JPH0524436B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heat storage device, and more particularly to a heat storage device that has high temperature efficiency and forms temperature stratification, and is suitable as a means for effectively utilizing thermal energy in various industrial processes. It is something.

[Conventional technology]

Technology for storing thermal energy, such as heat storage devices, is one of the most important technologies for effectively recovering and utilizing thermal energy. In order to enable efficient heat transfer in such a heat storage device, it is necessary to increase the heat transfer efficiency between the heat storage material and the heat medium. Methods of increasing area have been adopted. That is, the heat transfer area can be increased by adding protrusions, fins, etc. to the heat transfer surface, or by using a heat storage body with a small representative size, such as a thin cylinder, a small sphere, a thin plate, etc.

On the other hand, efficient heat transfer can also be achieved by devising the flow paths for the heat medium within the heat storage device.
In other words, if the heat medium is made to flow down from the upper side of the heat storage device during heat storage, and the heat medium flows from the bottom side of the heat storage device during heat dissipation, thereby forming temperature stratification inside the heat storage device, the internal Compared to a heat storage device in which the mixture is uniformly mixed, it is possible to store and dissipate heat with extremely high temperature efficiency. Figure 5 shows an example of heat radiation characteristics showing the relationship between heat medium outlet temperature and heat radiation time in a conventional heat storage device, where C _A is the temperature stratification type characteristic curve, and C _B is the characteristic curve of the temperature stratification type. This is a characteristic curve of a uniform mixture type. In this way, a feature of the temperature stratification type is that the temperature of the emitted heat is maintained at a high level even though the total amount of heat is the same.

However, in the conventional heat storage device as described above, when attempting to increase the heat transfer area in order to improve heat transfer performance, not only does the fluidity of the heat transfer medium decrease, but also the structure and This leads to higher costs in terms of workability. However, this is no exception even in the case of a temperature stratification type heat storage device.

[Problem that the invention seeks to solve]

The present invention relates to a heat storage device in which a heat storage material is directly contained in a heat storage device, such as a capsule type heat storage device in which the heat storage material is housed in a small container, or a direct contact heat storage device in which a shape-stable high-density polyethylene is used. The purpose of this invention is to provide a more economical and more efficient heat storage device when the device is used as a temperature stratification type.

[Means for solving problems]

In order to achieve such an object, the present invention provides a plurality of heat storage objects or a plurality of heat storage bodies containing heat storage objects in a heat storage container, and stores heat through entrances and exits provided at the upper and lower parts of the heat storage container. In a heat storage device in which heat is stored and released through a heat medium by circulating a heat medium in the container, the total heat transfer area of the heat storage objects or heat storage bodies housed near the upper and lower entrances is calculated as heat storage. The heat transfer area is larger than the total heat transfer area of the heat storage objects or heat storage bodies housed in the center of the circulation path of the container, and the heat medium flows down from the upper entrance/exit during heat storage, and from the lower entrance/exit during heat dissipation. The heat storage container is characterized in that temperature stratification is formed within the heat storage container by flowing a medium into the heat storage container.

[Effect]

The heat storage device configured in this way takes advantage of the advantages and characteristics of the temperature stratification type, and in addition, only the heat storage elements housed near the inlet and outlet of the heat medium have a particularly large heat transfer area. Therefore, heat transfer performance can be intensively and efficiently enhanced without causing a decrease in flow resistance.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

Before explaining the embodiments, the focus of the present invention will be described. In the case of a temperature stratification type heat storage device, its heat transfer characteristics are This is based on the recognition that the heat transfer efficiency is influenced by the heat transfer efficiency of the heat storage bodies in the vicinity, and in order to improve the heat transfer efficiency only by the heat storage bodies near the heat medium inlet and outlet, the heat transfer area is The central part of the heat storage device is designed to improve circulation by making the heat transfer area relatively small, thereby improving overall heat transfer performance.

FIG. 1 shows an embodiment of the invention. Here, 1
is a heat storage container, and 2 and 3 are upper and lower inlets and outlets for the heat medium. Therefore, in this example, columnar heat storage bodies 4 with narrow diameters are arranged at the upper part of the heat storage unit 1, that is, near the upper entrance/exit 2, and at the lower part, that is, near the lower entrance/exit 3, and these are arranged in the middle of the heat storage body 4, That is, a columnar heat storage body 5 having a relatively large diameter is arranged in the center of the heat storage container 1 . Note that these heat storage bodies 4 and 5 are filled with a heat storage material.

In the heat storage device configured in this way, during heat storage, the heat medium flows down from the upper inlet/outlet 2 so that the heat storage bodies 4 and 5 absorb heat, and when heat is dissipated, the heat medium is caused to flow in from the lower inlet/outlet 3. This allows heat to be radiated from the heat storage bodies 4 and 5 and absorbed.

Now, an example of the heat dissipation characteristics of such a heat storage device will be explained using Fig. 2. Here, the curve C _C
is a characteristic curve when the columnar heat storage bodies loaded in heat storage container 1, that is, those corresponding to heat storage bodies 4 and 5 in Fig. 1, are all 1 inch in diameter, and curve C _D is similar. This is the characteristic curve when all of these heat storage bodies have a diameter of 1/2 inch.

Furthermore, in the heat storage device of this example as shown in _FIG . , 60% of its central part
This is a characteristic curve when the diameter of the heat storage body 5 loaded in a portion corresponding to 1 inch is 1 inch.

To compare these characteristic curves, first, the curve
Curve C _D , which is obtained by increasing the overall heat transfer area compared to C _C , transfers heat between the heat storage body and the heat medium more quickly. In other words, the latter method provides more efficient heat exchange with less temperature drop, but on the other hand, the production cost of the heat storage device is almost double, and the heat medium flowing inside the container 1 is The fluid pressure loss increases.

On the other hand, when comparing curve C _D and curve C _E , their characteristics are largely unchanged. These characteristics provide exactly the same effect not only during heat radiation but also during heat storage. As described above, in the application example of the present invention, since the flow between the heat storage units 5 is easy in the center of the container 1, the pressure loss is small, and the total number of heat storage units does not increase significantly. The increase in production cost is about 30% compared to the case of curve C _C , and moreover, highly efficient heat storage and release characteristics can be obtained.

FIG. 3 shows another embodiment of the invention. In this example,
The heat storage bodies 14 loaded in the upper and lower parts of the container 1 are spherical in shape, and the heat storage body 15, which is cylindrical and has approximately the same diameter as the sphere, is loaded in the center. Thus, the heat transfer area is maintained large by the heat storage bodies 14 provided at the upper and lower parts of the container, and its function is the same as described above.

FIG. 4A shows yet another embodiment of the invention. In this example, the heat storage bodies 24 loaded in the upper and lower parts of the container 1 and the heat storage bodies 25 loaded in the center are of the same diameter, and the lengths are different. The body 24 is provided with radial fins 24A on its inner surface as shown in FIG. 4B. Thus, by providing such fins 24A in the heat storage body 24, the heat storage body 2
This means that the heat transfer area of the heat storage material sealed in the heat storage body 24 in contact with the heat storage body 24 is increased, and the same functions and effects as described above can be obtained. However, the shape of the fins 24A is not limited to this shape, and furthermore, the shape of the heat storage body 2
Although not shown, fins may be added at a position that does not impede the flow of water outside the tube.

〔Effect of the invention〕

As described above, according to the present invention, the total heat transfer area of the heat storage objects or heat storage bodies accommodated in the vicinity of the upper and lower entrances and exits is calculated as follows: The temperature inside the heat storage container is increased by making the heat transfer area larger than the total heat transfer area of the object or heat storage body, and causing the heat medium to flow down from the upper entrance/exit when storing heat, and flowing the heat medium from the lower entrance/exit when dissipating heat. By forming a stratified layer, it is possible to provide a high-performance heat storage device that is inexpensive, has good heat medium circulation, and has high heat exchange efficiency, and can further contribute to the effective use of thermal energy. .

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an example of the configuration of the heat storage device of the present invention, and FIG. 2 shows the temperature stratification type heat storage device.
A characteristic curve diagram showing a comparison of heat dissipation characteristics between a case where a conventional heat storage body is housed and arranged and a case where a heat storage body is housed and arranged according to the example of FIG. 1 by applying the present invention;
FIG. 3 is a sectional view schematically showing the configuration of another embodiment of the present invention, FIG. 4A is a schematic sectional view of the configuration of still another embodiment of the present invention, and FIG. 4B is the entrance/exit of FIG. 4A. FIG. 5, which is a sectional view of a heat storage body disposed nearby, is a characteristic curve diagram showing a comparison of the heat dissipation characteristics of a conventional temperature stratification type heat storage device and a mixed type heat storage device. 1... Heat storage container, 2, 3... Heat medium inlet/outlet,
4, 14, 24, 5, 15, 25...heat storage body.

Claims (1)

[Claims] 1. A plurality of heat storage objects or a plurality of heat storage bodies containing the heat storage objects are provided in a heat storage container, and the heat medium in the heat storage container is circulated through entrances and exits provided at the upper and lower parts of the heat storage container. In a heat storage device in which heat storage and heat radiation are performed via the heat medium, the total heat transfer area of the heat storage object or the heat storage body accommodated near the upper and lower entrances is determined by the flow rate of the heat storage container. The heat transfer area is larger than the total heat transfer area of the heat storage object or the heat storage body housed in the center of the path, and when the heat storage is performed, the heat medium flows down from the upper entrance/exit part, and when the heat radiation is performed, the heat medium is caused to flow down from the lower part. A heat storage device characterized in that temperature stratification is formed in the heat storage container by flowing the heat medium through an entrance and exit port of the heat storage container.