JPS59221595A - Heat accumulation type electric heater - Google Patents

Abstract

PURPOSE:To obtain a latent heat accumulation type electric heater used for a room heater or a heat insulator having high flexibility, high heat accumulation efficiency, light weight and reduced thickness by containing a flexible linear heater in a vessel for containing latent heat accumulation material formed of a flexible material. CONSTITUTION:Two polyethylene films are superposed, the ends of the films are thermally press-bonded to form a slender bag shape as a flexible flat vessel 2, a linear heater 1 is passed in the center of the vessel, one end 3 of the vessel 2 is thermally press-bonded to secure the heater 1. Then, a latent heat accumulation material 5 is filled from the other end 4 of the opened vessel 2. The material 5 contains aqueous salt of 3 sodium acetate which includes 1wt% of hydride salt of 10 overcool preventing agent of sodium pyrophosphate. After the material 5 is cooled and solidified, the top of the vessel 2 is thermally press-bonded and sealed to obtain an electric foot heater. It can be used as an electric vest or a cooking heat insulator by altering the shape of the vessel.

Description

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

Conventional Structure and Problems A conventional latent heat storage device 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. In such devices, heat storage rate, heat radiation rate, and heat storage efficiency are problems, and to solve these problems, metals such as Vc heat exchangers, fins, and heat media are used.

Alternatively, measures such as encapsulation of latent heat storage materials are being taken. On the other hand, as a local heater for the human body, etc., an electric heater that is buried during the heat retention period is commonly used, but this conventional electric heater requires a power cord at all times, and the spatial usage range of the heater is limited. Limited to power cord length range.

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, adopting the above-mentioned conventional A heat storage method as a heat storage method for such a heater may be problematic in terms of flexibility depending on cost, weight, and purpose of use. -O Object of the Invention The object of the present invention is to provide a latent heat storage electric heater which is highly flexible, has high heat storage efficiency, is low cost, lightweight and thin, and is used in heaters, heat insulators, etc.

Structure of the Invention The heat storage type heater of the present invention is characterized in that a flexible linear heating element is built into a container for storing a latent heat storage material made of a flexible material. By doing so, the above-mentioned problems are solved.

The container is a film bag-like body made of thermoplastic resin or metal, and has a flat structure. Furthermore, depending on the purpose of use or the thickness of the container, it is bonded and fixed at all specific locations between the opposing walls of the container. Basically, the size of the container depends on the desired heat storage (input) time, heat storage capacity, and unit length of the linear heating element used.

It is determined by the power consumption per unit time and the thermal conductivity of the latent heat storage material. Generally, the linear heating element moves within a flexible container and may be located at an skewed location. In this case, not only is it not possible to obtain a stable heat storage time, but also the effective utilization rate of the latent heat storage material is reduced. Therefore, in order for a flexible container to maintain its flat structure and completely prevent the movement of linear heating elements within the container, specific locations of the container must be fixed using simple methods such as adhesives, thermocompression bonding, or welding. Fully bonded between opposing walls.

to be fixed. The thickness and number of adhesives at a particular location is primarily determined by the container thickness, the size and length of the linear heating element, and the desired heat storage (input) time. Thereby, it is possible to bring all the latent heat storage metals into the melted state (heat storage state) within the set heat storage (input) time, and there is an advantage that the heat storage efficiency can be brought close to 100 points.

DESCRIPTION OF EXAMPLES Hereinafter, details of the present invention will be explained based on examples.

Example 1 We prototyped a latent heat storage type electric heater as shown in Figure 1.

1 is a linear heating element, which is made of a copper alloy mesh wire with an electrically insulated surface and has an outer diameter of 311 m and a length of 20 (
:Ill, on the surface of the heater wire with power consumption of 2oW,
It is coated with polyvinyl chloride to a total thickness of 0.5.

Next, a polyethylene film with a thickness of 0.3πm and a length of 2 I
CaN, width 5C)〃 film 2 gold overlapping +! :% The end of the film was heat-pressed in the length direction with a width of rsmm, and a long and narrow bag-like metal was fabricated to form a flexible flat container 2.

Then, insert the linear heating element 1fK into this: the center part,
One end 3 of the flat container 2 is thermocompressed, and a linear heating element 1f; c
Fixed. Next, the other end 4 of the open flat container 2 is completely filled with the latent heat storage material. The latent heat storage material 6 used here contains 1 portion of the supercooling inhibitor sodium birophosphate decahydrate.
It is sodium acetate trihydrate containing a weight ratio. This 1
65g was weighed out, melted at a temperature of 65°C, and then poured into the open end of the flat container 2. After waiting for the latent heat storage material 5 to cool and solidify, the upper end of the flat container 2 was sealed by full heat compression. A regenerative electric heater was manufactured through the above steps.

The melting point of this latent heat storage material is 58°C, and the freezing point is 53°C.
, the latent heat of melting and solidification is 60ω1/1, the average specific heat of solid is 0.3 cal/g℃, and the specific heat of liquid is O.7 cal/
It is y℃.

Therefore, the outside temperature is 20℃, and the total heat storage temperature level is 65℃.
When set to The time required to do this is approximately 20 minutes.

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 insulator of the foot warmer, the foot warmer enters the heat retention state (6.8W heat dissipation) when connected to the power supply, and the latent heat storage system is activated within 30 minutes after the power is turned on. The temperature reached the set temperature of 65°C. Even if the power was turned off at this point, the heat retention state (6.8 watts of heat dissipation) continued for the next 60 minutes.

Conventional electric foot warmers with a heater power of 6.8 watts naturally keep warm (5.8 watts of heat dissipation) when the electricity is on.
However, when the power is cut off, it rapidly loses its heat retention function. In contrast, the heat storage type electric heater of the present invention (heater power 2oW, heat storage capacity 5.01cal)'
By using this, the heat retention function can be maintained even after the power is turned off. Moreover, this regenerative electric heater is lightweight (100g
(below), and is thin (6 mm or less) and highly practical.

Example 2 A latent heat storage electric heater as shown in the front cross-sectional view of FIG. 2(A) and the cross-sectional view of FIG. 2(B) was manufactured as a prototype. Parts corresponding to those in Example 1 are given the same reference numerals.

1 is a heater wire (length 120cm, power consumption 30
The surface of the wafer was coated with polyvinyl chloride to a total thickness of 0.5 mm. Next, the thickness o, s made of polyethylene
M shoulder, length 22C〃l1 Width 20cm 2 films are superimposed and both left and right ends are fully heat-pressed with a width I cm, then 5
Thermocompression bonded parts θ having a width of 1 cm and a length of 16 cm were made every 2 cm. After passing the linear heating element 1 all the way through the uncrimped part of the container 2, the bottom end was thermocompression bonded with a full width of 1゛0〃, and the top end was also thermocompression bonded with a portion left, resulting in a flexible flat plate container 2. .

Next, the latent heat storage material 5 is filled into the flat container 2 from a part of the upper end where the reed is open. The latent heat storage material 5 used here is the same as that used in Example 1. The filling amount is 1Q
After filling it in a completely molten state (66° C.), the opening was sealed by thermocompression. Through the above steps, the regenerative electric heater shown in FIG. 2 was completed.

When the outside air temperature is set to 20°C and the total heat storage temperature level is set to 66°C, the heat storage capacity of this regenerative heater is the sum of the latent heat amount of 61 cal and the sensible heat amount of 1.6 ml, and the heater power is 3.
Since it is 0 watts, it takes about 18 minutes to store that amount of heat in a fully insulated state.Next, this regenerative electric heater can be used as a heater for an electric vest, which is a type of local heater. can. When this heat storage type heater is buried in the heat insulation material of a vest and the power is turned on, the vest enters the heat retention state (10 watts of heat dissipation), and the temperature of the latent heat storage material rises to 65% of the set temperature within 30 minutes after the power is turned on. ℃ reached. Even if the power was completely cut off at this point, the heat retention state (heat dissipation of 10 watts) could be maintained for the next 60 minutes.

Conventional electric vests (heater power was set at 10 watts for comparison) can maintain heat retention (10 watts of heat dissipation) when the electricity is turned on, but when the power is turned off, the insulation function quickly runs out. On the other hand, when the heat storage type electric heater of the present invention (heater power: 30 watts, heat storage capacity: 7.61 cal) is used, the heat retention function is fully maintained even after the power is turned off. In other words, the power cord can be made cordless. Moreover,
This storage type electric heater is relatively lightweight (160g or less).
It is thin (5 mm or less) and highly practical.

Example 3 All prototype latent heat storage type electric heaters as shown in Figure 3 were fabricated.

Parts corresponding to those in Embodiments 1 and 2 are all designated by the same reference numerals. The linear heating element 1 is made of a copper alloy mesh wire with an electrically insulated surface, has an outer diameter of 4 mm, a length of 120 an, and a power consumption of 5.
The surface of a 0 watt heater wire is coated with polydetrafluoroethylene to a total thickness of 0.6 mm.

Stainless steel thickness 02mm + length 20cm,
Two films with a width of 24 cyn were superimposed and both left and right ends were welded, and spot welds were made every 4 cm. After passing through the linear heating element 1fK, the lower end is completely welded to form a flexible flat container 2. Next, fill the latent heat storage material with gold from the upper end of the flat container 2, which has an open trench. The latent heat storage material 6 used here is macanenium chloride hexahydrate. 400 f of this gold was weighed, melted at a temperature of 125° C., and then poured into the flat container 2 from the upper end.

After waiting for this latent heat storage 4A to cool and solidify, the entire upper end of the flat container 2 was sealed by welding. Above process VC
Thus, the regenerative electric heater of the present invention was completed.

The melting point of this latent heat storage material is 117°C, and the latent heat of melting and solidification is 40 cal/! , average specific heat of solid 0.14c
al/f °C, the specific heat of liquid is o24cal/fc
0 outside temperature 20"C, heat storage temperature level 12"
When set at 5℃, the heat storage capacity of this regenerative heater is 211, which is the sum of the latent heat amount of 161g1 and the sensible heat amount of 6.27g, which is 22.2.
Since the heater power is 50 watts, the time required to store that amount of heat in an adiabatic state is approximately 31 minutes.

This heat storage type electric heater can be used as a cooking warmer. When a heat storage type heater is installed inside the heat insulating material of a cooking heat insulator and the power supply is fully connected, the heat insulator enters a heat retention state (20 watts of heat dissipation). The temperature reached 126 degrees Celsius, and even if the power was turned off at this point, the heat retention state (2.0 watts of heat dissipation) could be maintained for 70 minutes.

In this way, even if you disconnect the power cord, you can keep the food warm for a while while you eat in the reeds.
This prevents the food from cooling down while being transported from the cooking room.

Effects of the Invention As explained in the embodiments, the flat plate-shaped heat storage type electric heater of the present invention is an electric heater that has high heat storage efficiency, is lightweight, thin, and highly flexible. Furthermore, it is possible to temporarily make conventional heaters, heat insulators, etc. cordless.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of a regenerative electric heater according to the present invention, FIG. 2(A) is a front sectional view of another embodiment, FIG. FIG. 3 is a sectional view of still another embodiment. 1...- Linear heating element, 2... Flat container, 5... Latent heat storage material, 6... Thermocompression bonding part, 7... ...Spot welding area. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 j, -n Figure 3

Claims (3)

[Claims] (1) A regenerative electric heater comprising a container for storing a latent heat storage material with a built-in heater metal, the container being made of a flexible material, and the heater being made of a flexible linear heating element. . (2) The container is a thermoplastic resin film bag-like body or a metal film bag-like body, and the opposing film walls are fixed by adhesion at specific locations. The regenerative electric heater according to item 1. (3) The regenerative electric heater according to claim 1, wherein the flexible linear heating element is covered with a plastic having heat resistance, corrosion resistance, and electrical insulation properties.