JPS5835970Y2 - solar heat collector plate - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a solar heat collecting plate, and an object of the present invention is to prevent cracking or destruction of the welded joint portion of the heat collecting plate due to freezing of water in the water passage.

Generally, as shown in Fig. 1, a solar heat collector plate is made by locally welding two thin plates 1 and 2 made of stainless steel plates or the like to form a number of water passages 3 (this part is indicated by reference number 4). is formed by

In forming a large number of water passages, conventionally, as shown in Fig. 1, both sides of each water passage 3 are all joined by welding 4 such as seam welding. Since it is divided by other water passages adjacent to the left and right and the welded joint portion 4 of the thin plates 1 and 2, it has the following drawbacks.

In other words, if water remains in the water passage when the heat collecting plate is not used in winter, this water will freeze and its volume will increase, but since there is no escape for this increased volume, the water flow is
As shown by the broken line in the figure, it expands and deforms, and if this expansion and deformation is repeated several times, the welded joint part cracks or breaks, and as a result, the water passageway may be damaged.

Conventional solar heat collector plates have these drawbacks, so
Although instructions are given to drain the water from the water channels when not in use during the winter, in practice this is often forgotten, and as a result, solar heat collector plates are often destroyed.

The present invention was devised in view of these circumstances, and aims to provide a solar heat collector plate with excellent freeze-damage resistance.

A preferred embodiment of the present invention will be described in detail below with reference to FIG.

In Figure 2, 1 and 2 are two thin plates such as stainless steel plates, 3
are a large number of water passages formed by these two thin plates.

To be more specific, the surfaces of the two thin plates are treated with black oxidation as a selective absorption surface treatment to improve heat collection efficiency, and the numerous water passages are not completely independent water passages, but are separated from each other. The upper and lower parts communicate with each other.

Of course, this also applies to the conventional solar heat collector plate illustrated in FIG.

Now, according to the conventional structure, each of the many water passages was divided from other water passages adjacent to the left and right by welded joints of thin plates, but according to the present invention, as shown in Fig. 2, Each of the water passages 3 is separated from the other water passages adjacent to one side by a welded joint 4 between the thin plates 1 and 2, as in the past, but is separated from the other water passages adjacent to the other side by the welded joints 4 between the thin plates 1 and 2. It is delimited by a non-welded contact portion 5 of.

With this structure, even if the water in the water passage freezes and its volume increases, causing the water passage to expand and deform,
The increase is the contact area 5, which is the valley that is not welded.
is absorbed by the swelling, so that no excessive force is applied to the welded joint 4, and cracking or destruction of the welded joint 4 is prevented.

Note that when the frozen water in the water passage melts, the portion 5 returns to its original shape due to the elasticity of the thin plates 1 and 2.

The following tests were conducted to investigate the freeze-damage resistance of the solar heat collector plate according to the present invention.

The conventional solar heat collecting plate illustrated in Fig. 1 and the solar heat collecting plate of the present invention illustrated in Fig. 2 were placed in a constant temperature bath at 20°C for 16 hours after filling their water passages with water. Next, we put it in a constant temperature bath at +80℃ for 8 hours, and as a result of examining how many cycles it takes for the seal welded joints of each solar heat collecting plate to begin to break, we found that in the case of conventional solar heat collecting plates, Breakage started at the beginning or end of seam welding after one cycle, but in the case of the solar heat collector plate of the present invention, no breakage or even a sign of this was observed even after 100 cycles.

As is clear from the results of this experiment, it will be understood that the freeze damage resistance of the solar heat collector plate having the structure of the present invention is far superior to that of the conventional structure.

As described above, the present invention provides a solar heat collecting plate that is extremely useful industrially.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional solar heat collecting plate, and FIG. 2 is a sectional view of a solar heat collecting plate of the present invention. 1.2... thin plate, 3... water passage, 4...
...Welded joint part, 5...Non-welded contact part.

Claims (1)

[Scope of utility model registration request] In a solar heat collector plate formed by locally welding two thin plates such as stainless steel plates to form a large number of water passages,
Each of the water passages is separated from other water passages adjacent to one side by welded joints between the thin plates, and separated from other water passages adjacent to the other side by non-welded contact portions between the thin plates. A solar heat collecting plate characterized by: