JPH0237674B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a regenerative electric heater used in a heater or the like.

Conventional configurations and their problems Traditionally, electric heaters embedded in heat insulating materials have been widely used as local heaters for the human body, etc., but these conventional electric heaters require a power cord at all times. However, the spatial usage range of the heater was limited to the length of its 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. In addition, such a heat storage type electric heater is required to be lightweight, flexible, short in heat storage time (high heat storage efficiency), high in safety, and low in cost. On the other hand, the conventional latent heat storage method has a configuration in which a latent heat storage material is housed in a robust heat storage tank, and a heating source such as an electric heater is further embedded in the latent heat storage material. There were problems in weight, flexibility, cost, etc. when adopting this conventional latent heat storage method as a heat storage method for the above-mentioned heater.

OBJECT OF THE INVENTION The object of the present invention is to provide an electric heater for use in heaters, heat insulators, etc. using a latent heat storage method, which is lightweight, flexible, has high heating (heat storage) efficiency, high safety, and low cost. It is about providing.

Structure of the Invention The basic structure of the present invention is that a latent heat storage material and a planar or ribbon-shaped electric heater are built into a sealed container made of metal foil, plastic, or metal foil/plastic laminate film, and an external power source is used. This configuration includes a lead wire that can conduct electricity to the heating element of the electric heater. Furthermore, the above-mentioned planar or ribbon-shaped electric heater has a structure in which a wire-shaped or ribbon-shaped heating element coated with electrical insulation is sandwiched between metal foil or metal foil/plastic laminate film and sealed, if necessary. Electric heaters with this configuration are lightweight, flexible, have excellent chemical resistance and water resistance, are highly safe, have a relatively uniform temperature distribution when heating the heat storage material, and have high heating efficiency. It has the characteristics of high performance and low cost. Also,
The materials used for the sealed container containing the electric heater and the latent heat storage material are metal foil, plastic, or metal foil/plastic laminate film, which are lightweight, flexible, chemical resistant,
It has excellent characteristics in terms of water resistance, safety, and cost. Furthermore, although the latent heat storage material is solid below its solidification temperature, most of it is granular or acicular, and the thickness of the latent heat storage material is set to an appropriate thickness (for example, several
cm or less), the regenerative electric heater of the present invention has sufficient flexibility.

The structure of the present invention is such that the inner wall of the sealed container and the outer wall of the upper metal foil or metal foil/plastic laminate film (i.e., planar or ribbon-shaped electric heater) in which the heating element is sealed are bonded at appropriate locations. This is what I did. Due to the existence of such a bonded portion, the heat storage type electric heater of the present invention has sufficient flexibility, especially in the bonded portion, and is resistant to the gravity of the latent heat storage material in a flexible sealed container. This has the effect of preventing the resulting deviation, keeping the heating state of the latent heat storage material by the planar or ribbon electric heater more uniform, and enhancing the heating effect.

In addition, the configuration of the present invention is such that lead wires coated with electrical insulation are connected to both ends of the heating element as necessary,
The connecting portions at both ends are present in the sealed container. It is particularly effective that the connecting portion is immersed in a latent heat storage material in a sealed container. This configuration prevents uneven heating of the heating element (uneven surface temperature of the heating element), extends the life of the planar or ribbon electric heater, and improves safety. It has the following.

Further, in the structure of the present invention, the connection portion between the heating element and the lead wire is embedded and sealed between the metal foil or metal foil/plastic laminate film that seals the heating element inside. With such a configuration, not only the heating element but also the connecting portion has chemical resistance and water resistance, and has a high safety effect.

Furthermore, the structure of the present invention is such that the connecting portion and the heating element are embedded and a part of the sealed metal foil or metal foil/plastic laminate film is inserted into the sealed container at the lead-out portion of the lead wire. It is something that is brought out to the outside. With such a configuration, not only the heating element and the connecting portion between the heating element and the lead wire, but also the lead wire have chemical resistance and water resistance, and are highly effective in terms of safety.

Description of Examples Example 1 A latent heat storage electric heater as shown in FIG. 1 was prototyped. 11 is a linear heating element, which is made of a copper alloy wire coated with electrical insulation with polyethylene.
A heater wire with an outer diameter of 3 mm, a length of 200 cm, and a power consumption of 100 W was used. Lead wires 12 were connected to both ends of the linear heating element 11. The lead wire 12 was electrically insulated and covered with polyethylene, and the connecting portion 13 between the heating element 11 and the lead wire 12 was also electrically insulated and covered with polyethylene. 14 is a metal foil covering the heating element. Here, the length is 210cm, the width is 1.4cm, and the thickness is
A 30 μm stainless steel copper foil was used. Two sheets of this ribbon-shaped metal foil 14 were used, the heating element 11 was sandwiched between them, and they were bonded together with a heat-resistant adhesive and fixed as shown in FIG. Here, the connection portion 13 between the heating element 11 and the lead wire 12 exists inside the sealed metal foil 14. In this way, a ribbon-shaped electric heater consisting of the linear heating element 11, the lead wire 12, and the metal foil 14 was obtained. Next, 16 is a plastic container;
7 is a plastic stopper for sealing the container 16, and together with 16 and 17, a sealed plastic container is formed. Here, a polyethylene pipe with an inner diameter of 1.5 cm, an outer diameter of 1.6 cm, and a length of 216 cm is used as the container 16, and the stopper 17 is a cylindrical polyethylene stopper with a diameter of 1.5 cm and a thickness of 1.5 cm.
mmψ hole) was used. Inserting the above-mentioned ribbon-shaped electric heater into the plastic container 16,
After one side of the pipe 16 was sealed (thermocompression sealing, adhesive sealing, caulking), the latent heat storage material 19 was filled from the other entrance of the pipe 16, and the entrance was similarly sealed. The latent heat storage material 19 used here is
This is a sodium acetate trihydrate containing 1% by weight of the supercooling inhibitor sodium pyrophosphate decahydrate. this
450g was weighed out, melted at a temperature of 65°C, and filled into the pipe 16 by pouring. In this way, the regenerative electric heater shown in FIG. 1 was created. The melting point of this latent heat storage material 19 is 58℃, the freezing point is 53℃, the latent heat of melting/solidification is 60cal/g, and the average specific heat of the solid is
0.3 cal/g°C, specific heat in liquid is 0.7 cal/g°C. Therefore, when the outside temperature is 10℃ and the heat storage temperature level is set to 65℃, the heat storage capacity of the regenerative electric heater is the sum of the latent heat amount of 27 kcal and the sensible heat amount of 8.3 kcal.
Since it is 35.3kcal and the heater power is 100W,
It takes about 25 minutes to store that much heat in an insulated state.

Next, this regenerative electric heater can be used as a heater for an electric chiyotsuki, which is one type of local heater. As a result of burying this heat storage type heater in the heat insulation material of Chiyotsuki, when power is input, Chiyotsuki enters the heat retention state (20W heat dissipation), and the temperature of the latent heat storage material reaches 65% of the set temperature in 31 minutes after power is input. ℃, even if you cut off the power at this point, then
It was able to maintain heat retention (20W heat dissipation) for 123 minutes.

Conventional electric chiyotsuki (heater power is for comparison)
(20W) can maintain heat retention (20W heat dissipation) when the power is turned on, but it quickly loses its heat retention function when the power is turned off. In contrast, the heat storage electric heater of this example (heater power 100W, heat storage capacity
35.3kcal), the heat retention function can be connected even after the power is turned off. In other words, a power cordless system can be achieved. Moreover, this heat storage type electric heater is relatively lightweight (530g) and flexible, and the time required for heat storage is shorter than the heat radiation time (about 1/4 in the example), making the heater highly safe. , low cost, and highly practical.

Example 2 A latent heat storage electric heater as shown in FIG. 2 was prototyped. 21 is a linear heating element, which is made of a copper alloy wire coated with electrical insulation with polyethylene.
A heater wire with an outer diameter of 3 mm, a length of 200 cm, and a power consumption of 100 W was used. Lead wires 22 were connected to both ends of the linear heating element 21. The lead wire 22 was electrically insulated and covered with polyethylene, and the connecting portion 23 between the heating element 21 and the lead wire 22 was also electrically insulated and covered with polyethylene. 24 is a metal foil/plastic laminate film covering the heating element 21.
Here, 24 is polyethylene (thickness 30 μm) / Al foil (thickness 25 μm) / 52 cm long and 15 cm wide.
A three-layer metal foil/plastic laminate film made of polyethylene (thickness 200 μm) was used. However, the laminate film was provided with a convex portion 25 measuring 3 cm in length and 1.5 cm in width at the lead wire extraction portion. This laminated film 24
Using two sheets of laminate film 24 (including the convex portion 25), the heating element 21 was sandwiched between the laminate films 24 with the 30 μm thick polyethylene layer on the inside, and fixed as shown in FIG. 1 by thermocompression bonding. Here heating element 2
1 and the lead wire 22 are present inside a laminate film 24 sealed by thermocompression bonding. In this way, a planar electric heater consisting of the linear heating element 21, the lead wire 22, and the metal foil/plastic laminate film 24 was obtained. Next, 26
is made of a metal foil/plastic laminate film, and 27 is its peripheral end, which is sealed by heat sealing. 26 and 27 form a sealed container made of metal foil/plastic laminate film. Here, 26 is a polyethylene (thickness 100μm)/Al foil (thickness 25μm) with a length of 57cm and a width of 22cm.
3 consisting of polyethylene (thickness 100 μm)
A layer of metal foil and plastic laminate film was used. First, a bag is made by sealing the three peripheral edges 27 of two laminate films 26 by thermocompression bonding, and the planar electric heaters (21, 22,
24) was inserted. At this time,
The connection part 23 between the heating element 21 and the lead wire 22 is connected to the bag 2.
6, and a part of the lead wire 22 (protrusion) 25 is exposed to the outside of the bag 26. Next, the outer layer of the laminate film 24 covering the heating element 21, that is, the thickness is 200 μm.
m polyethylene layer and the inner surface layer of the sealed bag 26,
That is, a polyethylene layer having a thickness of 100 μm was bonded and fixed at appropriate locations by heat fusion as shown in FIG. These adhesive fixing points 28 are located between the linear heating elements, and are provided at three locations. The adhesive area at one location was approximately 48 cm in length and 2 cm in width. next,
The latent heat storage material 29 was filled into a bag 26 made of a laminate film through its open mouth. The latent heat storage material 29 used here is sodium acetate trihydrate containing 1% by weight of sodium pyrophosphate decahydrate as a supercooling inhibitor. 700g of this was weighed, melted at a temperature of 65°C, and poured into a bag 26. Finally, the upper open step 27 of the bag 26 was sealed by thermocompression bonding and adhesive as shown in FIG. In particular, the space between the lead wire pull-out portion 25 and the sealing bag 26 was sealed using an adhesive.

In this way, the regenerative electric heater shown in FIG. 2 was created. Note that the melting point of this latent heat storage material 29 is 58°C,
The freezing point is 53℃, the latent heat of melting and solidification is 60kcal/g, the average specific heat of solid is 0.3cal/g℃, and the specific heat of liquid is
It is 0.7 cal/g°C. Therefore, the outside temperature 10
℃, the heat storage temperature level is set to 65℃, the heat storage capacity of this regenerative electric heater is the sum of the latent heat amount of 42 kcal and the sensible heat amount of 13 kcal, and the heater power is
Since it is 100W, it takes about 40 minutes to accumulate that much heat in an adiabatic state.

Next, as in Example 1, this regenerative electric heater was used as an electric heater. As a result of burying this heat storage type heater in the insulation material of Chiyotsuki, when the power is input, Chiyotsuki will be kept warm (20W).
The temperature of the latent heat storage material reaches the set temperature of 65℃ in 48 minutes after turning on the power, and even if the power is turned off at this point, the heat retention state (20W heat radiation) will continue for 192 minutes. We were able to.

In this way, the heat storage type electric heater of this example can be made without a power cord, and is relatively lightweight (820g).
It has flexibility, high heat storage efficiency, high safety, low cost, and high practicality.

Example 3 A latent heat storage electric heater as shown in FIG. 3 was prototyped. Reference numeral 31 denotes a ribbon-shaped heating element; here, a U-shaped ribbon-shaped heater (power consumption: 50 W) with a width of 1 cm and a total length of 34 cm was used, which was made of a thin plate of nickel alloy coated with electrical insulation with polyethylene. Lead wires 32 coated with electrical insulation were connected to both ends of the ribbon-shaped heating element 31. The connection part is 33.
34 is a metal foil/plastic laminate film covering the heating element. Here, 34 is a polyethylene (thickness 50μ) with a length of 20cm and a width of 6cm.
A two-layer metal foil/plastic laminate film consisting of m/stainless steel foil (thickness 30 μm) was used. Using two sheets of this laminated film 34,
The heating element 31 was sandwiched between the laminate films 34 with the polyethylene layer facing inside, and the heat generating elements 31 were tightly attached and fixed by thermocompression bonding as shown in FIG. 3. Here, a connecting portion 33 between a heating element 31 and a lead wire 32 is shown.
is a laminated film 3 sealed by thermocompression bonding.
Exists within 4. In this way, a planar electric heater consisting of the ribbon-shaped heating element 31, the lead wire 32, and the metal foil/plastic laminate film 34 was obtained. Next, 36 is made of metal foil, and 37 is its peripheral edge, which is sealed by welding.
36 and 37 form a sealed container made of metal foil.
Here, as 36, stainless steel foil (thickness: 100 μm) with a length of 21 cm and a width of 10 cm was used. First, three peripheral edges 37 of two sheets of stainless steel foil 36 were sealed by welding to form a bag, and a planar electric heater (consisting of 31, 32, and 34) was inserted into the bag. At this time, the connection part 33 between the heating element 31 and the lead wire 32 exists inside the bag 36, and the upper end of the planar electric heater, that is, a part 35 of the lead wire extension part 35 is exposed to the outside of the bag 36. I configured it as follows. Next, the latent heat storage material 39 was filled into the bag 36 made of metal foil through its open mouth. The latent heat storage material 39 used here was the same as the material used in Examples 1 and 2, and 340 g of this was weighed, melted at a temperature of 65° C., and filled into the bag 36 by pouring. Finally, the upper open end 37 of the bag 36 was sealed with adhesive as shown in FIG. That is, the space between the drawn-out end 35 of the lead wire 32 and the sealing bag 36 was sealed using an adhesive.

In this way, the regenerative electric heater shown in Fig. 3 was created. When the outside air temperature is set to 10℃ and the heat storage temperature level is set to 65℃, the heat storage capacity of this storage type heater is the sum of latent heat of 21.6kcal and sensible heat of 6.4kcal, which is 28kcal.
Since the heater power is 50W, it takes about 40 minutes to store that amount of heat in an adiabatic state.

Next, this regenerative electric heater can be used as a heater for an electric foot warmer, which is one type of local heater. As a result of embedding this heat storage type heater in the heat insulating material of the foot warmer, when the power is turned on, the foot warmer enters the heat keeping state (6W heat radiation) and the temperature of the latent heat storage material 39 reaches 47 minutes after the power is turned on. Even if the set temperature of 65°C is reached and the power is turned off at this point, the temperature will continue to rise to 326°C.
It was possible to maintain the heat retention state (6W heat dissipation) for minutes.

Conventional electric foot warmer (heater power is for comparison)
6W) is kept warm when power is input (6W heat dissipation)
However, when the power is cut off, the heat retention function is rapidly lost. In contrast, the heat storage type electric heater of the embodiment of the present invention (heater power 50W, heat storage capacity
28 kcal), the heat retention function can be maintained even after the power is turned off. In other words, a power cordless system can be achieved. Furthermore, this heat storage type electric heater is relatively lightweight (370 g), flexible, has high heat storage efficiency, high safety, low cost, and is highly practical.

Effects of the Invention As described above, the regenerative electric heater of the present invention is capable of short-term heat storage (for example, within one hour) and long-term heat dissipation (for example, two hours or more), and is lightweight, flexible, The present invention provides a highly stable and low-cost heater, and enables cordless use when used as a heater in a local heater or the like.

[Brief explanation of drawings]

1A and 1B, 2A and 2B, and 3A and 3B are a sectional view and a plan view, respectively, showing an embodiment of the regenerative electric heater of the present invention. 11, 21... Linear heating element, 31... Ribbon-shaped heating element, 12, 22, 32... Lead wire, 13,
23, 33...Connection part between heating element and lead wire, 1
4...Metal foil covering the heating element, 24, 34...
...Metal foil/plastic laminate film covering the heating element, 16...Plastic sealed container (pipe shape), 26...Metal foil/plastic laminate film sealed container, 36...Metal foil sealed container, 19, 29, 39...Latent heat storage material.

Claims (1)

[Scope of Claims] 1. A planar or ribbon-shaped electric heater in which a linear or ribbon-shaped heating element is sandwiched between metal foil or metal foil/plastic laminate film and sealed is made of metal foil, plastic, or metal foil/plastic laminate film.
A heat storage type that is housed in a sealed container made of plastic laminate film material, a gap between the electric heater and the sealed container is filled with a latent heat storage material, and a lead wire that can be energized to the heating element by an external power source is provided. electric heater. 2. The regenerative electric heater according to claim 1, wherein the inner wall of the sealed container and the outer wall of metal foil or metal foil/plastic laminate film with a heating element sealed inside are adhered at appropriate locations. 3. A patent claim in which electrically insulated lead wires are connected to both ends of a heating element, the connecting portions of both ends are located inside a sealed container, and the lead wires are drawn out of the sealed container. A regenerative electric heater according to item 1 of the scope. 4. The regenerative electric heater according to claim 3, wherein the connection between the heating element and the lead wire is buried and sealed between metal foil or metal foil/plastic laminate film in which the heating element is sealed. 5 A part of the metal foil or metal foil/plastic laminate film in which the connection part between the heating element and the lead wire is embedded and sealed constitutes the lead wire extension part, and a part of this lead wire is inserted into the sealed container. The regenerative electric heater according to claim 4, which is drawn out to the outside.