JP2001207163A - Heat storage tank and heat storage apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat storage performance of a heat storage apparatus. SOLUTION: This is a heat-storage tank of such a type that the tank is filled with a latent heat-storage material and the heat exchange between the latent heat-storage material and the heat transfer medium is carried out via the heat transfer wall and is characterized by using, as the latent heat-storage material, a substance that has the ratio of the specific gravity in the liquid phase (dL) to the specific gravity in the solid phase (dS) in the range of 0.5-1.0 (dL/dS), using the heat storage apparatus equipped with the fin structure on the side where the heat transfer wall comes into contact with the latent heat storage material and constituting the fin structure sites and the heat transfer surfaces other than the fin structure sites with a metallic substance where the ionization potential (I1) of the fin structure sites is larger than that (I2) of the heat transfer surfaces other than the fin structure sites. This heat storage tanks are used to constitute the objective heat storage apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage tank using a latent heat storage material and a heat storage device using the same. For more information,
The present invention relates to a heat storage tank characterized by effectively improving the performance as a heat storage device by enlarging a heat transfer surface on a latent heat storage material side, and a heat storage device using the same. A heat storage device using such a heat storage tank includes a regenerative electric water heater using midnight power, a regenerative floor heating system, a heat storage system for an automobile engine in a cold district specification, a factory waste heat recovery system or a regenerative air conditioning system, and a factory process. It is suitably used as a heat storage device such as a cooling system.

[0002]

2. Description of the Related Art A latent heat storage material has a higher heat storage density and a constant phase change temperature than a sensible heat storage material, and has been put to practical use taking advantage of the advantage that the heat extraction temperature is stable. . Ice, sodium sulfate decahydrate, calcium chloride hexahydrate, sodium acetate trihydrate, and the like are known as latent heat storage materials, and are widely used for air conditioning and air conditioning.

On the other hand, systems using hot water supply, solar energy, and waste heat of boilers and automobiles, for which a high phase change temperature is desired, have been studied so far using various latent heat storage materials. Materials having a melting point in the temperature range around 100 ° C. include barium hydroxide octahydrate (melting point 78 ° C., latent heat of fusion 63.8 cal / g) and magnesium nitrate hexahydrate (melting point 89 ° C.) as inorganic hydrates. , Latent heat of fusion
2 cal / g) and the like. However, magnesium nitrate hexahydrate has a problem of corrosiveness to metals, and barium hydroxide octahydrate has not been put to practical use as a heat storage material because it is designated as a deleterious substance in Japan. In addition, paraffin wax, fatty acid, and the like are considered as organic substances, but the heat storage amount per volume is as small as about 35.0 to 45.0 cal / ml, and practical examples are currently limited.

Further, in recent years, it has been found that some sugar alcohols have a large amount of heat storage, and their use as heat storage materials has been studied.
９５95 ° C .; see JP-A-54-65864; erythritol (melting point 119 ° C .; JP-T-63-500946)
And Japanese Patent Application Laid-Open No. 5-32963). Since these are food additives, they have the advantages of being safe, having high latent heat, and having extremely low metal corrosivity. In addition, in the pp. 221 of the 16th Japan Thermophysical Symposium, 1995, it was reported that the addition of pentaerythritol, trimethylolethane and neopentyl glycol to erythritol lowers the phase transition temperature of erythritol by several tens of degrees. Have been.

When the latent heat storage material described above is evaluated as a material, it has an excellent heat storage density and emits latent heat at a constant temperature. However, when incorporated in a heat storage device, the heat storage material that releases latent heat on a heat transfer surface is used. Is solidified and the heat exchange performance with the heat medium gradually decreases as the layers are stacked one after another.As a result, the heat output temperature is not constant and decreases over time. There is a problem that can not be used up.

As a method for solving this problem, there has been reported a research example in which heat transfer fins are soldered in parallel to the length direction of the heat transfer tubes of a shell-and-tube type ice storage tank (35th Japan Heat Transfer Symposium Lecture). Proceedings (889p), Lecture number G322). However, attaching the heat transfer fins by soldering or electric welding not only increases the manufacturing cost of the heat storage tank and thus the heat storage system, but also increases the weight of the device by attaching thick fins, lowers the corrosion resistance of the connection part, and reduces pinholes. The risk of occurrence will increase. In addition, since water has a specific gravity in the solid state (d _S ) smaller than the specific gravity in the liquid state (d _L ) and expands when it solidifies on the heat transfer surface, all the water in the heat storage tank must be solidified. However, when viewed as a heat storage device, there still remains a problem of lowering the heat storage density and lowering the operation efficiency.

As a regenerative ceramic heater (HX-SE5-B, manufactured by Sharp Corp., manufactured in 1996), a paraffin wax is sealed in a plate-like capsule, and a heat storage tank having fins inside and outside is used. There are examples. However, since the fin portion and the heat transfer surface other than the fin portion are formed of the same material, the internal heat storage material is oxidized to generate a corrosion source such as an acidic substance, or the heat storage having an acidic or oxidative property. When a material is used, there is a risk that the capsule body may be corroded. Also, when heat exchange performance that is much larger than that of blast heat transfer is required, heat transfer characteristics are not improved for similar thicker heat transfer fins, although the equipment weight increases, so this is considered a general-purpose technology. I can't.

On the other hand, although attempts have been made gradually to utilize waste heat as unused energy from garbage incineration facilities, gas cooling / heating facilities, thermal power generation facilities, automobiles, etc., most of them are in soil or in the air. It is currently being released. Improving the effective utilization rate of these waste heats is a very important factor in improving crisis situations such as energy depletion and global warming trend that are progressing on a worldwide scale, but exceeding 100 ° C. At present, there is no system capable of efficiently storing or releasing heat and satisfying required safety.

Heretofore, as a heat storage system for the purpose of utilizing waste heat at around 200 ° C., for example, a slurry in which pentaerythritol powder is mixed with a hydrocarbon heat medium having good coexistence is filled in a shell containing a stirrer. A shell and tube type latent heat storage device has been proposed in which a copper spiral tube for passing a heat medium is connected to the slurry (Abe, Y. et al .: Proc. 19th IECEC, p. 1120 (19).
84)). However, this not only reduces the heat storage density, but also makes it impossible to exhibit stable heat storage characteristics due to the instability of the slurry due to the sticking of pentaerythritol, or a large device design due to the use of a large stirring unit. There are problems such as restrictions.

[0010]

The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art by using a latent heat storage material, having a constant heat output, exergy efficiency and operation efficiency. And a heat storage device using the same.

[0011]

Means for Solving the Problems The present inventors have made intensive studies in view of the above problems, and as a result, have stored a specific latent heat storage material,
A heat storage tank of a type in which heat exchange between the latent heat storage material and the heat medium is performed through a heat transfer wall, and has a fin structure on a heat transfer surface,
In addition, according to the heat storage tank formed of the specific metal member, the inventors have found that the heat can be stored at high density, the stored heat can be efficiently supplied, and the long-term reliability of the device can be ensured. . That is, the present invention relates to a heat storage tank of a type in which a latent heat storage material is stored and heat exchange between the latent heat storage material and the heat medium is performed through a heat transfer wall. (d _S) ratio of the specific gravity (d _L) in the liquid phase state (d _L / d _S) is possible to use those in the range of 0.5 to 1.0 relative to the heat transfer wall and latent heat storage material The heat storage tank having a fin structure on the contacting side, and the fin structure portion and the heat transfer surface other than the fin structure portion are both made of metal, and the ionization tendency (I ₁ ) of the fin structure portion is as follows. The present invention relates to a heat storage tank characterized by having a larger ionization tendency (I ₂ ) on a heat transfer surface other than the fin structure portion, and a heat storage device using the same.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The latent heat storage material in the present invention is:
Refers to a heat storage material that utilizes latent heat associated with a phase change between a solid phase and a liquid phase. Also, when the heat storage material is solidified and its volume is larger than the liquid phase, if the heat storage material in the heat storage tank is solidified, stress will be applied to the heat transfer wall and the inner wall of the heat storage tank, causing damage to the device. lead is therefore necessary upper limit of the ratio of the specific gravity (d _L) in liquid state for a specific gravity (d _S) of the solid state of the latent heat storage material (d _L / d _S) is 1.0 or less. Also, if the volumetric shrinkage when the heat storage material is solidified is too large, the liquid level of the heat storage material in the liquid phase drops drastically with the solidification, and the heat storage material cannot uniformly exist on the heat transfer wall. (D _L /
The lower limit of d _S ) is 0.5 or more, preferably 0.7 or more, and particularly preferably 0.8 or more.

As the latent heat storage material of the present invention, any desired material can be used alone or in combination of two or more as needed. Examples of main heat storage materials include 1, 2
-Polyalcohols such as butanediol, 1,4-butanediol, ethylene glycol, diethylene glycol, polyethylene glycol, glycerol, trimethylolethane, and trimethylolpropane; etherified polyalcohols; esterified polyalcohols; paraffin; Preferred are aliphatic hydrocarbons such as polyethylene and polypropylene; organic acid salt hydrates such as sodium acetate hydrate and sodium sulfate hydrate; organic hydrates such as trimethylolethane hydrate; However, a latent heat storage material containing a sugar alcohol is more preferable.

The latent heat storage material containing a sugar alcohol includes a composition containing the sugar alcohol in an amount of usually at least 10% by weight, preferably at least 30% by weight.
This sugar alcohol includes meso-erythritol, l
Erythritols such as erythritol, d-erythritol, dl-erythritol; pentaerythritols such as pentaerythritol and dipentaerythritol; ribitol; xylitol; D-arabitol;
Arabitols such as L-arabitol and DL-arabitol; allitol; darcitol; D-sorbitol;
Mannitols such as L-mannitol; Iditols such as D-iditol and L-iditol; Thalitols such as D-thalitol, L-talitol and DL-thalitol; Persitol; Heptitols such as -D-id-heptitol; D-erythro-D-galacto-octitol; Above all, 100 ° C
As an inexpensive material having a melting point in the vicinity, a high heat storage density, and excellent crystallinity, erythritols are more preferable, and among them, meso-erythritol available as Mitsubishi Chemical Foods Co., Ltd. erythritol is most preferable. You. The heat storage material auxiliary component is not particularly limited as long as it is compatible with the compound serving as the main component and can be eutectic. However, the amount to be used is within a range that does not significantly impair the heat storage material performance of the main component. be able to. In addition, as additives to the heat storage material, a supercooling inhibitor, a heat stabilizer, a flame retardant, a thickener, a gelling agent, an antioxidant, a thermal conductivity improving material, a coloring agent,
Deodorants, fungicides and the like can be used as appropriate.

The heat medium in the present invention refers to a substance that serves as a medium for transferring heat by performing heat exchange with a latent heat storage material via a heat transfer wall. As the heat medium, known materials can be used in an arbitrary composition.Specifically, saturated hydrocarbon oils such as liquid paraffin, aromatic hydrocarbon oils such as halogenated biphenyl, air, Examples include nitrogen, argon, water, steam, and aqueous glycol solutions. Among them, an aqueous heat medium which can use a general-purpose pipe and has a high heat exchange efficiency because of having a high sensible heat density is particularly preferable. In addition, when using as a hot water supply device,
There is also an advantage that the system configuration can be simplified by using water as a heat medium.

The present invention provides a heat storage tank of the type in which the above-described latent heat storage material and a heat medium are used, and heat exchange between the two is performed via a heat transfer wall. A heat storage tank having a fin structure on the side that comes into contact with the material. Here, the heat transfer wall means a solid wall interposed between the heat storage material and the heat medium that transfers heat to and from the heat storage material. As the material of the heat transfer wall, any known metal material may be used, and copper, stainless steel, aluminum, galvanized carbon steel and the like can be arbitrarily used, but aluminum, copper, and stainless steel that are general-purpose and have high corrosion resistance are preferable. There is no particular limitation on the method of forming the heat transfer wall as long as it is a known forming method, but in terms of the simplest and lowest cost achievable method, the fin-tube type heat transfer wall is formed using a press-fitting method. It is preferable to connect the fins to a copper or stainless steel tube.

As the heat exchange method of the heat storage tank, a known known method represented by a finned capsule type, a fin tube type, a fin plate type, or the like can be arbitrarily used according to the purpose, but the simplest method is used. The fin tube type heat exchange method is preferable in terms of a method that can be achieved at low cost. In this fin tube type heat exchange method, when connecting fins of different materials to the heat transfer wall other than the fin part, or when connecting thin fins, the diameter of the hole of the perforated fin is usually slightly larger than the hole diameter. A so-called press-fitting method of applying pressure to penetrate the tube is employed. The fin tube type here is composed of a container for storing the heat storage material and a heat transfer tube, and a single tube or a multi-tube heat transfer tube penetrates the heat storage material to circulate the heat medium inside the heat transfer tube. This means a heat exchange system in which heat exchange is performed, and additional functions such as a heat source unit, a control unit, and a heat insulation unit can be added as necessary.

The fin structure in the heat storage tank of the present invention is as follows.
Any metal fin may be used as long as it is a metal fin connected to the heat transfer wall by a known method, and a rectangular, radially convex, triangular, or radially concave cross-sectional shape can be arbitrarily used. In addition, the fin structure site
It may be in communication with the fin portion forming another heat transfer surface or may be separated. Both the fin structure portion and the heat transfer surface other than the fin structure portion are made of metal, and the ionization tendency (I ₁ ) of the fin structure portion is larger than the ionization tendency (I ₂ ) of the heat transfer surface other than the fin structure portion. I do. I from I _{2
When 1} is small, the presence of an acidic substance or an oxidizing substance in the heat storage material is not preferable because the heat transfer surface other than the fin structure portion is preferentially corroded, and the heat transfer wall is damaged. Here, the ionization tendency refers to a numerical value in pure water at 20 ° C. Further, specific materials of the fin structure portion and the heat transfer surface other than the fin structure portion include aluminum for the fin structure portion and copper or stainless steel for the heat transfer surface other than the fin structure portion.

According to the study of the present inventors, the average overall heat transfer coefficient K relating to heat exchange with the liquid heat medium in the heat storage device is low because the average heat transfer coefficient αp on the heat storage material side is rate-limiting. It has been found that the effect is small even if the average heat transfer coefficient αf on the heat medium side is improved by increasing the flow velocity or enlarging the heat transfer surface on the heat medium side. For a system in which the difference between the heat storage temperature and the heat medium inlet temperature is 200 ° C. or less,
During the release of 50% or more of the heat storage amount, K as an average value for all the heat transfer surfaces including the heat transfer fins is 100.
It is found that the heat transfer fin is 0 kcal / hm ² ° C or less. Under this condition, the required heat transfer fins are thin and function well. Here, the heat storage amount refers to a theoretical heat amount released until the heat storage material heated to the heat storage temperature drops to the same temperature as the heat medium inlet temperature.

As a result of the above study, the average thickness (t _F ) of the fin structure is preferably 0.01 to 0.5.
mm, particularly preferably in the range of 0.05 to 0.3 mm. If t _F is less than 0.01 mm, the strength of the fin portion is insufficient, and not only is the device difficult to manufacture, but also the effect of improving the heat transfer characteristics may be reduced. On the other hand, t _F is 0.5 mm
Beyond that, the increase in equipment weight cannot be ignored,
It is not preferable because the molding conditions are restricted, for example, the fin connection by the press-fitting method becomes difficult. On the other hand, the height H of the fin portion is usually preferably 3 to 150 m.
m, particularly preferably 5-100 mm, most preferably 1
0 to 50 mm. When H is less than 3, the heat exchange efficiency of the device is sufficiently large, so even if a fin portion is provided, the heat exchange efficiency improvement effect is small. On the other hand, when H exceeds 150 mm,
Since the heat exchange efficiency cannot be increased with the thin fins, the fins must be pressure fins, and the weight increase of the apparatus cannot be ignored.

The heat storage tank of the present invention described above has a heat source section,
It is used as a heat storage device including a control unit and a drive unit. As the heat storage device, for example, if it is a hot water supply device, (1) a heat storage tank, (2) a heat source unit for heating the heat storage material, (3) heat storage is terminated by detecting the temperature of the heat storage material, or the heat storage is stopped. A control unit for starting the heating unit and (4) a driving unit for forcibly flowing the heat medium through the heat medium flow path are provided. In the case of a cooling device, (1) a heat storage tank, (2) a heat source unit for cooling the heat storage material, (3) a control unit for detecting the temperature of the heat storage material and terminating the heat storage, and (4) A) a drive unit for forcibly flowing the heat medium through the heat medium flow path.

In the above heat storage device, the method of storing heat in the heat storage material is not limited as long as it is a known heating or cooling method, and waste heat from factories or cogeneration systems, gas burners, solar heat, geothermal, electric heaters, etc. , A refrigerator, a heat pump, an environmental heat source such as deep seawater, or the like can be used as the heat source device. As a specific example of the heat source device,
When a heat source device is provided outside the heat storage tank, the heat medium heated or cooled by the heat source device is driven by a pump, a fan is blown, or is vaporized and transported (= heat is transferred by vaporizing the liquid heat medium and expanding the volume dramatically. A method of transporting the heat medium to the surface and returning the condensed heat medium using natural phenomena such as natural fall or capillary action) to the heat medium flow path in the heat storage tank by driving means. .

When a heat source device is provided inside the heat storage tank, a method of installing an electric heater or a cooling pipe of a refrigerator in the heat storage material may be used. However, a preferred heat source device for the purpose of promoting the use of late-night power is an electric heater or a heat pump when the present invention is used as a hot water supply device. Examples of the electric heater include a direct heating method using a sheathed heater, an induction heating heater, a dielectric heating heater, a far-infrared heating heater, and the like; a sheath heater, an induction heating heater, a dielectric heating heater,
Heat the heating medium using a far-infrared heater, etc.
An indirect heating method in which a heated heat medium is passed through a heat storage tank may be mentioned, and a method using a relatively inexpensive sheath heater is particularly preferable.

The control unit of the heat storage device is a control system used for detecting the temperature of the heat storage material to terminate the heat storage or to start the heat storage, and any known temperature control unit can be used without any limitation. It is possible. More specifically, it refers to a function of making a temperature detection unit such as a thermostat, a thermocouple, a temperature difference meter, and an infrared sensor an essential component, and automatically stopping heat exchange or starting heat storage when a set temperature is reached. Preferably as a temperature detection unit,
Thermostats that are inexpensive and easy to control are mentioned. The location of the temperature control unit is not particularly limited, but is preferably in the latent heat storage material or the outer wall of the heat storage tank.

The drive unit of the heat storage device is a drive system used for forcibly flowing the heat medium through the heat medium flow path, and evaporates a liquid heat medium such as pumps and fans, or steam transport, which is generally known. Known means such as a method of transporting a heat medium to a heat source or a heat transfer surface by expanding the volume dramatically and returning the condensed heat medium using natural phenomena such as natural fall and capillary phenomenon Alternatively, they can be used in combination.

The heat storage device includes a program control unit such as a sequencer, a timer unit such as a calendar timer and a 24-hour timer, a heat source temperature detection unit, a heat source output control unit, a solenoid on-off valve, and a mixing valve, if necessary. , Flow control valve, heat medium flow control unit such as flow meter, auxiliary heat source unit, pseudo load unit ("Heat storage engineering 2" 1st edition, Morikita Publishing Co., Ltd., edited by Nobuhiro Seki, 64p), daily load pattern learning function Needless to say, existing units such as a pressure gauge, an expansion tank, a pressure regulating valve, a drain valve, an automatic heat medium discharging mechanism, a steam condensing tank, an overheating prevention device, a leakage prevention device, and a heat insulating means such as a heat insulating material can be used.

By the way, the latent heat storage material has a feature that it can exchange heat with the highest efficiency at the time of phase change, and has a property that decomposition is promoted and the life is shortened as the temperature is increased. Therefore, when the heat storage device of the present invention is used as a hot water supply device, it is desired that the heat storage temperature be equal to or higher than the melting point (Tm) of the heat storage material and not too high.
The temperature is usually higher in the range of 1 to 100 ° C, preferably 5 to 80 ° C, and the temperature of the heat storage tank inlet of the heat medium in the heat dissipation operation is Tm.
It is more preferable to lower the temperature in the range of usually 1 to 200 ° C, preferably 5 to 150 ° C. Latent heat storage material is (Tm-1)
If not cooled below ℃, solidification is difficult and (Tm−
When the temperature is cooled to 200) ° C. or lower, not only deterioration due to thermal shock is caused but also the average overall heat transfer coefficient K of the device becomes too large, and the effect of improving the heat exchange efficiency becomes difficult to be exhibited with thin heat transfer fins. Absent.

Further, the latent heat storage material has a feature that heat exchange can be performed with the highest efficiency at the time of phase change, and has a property that decomposition is promoted and the life is shortened as the temperature is increased. Therefore, when using the heat storage device of the present invention as a cooling device,
In the heat dissipation operation, it is usually 1 to 1 from the melting point (Tm) of the heat storage material.
200 ° C., preferably in the range of 5 to 80 ° C., and the temperature of the heat storage tank inlet of the heat medium in the heat radiation operation is 1 to 10 ° C. lower than Tm.
It is preferable to increase the temperature in the range of 0 ° C, preferably 5 to 80 ° C. Further, the latent heat storage material is hard to solidify unless cooled to (Tm-1) ° C or lower, and (Tm-200)
It is not preferable that the temperature is cooled to not more than ℃ because not only deterioration due to thermal shock is caused, but also the average overall heat transfer coefficient K of the apparatus becomes too large, and the effect of improving the heat exchange efficiency becomes difficult to appear with thin heat transfer fins.

Hereinafter, specific embodiments of the heat storage device of the present invention as described above will be described in more detail with reference to the drawings. FIG. 1 is a conceptual diagram showing one embodiment of the heat storage device of the present invention.
In FIG. 1, a heat storage device 1 includes a water supply device 2 and a heat storage tank 3 that stores a latent heat storage material and exchanges heat via a heat transfer wall. The water supply device 2 includes a pump 4, a three-way valve 5, a check valve 6,
The water is supplied from the hot water supply port 8 via the heat storage tank 3 and the valve body 7 by driving the pump 4. By the way, the three-way valve 5 is a valve body for adjusting a mixing ratio of water sent to the heat storage tank 3 and water going to the hot water supply port 8 through the bypass pipe 9, and is a hot water or steam water supplied from the hot water supply port 8. Used for temperature control.
Examples of the heat storage device of the present invention include a pressure gauge, a flow meter, an overheating prevention device, an earth leakage prevention device, a temperature sensor, a temperature control device, a heat insulating material, an auxiliary pump, a pressure reducing valve, a heat pump, or a heat storage device. Needless to say, it is necessary to use a buffer tank or the like for absorbing overflow or decrease of the heat medium due to phase transition of the material as necessary.

When heat is stored using the heat storage device, the three-way valve 5 and the valve body 7 are closed, and heat energy is given to the heat storage material by the heat source device 10 carried in the heat storage tank 3. At this time, the temperature of the heat source device 10 is set to (T
(m + 1) ° C to (Tm + 100) ° C. The heat storage material given thermal energy by the heat source device 10 stores latent heat of fusion and sensible heat due to a phase transition from a solid state to a liquid state. In the case where heat is stored while water as a heat medium is present in the pipe 11 in the heat storage tank 3, the pressure in the pipe 11 is increased or reduced. Also, draining the water inside the pipe 11 before starting the heat storage is one safety measure.

When the heat energy stored in the heat storage tank 3 is used, the flow path between the check valve 6 of the three-way valve 5 and the pump 4 and the valve body 7 are opened, and when the pump 4 is driven, water is discharged. Water is supplied from the water supply device to the heat storage tank 3 via the pump 4, the three-way valve 5, and the check valve 6. At this time, the temperature of the water is (Tm-200
C) to (Tm-1C). The water heated by the heat storage material in the heat storage tank 3 is supplied as hot water or steam water from a hot water supply port 8 via a valve body 7. On the other hand, the heat storage material that has released the latent heat transforms to a solid phase.
The water temperature at the hot water supply port can be adjusted by adjusting the three-way valve 5 to adjust the mixing ratio of the water heated in the heat storage tank 3 and the water that has passed through the bypass pipe 9.
If necessary, an auxiliary heat source (such as a heat pump or an electric heater) may be added between the hot water supply port 8 and the valve body 7 to increase the hot water supply temperature.

FIG. 2 is a conceptual diagram showing one embodiment of the heat storage device of the present invention. In FIG. 2, the heat storage device 17 includes a water supply device 2, a heat storage tank 3 that stores a heat storage material and exchanges heat via a heat transfer wall, and a heat source device 18. The water supply device 2
The pump 4 is connected to the heat storage tank 3 via the three-way valve 5 and the check valve 6. By driving the pump 4, the hot water is supplied from the hot water supply port 8 via the heat storage tank 3, the heat source device 18, and the valve element 19. Water is supplied. On the other hand, the heat source device 18 is disposed between the heat storage tank 3 and the branch portion 20, and includes a valve 21, a pump 22, and a valve 2.
3. The heat source device 18 is configured to form a loop through the branch portion 20 and to drive the pump 22
Is supplied to the heat storage tank 3 to heat the heat storage material. The three-way valve 5 is a valve body for adjusting a mixing ratio of water sent to the heat storage tank 3 through the check valve 6 and water flowing to the hot water supply port 8 through the bypass pipe 9. It is used for controlling the temperature of hot water or steam water. Examples of the heat storage device of the present invention include a pressure gauge, a flow meter, an overheating prevention device, an earth leakage prevention device, a temperature sensor, a temperature control device, a heat insulating material, an auxiliary pump, a pressure reducing valve, a heat pump, or a heat storage device. Needless to say, it is necessary to use a buffer tank or the like for absorbing overflow or decrease of the heat medium due to phase transition of the material as necessary.

When heat is stored using the heat storage device, the three-way valve 5, the valve body 19 is closed, the valve bodies 21 and 23 are opened, and the pump 22 is driven. , Enters the heat storage tank 3 and transmits heat energy to the heat storage material via the heat transfer wall. At this time, the temperature of the heat source device 18 is (Tm + 1) ° C. to (Tm + 100) by the temperature controller.
It is controlled in the range of ° C. The heat storage material given thermal energy by the heat source device 18 stores latent heat of fusion and sensible heat due to a phase transition from a solid state to a liquid state.
The water that has been cooled by heating the heat storage material is heated again by the heat source device 18 via the valve 21, the pump 22, and the valve 23. Although the internal pressure of the pipe 11 may be reduced or increased due to its structure, the pressure can be reduced by the pressure control valve 12. A buffer tank 24 is provided at the end of the pressure control valve.

When utilizing the heat energy stored in the heat storage tank 3, the flow path between the check valve 6 of the three-way valve 5 and the pump 3 and the valve body 19 are opened, and the valve bodies 21 and 23 are closed. When the pump 3 is driven, water is supplied from the water supply device 2 to the heat storage tank 3 via the pump 4, the three-way valve 5, and the check valve 6. At this time, the temperature of the water is controlled in the range of (Tm-200C) to (Tm-1C). The water heated by the heat storage material in the heat storage tank 3 is supplied as hot water or steam water from the hot water supply port 8 via the heat source device 18 and the valve body 19. On the other hand, the heat storage material that has released the latent heat transforms to a solid phase. If the water temperature of the hot water supply port 8 is too high, it can be adjusted by adjusting the three-way valve 5 to adjust the mixing ratio of the water heated in the heat storage tank 3 and the water that has passed through the bypass pipe 9. it can. If the water temperature of the hot water supply port 8 is too low, the heat storage tank 3
Is further heated by the heat source device 18.

FIG. 6 is a conceptual diagram showing one embodiment of the heat storage device of the present invention. In FIG. 6, a heat storage device 25 has a heat storage tank 26 that stores heat storage material and performs heat exchange via a heat transfer wall. The heat storage device 26 is connected to a heat source device 27. The material and structure of the heat source device 27 can be appropriately selected according to the heat source to be used. For example, when utilizing the heat energy of a combustion furnace such as a garbage incinerator, a metal It is possible to take in heat energy by installing a tubular body (not shown) made of steel and passing a heat medium through the tubular body. The heat tank 26 and the heat source device 27 are
A loop is formed through 9, 30 and the pump 31, and by driving the pump 31, heat energy taken in by the heat source device 27 can be stored in the heat storage tank 26.

The heat storage device 25 has a heat exchanger 32, and is configured to heat the heated object (= water) introduced from the heated object (= water) flow path 33 by heat exchange. . The heat exchanger 32 and the heat storage tank 26 include a valve body 29, a three-way valve 3
4. The pump 35 is configured to form a loop via the valve body 30. By driving the pump 35, the heat medium heated in the heat storage tank 26 is supplied to the heat exchanger 32 to be heated. Is to be heated. The three-way valve 34
A valve for adjusting the mixing ratio of the heating medium sent from the heat storage tank 26 and the heating medium returned from the heat exchanger 32 through the bypass pipe 36, and is used for adjusting the heating temperature of the heat exchanger 32. In addition, the heat storage device of the present invention exemplified by these includes a pressure gauge, a flow meter, an overheating prevention device, a leakage prevention device, a temperature sensor, a temperature control device, a heat insulating material, an auxiliary pump,
A pressure reducing valve, a heat pump, or an expansion tank for absorbing expansion or contraction of the heat medium due to temperature change can be used as necessary.

When heat is stored using the heat storage device of the present invention, the three-way valve 34 is closed, the valves 28, 29, 30 are opened and the pump 31 is driven. Then, the heat enters the heat storage tank 26 via the valve bodies 28 and 29 and transmits heat energy to the heat storage material via the heat transfer wall.
The heat medium heated by the heat source device 27 is heated to a temperature higher than the melting point of the heat storage material by 1 ° C. or more, preferably 5 ° C. or more. The heat storage material given heat energy by the heat medium stores heat as latent heat of fusion and sensible heat due to a phase transition from a solid state to a liquid state. The heat medium that has been cooled by heating the heat storage material is heated again by the heat source device 27 via the valve 30 and the pump 31. When using the heat energy stored in the heat storage tank 26, the valve body 28 is closed,
The pump 35 is driven by opening the flow path between the valve element 29 and the valve element 29 of the three-way valve 34 and the pump 35 and the valve element 30. The heat medium is cooled to a range of (Tm-1) to (Tm-200) ° C. by the heat exchanger 32 and is sent to the heat storage tank 26, where the heat storage material nucleates on the surface of the heat transfer wall to release the latent heat. To start. Thermal storage tank 26
The heat medium heated by the heat storage material is supplied to the heat exchanger 32 via the valve body 29, the three-way valve 34, and the pump 35, and heats the heating target supplied from the heating target flow path 33. I do. On the other hand, the heat storage material that has released the latent heat transforms to a solid phase.

The heat medium that has heated the object to be heated enters the heat storage tank 26 via the valve 30 and is heated again. Heat exchanger 32
The heating temperature of the heat storage tank 26 is controlled by adjusting the three-way valve 34.
It can be adjusted by adjusting the mixing ratio of the heat medium heated by the heating medium and the heat medium circulating through the heat exchanger 32 via the bypass pipe 36. When releasing heat energy from the heat source device 27 when heating the object to be heated, the heat medium from the heat source device 27 is opened as it is, or the heat medium is mixed with the medium heated in the heat storage tank 26 to open the heat source. It can also be sent to the exchanger 32. The type of the heat storage tank 3 is not particularly limited, but a fin tube type or a fin plate type is suitable. As shown in FIG. 3, the fin tube type heat storage tank 3a used for the heat storage devices 1 and 25 has a tank body 13, and the tank 13 has a main pipe 11a extending from a heat medium outlet 14a. Is connected to many branch pipes 11b, and the other end of the branch pipe 11b is
It is connected to the main pipe 11c on the other outlet side, and is configured to be fed from the other heat medium outlet 14b to another mechanism. A large number of rectangular heat transfer fins 50 made of aluminum are connected to the branch pipe 11b at regular intervals in the pipe length direction by forming a surface perpendicular to the pipe length direction by a press-fitting method.

Here, the main pipes 11a and 11c and the branch pipe 11b are pipes 11, and together with the heat transfer fins 50, correspond to a heat transfer wall. The heat source device 10 is arranged at a position where the heat source device 10 can sufficiently contact the heat storage material in the heat storage tank 3. The temperature sensor 15 for detecting the surface temperature is installed above the outer wall of the tank 13. The main tubes 11a and 11c, the branch tubes 11b, the heat transfer fins 50, and the heat storage chamber 16 outside the heat source device 10 are filled with a heat storage material. The fin tube type heat storage tank 3b used for the heat storage devices 1, 17 and 25 has a tank body 13 as shown in FIG.
The pipe 11d extends from the inside of the tank body 13 without branching and with a certain pitch and arrangement, and is configured to be fed from the other outlet 14b to another mechanism. . Incidentally, a large number of rectangular heat transfer fins 50 made of aluminum are connected to the pipe 11d at regular intervals in the pipe length direction by forming a surface perpendicular to the pipe length direction by a press-fitting method.

Here, the pipe 11d and the heat transfer fins 50 correspond to heat transfer walls. The heat source device 10 is disposed at a position where the heat source device 10 can sufficiently contact the heat storage material in the heat storage tank 3 and has a temperature sensor for detecting a surface temperature. Pipe 11
d, heat transfer fins 50, heat source device 10, and temperature sensor 1
The heat storage material 16 is filled in the heat storage chamber 16 outside the heat storage chamber 5. Fin plate type heat storage tank 3 used for heat storage devices 1 and 25
As shown in FIG. 5, c has a tank body 13, and a main pipe 11a extends from the heat medium outlet 14a to the tank body 13, and the main pipe 11a has upper ends of a large number of plate-shaped heat medium passages 51a. The lower end of the plate-shaped heat medium flow path 51a is connected to the main pipe 11b communicating with the lower end of the plate-shaped heat medium flow path 51b, and the upper end of the plate-shaped heat medium flow path 51b is connected to the other outlet 14b. , And is configured to be fed from the outlet 14b to another mechanism. The plate-shaped heat medium flow passages 51a and 51b are provided with rectangular heat transfer fins 50 by integral press molding, integral extrusion molding, welding, or soldering. Many are connected at regular intervals or discontinuously.

Here, the main pipes 11a, 11b, 11
c, and the plate-shaped heat medium passages 51a and 51b are the pipes 11 and correspond to the heat transfer walls together with the heat transfer fins 50. The heat source device 10 is arranged at a position where the heat source device 10 can sufficiently contact the heat storage material in the heat storage tank 3. The temperature sensor 15 for detecting the temperature of the heat storage material is installed so as to be inserted in the upper layer of the heat storage material. Main pipes 11a, 11b, 11c, plate-shaped heat medium passages 51a, 51b, heat transfer fins 50 and heat source device 1
A heat storage material is filled in the heat storage chamber 16 outside the zero. Also,
In the heat storage tank, it is also an important technique to provide a depressurized or pressurized space in the heat storage tank in order to absorb a volume change due to a phase transition of the heat storage material.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. It should be noted that Examples 1 and 2
The temperature in Comparative Example 1 refers to a temperature measured by a T-type sheath thermocouple (φ1: JIS 0.75 grade; manufactured by Chuo Rika Co., Ltd.).

Example 1 Inner dimensions 350 mm (W) × 300 mm (H) × 270 mm
In (D), a sheath heater (2
kW) was installed at the bottom of the inside of the tank, and a T-type sheath thermocouple (1 mmφ) was fixed to the heater surface so as to be in contact with a SUS304 wire (1 mmφ). Further, a fin tube type heat transfer wall unit without branch shown in FIG. 7 (made by press-fitting aluminum fins into a phosphor deoxidized copper tube; fin thickness 0.3 mm, fin pitch 5.0 mm,
Tube outer diameter 12.7mm, wall thickness 1.0mm, tube length 11.1
m, tube pitch 25 mm, lattice arrangement) were installed in the center of the tank body. Here, meso-erythritol [produced by Mitsubishi Chemical Foods Co., Ltd., d _S = 1435 kg / m ³ (2
0 ° C.), d _L = 1280 kg / m ³ (130 ° C.), (d _L /
It was filled with d _S) = 0.89] 24.1kg. A total of eight T-type sheath thermocouples (1 mmφ) for detecting the temperature of the heat storage material were horizontally inserted at a height of 40, 90, 140, and 190 mm from the bottom of the tank. In addition, a heat insulating tank made of glass wool was covered with a thickness of 50 mm to form a heat storage tank.

In the heat storage process, the heater controller heats the heater surface temperature at a constant control of 160 ° C.
When the temperature of the heat storage material reached 140 ° C. on average, the heat storage was completed. In the heat radiation process, 21 ± 1 ℃
The well water was supplied from the 50 L water supply tank to the heat medium inlet of the heat storage tank at a flow rate of 10 L / min by a water supply pump using a water supply pump, and hot water was supplied from the heat medium outlet. In addition, a constant flow valve for 10 L / min (manufactured by Nippon Flow Cell Co., Ltd.,
Fan-Setter, HCT-15A) and an integrated electromagnetic flowmeter (AE115SG-AK1-LSJD1DH, manufactured by Yokogawa Electric Corporation) for flow measurement.
Was used. At this time, the water temperature at the heat medium outlet is 50
Table 1 shows the results of the integrated heat exchanged until the temperature drops to ℃.
It was shown to. Table 1 shows changes in the appearance of the tube surface after the hot water supply experiment was repeated eight times.

Example 2 A fin tube type heat transfer wall unit shown in FIG. 8 (made of aluminum fins into a phosphor deoxidized copper tube by press-fitting method; fin thickness 0.3 mm, fin pitch 2.5 mm, tube outer diameter 12 The experiment was carried out under the same conditions as in Example 1 except that 0.7 mm, a wall thickness of 1.0 mm, a tube length of 11.1 m, a tube pitch of 25 mm, and a lattice arrangement were used. The results at this time are shown in Table 1. Table 1 shows changes in the appearance of the tube surface after the hot water supply experiment was repeated eight times.

Comparative Example 1 A tube-type heat transfer wall unit (tube outer diameter 1) shown in FIG.
An experiment was performed under the same conditions as in Example 1 except that 2.7 mm, a wall thickness of 1.0 mm, a pipe length of 11.1 m, a pipe pitch of 25 mm, and a lattice arrangement were used. The results at this time are shown in Table 1. Table 1 shows changes in the appearance of the tube surface after the hot water supply experiment was repeated eight times.

[0047]

[Table 1]

[0048]

According to the present invention, a heat storage tank having excellent heat exchange performance and a heat storage device using the same can be obtained. The heat storage device of the present invention is lighter and more space-saving than a conventional heat storage device, and can prevent a phenomenon in which a heat transfer wall is corroded by a heat storage material, and has a stable heat capacity.
Not only can it be used as a hot water supply device or cooling device for other buildings or areas, but also for heat storage of unused waste heat in plants such as garbage incinerators, heat storage units for cogeneration systems for gas cooling and heating, and gas hot water. Can be used.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing one embodiment of a heat storage device of the present invention.

FIG. 2 is a conceptual diagram showing one embodiment of a heat storage device of the present invention.

FIG. 3 is a longitudinal sectional view showing one embodiment of a fin tube type heat storage tank of the present invention.

FIG. 4 is a longitudinal sectional view showing one embodiment of a fin tube type heat storage tank of the present invention.

FIG. 5 is a longitudinal sectional view showing one embodiment of a fin plate type heat storage tank of the present invention.

FIG. 6 is a conceptual diagram showing one embodiment of a heat storage device of the present invention.

FIG. 7 is an external view of a heat transfer wall unit used in the first embodiment.

FIG. 8 is an external view of a heat transfer wall unit used in the second embodiment.

FIG. 9 is an external view of a heat transfer wall unit used in Comparative Example 1.

[Description of Signs] 1, 17, 25: Heat storage device 2: Water supply device 3, 26: Heat storage tank 4, 22, 31, 35: Pump 5, 34: Three-way valve 6: Check valve 7, 19, 21, 23 , 28, 29, 30: Valve body 8: Hot water supply port 9, 36: Bypass pipe 10, 18, 27: Heat source device 11: Pipe 12: Pressure regulating valve 13, 37: Tank body 14, 38: Heat medium outlet 15 : Temperature sensors 16 and 42: Heat storage chamber 20: Branch section 24: Buffer tank 32: Heat exchanger 33: Heated body flow path 39, 41: Main pipe 40: Branch pipe 50: Heat transfer fin 51: Plate type heat medium flow path

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Hiroyuki Kakiuchi 3-1-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture Inside Tsukuba Research Laboratory, Mitsubishi Chemical Corporation (72) Inventor Masanori Yamazaki 8-Chome, Ami-cho, Inashiki-gun, Ibaraki Prefecture No.3-1 Inside the Tsukuba Research Laboratory, Mitsubishi Chemical Corporation

Claims (7)

[Claims] 1. A heat storage tank of a type in which a latent heat storage material is stored and heat exchange between the latent heat storage material and a heat medium is performed via a heat transfer wall, wherein the specific gravity of the latent heat storage material in a solid state ( d _S) ratio of the specific gravity (d _L) in liquid state for (d _L / d _S) is possible to use those in the range of 0.5 to 1.0, the heat transfer wall in contact with the latent heat storage material The heat storage tank having a fin structure on the side of the fin structure, and the fin structure portion and the heat transfer surface other than the fin structure portion are both made of metal, and the ionization tendency (I ₁ ) of the fin structure portion is determined by the fin structure. Ionization tendency of heat transfer surfaces other than structural parts (I ₂ )
A heat storage tank characterized by being larger. 2. The fin has an average thickness of 0.01 to 0.5 mm.
The heat storage tank according to claim 1, wherein 3. The heat storage tank according to claim 1, wherein the latent heat storage material comprises a sugar alcohol. 4. The heat storage tank according to any one of claims 1 to 3, (2) a heat source unit for heating the heat storage material, and (3) detecting the temperature of the heat storage material to end the heat storage or stop the heat storage. A hot water supply device comprising: a control unit for starting the heating unit; and (4) a driving unit for forcibly flowing the heat medium through the heat medium passage. 5. The heat storage temperature is set to be one point lower than the melting point (Tm) of the heat storage material.
The hot water supply apparatus according to claim 4, wherein the temperature is high in the range of 100C to 100C, and the temperature of the heat storage tank inlet of the heat medium in the heat radiation operation is lower than Tm in the range of 1C to 200C. 6. The heat storage tank according to claim 1, wherein:
(2) a heat source unit for cooling the heat storage material, (3) a control unit for detecting the temperature of the heat storage material and terminating the heat storage, and (4) forcibly flowing the heat medium through the heat medium passage. Cooling device provided with a driving unit for the air conditioner. 7. The heat storage temperature is one point lower than the melting point (Tm) of the heat storage material.
7. The cooling device according to claim 6, wherein the temperature is low in the range of -200 [deg.] C., and the temperature of the heat storage tank inlet of the heat medium in the heat radiation operation is higher than Tm in the range of 1-100 [deg.] C.