JPS629483Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a solar heat collection tube used in a solar heat utilization system.

Conventionally, this type of solar heat collecting tube has a structure in which a metal heat collecting pipe is passed through a vacuum glass tube in an airtight manner. The collected heat heats the heat collecting pipe, and the heat from the heat collecting pipe is conducted to the heat medium flowing inside, thereby heating the heat medium. Furthermore, since the inside of the glass cylinder is in a vacuum state during such a heat collecting action, heat dissipation from the heat collecting pipe is prevented by the heat insulating layer formed by the vacuum space. Therefore, the heat of this heat collection pipe is effectively conducted to the heat medium, and its heat collection performance is high.

By the way, in such a heat collecting tube, the glass tube is generally long, so when the heat collecting pipe is passed through the glass tube, it is necessary to hold the heat collecting pipe inside the glass tube. There is. Therefore, conventionally, a metal holder is attached to the heat collecting pipe, the tip of which is in elastic contact with the inner surface of the glass tube, and this holder is used to hold the heat collecting pipe on the tube axis of the glass tube. It's summery. but,
During the heat collecting action, a difference in thermal expansion occurs between the heat collecting pipe and the glass cylinder due to the temperature rise of the heat collecting pipe and the glass cylinder. For this reason,
Due to this difference in thermal expansion, the holder slides while rubbing against the inner surface of the glass tube, which causes a problem in that the inner surface of the glass tube is damaged.

Furthermore, some holders have a roller attached to the tip of a leaf spring, and the roller is brought into elastic contact with the inner surface of the glass cylinder by the leaf spring. However, when this type of roller is slid in a direction opposite to the deflection direction of the leaf spring, the rolling resistance of the roller against the inner surface of the glass tube increases, which may cause scratches on the inner surface of the glass tube. There were times when I would add it.

This idea was made based on these circumstances, and its purpose is to prevent the inner surface of the glass cylinder from being scratched by the holder no matter which direction it slides along the axis of the tube. Our purpose is to provide a heat collecting tube.

That is, in this invention, the above-mentioned holder is provided with a plurality of support legs made of a pair of spring members that protrude from the heat collecting pipe toward the inner surface of the glass cylinder and are bent in opposite directions along the tube axis of the glass cylinder, and these legs. The device is characterized by comprising rollers that are attached to the tips of the support legs and come into elastic contact with each other by the elastic force of the support legs, and that are movable on the inner surface of the glass cylinder along the tube axis.

An embodiment of this invention will be described below with reference to FIGS. 1 to 4.

In the figure, 1 is a glass tube, and both ends of the glass tube are covered with metal end caps 2.
A and 2b are airtightly closed. A heat collecting pipe 3 is disposed inside the glass cylinder 1. The heat collecting pipe 3 is made of, for example, a copper pipe, and passes through the end caps 2a, 2b in an airtight manner to form a passage for the heat medium. In addition, 4,4
is a joint flange of the heat collecting pipe 3. The heat collecting pipe 3 passes through the end caps 2a and 2b in an airtight manner, and as shown in FIG. has been done. This expansion joint 5 is composed of, for example, a bellows or the like, and the heat collecting pipe 3
It has a double pipe structure, and one end is hermetically joined to the end cap 2a, and the other end is hermetically joined to the outer surface of the heat collecting pipe 3. Therefore, the expansion joint 5 can absorb the thermal expansion and contraction of the glass tube 1 and the heat collecting pipe 3. Further, 6 is an exhaust pipe. This exhaust pipe 6 is connected to a vacuum pump, and is sealed when the inside of the glass cylinder 1 is evacuated and reaches a predetermined degree of vacuum.

A selective absorption film is formed on the outer surface of the heat collecting pipe 3. This selective absorption film is made of, for example, an oxide film of chromium or the like, and although it absorbs well in the wavelength region of sunlight, it has the property of emitting only a small amount in the infrared wavelength region. Therefore, when the heat collecting pipe 3 is irradiated with sunlight, this sunlight is well absorbed by the selective absorption film, and the heat collecting pipe 3 is effectively heated. Although not shown in the drawings, a reflecting plate may be arranged outside the glass tube 1 to reflect sunlight and focus the reflected light on the heat collection pipe.

A holder 7 is provided on the heat collecting pipe 3 within the glass cylinder 1. This holder 7
The base ring 8 is fitted and attached to the heat collecting pipe 3, and the base ring 8 is provided with support legs 9. These support legs 9 are equally spaced on the base ring 8, with their base ends attached to the base ring 8 and their tips protruding toward the inner surface of the glass tube 1. In addition, 10, 10 is a stopper. As shown in FIG. 3, each support leg 9 is composed of a pair of spring members, such as leaf springs 11a and 11b. These leaf springs 11a, 11b are bent in opposite directions along the tube axis of the glass tube 1, and these leaf springs 11a, 11b are opposed to each other. A roller 12 is provided at the tip of each support leg 9, that is, at the free end of the leaf springs 11a, 11b.
... are installed respectively. These rollers 1
2 are brought into elastic contact with the inner surface of the glass tube 1 by the elastic force of the respective support legs 9, and are able to freely roll on the inner surface of the glass tube 1 along the tube axis. Therefore, the heat collecting pipe 3 is held on the tube axis within the glass tube 1 by the rollers 12 of the holder 7 coming into elastic contact with the inner surface of the glass tube 1. Further, the rollers 12 are made of a heat-resistant material, such as a porcelain material.

The solar heat collecting tube with such a configuration uses the heat obtained by absorbing sunlight with the heat collecting pipe 3 to the heat collecting pipe 3.
The heating medium is heated by conducting heat to the heating medium flowing inside the glass cylinder 1, and the heat dissipation from the heat collecting pipe 3 is prevented by the heat insulating layer formed by the vacuum space inside the glass tube 1. The heat of the heat pipe 3 is effectively conducted to the heat medium, and its heat collection performance is high. In this embodiment, the glass tube 1
Since the holder 7 that holds the heat collecting pipe 3 inside is configured with rollers 12 that come into elastic contact with the inner surface of the glass tube 1, the glass tube 1 is
Even if thermal expansion occurs between the heat collecting pipe 3 and the heat collecting pipe 3, these rollers 12 roll without rubbing against the inner surface of the glass tube 1, and do not damage the inner surface of the glass tube 1. . Further, according to this embodiment, each support leg 9 of the holder 7 is composed of a pair of opposing springs 11a and 11b that are curved in opposite directions along the tube axis, so that the roller 12 When the rollers 12 roll on the inner surface of the glass tube 1 due to the thermal expansion difference, the rollers 12 roll smoothly no matter which direction they try to roll along the tube axis. can be done. That is, as shown in Figure 4,
When the heat collecting pipe 3 expands in the direction of the arrow a with respect to the glass tube 1, the plate spring 11a on the side in the direction a, which constitutes the support leg 9, is easily bent, and heat is collected in the direction of the arrow b, opposite to the direction a. If pipe 3 expands, b
Since the plate springs 11b in both directions are easily deflected, the rollers 12 can smoothly roll in either direction. As a result, scratches on the inner surface of the glass tube 1 due to the rolling of the rollers 12 can be reliably prevented.

Note that this invention is not limited to the above embodiment. For example, as shown in FIG. 5, reinforcing springs 13a and 13b for the pair of leaf springs 11a and 11b constituting the support leg 9 may be provided on the inside of the curve, respectively. Furthermore, the supporting legs 9 are not necessarily formed by having the leaf springs 11a, 11b facing each other, but instead are formed by having the leaf springs 14a, 14 facing each other, as shown in FIG.
b may be arranged in series. Furthermore, when holding the heat collecting pipe within the glass cylinder, a plurality of holders may be used.

As explained above, this invention uses a plurality of supports made of a pair of spring members that protrude from the heat collecting pipe toward the inner surface of the glass tube and are bent in opposite directions along the tube axis of the glass tube. It is characterized by comprising legs, and rollers that are attached to the tips of the support legs and are brought into elastic contact with the inner surface of the glass cylinder along the tube axis by the elastic force of the support legs, so as to be able to roll freely along the tube axis. be. Therefore, even if there is a difference in thermal expansion between the glass tube and the heat collecting pipe, the rollers are rolled without rubbing against the inner surface of the glass tube, thereby preventing the inner surface of the glass tube from being scratched by the holder. can do. In addition, since the supporting legs are made up of a pair of spring members curved in opposite directions, the rollers can roll smoothly in either direction along the tube axis, and the glass can be fixed more securely. This can prevent scratches on the inner surface of the cylinder.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of this invention, with Figure 1 being a side view of the entire heat collecting tube, and Figure 2 being a side view of the entire heat collecting tube.
Cross-sectional view in the middle of the figure, Figure 3 is in Figure 1 -
FIG. 4 is a cross-sectional view taken along the line in FIG. 3, and FIGS. 5 and 6 are cross-sectional views of a holder showing other embodiments of this invention. 1... Glass tube, 3... Heat collection pipe, 7... Holder,
9...Support legs, 11a, 11b, 14a, 14b...
Leaf spring (spring material), 12...roller.

Claims (1)

[Scope of utility model registration request] A glass tube with the end of the glass tube hermetically closed and a vacuum inside, a heat collecting pipe that is arranged to pass through the glass tube airtightly and forming a passage for the heat medium, and a heat collecting pipe provided in the heat collecting pipe. and a holder for holding the heat collecting pipe within the glass tube, the holders are provided protruding from the heat collecting pipe toward the inner surface of the glass tube, and are attached to each other along the tube axis of the glass tube. A plurality of support legs made of a pair of spring members curved in opposite directions, and a plurality of support legs that are attached to the tips of these support legs and are brought into elastic contact by the elastic force of each support leg, and are rolled onto the inner surface of the glass cylinder along the tube axis. A solar heat collection tube characterized by being composed of a freely movable roller.