JPS58190653A - Solar heat collector - Google Patents

Abstract

PURPOSE:To prevent the elevation of the temperature of a heat collecting plate for the solar heat collector when the heat collector is burned without water, by a method wherein configuration storing pipes each of which becomes twisted in a stored configuration when it is heated to a high temperature are connected to both ends of a heat collecting pipe, respectively, at positions near both ends of a heat collecting fin. CONSTITUTION:The heat collecting plate is formed in such a manner that the heat collecting pipe 4 is welded to the heat collecting fin 13 which has been subjected to a surface treatment so that the upper surface thereof has a high sunlight adsorbing efficiency while the rear surface thereof has a low sunlight adsorbing efficiency. Then the configuration storing pipes 5 are connected to both ends of the heat collecting pipe 4, respectively, at positions near both ends of the fin 13. Each of the configuration storing pipes 5 becomes twisted in a stored configuration when it is heated to a high temperature, whereby when the heat collector is burned without water, each of the pipes 5 becomes twisted to make the heat collecting plate reversed to thereby cause the rear surface of the heat collecting fin 13, that is, the surface having a low sunlight absorbing efficiency, to face the sun.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat collector provided inside the solar heat collector, in which shape memory tubes are fully connected to heat collecting tubes welded to flat heat collecting fins.

A cross-sectional view of a vacuum tube type heat collector installed inside a conventional heat collector plate (llt) is shown in Figure 1.
As shown in FIG. 2, a heat collecting tube (4) was welded to a flat heat collecting fin (3).

In this case, during heat collection, sunlight is transmitted through the heat collection fins (3).
It is absorbed by the heat energy, becomes thermal energy, and flows through the heat collecting pipe (4).
However, for example, during the installation work of a heat collector, there is no heat medium inside the heat collector, and under strong sunlight, the temperature of the heat collector plate (3) may drop. The temperature rises abnormally to 200° C. or higher, which has the disadvantage of deteriorating the surface treatment layer of the heat collecting fin (3). In addition, if the heat medium circulation pump suddenly breaks down or a power outage occurs while the system is operating under strong sunlight, the heat medium in the heat collecting pipe (4) will reach a boiling state and the pressure will rise. In severe cases, the heat collector may be destroyed.

The present invention eliminates the conventional drawbacks, suppresses the temperature rise of the heat collecting plate in the dry state of the heat collector, keeps the surface treatment layer of the heat collecting fin stable, and at the same time completely suppresses the pressure rise due to boiling of the heating medium. The purpose of the present invention is to obtain a heat collector that can prevent damage to the heat collector plate.

The present invention will be explained based on the drawings.

FIG. 3 shows a sectional view of the heat collector of the present invention during dry firing, and FIG. 4 shows a perspective view of the heat collector plate of the present invention.

In the figures, the same symbols as in FIGS. 1 and 2 indicate the same parts.

In the figure, (11) is a heat collecting plate, (13) is a heat collecting fin, (5) is a shape memory tube made of an alloy whose shape is memorized,
shows.

The heat collecting plate (11) of the present invention is in contact with the heat collecting fins (13) through the heat collecting tubes (41'i), and the shape memory tubes (5 Furthermore, in the present invention, the surface of the heat collection fin (13) has a high total solar absorption rate, and the back surface is treated to have a low absorption rate. It is a shape memory tube made of an alloy such as a titanium-nickel alloy, which has a normal tube shape at a hot temperature level, but becomes a twisted tube at a high temperature such as during dry firing.

Next, the operation of the heat collecting fin of the present invention will be explained.

During heat collection, sunlight (S) hits the heat collection fins (13), which have a high absorption rate, and is converted into thermal energy, which is absorbed by the heat medium and transported. When the temperature of the heat collecting fins (13) increases and reaches the shape memory temperature of the shape memory tube (5), it becomes a screw state as shown in FIG. ). Therefore, the back surface of the heat collecting fin (13) has a low solar absorption rate, so the amount of absorbed energy is reduced, and the temperature rise of the heat collecting fin (13) is suppressed. In other words, it is impossible to suppress the temperature rise to about the shape memory temperature of the alloy.

The operation of the heat collecting tube of the present invention will be explained.

If there is no heat medium inside the heat collecting tube (4) under strong solar radiation, or if the heat medium remains stationary, the temperature of the entire heat collecting plate rises to a certain temperature, that is, the temperature of the shape memory tube (5) increases. When the shape memory temperature is reached, the shape memory tube (5) becomes twisted as shown in FIG. 5, and the back surface of the heat collecting fin (13) becomes upward.

In this way, under dry firing conditions, as shown in Figure 3, most of the sunlight is reflected because the back side of the heat collecting fin (13), that is, the side with low sunlight absorption, faces the sunlight. ,
This prevents the temperature of the heat collecting plate from rising abnormally. That is, the temperature rise can be suppressed to about the shape memory temperature of the shape memory tube (5). For example, the shape memory temperature is 100°
When the temperature is set to about C, the temperature of the heat collecting plate (13) can be suppressed to about 120°C, and the temperature, which conventionally reached 200°C or more, can be kept at a sufficiently low temperature.

As described above, according to the heat collecting tube of the present invention, it is possible to maintain the temperature of the heat collecting plate at a relatively low temperature even during dry firing, so it is possible to lower the heat resistance temperature of various used parts. In particular, surface treatment layers such as heat collecting fins do not require high heat resistance, and inexpensive oxide films can be used. This produces effects such as eliminating the risk of equipment damage or blow-out due to boiling of the heating medium.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a vacuum tube type heat collector using a conventional heat collecting tube, Fig. 2 is a perspective view of a conventional heat collecting plate, and Fig. 3 is a hollow view of a heat collector according to an embodiment of the present invention. FIG. 4 is a perspective view of the heat collecting plate of the present invention, and FIG. 5 is a perspective view of the heat collecting plate of the present invention during dry baking. P: Heat collector 4: Heat collection tube 11: Heat collection plate 13 Two heat collection fins 5: Shape memory tube Patent applicant Matsushita Electric Industrial Co., Ltd. Agent Patent attorney Isao Abe

Claims (1)

[Claims] In a heat collector in which a heat collecting plate in which a heat collecting tube is fixed to a rectangular flat heat collecting fin whose front surface has a high solar absorption rate and whose back surface has a low solar absorption rate is disposed inside, A heat collector connected to the end of the heat collecting pipe by a shape memory tube made of an alloy that memorizes the shape of a twisted pipe at high temperatures.