WO2023053859A1 - Heat storage structure and heat storage system - Google Patents

Abstract

Provided is a heat storage structure with which it is possible to prevent outflow of a chemical heat storage material due to the chemical heat storage material being flushed away or blown away by a reaction medium, and with which heat storage or an exothermic reaction can be stably carried out. This heat storage structure has a sealed container and a chemical heat storage material sealed in the sealed container, and is characterized in that: the sealed container includes a water vapor-permeable member in at least a part thereof; the chemical heat storage material contains magnesium oxide, magnesium hydroxide and at least one type of substance selected from the group consisting of at least a halide, an organic salt, or an inorganic salt selected from the group consisting of an alkali metal, an alkaline earth metal, aluminum, manganese, iron, nickel, copper, zinc and lead; this substance generates heat through a hydration reaction and/or stores heat through a dehydration reaction; and the moisture permeability of the water vapor-permeable member is 200-10,000 g/(m²·24h).

Description

Thermal storage structure and thermal storage system

The present disclosure relates to heat storage structures and heat storage systems.

　There is a demand for resource saving and energy saving as a countermeasure against global warming, and in recent years, the development and introduction of unused heat utilization technology focusing on the waste heat (exhaust gas heat quantity) emitted from factories has become active. As one of the unused heat utilization technologies, heat storage technology is expected to contribute greatly to the effective use of energy because it can store unused heat and select the time and place where heat is required. ing.

There are generally three types of heat storage technology: sensible heat storage that uses the specific heat of substances, latent heat storage that uses changes in the state of substances, and chemical heat storage that uses chemical changes in substances. Among them, in chemical heat storage, the heat storage material reacts with a specific reaction medium such as water or ammonia to generate heat. Chemical heat storage is suitable for long-term heat storage because it can maintain a heat storage state (a state where heat can be generated if there is a reaction medium) unless a reaction medium is supplied.

JP 2007-302844 A

Chemical heat storage must create a stable mechanism for heat storage and heat generation after considering a series of phenomena accompanying chemical reactions, and has various problems. For example, when an exothermic reaction is caused by a reaction medium, the particles of the heat storage material agglomerate in an attempt to reduce the surface energy of each particle of the heat storage material. There was a problem.
In order to address the above problem, in Patent Document 1, the heat storage material is covered with a second compound having pores through which water molecules can pass, thereby suppressing the aggregation of the heat storage material and reducing the decrease in reactivity. A heat-absorbing and heat-absorbing material is disclosed.

However, in the solution described in Patent Document 1, the heat storage material is an aggregate of fine particles, so if the reaction medium is liquid, there is a risk that it will be washed away. Also, if the reaction medium is a gas, the heat storage material tends to dance and may be blown away. Thus, the heat storage material may be washed away by the reaction medium. In addition, in the step of covering the heat storage material with the second compound, it is necessary to adjust the materials used and the process, and a simpler method is desired.

The present disclosure provides a heat storage structure that prevents the outflow of the chemical heat storage material due to the chemical heat storage material being swept away or blown away by the reaction medium, and capable of stably storing heat or exothermic reaction.

The present disclosure is a heat storage structure having a sealed container and a chemical heat storage material sealed in the sealed container,
The sealed container includes at least a portion of a water vapor permeable member,
The chemical heat storage material is
A group consisting of magnesium oxide, magnesium hydroxide, and at least one inorganic salt, organic salt and halide selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead. including at least one selected from
The chemical heat storage material is a substance that generates heat by a hydration reaction and/or stores heat by a dehydration reaction,
The heat storage structure is characterized in that the moisture permeability of the water vapor permeable member is 200 to 10000 g/(m ² ·24 h).

Further, the present disclosure is a heat storage system comprising a steam supplier for performing a hydration reaction, a heat supplier for performing a dehydration reaction, and a heat accumulator,
wherein the heat storage device comprises the heat storage structure of the present disclosure;
heat is sent to the heat accumulator by the heat supplier;
The chemical heat storage material contained in the heat storage structure undergoes a dehydration reaction with the heat sent to the heat accumulator, whereby heat is stored in the chemical heat storage material,
Further, steam is sent to the heat accumulator by the steam supplier,
The heat stored in the chemical heat storage material is extracted by a hydration reaction of the chemical heat storage material contained in the heat storage structure.
It relates to a heat storage system.

According to the present disclosure, it is possible to provide a heat storage structure that can prevent the chemical heat storage material from flowing out due to the reaction medium and stably store heat or generate heat.

Schematic diagram showing the configuration in one embodiment of the heat storage structure Schematic diagram showing the configuration in one embodiment of the heat storage structure Schematic diagram showing the configuration in one embodiment of the heat storage system

Hereinafter, embodiments of a heat storage structure and a heat storage system according to the present disclosure will be described with reference to preferred embodiments. Moreover, the present disclosure is not limited to the following embodiments.
Further, in the present disclosure, unless otherwise specified, the descriptions of “X or more and Y or less” or “X to Y” representing a numerical range mean a numerical range including the lower limit and the upper limit, which are endpoints. When numerical ranges are stated stepwise, the upper and lower limits of each numerical range can be combined arbitrarily.
Furthermore, in the chemical heat storage material of the present disclosure, descriptions such as “magnesium oxide” and “inorganic salt” refer to anhydrides and hydrates having arbitrary hydration numbers unless otherwise specified.

FIG. 1 shows a schematic diagram showing the configuration of one embodiment of the heat storage structure. The heat storage structure is formed from a chemical heat storage material 1 and a sealed container 2 that seals the chemical heat storage material. The sealed container has a property of impermeable to liquid water but permeable to water vapor (such property is hereinafter referred to as "moisture permeability". The degree to which a substance having moisture permeability allows water vapor to pass is referred to as "moisture permeability". ) at least in part. The sealed container 2 may include at least a portion of the water vapor permeable member. The sealed container 2 may be entirely made of a water vapor permeable member. In the heat storage structure of FIG. 1, the sealed container 2 is made of a water vapor permeable member.

The chemical heat storage material 1 is a substance that generates heat by hydration reaction and/or stores heat by dehydration reaction, and is composed of magnesium oxide, magnesium hydroxide, alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, and copper. , at least one inorganic salt selected from the group consisting of zinc and lead, at least one selected from the group consisting of organic salts and halides. Among them, those having a dehydration reaction temperature of 200° C. or less are preferable. Since the temperature at which the dehydration reaction occurs is 200° C. or less, unused heat in the factory can be used as a heat source, leading to effective utilization of heat.
The chemical heat storage material particularly preferably contains at least one selected from the group consisting of magnesium oxide and magnesium sulfate from the viewpoint of having a large heat storage amount per mass.

At least one inorganic salt, organic salt and halide selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead that can be contained in the chemical heat storage material include hydrated It is not particularly limited as long as it generates heat by the reaction and/or accumulates heat by the dehydration reaction.
Here, alkali metals refer to lithium, sodium, potassium, rubidium, cesium and francium. Alkaline earth metals refer to beryllium, magnesium, calcium, strontium, barium and radium. Preferred alkali metals are lithium and sodium, and preferred alkaline earth metals are magnesium and calcium.

At least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead includes carbonates, phosphates, sulfates, nitrates, silicates It preferably contains at least one selected from the group consisting of salts. and the group consisting of Na ₂ CO _{3.xH 2} O (x=0-10), Na ₃ PO _{4.yH 2} O (y=0-12) and MgSO _{4.zH 2} O (z=0-7). It is more preferable to include at least one selected from

Examples of at least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead include carbonates such as calcium carbonate and barium carbonate; Phosphates include magnesium phosphate and sodium phosphate, sulfates include sodium sulfate and magnesium sulfate, nitrates include magnesium nitrate and aluminum nitrate, and silicates include magnesium silicate and calcium silicate. be done.
Examples of at least one organic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead include formates, acetates, octylates and the like. Examples include fatty acid salts, aromatic carboxylic acid salts such as phthalates and benzoates, and sulfonates such as p-toluenesulfonates and ethanesulfonates. Among them, acetate is preferred. Acetates include sodium acetate, calcium acetate, magnesium acetate, nickel acetate, copper acetate, zinc acetate, lead acetate and the like.
Examples of at least one halide selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead include fluorides such as magnesium fluoride and calcium fluoride , chlorides such as magnesium chloride and calcium chloride, bromides such as magnesium bromide and calcium bromide, and iodides such as magnesium iodide and calcium iodide. Among them, magnesium chloride or calcium chloride is preferred.

A chemical heat storage material that stores heat by a hydration reaction is classified into a chemical heat storage material that forms a hydroxide by a hydration reaction and a chemical heat storage material that forms a hydrate. A chemical heat storage material that forms a hydroxide, for example, generates heat by a hydration reaction as shown in formula (1) and stores heat by a dehydration reaction as shown in formula (2).
MgO+ _H2O →Mg(OH) ₂ (1)
Mg(OH) ₂ →MgO+ _H2O (2)

A chemical heat storage material that forms a hydrate, for example, generates heat by a hydration reaction as shown in formula (3) and stores heat by a dehydration reaction as shown in formula (4). However, it is not limited to reactions between specific hydration numbers. For example, heat may be generated by a reaction that increases the hydration number from 1 to 6, or heat may be accumulated by a reaction that reduces the hydration number from 4 to 2.
_MgSO4 + _7H2O → _MgSO4.7H2O (3 _)
MgSO4.7H2O → _MgSO4 + _{7H2O (} 4)

Some chemical heat storage materials have high solubility in water and dissolve during the process of hydration reaction or dehydration reaction. The dissolution during the hydration reaction is caused by the water added for the hydration reaction, and the dissolution during the dehydration reaction is caused by the moisture desorbed from the chemical heat storage material itself. Examples of such _substances include _MgSO4.7H2O , _potassium alum _KAl ( _SO4 ) _2.12H2O , sodium _{thiosulfate Na2S2O3.5H2O ,} sodium carbonate _{Na2CO3 . 10H2O} can be mentioned. When the chemical heat storage material dissolves into a chemical heat storage material aqueous solution, in the heat storage structure of the present disclosure, the chemical heat storage material is sealed in a sealed container, and the sealed container is permeable to water vapor having a predetermined moisture permeability. Since the member is included in at least a part thereof, the chemical heat storage medium aqueous solution does not flow out of the sealed container, so the present disclosure is particularly effective in such a case.

The form of the chemical heat storage material is not particularly limited as long as the chemical heat storage material can undergo a hydration reaction. Quality is more preferred.

Regarding the hydration reaction of the chemical heat storage material, the moisture applied for the hydration reaction may be liquid water or water vapor. However, when using water vapor, the sealed container has a water vapor permeable member at least in part, so the sealed container may have a structure that cannot be opened and closed. It is preferable to have a structure that can be opened and closed.
As an example of a method of using the heat storage structure of the present embodiment, a part of the sealed container is opened, liquid water is poured into the chemical heat storage material in the heat storage state sealed in the sealed container, and the sealed container is immediately sealed. Close the stop container. Heat generation due to hydration reaction begins when water is poured. In addition, since the chemical heat storage material does not flow out even after the reaction, it can be used repeatedly if the chemical heat storage material is dehydrated and returned to the heat storage state.
As an example of another usage method, when steam is used, steam is supplied from the outside of the sealed container to cause the chemical heat storage material to generate heat due to a hydration reaction. Since the chemical heat storage material does not flow out even after the reaction, it can be used repeatedly if it is dehydrated and returned to the heat storage state. Even when water vapor is used, a part of the sealed container may have a structure that can be opened and closed as long as it is sealed during hydration and dehydration.
Other methods of use include, for example, liquid water and water vapor.
Heat generation from the chemical heat storage material can be repeated regardless of the reaction medium, but it may be used only once.

The dehydration reaction of the chemical heat storage material is not particularly limited as long as it can apply heat to the chemical heat storage material, but the temperature of the dehydration reaction is preferably 200° C. or less. Since the temperature of the dehydration reaction is 200° C. or less, unused heat in the factory can be used as a heat source, which leads to effective utilization of heat.
The dehydration reaction may be performed with the chemical heat storage material sealed in a sealed container, or only the chemical heat storage material may be dehydrated and then sealed in the sealed container.

The sealed container 2 seals the chemical heat storage material. By sealing the chemical heat storage material in the sealed container, an effect is obtained that the chemical heat storage material does not flow out of the sealed container. Here, "sealing the chemical heat storage material in the sealed container" means that the chemical heat storage material is surrounded by the sealed container, the chemical heat storage material does not flow out of the sealed container, and water outside the sealed container It refers to making it impossible to enter the inside of the sealed container. Of course, this does not preclude providing the sealed container with a mechanism capable of releasing the seal.

The material of the sealed container is not particularly limited, but a material that can withstand the operating temperature is desirable. There are two types of working temperatures: the maximum temperature reached during hydration and the dehydration temperature of the chemical heat storage material. If the chemical heat storage material is used only once, it should be able to withstand only the maximum temperature reached during hydration if it is dehydrated before being sealed in the sealed container. When the sealed container is used repeatedly, the sealed container is required to have heat resistance corresponding to the dehydration temperature of the chemical heat storage material.

From this point of view, the heat resistance temperature of the sealed container is preferably 70° C. or higher, more preferably 100° C. or higher. Also, it is preferably 900° C. or lower, more preferably 700° C. or lower.
The heat resistant temperature of the sealed container refers to the melting point of the sealed container, and the melting point of the sealed container can be measured by a known method. For example, the melting point of the sealed container can be measured by subjecting a portion of the sealed container to thermal analysis such as differential scanning calorimetry (DSC) or differential thermal analysis (DTA). Moreover, the heat-resistant temperature of the sealed container can be adjusted by changing the material of the sealed container.

When the dehydration temperature of the chemical heat storage material is less than 400°C, the material of the sealed container is preferably resin, porous metal, or porous ceramic. A ceramic porous body is preferred.

The sealed container is preferably a film. Although the thickness of the film is not particularly limited, it is preferably 1 μm or more, more preferably 10 μm or more. Moreover, it is preferably 1 mm or less, and more preferably 250 μm or less.

The sealed container includes at least a portion of the water vapor permeable member. The entire sealed container may be a water vapor permeable member, and FIG. 1 is an example thereof, and the entire sealed container functions as a water vapor permeable member. The water vapor permeable member has moisture permeability.
The water vapor permeable member has moisture permeability in order to ^cause a hydration and/or dehydration reaction while retaining the chemical heat storage material. be.
When the moisture permeability of the water vapor permeable member is within the above range, the effect of the water vapor permeable member not permeating liquid water but permeating water vapor can be obtained. Therefore, even when water is used as the reaction medium, an effect is obtained that the chemical heat storage material does not flow out. Steam can also be used as the reaction medium. In addition, the chemical heat storage material is not blown off by water vapor. Furthermore, even if the chemical heat storage material, which is highly soluble in water, dissolves in the sealed container during the process of hydration reaction or dehydration reaction, it will not flow out of the sealed container. .
If the moisture permeability of the water vapor permeable member is less than 200 g/(m ² ·24 h), the water vapor generated from the heat storage material during dehydration cannot escape outside the sealed container, and the pressure inside the sealed container increases, resulting in sealing. The container seal is easily broken.
Further, if the water vapor permeability of the water vapor permeable member is higher than 10000 g/(m ² ·24 h), the water pressure resistance of the water vapor permeable member becomes low, and there is a risk that the liquefied heat storage material will seep out onto the surface of the water vapor permeable member.

The moisture permeability of the water vapor permeable member is preferably 2000 to 9800 g/(m ² ·24 h) so that water vapor generated during dehydration can be smoothly discharged to the outside of the sealed container. As a result, it is possible to obtain the effect of preventing the sealing of the sealed container from breaking due to an increase in the internal pressure of the sealed container. Furthermore, it is more preferably 5000 to 9600 g/(m ² ·24 h) so as to increase the intake of water vapor and promote the hydration reaction.
Although the method for adjusting the moisture permeability of the water vapor permeable member is not particularly limited, for example, the water vapor permeable member may have pores 3 .

The diameter of the pores 3 of the water vapor permeable member is not particularly limited as long as the water vapor permeability of the water vapor permeable member is within the above range. Since the size of gaseous water molecules is 0.38 nm and the size of liquid water particles is 100 μm to 3000 μm, from the viewpoint of permeation of gaseous water molecules and not permeation of liquid water molecules, It is preferably 0.38 nm or more, and preferably 100 μm or less. However, this is not the case because the appropriate pore size differs depending on the water repellency and water pressure resistance of the surface of the water vapor permeable member.

The material of the water vapor permeable member is not particularly limited as long as it satisfies the above moisture permeability, but it is preferable that the water vapor permeable member contains a resin so that the heat storage structure can be in a flexible state. The resin is preferably a polyolefin resin such as polyethylene (PE) or polypropylene (PP), or a flexible resin such as a urethane resin such as thermoplastic polyurethane (TPU), more preferably perfluoroalkoxy, which has a high heat resistance temperature. Fluorine resins such as alkane (PFA) resins and polytetrafluoroethylene (PTFE) resins, polyimides (PI) such as polyamideimide and polyetherimide, polydimethylsiloxane (PDMS), silicone resins such as silicone rubber, polyetheretherketone (PEEK) resin, polyphenylene sulfide (PPS) resin such as linear polyphenylene sulfide and crosslinked polyphenylene sulfide, polyester (PEs) resin, more preferably polytetrafluoroethylene having high chemical resistance and high corrosion resistance. (PTFE) resin. Also, the water vapor permeable member may be a combination of resin such as fluorine-coated glass cloth and other materials such as inorganic substances.

The “water vapor transmission rate” is the amount of water vapor that passes through a unit area of film-like material for a certain period of time, and is measured according to JIS Z 0208 in the present disclosure.
Specifically, 35 g to 40 g of anhydrous calcium chloride of JIS K 8123 (which passes through a standard sieve of 2380 μm but does not pass through a standard sieve of 590 μm) was placed flat in a JIS L 1099 moisture permeable cup of φ60 mm as a moisture absorbent. Thereafter, a thin piece cut out from the sealed container was attached to a moisture-permeable cup and sealed using an oil compound as a sealing wax to prepare a sample. Also, a blank cup was produced by carrying out the same operation without adding the moisture absorbent to the moisture permeable cup.
The sample and blank cup obtained above are placed in a constant temperature and humidity apparatus at a temperature of 40 ± 0.5 ° C., a relative humidity of 90 ± 2%, and a wind speed of 0.5 to 2.5 m / s for a certain period of time. It was removed at intervals and weighed to determine the weight gain. The weight increase of the sample is the sum of the weight increase of the moisture absorbent and the weight increase of the moisture permeable cup containing the flakes due to the absorption of water by the moisture absorbent, so it was corrected by the weight increase of the blank cup.
JIS Z 0208 states that "the measurement must be completed before the mass of the moisture absorbent increases by 10% or more." This is because if the mass increase of the moisture absorbent is 10% or more, the reactivity of the moisture absorbent decreases, and there is a possibility that accurate measurement cannot be performed.
Since the present disclosure includes a water vapor permeable member with high moisture vapor transmission rate, the weight gain over a short period of time was evaluated so that the weight gain of the absorbent material did not exceed 10%. In addition, in order to confirm that the mass increase is constant, the mass increase for 1 hour up to 1 hour after standing in the constant temperature and humidity device, and 1 hour from 1 hour to 2 hours after standing still. After confirming that the mass increase was within 5%, the moisture permeability was calculated by the following formula (6) based on the mass increase for 1 hour from 1 hour to 2 hours after standing.
Moisture permeability (g/( ^m2・24h))=240×m/(t・s) (6)
s: Moisture permeable area (cm ² )
t: sum of the time (h) of the last two weighing intervals in which the measurements were made. 1 hour for this disclosure.
m: sum of mass increments (mg) over the last two weighing intervals in which the measurement was made. Mass gained in 1 hour from 1 hour to 2 hours in the present disclosure.

Since the heat storage structure of the present disclosure can prevent the chemical heat storage material from flowing out of the sealed container during hydration and/or dehydration, it can theoretically be used repeatedly any number of times.
As for how to use the heat generated from the chemical heat storage material, the generated heat is transmitted to the sealed container and warms the sealed container. In addition to contact heating, there are other ways of warming. If the moisture added for the hydration reaction is liquid water, the hydration rate with the chemical heat storage material is faster than steam, and heat is generated rapidly. Steam can be used to heat objects. When the moisture added for the hydration reaction is water vapor, the water vapor is warmed by the reaction with the chemical heat storage material, and the water vapor functions as warm air. can be done.

FIG. 2 is a schematic diagram showing the configuration of another embodiment of the heat storage structure of the present disclosure. In this embodiment, the sealed container is composed of the chemical heat storage material 4 of the present disclosure, the sealed container main body 5 and the water vapor permeable member 6 described above. In this way, the sealed container can also be configured to partially include the water vapor permeable member. It can be used as a heat storage structure by allowing water vapor to flow in and out of the water vapor permeable member. In FIG. 2, the sealed container main body may be a member impermeable to water vapor, but may be a water vapor permeable member.

FIG. 3 is a schematic diagram showing the configuration of one embodiment of the heat storage system of the present disclosure. The present embodiment includes a heat storage device 13 having the heat storage structure of the present disclosure described above, a blower 7 and a water storage tank 8 as a water vapor supplier for performing a hydration reaction, water 9, and heat supply for performing a dehydration reaction. It is composed of a hot air generator 10 as a machine, a heating chamber 11 using heat generated from a heat accumulator, and a hot air outlet 12 .

The procedure for generating heat in FIG. 3 is, for example, as follows.
The heat accumulator 13 includes a heat storage structure having a chemical heat storage material in a heat storage state in a form capable of supplying steam sent from a steam supply device to the chemical heat storage material. At this time, the heat storage device 13 may be newly provided with a heat storage structure having a chemical heat storage material in a heat storage state, or a heat storage structure having a chemical heat storage material in a state in which heat has already been generated (hereinafter referred to as a non-heat storage state). may be brought into a heat storage state in a heat storage procedure described later.
After that, air is blown by the blower 7, and steam is sent from the water tank 8 in which the water 9 is stored to the heat accumulator 13. - 特許庁By sending water vapor to the heat accumulator 13, the chemical heat storage material in the heat storage structure of the heat accumulator 13 undergoes a hydration reaction. The heat generated by the hydration reaction warms the heat accumulator 13 and the heat generated by the hydration reaction is sent to the heating chamber 11 . As a result, heat becomes available in the heating chamber 11 . At this time, the object to be warmed may be placed in the heating chamber 11 or the object to be warmed may be placed in the heat accumulator 13 .

The procedure for heat storage in FIG. 3 is, for example, as follows.
The heat accumulator 13 is provided with a heat storage structure having a chemical heat storage material in an unstored state so that the heat sent from the heat supply device can be supplied to the chemical heat storage material. At this time, the heat accumulator 13 may be newly provided with a heat storage structure having a chemical heat storage material in a non-heat-storing state, or the heat storage structure having a chemical heat storage material in a heat-storing state may be subjected to the above-described heat generation procedure to obtain a chemical heat storage material. may be set to an unheated state.
After that, hot air is generated by the hot air generator 10 and sent to the heat accumulator 13 . By sending hot air to the heat accumulator 13, the chemical heat storage material in the heat storage structure of the heat accumulator 13 undergoes a dehydration reaction. The dehydration reaction brings the chemical heat storage material into a heat storage state.
Incidentally, the water vapor generated by the dehydration reaction may be condensed in a water tank and used for the hydration reaction. Using unused heat from the factory as the heat source for dehydration leads to effective utilization of heat.

EXAMPLES The present disclosure will be described more specifically below with reference to examples, but the present disclosure is not limited to the following examples.

[Example 1]
(Preparation of heat storage structure)
A heat storage structure was produced by putting 0.200 g of the chemical heat storage material MgSO ₄ .7H ₂ O into a PTFE three-sided bag of 23 mm × 23 mm × t 0.1 mm as a sealed container, and sealing the opening by welding a PFA film. .

(Dehydration of heat storage structure)
After weighing the produced heat storage structure, it was heated in an electric furnace and dehydrated until the mass did not decrease. The heating temperature was higher than the temperature at which water is desorbed from the chemical heat storage material and lower than the heat resistance temperature of the sealed container. To confirm dehydration, the chemical heat storage material was taken out from the heat storage structure and structural analysis was performed using an X-ray diffraction device SmartLab manufactured by Rigaku Co., Ltd. It was confirmed that the structure changed to a structure in which some or all of the water was removed. .

(Hydration of heat storage structure)
The dehydrated heat storage structure was placed in a constant temperature and humidity apparatus, weighed periodically, and hydrated until the mass stopped increasing. As confirmation of hydration, structural analysis was performed using an X-ray diffractometer SmartLab manufactured by Rigaku Corporation in the same manner as dehydration, and it was confirmed that the chemical heat storage material had returned to its original structure.

(Evaluation of outflow prevention)
The outflow prevention effect of the chemical heat storage material of the produced heat storage structure was evaluated by performing the above-described dehydration and hydration. As evaluation indexes, the sealing state of the sealed container and the seepage of water from the surface of the sealed container were used. Each evaluation criterion was defined as follows.
Confirmation of the sealed state of the sealed container was an evaluation of whether or not the water vapor generated from the chemical heat storage material during dehydration could be discharged out of the sealed container. The confirmation of the seepage of water was determined by the color of the cobalt chloride paper when the heat storage structure was taken out from the thermo-hygrostat and the cobalt chloride paper was brought into contact with the surface of the sealed container. When the cobalt chloride paper did not turn red, it was determined that water had not oozed out from the surface of the sealed container, and when it turned red, water had oozed out from the surface of the sealed container. Evaluation results are shown in Table 1-1.
[Sealed State of Sealed Container]
A: The sealing of the sealed container was not broken during dehydration.
B: Sealing of the sealed container was broken during dehydration.
[Water oozes out from the surface of the sealed container]
A: Water did not seep out from the surface of the sealed container during hydration.
B: Water seeped out from the surface of the sealed container during hydration.
[Outflow prevention effect]
When the sealed state of the sealed container, which is an evaluation index, and the seepage of water from the surface of the sealed container, which are evaluation indexes, were evaluated A, the chemical heat storage material did not flow out from the sealed container.
When either the sealed state of the sealed container or the seepage of water from the surface of the sealed container was evaluated as B, the chemical heat storage material flowed out of the sealed container.

[Examples 2 to 47]
0.200 g of the chemical heat storage material listed in Table 1-1 or Table 1-2 is placed in a three-sided bag of 23 mm × 23 mm (thickness varies depending on material and moisture permeability) as a sealed container, and the opening is thermocompression bonded. A heat storage structure was produced by sealing with a hot-melt agent or a heat-resistant adhesive tape (API-214A from Chuko Kasei Kogyo Co., Ltd.). For the three-sided bag, a commercially available product or a product processed with a moisture-permeable film made of the materials listed in Table 1-1 or Table 1-2 was used, and even if the material was the same, the moisture permeability was adjusted by adjusting the thickness and pore size. . When the material is crystalline resin, it is produced by the biaxial stretching method, and each raw material is made into a paste at a temperature above the glass transition point and below the melting point, and after extrusion molding, it is stretched perpendicular to the extrusion direction to create a water vapor permeable member. was made. The thickness and pore size were controlled by controlling the stretching temperature and stretching ratio. In addition, in the case of non-crystalline resin such as PI, it is produced by the phase separation method, and a paste that is a mixture of each raw material and fine particles such as silica is applied and molded into a film. A water vapor-permeable member was produced by removing the fine particles. The thickness of the water vapor permeable member was adjusted according to the thickness of the molded body, and the porosity was adjusted according to the size and addition rate of the fine particles to be removed. The fabricated heat storage structure is dehydrated in an electric furnace at a temperature higher than the dehydration temperature of water in the heat storage material and lower than the heat resistance temperature of the sealed container, and then a hydration reaction is performed under hydration conditions suitable for each chemical heat storage material. , evaluated the outflow prevention effect of the chemical heat storage material. The results are shown in Tables 1-1 and 1-2.

[Comparative Examples 1 and 2]
A heat storage structure was produced in the same manner as in the example, and the outflow prevention effect was evaluated in the same manner as in the example.

　表１－１及び表１－２中のＰＴＦＥはポリテトラフルオロエチレン樹脂を、ＰＩはポリイミド樹脂を、ＰＰはポリプロピレン樹脂を、ＰＥはポリエチレン樹脂を、ＴＰＵは熱可塑性ポリウレタン樹脂を、ＰＥＥＫはポリエーテルエーテルケトン樹脂を、ＰＰＳはポリフェニレンスルフィド樹脂を、ＰＥｓはポリエステル樹脂を、それぞれ示す。

In Tables 1-1 and 1-2, PTFE is polytetrafluoroethylene resin, PI is polyimide resin, PP is polypropylene resin, PE is polyethylene resin, TPU is thermoplastic polyurethane resin, and PEEK is polyether. An ether ketone resin, PPS, a polyphenylene sulfide resin, and PEs, a polyester resin, respectively.

The present disclosure relates to the following configurations.
(Configuration 1)
A heat storage structure having a sealed container and a chemical heat storage material sealed in the sealed container,
The sealed container includes at least a portion of a water vapor permeable member,
The chemical heat storage material is
A group consisting of magnesium oxide, magnesium hydroxide, and at least one inorganic salt, organic salt and halide selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead. including at least one selected from
The chemical heat storage material is a substance that generates heat by a hydration reaction and/or stores heat by a dehydration reaction,
A heat storage structure, wherein the moisture permeability of the water vapor permeable member is 200 to 10000 g/(m ² ·24 h).
(Configuration 2)
The heat storage structure according to configuration 1, wherein the heat resistant temperature of the sealed container is 70°C or higher and 700°C or lower.
(Composition 3)
The heat storage structure according to configuration 1 or 2, wherein the water vapor permeable member comprises a resin.
(Composition 4)
The heat storage structure according to configuration 3, wherein the resin includes at least one selected from the group consisting of fluororesin, polyimide resin, silicone resin, polyetheretherketone resin, polyphenylene sulfide resin and polyester resin.
(Composition 5)
A heat storage structure according to configuration 3 or 4, wherein the resin comprises polytetrafluoroethylene resin.
(Composition 6)
The heat storage structure according to any one of configurations 1 to 5, wherein the sealed container is a film.
(Composition 7)
At least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead is carbonate, phosphate, sulfate, nitrate and silicate The heat storage structure according to any one of configurations 1 to 6, comprising at least one selected from the group consisting of salts.
(Composition 8)
At least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead is Na ₂ CO _{3.xH 2} O (x=0 to 10 ), Na ₃ PO _{4.yH 2} O (y=0 to 12), and MgSO _{4.zH 2} O (z=0 to 7). A heat storage structure according to claim 1.
(Composition 9)
A heat storage system comprising a steam supplier for performing a hydration reaction, a heat supplier for performing a dehydration reaction, and a heat accumulator,
The heat storage device has a heat storage structure according to any one of configurations 1 to 8,
heat is sent to the heat accumulator by the heat supplier;
The chemical heat storage material contained in the heat storage structure undergoes a dehydration reaction with the heat sent to the heat accumulator, whereby heat is stored in the chemical heat storage material,
Further, steam is sent to the heat accumulator by the steam supplier,
The heat stored in the chemical heat storage material is extracted by a hydration reaction of the chemical heat storage material contained in the heat storage structure.
heat storage system.

1 Chemical heat storage material, 2 Sealed container, 3 Pores, 4 Chemical heat storage material, 5 Sealed container body, 6 Water vapor transmission member, 7 Blower, 8 Water tank, 9 Water, 10 Hot air generator, 11 Heating chamber, 12 Hot air outlet, 13 heat accumulator

Claims (9)

A heat storage structure having a sealed container and a chemical heat storage material sealed in the sealed container,
The sealed container includes at least a portion of a water vapor permeable member,
The chemical heat storage material is
A group consisting of magnesium oxide, magnesium hydroxide, and at least one inorganic salt, organic salt and halide selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead. including at least one selected from
The chemical heat storage material is a substance that generates heat by a hydration reaction and/or stores heat by a dehydration reaction,
A heat storage structure, wherein the moisture permeability of the water vapor permeable member is 200 to 10000 g/(m ² ·24 h). The heat storage structure according to claim 1, wherein the heat resistant temperature of the sealed container is 70°C or higher and 700°C or lower. The heat storage structure according to claim 1 or 2, wherein the water vapor permeable member contains resin. The heat storage structure according to claim 3, wherein the resin contains at least one selected from the group consisting of fluororesin, polyimide resin, silicone resin, polyetheretherketone resin, polyphenylene sulfide resin and polyester resin. The heat storage structure according to claim 3 or 4, wherein the resin contains polytetrafluoroethylene resin. The heat storage structure according to any one of claims 1 to 5, wherein the sealed container is a film. At least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead is carbonate, phosphate, sulfate, nitrate and silicate The heat storage structure according to any one of claims 1 to 6, comprising at least one selected from the group consisting of salts. At least one inorganic salt selected from the group consisting of alkali metals, alkaline earth metals, aluminum, manganese, iron, nickel, copper, zinc and lead is Na ₂ CO _{3.xH 2} O (x=0 to 10 ), Na ₃ PO _{4.yH 2} O (y=0 to 12) and MgSO _{4.zH 2} O (z=0 to 7). or the heat storage structure according to claim 1. A heat storage system comprising a steam supplier for performing a hydration reaction, a heat supplier for performing a dehydration reaction, and a heat accumulator,
The heat storage device has the heat storage structure according to any one of claims 1 to 8,
heat is sent to the heat accumulator by the heat supplier;
The chemical heat storage material contained in the heat storage structure undergoes a dehydration reaction with the heat sent to the heat accumulator, whereby heat is stored in the chemical heat storage material,
Further, steam is sent to the heat accumulator by the steam supplier,
The heat stored in the chemical heat storage material is extracted by a hydration reaction of the chemical heat storage material contained in the heat storage structure.
heat storage system.

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