JPS608423B2 - solar collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar collector that receives sunlight and collects heat.

Conventional collectors, such as flat plate collectors, are made of metals with good thermal conductivity (Cu, AI, stainless steel, etc.) to improve heat collection efficiency, but if the metal is exposed as is, sufficient efficiency cannot be achieved. Usually, a heat collecting film is formed on the surface.

For example, when copper is used, black oxidized steel (Cu○, C
However, the coating processing equipment is very large-scale and requires a huge amount of capital investment, which increases the cost and makes the product price extremely high. It has become. Therefore, aiming at lower costs,
ln203 resin diluent such as silicone polyester resin
, Sn02, and other semiconductor fine particles and pigments are mixed into a paint (black paint with selective absorption characteristics) and painted on the collector material, but when the collector material is copper or steel alloy, However, the adhesion and durability were insufficient, and it could not withstand long-term use from 10th grade to at least 2nd grade.Also, in place of the above paint, acrylic resin Attempts have been made to form a baked-on hardened film with a black color, but there was still a problem with durability.The present invention was created to eliminate these drawbacks, and is an inexpensive and durable film. The purpose of the present invention is to obtain a solar heat collector with high heat collection efficiency.

The gist of this is that the heat collecting coating is not formed directly on the steel plate, but is formed via a bad lead coating. Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a collector, in which a copper distribution pipe 3 is heat-conductively caulked to the central curved part of copper-made ripening fins. On the surface of the heat collecting fin 1, a zinc layer 7 of approximately 5 mm thick is formed by electrogalvanizing, and on the surface of the zinc layer 7, a selectively absorbing heat collecting coating 5 is baked and hardened to a thickness of 3 to 5 mm thick. is formed. The steps for forming the films 4 and 5 on the heat collecting fin 1 are as follows.

First, a raw steel plate (deoxidized steel) with the shape shown in Figure 2 A is passed through a pre-treatment line of a normal plating process to be cleaned, and then zinc is coated with electrolytic galvanized several times as shown in Figure 2. 5) and then post-processed and sealed (chromate, phosphoric acid treatment) to form a zinc coating 4.

Immediately thereafter, a selectively absorbent commercially available paint is diluted with a solvent to give an appropriate coating viscosity, which is then spray coated and allowed to dry in the morning to form a heat collecting film 5 as shown in FIG. In addition,
The thickness of the zinc coating 4 is preferably about 2 to 10 thick.

Furthermore, as the paint for forming the heat collecting film 5, a heat collecting black paint (without selective absorption) such as an acrylic resin baking paint or a polyester resin glazing paint is diluted with a solvent to an appropriate paint viscosity. be able to. As a method of painting, in addition to the above-mentioned spray painting, bond painting is used. The preferable thickness of the selectively absorbing paint is about 3 to 5 µm, but the thickness of the heat-collecting black paint is about 20 µm. Any of the above paints contains a heat collecting film 5 containing organic matter.
becomes. The present invention is extremely superior in that a heat collecting coating with excellent durability and adhesion can be formed without using expensive equipment for forming oxidized steel.

*In other words, the collector of the present invention is made using conventional plating processing,
Since the coating processing method and equipment can be used as they are, the processing is easy and the equipment is also inexpensive, resulting in a very low cost. Furthermore, the heat collecting film has good adhesion and long-term durability, and has the advantage that heat collecting efficiency does not decrease due to vertical movement.

In order to compare the durability of the coating of the collector of the present invention with conventional ones, JIS salt water lamp test, hot water immersion test (4)
0° C. for 500 hours), and the results shown in the table below were obtained. As is clear from this result, the collector coating of the present invention (
Tests b and c) in the table have extremely excellent durability performance.
oS: Solar absorption rate (wavelength 0.3 to 2 French) e: Emissivity (
(Wavelength 4.15 degrees, 100°C) ×: Rust or paint film blisters, peeling is noticeable, and durability is poor. ○: Slight rusting, paint film blisters.

As mentioned above, the collector of the present invention is inexpensive and has the extremely advantageous ability to collect heat stably over a long period of time without deteriorating the heat collection efficiency due to the heat collecting film. It has a remarkable effect.

[Brief explanation of the drawing]

Figure 1: Simplified sectional view showing the outline of the collector of the present invention, Figure 2
Figure A, Mouth: An explanatory diagram of the manufacturing process of the collector of the present invention. Symbols: 1: Heat collecting fin, 4: Zinc film, 5: Heat collecting film. Figure 1 Figure 2

Claims (1)

[Claims] 1 In a solar collector made of copper or copper alloy,
A solar heat collector characterized in that a zinc coating is provided on the surface of the collector, and a heat collecting coating containing an organic substance is formed on the zinc coating.