JPS6028911Y2 - solar collector - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a condensing collector that has excellent solar ray condensing properties and is easy to manufacture.

FIG. 1 is a cross-sectional view showing an example of a conventional condensing collector. Reference numeral 1 denotes a transparent tube whose interior is kept in vacuum, and a glass tube is usually used.

2 and 3 are heat receiving tubes, and the heat receiving tubes also serve as heat medium tubes.

4 is a semi-cylindrical reflecting mirror.

A conventional reflective mirror type solar heat collector is constructed as described above, in which sunlight passes through the upper half of the transparent tube 1, part of it is directly absorbed by the heat receiving tubes 2 and 3, and the rest is reflected by the reflective mirror 4. After that, the temperature of the heat medium 5 absorbed by the heat receiving tubes 2 and 3 is increased.

Heat loss due to conduction and convection from the heated surfaces of the heat receiving tubes 2 and 3 is minimized by keeping the inside of the transparent tube 1 in a vacuum, and similarly, loss due to radiation is minimized from the heated surfaces of the heat receiving tubes 2 and 3.
This is suppressed by a selective absorption membrane treated on the surface.

However, although the solar heat collector configured as described above has the advantage that the structure of the heat receiving part is simple, a considerable portion of the sunlight reflected by the reflecting mirror 4 is transmitted through the heat receiving tube 2,
There is a drawback that the optical loss is large because the solar radiation is lost to the sky without reaching 3. Furthermore, since most of the incident sunlight is incident on the reflecting mirror, the absorption loss by the reflecting mirror is large.

This invention aims to overcome the above-mentioned drawbacks of conventional solar collectors and provide a high-performance solar collector.

FIG. 2 is a cross-sectional view of a solar collector showing an embodiment of the present invention, in which 1 is a transparent tube whose interior is kept in a vacuum state, and 6 is a heat receiving tube with an inverted triangular cross section, which is almost inscribed in the transparent tube 1. It is fixed to the transparent tube 1 by spacers (not shown) provided at both ends.

The heat receiving tube 6 is formed by folding a single flat plate at three points so that both ends match, and is extremely easy to manufacture.

7 and 8 are tubes that are folded back into a U-shape inside the tube 6 to form an upper heat spiral tube and a lower heat medium tube, and the upper heat spiral tube 7 is located at the center of the inner surface of the upper side of the heat receiving tube 6. is fixed to.

4 is a semicircular reflecting mirror attached to the lower half of the inner surface of the transparent tube 1.

The solar heat collector configured as described above receives both vertically incident solar rays and obliquely incident solar rays through the heat receiving tube 6.
The light rays 9 can be captured by either side of the heat-receiving cylinder 6, and the light rays 9 that are incident between both vertices on the upper side of the heat-receiving cylinder 6 and both ends of the reflecting mirror 4 can be made to enter both sides of the heat-receiving cylinder 6 by the reflecting mirror 4. , it becomes possible to minimize the optical loss and the absorption loss of the reflecting mirror.

Note that although the heat receiving tube 6 can be made into a cylinder, it is difficult to provide the heat medium tubes 7 and 8 inside, and this is not suitable for mass production.

If this triangular cylinder is used, as described above, it is only necessary to fold back one flat plate, and if the heating medium tube is fixed in advance when the cylinder is a flat plate, manufacturing is extremely easy.

It is also possible to make the heat-receiving tube 6 polygonal, such as a square or a pentagon, but in this case, the heat-receiving area becomes larger and at the same time the heat-radiating area becomes larger, and the outer periphery approaches the inner surface of the tube 1, so the reflection provided inside the tube 1 Mirror 4 becomes virtually useless.

In this regard, in the present invention, the reflector 4 is used to increase the rate of light condensation on the heat receiving surface without increasing the heat dissipation area so much that the heat collection efficiency is improved.

FIG. 3 shows another embodiment, in which a triangular heat receiving cylinder 10
Each side of the curve is concave inward.

In the case of FIG. 3, each side is an arc. According to such a configuration, the optical loss and the absorption loss of the reflecting mirror can be minimized as in the case of the one shown in FIG. can.

That is, the heat radiation from, for example, point A on the side comes to be incident on the own side again as shown by the arrow, thereby reducing the heat radiation coefficient.

According to the present invention, as explained above, it is possible to provide a high-performance solar collector with excellent light collecting characteristics.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional solar collector, Figures 2 and 3 are
The figure is a sectional view of a solar collector showing an embodiment of the present invention. In Figures 2 and 3, 1 is a transparent tube, 6 and 10 are heat receiving cylinders, and 7
, 8 is a heat medium pipe, and 4 is a reflecting mirror.

Claims (1)

[Scope of utility model registration request] A solar heat collector characterized in that a transparent tube whose interior is kept in a vacuum state is provided with a substantially triangular cylindrical heat receiving part with a heat medium tube fixed to the inner surface, and a reflecting mirror that reflects light rays to the heat receiving part. .