JPH0412632Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a regenerative electric heater used in a space heater or the like.

Conventional Structure and Problems The conventional latent heat storage method has a structure in which a latent heat storage material is stored in a heat storage tank or a heat storage container, and a heating source such as an electric heater is embedded in the latent heat storage material. However, this method has the problem of low heat storage rate and heat storage efficiency due to poor heat conduction of the solid state latent heat storage material.

To solve this problem, heat exchangers or fins are incorporated in the latent heat storage material in multiple stages, and a heat medium such as paraffin is mixed into the latent heat storage material.
Alternatively, measures such as mixing the encapsulated latent heat storage material and the heat medium have been taken.

The method of incorporating heat exchangers or fins in multiple stages has the problem that the flexibility of the latent heat storage material itself is impaired, the latent heat storage material becomes heavier, and at the same time, the manufacturing cost becomes high.

In the method of mixing a heat medium into the latent heat storage material,
There were problems such as a decrease in heat storage/dissipation efficiency due to the mixing of the heat medium, and a change in quality of the heat medium and the latent heat storage material when heat storage/dissipation was repeated. Furthermore, although the method of encapsulating the latent heat storage material and mixing it with a heat medium does have the effect of preventing deterioration between the latent heat storage material and the heat medium, it cannot prevent the reduction in heat storage and release efficiency due to the mixing of the heat medium. Can not. On the other hand, for local heating of the human body, etc., a structure in which only the electric heater is buried in the heat insulating material is commonly used, but this conventional electric heater requires a power cord at all times, and the space of the heater The range of use was limited to the length of the power cord. In recent years, there has been a demand for a heater that continues to have a heating function for a certain period of time even after the power to the electric heater is turned off, and this requires the development of a regenerative electric heater. However, when the above-mentioned conventional latent heat storage method is adopted as a heat storage method for such a heater, there are problems such as high cost, weight, decrease in heat storage/dissipation efficiency, or flexibility depending on the purpose of use.

In any case, conventional proposals have not provided a heat storage type electric heater that is low cost, lightweight, has high heat storage efficiency, and is highly flexible.

Purpose of the invention The purpose of the invention is to provide an electric heater for use in space heaters, heat insulators, etc., using a latent heat storage method, which has high heat storage efficiency, is low cost, lightweight, and has great flexibility depending on the purpose of use. be.

Structure of the invention The basic structure of the invention consists of a container having a groove on its outer surface, an electric heater fitted into part or all of the groove, and a latent heat storage material housed in the container. The feature of this latent heat storage type electric heater is that it has a structure in which the outer surface of the container that stores the latent heat storage material has a groove, and the electric heater is fitted into the groove. The heat generated from the electric heater is smoothly transferred to the latent heat storage material.
Therefore, the heat storage heater of the present invention can have higher heat storage efficiency than a structure in which an electric heater is simply provided on the outer surface of the container.

By using an inorganic hydrated salt with a melting point in the range of 30℃ to 100℃ as the latent heat storage material, using plastic as the container material, and using a flexible heater with an electrically insulated surface as the electric heater, the heat storage efficiency is high. Therefore, it is possible to obtain a regenerative electric heater that is low cost, lightweight, and flexible.

One of the embodiments of the regenerative electric heater of the present invention has a structure in which the container and the heater are brought into close contact using resin when the electric heater is fitted into a groove on the outer surface of the container. By bringing the electric heater into close contact with the container, the heat generated from the heater can be efficiently transferred to the latent heat storage material. The resin to be used is selected from one that has good adhesion to both the container and the heater, and has sufficient heat resistance so that no problems occur even when heated by the heater.

Furthermore, it is desirable that the resin used to bring the container and heater into close contact has good thermal conductivity. The better the thermal conductivity of the resin, the more efficiently heat can be transferred from the heater to the latent heat storage material. As a resin with good thermal conductivity, a composite resin containing an inorganic compound such as alumina or a metal such as aluminum or iron is used.

Another embodiment of the regenerative electric heater of the present invention
One has a structure in which the opening of the groove into which the electric heater is fitted is sealed. This is done in order to efficiently transfer the heat generated from the electric heater to the latent heat storage material. Moreover, by sealing the opening, there is no recess on the outer surface of the container, and the heat storage type electric heater of the present invention can be used. It is possible to eliminate the discomfort when using for local heating of the human body. The sealing method is performed by using a resin or by packing with a heat-shrinkable film.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment (1) FIG. 1 shows the configuration of a regenerative electric heater according to an embodiment of the present invention, 11 is an electric heater,
It has a structure in which a copper-nickel alloy conductive wire is covered with an irradiated polyethylene tube with a diameter of 3 mm. The power consumption when this electric heater 11 is supplied with a normal 100V alternating current is 100W. 12 is a container that stores the latent heat storage material 14, and has a thickness of
Made of 0.5mm polyethylene. The outer surface of the container 12 has a semicircular groove 13 with a diameter of 3 mm, into which the electric heater 11 described above is inserted. 400 g of latent heat storage material 14 was sealed in this container 12. The latent heat storage material 14 used here is sodium acetate trihydrate containing 1% by weight of sodium pyrophosphate as a supercooling prevention material. The melting point of this latent heat storage material 14 is 58°C, and the temperature at which crystallization begins is 53°C. The latent heat of melting and solidification is 60 cal/g, and the specific heats of solid and liquid are 0.3 cal/g°C and 0.7 cal/g°C, respectively. Therefore, the outside temperature is 20℃ and the heat storage temperature is 65℃.
When set to twenty three
It's a minute.

Next, this regenerative electric heater is one of the local heaters.
It can be used as a heater for an electric foot warmer. As a result of embedding this heat storage heater in the insulation material of the foot warmer, when the normal 100V electricity is applied, the foot warmer enters the heat retention state (30W heat dissipation) and stores latent heat in about 35 minutes after the power is turned on. The temperature of the material reached the set temperature of 65°C, and even if the electricity was turned off at this point, it was able to maintain heat retention (10W heat dissipation) for about 200 minutes.

Conventional electric foot warmer (heater power is for comparison)
20W) is in a heat retention state (20W heat dissipation) when energized.
However, when the power is cut off, the heat retention function is rapidly lost. In contrast, the heat storage electric heater of this example (heater power 100W, heat storage capacity
32.5 kcal), the heat retention function can be maintained even after the power is turned off.

The heat storage type electric heater of this embodiment has high heat storage efficiency, is lightweight (500 g or less), and is low cost, so it is extremely practical.

Embodiment (2) Fig. 2 shows a regenerative electric heater according to a second embodiment of the present invention, in which reference numeral 11 is an electric heater, in which a tube of irradiated polyethylene with a diameter of 4 mm is attached to a conductive wire of copper-nickel alloy. It has a structure covered with
The power consumption of this electric heater when normal 100V AC current is applied is 100W. A container 12 houses the latent heat storage material 14, and is made of a polyethylene film having a thickness of 100 μm and having an intermediate layer of vapor-deposited aluminum. On the outer surface of this container 12, 1
The cross section shown in 3 has a square groove with a side of 4 mm,
The electric heater 11 described above is inserted into the groove 13. Put 400 ml of latent heat storage material 14 in this container.
g was enclosed. As in Example 1, the latent heat material used here is sodium acetate trihydrate containing 1 wt% of supercooling prevention material. The heat storage capacity in this case is also 32.5 kcal, including latent heat and sensible heat, as in Example 1. Since the power of this heater is 100W, it takes about 23 minutes to store that amount of heat in an adiabatic state.

This regenerator type electric heater can be used as a heater for an electric heater, which is one type of local heater. This storage type heater was buried inside Chiyotsuki's insulation material. When the heater starts to be energized, the Chiyotsuki enters the heat retention state (40W heat dissipation), and within 40 minutes from the start of energization, the temperature of the latent heat storage material reaches the set temperature of 65℃, at which point the energization is stopped. However, it was able to maintain the heat retention state (20W heat dissipation) for 100 minutes afterwards.

Conventional electric chiyotsuki (heater power is for comparison)
(30W) can maintain heat retention when the power is turned on, but it quickly loses its heat retention function when the power is stopped. On the other hand, if the heat storage type electric heater of this embodiment (heater power 100 W, heat storage capacity 32.5 kcal) is used, the heat retention function can be maintained even after the electricity supply is stopped.

The heat storage type electric heater of this embodiment has high heat storage efficiency, is relatively lightweight (500 g or less), is low in cost, and is highly practical.

Example (3) In the regenerative electric heater of Example (1), when fitting the electric heater 11 into the groove 13 of the container 12,
The electric heater was attached tightly to the groove of the container using epoxy resin. Example of this heat storage type electric heater (1)
It was also used as a heater for an electric foot warmer. When the normal 100V is applied, the foot warmer enters the heat retention state (20W heat dissipation), and the latent heat storage material 14 reaches the set temperature of 65℃ in about 30 minutes after the electricity is turned on.
Even if the electricity was turned off at that point, it was able to maintain heat retention (10W heat dissipation) for about 200 minutes. In this way, the heat storage type electric heater of this example has a shorter time to complete heat storage than Example (1),
Furthermore, uniform heat retention was achieved.

Example (4) In the regenerative heater of Example (3), a resin with good thermal conductivity consisting of an epoxy resin containing aluminum powder was used to bond the electric heater 11 and the container 12. This heat storage electric heater was used as an electric foot warmer in the same manner as in Example (3). normal
When 100V is applied, the foot warmer enters the heat retention state (15W heat dissipation), and the latent heat storage material 14 reaches the set temperature of 65°C in about 27 minutes after the electricity is turned on, and even if the electricity is stopped at that point, the foot warmer remains warm. It was able to maintain heat retention (10W heat dissipation) for 200 minutes. As described above, in the heat storage type electric heater of this example, the time required to complete heat storage was slightly shorter than in Example (3), and moreover, a uniform heat retention state was obtained.

Embodiment (5) FIG. 3 shows a regenerative electric heater according to the embodiment of FIG. 5, which has almost the same structure as the regenerative electric heater of embodiment (2) shown in FIG. However, as shown at 15 in the figure, the difference is that the opening of the groove 13 into which the electric heater is fitted is sealed using the resin used in Example (3). This heat storage type electric heater was used as a heater for electric tipping in the same manner as in Example (2). When electricity starts, the Chiyotsuki enters a heat retention state (30W heat dissipation), and the temperature of the latent heat storage material 14 reaches 65°C in about 35 minutes after electricity starts, and even if electricity is stopped at that point, it will not heat up after that. ,
It was able to maintain heat retention (20W heat dissipation) for 100 minutes. As described above, the heat storage type electric heater of this example took a shorter time to complete heat storage than Example (2), and moreover, a uniform heat retention state was obtained.

Example (6) FIG. 4 shows a regenerative electric heater according to a sixth example, in which reference numeral 11 denotes an electric heater, which was the same as in Example (2). A container 12 houses the latent heat storage material and is made of polyethylene with a thickness of 1 mm. There is a groove 13 with a semicircular tip on the outer surface of the container so that the electric heater will come into close contact with it. I'm starting to come to the club. The electric heater 11 is fixed in the groove 13 using the resin with good thermal conductivity used in Example (4). After sealing 400g of the same latent heat storage material as in Example (2) in this container, it was packed using a laminate film bag with a 10μm aluminum foil sandwiched in the middle layer, as shown in 15 in the figure. , groove 1
The opening of No. 3 was sealed.

This heat storage type electric heater was used as a heater for electric tipping in the same manner as in Example (2). When the power starts to turn on, Chiyotsuki enters the heat retention state (20W) and heats up.
The temperature of the latent heat storage material reaches 65℃ in about 30 minutes after electricity is started, and even if electricity is stopped at that point,
After that, we were able to maintain the heat retention state (20W heat dissipation) for 100 minutes. As described above, the heat storage type electric heater of this example took a shorter time to complete heat storage than Example (2), and moreover, a uniform heat retention state was obtained.

Effects of the invention The heat storage type electric heater of the present invention is a flexible linear electric heater in which a groove is provided on the outer surface of a flexible container that stores a latent heat storage material, and the surface is electrically insulated within some or all of the grooves. It has a structure in which it is fitted and fixed.

Flexible linear electric heaters can be arranged at high density on the heat storage surface side, and the contact area between the electric heaters and the latent heat storage material is large, so heat storage efficiency is high and heat can be stored in a short time (for example, within 1 hour). There is an effect. In addition, the electric heater of the present invention is
Since it is embedded in a groove on the surface of the container containing the latent heat storage material, there is no chance of the electric heater wire shorting out and causing excessive heating in some areas.

Furthermore, since the thermal storage electric heater of the present invention does not require the mixing of additives such as a heat medium, it has the effect of slowing down the heat dissipation rate. Furthermore, if the heat storage type electric heater of the present invention is configured such that the heat storage surface side and the heat radiation surface side are provided on separate surfaces, the solid state latent heat storage material with poor thermal conductivity protects the heat radiation surface surface on the heat radiation surface side. Therefore, it is possible to dissipate heat for a long time (for example, over 1 hour).
Even during heat storage, only the heat of normal use can be conducted from the heat dissipation surface side, so the heat storage type electric heater of the present invention has the advantage that it can be used in a normal state even when heat is stored.

Furthermore, depending on the material selection of the latent heat storage material of the regenerative electric heater of the present invention, it is possible to provide a highly flexible and lightweight regenerative electric heater, and the simple configuration has the effect of providing a low-cost heater. .

Furthermore, when the regenerative electric heater of the present invention is used, for example, as a heater for local heating, it has the effect of connecting the heater to a power source only when storing heat for a short time, and then allowing heat to be radiated for a long time without a cord after storing heat.

[Brief explanation of drawings]

Figure 1 a, b, Figure 2 a, b, Figure 3 a, b,
4a and 4b are a sectional view and a plan view, respectively, showing an embodiment of the regenerative electric heater of the present invention. 11... Electric heater, 12... Container, 13...
Groove, 14...Latent heat storage material.

Claims (1)

[Claims for Utility Model Registration] (1) A groove is provided on the outer surface of a flexible container that stores a latent heat storage material, and a flexible linear electric heater whose surface is electrically insulated is provided in one or all of the grooves. A regenerative electric heater that is fitted and fixed. (2) The regenerative electric heater according to claim 1 of the utility model registration claim, in which the outer surface of the container and the electric heater are brought into close contact with each other via a resin. (3) The regenerative electric heater according to claim 2 of the utility model registration claim, in which the resin is made of a resin with good thermal conductivity. (4) The regenerative electric heater according to claim 1 of the utility model registration claim, in which the opening of the groove in which the electric heater is fitted is sealed.