JPS5937417B2 - Heat collecting part of solar collector and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat collector used, for example, in a solar air conditioning, heating, and hot water supply system that utilizes solar heat as hot water, and in particular to an improvement in its heat collecting portion and a manufacturing method thereof.

First, a conventional solar collector will be explained with reference to FIGS. 1 to 4.

In these figures, 1 is a box-shaped outer box made of a steel plate, etc., 2 is a transparent cover made of plate glass or the like that airtightly closes the top opening of the outer box 1, and 3 is a rectangular flat plate made of aluminum. In the heat collecting plate to be produced, a groove 5 having a circular cross section with a part cut out is formed extending in the longitudinal direction in the center of the short side, and plate-shaped fins 4 are connected to each end of the groove 5. The extrusion molding is made by having one.

Reference numeral 6 denotes a cylindrical heat collecting pipe made of a material such as a steel pipe which has a projection 8 at one end and is pressed into the groove 5 of the heat collecting plate 3, and is closed at both ends. Transport medium 9
A suitable amount is included.

The portion joined to the groove 5 is an evaporation section 7, and the protrusion 8 is a condensation section.

10 is a header pipe made of material such as steel pipe through which water flows;
A plurality of connection holes 11 are drilled in one row on one side, and the heat collecting tubes 6 are connected to each of the connection holes 11 by inserting the condensing portions 8 thereof at right angles.

The header pipe 10 and the condensing section 8 are connected by welding such as brazing.

The heat collecting plate 3, the heat collecting pipe 6, and the header pipe 10 constitute a heat collecting section, which is horizontally installed below the transparent cover 3 with a space in the outer box 1.

Reference numeral 12 denotes a heat insulating material made of glass wool or the like placed between the outer box 1 and the heat collecting plate 3 and around the header pipe 10.

A conventional solar collector is configured as described above, with an outer box 1
The side where the header pipe 10 is located is raised and inclined, and is installed outdoors.

Therefore, sunlight passes through the transparent cover 2 and hits the fins 4 of the heat collecting plate 3, where it is absorbed and converted into heat by the heat collecting tube 6.
The evaporation section 7 of is heated.

Then, the heat medium 9 in the evaporation section 7 is heated and boils, and the temperature is kept constant by the latent heat of vaporization, and the evaporation is rapidly diffused and condensed and liquefied in the condensation section 8 where the temperature and vapor pressure are low.

Since the heat collecting pipe 6 is installed at an angle with the condensing part 8 facing upward, the liquid heat medium 9 condensed and liquefied in the condensing part 8 flows down inside the heat collecting pipe 6 by gravity and returns to the evaporating part 7.

When the heat medium 9 liquefies in the condensing section 8, it releases latent heat of condensation, and this heat increases the temperature of the water flowing in the header pipe 10.

Heat loss from the heat collecting plate 3 is reduced by the transparent cover 2 and the heat insulating material 12, heat loss from the header pipe 10 is also reduced by the heat insulating material 12, and water in the header pipe 10 is prevented from freezing at night during winter. It is measured.

Note that when the amount of solar radiation decreases and the temperature of the fins 4 falls and the temperature of the evaporator 7 becomes lower than the water temperature in the header pipe 10, condensation of the heat medium 9 occurs in the evaporator 7, but the temperature is higher than that of the evaporator 7. The heat medium 9 cannot move to the condensing part 8 located in the position, the reverse cycle is not established, and therefore heat radiation from the header pipe 10 to the fins 4 cannot occur.

However, when the heat collecting pipe 6 is directly inserted into the header pipe 10 and welded and joined as described above, the temperature of the heat collecting pipe 6 becomes considerably high during brazing, so it is necessary to use a heat medium 9 with high heat resistance that can withstand that temperature. However, after welding the heat collecting pipe 6 to the header pipe 10, the heat medium is sealed and the end portions are sealed, and the assembly is troublesome and time-consuming.

Furthermore, unless the header pipe 10 is made thicker, the heat transfer area of the condensing section 8 cannot be made large enough to ensure sufficient heat exchange between the heat medium 9 and the water.

This invention was made in order to eliminate the above-mentioned drawbacks, and aims to provide a solar heat collector that does not allow sufficient heat exchange between the heat medium in the heat collecting tube and the heat medium such as water in the header tube, and is easy to assemble. purpose.

The details of this invention will be explained below with reference to illustrated examples.

FIG. 5 is a cross-sectional view showing one embodiment of the present invention, and in this figure, 4 to 9, including parts not shown, are completely the same as those of the conventional example.

Reference numeral 10 denotes a header pipe made of a straight steel pipe through which water flows, and one side thereof has a plurality of connecting holes 11 whose ends are burred in a row and whose inner diameter is somewhat larger than the outer diameter of the heat collecting pipe 6. It is set up.

Reference numeral 13 denotes a short tubular branch pipe whose outer diameter is equal to the inner diameter of the connection hole 11 and whose inner diameter at one end is equal to the outer diameter of the heat collecting pipe 6; is brazed to the boundary between the evaporating section 7 and the condensing section 8 of the heat collecting tube 6, and the other end is similarly brazed to the connecting hole 11.

Note that the tip of the condensing section 8 is designed to be located deep inside the header pipe 10.

The order of assembling the heat collecting section having such a configuration is to first close the end of the heat collecting pipe 6 on the side that will become the condensing section 8, and then close the end of the heat collecting pipe 6 on the side that will become the condensing section 8.
The narrowed end of 3 is brazed and joined to the boundary between the evaporation section 7 and the condensation section 8 of the heat collection tube 6, and then the heat medium 9 is sealed in the heat collection tube 6, and the end on the evaporation section 7 side is closed. Thereafter, the other end of the branch pipe 13 and the connection hole 11 of the header pipe 10 are brazed and welded, and the heat collecting plate 3 is press-fitted and fixed into the evaporation part 7 of the heat collecting pipe 6.

Alternatively, after closing the side end of the evaporator 7, the heat collecting plate 3 is press-fitted and fixed into the evaporator 7 of the heat collecting pipe 6, and the other end of the branch pipe 13 and the connection hole 11 of the header pipe 10 are brazed and welded. .

Also, a branch pipe 13 is located at the boundary between the condensing section 8 and the evaporating section 7 of the heat collecting pipe 6.
The narrowed ends of the header tube 10 are joined by brazing, and then the heat medium 9 is sealed in the heat collecting tube 6, both ends are closed, and the header tube 10 and the heat collecting plate 3 are assembled by one of the methods described above.

If necessary, the heat collecting pipe 6 is
The narrowed end of the branch pipe 13 is joined by brazing at the boundary between the condensing part 8 and the evaporating part 7, and then the heat medium 9 is sealed in the heat collecting pipe 6, and then the other end of the branch pipe 13 and the header pipe 10 are sealed. The heat collecting pipe 6 and the header pipe 10 may be assembled by welding the connecting holes 11 of the heat collecting pipe 6 and the header pipe 10.

In the heat collecting section of the solar heat collector configured as described above, the condensing section 8 of the heat collecting pipe 6 can be made sufficiently long according to the length of the branch pipe 13.

Further, the movement of the heat medium 9 in the heat collecting tube 6 is the same as in the conventional example described above, and heat is released in the condensing section 8.

The water flowing in the header pipe 10 falls directly into the tip of the condensing section 8 and absorbs the heat of condensation.

Further, since the heat collecting section is installed with the header pipe 10 side highly inclined, the water in the branch pipe 13 is constantly replaced with the water in the header pipe 10 by natural convection, and heat is exchanged with the condensing part 8.

Although the header pipe 10 and branch pipe 13 are welded during assembly, the heat collecting pipe 6 is not directly heated, so the temperature rise is small and there is no deterioration of the heat medium 9 or dangerous pressure rise.

FIG. 6 shows another embodiment of the method for connecting three pipes, the heat collecting pipe 6, the branch pipe 13, and the header pipe 10.
is welded to the connection hole 11 of the header pipe 10 in advance.

During assembly, the heat collecting pipe 6 is inserted into the branch pipe 13, and both are tied together with an elastic tube 15 such as a rubber tube and fixed with a band 16 or the like.

In this case, unlike in welded joints, there is no heating, so there is no thermal problem on the heat medium 9, and the heat collecting tube 6 can be easily replaced later.

Figures 7 and 8 show a condensing part 8 (!) which further improves heat exchange with water, and is inserted onto the center line of the outer periphery of the heat collecting pipe 6 from about the middle of the condensing part 8 to the tip. A partition plate 14 is attached to change the flow of water within the header pipe 10.

As shown in FIG. 8, part of the water flows directly through the header pipe 10 through the gap between the partition plate 14 and the header pipe 10, and part of the water flows directly through the header pipe 10, where the flow direction is changed by the partition plate 14 and reaches the condensing section. The entire periphery of the condensing section 8 that goes around the root of the condensing section 8 [the boundary with the evaporating section γ] becomes a forced convection area, which further improves heat exchange with the water, and the partition plate 14 prevents heat transfer to the outside of the condensing section 8. The area will also increase.

As for the assembly order, first attach the heat collecting pipe 6, the branch pipe 13 and the partition plate 14.
After joining, the heat medium 9 is sealed, and the branch pipes 13.
:! : Join the header pipe 10.

By the way, in the above description, the present invention has been described with respect to the heat collecting part of a flat plate collector, but it goes without saying that it can be used as a heat collecting part of a cylindrical vacuum collector in which a heat collecting plate is housed in a vacuum-insulated glass tube.

As explained above, this invention connects a header pipe through which a heat medium flows and a heat collection pipe in which a heat medium that exchanges heat with the heat medium of the header pipe is sealed, through a branch pipe, and connects the branch pipe and the heat collection pipe. After welding and joining the
After that, the simple structure and method of welding and joining the branch pipe and header pipe has the effect of increasing the heat exchange area of the condensing section, ensuring good heat exchange between both heat carriers, and simplifying assembly. .

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional solar collector, Fig. 2 is a plan view of the heat collecting part of the collector shown in Fig. 1, Fig. 3 is an enlarged sectional view taken along FIG. 2 is an enlarged sectional view taken along IV-IV, FIG. 5 is a sectional view showing a lost case of this invention, and FIG.
The figure is a sectional view showing another actual example of the present invention, FIG. 7 is a sectional view showing still another actual example of the invention, and FIG. 8 is a partially sectional plan view of FIG. 7. In the figure, 3 is a heat collecting plate, 4 is a fin, 6 is a heat collecting pipe, 7 is an evaporator, 8 is a condensing part, 9 is a heat medium, 10 is a header pipe, 1
3 is a branch pipe, and 14 is a partition plate. Note that the same reference numerals in each figure indicate the same or similar parts.

Claims (1)

[Scope of Claims] 1. A condensing unit consisting of an evaporation part that occupies most of the whole and collects solar heat, and a condensation part that includes one end, in which a heat medium for heat transfer is sealed, and both ends are closed. The condensing section of the heat collecting tube is composed of a heat pipe and a header pipe which has a branch pipe which projects outward and is connected to the inside, and through which a heat medium to exchange heat with the heat medium in the heat collecting pipe flows. is inserted from the end face of the branch pipe until it is located in the header pipe, and the heat collection pipe and the branch pipe are connected. 2. The heat collecting part of the solar collector according to claim 1, wherein the branch pipe and the heat collecting pipe are joined by an elastic pipe. 3. Consisting of an evaporation section that collects solar heat, which occupies most of the whole, and a condensation section that includes one end, a heat collecting tube with a heating medium for heat transfer sealed inside and closed at both ends, and a condensation section that protrudes to the outside. , has a branch pipe whose insides are connected, and further includes a header pipe having a heat medium therein which exchanges heat with the heat medium in the heat collecting pipe, and the condensing part of the heat collecting pipe is inside the header pipe. inserted from the end face of the branch pipe until the heat collecting pipe and the branch pipe are connected to each other, and arranged inside the header pipe at a portion where the condensing section is located;
A heat collection section of a solar collector, characterized in that it is provided with a partition plate that changes the flow direction of the heat medium in the header pipe. 4. A heat collecting tube with both ends closed and a heat medium sealed inside is inserted into a header pipe with protruding branch pipes through which a heat medium flows, and the heat collecting part of a solar collector is welded. , first, the heat collecting pipe and the branch pipe are joined by welding, a heat medium is sealed and closed in the heat collecting pipe, and then the branch pipe and the header pipe are joined by welding. A method for manufacturing a heat collecting part of a solar collector.