JPS61205752A - Hot-water supply utilizing night electric power and device therefor - Google Patents

Abstract

PURPOSE:To provide the method of hot-water supply utilizing night electric power by a method wherein a heat accumulating substance is heated to a temperature higher than the melting point thereof by utilizing night electric power and, thereafter, is cooled naturally while the same substance in melting condition is solidified by providing it with local shear stress when hot-water supply is necessitated. CONSTITUTION:The heat accumulating substance 1 is heated and the melting thereof is finished by throwing the night electric power into an electric heater 4 and, when the electric source is cut, the heat of the same substance 1 is dissipated through water, reserved in a water introducing path 3, or the wall surface of a vessel 2 and the temperature of the same substance 1 is reduced. However, the same substance 1 has supercooling property, therefore, the molten condition is maintained and releasing of the latent heat thereof is not caused even when the temperature thereof is reduced to a temperature lower than room temperature. When the supply of hot-water is necessitated, the needle 12 of a trigger device 5 is pushed to provided the same substance 1 with local shear stress, then solidification is propagated from this part to the circumference thereof and releasing of the latent heat into the water in the water introducing pipeline 3 is started, whereby the solidification is progressed further and, thus, the phenomena of solidification and heat dissipation are developed. When water is flowed continuously after pulling the trigger 12 of the trigger device 5, the latent heat, held by the substance 1, may be taken out until all of the substance 1 is solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for supplying hot water using nighttime electricity.

C. Prior Art] Since the cost of electricity at night is cheaper than that during the day, various methods have been proposed in the past to utilize this electricity to store heat and use this stored heat as a source of hot water. The most common method is to run a heater using electricity at night to heat the water in an insulated container. For example, hot water of around 80°C is made late at night using an electric heater and used for hot water the next day. There are various capacities, but for general household use, it is about 3507 kg.

In this case, the hot water tank has an external volume of about IITr when insulation is added and weighs about 400 kg, so it is installed on a strong building frame.

[Problem that the invention seeks to solve]

The time when electricity rates are cheapest is usually from 1 a.m. to 6 a.m. in the morning. On the other hand, the largest use of hot water in general households is for bathtubs, which are usually used after 6pm.

Therefore, it is necessary to store heat for 12 hours or more. For this purpose, the tank must be adequately insulated. However, even with sufficient insulation treatment, it is actually impossible to completely prevent heat from escaping, and a considerable drop in temperature usually occurs. Therefore, even if cheap late-night electricity is used, the reduction in heat storage efficiency results in an additional burden, which poses an economical problem.

In addition, in conventional devices, whether the heat storage is taken out directly or indirectly, the capacity and weight per unit of hot water have to be large due to heat insulation treatment and heat storage capacity.

The present invention attempts to solve these problems.

[Means for solving problems]

As a hot water supply solution to solve the above-mentioned problems, the present invention provides a hot water storage passage in a heat storage container filled with a heat storage material so as to be able to exchange heat with the heat storage material, and raises water by heat radiation from the heat storage material. In the heating hot water supply method, a heat storage material having a supercooling property having a melting point in the heating process of at least 50°C or higher and a freezing point in the cooling process of at least room temperature or lower is used as the heat storage substance, and this heat storage material is heated to above its melting point by an electric heater using nighttime power, then left to cool to room temperature in a molten state, and when hot water needs to be supplied, localized shear stress is applied to this molten heat storage material to solidify it. This provides a hot water supply method that uses electricity at night. And, as a suitable device for carrying out this method,
A hot water supply device in which a water conduit made of a thermally conductive material is arranged in a container sealed with a heat storage material so as to be in contact with the heat storage material, an electric heater for melting the heat storage material in the container; The present invention provides a hot water supply device including a trigger device for applying shear stress to a molten heat storage material.

In the method of the present invention, a hot water storage passage is provided in a heat storage container filled with a heat storage material having supercooling properties so as to be able to exchange heat with this heat storage material, and water is heated by heat radiation from this heat storage material. Even without providing a heat insulating wall, no large amount of heat is radiated during the time when heat is being stored, and at the time of heat radiation, substantially all of the stored heat can be taken out by passing water through the hot water storage passage.

Examples of heat storage substances with supercooling properties used in the present invention include calcium chloride hexahydrate, mirabilite monohydrate, sodium acetate trihydrate, etc. Particularly preferred are those dispersed in . For example, a substance made by dispersing or suspending sodium acetate trihydrate in 1 to 5% by weight of xanthan gum has a melting point in the range of about 50 to 65°C (the blending ratio of xanthan gum and sodium acetate trihydrate) (The melting point is approximately within this temperature range, although there may be slight variations depending on the characteristics of the gum actually used.) However, if this substance is allowed to cool without stimulation from a molten state above the melting point, it will be below 15 degrees Celsius. ,
Furthermore, it maintains its molten state even when cooled to 10° C. or lower. In this supercooled molten state, it has the property of starting to solidify when a stimulus (shock) is applied. This stimulation is preferably performed by applying localized shear stress using a needle or the like. Once the transformation from the supercooled molten state to the solidified state begins in a local area, the transformation propagates to the surrounding area due to the propagation of the solidification heat. The latent heat of this substance is 10 per lcc
It has about 0 calories, and when it is solidified by stimulation from this supercooled state, it releases about 100 calories of heat per 1 - of heat storage material. Therefore, for example, the filling volume of this heat storage material is 150 m! Even if it is only about 15,000
It can store about 13,500 kilocalories of heat, which is enough to be used as a heat source for a typical household bathtub.

In the present invention, the heat storage material is heated (melted) by electric heating using late-night electricity. This is done by incorporating an electric heater inside or outside the heat storage material container, installing a temperature detector to detect the temperature of the heat storage material at the point farthest from the point of heat transfer to the heat storage material by this heater, and detecting this temperature. The electric heater may be controlled to start and stop in accordance with the signal from the detector, or may be controlled to start and stop using a timer. It is more convenient to use a planar heating element as the electric heater and install it in the container so as to embed it in the heat storage material.

After the heat storage material having the above-mentioned supercooling property has been melted by this late-night electric power, heating by the heater is stopped and the material is left alone. By this standing, the heat storage material can maintain its molten state even if it is cooled to room temperature. As long as no stimulus is applied, this molten state will continue to be maintained, so almost all of the heating heat by the electric heater is used as latent heat until hot water is required (the sensible heat between the temperature differences in the molten state is released). can store heat in the form of

When hot water is supplied, the molten supercooled state can be solidified to release its latent heat, but this can be done by locally stimulating the heat storage material in the supercooled state by stimulating it with a needle, etc., as described above. This can be easily done by applying shear stress. In this case, it is convenient to insert a needle-shaped body into the layer of the heat storage material in advance, and apply shear stress by press-fitting the needle-shaped body from outside the container.

In carrying out the present invention, the inside of the heat storage container is divided into several units to form a plurality of independent closed spaces, each closed space is filled with a heat storage material having supercooling properties, and each heat storage material is If a stimulation means is provided independently,
The solidification from the supercooled state can be performed independently, which is convenient because the amount of heat radiation and the heat radiation time can be adjusted.

1 and 2 show examples of water heaters suitable for carrying out the method of the present invention. In the illustrated device, a water conduit 3 made of a thermally conductive material is disposed in a container 2 in which the heat storage material 1 is sealed, and a water conduit 3 made of a thermally conductive material is arranged so as to be in contact with the heat storage material 1. Electric heater 4 for melting
and a trigger device W5 for applying shear stress to the melted heat storage material l.

The container 2 is a container for enclosing the heat storage material 1, and has a closed space in which the heat storage material 1 is loaded while being isolated from the outside atmosphere. What is the material that makes up this container?

Insulation may be used, but it is not always necessary to completely insulate it as in the past; in some cases,
A metal plate such as stainless steel may be used, or a resin plate or the like may be used. The heat storage material 1 sealed in this container 1 is as follows.

It is sufficient to load the container 1 in such an amount that its maximum volume corresponds to the void volume in the container 1 so that the volume change during the phase change between melting and solidification can be absorbed.

The water conduit 3 is constructed using a material 1 having good thermal conductivity, such as a metal plate, preferably a stainless steel plate. This conduit 3 is preferably constructed in the form of a hollow panel so that it can have a large contact area with the heat storage material 1 and can store a certain amount of water in this conduit 3. . In the illustrated example, the water conduit 3 is made of a stainless steel plate and is formed so that the passage cross section (Fig. 2) when viewed in a cross section perpendicular to the longitudinal direction is a narrow rectangle. The continuous panel-shaped water conduit thus formed is arranged so as to meander inside the container 2. Such a thin panel-shaped water conduit 3 leads water to the container 2 6.
The water supply pipe 6 is connected to the city water pipe 8.

The outlet lower is connected to the hot water supply pipe 9.

By arranging such a panel-shaped water conduit 3 in a meandering manner inside the container 2, the water conduit 3 and the heat storage material l are stacked on top of each other in the container 2. An electric heater 4 consisting of a one-plane heating element is inserted into the thickness of the layer of the heat storage material 1 along a plane parallel to the water conduit 3, whereby the heat storage material 1. Meandering thin water conduit 32 electric heater with heating element 4. The three components are stacked on top of each other. Each electric heater 4 is connected to an external power supply lO via a timer, and when the power is turned on to this electric heater 4, the heat storage material 1 is heated planarly by this planar heat generation, and the whole is effectively heated. It will be melted into This power is turned on using night power as described above. When the melting is completed and the power is turned off, heat begins to be radiated through the stainless steel plate of the water conduit 3 to the water stored therein and through the wall of the container 2 to the surrounding air.

The temperature of the heat storage material 1 decreases, but by using the above-mentioned supercooling material, this heat radiation is limited to only sensible heat, and even if the temperature of the heat storage material 3 drops to below room temperature, it will not melt. Therefore, the latent heat is substantially not released. The release of latent heat is triggered by the trigger device 5.
Start by operating.

The trigger device 5 is equipped with a push-button needle 12, as shown in an enlarged view in FIG. That is, a needle 12 is inserted into the heat storage material 1 from the outside of the container 2, and by pushing the needle 12, local shear stress is applied to the heat storage material 1. In the illustrated example, the needle 12 is inserted through a perforation provided in the wall 13 of the container 2.

One half of the body is inserted into the heat storage material 1, and the other half is inserted into the container wall 1.
It protrudes outward from the surface of 3 while being sealed with Teflon 14. A push button 15 is attached to the head of the needle 12 that protrudes to the outside. This push button 15
The attached needle 12 is slidably and elastically attached via a spring 17 inside a guide tube 16 fixed to a container wall 13. The spring 17 imparts elasticity to the needle 12 with the push button 15 so that it extends outward in its natural state without any external force applied thereto. Follow,
Therefore, in order to press the push button 15, a force against this spring 17 must be applied. Therefore, when it is necessary to supply hot water during the day, when the push button 15, which is extended outward due to the action of the spring 17, is pushed in against the elastic force of the spring 17, the tip of the needle 12 will displace the melt that is present there. The heat storage material 1 in the state is stimulated locally, and solidification starts from this area. Once this solidification starts, this solidification reaction propagates to the surroundings, and along with this, the radiation of latent heat progresses. In the device of the present invention, since the thermally conductive stainless steel plate is in planar contact with the heat storage material 1, this heat radiation starts effectively to the water in the water conduit 3, and when this heat radiation occurs, solidification further progresses. This very favorable solidification heat dissipation phenomenon develops.

Then, after pulling the trigger for heat dissipation using the trigger device 5, water continues to flow through the water conduit 3 until substantially all of the heat storage material 1 that has been in a molten state solidifies. All of the latent heat can be extracted. This trigger device 5 can be provided at any number of locations depending on the case.

As described above, according to the two aspects of the present invention, it is possible to store heat using inexpensive nighttime electricity and take it out when hot water is needed the next day without leaking it out. In the case of the present invention, it is no longer necessary to ensure the completeness of heat insulation treatment as in the past, so the device can be made lightweight and compact, making it very suitable for general household water heating equipment. .

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a water heater suitable for carrying out the method of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a schematic sectional view showing an example of a trigger device. Figure ・There is. 1. Heat storage material, 2. Heat storage container, 3. Water conduit, 4. Electric heater of planar heating element. 5...Trigger device, 12...Handle, 15...Push button, 17...Spring.

Claims (4)

[Claims] (1) In a hot water supply method in which a hot water storage passage is provided in a heat storage container sealed with a heat storage material so as to be able to exchange heat with the heat storage material, and the temperature of water is raised by heat radiation from the heat storage material, the heat storage material is used in the heating process. Using a heat storage material with supercooling properties, the melting point of which is at least 50°C or higher, and the freezing point of which is at least room temperature or lower during the cooling process, and this heat storage material is heated to a temperature higher than the melting point by an electric heater using nighttime electricity. A hot water supply method using nighttime electric power, characterized in that the heat storage material in the molten state is then allowed to cool to room temperature in a molten state, and is solidified by applying local shear stress to the heat storage material in the molten state when hot water supply is required. (2) The method according to claim 1, wherein the heat storage material is sodium acetate trihydrate dispersed in xanthan gum. (3) A water heater in which a water conduit made of a thermally conductive material is arranged in a container sealed with a heat storage material so as to be in contact with the heat storage material, the water supply device being used for melting the heat storage material in the container. A water heater for use in the method according to claim 1, comprising an electric heater and a trigger device for applying shear stress to the molten heat storage material. (4) The device according to claim 3, wherein the heat storage material is sodium acetate trihydrate dispersed in xanthan gum.