JPH037875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat storage device using rod-shaped high-density polyethylene with a stabilized shape.

From the perspective of energy conservation, storage of thermal energy has become an important issue. By the way, among the various heat storage methods, those using latent heat storage have a high heat storage density and have the feature of being able to extract thermal energy at a constant temperature, but it is necessary to use some kind of fluid as a heat medium to exchange heat with the heat storage material. Because of this, the quality of heat exchange has a great effect on the performance of the heat storage device.
(See Vol. 23, No. 213, pages 61 to 67).

High-density polyethylene has a large latent heat of fusion and good thermal stability, making it an excellent latent heat storage material. It can be modified into a shape-stabilized product that does not fluidize or cause mutual fusion even when
(See Publication No. 76078). It is also possible to coat the surface of ordinary high-density polyethylene with the high-density polyethylene that has been stabilized in this way. By using shape-stable high-density polyethylene or high-density polyethylene whose surface is shape-stabilized, it is possible to bring the heat medium into direct contact with the heat storage material, reducing heat transfer resistance and increasing heat transfer area. As a result, heat exchange is dramatically improved, and the performance of the heat storage device can be significantly improved. As described later, the present invention uses high-density polyethylene as shape-stable high-density polyethylene in a heat storage body as described above.

On the other hand, in conventional latent heat storage devices, the container is filled with a heat storage material and heat is exchanged with the heat medium through the container wall, which results in poor heat exchange performance and requires a significant increase in cost to improve heat exchange. It is said that

The above-mentioned shape-stable high-density polyethylene is
Proposals for heat storage devices in various shapes have already been made (see Japanese Patent Application Laid-Open No. 149877/1983), and experiments have also been conducted on heat storage devices using pellet-like polyethylene (ORNL/Sub-7641/ 1:
Oakridge National Laboratory (Oakridge National Laboratory, published May 1980 (see US government report)) In particular, by using rod-shaped heat storage devices, it is easier to analyze the heat storage device, and the volumetric filling rate (i.e. heat storage density) can be easily changed. Furthermore, by flowing the heat medium in the longitudinal direction, pressure loss can be reduced and a uniform flow of fluid can be obtained, among other advantages. However, even if shape stabilization is applied, there will be no fluidization or mutual fusion during melting, but the material will soften, and the volume change will be large when melted. This is considered to be the biggest problem in the practical application of heat storage devices.

This invention was made to solve the above-mentioned problems, and heat exchange is performed by forming an aggregate using rod-shaped shape-stable high-density polyethylene and flowing a heat medium in the longitudinal direction of the aggregate. The present invention provides a heat storage device in which the heat storage is performed. Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIGS. 1A and 1B are a perspective view of a main part and a plan view thereof, showing an embodiment of a heat storage body used in a heat storage device of the present invention. In this embodiment, a rod 1 made of shape-stable high-density polyethylene is partially inserted into each partition 3 having a honeycomb core-shaped cross section and made of a holding material 2.
Alternatively, the heat storage body 10 is inserted and held throughout the entire body.
That is. The height of the holding material 2 in Fig. 1 is
For example, about 5 to 2000 mm is used. In addition, since the shape-stable high-density polyethylene in the molten state is softened, the rods 1 in each partition 3 of the holding material 2 have a diameter of 1 to 20 mm as shown in Figure 2 a and b for reinforcement. The retention of the heat storage body 10 can be further improved by inserting in the longitudinal direction one or more rigid reinforcing members 4 such as metal hollow rods, solid metal rods, or arbitrary shapes having the same cross-sectional area. It can be done effectively.

Furthermore, for the same purpose, it is also effective to use shape-stable high-density polyethylene using a metal wire or a wire rod with equivalent rigidity as the core material 5, as shown in Figure 3 a and b. It is. Fig. 3 shows an example in which a plurality of rods 1' made of reinforced shape-stable high-density polyethylene with a metal wire core material 5 inserted in the longitudinal direction are held in a bundle. If the rod 1' made of density polyethylene is used, the holding material 2 is unnecessary.

Example 2 The shape-stable high-density polyethylene rod 1 was
As shown in the figure, the holding material 2 is fastened and held like a blind with a metal wire or thread 6 made of a thin material, and this is rolled up to form a heat storage aggregate to form a heat storage body 10. In this case, it may be fastened in one layer as shown in FIG. 4, or may be fastened in multiple layers. Although it may be practical to fasten only one longitudinal end, more effective retention can be achieved by fastening at both ends or at several locations as shown in FIG. If part or all of the rod 1 is made of the reinforced shape-stable high-density polyethylene rod 1' described in Example 1, the holding effect will be further improved.

Example 3 Heat storage body 10 shown in Example 1 or 2 described above
When filling a container with heat storage material 10, it may be possible to completely prevent movement of the heat storage body 10 within the container by simply providing a partition plate within the container, but it can be done even more steadily by adopting the fixing means shown below. Filling becomes possible.

One or both ends of a part or all of the heat storage body 10 are fixed to a fixing member 11 inside the container as shown in FIG. In this case, care must be taken not to block the fluid flow path at the fixed location. In FIG. 5, both ends are fixed, but a plurality of heat storage bodies 10 may be stacked and both upper and lower ends fixed.

As a fixing means, metal is attached to the surface of the rod 1 and attached to the fixing material 11 using an adhesive, or it is attached to the fixing material 11 having magnetism. The fixing material 11 may have any shape, such as a net shape or a porous material, as long as a flow path can be secured even when the heat storage body 10 is fixed.

In the case of the above fixing means, it is particularly easy to use metal adhesion, but materials other than metal may be used as long as they can be used for the above purpose. In addition, other materials that can be used for the above purpose may be connected to the ends of the rod 1, rather than being attached to the surface.

As another fixing means, it is also effective to provide a hole in the fixing member 11 to prevent the rod 1 from coming out and insert the end of the rod 1 into this hole. Or rod 1
Alternatively, a hole may be made at the end and a thin thread-like material may be passed through the hole and fixed. Further, if the rod 1' made of reinforced shape-stable high-density polyethylene described in Examples 1 and 2 is used, fixing becomes extremely easy by using the reinforcing material 4.

Figure 6 shows a rod 1 having a hook-shaped support rod 7 at its end.
A heat storage body 10 consisting of an aggregate of
It is fixed at 1'.

If the heat storage body 10 is fixed to the fixing member 11' inside the container using the above-described fixing means, the rod 1 will not be deformed even under the flow of the heat medium and can be reliably supported inside the container.

Example 4 The heat storage body 10 fixed by the means of Examples 1 to 3 described above was filled into a container so that the rod 1 was oriented vertically, and the heat storage body 10 was fixed by the means of Examples 1 to 3 described above. Heat exchange is performed by flowing a heat medium. The heat storage body 10 can be filled into a container by arranging the rods 1 horizontally in one or more rows or stacking them vertically in one or more stages. In order to prevent natural flow within the container, the flow direction of the heat medium is made to flow in from above and flow out from below during heat storage. Conversely, during heat dissipation, the heat medium is caused to flow in from below and flow out from above.

FIG. 7 is a longitudinal sectional view showing an embodiment of the heat storage device according to the present invention. In this example, the diameter is 2.6 mm,
Shape-stable high-density polyethylene rods 1 with a length of 40 cm are bundled in a cylinder with a diameter of 16 cm at a volumetric filling rate of 60%.
The heat storage bodies 10 each having a width of 5 cm at the upper and lower sides and held by retaining materials 2 made of aluminum honeycomb cores with a cell size of 3/4 inch (19.05 mm) are stacked in two layers, and both ends of the stack are placed inside the container 12. The structure is such that it is supported by a net-like fixing material 11. Note that 13 and 14 are inlet and outlet ports for the heat medium.

FIG. 8 shows that after initially maintaining the inside of the container 12 at 140°C using high-temperature ethylene glycol as a heat medium, 103°C ethylene glycol is added from the bottom by 0.5°C.
The temperature of the heat medium at the entrance and exit of the container 12 when flowing at a flow rate of /min is shown. In this figure, the curve shows the inlet temperature of the heat medium, and the curve also shows the outlet temperature, with time on the horizontal axis and temperature on the vertical axis.

Thus, the solidification temperature of polyethylene (approximately 127
℃), the fact that a constant temperature output is obtained proves that sufficient heat exchange is taking place.

Embodiment 5 FIGS. 9a and 9b are a side sectional view and a sectional view taken along the line A-A, showing another embodiment of the heat storage device according to the present invention.

In this embodiment, horizontal partition plates 15 are arranged alternately in the container 12 to form a meandering passage, and vertical partition plates 16 are installed at both ends, and each partition plate 15,
The above-mentioned heat storage body 10 is placed in the space partitioned by 16.
It accommodates. The partition plate 16 also serves as the fixing member 11 shown in FIG. 7, and is of a net shape. Then, the heat medium flows from the inlet 13 toward the inlet 14 (or vice versa) while meandering in the direction of an arrow. That is, similar to the embodiment shown in FIG. 7, the heat medium is allowed to flow in from the upper outlet port 14 during heat storage, and conversely flows from the lower outlet port 13 during heat dissipation. Further, the overall arrangement of the heat storage bodies 10 may be such that they are stacked horizontally or vertically within one partition. Further, unlike the fourth embodiment, there may be cases where there is no need to hold and fix the rods 1 and 1' due to the presence of the partition plates 15 and 16.

The shape-stable high-density polyethylene rod 1 used in the heat storage device of the present invention has a diameter of 1 to 20 mm.
A round bar with a length of 10 to 2000 mm is preferable, and any solid or hollow shape having a similar cross-sectional area may be used.

In addition, the practical range for the volume filling rate of polyethylene is 40 to 75%, but since the thermal expansion of polyethylene is large and the flow resistance of the heat medium increases, it is preferable to keep the volume filling rate of about 60% at room temperature. Fill to the desired ratio.

Furthermore, there are no restrictions on the use of the heat medium as long as it is a fluid that has good coexistence with polyethylene, but preferably a fluid with low viscosity and high specific heat, such as the above-mentioned ethylene glycol.

As explained in detail above, the present invention involves bundling a plurality of rods made of shape-stable high-density polyethylene with a diameter of 1 to 20 mm using a holding material with a honeycomb core-like cross section to form a heat storage body. The longitudinal direction of the rods constituting the heat storage body is the flow direction of the heat medium, and the heat medium and the heat storage body are placed in direct contact to exchange heat, and the volume filling rate is within the range of 40 to 75%. Because it is fixed, even if a large amount of shape-stable high-density polyethylene heat storage material is used, local blockage will not occur due to multiple melting and solidification.
Compared to conventional latent heat storage devices, its engineering reliability can be significantly improved, and the effective use of thermal energy can be promoted even more strongly.

In addition, since the rods are bundled in a sash-like manner by long holding members in the form of thin threads or bands, the structure is extremely simple, and the rods have the advantage of being able to be fixed without substantially interfering with the flow of the heat medium.

[Brief explanation of the drawing]

Figures 1a and b are perspective views and plan views of essential parts showing one embodiment of the heat storage body used in this invention, and Figures 2a and b are front views showing an example of the structure of the rod in the heat storage body of this invention. Figure 3 and its top view; Figures 3a and 3b are a front view and its top view showing another example of the rod structure;
FIG. 4 is a perspective view showing another embodiment of the heat storage body of the present invention, FIG. 5 is a side view showing an embodiment of the heat storage body fixing means of the present invention, and FIG. 6 is a heat storage body fixing means of the present invention. 7 is a longitudinal sectional view showing an embodiment of the heat storage device according to the present invention, and FIG. 8 is a diagram showing the inlet temperature and outlet temperature of the heat medium in the embodiment of FIG. Diagram showing changes over time, No. 9
Figures a and b are a side sectional view and a sectional view taken along line A--A, respectively, showing another embodiment. In the figure, 1 and 1' are rods, 2 is a holding material, 3 is a partition, 4 is a reinforcing material, 5 is a core material, 6 is a thread, 7 is a support rod, 10 is a heat storage body, 11 and 11' are Fixing material, 12
1 is a container, 13 and 14 are inlet and outlet ports, and 15 and 16 are partition plates.

Claims (1)

[Claims] 1 A heat storage body is constructed by bundling a plurality of rods made of shape-stable high-density polyethylene with a diameter of 1 to 20 mm using a holding material with a honeycomb core shape, and this heat storage body is placed in a container. , the longitudinal direction of the rod constituting the heat storage body is the flow direction of the heat medium, and the volume filling rate is in the range of 40 to 75% as an arrangement in which the heat medium and the heat storage body are brought into direct contact to exchange heat. A heat storage device characterized by being housed and fixed. 2 Construct a heat storage body by bundling a plurality of rods made of shape-stable high-density polyethylene with a diameter of 1 to 20 mm in a blind shape using a long holding material, and place this heat storage body in a container to configure the heat storage body. The longitudinal direction of the rod is the flowing direction of the heat medium, and the heat medium and the heat storage body are placed in direct contact to exchange heat, and are housed and fixed at a volumetric filling rate in the range of 40 to 75%. A heat storage device.