JPS6229891Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat collector used for heat recovery such as a solar collector.

As shown in FIG. 1, a heat collector generally provided in a solar collector that collects solar heat has heat collection tubes 2 arranged along the axis of a hollow body 1 made of transparent resin glass, etc. A mirror surface 3 is formed on a part of the inner surface of the mirror. That is,
The solar heat that has entered the hollow body 1 is applied directly or reflected by a mirror surface 3 to the heat collecting tube 2, thereby heating the heat collecting medium. The mirror surface 3 is usually formed by adhering amalgam to the inner surface of the hollow body 1 by vapor deposition, etc., and the oxidation of this mirror surface 3 and the heat collecting tube 2
The internal space of the hollow body 1 is made into a vacuum in order to suppress heat loss from the hollow body 1 as much as possible.

However, in the heat collector having this structure, since the length of the hollow body 1 is relatively long, the internal space volume becomes large, which increases the cost in increasing the degree of vacuum.
If the degree of vacuum is low, the mirror surface 3 will deteriorate quickly and its life will be shortened. Furthermore, it is extremely difficult to optimize a curved surface such as making the mirror surface 3 a paraboloid, and it is difficult to improve light collection performance. Furthermore, if air leaks into the internal space during actual use, the mirror surface 3 will immediately deteriorate due to condensation or water immersion, significantly impairing the heat collection performance, and furthermore, the reliability will be low. .
In this way, there were many shortcomings.

The object of the invention is to eliminate the above-mentioned drawbacks and to provide a cheaper, more efficient and more reliable heat collector.

To this end, the present invention is characterized in that the hollow body has a double structure over at least the area where a mirror surface is to be formed, and a mirror surface is formed on the inner surface of the portion defined by the double structure. In other words, a small space is defined to form a mirror surface, thereby making it easier to improve the degree of vacuum inside the space, improving the ability to prevent mirror surface deterioration, and selecting the wall curvature to create a double structure. As a result, the heat collection performance was improved.

A preferred embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

The heat collector shown in FIG.
An inner tube 11 extending over a range of 180° is disposed, and partition walls 12 formed on both side edges of the inner tube 11 are fixed to the inner surface of the outer tube 10 to define a small arc-shaped space 13 with a small gap within both tubes. be. The mirror surface 14 is this small space 1
It is mainly formed on the outer surface of the inner tube 11 facing 3. However, the mirror surface 14 may be intentionally or incidentally formed on the surfaces of the outer tube 10 and the partition wall 12. The heat collecting tube 15 is arranged along the axis of the outer tube 10 and connected to guide a heat collecting medium such as water inside. Preferably, this surrounding space 16 is suitably evacuated to reduce heat loss. As described above, heat from the outside is directly or reflected by the mirror surface 14 and applied to the heat collecting tube 15, thereby collecting the heat. Further, the end portion of the tube is sealed in the same manner as before.

According to this configuration, the mirror surface 14 can of course be formed with amalgam by vapor deposition, plating, plating, etc., and since the small space 13 is defined, it can also be formed using a getter. . In this case, the getter can not only improve the degree of vacuum, but also form a vacuum and a mirror surface 14 simultaneously. In any case, since the space volume exposed by the mirror surface 14 is small, it is easy to improve the degree of vacuum, and by using the same material for the outer tube and the inner tube, it is possible to eliminate the effects of differences in thermal expansion with the material of the heat collecting tube. This ensures mirror protection at the end of the tube and extends its service life. Further, since the curved surface of the inner tube 11 can be selected to be a preferable curved surface in consideration of the position of the heat collecting tube 15, it is possible to improve the heat collecting ability and the heat collecting efficiency. Moreover, since the vacuum space 13 and the outer tube 10 are located outside the main mirror surface, it is possible to minimize heat loss from this area. It is of course possible to modify the partition wall 12 so that it extends smoothly as shown in FIG. 2A.

FIG. 3 shows the inner tube 11 of the embodiment shown in FIG.
It is a complete 360° tube. in this case,
By making the space 17 formed between the two tubes into a vacuum state as well as the space 13 for forming the mirror surface 14, heat loss can be kept small without making the space inside the inner tube 11 particularly vacuum. . If the space 16 is kept at normal pressure in this way, there is no need to seal the heat collecting tube and the inner tube, and the tube end can be sealed with only the inner tube and the outer tube, which improves reliability with respect to the degree of vacuum. . Furthermore, the volume of space created by vacuum is significantly reduced, resulting in an effect that can improve productivity.

It goes without saying that the heat collector of the present invention can be used not only as a solar collector but also for recovering waste heat radiated from the walls of a heating furnace or the like.
Further, the cross-sectional shape of the outer hollow body can be appropriately selected depending on the intended use.

As described above, the heat collector according to the present invention has a double structure that defines a small volume space especially over the area where the mirror surface is formed, which mainly simplifies the vacuuming process and reduces productivity and costs. enable. In addition, by using a getter, etc., it is possible to improve the degree of vacuum in the mirror-exposed space, which improves the protection of the mirror surface. Furthermore, the curvature of the mirror surface can be arbitrarily selected due to the double structure.
Heat collection performance can be improved. You can get a lot of effects such as.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional heat collector. FIG. 2 and FIG. 2A are a sectional view and a partial sectional view showing a partial modification of a heat collector according to an embodiment of the present invention. FIG. 3 is a sectional view of another embodiment of the present invention. 10... Outer tube, 11... Inner tube, 12... Partition wall,
13... Small space, 14... Mirror surface, 15... Heat collecting tube.

Claims (1)

[Claims for Utility Model Registration] (1) A heat collecting tube that guides a heat collecting medium is arranged inside a hollow body made of a material that transmits heat, and heat that has entered the hollow body from the outside is directed to the heat collecting tube. In the heat collector in which a mirror surface that reflects light is formed along the inner surface of the hollow body in a range extending approximately half of the outer circumferential direction of the hollow body, the hollow body has a double structure at least in the range forming the mirror surface, A heat collector characterized in that a mirror surface is formed on at least the surface of the inner hollow body facing the gap of the double structure. (2) The hollow body has a double pipe structure consisting of an inner hollow body and an outer hollow body, and a mirror area is defined between the two hollow bodies, and the space between the hollow bodies is evacuated, and the inside of the inner hollow body is A heat collector according to claim (1) of the utility model registration, characterized in that the pressure is set to normal pressure.