JPS6324232B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a method for manufacturing a fin-pipe type solar heat collector plate, which is composed of fins that absorb solar thermal energy and a pipe through which a heat medium passes to extract heat output. be.

Structure of conventional examples and their problems Generally, solar heat collectors are composed of a heat collecting plate, a transparent cover to reduce heat radiation, a heat insulating material, an outer box, etc. After sunlight passes through the transparent cover, it is absorbed by the heat collecting plate and becomes thermal energy, which heats the heat medium.

Typical cross-sectional shapes of conventional heat collecting plates are shown in Figure 1a,
It was as shown in b and c. In other words, the shape a is seen in aluminum cladding, and is typified by a manufacturing method called the roll bonding method, which has the characteristics of easy mass production and high fin efficiency of the heat collecting plate.
In the general case where water is used as a heat medium and flows through the flow path 1', there is a drawback that corrosion resistance is poor. In case of b, pipe 3' is made of aluminum plate and copper pipe.
This is the shape seen when these are combined, and is called the fin pipe type. However, since a copper tube is used as the pipe 3, although the corrosion resistance is improved compared to (a), metal corrosion is inevitable when ordinary city water is passed through. In addition, in this shape, the fins 2' and the pipe 3' are mechanically tightened and joined in order to reduce the thermal resistance between the fins 2' and the pipe 3', improve heat conduction, and increase heat exchange efficiency. The fin 2' material is often oxidized and distorted due to local temperature rise, and to prevent this, the entire fin 2' must be uniformly bonded. In addition to requiring large heating equipment, copper pipes were generally expensive. c is two steel plates 4' that have been press-molded with a waterway pattern in advance.
are seam-welded and laminated together to form a flow path for the heat medium. Although steel is cheaper than aluminum or copper, it is not suitable for practical use due to its significantly inferior corrosion resistance, and it is not suitable for ordinary practical use. In this case, stainless steel is used, which has disadvantages such as being as expensive as a and b and also being heavy. Even in this case, metal corrosion cannot be avoided when water is passed through. In addition, there are plastic heat collecting plates manufactured by blow molding, injection molding, etc. using inexpensive resin materials such as polyethylene resin, and the risk of corrosion is greatly reduced. In addition to being inferior in durability compared to
It had the disadvantage of low thermal conductivity and poor heat transfer efficiency to the heat medium.

Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides an inexpensive solar heat collection plate that is free from corrosion even when water is passed through it, does not require excessively high-temperature work, is easy to manufacture, and has good heat exchange efficiency. The purpose is to provide a manufacturing method for.

Structure of the Invention In order to achieve this object, the present invention heats and expands a resin pipe within a cylindrical space formed in the fin, and brings the resin pipe into close contact with the cylindrical space.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 2 to 11 show steps of a manufacturing method according to an embodiment of the present invention. 1 is a metal fin, and 2 is a cylindrical space forming jig. First, as shown in FIGS. 2 and 3, a flat plate of metal fin 1 is placed on a jig 2 for forming a cylindrical space. Next, force is applied from above along the jig 2 so that the jig 2 serves as a fulcrum (Fig. 4). When a predetermined cylindrical space 4 is formed, a force is applied in the opposite direction to return the metal fin 1 to its original state (FIGS. 5 and 6). Pull out the cylindrical space forming jig 2 (FIG. 7). Ready-made resin pipe 3
is inserted into the formed cylindrical space 4 (Fig. 8).
Here, the inner diameter of the cylindrical space 4 is designed to be slightly larger than the outer diameter of the resin pipe 3 to be inserted. Next, one end of the resin pipe 3 is closed, and a hydraulic pump is connected to the other end. Next, when the metal fin 1 is heated with an infrared lamp, the portion of the resin pipe 3 inserted into the metal fin 1 is heated. When the resin pipe 3 is thus heated to the deformation temperature, the hydraulic pump is activated to apply pressure inside the resin pipe 3. As a result, the resin pipe 3 expands, and when cooled under pressure, the resin pipe 3 is tightly joined to the cylindrical part, completing the heat collecting fin (Figs. 9 to 11).
figure). At this time, as shown in FIG. 12, if an air bubble escape hole 5 is provided in the upper part of the cylindrical space 4, when the resin pipe 3 expands, the air between the resin pipe 3 and the cylindrical part can be easily removed. This makes it possible to eliminate uneven gaps and achieve complete adhesion.

Effects of the Invention According to the present invention, by heating the resin pipe to soften it and expand it, it can be brought into close contact with the cylindrical part of a predetermined shape of the fin, which eliminates the need for advanced welding and joining techniques as in the past. First, there is no distortion of the fins, and solar heat collecting plates can be manufactured in a short time. In addition, the desired purpose can be achieved using inexpensive ready-made resin pipes without the need for equipment investment such as special molds, so we can provide inexpensive solar heat collecting plates and, by extension, inexpensive solar heat collectors. It is something that can be done.

[Brief explanation of the drawing]

Figures 1 a to c are cross-sectional views showing conventional examples, and Figures 2 to 2 are cross-sectional views showing conventional examples.
FIG. 11 is a process sectional view showing an embodiment of the present invention;
FIG. 12 is a perspective view of the metal fin. 1...Metal fin, 2...Jig for forming a cylindrical part,
3... Resin pipe, 4... Cylindrical space, 5... Air bubble escape hole.

Claims (1)

[Claims] 1. After inserting a resin pipe having an outer diameter slightly smaller than the inner diameter of the cylindrical space into the cylindrical space of a metal fin that has a cylindrical space formed in a part thereof, the resin pipe is inserted into the cylindrical space. A method for manufacturing a solar heat collector plate, which involves pressurizing the inside of the pipe while heating it to the resin softening temperature, expanding the resin pipe within the cylindrical space, and bringing it into close contact with the inner surface of the cylindrical space. 2. The method for manufacturing a solar heat collecting plate according to claim 1, wherein small holes for air bubble escape are provided in the cylindrical space.