JP2012197346A - Chemical heat accumulator and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical heat accumulator, wherein: the chemical heat-accumulating material structure held by a wall is prevented from adhering to the wall; and shear failure is prevented from occurring.SOLUTION: The chemical heat accumulator 100 includes: the chemical heat-accumulating material structure 21 that contains a granular chemical heat-accumulating material having a mean primary particle size of d [μm]; and a structure-housing member 30 that houses the chemical heat-accumulating material structure 21 and holds at least part of the material structure 21, wherein a ten-point surface roughness Rz [μm] in an inner wall surface abutting on the material structure 21, complying with JIS B 0601, is smaller than the mean primary particle size d.

Description

  The present invention relates to a chemical heat storage device using a chemical heat storage material responsible for heat absorption and release and a method for manufacturing the same.

  A chemical heat storage material, which is a substance that can absorb and release heat by using a chemical reaction, has been widely known, and its use is being studied in various fields.

  For example, a chemical heat storage material mainly composed of quick lime having a large number of pores is disclosed, and by having a large number of pores, compared with a conventional chemical heat storage material that has no excess space such as holes, It is said that volume expansion in the process of changing to slaked lime is absorbed and particle destruction and powdering are eliminated (see, for example, Patent Document 1).

JP-A-1-225686

However, in a system using a chemical heat storage material, for example, when calcium hydroxide is used as a chemical heat storage material as described above, the following reversible reaction between calcium oxide and calcium hydroxide is repeated during system operation. However, at this time, each particle is accompanied by expansion and contraction of a volume of several tens of percent.
CaO + H ₂ O Ｃａ Ca (OH) ₂
Therefore, it is expected that the particle breakage to some extent by having the pores as in the above-mentioned conventional technology, but in fact, the volume change is large only by having the pores, The fact is that the effects of volume expansion and contraction cannot be absorbed. Therefore, there is a problem that particles constituting the chemical heat storage material are collapsed by repeated volume changes, causing particles to be pulverized and causing separation and a decrease in reactivity.

  The present invention has been made in view of the above, and restrains the chemical heat storage material to limit the volume change, and prevents the restrained chemical heat storage material structure from adhering to the wall or the like of the housing member and shear breakage. An object is to provide a chemical regenerator and a method for producing the same, in which the above-mentioned is suppressed, and to achieve the object.

  In the present invention, when a chemical heat storage material structure, which is a molded product of a chemical heat storage material, is restrained by a wall or the like in a housing member so that volume change (expansion difference) due to expansion or the like does not occur remarkably, Shear stress is likely to occur between the material structure and the structure may be damaged internally. However, in order to suppress this stress and prevent damage to the chemical heat storage material, the primary particles of the chemical heat storage material The inventors have obtained the knowledge that it is important that the roughness of the wall surface that restrains the chemical heat storage material has a certain relationship with respect to the particle size, and this has been achieved based on such knowledge.

In order to achieve the object, the chemical heat accumulator which is the first invention is:
<1> A chemical heat storage material structure including a granular chemical heat storage material having an average primary particle size of d [μm], and the chemical heat storage material structure containing the chemical heat storage material structure and restraining at least a part thereof. A structure housing member having a ten-point surface roughness Rz [μm] based on JIS B 0601 of the inner wall surface in contact with the body is smaller than the average primary particle diameter d.

  In the first invention, the average primary particle diameter d of the particles of the chemical heat storage material forming the chemical heat storage material structure which is a molded body accommodates the chemical heat storage material structure and restricts at least a part thereof. When the volume of the housing member is repeatedly changed during the reaction of the chemical heat storage material by being larger than Rz (ten-point surface roughness according to JIS B 0601; μm) on the inner wall surface in contact with the chemical heat storage material structure The particles of the chemical heat storage material are prevented from entering and fixing into the concave gaps on the wall surface. This prevents the shear between the wall and the chemical heat storage material structure even when the structure is constrained by the inner wall of the housing member in order to prevent the volume change due to significant expansion and contraction of the chemical heat storage material during the reaction. Therefore, the chemical heat storage material is prevented from being damaged under the influence of shear stress, and the durability of the chemical heat storage material is improved. In addition, the chemical heat storage material is not easily broken when it is attached / detached (exchanged), and the attachment / detachment / exchangeability is improved.

  In the present invention, “restraint” means limiting significant expansion and contraction during use of the chemical heat storage material structure. Specifically, shrinkage of the chemical heat storage material structure due to desorption (for example, dehydration) of the heat storage reaction medium (for example, water) and expansion of the chemical heat storage material structure due to the combination (for example, hydration) of the heat storage reaction medium. This means that the chemical heat storage material structure is formed with a state that limits the volume change in a predetermined plane to the extent required to suppress the collapse of the chemical heat storage material structure. Specifically, a state in which the true density ratio of the chemical heat storage material structure is accommodated in the structure housing member in a range satisfying 45% or more and 63% or less is preferable.

<2> In the chemical heat storage device according to the first invention described in <1>, the chemical heat storage material absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction. It is preferable that

  When composed of such a hydration-reactive heat storage material, the volume expansion and contraction that occur during heat absorption and heat generation are large, and breakage and deformation such as cracks that easily occur due to this volume change, and the accompanying reactivity. Reduction can be effectively prevented.

<3> In the chemical heat storage device according to the first invention described in <1> or <2>, the chemical heat storage material is more preferably an alkaline earth metal hydroxide.

  Since alkaline earth metal hydroxide is used as the chemical heat storage material, the effect of the present invention is more effective due to the large volume change, as well as material stability against heat storage and heat dissipation reactions (hydration and dehydration). Is expensive. Therefore, a stable heat storage effect can be obtained over a long period of time.

<4> In the chemical heat storage device according to the first invention described in any one of the above items <1> to <3>, the chemical heat storage material structure is configured in a hexahedral structure, and at least one of the hexahedral structures is provided. The aspect which made the surface contact the inner wall of a structure accommodation member and restrained is preferable.

  Of the six surfaces of the chemical heat storage material structure, one surface or two or more surfaces are brought into contact with the inner wall surface of the housing member that houses the chemical heat storage material structure to regulate the space in which the chemical heat storage material can expand and contract. By setting it in a state, the particles inside the structure are maintained at an appropriate distance, and a significant volume change of the chemical heat storage material structure is limited. Thereby, the shear force between a chemical heat storage material structure and an inner wall is reduced, and collapse of the structure which is a molded object can be prevented.

<5> In the first invention according to any one of <1> to <4>, the true density ratio of the chemical heat storage material structure housed in the housing member is 45 to 63%. Some cases are preferred.

When the true density is within the above range, the chemical heat storage material exhibits a binding property between particles, and the distance between particles is kept at an appropriate distance. As a result, the binding reaction of the heat storage reaction medium (for example, water when a metal hydroxide such as Ca (OH) ₂ is used) proceeds well, and excessive deformation is suppressed during volume shrinkage during the dehydration reaction. The interface separation from the inner wall of the chemical heat storage material structure can be kept small.

<6> In the first invention described in the above <4> or <5>, the container having a six-sided wall and a six-sided inner wall as the structure housing member (for example, A hollow hexahedron having six walls), and at least one of the walls is a permeable wall through which a heat storage reaction medium passes, and at least one of the walls is a heat conductive heat transfer wall. .

Since at least one surface is a transmission wall through which a heat storage reaction medium (for example, water when a metal hydroxide such as Ca (OH) ₂ is used) passes, a reaction (for example, water) that suppresses the passage resistance of the heat storage reaction medium is small. Sum reaction), and it is possible to increase the efficiency and output of chemical heat storage. Moreover, since at least one surface is a heat transfer wall, heat exchange can be performed satisfactorily.

<7> The structure housing member in the first invention according to any one of <1> to <5> is a cylindrical body (for example, a cylindrical body having at least four walls) and the cylinder. A lid member that closes at least one of one end and the other end of the cylindrical body, and the chemical heat storage material structure can be attached to and detached from the cylindrical body.

  Since the structure housing member has a cylindrical body and a lid material separately, and is not configured as an integral structure, it is fixed by pressure due to expansion when attaching or detaching the chemical heat storage material structure Therefore, it is possible to avoid a state where the heat storage material cannot be detached because it is in a state, and the exchange efficiency of the heat storage material structure can be improved.

Moreover, the manufacturing method of the chemical heat storage device which is 2nd invention is as follows.
<8> A step of preparing a chemical heat storage material structure including a granular chemical heat storage material having an average primary particle diameter of d [μm], and at least one of the chemical heat storage material structures while accommodating the chemical heat storage material structure A surface treatment is applied to at least a part of the inner wall surface of the structure housing member that restrains a part, and the ten-point surface roughness Rz [μm] based on JIS B 0601 is smaller than the average primary particle diameter d on the inner wall surface. A step of forming a surface, and the chemical heat storage material structure is bound to the structure housing member having the inner wall surface, and at least a part of the chemical heat storage material structure is constrained on the surface where Rz is smaller than the average primary particle diameter d. And a step of accommodating the container so as to be accommodated.

In the second invention, with respect to the inner wall surface of the structure housing member that houses the chemical heat storage material structure and restrains at least a part thereof, a part or the entire surface of the inner wall surface is Rz (compliant with JIS B 0601). By applying surface treatment so that the ten-point surface roughness (μm) is smaller than the average primary particle diameter d of the chemical heat storage material particles, the chemical heat storage material can prevent volume changes due to significant expansion and contraction during the reaction. Therefore, even when the structure is constrained by a wall or the like, the particles of the chemical heat storage material are prevented from entering and fixing into the concave gap on the wall surface.
As a result, when the chemical heat storage material structure is housed in the structure housing member, the shear between the wall or the like and the chemical heat storage material is suppressed to a small level, and damage to the chemical heat storage material caused by the influence of shear stress is prevented. As a result, the durability of the chemical heat storage material is improved. In addition, the chemical heat storage material is not easily broken when it is attached / detached (exchanged), and the attachment / detachment / exchangeability is improved.

<9> In the method for manufacturing a chemical regenerator according to the second invention described in <8>, as the surface treatment applied to at least a part of the inner wall surface of the structure housing member that houses the chemical heat storage material structure, A preferable aspect is (1) polishing by lapping, (2) plating, (3) resin coating, or (4) a process of attaching any one selected from a polyimide material, a fluororesin material, and a nonwoven fabric. As the polyimide material and the fluororesin material, for example, a polyimide film, a polyimide sheet, a fluororesin film, a fluororesin sheet, or the like can be used.

  Among the above, (1) polishing by lapping or (2) surface treatment by plating treatment can ensure a desired heat-resistant temperature and may be exposed to a relatively high temperature exceeding 300 ° C. It is suitable as a surface treatment method at certain times. In addition, (3) Resin coating treatment or (4) Polyimide material, fluorine resin material, or non-woven fabric sticking treatment is simpler at a lower cost when it is assumed to be used at a relatively low temperature of 300 ° C or lower. The desired slipperiness can be obtained.

  According to the present invention, the chemical heat storage material is restrained by restricting the volume change by restraining the chemical heat storage material, and the sticking of the restrained chemical heat storage material structure to the wall or the like of the housing member is prevented, and the shear damage is suppressed. And a manufacturing method thereof.

It is a perspective view which shows the chemical heat storage device which concerns on embodiment of this invention. It is an exploded view which decomposes | disassembles and shows the structure of the chemical heat storage device shown in FIG. It is a photograph which shows the state which has arrange | positioned the 2 L-shaped jig | tool for restraining a molded object at intervals. (A) is a photograph showing a state in which the chemical heat storage material is damaged when the structure is taken out and is fixed to the jig, and (B) is a state in which the chemical heat storage material structure is cracked. It is a photograph shown.

Hereinafter, embodiments of the chemical heat storage device of the present invention will be described in detail with reference to the drawings, and embodiments of the method for manufacturing the chemical heat storage device of the present invention will be described in detail through the description. In addition, in the following embodiment, it demonstrates centering on the form using calcium hydroxide (Ca (OH) ₂ ) which is a hydroxide of an alkaline-earth metal as a chemical heat storage material. However, the present invention is not limited to the following embodiments.

DESCRIPTION OF EMBODIMENTS Embodiments relating to a chemical heat storage device and a method for producing the same according to the present invention will be described with reference to FIGS. In the present embodiment, a granular material of Ca (OH) ₂ is used as a chemical heat storage material, and the chemical heat storage material structure formed into a hexahedron rectangular parallelepiped has six walls, of which two wide walls are moisture. It is formed of a non-woven fabric (permeation wall) that passes through the (heat storage reaction medium), and the other four side walls are housed in a hexahedral container formed of a heat conductive stainless steel plate (heat transfer wall). All are constrained by six walls.

As shown in FIGS. 1 to 2, the chemical heat accumulator 100 according to the present embodiment includes two narrow-width long stainless steel materials 11, two narrow-width short-length stainless steel materials 13, and a stainless steel frame material ( A structure restraining container (structure housing member) 30 formed in an internal hollow hexahedron structure using two moisture permeable walls 15 formed by attaching a nonwoven fabric to an unillustrated), and housed in this structure restraining container , And a Ca (OH) ₂ structure 21 of a rectangular parallelepiped formed by press molding of Ca (OH) ₂ powder.

As shown in FIGS. 1 to 2, the structure-constraint container 30 includes four heat transfer walls that form an endless frame structure with the stainless steel material 11 and the stainless steel material 13, and a stainless steel frame material (not shown). It is formed with two moisture permeable walls (permeable walls) 15 to which a nonwoven fabric is attached. The four heat transfer walls are provided as side walls having thermal conductivity in a connected state. The six surfaces of the Ca (OH) ₂ structure 21 are in contact with at least the inner walls of the six surfaces of the structure restraining container 30. When the Ca (OH) ₂ structure 21 expands due to a hydration reaction, the outer shape of the structure is restricted by the inner wall and the shape is maintained, and the close contact with the inner wall is increased, and heat can be radiated to the outside through the heat transfer wall. It is like that. Further, the volume expansion during the hydration reaction is absorbed in a slight gap between the Ca (OH) ₂ structure and each inner wall and a space corresponding to the pore volume in the structure. On the contrary, when the Ca (OH) ₂ structure 21 contracts due to the dehydration reaction, the contraction of the structure is restricted due to the close contact with the inner wall, and the shape is maintained.

The moisture permeable wall 15 is a non-woven fabric produced using chemical fibers, and is joined to the stainless steel material 11 and the stainless steel material 13 at the frame material portion. By providing the moisture permeable wall 15, it is possible to transfer moisture generated during the hydration reaction or dehydration reaction in the Ca (OH) ₂ structure 21 accommodated in the structure restraining container 30. ing.

  For the moisture permeable wall 15, a plate-like material having holes that allow moisture to permeate can be used without limitation. For example, a mesh material made of stainless steel (for example, SUS316L) may be used. Moreover, it is not restricted to a mesh-like thing, The thing which selected the other shape arbitrarily and provided the hole can be used. For example, a plurality of circular holes may be provided at predetermined intervals.

Moreover, as a material of a moisture permeation | transmission wall, what is necessary is just to be able to follow or restrict | limit expansion / contraction of a chemical heat storage material structure (Ca (OH) ₂ structure in this embodiment). In the present embodiment, water) which is difficult to cause deterioration such as corrosion, softening and rust is preferable. Specifically, a metal material such as a stainless steel material or an aluminum material, a resin material, or the like may be used.

  The stainless steel material 11 and the stainless steel material 13 are preferably made of a material that is unlikely to cause deterioration such as corrosion, softening, rust and the like with a heat storage and heat dissipation reaction medium (water in the present embodiment) and can impart thermal conductivity. For example, metal materials, such as stainless steel material and aluminum material, are mentioned.

The hollow interior of the structure-constrained container 30 is formed in a size of 50 mm × 30 mm × 3 mm with six inner walls, and the inner dimension of the hollow portion is approximately the size of the Ca (OH) ₂ structure 21 as described later. It is the same size.

The size of the hollow interior can be arbitrarily selected according to the purpose, the type of chemical heat storage material structure (Ca (OH) ₂ structure in this embodiment) (ie, expansion / contraction rate), and volume. it can.

Heat resistant polyimide film (Kapton (registered trademark) H type, manufactured by Toray DuPont Co., Ltd.) is affixed to the four inner walls formed of stainless steel material 11 and stainless steel material 13 among the six inner walls. The ten-point surface roughness (Rz) is adjusted to be smaller than the average particle size (average primary particle size d) of the primary particles of Ca (OH) ₂ powder of the Ca (OH) ₂ structure 21 accommodated therein. Has been. When Rz becomes larger than the average primary particle diameter d of the Ca (OH) ₂ powder, Ca (OH) ₂ particles enter the concave gaps existing on the wall and are easily fixed. Therefore, by satisfying the relationship of Rz <average primary particle diameter d, slipperiness capable of moving the wall surface even when the volume of the Ca (OH) ₂ structure 21 is changed is obtained, and the Ca (OH) ₂ structure 21 is When the structure is constrained by the inner wall surface, shearing between the inner wall surface and the Ca (OH) ₂ structure is suppressed, and damage to the structure caused by the influence of the shearing force is prevented. Thereby, durability of a chemical heat storage material improves. In addition, when the chemical heat storage material structure 21 is attached / detached (exchanged), the chemical heat storage material structure 21 is less likely to be broken, and can be easily attached and detached.

As the surface treatment satisfying the relationship of Rz <average primary particle diameter d, a polyimide sheet may be used in addition to the polyimide film. Examples of the surface treatment method include a method of attaching a fluororesin material such as a fluororesin film or sheet such as Teflon (registered trademark) or graphite Teflon (registered trademark), or a non-woven fabric. In addition to the method of applying a sticking process, polishing by lapping, plating, resin coating, and the like can be given.
The lapping process is performed by rotating the lapping plate between the lapping surface plate and the workpiece (in this embodiment, the structure-constrained container 30) while rubbing both of them together with a diamond abrasive and a polishing liquid to remove ultrafine particles. This is a polishing method to be performed.
The plating treatment is a surface treatment method in which the surface forming the inner wall surface of the structure-constraint container 30 is covered with a metal thin film by a method such as electroplating or electroless plating.
The resin coating treatment is a method of coating a coating solution in which a resin is dissolved or dispersed in a solvent. There is no restriction | limiting in particular in resin used here, According to Rz desired, it can select suitably.

  As long as Rz satisfies the relationship smaller than the average primary particle diameter d of the chemical heat storage material, the range of the average primary particle diameter d and Rz is not particularly limited, but the range of Rz is 1.5 μm or less in terms of desorption. Is preferable, and the range of 1 μm or less is more preferable.

  Here, the ten-point surface roughness (Rz) is a value measured according to JIS B 0601 (1994).

The structure restraining container 30 in the present embodiment accommodates the Ca (OH) ₂ structure 21 and restrains the entire six surfaces thereof, thereby absorbing heat accompanying the dehydration reaction and accompanying the hydration reaction. Therefore, no significant volume expansion or contraction occurs during heat dissipation.

And Ca _{(OH) 2} structure 21 is constrained, significant expansion in the use or the like of the Ca _{(OH) 2} structure 21, meaning to limit the shrinkage. For this embodiment, the shrinkage of the Ca (OH) ₂ structure 21 when the (binding of the heat storage reaction medium) the hydration reaction is Ca (OH) ₂ structure when the (elimination of the heat storage reaction medium) dehydration reaction The difference from the expansion of the body 21 is such that the wall of the structure restraining container 30 comes into contact with the Ca (OH) ₂ structure 21 to such an extent that the collapse of the Ca (OH) ₂ structure 21 is suppressed. It means that a small restricted state is formed.

-Chemical heat storage material-
The Ca (OH) ₂ structure 21 is a molded body having a true density ratio of 57% obtained by press-molding Ca (OH) ₂ granules (average primary particle diameter of 6 to 8 μm), which is a chemical heat storage material. A chemical heat storage material is a substance that can absorb and release heat using a chemical reaction, and is present as a powder in the structure. The chemical heat storage material being granular or granular means a state of powder containing particles.

Examples of the chemical heat storage material include calcium hydroxide (Ca (OH) ₂ ), magnesium hydroxide (Mg (OH) ₂ ), barium hydroxide (Ba (OH) ₂ ), and hydrates thereof (Ba ( Inorganic hydroxides of alkaline earth metals such as (OH) ₂ · H ₂ O), inorganic hydroxides of alkali metals such as lithium hydroxide monohydrate (LiOH · H ₂ O), aluminum oxide trihydrate Inorganic oxides such as a product (Al ₂ O ₃ .3H ₂ O) can be given. Among them, a hydration reactive heat storage material that absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction is preferable, and calcium hydroxide (Ca (OH) ₂ ) is particularly preferable.

Here, heat storage and heat dissipation will be described using calcium hydroxide (Ca (OH) ₂ ) as an example.
Ca (OH) ₂ , which is a chemical heat storage material, stores heat (absorbs heat) as it dehydrates, and dissipates heat (generates heat) as it hydrates (restores to calcium hydroxide). That is, Ca (OH) ₂ can reversibly repeat heat storage and heat dissipation by the reactions shown below.
Ca (OH) ₂ Ｃａ CaO + H ₂ O
In addition, when the heat storage amount and the heat generation amount Q are also shown, this is as follows.
Ca (OH) ₂ + Q → CaO + H ₂ O
CaO + H ₂ O → Ca (OH) ₂ + Q

  As an average particle diameter of a granular chemical heat storage material, 50 micrometers or less are preferable at an average primary particle diameter (d). When the average primary particle diameter d of the chemical heat storage material present in the molded body is 50 μm or less, it is preferable in terms of moldability, and when a clay mineral is used in combination, a reaction product between the clay mineral and the clay mineral is present. And a stronger porous structure is obtained. Among these, the average primary particle diameter is more preferably 30 μm or less, and further preferably 10 μm or less. Further, the lower limit of the average primary particle size is desirably 0.1 μm.

  In the present invention, it is configured in a range satisfying the relationship of “ten-point surface roughness (Rz) <average primary particle diameter d of chemical heat storage material”, and in particular, the chemical heat storage material structure is more effectively prevented from sticking. From the viewpoint of further avoiding the destruction of the chemical heat storage material structure caused by the shear effect accompanying the volume change, the difference between the average primary particle diameter d and Rz of the chemical heat storage material (= d−Rz; μm) is: It is preferably 1.5 μm or less, and more preferably 1 μm or less.

  The average primary particle diameter d of the chemical heat storage material is a value measured by a laser diffraction / scattering method using a laser diffraction / scattering particle size distribution analyzer SALD-2000A (manufactured by Shimadzu Corporation).

The true density ratio of the Ca (OH) ₂ structure 21 is 57%, but the true density ratio of the chemical heat storage material structure is preferably adjusted to a range of 45 to 63%. The true density ratio indicates how much the substantial component ratio of the structure excluding the pores is, and the smaller the pores, the higher the true density ratio. When the true density ratio is in the range of 45 to 63%, the chemical heat storage material has a binding property between particles, and the distance between the particles is kept at an appropriate distance. Specifically, if the true density is 45% or more, the volume change can be suppressed to such an extent that the structure does not collapse, and if the true density is 63% or less, the allowable volume that can be deposited and expanded is sufficient. Secured and good reactivity is obtained.
As a result, the hydration reaction (binding reaction of the heat storage reaction medium) in the Ca (OH) ₂ structure 21 proceeds well, and excessive deformation is suppressed during volume shrinkage during the dehydration reaction, and Ca (OH) The interface separation from the inner wall of the _two structures 21 can be kept small.
The true density ratio of the chemical heat storage material structure in the present invention is more preferably in the range of 51 to 60%, and particularly preferably in the range of 55 to 59%.

The true density ratio is a value calculated from the following equation based on a measured value obtained by measuring the mass [g] and the volume [ml] of the chemical heat storage material structure.
True density ratio [%] = (mass / volume) / true density × 100

In addition, the Ca (OH) ₂ structure 21 is formed in a size of 50 mm × 30 mm × 3 mm, and is formed in the same size as the inner size of the structure-constraint container 30 so that a restrained state is formed. The distance between the particles of the heat storage material powder during molding can be kept substantially constant. Thereby, generation | occurrence | production of the internal crack accompanying the volume expansion / contraction of the Ca (OH) ₂ structure 21 is suppressed, and the generated internal crack can be self-repaired. In addition, an effect of suppressing external defects by suppressing deformation such as bending and warping on the outer shape can be expected, and an effect that the defects at the time of contraction can be self-repaired at the time of expansion is obtained.

From such a viewpoint, it is preferable that the chemical heat storage material structure has an outer dimension after press molding within a range that can be regarded as equivalent to or equivalent to the inner dimension of the structure housing member. Moreover, the external shape after press molding of the chemical heat storage material structure may be in an aspect similar to the shape of the hollow inside of the structure-constrained container. A mode in which the similarity ratio between each surface of the chemical heat storage material structure after desorption and each surface of the hollow portion of the structure restraining member is equal is preferable. If the similarity ratios are equal to each other, the chemical heat storage material structure is accommodated, and when the chemical heat storage material structure is expanded and contracted during use, good adhesion to the inner wall surface of the hollow portion of the structure restraining container is obtained. can get. The similarity ratio means that the ratio of each side is the same between the shapes to be compared. For example, in the case of a hexahedron, the ratio of each side in the three-axis direction of the three-dimensional coordinate axis (XYZ axis) is equal. In this case, when the chemical heat storage material structure is swollen or contracted, each surface is evenly restrained in the structure restraining container 30. In addition, for the same reason as described above, an alkaline earth metal hydroxide chemical heat storage material structure such as a Ca (OH) ₂ structure is used, and it is filled in a range of true density ratio of 55 to 59%. Are preferred.

  The content ratio of the chemical heat storage material in the chemical heat storage material structure is preferably 20 to 80% by volume (20 to 80% by mass with respect to the total mass of the structure) in terms of volume ratio, 30 -70 volume% (30-70 mass% with respect to the structure total mass) is more preferable. When the content of the chemical heat storage material is 20% by volume or more or 20% by mass or more, the heat absorption and heat generation amount can be kept high, and when it is 80% by volume or less or 80% by mass or less, the structure having higher structural strength. The body is obtained.

-Organic binder-
The chemical heat storage material structure (Ca (OH) ₂ structure 21 in this embodiment) may be molded using an organic binder together with the granular chemical heat storage material (Ca (OH) _{2 in} this embodiment).

  Since the granular chemical heat storage material generally has poor adhesion between particles and is difficult to mold, an organic binder may be used in combination for imparting structure formability (binding component). Moreover, crystal control and porosity can be improved by using an organic binder in combination.

  Examples of the organic binder include various modified or unmodified polyvinyl alcohols (PVA), cellulose resins such as carboxymethyl cellulose, urethane resins such as aqueous urethane, resin components such as starch, and solvents such as diethylene glycol (DEG) and ethanol. Components, etc. can be suitably used.

-Clay minerals-
The chemical heat storage material structure (Ca (OH) ₂ structure 21 in the present embodiment) may be formed by using a granular chemical heat storage material (and the organic binder as necessary) and further using a clay mineral. Good. In this case, a structure in which clay minerals intervene between the powders of the chemical heat storage material is obtained, and the clay mineral has a porous skeleton structure, in which the powder of the chemical heat storage material is dispersed and held. May be. In the structure, the powder of the chemical heat storage material is held in a dispersed state and is excellent in water vapor diffusibility due to the porosity, so that the above reaction is likely to occur in many powders.

The chemical heat storage material structure (Ca (OH) ₂ structure 21 in this embodiment) preferably contains at least one clay mineral having a layered ribbon structure. Clay minerals with a layered ribbon structure are clay minerals (layered silicate minerals) in which a plurality of single chains resembling pyroxene are combined to form a tetrahedral ribbon, giving viscosity to chemical heat storage materials and having a porous structure And the structural strength of the structure can be kept high. Moreover, the diffusibility of water vapor | steam can also be provided.

Examples of the clay mineral include sepiolite [hydrated magnesium silicate represented by Mg ₈ Si ₁₂ O ₃₀ (OH) _4. (OH ₂ ) ₄ .8H ₂ O], attapulgite [palygorskite; = (Mg · AL) ₂ Hydrous magnesium silicate having a palygorskite structure represented by Si ₄ O ₁₀ (OH) · 4H ₂ O, wire diameter of 5 μm or less, kaolinite [kaolin; = Al ₂ (Si ₂ O ₅ ) (OH) ₄ Aluminum silicate, wire diameter of 1 μm or less], and the like, and one or more of these can be used in combination. As the clay mineral, a commercially available product may be used. As an example of a commercially available product, Turkish sepiolite manufactured by Omi Mining Co., Ltd. can be used.

A clay mineral having a layered ribbon structure has an advantage of less sintering (aggregation) compared to the following bentonite which does not belong to this. In particular, sepiolite is sintered at a temperature close to the dehydration temperature of the chemical heat storage material, and there is an advantage that the specific surface area is less reduced by sintering at that temperature.
The clay mineral may be appropriately selected according to the application and the like in consideration of such advantages.

In addition, the chemical heat storage material structure (Ca (OH) ₂ structure 21 in the present embodiment) may include bentonite that does not belong to the clay mineral having a layer ribbon structure, or may mix clay mineral and bentonite. . Bentonite is a clay mineral having a stronger adhesive force than a clay mineral having a layered ribbon structure, and can obtain a strong porous structure alone (in a state where it is not mixed with the clay mineral). Further, for example, it contributes to improving the bonding strength to the metal wall, and a porous structure in which pores are formed between the powders of the chemical heat storage material can be obtained even with a composition using bentonite.
In this invention, the structure which mixes the clay mineral which mixed the clay mineral and bentonite of a layer ribbon structure with a granular chemical heat storage material may be sufficient. In this case, the ratio of bentonite is preferably 10 to 40% by mass with respect to the clay mineral having a layer ribbon structure.

The content of the clay mineral in the chemical heat storage material structure (Ca (OH) ₂ structure 21 in this embodiment) is preferably in the range of 10 to 40% by mass with respect to the total mass of the structure, and 25 to 35. A range of mass% is more preferred. When the content of the clay mineral is 10 mass or more, higher structural strength is easily obtained, and when it is 40 mass% or less, a higher endothermic heat generation amount is easily obtained.

-Other ingredients-
The chemical heat storage material structure (Ca (OH) ₂ structure 21 in the present embodiment) may contain other components such as inevitable impurities and additives in addition to the components described above.

Next, the manufacturing method of the chemical heat storage device 100 which concerns on this embodiment is demonstrated.
In producing the chemical heat storage device 100 according to the present embodiment, first, Ca (OH) ₂ is used as a granular chemical heat storage material having an average primary particle diameter of d μm, press-molded, and 50 mm × 30 mm × 3 mm as shown in FIG. A rectangular parallelepiped Ca (OH) ₂ structure (chemical heat storage material structure) 21 is prepared (hereinafter, this process is also referred to as “structure preparation process”). What is necessary is just to select the molding conditions at the time of press molding suitably according to shapes, such as a composition, a property, and thickness of a chemical heat storage material.

In the structure preparation step in the present embodiment, a molded body is formed by press-molding Ca (OH) ₂ powder, but it is not always necessary to prepare by performing press-molding, and commercially available Ca (OH) ₂ is molded. The body may be used. The forming process is not limited to press forming, and may be performed using other forming methods.

As shown in FIG. 2, a cylindrical structure restraining container (structure housing member) 30 having a rectangular cross section of 50 mm × 30 mm × 3 mm is prepared, and a heat-resistant polyimide film (Kapton (registered trademark)) is formed on the entire inner wall surface. Surface treatment is performed by attaching H type (Toray DuPont Co., Ltd.) (hereinafter, this step is also referred to as “surface treatment step”). The details of the surface treatment are as described above. Thereby, 10-point surface roughness (Rz) based on JIS B 0601 is made smaller than the average primary particle diameter d of Ca (OH) ₂ powder of Ca (OH) ₂ structure 21 accommodated inside. Can be adjusted.

Then, the obtained Ca (OH) ₂ structure 21 is inserted from one end of the structure restraining container 30 that is opened, and the one end and the other end of the structure restraining container 30 that are opened are closed with the lid member 13 (hereinafter referred to as the lid 13). This process is also referred to as a “structure housing process”). At this time, the average primary particle diameter d of the Ca (OH) ₂ particles of the Ca (OH) ₂ structure 21 is larger than Rz of the inner wall surface (kapton attachment surface) subjected to the surface treatment of the structure restraining container 30. .

As shown in FIGS. 1 to 2, the structure-constrained container 30 is made of a non-woven fabric on four heat transfer walls that form an endless shape with the stainless steel material 11 and the stainless steel material 13, and a stainless steel frame material (not shown). It is formed by two moisture permeable walls (permeation walls) 15 attached. At this time, the six surfaces of the Ca (OH) ₂ structure 21 are not in close contact with the inner walls of the six surfaces of the structure-constraint container 30 but are in contact with each other. When the Ca (OH) ₂ structure 21 expands due to a hydration reaction, the outer shape of the structure is restricted by the inner wall, and the shape is maintained. It can dissipate heat. Further, the volume expansion during the hydration reaction is absorbed in a slight gap between the Ca (OH) ₂ structure and each inner wall and a space corresponding to the pore volume in the structure.

As described above, the “Rz <Ca (OH) ₂ structure 21 average primary particle diameter d” of the structure restraining container 30 is applied to the six surfaces of the Ca (OH) ₂ structure 21 that is the chemical heat storage material structure. A chemical heat accumulator restrained by the six inner walls satisfying the above relationship is produced.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1
A white powder (JIS R 9001 grade: special name) of calcium hydroxide (Ca (OH) ₂ ) having an average primary particle size of 0.8 μm is prepared as a chemical heat storage material, and the white powder is used as an organic binder. For producing a heat storage material structure by mixing polyvinyl alcohol (PVA) in an amount of 1% by mass with respect to the total amount of powder and ion-exchanged water, and granulating using spray drying. A precursor composition was prepared.
The average primary particle diameter is a value measured by a laser diffraction / scattering method using a laser diffraction / scattering particle size distribution analyzer SALD-2000A (manufactured by Shimadzu Corporation).

  The obtained precursor composition was molded by a press molding method to obtain a molded body having a size of 50 mm long × 30 mm wide × 3 mm thick. The true density ratio of the obtained molded body was 57%.

Next, this molded body was subjected to heat treatment (baking) at 700 ° C. for 60 minutes to dehydrate Ca (OH) ₂ in the precursor composition and remove PVA, and at the same time, carbon dioxide in the atmosphere. Calcium was decomposed and decarboxylated.

Next, the molded body after the heat treatment as described above was set in a predetermined jig capable of supporting and restraining the six surfaces.
Specifically, a non-woven fabric made of chemical fiber is attached to one surface of a stainless steel plate, and two stainless steel L-shaped jigs are placed on the non-woven fabric so that the long side and the short side face each other. Arranged as shown in FIG. 3, the above-described molded body was set inside (50 mm × 30 mm × 3 mm) surrounded by an L-shaped jig. Subsequently, another stainless steel plate with a nonwoven fabric attached on one side was prepared, and the stainless steel plate with the nonwoven fabric was superposed on the molded body so that the nonwoven fabric surface was in contact with the molded body. In this way, the two flat surfaces of the molded body were supported and restrained by the gas permeable permeation wall made of nonwoven fabric, and the four side surfaces were supported and restrained by the L-shaped jig. .

At this time, each surface of the two L-shaped jigs facing the region surrounded by them, that is, each surface in contact with the four side surfaces of the molded body, is a heat-resistant polyimide film (Kapton (registered trademark) H type, The ten-point surface roughness (Rz) is adjusted to 0.2 μm by pasting Toray DuPont Co., Ltd. The Rz on the surface of the nonwoven fabric (transmission wall) is 1 μm.
The ten-point surface roughness (Rz) is a value measured according to JIS B 0601 (1994).

  As described above, the molded body was held for 30 minutes at 200 ° C. in a state of covering the six surfaces of the molded body to cause a hydration reaction. Then, it heated again, heated up to 500 degreeC, hold | maintained for 15 minutes (dehydration and baking), and then fell and hold | maintained (hydrated) at 200 degreeC. Thus, the operation of raising and lowering the temperature and firing and hydrating were repeated four times.

  After the completion of the firing and hydration reactions, the molded body was taken out with the nonwoven fabric attached to obtain a chemical heat storage structure. At this time, the side of the molded body (chemical heat storage structure) was not fixed to the L-shaped jig (Kapton surface), and it was possible to remove it in a clean rectangular state without any peeling or cracking. .

As shown in FIG. 2, the removed chemical heat storage structure is inserted into a 50 mm × 30 mm × 3 mm cylinder having a rectangular cross section formed of stainless steel (SUS316L), and the cylinder in the insertion direction is inserted. The bottom part and the top part were closed with a cover material made of SUS316L to produce a chemical heat accumulator. Here, the four inner walls of the cylindrical body and the inner wall of the lid material are attached with a heat-resistant polyimide film (Kapton (registered trademark) H type, manufactured by Toray DuPont Co., Ltd.), and Rz = It is adjusted to 0.2 μm.
As a result, the chemical heat storage structure is supported on all six surfaces in contact with the metal wall, thereby preventing collapse associated with expansion during the reaction, etc. The sticking is suppressed and the occurrence of peeling or cracking is prevented.

(Example 2)
In Example 1, the polyimide film (Kapton H type) affixed to each surface of the two L-shaped jigs in contact with the four side surfaces of the molded body was changed to a Teflon (registered trademark) tape, and Rz was set to 0.00. A chemical heat storage structure and a chemical heat storage were produced in the same manner as in Example 1 except that the thickness was adjusted to 7 μm. The results are shown in Table 1 below.

(Example 3)
In Example 1, PVA (1% by mass with respect to the total amount with white powder) was added to Miracle (registered trademark) P series Turkish sepiolite powder P-300 (MgSi ₁₂ O ₃₀ (OH) manufactured by Omi Mining Co., Ltd. _{) 4 (OH 2) 4 ·} 8H 2 O; except for instead of 1% by mass) with respect to the total amount of the white powder in the same manner as in example 1, producing a chemical heat storage structure and chemical heat accumulator did. The results are shown in Table 1 below.

(Comparative Examples 1-3)
In Example 1, the process of sticking a polyimide film (Kapton H type) to each surface of the two L-shaped jigs in contact with the four side surfaces of the molded body was changed to the process shown in Table 1 below. A chemical heat storage structure and a chemical heat storage were produced in the same manner as in Example 1 except that Rz was adjusted.
In Comparative Example 1, an L-shaped jig obtained by wire cutting was used.

  As shown in Table 1, in Examples 2 to 3, as in Example 1, when the molded body was taken out to obtain the chemical heat storage structure, the L-shaped jig on the side of the molded body (chemical heat storage structure) was used. There was no sticking to the tool (Kapton surface), and it could be removed in a clean rectangular state without peeling or cracking. Therefore, when a chemical heat storage device is produced using the obtained chemical heat storage structure, all six surfaces are constrained in contact with the metal wall, thereby preventing collapse associated with expansion during reaction, etc. When taking out from the shaped body, sticking to the inner wall surface was suppressed, and the occurrence of peeling or cracking could be prevented.

  Moreover, in Comparative Examples 1-3, as shown in the said Table 1, since the surface roughness represented by Rz of an inner wall is larger than the average primary particle diameter of the used chemical heat storage material, when hydrated, As shown in FIG. 4 (A), the heat storage material particles enter into the concave gaps and adhere to the jig when removed, and the comparative example 1 shows that FIG. 4 (B). Cracks occurred as in

  In the above-described embodiments and examples, the description is centered on the method of sticking a polyimide film as a surface treatment, but the method of sticking a fluorine resin material or a non-woven fabric other than the polyimide material similarly prevents the occurrence of sticking and shearing. Good results are obtained for breakage. Further, in addition to the method of attaching as a surface treatment, the occurrence of sticking is similarly prevented when a lapping process, a polishing process, a plating process, or a resin coating process is performed. .

11, 13 ... Heat transfer wall 15 ... Transmission wall 21 ... Ca (OH) ₂ structure (chemical heat storage material structure)
23 ... Polyimide film (Polyimide material)
30 ... Structure restraint container (structure housing member)

Claims (10)

A chemical heat storage material structure including a granular chemical heat storage material having an average primary particle diameter of d [μm];
Ten-point surface roughness Rz [μm based on JIS B 0601 of the inner wall surface that accommodates the chemical heat storage material structure and restrains at least a part of the chemical heat storage material structure and is in contact with the chemical heat storage material structure ] A structure housing member smaller than the average primary particle diameter d,
Chemical regenerator with   The chemical heat storage material according to claim 1, wherein the chemical heat storage material is a hydration reactive heat storage material that absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction.   The chemical heat storage material according to claim 1, wherein the chemical heat storage material is an alkaline earth metal hydroxide.   The chemical heat storage material structure has a hexahedral structure, and at least one surface of the hexahedral structure is constrained in contact with an inner wall of the structure housing member. The chemical regenerator described in 1.   The chemical heat storage device according to any one of claims 1 to 4, wherein the chemical heat storage material structure has a true density ratio of 45 to 63%.   The structure housing member has six walls, at least one of the walls is a transmission wall through which a heat storage reaction medium passes, and at least one of the walls is a heat conductive heat transfer wall. Item 6. The chemical heat accumulator according to item 4 or item 5.   The structure housing member includes a cylindrical body and a lid member that closes at least one of one end and the other end of the cylindrical body, and the chemical heat storage material structure can be attached to and detached from the cylindrical body. The chemical heat accumulator according to any one of claims 1 to 6, which is configured. Preparing a chemical heat storage material structure including a granular chemical heat storage material having an average primary particle diameter of d [μm];
Surface treatment is applied to at least a part of the inner wall surface of the structure housing member that houses the chemical heat storage material structure and restrains at least a part of the chemical heat storage material structure, and conforms to JIS B 0601 on the inner wall surface. Forming a surface having a ten-point surface roughness Rz [μm] smaller than the average primary particle diameter d;
Storing the chemical heat storage material structure in the structure housing member having the inner wall surface such that at least a part of the chemical heat storage material structure is constrained on the surface where Rz is smaller than the average primary particle diameter d; ,
A method for manufacturing a chemical regenerator.   The method for manufacturing a chemical regenerator according to claim 8, wherein as the surface treatment, at least a part of the inner wall surface is subjected to any treatment selected from polishing by lapping, plating treatment, and resin coating treatment.   The method for producing a chemical regenerator according to claim 8, wherein as the surface treatment, a process of attaching any one selected from a polyimide material, a fluorine resin material, and a nonwoven fabric to at least a part of the inner wall surface is performed.