4, and SiC. Among these, it is preferable to use Si-impregnated SiC and (Si+Al)-impregnated SiC because of their high thermal conductivity.

[0053] The cell density (i.e., the number of cells (34) per unit area) in a cross section perpendicular to the extension direction of the cells (34) of the honeycomb structure (30) is not particularly limited and may be appropriately adjusted. 2 The cell density is preferably in the range of 4 cells / cm. 2 By satisfying the above, it is possible to sufficiently ensure the strength of the partition walls (35), and further the strength and effective GSA (geometric surface area) of the honeycomb structure (30) itself.

[0054] The isostatic strength of the honeycomb structure 30 is not particularly limited, but is preferably more than 1 MPa, more preferably 2 MPa or more, and even more preferably 5 MPa or more. When the isostatic strength of the honeycomb structure 30 exceeds 1 MPa, the honeycomb structure 30 has excellent durability. The isostatic strength of the honeycomb structure 30 can be measured in accordance with the method for measuring isostatic fracture strength specified in JASO standard M505-87, an automotive standard issued by the Society of Automotive Engineers of Japan.

[0055] The diameter (outer diameter) of the outer peripheral wall (31) in a cross section perpendicular to the extension direction of the cells (34) of the honeycomb structure (30) is not particularly limited, but is preferably 20 mm to 200 mm, and more preferably 30 mm to 100 mm. By setting the diameter in this range, it is possible to improve the heat storage efficiency. When the outer peripheral wall (31) is not circular, the diameter of the outer peripheral wall (31) is defined as the diameter of the maximum circle inscribed in the cross-sectional shape of the outer peripheral wall (31).

[0056] The method of housing the chemical heat storage material (10) housed in the space (21) such as the cell (34) is not particularly limited, and various methods can be used. For example, the chemical heat storage material (10) may be applied to and fixed on a porous wall (24) (e.g., partition wall (35)) that defines the space (21), or the chemical heat storage material (10) may be filled into the space (21). When the chemical heat storage material (10) is applied to and fixed on the porous wall (24), it is sufficient that a layer of the chemical heat storage material (10) is formed on the surface of the porous wall (24), and there may be a portion in the central region of the space (21) where the chemical heat storage material (10) is not present. However, it is preferable that the chemical heat storage material (10) is filled in the space (21). By filling the space (21) with the chemical heat storage material (10), the capacity of the chemical heat storage material (10) is increased, and the heat input / output performance, in particular the heat output performance in the heat dissipation reaction, can be improved.

[0057] The position of the cells (34) in which the chemical heat storage material (10) is held in the honeycomb structure (30) is not particularly limited. For example, in a cross section perpendicular to the extension direction of the cells (34), the chemical heat storage material (10) can be evenly accommodated in all the cells (34) of the honeycomb structure (30). In addition, in a cross section perpendicular to the extension direction of the cells (34), the chemical heat storage material (10) may be accommodated almost evenly on the center side and the outer periphery side of the honeycomb structure (30), the chemical heat storage material (10) may be accommodated mainly on the outer periphery side of the honeycomb structure (30), or the chemical heat storage material (10) may be accommodated mainly on the center side of the honeycomb structure (30).

[0058] The material of the plugging portions (25) in the honeycomb structure (30) is not particularly limited, and the same material as that of the outer peripheral wall (31) and the partition walls (35) can be used. The plugging portions (25) may also be formed using a resin sheet, a metal mesh, or the like. The method of forming the plugging portions (25) is not particularly limited, and can be performed according to a known method.

[0059] The ratio of the cells (34) containing the chemical thermal storage material (10) to all the cells (34) of the honeycomb structure (30) is not particularly limited, but the higher the ratio, the higher the heat input / output performance. The ratio is preferably 10% or more, more preferably 30% or more, even more preferably 50% or more, and particularly preferably 80% or more. However, if the ratio is too high, it becomes difficult for the reaction medium to come into contact with the chemical thermal storage material (10), so the ratio is preferably 90% or less.

[0060] The chemical heat storage material (10) is not particularly limited as long as it is capable of reversibly releasing heat through a bonding reaction with the reaction medium and storing heat through a desorption reaction of the reaction medium, and any material known in the art can be used. For example, it is preferable to use a chemical heat storage material (10) having a heat storage density of 200 kJ / kg or more. Examples of the chemical heat storage material (10) include hydroxides of alkali metals such as NaOH and LiOH; hydroxides of alkaline earth metals such as Ca(OH)2 and Mg(OH)2; ammonia complexes such as MgCl2·2NH3 and CaCl2·4NH3, and carbonates such as MgCO3 and CaCO3. These are selected according to the type of reaction medium and can be used alone or in combination of two or more. For example, hydroxides of alkali metals and hydroxides of alkaline earth metals are used when the reaction medium is water (including water vapor). Ammonia complexes are used when the reaction medium is ammonia. Carbonates are used when the reaction medium is carbon dioxide. In particular, when the heat storage device in which the heat storage structure is used is for vehicle use, it is preferable that the reaction medium is water, and therefore the chemical heat storage material (10) is preferably at least one selected from hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0061] The shape of the chemical thermal storage material (10) filled in the cells (34) is not particularly limited, and may be various shapes such as powder, granules, rods, etc. When the chemical thermal storage material (10) is applied to and fixed on the partition walls (35) that define the cells (34), a coating composition containing the chemical thermal storage material (10) and a binder may be used.

[0062] The reaction medium may be anything that causes a chemical reaction (heat dissipation reaction) upon contact with the chemical heat storage material (10), and water (including water vapor), ammonia, alcohol, carbon dioxide, etc. may be used. These may be used alone or in combination of two or more. Among these, water is advantageous in terms of availability and ease of handling. In addition, no special equipment is required when constructing the heat storage device, and it is easy to deal with leakage, etc., so that equipment costs and operating costs can be reduced. In particular, when the heat storage device is for use in a vehicle, it is preferable that the reaction medium is water from the above-mentioned viewpoints.

[0063] When water is used as the reaction medium, the type of water is not particularly limited. For example, in addition to clean water (tap water) and well water, distilled water, ion-exchanged water, etc. can be used as appropriate. However, since the reaction medium is used repeatedly in the heat storage device, it is preferable that the reaction medium is water (e.g., ion-exchanged water) from which components such as organic matter have been removed and which can be used for a long period of time. By using such water, it is possible to suppress the accumulation of organic matter and the like in the heat storage device, and therefore it is not necessary to replace the water for a long period of time.

[0064] The heat storage structure according to the first embodiment of the present invention can be manufactured in accordance with a method known in the art. As an example, a method for manufacturing a heat storage structure using a honeycomb structure 30 as the container 20 will be described. First, a clay containing ceramic powder is extruded into a desired shape to produce a honeycomb molded body. At this time, by selecting an appropriate type of die and jig, the shape and density of the cells (34), the shape and thickness of the outer peripheral wall (31) and the partition walls (35), etc. can be controlled. The above-mentioned ceramics can be used as the material for the honeycomb molded body. For example, when manufacturing a honeycomb molded body mainly composed of SiC, a binder, water and / or an organic solvent are added to a predetermined amount of SiC powder, and the resulting mixture is kneaded to form a clay (ceramic material), which is then molded to obtain a honeycomb molded body of a desired shape. The obtained honeycomb molded body is then dried and fired in a reduced pressure inert gas or in vacuum to obtain a honeycomb structure (30) having cells (34) partitioned and formed by partition walls (35).

[0065] Here, the honeycomb structure (30) including the partition walls (35) having the region A (24a) and the region B (24b) can be produced by first producing the honeycomb structure (30) having the partition walls (35) composed only of the region A (24a), and then forming a layer composed of the region B (24b) on the surface of the partition walls (35). For example, a ceramic material that provides the layer that becomes the region B (24b) can be applied to the surface of the partition walls (35) composed only of the region A (24a) and then fired. The porosity and pore size of the region A (24a) and the region B (24b) can be controlled within an appropriate range by adding a component such as a pore-forming agent. Next, the chemical heat storage material (10) is accommodated in the cells (34) of the honeycomb structure (30) obtained as described above. The above-mentioned method can be used as the accommodation method. When filling the chemical heat storage material (10) in some of the cells (34) of the honeycomb structure (30), plugging portions (25) may be formed at one end of the cells (34) to be filled with the chemical heat storage material (10), and then the chemical heat storage material (10) may be filled from the other end, and the plugging portions (25) may be formed at the other end.

[0066] The heat storage structure according to the first embodiment of the present invention has excellent heat input / output performance, and therefore can be used as a heat storage section of a heat storage device used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, factory heat exhaust equipment, etc. Among these, this heat storage structure is suitable for use as a heat storage section of a heat storage device used in vehicles such as automobiles.

[0067] <Thermal storage device> FIG. 4 is a schematic diagram showing the overall configuration of the heat storage device according to the first embodiment of the present invention. 4, the heat storage device according to the first embodiment of the present invention includes the above-mentioned heat storage structure (100), a case (110) that houses the heat storage structure (100), a storage tank (120) that stores the reaction medium R, and a pipe (130) that connects between the case (110) and the storage tank (120) and through which the reaction medium R flows. Since this heat storage device includes the above-mentioned heat storage structure (100), it is possible to improve the heat input / output performance, i.e., the heat output performance in the heat dissipation reaction and the heat input performance in the heat storage reaction. Although FIG. 4 shows an example in which one heat storage structure (100) is housed in the case portion (110), two or more heat storage structures (100) may be housed in the case portion (110).

[0068] The case part (110) is a member that houses the heat storage structure (100). Therefore, the case part (110) is not particularly limited as long as it has a structure that can house the heat storage structure (100). For example, the shape of the case part (110) may be appropriately selected depending on the shape of the heat storage structure (100) to be housed, and may be various shapes such as a cylindrical shape or a rectangular tube shape. Note that, although the case part (110) is shown as one member in FIG. 4, the case part (110) may be composed of two or more members. For example, the case part (110) may be composed by combining a main body part and a lid part.

[0069] The case (110) has a communication port (111) through which the reaction medium R can be supplied from the storage tank (120) and the reaction medium R can be recovered to the storage tank (120). The number of communication ports (111) may be one as shown in FIG. 4, or may be two. The communication port (111) is preferably provided so as to face the first end face or the second end face of the heat storage structure (100). By providing the communication port (111) at such a position, the reaction medium R can be easily supplied and recovered.

[0070] The material of the case part (110) is not particularly limited, but is preferably a metal from the viewpoint of manufacturability. In addition, if the case part (110) is made of a metal, it is advantageous in that it can be easily welded to other members. For example, stainless steel, titanium alloy, copper alloy, aluminum alloy, brass, etc. can be used as the material of the case part (110). Among them, stainless steel is preferable because it is highly durable, reliable, and inexpensive.

[0071] The thickness of the case part (110) is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more. By making the thickness of the case part (110) 0.1 mm or more, durability and reliability can be ensured. Furthermore, the thickness of the case part (110) is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. By making the thickness of the case part (110) 10 mm or less, thermal resistance can be reduced and thermal conductivity can be increased.

[0072] The storage tank (120) is a member capable of supplying the reaction medium R to the case portion (110) and recovering the reaction medium R from the case portion (110). That is, the storage tank (120) has a tank structure or a vessel structure provided with a space therein capable of storing the reaction medium R that chemically reacts with the chemical heat storage material (10), and is provided with a supply port (121) and a recovery port (122) for the reaction medium R. The case portion (110) and the storage tank (120) are connected by at least one pipe (130).

[0073] The material constituting the storage tank (120) is not particularly limited as long as it is not corroded by the reaction medium R and has a strength sufficient not to be damaged during use. Typical examples of the material include metal materials, resin materials, and combinations of these materials.

[0074] The pipe (130) is provided with a cooling section (140) for cooling and liquefying the gaseous reaction medium R generated during the heat storage reaction. The cooling section (140) is not particularly limited, and any known cooling device can be used. For example, an air-cooling type cooling device that has multiple heat sinks and can cool by increasing the contact area with the outside air, or a refrigerant type cooling device that can cool by contact with water or other refrigerants can be used.

[0075] The reaction medium R supplied from the storage tank (120) into the case portion (110) may be in a gaseous or liquid state. When the reaction medium R supplied from the storage tank (120) to the case part (110) is in a gaseous state, as shown in Fig. 4, it is preferable that the pipe (130) connected to one communication port (111) of the case part (110) branches into two on the way and is connected to the supply port (121) and the recovery port (122) of the storage tank (120), respectively. In addition, it is preferable that the branch part of the pipe (130) is provided with a valve (150) for switching the flow path of the reaction medium R flowing through the pipe (130) to the supply port (121) side or the recovery port (122) side. By switching the valve (150) to open the flow path on the supply port (121) side during the exothermic reaction, the gaseous reaction medium R can be supplied to the case part (110). At this time, for example, by providing a decompression mechanism (for example, a decompression device such as a suction pump for decompressing the inside of the case part (110)) for reducing the pressure on the case part (110), the gaseous reaction medium R can be smoothly supplied to the case part (110). Note that, by switching the valve (150) so as to open the flow path on the recovery port (122) side during the heat storage reaction, the reaction medium R can be recovered from inside the case part (110).

[0076] In addition, when the reaction medium R supplied from the storage tank (120) to the case portion (110) is in a gaseous state, a heater (160) for vaporizing the reaction medium R is provided in the storage tank (120) as shown in Fig. 4. The heater (160) is electrically connected to a power source P, and the reaction medium R can be turned into a gaseous state by heating the reaction medium R with the heater (160).

[0077] On the other hand, when the reaction medium R supplied from the storage tank (120) to the case part (110) is in a liquid state, two communication ports (111) are provided in the case part (110), and the two communication ports (111) are connected to the supply port (121) and the recovery port (122) of the storage tank (120) by piping (130), respectively. It is also preferable to provide each piping (130) with a valve (150) capable of opening and closing each flow path. In the exothermic reaction, the liquid reaction medium R can be supplied to the case part (110) by opening the valve (150) provided in the piping (130) connecting the communication port (111) of the case part (110) and the supply port (121) of the storage tank (120). In addition, during the heat storage reaction, the reaction medium R can be recovered from inside the case portion (110) by opening a valve (150) provided in the pipe (130) connecting the communication port (111) of the case portion (110) and the recovery port (122) of the storage tank (120).

[0078] In the heat storage device having the above-mentioned configuration, the heat storage reaction is carried out by heating the heat storage structure (100) in the case portion (110). There is no particular limitation on the method for heating the heat storage structure 100, and various methods can be used. For example, the heat storage structure 100 may be heated by arranging a heater or a pair of electrodes in contact with at least a part of the heat storage structure 100. The heater is not particularly limited, and any known heater such as a band heater, a wire heater, a sheet heater, or a far-infrared heater can be used. When a pair of electrodes is used, the positions of the pair of electrodes are not particularly limited. For example, when a heat storage structure (100) having a honeycomb structure (30) as the storage section (20) is used, a pair of electrodes can be provided on the surface of the outer wall (31) parallel to the extension direction of the cells (34) of the honeycomb structure (30) or on both end faces (first end face (32) and second end face (33)). The material of the pair of electrodes is not particularly limited, and for example, a material (metal or alloy) containing one or more selected from aluminum (Al), stainless steel (SUS), nickel (Ni), silver (Ag), and copper (Cu) can be used. In addition, an ohmic electrode capable of making ohmic contact with the outer wall (31) or the partition wall (35) can be used. For example, an ohmic electrode containing at least one selected from Al, Au, Ag, and In as a base metal and at least one selected from Ni, Si, Zn, Ge, Sn, Se, and Te for n-type semiconductors as a dopant can be used. The pair of electrodes may have a single-layer structure or a laminated structure of two or more layers. When the pair of electrodes has a laminated structure of two or more layers, the materials of the layers may be the same or different.

[0079] As a method for heating the heat storage structure (100), a configuration may be adopted in which a heating gas supply port is provided in the case portion (110) and the heating gas supply port is connected to a pipe through which the heating gas flows, thereby allowing the heating gas to flow. With such a configuration, the heat storage structure (100) can be heated by supplying the heating gas into the case portion (110). The heating gas supply port is not particularly limited, but is preferably provided on the surface of the case part (110) facing the first end surface (32) or the second end surface (33) of the heat storage structure (100).

[0080] The heated gas is not particularly limited, but may be gas heated by an internal combustion engine and / or a heater. Specific examples of the heated gas include exhaust gas discharged from an internal combustion engine and gas (air or exhaust gas) heated by various heaters. The latter gas includes exhaust gas heated by an electrically heated catalyst device (EHC). Among these, by using heated exhaust gas, it is possible to effectively utilize the heat of the exhaust gas and to carry out a heat storage process during driving.

[0081] When the heat storage structure (100) is heated in the heat storage reaction, the chemical heat storage material (10) changes due to an endothermic reaction (for example, a dehydration reaction). For example, when Ca(OH)2 is used as the chemical heat storage material (10), it changes to CaO due to an endothermic reaction (dehydration reaction). Similarly, when Mg(OH)2 is used as the chemical heat storage material (10), it changes to MgO due to an endothermic reaction (dehydration reaction). CaO and MgO can maintain their original state even when the temperature drops, as long as they are not in contact with water as the reaction medium R. The reaction medium R (water vapor) produced by the heat storage reaction passes through the pipe (130), is cooled and liquefied in the cooling section (140), and is collected in the storage tank (120).

[0082] The exothermic reaction is carried out by supplying the reactive medium R to the case portion (110) and bringing the reactive medium R into contact with the chemical heat storage material (10). For example, in the heat storage device shown in FIG. 4, the valve (150) is switched to open the flow path on the supply port (121) side, and the reactive medium R is heated by the heater (160) to gasify the reactive medium R, so that the gaseous reactive medium R can be supplied into the case portion (110). When the reactive medium R is brought into contact with the chemical heat storage material (10), an exothermic reaction (e.g., hydration reaction) occurs, generating heat.

[0083] The heat storage device according to the first embodiment of the present invention has excellent heat input / output performance, and can be used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, and heat exhaust equipment in factories. Among these, this heat storage structure is suitable as a heat storage device used in vehicles such as automobiles. As the vehicle, it is particularly preferable that it is an electric vehicle such as an EV (electric vehicle) or a HEV (hybrid electric vehicle).

[0084] (Embodiment 2) <Heat storage structure> The heat storage structure according to the second embodiment of the present invention differs from the heat storage structure according to the first embodiment of the present invention in that the region A (24a) is located on the side of the contact surface (P1) between the chemical heat storage material (10) and the porous wall (24). Therefore, the cross-sectional view (cross-sectional view parallel to the extension direction of the space of the storage section) of the heat storage structure according to the second embodiment of the present invention is similar to that of Fig. 1, but the enlarged cross-sectional view of R1 and R2 within the dotted line frame in Fig. 1 differs from the heat storage structure according to the first embodiment of the present invention. Hereinafter, differences from the heat storage structure according to the first embodiment of the present invention will be described. In addition, since components having the same reference numerals as those appearing in the description of the heat storage structure according to embodiment 1 of the present invention are the same as the components of the heat storage structure according to embodiment 1 of the present invention, detailed descriptions thereof will be omitted.

[0085] 5a and 5b are enlarged cross-sectional views of R1 and R2 within the dotted lines in FIG. As shown in Figs. 5a and 5b, the porous wall (24) has a region A (24a) and a region B (24b) with different porosities. The region A (24a) has a larger porosity than the region B (24b). Note that Fig. 5a shows an example in which there are two regions A (24a) and one region B (24b), and Fig. 5b shows an example in which there is one region A (24a) and one region B (24b), but the number of regions A (24a) and regions B (24b) is not limited to these examples. For example, there may be two or more regions A (24a) and two or more regions B (24b) alternately. The region A (24a) and the region B (24b) are provided in a direction (D1) perpendicular to the contact surface (P1) between the chemical thermal storage material (10) and the porous wall (24). The region A (24a) and the region B (24b) are layered. The region A (24a) is located on the side of the contact surface (P1) between the chemical thermal storage material (10) and the porous wall (24).

[0086] By providing the porous wall (24) having the above-mentioned structure, in the heat dissipation reaction, the reaction medium easily flows into the inside of the storage section (20) through the region A (24a) facing the space (21) that stores the chemical heat storage material (10), and the amount of the reaction medium supplied to the chemical heat storage material (10) is increased. In addition, the heat generated in the chemical heat storage material (10) is efficiently conducted to the outside of the heat storage structure through the region B (24b) with low porosity. In particular, since the reaction medium easily flows through the region A (24a) with high porosity, a large amount of the reaction medium can be supplied to the chemical heat storage material (10), and the chemical heat storage material (10) easily generates heat, and therefore the heat output performance in the heat dissipation reaction can be improved. On the other hand, in the case where heat is supplied from the second end surface (23) side in the heat storage reaction, the supplied heat is conducted to the chemical heat storage material (10) via the region B (24b) with low porosity, and the chemical heat storage material (10) is efficiently heated. In addition, the reaction medium generated by heating the chemical heat storage material (10) is efficiently released to the outside of the heat storage structure via the region B (24b) and the region A (24a) with high porosity. In this way, the heat input performance in the heat storage reaction can be improved.

[0087] In addition, since the porous wall (24) has a region A (24a) with a large porosity and a region B (24b) with a small porosity, the heat capacity of the porous wall (24) is in an appropriate range. Therefore, the heat of the chemical heat storage material (10) can be efficiently used in the heat dissipation reaction. In particular, even if the heat dissipation reaction is performed continuously, the porous wall (24) is not easily cooled, so that the heat can be easily used effectively. In addition, the heat can be efficiently conducted to the chemical heat storage material (10) in the heat storage reaction. Furthermore, since the rigidity of the porous wall (24) is good, durability and reliability can be improved.

[0088] The details of the region A (24a) and the region B (24b) (such as porosity, porosity ratio, pore size, etc.) can be similar to those of the heat storage structure according to the first embodiment of the present invention.

[0089] The heat storage structure according to the second embodiment of the present invention can be manufactured in accordance with a method known in the art, similarly to the heat storage structure according to the first embodiment of the present invention. The honeycomb structure (30) having partition walls (35) having region A (24a) and region B (24b) can be produced by producing a honeycomb structure (30) having partition walls (35) consisting only of region B (24b), and then forming a layer consisting of region A (24a) on the surface of this partition wall (35). For example, a ceramic material that provides a layer that becomes region A (24a) may be applied to the surface of the partition wall (35) consisting only of region B (24b) and then fired. The porosity and pore size of region A (24a) and region B (24b) can be controlled within an appropriate range by adding a component such as a pore-forming agent.

[0090] The heat storage structure according to the second embodiment of the present invention has excellent heat input / output performance, and therefore can be used as a heat storage section of a heat storage device used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, factory heat exhaust equipment, etc. Among these, this heat storage structure is suitable for use as a heat storage section of a heat storage device used in vehicles such as automobiles.

[0091] <Thermal storage device> The heat storage device according to the second embodiment of the present invention differs from the heat storage device according to the first embodiment of the present invention in that the heat storage structure according to the second embodiment of the present invention is used. Therefore, the basic structure of the heat storage device according to the second embodiment of the present invention is the same as that of the heat storage device according to the first embodiment of the present invention, and therefore a detailed description thereof will be omitted. The heat storage device according to the second embodiment of the present invention is excellent in heat input / output performance because it uses the heat storage structure according to the second embodiment of the present invention. Therefore, the heat storage device according to the second embodiment of the present invention can be used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, and heat exhaust equipment in factories. Among these, this heat storage structure is suitable as a heat storage device used in vehicles such as automobiles. As the vehicle, it is particularly preferable that it is an electric vehicle such as an EV (electric vehicle) or an HEV (hybrid vehicle).

[0092] (Embodiment 3) <Heat storage structure> The heat storage structure of the third embodiment of the present invention differs from the heat storage structures of the first and second embodiments of the present invention in that it has an area A (24a) and an area B (24b) in a direction parallel to the contact surface (P1) between the chemical heat storage material (10) and the porous wall (24). Hereinafter, differences from the heat storage structure according to the first embodiment of the present invention will be described. In addition, since the components having the same reference numerals as those appearing in the description of the heat storage structure according to embodiment 1 of the present invention are the same as the components of the heat storage structure according to embodiments 1 and 2 of the present invention, detailed descriptions thereof will be omitted.

[0093] FIG. 6 is a cross-sectional view (a cross-sectional view parallel to the extension direction of the space of the storage section) of a heat storage structure according to a third embodiment of the present invention. As shown in FIG. 6, the porous wall (24) has a region A (24a) and a region B (24b) with different porosities. The region A (24a) has a higher porosity than the region B (24b). Although FIG. 6 shows an example in which there is one region A (24a) and one region B (24b), the number of regions A (24a) and regions B (24b) is not limited to these examples. For example, there may be two or more regions A (24a) and two or more regions B (24b) alternately. The region A (24a) and the region B (24b) are provided in a direction parallel to the contact surface (P1) between the chemical thermal storage medium (10) and the porous wall (24).

[0094] By providing the porous wall (24) having the above structure, when the reaction medium is supplied from the first end surface (22) side in the heat dissipation reaction, the reaction medium easily flows into the inside of the storage section (20) through the region A (24a) with high porosity, and the amount of the reaction medium supplied to the chemical heat storage material (10) increases. In addition, the heat generated in the chemical heat storage material (10) is efficiently conducted to the outside of the heat storage structure from the region B (24b) with low porosity. In particular, since the reaction medium easily flows through the region A (24a) with high porosity, a large amount of the reaction medium can be supplied to the chemical heat storage material (10), and the chemical heat storage material (10) easily generates heat, and the heat output performance in the heat dissipation reaction can be improved. Note that the white arrow in FIG. 6 indicates the flow direction of the reaction medium. On the other hand, in the heat storage reaction, when heat is supplied from the second end surface (23) side, the heat is conducted to the chemical heat storage material (10) through the region B (24b) with low porosity, and the chemical heat storage material (10) is efficiently heated. In addition, the reaction medium generated by heating the chemical heat storage material (10) is efficiently released to the outside of the heat storage structure through the region A (24a) with high porosity. In this way, the heat input performance in the heat storage reaction can be improved.

[0095] In addition, since the porous wall (24) has a region A (24a) with a large porosity and a region B (24b) with a small porosity, the heat capacity of the porous wall (24) is in an appropriate range. Therefore, the heat of the chemical heat storage material (10) can be efficiently used in the heat dissipation reaction. In particular, even if the heat dissipation reaction is performed continuously, the porous wall (24) is not easily cooled, so that the heat can be easily used effectively. In addition, the heat can be efficiently conducted to the chemical heat storage material (10) in the heat storage reaction. In addition, since the rigidity of the porous wall (24) is good, the durability and reliability can be improved. Furthermore, since the center of gravity of the heat storage structure is located on the side of the region B (24b) with a small porosity, the stability against vibration is improved, so that it can be suitably used in applications where vibration occurs.

[0096] The details of the region A (24a) and the region B (24b) (such as porosity, porosity ratio, pore size, etc.) can be similar to those of the heat storage structures according to the first and second embodiments of the present invention.

[0097] The heat storage structure according to the third embodiment of the present invention can be manufactured in accordance with a method known in the art, similarly to the heat storage structures according to the first and second embodiments of the present invention. The honeycomb structure (30) having partition walls (35) having region A (24a) and region B (24b) can be manufactured by preparing a honeycomb structure (30) having partition walls (35) consisting only of region A (24a) and a honeycomb structure (30) having partition walls (35) consisting only of region B (24b), and then bonding their end faces together. The porosity and pore diameter of region A (24a) and region B (24b) can be controlled within an appropriate range by adding a component such as a pore-forming agent.

[0098] The heat storage structure according to the third embodiment of the present invention has excellent heat input / output performance, and therefore can be used as a heat storage section of a heat storage device used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, factory heat exhaust equipment, etc. Among these, this heat storage structure is suitable for use as a heat storage section of a heat storage device used in vehicles such as automobiles.

[0099] <Thermal storage device> The heat storage device according to the third embodiment of the present invention differs from the heat storage devices according to the first and second embodiments of the present invention in that the heat storage structure according to the third embodiment of the present invention is used. Therefore, the basic structure of the heat storage device according to the third embodiment of the present invention is the same as that of the heat storage devices according to the first and second embodiments of the present invention, and therefore a detailed description thereof will be omitted. The heat storage device according to the third embodiment of the present invention is excellent in heat input / output performance because it uses the heat storage structure according to the third embodiment of the present invention. Therefore, the heat storage device according to the third embodiment of the present invention can be used in various applications such as vehicles such as automobiles, air conditioning equipment, hot water supply equipment, and heat exhaust equipment in factories. Among these, this heat storage structure is suitable as a heat storage device used in vehicles such as automobiles. As the vehicle, it is particularly preferable that it is an electric vehicle such as an EV (electric vehicle) or an HEV (hybrid vehicle). EXAMPLES

[0100] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0101] The thermal resistance in the heat storage structure according to the first embodiment of the present invention was calculated. In this trial calculation, the storage section of the heat storage structure was a honeycomb structure, and the honeycomb structure had an outer diameter of 50 mm, a length in the cell extension direction of 100 mm, and a length of one side of the cell in a cross section perpendicular to the cell extension direction of 2 mm. In addition, the contact area between the chemical heat storage material stored in the cell and the partition wall (region B) was 0.0008 m 2 It was decided.

[0102] In the heat storage structure having the above-mentioned structure, the thermal resistance was calculated by changing the thickness and porosity of the partition walls (region A and region B). Thermal resistance (R total ) was calculated using the following formula: R total =R1+1 / (1 / R A1 +1 / (R B1 +R B2 +R B3 )) In the formula, R1 is the thermal resistance of the half region on the chemical thermal storage medium side in the thickness direction of region B, and R A1 is the thermal resistance in the plane direction of region B, and R B1 is the thermal resistance of the half of region A in the thickness direction of region B, and R B2 is the thermal resistance of 1 / 4 of the area on the side of area A in the thickness direction of area A, and R B3 is the thermal resistance in the surface direction of region A. In this calculation, it was assumed that the thermal conductivity of the partition walls (regions A and B) that had no pores was 150 W / mK, that the thermal conductivity changed linearly with respect to the porosity, and that the heat generation amount was 100 W.

[0103] Also, R1, R A1 , R B1 , R B2 and R B3 is calculated by the following formula: R1 = (thickness of region B [mil] / 2 × 0.0254) / (thermal conductivity of region B [W / mK] × contact area between chemical heat storage material and region B (0.0008 m 2 )) R A1 = (Outer diameter of honeycomb structure (50 mm) × 0.001 / 2) / (Thermal conductivity of region B [W / mK] × (Thickness of region B [mil] × 0.0254 × Length of honeycomb structure cell in extension direction (100 mm) / 10 6 )) R B1 =R1 R B2 = (Thickness of area A [mil] / 4 × 0.0254) / (Thermal conductivity of area A [W / mK] × Contact area between chemical heat storage material and area B (0.0008 m 2 )) R B3 = (Outer diameter of honeycomb structure (50 mm) × 0.001 / 2) / (Thermal conductivity of region A [W / mK] × (Thickness of region A [mil] × 0.0254 / 2 × Length of honeycomb structure cell in extension direction (100 mm) / 10 6 )) The results of the above calculations are shown in Table 1.

[0104] [Table 1]

[0105] In Table 1, the thermal resistance (R total ) based on the thermal resistance (R total ) decrease (ΔR total In this estimation, the porosity of each of the regions A and B was set so that the porosity was uniform with respect to the volume average of the honeycomb structure. As shown in Table 1, the heat storage structures (Nos. 2 to 18) having partition walls (porous walls) with regions A and B having different porosities have a lower thermal resistance (R total ) has become lower.

[0106] As can be seen from these results, the present invention can provide a heat storage structure and a heat storage device that can improve the heat input / output performance. [Explanation of symbols]

[0107] 10 Chemical heat storage material 20 Storage unit 21 Space 22 First end surface 23 Second end face 24 porous wall 24a Area A 24b Area B 25 Plugging part 30 Honeycomb structure 31 Outer wall 32 First end surface 33 Second end face 34 Cell 35 Bulkhead 100 Heat storage structure 110 Case part 111 Connecting port 120 Storage Tank 121 Supply port 122 Collection port 130 Piping 140 Cooling section 150 Valve 160 Heater

Claims

1. A chemical heat storage material capable of reversibly releasing heat through a bonding reaction with a reaction medium and storing heat through a desorption reaction of the reaction medium; A storage section that defines a space for storing the chemical thermal storage material and has a porous wall extending from a first end surface to a second end surface; Equipped with The heat storage structure, wherein the porous wall has two or more regions with different porosity.

2. 2. The heat storage structure according to claim 1, wherein the porous wall has at least an area A and an area B, and a ratio of the porosity of the area A to the porosity of the area B is 1.01 to 90.

3. The heat storage structure according to claim 2 , wherein the porous wall has the region A and the region B in a direction perpendicular to a contact surface between the chemical heat storage material and the porous wall.

4. The heat storage structure according to claim 3 , wherein the region A and the region B are layered.

5. The heat storage structure according to any one of claims 2 to 4, wherein the region B is located on a contact surface side between the chemical heat storage material and the porous wall.

6. The heat storage structure according to any one of claims 2 to 4, wherein the region A is located on a contact surface side between the chemical heat storage material and the porous wall.

7. The heat storage structure according to claim 2 , wherein the porous wall has the region A and the region B in a direction parallel to a contact surface between the chemical heat storage material and the porous wall.

8. The heat storage structure according to any one of claims 2 to 4 and 7, wherein the porosity of the region A is 30 to 90%.

9. The heat storage structure according to any one of claims 2 to 4 and 7, wherein the porosity of the region B is 1 to 60%.

10. The heat storage structure according to any one of claims 1 to 4 and 7, wherein a pore size of the porous wall at a contact surface with the chemical heat storage material is smaller than a particle size of the chemical heat storage material.

11. The storage section has a plurality of spaces partitioned by the porous wall, and the chemical heat storage material is stored in at least a portion of the spaces. The heat storage structure according to any one of claims 1 to 4 and 7.

12. The storage section is a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall and defining a plurality of cells extending from a first end face to a second end face, and the chemical heat storage material is contained in at least a portion of the cells. The heat storage structure according to any one of claims 1 to 4 and 7.

13. The heat storage structure according to claim 12 , wherein plugging portions are provided on the first end face side and the second end face side of the cell in which the chemical heat storage material is accommodated.

14. The heat storage structure according to any one of claims 1 to 4 and 7, wherein the chemical heat storage material has a heat storage density of 200 kJ / kg or more.

15. The heat storage structure according to any one of claims 1 to 4 and 7, wherein the reaction medium is at least one selected from the group consisting of water, ammonia, alcohol and carbon dioxide.

16. A heat storage structure according to any one of claims 1 to 4 and 7, A case portion that accommodates the heat storage structure; a storage tank for storing the reaction medium; a pipe connecting the case portion and the storage tank and through which the reaction medium flows; A heat storage device comprising:

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