JPS6036535B2 - Solar heat collector and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat collector and a method for manufacturing the same, and in particular, in a solar heat collector of the type in which a heat collector tube is inserted into an outer glass tube, a metal solar collector is fixed to both ends of the outer circumference of the solar heat collector. This relates to the treatment of end plates.

Since this type of end plate is fixed to the heat collecting tube, it is necessary to provide a diaphragm part and a bent fixing piece to the outer tube to allow the thermal expansion and contraction of the heat collecting tube, and for this purpose, it is made of a thin metal plate. has been done.

Therefore, adhesives containing glass components such as glass frit are used to bond the glass outer tube, but it is necessary to perform appropriate treatment on the fixed pieces in order to maintain a strong bond with the fixed pieces. It was thought that an oxidized film, which is easy to see on the glass component, could be formed on the fixed piece. That is, the oxide film has an expansion coefficient similar to that of glass, which is an oxide, and makes the fixed piece porous to promote adhesion of glass.
This oxide film is formed by heating the end plate in a humidified hydrogen atmosphere, and is particularly thick in areas that are heated strongly.During this heating, the diaphragm is hammered to increase its durability against repeated loads. It has the disadvantage of reducing power.

Furthermore, when a fixed piece or a diaphragm is formed by bending or the like a metal plate on which an oxide film has been formed in advance, there is a drawback that cracks in the oxide film that occur during the forming inhibit the adhesion of the adhesive. In particular, since diaphragm molding involves repeated heat treatment and press working several times, the oxide film may change during that time and no longer function to promote adhesion. The present invention has been made in view of the above, and embodiments thereof will be described below with reference to the drawings.

1 is the longest outer tube made of glass; 2 is a heat collecting tube inserted coaxially into the outer tube 1; 3 is a heat collecting fin fixed to the outer peripheral surface of the heat collecting tube 2; 4 is the outer tube 1. An end plate 5 made of a thin metal plate is fixed to the end of the end plate 4 to close the entrances at both ends of the tube. is provided on one post 5, and the end plate 4,
This is an exhaust port for removing the air inside the outer tube 1 which is closed at 4, and is closed after exhausting.

Thus, the so-called vacuum tube type heat collector configured in this manner has the heat collecting tube 2
A heating medium is circulated inside to receive heat.

Here, the outer circumferential green that is fixed to the end plates 4, 4 and the outer tube 1 is bent into a U-shaped groove to form the fixed piece 8, and the outer circumferential green part is bent toward the center hole 6. The diaphragm 9 is formed to have flexibility, allowing thermal expansion and contraction of the heat collecting tube 2.

Then, when fixing to the outer tube 1, frit glass 10 is injected into the fixing piece 8 and pre-sintered, and then the end of the outer tube 1 is inserted into the fixing piece 8 for final lighting, and the fixing piece 8 and It is firmly fixed to the end of the outer tube 1. In addition, an oxide film is formed on the end plates 4, 4, especially in their fixing pieces 8, 8, in order to improve their compatibility with the frit glass 10, prior to fixation with the outer tube 1. We will explain how to form two.

In Fig. 2, the end plate 4 is placed in a humidified hydrogen atmosphere furnace, and only the fixed piece 8 is attached to a heating coil 1 such as a high frequency induction heating coil.
1 and 11 for local heating.

Then, the oxide film is thick at the fixed piece 8, and is formed with a thickness corresponding to the salinity gradient. In addition, since the end plate 4 is a thin metal plate, the degree of heating at the diaphragm 9 portion is very small, and the formation of a film is also slight. Next, in FIG. 3, the end plate 4 is sandwiched between a pair of upper and lower cooling devices 12, 12, except for the 8 portions of the fixed pieces, and heated in a humidified hydrogen atmosphere furnace, so that the 8 portions of the fixed pieces exposed. Forms an oxide film only on the surface. In addition, the cooling device 12
, 12 incorporates a cold water reservoir 15 having cooling water inlets and outlets 13 and 14, and relieves heating of the diaphragm 9 portion of the end plate 4 during heating. As described above, in the solar heat collector according to the present invention, an oxide film is formed on the interlayer piece of the end plate that is fixed to the glass outer tube. It is possible to make the outer tube extremely strong, maintain a sealed state inside the outer tube, and improve heat collection efficiency.

In addition, manufacturing is simple because an oxide film can be formed by simply heating the fixed pieces of the end plate locally, and the film can be formed by simply exposing only the fixed pieces in an oxidizing atmosphere and heating them, making manufacturing easy. These manufacturing methods reduce the need to heat the diaphragm of the end plate during film formation,
Durability against repeated loads can be improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of the solar heat collector according to the present invention, Figure 2
The figure is an exploded perspective view showing one manufacturing method, and FIG. 3 is a sectional view showing another manufacturing method. 4... End plate, 8... Fixed piece, 9... Diaphragm, 10... Frit glass, 1 1... Heating coil, 12... Cooling device. Figure 3 Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A glass outer tube into which a heat collecting tube is inserted, and a fixing piece fixed to the end of the outer tube with an adhesive containing a glass component.
It consists of a fixing hole fixed to the outer periphery of the heat collecting tube and a metal end plate having a diaphragm that allows thermal expansion and contraction of the heat collecting tube.
A solar heat collector characterized in that an oxide film compatible with the adhesive is formed on the fixed piece of the end plate. 2. A glass outer tube into which a heat collecting tube is inserted, and a fixing piece fixed to the end of this outer tube with an adhesive containing a glass component.
It consists of a fixing hole fixed to the outer periphery of the heat collecting tube and a metal end plate having a diaphragm that allows thermal expansion and contraction of the heat collecting tube.
In the case where an oxide film that is compatible with the adhesive is formed on the fixed piece of the end plate, the oxide film is formed by placing the end plate in an oxidizing atmosphere and locally heating the fixed piece. A method for manufacturing a solar heat collector characterized by: 3. A glass outer tube into which a heat collecting tube is inserted, and a fixing piece fixed to the end of this outer tube with an adhesive containing a glass component.
It consists of a fixing hole on the outer periphery of the heat collecting pipe and a metal end plate having a diaphragm that allows the heat collecting pipe to expand and contract due to heat.
In the case where an oxide film that is compatible with the adhesive is formed on the fixed piece of the end plate, the oxide film is formed by placing only the fixed piece of the end plate in an oxidizing atmosphere and heating it. A method for manufacturing a solar heat collector, characterized by: