JPS60149848A - Heat exchanger for use in solar collector - Google Patents

Abstract

PURPOSE:To form the titled heat exchanger for use in the focusing type solar collector excellent in a heat collecting performance and an appearance by providing a heat collecting member, which collects solar light reflected by a concave mirror on the focusing surface of the groove type concave mirror, is provided along the longitudinal direction on the mirror axis. CONSTITUTION:Heat collecting panels each of which is constituted by superimposing a plurality of heat collecting plates each being applied with a selective absorbing membrane on one surface thereof, are disposed so that the back sides (the sides of metal tubes) face each other on the mirror axis of the groove type concave mirror. That is, such heat collecting panels C and C' are fitted to header tubes C4 and C4. As a result, solar light can be absorbed uniformly and efficiently from the front sides of respective heat collecting panels C and C', that is, both surfaces of the heat collecting member X, and hence, excellent heat collection performance and excellent appearance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concentrating solar collector heat exchanger having excellent heat collection performance and appearance.

As shown in Fig. 1, a concentrating type solar collector heat exchanger generally has a pipe B formed by applying a selective absorption film such as black Cr on the outer circumferential surface of the groove-type concave mirror A in the longitudinal direction on the mirror axis line. death,
This is a heat exchanger for a solar collector designed to collect sunlight reflected by the concave mirror A, and a relatively large amount of heat collection (for example, about three times that of a fixed heat collection panel method) can be obtained with a small installation area. There is an advantage. Of course, in the case of this method, it is necessary to make the concave mirror A follow the movement of the sun.
Although it has the disadvantage of requiring the installation of optical sensors and drive motors, making the equipment cost somewhat high, as mentioned above, the advantages of requiring less installation space and a large amount of heat collection are attracting attention, and it is widely used for everything from factories to homes. It is being adopted.

However, the desire for improved heat collection performance has become even stronger, and the inventors of the present invention have also conducted repeated studies to meet these demands. As the first step, the first
In place of the pipe B shown in the figure, we considered arranging a heat collecting member mainly composed of a heat collecting panel C, which is advantageous in terms of light receiving area. That is, the heat building member X is composed of a set of heat collecting panels C and two ladder pipes C4 and C4'. Specifically, a metal tube C3 is welded to the center longitudinal direction of the lower surface of the metal fin C2, and both ends C3' and 'C3' of the tube C3 are welded.
Black Cr plating is applied to both sides of each heat collecting plate C1 formed to slightly protrude from the longitudinal end of the fin, and the heat collecting plate (CI) after the plating treatment is applied to the side edge C of each fin C2.
A plurality of metal tubes (four in the figure) are arranged in a row so that the metal tubes 2' are in contact with each other to form a heat collecting panel C, and both ends 03' of each metal tube.

Header pipes C4 and C4' are respectively connected to C3'. However, in this case, when looking at the adhesion status of the black Cr plating on each heat collecting plate C1, as shown in Fig. 4 (side view of the heat collecting plate), the welded part of the metal tube C3 (dotted line area in the figure, D' ) was found to have no black Cr plating attached to it. Therefore, in Figure 3, the heat collection efficiency on the back side of the heat collection panel C (metal tube side) cannot be said to be sufficient.
It was also found that the appearance deteriorated.

Therefore, the present inventors developed a combination of a heat collection plate (C1) and a selective absorption film that can uniformly deposit a high-performance selective absorption film (for example, black Cr, black N1, etc.) on the entire back side of the heat collection panel C. In order to find a solution, various studies were carried out, especially from the viewpoint of materials, but it was not possible to find a solution that was satisfactory within a practical range.

Under these circumstances, the present invention was completed as a result of intensive studies to provide a condensing type solar collector heat exchanger with excellent heat collection performance and appearance. A heat exchanger for a solar collector in which a heat collecting member is provided along the longitudinal direction of the mirror axis on the light surface side to collect sunlight reflected by the concave mirror, and the heat collecting member is a heat collecting member formed of a band-shaped flat plate. From a heat collecting panel constructed by stacking and arranging a plurality of heat collecting plates each made by joining at least one metal tube through which a heat exchange medium to absorb heat from the fins flows in the longitudinal direction of the metal fins. The gist is that the heat collecting panels are arranged on the mirror axis of the groove-type concave mirror, facing each other so that the respective metal tubes are on the inside.

The configuration and effects of the present invention will be explained below based on the drawings of the embodiments. Figures 5 to 8 are schematic explanatory diagrams illustrating some of the heat exchangers of the present invention, and the basic configuration of the heat exchanger in any of the embodiments is as shown in Figures 2 and 3. There is no estate that is different from a vessel.

This embodiment is particularly different from the conventional example, and is characterized by the fact that the heat collecting panels, which are constructed by stacking and arranging a plurality of heat collecting plates each having a selective absorption film on one side, are connected to each other on the back side ( The metal tube side) are arranged so that they face each other on the mirror axis of the grooved concave mirror. That is, the embodiment shown in FIG.
Connect such heat collecting panels c, c' to each header pipe C4
, C4 is an example of a facing arrangement. As a result, sunlight can be absorbed evenly and efficiently from the front side of each heat collecting panel, panels c and c', that is, from both sides of the heat collecting member Heat collection performance and appearance were achieved. Furthermore, since the heat collecting plate C1 can be an inexpensive heat collecting plate employed in the above-mentioned heat collecting panel fixing method, it can be said to be advantageous in terms of material cost. By the way, although the embodiment shown in FIG. 5 is one in which the heat collecting panels c and c' are simply arranged facing each other, it is also an embodiment that has room for improvement. That is, in this embodiment, two sets of header pipes are required, and the number of manufacturing steps is increased because it is also necessary to connect the header pipes, and furthermore, the thickness between the heat collecting panels c and c', that is, the heat collecting member The thickness of X is the second
゜Since it is about twice as large as the example in Figure 3, the concave mirror A' must also be larger, which increases the manufacturing cost.
It has one aspect that makes it difficult to implement as a general-purpose device.

Therefore, the inventors of the present invention conducted further studies in order to create a heat exchanger that is sufficiently practical in terms of manufacturing cost, and by devising the method of arranging the heat collecting panels facing each other as shown in FIG. 5, almost satisfaction was achieved. An example has been reached. This example is the 6th and 7th
As shown in the figure, heat collecting panels c and c' similar to those shown in Fig. 5 with selective absorption membranes uniformly adhered only to the front side are connected to metal tubes (C3°C3,...), (C3', C3 ',
...) are used as a common perpendicular line, and the back sides (metal tube side) of the concave mirror A are arranged to face each other so that the perpendicular line coincides with the mirror axis of the concave mirror A.

Therefore, only one set (two) of header pipes is required, and there is no disadvantage that the number of manufacturing steps increases as in the case of the example in Fig. 5, and the thickness l' between the heat collecting panels c and c' is also 2°3. Since there is almost no difference compared to the case shown in the figure, it is possible to maintain a compact state. In any case, it is economically very advantageous because manufacturing costs can be kept to a minimum.

Although sufficient practical effects can be enjoyed with the configuration examples shown in Figs. 6 and 7 above, as is clear from Fig. 6, there are no selective absorption membranes at both the upper and lower ends of the heat exchanger (in the figure). E
, E') remain, and it is possible to make the present invention even more valuable by improving this part. An example of the improvement means will be explained below. That is, as shown in FIG. 8 (schematic cross-sectional view of essential parts), the heat collecting plates ci obtained by longitudinally welding the metal tube C3 at a position slightly shifted from the center of the lower surface of the metal fin C2 are attached to the sixth and seventh heat collecting plates ci. By arranging them facing each other as shown in the figure,
The above-mentioned portions (E and E' in FIG. 6) where there is no selective absorption film can be eliminated.

The embodiments shown in FIGS. 5 to 8 above merely show some representative examples of the present invention, and are not intended to limit the present invention. It is within the technical scope of the present invention to appropriately change the design of the shape and dimensions of the tube, the type of selective absorption membrane, the facing arrangement of the heat collecting panels, etc. For example, although only welding is used as an example of a method for joining metal tubes and heat collecting plates,
Brazing or soldering may be done by brazing or soldering, or a fitting method as shown in Figure 9 may be used.In addition, when arranging heat collecting plates in a stacked manner, the side edges of each fin overlap each other as an example. However, if you are a little patient with the poor appearance, there is technically no problem even if you are a little far apart.

Since the present invention is configured as described above, it is an object of the present invention to provide a concentrating type heat exchanger for a solar collector, which has excellent heat collection performance and appearance, and can easily improve economical efficiency as required. Now I can do it.

[Brief explanation of drawings]

Figure 1 is a schematic perspective view of a concentrating type solar collector heat exchanger using pipes, and Figures 2 to 4 show conventional concentrating type solar collector heat exchangers using heat collecting panels.
Fig. 2 is a schematic perspective view, Fig. 3 is a sectional view taken along the n+-nt line in Fig. 2, Fig. 4 is a side view of the heat collecting plate, and Figs. 5 to 8 schematically explain the heat exchanger of the present invention. Figure 5 is a diagram corresponding to Figure 3 for the basic embodiment, Figure 6 is a diagram corresponding to Figure 3 for other embodiments, Figure 7 is a schematic plan view of Figure 6, and Figure 8 is a diagram corresponding to Figure 3 for the basic embodiment. The figure shows a preferred embodiment of the invention.
FIG. 9 is an explanatory diagram showing a joining method by fitting a metal tube and a heat collecting plate. A... Groove concave mirror B... Pipe c, c'... Heat collection panel CI... Heat collection plate C
2...Metal fin C3...Metal tube C4, C
4'... Header pipe X... Heat collecting member applicant Kobe Steel, Ltd. Figure 1 Figure 6 Figure 7

Claims (1)

[Claims] A heat exchanger for a solar collector in which a heat collecting member that collects sunlight reflected by the concave mirror is provided on the light collecting surface side of a groove-type concave mirror along the longitudinal direction of the mirror axis, the heat collecting member comprising: 8. A heat collecting plate formed by joining at least one metal tube through which a heat exchange medium to absorb heat from the fins flows in the longitudinal direction of the heat collecting fins, which are flat belt-shaped heat collecting fins.8. The heat collecting panel is constructed by stacking several heat collecting panels, and the heat collecting panels are arranged on the mirror axis of the grooved concave mirror, facing each other so that the respective metal tubes are on the inside. Features of heat exchanger for solar collector.