JP2017003182A - Heat storage device and heat storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat storage device capable of releasing overcooling of a heat storage material forming a clathrate hydrate by cooling, with a smaller amount of energy.SOLUTION: A heat storage device 100 includes a heat storage material 10 forming clathrate hydrate by cooling, and a pair of electrodes 22 contacting with the heat storage material 10. At least one of the pair of electrodes 22 contains copper or silver, or the heat storage material 10 contains silver ions when the heat storage material 10 is in a liquid state. When the heat storage material 10 is cooled in the liquid state and then in an overcooled state, voltage is applied between the pair of electrodes 22, to release the overcooled state of the heat storage material 10 and generate clathrate hydrate.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a heat storage device and a heat storage method.

  Conventionally, a heat storage device using a heat storage material forming clathrate hydrate (clathrate hydrate) has been proposed.

  For example, Patent Document 1 describes a hydrate generating apparatus 300 including a heat storage tank 310, a main refrigerator 313, and a sub refrigerator 320 as shown in FIG. Inside the heat storage tank 310, a heat storage body 311 is provided. The heat storage body 311 includes a multi-tube collecting pipe in which a heat transfer pipe 317 is connected between an upper header pipe 315 and a lower header pipe 316. The heat storage body 311 accommodates a guest material that is a hydrocarbon such as cyclopentane or pentane and water that is a host material. The heat storage tank 310 is filled with a refrigerant 312 for cooling the heat storage body 311 or recovering cold heat. This refrigerant is cooled by the main refrigerator 313. A supercooling section 318 is provided in the upper header pipe 315. The supercooling unit 318 is controlled by the sub refrigerator 320.

  When the clathrate hydrate is produced using cyclopentane as the guest material in the hydrate production apparatus 300, the production temperature of the hydrate is about 7 ° C. The heat storage body 311 is cooled to a temperature of 5 to 3 ° C., which is slightly lower than 7 ° C. In this state, cyclopentane and water are kept in a supercooled liquid state with respect to the production temperature (about 7 ° C.). In this state, the sub refrigerator 320 is operated, and the supercooling unit 318 cools the surrounding supercooled liquid to near −6 ° C., so that the supercooled water becomes ice, and this ice is seeded. As a result, a clathrate hydrate seed is formed, and hydrate formation is propagated based on the seed to form a clathrate hydrate between the guest material in the heat storage body 311 and water as the host material. In this way, the supercooling is released.

JP 2010-121800 A

  The hydrate production | generation apparatus 300 of patent document 1 has room to reduce energy required in order to cancel | release the supercooling of the thermal storage material which forms a clathrate hydrate by cooling. Therefore, the present disclosure provides a heat storage device that can release supercooling of a heat storage material that forms a clathrate hydrate by cooling with less energy.

This disclosure
A heat storage material that forms a clathrate hydrate by cooling;
A pair of electrodes in contact with the heat storage material,
At least one of the pair of electrodes contains copper or silver, or when the heat storage material is in a liquid state, the heat storage material contains silver ions,
When the heat storage material is cooled in a liquid state and is in a supercooled state, a voltage is applied between the pair of electrodes so as to release the supercooled state of the heat storage material and generate the clathrate hydrate. The
A heat storage device is provided.

  Said heat storage apparatus can cancel | release the supercooling of the thermal storage material which forms a clathrate hydrate by cooling with less energy.

Sectional drawing which shows the thermal storage apparatus which concerns on embodiment of this indication Sectional drawing which shows the thermal storage apparatus which concerns on the modification of this indication Flow chart showing the heat storage method of the present disclosure Sectional drawing which shows the thermal storage apparatus which concerns on another modification of this indication. Sectional drawing which shows the thermal storage apparatus which concerns on another modification of this indication. Diagram showing a conventional hydrate generator

  A heat storage device using ice as a heat storage material is known. For example, a technique is known in which ice is produced using low-cost nighttime electricity and cold energy stored in the ice is used for daytime cooling. Ice has a large heat of fusion (about 334 J / g) and is an excellent heat storage material. Since the melting point of ice is 0 ° C., it is necessary to cool to −5 ° C. in order to produce ice. For this reason, when producing ice using a refrigerator, it is difficult to increase the coefficient of performance (COP) of the refrigerator. In this case, for example, the COP is reduced by about 20% compared to the case where the refrigerator is operated at 0 ° C. For this reason, this technology has room for improvement from the viewpoint of reducing energy consumption.

  It is desirable to use a substance having a melting point of 5 ° C. to 30 ° C. as a heat storage material for cooling from the viewpoint of reducing energy consumption. However, a single compound having a melting point in that temperature range is, for example, paraffin such as tetradecane (melting point: 5 ° C., heat of fusion 210 J / g) or pentadecane (melting point: 9.9 ° C., heat of fusion: 158 J / g). Limited to specific compounds such as series compounds. It is difficult to produce high-purity tetradecane or pentadecane industrially at low cost. Paraffinic compounds are difficult to use in large quantities because they have low thermal conductivity or low density when in liquid form. For this reason, it is difficult to use a paraffinic compound such as tetradecane or pentadecane as a heat storage material for cooling.

  On the other hand, among materials that form clathrate hydrates by cooling, such as clathrate hydrates of quaternary ammonium salts, there are materials having a melting point higher than 0 ° C. (temperature at which clathrate hydrate starts to decompose). is there. For example, tetrabutylammonium bromide (TBAB) clathrate hydrate has a melting point of about 5-12 ° C. The clathrate hydrate of tetrabutylammonium chloride (TBAC) has a melting point of about 15 ° C. The clathrate hydrates of tetrabutylammonium fluoride (TBAF) and tetrabutylammonium hydroxide (TBAOH) have a melting point of about 27 ° C. For this reason, it is anticipated that energy consumption will be reduced by using the material which forms a clathrate hydrate by cooling instead of ice as a heat storage material for cooling. However, the material that forms clathrate hydrate by cooling exhibits large supercooling, and in some cases, it is necessary to cool to −6 ° C. or lower in order to release the supercooling, that is, to produce clathrate hydrate. .

  For example, in the hydrate production | generation apparatus 300 of patent document 1, the supercooling part 318 is cooling the surrounding supercooled liquid to -6 degreeC vicinity. For this reason, in the hydrate production | generation apparatus 300 of patent document 1, much energy is needed for cancellation | release of supercooling.

The first aspect of the present disclosure is:
A heat storage material that forms a clathrate hydrate by cooling;
A pair of electrodes in contact with the heat storage material,
At least one of the pair of electrodes contains copper or silver, or when the heat storage material is in a liquid state, the heat storage material contains silver ions,
When the heat storage material is cooled in a liquid state and is in a supercooled state, a voltage is applied between the pair of electrodes so as to release the supercooled state of the heat storage material and generate the clathrate hydrate. The
A heat storage device is provided.

  According to the first aspect, the clathrate hydrate seed is formed by applying a voltage to the pair of electrodes and applying electrical stimulation to a part of the supercooled heat storage material. The generation of clathrate hydrate propagates to the entire heat storage material starting from the seed of the clathrate hydrate, and the clathrate hydrate is quickly generated in the entire heat storage material, and the supercooling is released. Since the heat storage device according to the first aspect can release supercooling by applying a voltage to the pair of electrodes, it can release the supercooling of the heat storage material forming the clathrate hydrate by cooling with less energy.

  According to a second aspect of the present disclosure, in addition to the first aspect, the heat storage material includes tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, and tetrabutylammonium as a guest material of the clathrate hydrate. A heat storage device is provided that includes one or more quaternary ammonium salts selected from the group consisting of hydroxides. According to the second aspect, since the heat storage material has a relatively high melting point, the energy consumption of the heat storage device can be advantageously reduced.

  According to a third aspect of the present disclosure, in addition to the first aspect or the second aspect, at least one of the pair of electrodes includes a heat storage device including copper or silver. According to the 3rd aspect, even if silver ion is not contained in the heat storage material of a liquid state, the supercooled state of a heat storage material can be cancelled | released by the application of the voltage to a pair of electrode.

  According to a fourth aspect of the present disclosure, in addition to any one of the first to third aspects, the heat storage material provides a heat storage device including silver ions when the heat storage material is in a liquid state. . According to the fourth aspect, regardless of whether or not at least one of the pair of electrodes contains copper or silver, the supercooled state of the heat storage material can be canceled by applying a voltage to the pair of electrodes.

In addition to any one of the first to fourth aspects, the fifth aspect of the present disclosure includes:
A housing,
A heat storage material container containing the heat storage material, wherein a flow path of a heat medium for applying heat to the heat storage material or recovering heat from the heat storage material includes an inner peripheral surface of the housing and the heat storage material. A heat storage material container disposed in the internal space of the housing, so as to be formed between the outer peripheral surface of the material container,
A pair of funnel-shaped end members disposed at both ends of the casing in the direction in which the heat medium flows and having an inner diameter that expands toward the casing;
A pair of rectifying members that are in contact with each of the both ends of the casing and are fixed to the inside of each of the end members, and regulate the flow of the heat medium having a plurality of through holes,
A heat storage device is provided.

  According to the fifth aspect, the pair of end members and the pair of rectifying members efficiently transfer the heat medium to the heat medium flow path formed between the inner peripheral surface of the housing and the outer peripheral surface of the heat storage material container. It can flow. Thereby, the provision of heat to the heat storage material and the recovery of heat from the heat storage material can be efficiently performed.

The sixth aspect of the present disclosure is:
A step of preparing the heat storage device according to any one of the first to fifth aspects in a state where the heat storage material forms the clathrate hydrate;
Increasing the temperature of the heat storage material to decompose the clathrate hydrate;
Cooling the heat storage material to form the clathrate hydrate from the heat storage material in a liquid state, and
In the cooling step, when the heat storage material is in a liquid state and a supercooling state, a voltage is applied to the pair of electrodes to release the supercooling state of the heat storage material and generate the clathrate hydrate. A cooling release step, and a heat recovery step of recovering heat released from the heat storage material in association with release of the supercooled state of the heat storage material.
Provide a heat storage method.

  According to the sixth aspect, since the supercooling can be canceled by applying a voltage to the pair of electrodes, the supercooling of the heat storage material forming the clathrate hydrate by cooling can be canceled with less energy.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

  As shown in FIG. 1, the heat storage device 100 of the present disclosure includes a heat storage material 10 and a pair of electrodes 22. The heat storage material 10 forms a clathrate hydrate by cooling. That is, the heat storage material 10 includes a guest substance and water that is a host substance. The pair of electrodes 22 are in contact with the heat storage material 10. At least one of the pair of electrodes 22 contains copper or silver, or when the heat storage material 10 is in a liquid state, the heat storage material 10 contains silver ions. In the heat storage device 100, when the heat storage material 10 is cooled in a liquid state and is in a supercooled state, the supercooled state of the heat storage material 10 is released to generate a clathrate hydrate. A voltage is applied. Thereby, the heat storage device 100 can release the supercooling of the heat storage material 10 with less energy by applying a voltage to the pair of electrodes 22.

  For example, the heat storage device 100 includes a voltage application circuit 2 as shown in FIG. The voltage application circuit 2 includes a DC power supply 21 a and a switch 23. Each of the pair of electrodes 22 is electrically connected to the DC power supply 21a by wiring, and a switch 23 is disposed between one of the pair of electrodes 22 and the DC power supply 21a. A voltage is applied between the pair of electrodes 22 by closing the switch 23. In addition, as shown in FIG. 2, each of a pair of electrode 22 may be electrically connected to AC power supply 21b by wiring.

  The guest substance contained in the heat storage material 10 is not particularly limited as long as a clathrate hydrate is formed by cooling. The heat storage material 10 is, for example, one or more first members selected from the group consisting of tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, and tetrabutylammonium hydroxide as a clathrate hydrate guest substance. Contains quaternary ammonium salts. Thereby, since the thermal storage material 10 has a comparatively high melting | fusing point (for example, 5 to 30 degreeC), the energy consumption of the thermal storage apparatus 100 can be reduced advantageously. The melting point is the melting (clathrate hide) of the heat storage material 10 in the DSC curve obtained when the temperature of the heat storage material 10 is raised at a rate of 1 ° C./min using a differential scanning calorimeter (DSC). It means the temperature corresponding to the intersection of the tangent and the baseline at the inflection point of the melting peak that appears when the rate decomposition) begins. Supercooling means that the heat storage material is in a liquid state at a temperature below the melting point. The heat storage material 10 may contain any one of the above-described quaternary ammonium salts, or may contain a combination of two or more of the above-described quaternary ammonium salts.

  When at least one of the pair of electrodes 22 contains copper or silver, even if the heat storage material 10 in the liquid state does not contain silver ions, the supercooled state of the heat storage material 10 is changed by applying a voltage to the pair of electrodes 22. Can be canceled.

  When the heat storage material 10 contains silver ions when the heat storage material 10 is in a liquid state, voltage is applied to the pair of electrodes 22 regardless of whether or not at least one of the pair of electrodes 22 contains copper or silver. Thus, the supercooled state of the heat storage material 10 can be released.

  As shown in FIG. 1 or FIG. 2, for example, the heat storage device 100 may include a housing 30, a heat storage material container 12, a pair of end members 31, and a pair of rectifying members 40. The housing 30 has, for example, a cylindrical shape with openings formed at both ends. Moreover, the housing | casing 30 is made from the material which has heat insulation. The heat storage material container 12 accommodates the heat storage material 10 and is made of a material having heat conductivity. In the heat storage material container 12, the flow path 15 of the heat medium for applying heat to the heat storage material 10 or recovering heat from the heat storage material 10 is between the inner peripheral surface of the housing 30 and the outer peripheral surface of the heat storage material container 12. It is arrange | positioned in the interior space of the housing | casing 30 so that it may be formed. The pair of end members 31 are disposed at both ends of the housing 30 in the direction in which the heat medium flows. The pair of end members 31 are funnel-shaped members having an inner diameter that expands toward the housing 30. Each of the pair of end members 31 is fixed to either end of the housing 30. The pair of end members 31 form a heat medium inlet and a heat medium outlet of the heat storage device 100. The pair of rectifying members 40 are fixed to the inner sides of the end members 31 in contact with both ends of the housing 30 in the direction in which the heat medium flows. The pair of rectifying members 40 has a plurality of through holes and functions to regulate the flow of the heat medium.

  For example, when the heat medium passes through the left end member 31 in FIG. 1 or 2 and flows into the heat storage device 100, the flow rate of the heat medium decreases in the internal space of the end member 31. Thereafter, the heat medium passes through the plurality of through holes of the rectifying member 40 and is guided to the flow path 15 of the heat medium formed inside the housing 30. For this reason, the spatial dispersion | variation in the flow velocity of the heat medium which flows through the flow path 15 of a heat medium is suppressed. As a result, the heat medium can efficiently flow through the flow path 15 of the heat medium. As a result, in the heat storage device 100, heat is applied to the heat storage material 10 and heat is recovered from the heat storage material 10 efficiently.

  The pair of electrodes 22 has an outer portion exposed to the outside of the housing 30 and an inner portion extending through the heat storage material container 12 in the inner space of the housing 30. The number of heat storage material containers 12 arranged in the internal space of the housing 30 is not particularly limited, but when a plurality of heat storage material containers 12 are arranged in the internal space of the housing 30, the inner portions of the pair of electrodes 22 Extends through all of the plurality of heat storage material containers 12. Instead, the heat storage device 100 includes a plurality of pairs of electrodes 22, and the heat storage material 10 accommodated in all the heat storage material containers 12 is in contact with any one of the pairs of electrodes 22. Good. In this case, the plurality of pairs of electrodes 22 are electrically connected in parallel to the DC power supply 21a or the AC power supply 21b. The distance between the portions of the pair of electrodes 22 that are in contact with the heat storage material 10 is not particularly limited, and is, for example, 1 mm to 15 mm. In addition, the shape of the pair of electrodes 22 is not particularly limited, and is, for example, a plate shape or a wire shape. Either of the pair of electrodes 22 may contain copper or silver. Moreover, when the heat storage material 10 contains a silver ion when the heat storage material 10 is in a liquid state, at least one of the pair of electrodes 22 or both of the pair of electrodes 22 is, for example, a metal or carbon other than copper or silver. It may be made of (graphite).

  The arrangement of the inner portions of the pair of electrodes 22 in the flow direction of the heat medium is not particularly limited. For example, the inner portions of the pair of electrodes 22 are disposed at a position closer to the heat medium inlet than the heat medium outlet in the flow direction of the heat medium. When the heat storage material 10 is cooled by the heat medium, the temperature of the heat storage material 10 that exists near the inlet of the heat medium tends to be lower than the temperature of the heat storage material 10 that exists near the outlet of the heat medium. By disposing the inner portions of the pair of electrodes 22 at such positions, the supercooling of the heat storage material 10 can be advantageously canceled.

  Next, an example of a heat storage method using the heat storage device 100 will be described. As illustrated in FIG. 3, the heat storage method of the present disclosure includes a process S1, a process S2, and a process S3. Step S3 includes step S31, step S32, and step S33.

  Step S1 is a step of preparing the heat storage device 100 in a state where the heat storage material 10 forms a clathrate hydrate.

  Step S2 is a step of increasing the temperature of the heat storage material 10 to decompose the clathrate hydrate. In step S2, for example, a heat medium having a temperature higher than the melting point of the clathrate hydrate formed by the heat storage material 10 passes through the flow path 15 of the heat medium from one end member 31 toward the other end member 31. As described above, this is performed by supplying a heat medium into the heat storage device 100.

  Step S3 is a cooling step for cooling the heat storage material 10 so that clathrate hydrate is formed from the heat storage material 10 in a liquid state. In step S3, for example, the heat storage device 100 is configured such that a heat medium having a temperature lower than the temperature of the heat storage material 10 passes through the flow path 15 of the heat medium from one end member 31 toward the other end member 31. This is done by supplying a heat medium inside.

  Step S31 is a part of step S3 and is a step of cooling the heat storage material 10 so that the heat storage material 10 is in a liquid state and a supercooled state.

  In step S32, when the heat storage material 10 is in a liquid state and in a supercooled state, a voltage is applied to the pair of electrodes 22 to release the supercooled state of the heat storage material 10 to generate a clathrate hydrate. It is a process. Step S32 is a step performed during the period of step S3, and is performed subsequent to step S31. For example, in step S32, the switch 23 is closed, and a DC voltage is applied to the pair of electrodes 22 by the DC power source 21a, or an AC voltage is applied to the pair of electrodes 22 by the AC power source 21b. Thereby, electrical stimulation is applied to the heat storage material 10 in the supercooled state, the metastable supercooled state is released, and a phase change to an energetically more stable crystalline state (solid state) is started. That is, a clathrate hydrate is generated. Thereby, the heat of solidification is released from the heat storage material 10. Step S32 is desirably executed in a range where the degree of supercooling obtained by subtracting the temperature of the heat storage material 10 from the melting point of the clathrate hydrate formed by the heat storage material 10 is in the range of 2 ° C to 10 ° C.

  In step S32, the magnitude of the voltage applied to the pair of electrodes 22 is not particularly limited, and is, for example, 1V to 5V. In addition, since the heat storage material 10 contains water as a host material, it is desirable that the electrolysis of water does not occur by applying a voltage to the pair of electrodes 22. From this point of view, the magnitude of the voltage applied to the pair of electrodes 22 is desirably 1.23 V or less. Moreover, when applying an alternating voltage to a pair of electrode 22, both amplitudes of an alternating voltage are 1Vpp-10Vpp, for example. The frequency of the AC voltage is not particularly limited, but is preferably 10 Hz or less in consideration of the moving speed of ions.

  Step S33 is a heat recovery step of recovering the heat released from the heat storage material 10 as the heat storage material 10 is released from the supercooled state. Step S33 is a part of step S3 and is performed subsequent to step S32. Specifically, the heat released from the heat storage material 10 is transferred to the heat medium flowing through the heat storage device 100 and collected.

(Modification)
The heat storage device 100 can be changed from various viewpoints. For example, the heat storage device 100 may include a temperature sensor 50 a and a controller 60 as shown in FIGS. 4 and 5. For example, as shown in FIG. 4, the temperature sensor 50 a is disposed inside an end member 31 that forms a heat medium outlet. Thereby, the temperature of the heat medium flowing out from the heat storage device 100 can be detected using the temperature sensor 50a. Moreover, the temperature sensor 50a may be arrange | positioned inside the thermal storage material container 12, as shown in FIG. Thereby, the temperature of the heat storage material 10 can be detected using the temperature sensor 50a. The controller 60 is a controller for controlling opening and closing of the switch 23. The controller 60 is connected to the temperature sensor 50a so as to receive a signal indicating the detection result of the temperature sensor 50a. The controller 60 is connected to the switch 23 so that a control signal for controlling opening and closing of the switch 23 can be transmitted to the switch 23. The controller 60 includes, for example, a calculation device such as a CPU, a main storage device such as a RAM that can temporarily store a calculation result by the calculation device, and an auxiliary storage device such as a ROM or EEPROM that stores a predetermined program. .

  For example, in step S3, the controller 60 calculates the degree of supercooling of the heat storage material 10 based on the detection result of the temperature sensor 50a. The controller 60 transmits a control signal for closing the switch 23 to the switch 23 when the calculated degree of supercooling of the heat storage material 10 is within a predetermined range (for example, 2 ° C. to 10 ° C.). As a result, the switch 23 is closed and a voltage is applied to the pair of electrodes 22.

  Further, when clathrate hydrate is formed in step S32, the temperature of the heat storage material 10 rises to near the melting point. Therefore, in step S32, the controller 60 determines whether or not a clathrate hydrate has been generated based on the detection result of the temperature sensor 50a. The controller 60 transmits a control signal for opening the switch 23 to the switch 23 when it is determined that the clathrate hydrate has been generated based on the detection result of the temperature sensor 50a. As a result, the switch 23 is opened and the application of voltage to the pair of electrodes 22 is stopped.

  The heat storage device and the heat storage method of the present disclosure will be described in more detail by way of examples. However, the present invention is not limited to the following examples.

<Example 1>
A 9 cc glass sample bottle is filled with 5 g of a mixture of 40 wt% TBAB and 60 wt% water, and a pair of wire-like silver electrodes (wire diameter: 1.5 mm) are placed in the mixture. It was immersed for about 10 mm. At this time, the distance between the pair of silver electrodes was about 3 to 5 mm. Thus, the heat storage device according to Example 1 was produced. In a differential scanning calorimeter (DSC), the tangent and base at the inflection point of the melting peak of the DSC curve obtained when the mixture of 40% by weight TBAB and 60% by weight water is heated at 1 ° C./min. The melting point of the mixture determined from the intersection with the line was 11.5 ° C. Next, the mixture in the sample bottle was completely melted in an atmosphere at 25 ° C. to obtain a TBAB aqueous solution having a concentration of 40% by weight. Next, the temperature in the sample bottle was lowered to 2 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of silver electrodes was connected to a DC power source and a voltage of 3 V was applied. About 10 minutes after the start of voltage application to the pair of silver electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle.

<Example 2>
A 9 cc glass sample bottle is filled with 5 g of a mixture of 34% by weight TBAOH and 66% by weight water, and a pair of wire-like silver electrodes (wire diameter: 1.5 mm) are added to the mixture. It was immersed for 10 mm. At this time, the distance between the pair of silver electrodes was about 3 to 5 mm. In this way, a heat storage device according to Example 2 was produced. In a differential scanning calorimeter (DSC), the tangent and base at the inflection point of the melting peak of the DSC curve obtained when the mixture of 34 wt% TBAOH and 66 wt% water is heated at 1 ° C./min. The melting point of the mixture determined from the intersection with the line was 27.2 ° C. Next, the mixture in the sample bottle was completely melted in an atmosphere of 35 ° C. to obtain a TBAOH aqueous solution having a concentration of 34% by weight. Next, the temperature in the sample bottle was lowered to 17 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of silver electrodes was connected to a DC power source and a voltage of 2 V was applied. About 10 years after the start of voltage application to the pair of silver electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle. Thereafter, the application of voltage to the pair of silver electrodes was stopped, and the mixture in the sample bottle was completely melted in an atmosphere at 35 ° C. to obtain a TBAOH aqueous solution. Next, the temperature in the sample bottle was lowered to 22 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of silver electrodes was connected to a DC power source and a voltage of 2 V was applied. About 9 minutes after the start of voltage application to the pair of silver electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle.

<Example 3>
A 9 cc glass sample bottle is filled with 5 g of a mixture of 34% by weight TBAOH and 66% by weight water, and a pair of wire-like copper electrodes (wire diameter: 1.5 mm) is added to the mixture by about 10 mm. Soaked. At this time, the distance between the pair of copper electrodes was about 3 to 5 mm. In this way, a heat storage device according to Example 3 was produced. Next, the mixture in the sample bottle was completely melted in an atmosphere of 35 ° C. to obtain a TBAOH aqueous solution having a concentration of 34% by weight. Next, the temperature in the sample bottle was lowered to 17 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of copper electrodes was connected to a DC power source, and a voltage of 3 V was applied. About 35 minutes after the start of voltage application to the pair of copper electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle.

<Example 4>
Using the heat storage device of Example 2, the mixture of 34 wt% TBAOH and 66 wt% water in the sample bottle was completely melted in an atmosphere of 35 ° C. to obtain a 34 wt% TBAOH aqueous solution. . Next, the temperature in the sample bottle was lowered to 17 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of silver electrodes were connected to a DC power source and a voltage of 1.0 V was applied. About 105 minutes after the start of voltage application to the pair of silver electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle.

<Example 5>
A 9 cc glass sample bottle was filled with 5 g of a mixture of 34 wt% TBAOH and 66 wt% water, and 0.05 g of silver (I) oxide (Ag ₂ O) was added. Further, a pair of wire-like carbon electrodes (wire diameter: 3.0 mm) were immersed in a TBAOH aqueous solution by about 10 mm. At this time, the distance between the pair of carbon electrodes was about 2 to 3 mm. In this way, a heat storage device according to Example 5 was produced. Next, in a 35 ° C. atmosphere, the mixture of TBAOH and water in the sample bottle was completely melted to obtain an aqueous TBAOH solution containing silver ions. Next, the temperature in the sample bottle was lowered to 17 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of carbon electrodes was connected to a DC power source, and a voltage of 3.0 V was applied. About 10 minutes after the start of voltage application to the pair of carbon electrodes, the formation of crystal nuclei was visually confirmed in the sample bottle.

<Comparative Example 1>
A 9 cc glass sample bottle was filled with 5 g of a mixture of 34% by weight TBAOH and 66% by weight water, and a pair of wire-like platinum electrodes (wire diameter: 1.0 mm) was added to the mixture. It was immersed for 10 mm. At this time, the distance between the pair of platinum electrodes was about 3 to 5 mm. In this manner, a heat storage device according to Comparative Example 1 was produced. Next, in a 35 ° C. atmosphere, the mixture of TBAOH and water in the sample bottle was completely melted to obtain a TBAOH aqueous solution having a concentration of 34% by weight. Next, the temperature in the sample bottle was lowered to 17 ° C. At this time, the mixture in the sample bottle maintained a liquid state and was in a supercooled state. Next, a pair of platinum electrodes were connected to a DC power source and a voltage of 3 V was applied. Even when the voltage application to the pair of platinum electrodes was continued for about 150 minutes, formation of crystal nuclei was not confirmed in the sample bottle.

  The heat storage device of the present disclosure can be used for applications that temporarily store cold energy in air conditioning or refrigeration.

DESCRIPTION OF SYMBOLS 10 Thermal storage material 12 Thermal storage material container 15 Heat medium flow path 22 A pair of electrodes 30 A housing | casing 31 A pair of end member 40 A pair of rectification members 100 A thermal storage apparatus

Claims (6)

A heat storage material that forms a clathrate hydrate by cooling;
A pair of electrodes in contact with the heat storage material,
At least one of the pair of electrodes contains copper or silver, or when the heat storage material is in a liquid state, the heat storage material contains silver ions,
When the heat storage material is cooled in a liquid state and is in a supercooled state, a voltage is applied between the pair of electrodes so as to release the supercooled state of the heat storage material and generate the clathrate hydrate. The
Thermal storage device.   The heat storage material is at least one fourth selected from the group consisting of tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, and tetrabutylammonium hydroxide as a guest substance of the clathrate hydrate. The heat storage device according to claim 1, comprising a quaternary ammonium salt.   The heat storage device according to claim 1 or 2, wherein at least one of the pair of electrodes includes copper or silver.   The heat storage device according to any one of claims 1 to 3, wherein the heat storage material includes silver ions when the heat storage material is in a liquid state. A housing,
A heat storage material container containing the heat storage material, wherein a flow path of a heat medium for applying heat to the heat storage material or recovering heat from the heat storage material includes an inner peripheral surface of the housing and the heat storage material. A heat storage material container disposed in the internal space of the housing, so as to be formed between the outer peripheral surface of the material container,
A pair of funnel-shaped end members disposed at both ends of the casing in the direction in which the heat medium flows and having an inner diameter that expands toward the casing;
A pair of rectifying members that are in contact with each of the both ends of the casing and are fixed to the inside of each of the end members, and regulate the flow of the heat medium having a plurality of through holes,
The heat storage device according to any one of claims 1 to 4. Preparing the heat storage device according to any one of claims 1 to 5 in a state where the heat storage material forms the clathrate hydrate;
Increasing the temperature of the heat storage material to decompose the clathrate hydrate;
Cooling the heat storage material to form the clathrate hydrate from the heat storage material in a liquid state, and
In the cooling step, when the heat storage material is in a liquid state and a supercooling state, a voltage is applied to the pair of electrodes to release the supercooling state of the heat storage material and generate the clathrate hydrate. A cooling release step, and a heat recovery step of recovering heat released from the heat storage material in association with release of the supercooled state of the heat storage material.
Thermal storage method.

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