JP2006153433A - Thermal storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal storage device which can be miniaturized, and capable of storing cold and heat. <P>SOLUTION: A thermal storage tank 10 housing a thermal storage material M having potassium dititanate as a main component, and having an electric resistance heating heater 32 and a heat absorber 34h, and a tank 12 housing water W, having a heat absorber 24w, and formed with uneven parts on an inner wall surface 14 are connected by a conduit 46a having opening and closing valves 44a and 44b, and a pressure-reduced and sealed thermal storage tank 10 interior is communicated with a tank 12 interior. When the thermal storage material M occludes water molecules between layers of crystals, the heat absorber 34w recovers latent heat of vaporization dissipated from the water W vaporizing in the tank 12 as cold, and the heat absorber 24h recovers heating of the thermal storage material M in the thermal storage tank 10 as heat. When water molecules are released from the thermal storage material M, the heat absorber 34w recovers latent heat of condensation dissipated from water vapor V condensed in the tank 12 as heat. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat storage device that can collect hot and cold heat and can use hot and cold heat in a timely manner.

In recent years, when environmental problems are actively taken up, the effective use of energy has become a major concern. There are statistics that about 66% of all primary energy consumed in Japan is waste heat and not used, but many of these waste heat is low-grade waste heat and difficult to reuse. Have.
On the other hand, air conditioners, water heaters, boilers, etc. are indispensable devices in homes, offices, factories, etc., and the increase in energy consumption by these devices brings about not only environmental problems but also concerns about stable power supply. Therefore, energy saving measures for these devices are being actively implemented to reduce energy consumption.

In particular, during the summer time around noon when the operating rate of air-conditioning equipment reaches its peak, power consumption increases rapidly and has a great influence on the stable supply of power. It is also. There is an ice heat storage system as a technology for leveling power consumption.
The ice heat storage system creates and stores ice as a cold heat source using cheap nighttime electricity during the summer, and uses the melting latent heat of the stored ice for cooling during the daytime when the air conditioner is operated. I do. Then, during the winter season, warm water as a heat source is created and stored using inexpensive nighttime electric power, and heating is performed using the sensible heat of hot water during the daytime when the air conditioner is operated. However, the ice heat storage system has the disadvantages of large facilities and high initial investment, and, like conventional air conditioners, requires a compressor. In winter, hot water is made from cold water to maintain its temperature. The power consumption is large. Therefore, the power cost reduction achieved by the ice heat storage system in winter is not as good as in summer. Because of these problems, the current penetration rate of ice heat storage systems is only about 1% of the shipments of packaged air conditioners.

  Therefore, in order to solve the problem of power consumption reduction of the ice heat storage system, a technology related to a latent heat storage system using water has been developed. As an example of such a technique, the latent heat storage system proposed in Patent Document 1 has an ice storage tank that evaporates internal water, generates ice by the latent heat of evaporation, and stores cold heat, and a container connected to the ice storage tank. An adsorption unit that contains an adsorbent that adsorbs water vapor from the ice storage tank, and an adsorption unit and an ice storage tank that communicate with each other when the valve is opened between the adsorption unit and the ice storage tank. And an opening / closing valve that shuts off the connection when the valve is closed, and a heating means that heats the adsorbent when the opening / closing valve is closed, and operates the heating means from the adsorbent in the container to the outside of the container. The adsorbent is regenerated by discharging water vapor. In addition, the adsorbent accommodated in the adsorption unit is mainly composed of silica gel, zeolite, or the like.

  In this latent heat storage system, the adsorbent adsorbs water vapor continuously, and the water stored in the ice heat storage tank takes away the latent heat of vaporization and becomes water vapor so that the equilibrium state is maintained. Done. When the adsorbent has adsorbed moisture to the limit of its adsorption capacity, the on-off valve is closed and the adsorbent is heated by heating means, and the water vapor generated from the adsorbent is taken out of the container to regenerate the adsorbent to its original state. Then, cold heat storage is continuously performed by the regenerated adsorbent. Waste heat or the like can be used as the heating means.

  Moreover, the latent heat storage system proposed in Patent Document 2 is connected to an ice storage tank that evaporates internal water and generates ice by the latent heat of evaporation to store cold energy, and an ice storage tank, and receives sunlight. A heat collecting container that collects heat, an adsorbent that is installed in the heat collecting container and adsorbs water vapor from the ice heat storage tank, and connects the heat collecting container and the ice heat storage tank when the heat collecting container collects heat. And when the heat is collected in the heat collection container, the valve is opened between the heat collection container and the ice heat storage tank so that the heat collection container and the ice heat storage tank are connected to each other. And a discharge means for discharging water vapor discharged from the adsorbent in the heat collection container to the outside of the heat collection container.

In this latent heat storage system, cold heat storage is performed in substantially the same manner as proposed in Patent Document 1, and solar heat is used for regeneration of the adsorbent.
Unlike the ice heat storage system, these latent heat storage systems do not use a refrigerator to generate ice, so power consumption is small, and the water vapor generated in the ice heat storage tank using an exhaust means such as a vacuum pump. Need not be discharged to the outside.
JP-A-7-167463 JP-A-7-167466

In the above-described latent heat storage system, the adsorption of water vapor by the adsorbent serves as a driving force for the system, and ice is generated by the latent heat of vaporization when the water stored in the ice heat storage tank evaporates. However, an adsorbent made of silica gel or zeolite has a small amount of water adsorbed per unit volume. For this reason, the production | generation of the ice in an ice thermal storage tank requires a very large quantity of adsorbent, and there exists a problem that a latent-heat thermal storage system enlarges. In addition, since the latent heat storage system stores only cold heat, there is a problem that the application field is limited in practical use.
The present invention solves the above problems, and an object of the present invention is to provide a heat storage device that can be reduced in size, can store cold and heat, and can use large heat and cold in a timely manner.

The present invention adopts the following configuration in order to solve the problem. The heat storage device according to the invention of claim 1 is a potassium dititanate represented by the general formula K ₂ Ti ₂ O _{5 -x} · nH ₂ O (where 0 ≦ x ≦ 1, 0 ≦ n ≦ 2.7). A heat storage tank containing a heat storage material mainly comprising: a water storage tank having a heating means and a heat absorption means; a water tank containing water; a heat absorption means; a conduit connecting the heat storage tank and the water tank and having an on-off valve; And a pressure reducing means configured to be able to depressurize the inside of the heat storage tank and the water tank, and the inside of the heat storage tank and the water tank are reduced to an atmospheric pressure or lower and sealed, and the latent heat of evaporation when water evaporates in the water tank While recovering by the heat absorption means of the water tank as cold heat, open the on-off valve to guide the water vapor from the water tank to the heat storage tank, and the heat of hydration when the heat storage material occludes water molecules between the crystal layers in the heat storage tank as the heat The heat storage material collected by the heat absorption means of the heat storage tank and occluded with water molecules between the crystal layers is heated by the heating means. The water vapor generated from the heated heat storage material is guided to the water tank, and the latent heat of condensation when the water vapor condenses in the water tank is recovered as heat by the heat absorption means of the water tank. Stop heat generation or heat absorption and heat generation or heat absorption in the water tank.

  Potassium dititanate, which is the main component of the heat storage material, generates heat when water molecules are occluded between crystal layers, and absorbs heat when water molecules are detached from the crystal. Like activated alumina and zeolite, potassium dititanate is a solid in the endothermic and exothermic processes and is easy to handle. In addition, compared with activated alumina or zeolite that adsorbs water molecules, potassium dititanate has a weight per unit volume that is twice or more, so the amount of heat stored per unit volume is large. Therefore, when comparing activated alumina or zeolite having the same heat storage amount with potassium dititanate, the potassium dititanate may have a small volume, and the heat storage device can be downsized.

In the crystal structure of potassium dititanate, it is considered that K ⁺ ions are arranged between layers composed of TiO ₅ triangular bipyramids. In such a crystal structure, K ⁺ ions arranged between the layers are easily hydrated to form potassium dititanate hydrate represented by the general formula K ₂ Ti ₂ O _5-x · nH ₂ O. At this time, water molecules are occluded between layers made of TiO ₅ triangular both pyramids so as to be induced by K ⁺ ions. Although the water molecules are occluded and the interval between the layers made of TiO ₅ triangular bipyramids is extended, the crystal structure is maintained. Although there is experimental data, 2.7 is obtained as the maximum value that can take the amount n of H ₂ O.

K ₂ Ti ₂ O _5-x quickly absorbs water molecules in the atmosphere between crystal layers, and produces K ₂ Ti ₂ O _5-x · nH ₂ O. When the produced K ₂ Ti ₂ O _5-x · nH ₂ O is heated to 250 ° C. in the atmosphere of 20 ° C. and 50% relative humidity, it is about 15% of the mass of K ₂ Ti ₂ O _5-x · nH ₂ O. NH ₂ O corresponding to the above is detached, the interval between the layers made of TiO ₅ triangular bipyramids contracts, and returns to K ₂ Ti ₂ O _5-x . This reaction is considered to be a kind of topochemical reaction and is not accompanied by a change in crystal structure. Therefore, potassium dititanate is extremely stable against repeated insertion and removal of water molecules.

20 ° C., 50% relative humidity in the atmosphere, heated n = 2.6 for the _{K 2 Ti 2 O 5-x} · nH 2 O from 30 ° C. at a rate of 10 ° C. / min up to 250 ° C., K ₂ As a result of measuring the endothermic amount when nH ₂ O is desorbed from Ti ₂ O _5-x · nH ₂ O, a value of 306 J / g (= 780 J / cm ³ ) is confirmed, and the endothermic temperature is 30 to 215 ° C. Recognized in the area. Therefore, potassium dititanate functions as a heat storage material in a temperature range of 30 to 215 ° C.

In addition, in the crystal structure of potassium dititanate, K ⁺ ions existing between layers of TiO ₅ triangular bipyramids are strongly bonded to water molecules, so even if the temperature is lower than 130 ° C., the water vapor pressure and temperature of the atmosphere fluctuate. The water molecules are continuously occluded between the crystal layers at a substantially constant rate, and heat is generated. Therefore, unlike activated alumina or zeolite, potassium dititanate is not significantly affected by changes in atmospheric water vapor pressure or temperature.

  When the inside of the heat storage tank and the water tank are reduced to below atmospheric pressure with a vacuum pump or the like and sealed, and the open / close valve of the conduit is opened, the water quickly vaporizes into the water vapor until the saturated water vapor pressure is reached. It flows in the heat storage tank. Since the heat storage material in the heat storage tank occludes water molecules between the crystal layers at a high speed, vaporization of water is further promoted in order to maintain the saturated water vapor pressure in the heat storage tank and the water tank. Until the inside of the heat storage tank and the water tank reach the saturated water vapor pressure, the water absorbs the latent heat of vaporization, and the latent heat of vaporization is used as a cold heat and is recovered by the heat absorption means of the water tank. On the other hand, in the heat storage tank, the water storage material generates heat by releasing water molecules between the crystal layers and releases the heat, and the heat absorption means of the heat storage tank collects the released heat. Potassium dititanate, which is the main component of the heat storage material, stops heating when a maximum of 2.7 moles of water molecules per mole of potassium dititanate are occluded between crystal layers.

Next, when the heating means of the heat storage tank heats the heat storage material that has occluded water molecules, the water molecules in the potassium dititanate crystal become water vapor and leave the crystal, and the separated water vapor is discharged from the heat storage tank into the conduit. Flows through the water tank.
Therefore, as long as heat for heating the heat storage material is introduced from the outside into the heat storage device by the heating means, cold heat and warm heat can be obtained, and furthermore, cold heat and warm heat can be repeatedly released.

A heat storage device according to a second aspect of the present invention is the heat storage device according to the first aspect, wherein the inner wall surface of the aquarium is not smooth but has irregularities, and the water vapor that has flowed into the aquarium by the irregularities is capillary condensed. It becomes water. The water vapor that condenses in the capillaries releases latent heat of condensation, and the heat absorption means of the water tank collects the latent heat of condensation as heat. Capacitive condensation of water vapor is caused by the strong adhesion of water condensed in the capillaries in the concave and convex recesses on the inner wall surface of the aquarium, and the vapor pressure of water adhering to the recesses is smaller than the vapor pressure of the water stored in the bottom of the aquarium. And the latent heat of condensation is released efficiently.
Examples of the heating means of the heat storage tank include an electric resistance heater, a heating device that uses waste heat such as a water heater and a boiler, and a heating device that uses solar concentrated heat. If an appropriate heating means is selected and used according to the operating time zone of the heat storage device, the cost can be reduced.

A heat storage device according to a third aspect of the present invention is the heat storage device according to the second aspect, wherein the non-smooth shape is a fine linear groove in the vertical direction formed on the inner wall surface of the water tank.
If a fine linear groove in the vertical direction is formed on the inner wall surface of the aquarium, the water generated by capillary condensation from water vapor in the groove on the inner wall surface will flow along the groove and smoothly flow to the bottom of the aquarium and be removed from the groove. Capillary condensation is promoted. Further, since the groove is fine, the specific surface area of the inner wall is increased, and the capillary condensation of water vapor is efficiently performed. The width of the groove is, for example, about 0.1 to 2 mm. The cross-sectional shape of the groove is not particularly limited, and examples of the cross-sectional shape of the groove include a triangular shape, a quadrangular shape, a semicircular shape, and an elliptical shape.

A heat storage device according to a fourth aspect of the present invention is the heat storage device according to the second aspect, wherein the non-smooth shape is in close contact with the inner wall surface of the water tank and is formed of a copper wire or an aluminum wire subjected to corrosion resistance treatment on the surface. Net.
Since copper has a high thermal conductivity, water vapor tends to be capillary condensed on a net formed of copper wire. Further, when the diameter of the copper wire forming the net is reduced, the specific surface area of the net increases, and water vapor tends to condense in the capillaries. However, considering the strength of the net, the diameter of the copper wire forming the net is preferably set to 0.01 to 0.3 mm, for example.

Since aluminum also has a high thermal conductivity, water vapor tends to be condensed on the net formed by the aluminum wire. By subjecting the surface of the aluminum wire forming the net to corrosion resistance, the net can be prevented from being corroded by water. Gold and silver having a high thermal conductivity are expensive, and the cost of the net can be reduced by forming the net with a copper wire or an aluminum wire. The copper wire or aluminum wire may be made of a copper or aluminum alloy as a main component.
The net shape may be any shape as long as it can form a minute space between the nets and has a large surface area. Examples of the shape of the net include plain weave, twill weave, plain tatami weave, twill tatami weave, lotus weave, and the like, and a structure in which punching metal is laminated may be used.

The heat storage device according to the invention of claim 5 is the heat storage device according to claim 2, wherein the water tank is made of aluminum, and the inner wall surface of the water tank is electrolytically etched and then anodized to form a non-smooth shape. .
Aluminum that has been anodized after electrolytic etching is called anodized alumina or anodized porous alumina, and its foil is used as an electrode of an aluminum electrolytic capacitor. By subjecting aluminum to electrolytic etching, pores are formed on the surface of the aluminum. These pores form a honeycomb structure in which cylindrical cells orthogonal to the surface are regularly arranged in a hexagonal manner, and have a large specific surface area. The pore diameter of the pores formed by electrolytic etching varies depending on the electrolytic etching conditions, but is generally about 0.1 μm. When electrolytic etching is performed on an aluminum water tank, an aqueous solution such as HCl, NaCl, NH ₄ Cl, or ClCH ₂ COOH is placed in the water tank, the water tank is used as an anode, and the cathode is placed in the aqueous solution. Apply current.

When anodizing is applied to aluminum that has been subjected to electrolytic etching, the surface of a cylindrical cell on the surface of the aluminum is covered with alumina, and corrosion of the aluminum surface with water can be suppressed. When anodizing is performed after electrolytic etching is performed on an aluminum water tank, boiling water is put into the water tank, and Al ₂ O ₃ .mH ₂ O (where 1.0 ≦ m ≦ 2.7) is added. After forming the pseudo boehmite film, the water in the water tank is discharged, and then an aqueous ammonium borate solution or an aqueous ammonium phosphate solution is placed in the water tank, the water tank is used as the anode, the cathode is placed in the aqueous solution, and a direct current of about 600 V between the two electrodes. Apply voltage.
When the water tank is made of aluminum, the inner wall surface of the water tank is subjected to electrolytic etching, and further subjected to an anodic oxidation treatment, water vapor is easily condensed on the inner wall surface of the water tank, and corrosion of the inner wall surface of the water tank can be prevented.

  A heat storage device according to a sixth aspect of the present invention is the heat storage device according to any one of the first to fifth aspects, wherein when the water tank is filled with a fabric made of fibers of less than 0.01 tex, water vapor is capillary on the inner wall of the water tank. When condensing, the generated water is quickly taken up from the inner wall of the aquarium, so that capillary condensation can be promoted, and as a result, the recovery rate of condensation latent heat is improved. Furthermore, even if the heat storage device or the water tank is inclined due to high water retention, water can be prevented from flowing into the heat storage tank, and as a result, decomposition of potassium dititanate which is the main component of the heat storage material can be prevented.

Fibers with a diameter of less than 0.01 tex are called ultra-fine fibers. If the cross section of the fiber is assumed to be a perfect circle, it corresponds to a fiber with a diameter of about 5 μm or less. Since it has a surface area, it also has high water retention. Most of the ultrafine fibers have a complicated cross-sectional shape, and can be divided into a split type and a sea-island type from the cross-sectional shape. The thickness of the fiber is expressed in terms of fineness, and the expression method is tex as a unit introduced to unify the notation of different thickness for each material.
tex is expressed by equation (1).
tex (tex) = 1000 x W (g) / L (m) Equation (1)
L: Yarn length (m), W: Yarn weight (g).
A highly water-absorbing resin is generally used as a material that absorbs water quickly and has high water retention. However, the highly water-absorbent resin does not have the property of quickly releasing the absorbed water, and the operation using the evaporation heat of water in the water tank of the heat storage device of the present invention does not function sufficiently.
In addition, the cloth produced with the fiber below 0.01 tex can take the form of a woven fabric or a nonwoven fabric.

  Since the present invention is a heat storage device as described above, it can be miniaturized, can store cold and warm heat, and can use warm and cold timely.

The best mode for carrying out the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a heat storage device according to the present invention, FIG. 2 is an explanatory diagram of a water tank, (i) is a structural diagram of the water tank, and (ii) is a cross-sectional view taken along line II of (i).
The heat storage device 1 includes a heat storage tank 10, a water tank 12, heat exchangers 24h and 24w, a vacuum pump 26, circulation pumps 28h and 28w, storage tanks 30h and 30w, and a conduit 46.

In the heat storage tank 10, the main component is potassium dititanate represented by the general formula K ₂ Ti ₂ O _5-x · nH ₂ O (where 0 ≦ x ≦ 1, 0 ≦ n ≦ 2.7). The heat storage material M to be stored is accommodated. The heat storage tank 10 includes an electric resistance heater 32 capable of controlling the temperature in a range up to 250 ° C., is configured to be able to heat the heat storage material M, and is a thermometer (not shown) installed in the heat storage tank 10. Thus, the temperature in the heat storage tank 10 can be measured. Further, the conduit 36h of the heat absorber 34h is disposed in close contact with the heat storage tank 10 and spirally disposed.

  A storage tank 30 h, a circulation pump 28 h, and a heat exchanger 24 h are arranged adjacent to the heat storage tank 10. The storage tank 30h, the circulation pump 28h, the heat exchanger 24h, and the conduit 36h of the heat absorber 34h are connected to each other by piping. The storage tank 30h is connected to the suction side of the circulation pump 28h, the discharge side of the circulation pump 28h is connected to the inlet side of the conduit 36h of the heat absorber 34h via the heat exchanger 24h, and the outlet side of the conduit 36h of the heat absorber 34h is It is connected to the storage tank 30h.

The on-off valve 38a is arranged in a pipe between the discharge side of the circulation pump 28h and the heat exchanger 24h, and the on-off valves 38b and 38c are pipes between the heat exchanger 24h and the inlet side of the conduit 36h of the heat absorber 34h. The on-off valve 38d is arranged in the piping between the outlet side of the conduit 36h of the heat absorber 34h and the storage tank 30h.
The pipe branches from between the discharge side of the circulation pump 28h and the on-off valve 38a and is connected between the on-off valve 38b and the on-off valve 38c, and the on-off valves 38e and 38f are arranged in this branched pipe. . Another pipe branches from between the on-off valve 38b and the on-off valve 38c and is connected between the on-off valve 38d and the storage tank 30h, and the on-off valves 38g and 38i are arranged in this branched pipe.

A heat medium T is stored in the storage tank 30h.
The heat exchanger 24h is configured to be able to transfer heat from the heat medium T flowing on the primary side to the water flowing on the secondary side.
Water W is accommodated in the bottom of the water tank 12, and the upper part of the water tank 12 is a space 13. However, in the case where a cloth made of fibers of less than 0.01 tex is filled in the water tank, part or all of the water W is retained by the cloth, and the space 13 is also occupied by the cloth. On the inner wall surface 14 of the water tank 12, a groove 16 that is continuous in the vertical direction and has a width of 0.1 to 2 mm is formed. Further, the temperature in the space 13 can be measured by a thermometer (not shown) installed in the water tank 12, and the conduit 36 w of the heat absorber 34 w is arranged in a spiral manner in close contact with the water tank 12. Yes.

  A storage tank 30w, a circulation pump 28w, and a heat exchanger 24w are installed adjacent to the water tank 12. The storage tank 30w, the circulation pump 28w, the heat exchanger 24w and the conduit 36w of the heat absorber 34w are connected to each other by piping, the storage tank 30w is connected to the suction side of the circulation pump 28w, and the discharge side of the circulation pump 28w is the heat exchanger. 24w is connected to the inlet side of the conduit 36w of the heat absorber 34w, and the outlet side of the conduit 36w of the heat absorber 34w is connected to the storage tank 30w.

The on-off valve 40a is disposed in a pipe between the discharge side of the circulation pump 28w and the heat exchanger 24w, and the on-off valves 40b and 40c are pipes between the heat exchanger 24w and the inlet side of the conduit 36w of the heat absorber 34w. The on-off valve 40d is arranged in the piping between the outlet side of the conduit 36w of the heat absorber 34w and the storage tank 30w.
A pipe branches from between the discharge side of the circulation pump 28w and the on-off valve 40a and is connected between the on-off valve 40b and the on-off valve 40c, and the on-off valves 40e, 40f are arranged in this branched pipe. . Another pipe branches from between the on-off valve 40b and the on-off valve 40c and is connected between the on-off valve 40d and the storage tank 30w, and the on-off valves 40g and 40i are arranged in this branched pipe.

A heat medium T is stored in the storage tank 30w.
The heat exchanger 24w is configured to be able to transmit cold heat from the heat medium T flowing on the primary side to the water flowing on the secondary side.
The pipe branches from the outlet side of the conduit 36w of the heat absorber 34w and the on-off valve 40d and is connected between the on-off valve 38d and the storage tank 30h, and the on-off valve 42a is arranged in this branched pipe. Yes. Another pipe branches from between the on-off valve 38b and the on-off valve 38c and is connected between the inlet side of the conduit 36w of the heat absorber 34w and the on-off valve 40c, and the on-off valves 42b and 42c branch off. It is arranged in the piping.
A conduit 46a is connected to the heat storage tank 10 from the space 13 in the upper part of the water tank 12, and open / close valves 44a and 44b are arranged in the conduit 46a. A conduit 46b branches from the conduit 46a between the on-off valve 44a and the on-off valve 44b and is connected to the vacuum pump 26, and an on-off valve 44c is disposed in the conduit 46b.

Next, the operation of the heat storage device 1 will be described.
The heat storage device 1 operates by continuously repeating the two processes of the heat recovery process and the heat / cool recovery process. The heat recovery step is a step of recovering heat from the heat storage device 1, and water molecules are detached from the heat storage material M. On the other hand, the hot / cold heat recovery step is a step of recovering both hot heat and cold heat from the heat storage device 1, and water molecules are occluded between the crystal layers of the heat storage material M. In other words, the operation cycle of the heat storage device 1 including the repetition of the heat recovery process and the heat / cool recovery process correlates with the transfer of water molecules to the heat storage material M.

Both the heat recovery process and the heat / cool recovery process can be selected as the start-up state of the heat storage device 1, but potassium dititanate, which is the main component of the heat storage material M, produces water molecules when manufactured under general conditions. Since it is produced with K ₂ Ti ₂ O _5−X · nH ₂ O (where 0 ≦ X ≦ 1, n≈2.7) occluded between the crystal layers, the heat recovery process is performed as a starting state. Is suitable. Therefore, the case where a heat recovery process is performed as a state at the time of starting will be described here.

First, the on-off valves 44a and 44c are opened, the on-off valve 44b is closed, and the vacuum pump 26 is driven to depressurize the water tank 12. When the inside of the water tank 12 reaches a predetermined degree of vacuum, the on-off valve 44a is closed, the on-off valve 44b is opened, and the inside of the heat storage tank 10 is decompressed. When the inside of the heat storage tank 10 reaches a predetermined degree of vacuum, the on-off valves 44b and 44c are closed and the vacuum pump 26 is stopped. At this stage, the heat storage material M in the heat storage tank 10 occludes water molecules between the crystal layers as much as possible, and K ₂ Ti ₂ O _5-x · 2.7H ₂ O (where 0 ≦ x ≦ 1 It is preferable that

  Next, the on-off valves 44 a and 44 b are opened, the heat storage tank 10 and the water tank 12 are communicated, and the heat storage material M is heated to 250 ° C. by the electric resistance heater 32. Water molecules are detached from the heat storage material M to become water vapor V, and the water vapor V flows from the heat storage tank 10 to the space 13 in the water tank 12. The water vapor V that has flowed into the space 13 condenses in the capillaries in the grooves 16 on the inner wall surface 14 of the water tank 12 to become water W, and the water W that has undergone capillary condensate flows through the grooves 16 and is discharged to the bottom of the water tank 12. However, when filling the fabric made of fibers of less than 0.01 tex in the aquarium 12, water is absorbed into the fabric while part or all of the water W flows through the groove 16 to the bottom of the aquarium 12, Water W is quickly removed from the groove 16. Condensation latent heat is released as heat from the steam V condensed in the capillary into the water tank 12, and the released heat is transmitted to the conduit 36 w of the heat absorber 34 w in close contact with the water tank 12.

  When taking out the warm heat released into the water tank 12 as hot water immediately, the on-off valves 38a, 38b, 42a, 42b, 42c are opened, the on-off valves 38c, 38d, 38e, 38f, 38g, 38i, 40c, 40d are closed, A first circulation path of the heat medium T is formed. The first circulation path starts from the storage tank 30h through the circulation pump 28h, the open / close valve 38a, the heat exchanger 24h, the open / close valves 38b, 42b, 42c, the conduit 36w of the heat absorber 34w, and the open / close valve 42a in order. This is a route back to 30h. When the first circulation path is formed, the circulation pump 28h is driven, and the heat medium T is circulated through the first circulation path.

Warm heat is transmitted from the water vapor V condensed in the water tank 12 to the conduit 36w of the heat absorber 34w, and further transmitted from the conduit 36w to the heat medium T flowing through the conduit 36w. The heat medium T to which the warm heat is transmitted rises in temperature, the heated heat medium T flows to the primary side of the heat exchanger 24h, and the water on the secondary side of the heat exchanger 24h is transmitted the warm heat from the heat medium T. It becomes warm water, and the heat is taken out from the heat exchanger 24h as warm water.
When the detachment of water molecules from the heat storage material M is completed, the heat generated in the water tank 12 is converged by the water vapor V that releases the latent heat of condensation, and the temperature in the water tank 12 gradually decreases. When the temperature drop in the water tank 12 is detected by the thermometer of the water tank 12, the on-off valves 44a and 44b are closed and the circulation pump 28h is stopped.

  When the hot heat released into the water tank 12 is not immediately taken out as hot water but is taken out as hot water when necessary, the on-off valves 38e, 38f, 42a, 42b, 42c are opened and the on-off valves 38a, 38b, 38c, 38d, 38g are opened. , 38i, 40c, 40d are closed, and the second circulation path of the heat medium T is formed. The second circulation path is a path that returns from the storage tank 30h to the storage tank 30h through the circulation pump 28h, the open / close valves 38e, 38f, 42b, and 42c, the conduit 36w of the heat absorber 34w, and the open / close valve 42a in order. When the second circulation path is formed, the circulation pump 28h is driven, and the heat medium T is circulated through the second circulation path.

  Warm heat is transmitted from the steam V condensed in the water tank 12 to the conduit 36w of the heat absorber 34w, and further transmitted from the conduit 36w to the heat medium T flowing through the conduit 36w, so that the temperature of the heat medium T rises. Since the heat medium T circulating in the second circulation path does not pass through the heat exchanger 24h, the heat medium T stores the heat and is stored in the storage tank 30h while maintaining a high temperature. However, if the heat generated in the water tank 12 converges and a temperature drop in the water tank 12 is detected, the on-off valves 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38i, 40c, 40d, 42a, 42b, 42c Is closed, the circulation pump 28h is stopped, and the heat medium T is stored in the storage tank 30h.

  When taking out the heat stored in the heat medium T of the storage tank 30h, the on-off valves 38a, 38b, 38g, 38i are opened, the on-off valves 38c, 38d, 38e, 38f, 42a, 42b are closed, 3 circulation paths are formed. The third circulation path is a path that returns from the storage tank 30h to the storage tank 30h through the circulation pump 28h, the on-off valve 38a, the heat exchanger 24h, and the on-off valves 38b, 38g, and 38i in order. When the third circulation path is formed, the circulation pump 28h is driven, and the heat medium T is circulated through the third circulation path.

The heat medium T storing the heat flows from the storage tank 30h to the primary side of the heat exchanger 24h, the water on the secondary side of the heat exchanger 24h is transferred to the heat medium T to become hot water, and the heat is converted into the heat exchanger. It is taken out as hot water from 24h.
The above is the heat recovery process of the heat storage device 1.
After finishing the heat recovery process, the process proceeds to the heat recovery process.

At the stage where the heat recovery process is finished, the heat storage material M in the heat storage tank 10 is almost K ₂ Ti ₂ O _5-X (where 0 ≦ X ≦ 1) due to the separation of water molecules.
Next, the on-off valves 44a and 44b are opened from a state in which all the on-off valves are closed, and the inside of the heat storage tank 10 and the inside of the water tank 12 are communicated. The heat storage material M is approximately K ₂ Ti ₂ O _5-X (where 0 ≦ X ≦ 1, so water molecules are occluded between the crystal layers, and K ₂ Ti ₂ O _5-X · 2.7H _{2 is} stored. The reaction to generate O (however, 0 ≦ X ≦ 1) starts.The water vapor pressure in the heat storage tank 10 decreases momentarily, but the water W in the water tank 12 vaporizes in order to maintain an equilibrium state. Thus, it becomes steam V in the space 13. When the water W is vaporized, the latent heat of vaporization is absorbed, and the latent heat of vaporization is transmitted as a cold heat to the conduit 36w of the heat absorber 34w that is in close contact with the water tank 12.

  The steam V flows from the space 13 in the water tank 12 into the heat storage tank 10 and contacts the heat storage material M in the heat storage tank 10. However, in the case where the water tank 12 is filled with a cloth made of fibers of less than 0.01 tex, the space 13 is also occupied by the cloth. When the heat storage material M occludes water molecules between the crystal layers, it generates heat, and heat is released from the heat storage material M into the heat storage tank 10, and the released heat is transmitted to the conduit 36h of the heat absorber 34h that is in close contact with the heat storage tank 10. Is done.

  When the cold heat released in the water tank 12 is immediately taken out as cold water and the hot heat released in the heat storage tank 10 is taken out as hot water immediately, the on-off valves 40a, 40b, 40c, 40d are opened, and the on-off valves 40e, 40f, 40g, 40i, 42a, 42c are closed to form the fourth circulation path of the heat medium T, and the on-off valves 38a, 38b, 38c, 38d are opened, and the on-off valves 38e, 38f, 38g, 38i, 42b are closed. Thus, the fifth circulation path of the heat medium T is formed. The fourth circulation path goes from the storage tank 30w to the storage tank 30w through the circulation pump 28w, the on-off valve 40a, the heat exchanger 24w, the on-off valves 40b and 40c, the conduit 36w of the heat absorber 34w, and the on-off valve 40d in order. The return path is the fifth circulation path, which passes from the storage tank 30h through the circulation pump 28h, the on-off valve 38a, the heat exchanger 24h, the on-off valves 38b and 38c, the conduit 36h of the heat absorber 34h, and the on-off valve 38d in order. This is a path that returns to the storage tank 30h. When the fourth circulation path and the fifth circulation path are formed, the circulation pumps 28w and 28h are driven, and the heat medium T is circulated through the fourth circulation path and the fifth circulation path, respectively.

  Cold heat is transmitted from the vapor V vaporized in the water tank 12 to the conduit 36w of the heat absorber 34w, and further transmitted from the conduit 36w to the heat medium T flowing through the conduit 36w. The heat medium T to which the cold heat has been transmitted falls, and the heat medium T having been cooled flows to the primary side of the heat exchanger 24w, and the water on the secondary side of the heat exchanger 24w is transferred with the cold heat from the heat medium T to become cold water. The cold heat is taken out as cold water from the heat exchanger 24w.

Further, the heat is transmitted from the heat storage material M that generates heat in the heat storage tank 10 to the conduit 36h of the heat absorber 34h, and further transmitted from the conduit 36h to the heat medium T flowing through the conduit 36h. The heat medium T to which the warm heat is transmitted rises in temperature, the heated heat medium T flows to the primary side of the heat exchanger 24h, and the water on the secondary side of the heat exchanger 24h is transmitted the warm heat from the heat medium T. It becomes warm water, and the heat is taken out from the heat exchanger 24h as warm water.
When the occlusion of water molecules between the layers of the crystal of the heat storage material M is completed, the heat generation from the heat storage material M converges in the heat storage tank 10, and the temperature in the heat storage tank 10 gradually decreases. When the temperature drop in the heat storage tank 10 is detected by the thermometer of the heat storage tank 10, the on-off valves 44a and 44b are closed and the circulation pumps 28w and 28h are stopped.

  When the cold heat released in the water tank 12 is not immediately taken out as cold water but is taken out as cold water when necessary, the on-off valves 40c, 40d, 40e, 40f are opened and the on-off valves 40a, 40b, 40g, 40i, 42a, 42c are opened. Is closed to form the sixth circulation path of the heat medium T. The sixth circulation path is a path that returns from the storage tank 30w to the storage tank 30w through the circulation pump 28w, the open / close valves 40e, 40f, and 40c, the conduit 36w of the heat absorber 34w, and the open / close valve 40d in order. When the sixth circulation path is formed, the circulation pump 28w is driven, and the heat medium T is circulated through the sixth circulation path.

Cold heat is transmitted from the water W vaporized in the water tank 12 to the conduit 36w of the heat absorber 34w, and further transmitted from the conduit 36w to the heat medium T flowing through the conduit 36w, so that the temperature of the heat medium T drops. Since the heat medium T circulating in the sixth circulation path does not pass through the heat exchanger 24w, the heat medium T stores the cold heat and is stored in the storage tank 30w while being kept at a low temperature.
When the cold stored in the heat medium T of the storage tank 30w is taken out, the on-off valves 40a, 40b, 40g, 40i are opened, the on-off valves 40c, 40d, 40e, 40f are closed, and the seventh circulation path of the heat medium T Form. The seventh circulation path is a path that returns from the storage tank 30w to the storage tank 30w through the circulation pump 28w, the open / close valve 40a, the heat exchanger 24w, the open / close valves 40b, 40g, and 40i in order. When the seventh circulation path is formed, the circulation pump 28w is driven, and the heat medium T is circulated through the seventh circulation path.

The heat medium T storing cold heat flows from the storage tank 30w to the primary side of the heat exchanger 24w, the water on the secondary side of the heat exchanger 24w is transferred with cold heat from the heat medium T to become cold water, and the cold heat is converted into the heat exchanger. It is taken out as cold water from 24w. However, in the heat storage tank _{10 K 2 Ti 2 O 5-} X ( provided that, 0 ≦ X ≦ 1) from _{K 2 Ti 2 O 5-X} · 2.7H 2 O ( provided that, 0 ≦ X ≦ 1) is generated When the reaction is completed, the vaporization of the water W stops, and when the temperature rise in the water tank 12 is detected, the on-off valves 40a, 40b, 40c, 40d, 40e, 40f, 40g, 40i are closed, and the circulation pump 28h is stopped. The heat medium T is stored in the storage tank 30w.

  When the hot heat released in the heat storage tank 10 is not immediately taken out as hot water but is taken out as hot water when necessary, the on-off valves 38c, 38d, 38e, 38f are opened, and the on-off valves 38a, 38b, 38g, 38i, 42a, 42b is closed and the 8th circulation path of the heat carrier T is formed. The eighth circulation path is a path that returns from the storage tank 30h to the storage tank 30h through the circulation pump 28h, the open / close valves 38e, 38f, and 38c, the conduit 36h of the heat absorber 34h, and the open / close valve 38d in order. When the eighth circulation path is formed, the circulation pump 28h is driven, and the heat medium T is circulated through the eighth circulation path.

Warm heat is transmitted from the heat storage material M that generates heat in the heat storage tank 10 to the conduit 36h of the heat absorber 34h, and further transmitted from the conduit 36h to the heat medium T flowing through the conduit 36h, so that the temperature of the heat medium T rises. Since the heat medium T circulating in the eighth circulation path does not pass through the heat exchanger 24h, the heat medium T stores the heat and is stored in the storage tank 30h while maintaining a high temperature.
When the heat stored in the heat medium T of the storage tank 30h is taken out, the above-described third circulation path is formed, the circulation pump 28h is driven, and the heat medium T is circulated through the third circulation path.

The heat medium T storing the heat flows from the storage tank 30h to the primary side of the heat exchanger 24h, the water on the secondary side of the heat exchanger 24h is transferred to the heat medium T to become hot water, and the heat is converted into the heat exchanger. It is taken out as hot water from 24h. However, in the heat storage tank _{10 K 2 Ti 2 O 5-} X ( provided that, 0 ≦ X ≦ 1) from _{K 2 Ti 2 O 5-X} · 2.7H 2 O ( provided that, 0 ≦ X ≦ 1) is generated When the temperature reduction in the heat storage tank 10 is detected by the convergence of the reaction to be performed, the on-off valves 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38i, 40c, 40d, 42a, 42b, 42c are closed, and the circulation pump 28h And the heat medium T is stored in the storage tank 30h.

The above is the hot / cold heat recovery process of the heat storage device 1. In this state, the heat storage device 1 completes the operation cycle including the heat recovery process and the heat / cool recovery process. However, when performing heat recovery or heat / cool recovery, the heat storage process is performed again.
In addition, when performing a thermal-cooling-and-recovery process as the state at the time of starting of the thermal storage apparatus 1, the water storage 12 put first into the water tank 12 the water more than the quantity of water which the thermal storage material M occludes between the layers of crystals, and puts into the thermal storage tank 10 As the material M, K ₂ Ti ₂ O _5-X (where 0 ≦ X ≦ 1) is used.

In the present embodiment, the heat exchangers 24h and 24w have water flowing on the secondary side, but the heat exchangers 24h and 24w serve as fan coils, and the heat exchanger 24h takes out hot heat as hot air, and heat exchange is performed. It is also possible to take out cold heat as cold air by the vessel 24w.
In the present embodiment, the electric resistance heater 32 heats the heat storage material M of the heat storage tank 10, but it is also possible to heat the heat storage material M by waste heat or condensed solar heat. However, when heating the heat storage material M at night, it is appropriate to use the electric resistance heater 32 that can use inexpensive nighttime power.

  In the present embodiment, the conduit 36h of the heat absorber 34h is disposed in a spiral manner in close contact with the heat storage tank 10, and the conduit 36w of the heat absorber 34w is disposed in a spiral manner in close contact with the water tank 12. However, the conduits 36h and 36w may be arranged so as to be excellent in heat transfer, and are not limited to the helical arrangement. For example, the conduit 36h is drawn into the heat storage tank 10, and the conduit 36h is arranged on a large number of plate fins so as to ensure a large contact area with the water vapor V. The conduit 36w is drawn into the water tank 12, and the conduit 36w. May be arranged on a large number of plate fins so as to ensure a large contact area with the water vapor V. In this case, since the heat storage tank 10 and the conduit 36h and the water tank 12 and the conduit 36w are the same body, the surface of the conduit 36h and the plate fin are the inner wall of the heat storage tank 10, and the surface of the conduit 36w and the plate fin are the inner wall of the water tank 12. Can be considered.

  In this embodiment, a groove 16 is formed on the inner wall surface 14 of the water tank 12 that is continuous in the vertical direction with a width of 0.1 to 2 mm. Instead, the water tank 12 is formed as shown in FIGS. It is also possible to adopt the configuration shown in the first modification example. In the water tank 12 of Modification 1, a net 18 formed of a copper wire or an aluminum wire subjected to corrosion resistance treatment is attached, and the net 18 is in close contact with the inner wall surface 14 of the water tank 12.

Since the copper wire or aluminum wire forming the net 18 has high thermal conductivity, the water vapor V tends to be capillary condensed on the net of the net 18, and hot or cold heat is efficiently transferred from the net 18 to the conduit 36w of the heat absorber 34w. it can.
The water tank 12 may be configured as shown in Modification 2 of FIGS. 4 (i) and (ii). The water tank 12 of the modification 2 is made of aluminum, and the inner wall surface 14 of the water tank 12 is anodized after electrolytic etching, and the inner wall surface 14 has a large number of pores 20 covered with alumina. Yes.

Aluminum forming the water tank 12 has a high thermal conductivity, and a large number of pores 20 are formed on the inner wall surface 14, so that the water vapor V easily condenses on the inner wall surface 14 of the water tank 12, and heat or Cold heat can be efficiently transmitted to the conduit 36w of the heat absorber 34w.
If the opening / closing valves 44a, 44b are valves such as needle valves, the opening of the opening / closing valves 44a, 44b is adjusted, and the flow rate of water vapor V flowing between the heat storage tank 10 and the water tank 12 is adjusted. Can be controlled. When the flow rate of the water vapor V is controlled, the amount of water vapor V that is capillary condensed in the water tank 12, the amount of water W that is vaporized in the water tank 12, and the amount of water molecules that are occluded between the crystal layers of the heat storage material M in the heat storage tank 10. The amount can be controlled, and the amount of cold and warm heat released per unit time in the water tank 12 and the amount of warm heat released per unit time in the heat storage tank 10 can be controlled. Therefore, it is possible to efficiently extract the cold and warm temperatures of the target temperature.

In all of the present embodiments, when the fabric made of fibers of less than 0.01 tex is filled in the water tank 12 in an amount that can retain the entire amount of water W, not only the recovery efficiency of condensation latent heat is improved, Even if the water tank 12 is inclined, the water W does not flow into the heat storage tank 10, so that the decomposition of potassium dititanate which is the main component of the heat storage material M can be prevented.
Fibers of less than 0.01 tex are often made of organic materials such as polyester and nylon, but they are not deformed or altered by the heat of water vapor, and if they are water resistant, they can be made of inorganic materials such as metals. It doesn't matter.

It is a block diagram of the thermal storage apparatus which concerns on this invention. It is explanatory drawing of a water tank, (i) is a structural diagram of a water tank, (ii) is the II sectional view of (i). It is explanatory drawing of the water tank which concerns on the modification 1, (i) is a structural diagram of a water tank, (ii) is the II-II sectional view taken on the line of (i). It is explanatory drawing of the water tank which concerns on the modification 2, (i) is a structural diagram of a water tank, (ii) is the III-III sectional view taken on the line of (i).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat storage apparatus 10 Thermal storage tank 12 Water tank 13 Upper space in water tank 14 Inner wall surface of water tank 15 Outer wall surface of water tank 16 Groove 18 Net 20 Fine pore 24w, 24h Heat exchanger 26 Vacuum pump 28w, 28h Circulation pump 30h, 30w Storage tank 32 Electric resistance heater 34h, 34w Heat absorber 36h, 36w Heat absorber conduit 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38i On-off valve 40a, 40b, 40c, 40d, 40e, 40f, 40g, 40i On-off valve 42a, 42b, 42c On-off valve 44a, 44b, 44c On-off valve 46a, 46b Pipe M Heat storage material W Water V Steam T Heat medium

Claims (6)

Containing a heat storage material mainly composed of potassium dititanate represented by the general formula K ₂ Ti ₂ O _5-x · nH ₂ O (where 0 ≦ x ≦ 1, 0 ≦ n ≦ 2.7); A heat storage tank having heating means and heat absorption means;
A water tank containing water and having heat absorption means;
A conduit connecting the heat storage tank and the water tank, and having an on-off valve;
A pressure reducing means configured to be able to depressurize the heat storage tank and the water tank;
The inside of the heat storage tank and the water tank are sealed at a reduced pressure below the atmospheric pressure, and the latent heat of evaporation when water evaporates in the water tank is recovered as cold heat by the heat absorption means of the water tank, and the open / close valve is opened to release water vapor from the water tank. Lead to the heat storage tank, and the heat storage material in the heat storage tank collects the heat of hydration when water molecules are occluded between the crystal layers as heat and is recovered by the heat absorption means of the heat storage tank,
Heat storage material that stores water molecules between crystal layers is heated by heating means, water vapor generated from the heated heat storage material is guided to the water tank, and the heat of the water tank is absorbed by the latent heat of condensation when water vapor condenses in the water tank. Recovered by means,
An on-off valve is closed to stop heat generation or heat absorption in the heat storage tank and heat generation or heat absorption in the water tank.   The heat storage device according to claim 1, wherein an inner wall of the water tank has a non-smooth surface.   The heat storage device according to claim 2, wherein the non-smooth shape is a fine linear groove formed in the vertical direction on the inner wall surface of the water tank.   3. The heat storage device according to claim 2, wherein the non-smooth shape is a net made of an aluminum wire that is in close contact with the inner wall surface of the water tank and is subjected to a copper wire or an anti-corrosion treatment on the surface.   The heat storage device according to claim 2, wherein the water tank is made of aluminum, and the non-smooth shape is formed by anodizing after electrolytically etching the inner wall surface of the water tank.   The heat storage device according to any one of claims 1 to 5, wherein the water tank is filled with a cloth made of fibers of less than 0.01 tex.

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