JP2001241777A - Heat absorbing tube and solar heat collector having the heat absorbing tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat absorbing tube capable of shortening a working time without bringing about an electrolytic corrosion and a solar heat collector having the tube. SOLUTION: The heat absorbing tube is opened at both ends and has a square shape in a longitudinal section in an installed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat absorbing tube and a solar heat collector provided with the heat absorbing tube.

[0002]

2. Description of the Related Art A solar heat collector heats a heat medium using solar heat as a heat source. Specifically, sunlight is applied to a pipe built in the solar heat collector, and a heat medium is applied to the pipe. Heat is collected by passing water through.

FIGS. 8A and 8B show devices incorporated in a conventional solar heat collector. FIG. 8A is a perspective view of a heat collecting plate, FIG. 8B is a partially exploded perspective view of the heat collecting plate, and FIG. FIG. 2 shows a sectional view of the tube. As shown in FIG. 8A, a heat collecting plate 5 is built in the solar heat collector, and the heat collecting plate 5 includes a lower horizontal tube 2 serving as an inlet for a heat medium and a solar heat collector 5. It is manufactured by connecting a vertical pipe that receives the heat and heats the heat medium and an upper horizontal pipe 2 that serves as an outlet of the heat medium. FIG. 8B
As shown in FIG. 8, a fin plate 4 for absorbing more solar heat is brazed to the vertical pipe 3.
As shown in (c), the fin plate 4 is provided with a recess so as to enhance the adhesion to the vertical pipe 3.

FIG. 9 is an exploded perspective view showing a conventional solar heat collector. The heat collecting plate 5 is placed in the box 6 via the heat insulating material 7 and connects the horizontal pipe 2 to the box 6 through the inlet / outlet joint 23.
Project outside. Since the upper surface of the box 6 is open, it is covered with a transparent plate 8 so that rainwater or the like does not enter the inside of the box 6, and is fixed with a retainer 22. The completed solar heat collector 1 on the set in this way is as shown in FIG. 10 and is installed in a place where sunlight is applied.

FIG. 11 is a schematic diagram of a solar water heater system. The solar heat collector 1 is installed on a roof or the like, and is circulated through an auxiliary tank 19 to a heat exchanger 11.
Communicate with The heat medium heated by the solar heat flows into the heat exchanger 11 in the hot water storage tank 9 by operating the circulation pump 12, and performs heat exchange with the water in the hot water storage tank 9.
Thereafter, the heat medium flows into the auxiliary tank 19 and is transferred to the solar heat collector 1 again. The path of the water heated by the heat medium is such that water is supplied from the water supply port 13 to the hot water storage tank 9 using the water supply pipe 14, and after the heating, the hot water supply pipe 15 is heated.
When the water cannot be sufficiently heated in rainy or winter season, the auxiliary heat source device 17 is used to heat the water to a desired temperature.

The operation of the solar water heater is controlled by a hot water storage tank 9.
When the detected temperature difference between the temperature detector 18a provided at the bottom of the solar cell and the temperature detector 18b provided inside the solar heat collector 1 becomes higher than a certain temperature, the circulation pump 12 is operated to generate heat. The heat collecting operation is performed by circulating the medium. If the detected temperature difference is less than a predetermined value, the circulation pump 12 is stopped to end the heat collecting operation.

[0007]

However, the conventional fin plate 4 as shown in FIG. 8 is adhered to the vertical tube 3 by brazing, and the fin plate 4 and the vertical tube 3 are formed of different metals. If so, the product life will be shortened due to electrolytic corrosion. In addition, the fin plate 4 and the vertical pipe 3
Even if they are formed of the same kind of metal, if the brazing is not performed reliably, the thermal efficiency will be significantly adversely affected, so that much time will be spent on the brazing operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a heat-absorbing tube and a solar heat collector provided with the heat-absorbing tube, which can reduce working time without causing electrolytic corrosion. The purpose is to provide.

[0009]

The present invention relates to the following. (1) An endothermic tube whose both ends are open and whose vertical section is square in the installed state. (2) An endothermic tube whose both ends are open and whose vertical cross section in the installed state has a shape in which the maximum length in the horizontal direction is longer than the maximum length in the vertical direction. (3) The endothermic tube according to the above (1) or (2), wherein both ends have a reduced tube diameter by drawing. (4) A solar heat collector provided with the heat absorbing tube according to any one of (1) to (3).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The heat absorbing tube used in the present invention has the functions of the vertical tube and the fin plate described in the prior art, and has a vertical cross section of square or maximum in the vertical direction when installed. The maximum horizontal length is longer than the length. FIG. 1 shows a longitudinal sectional view of an installed state of a heat absorbing tube of the present invention, in which (a) is specific example 1, (b) is specific example 2, (c) is specific example 3, (D) is specific example 4. The heat absorbing tube 25 shown in FIG. 1A has a substantially elliptical shape that is long in the horizontal direction, and the inside is a water passage. FIG.
The heat absorbing tube 25 shown in (b) has substantially flat upper and lower surfaces and arcs at both ends. The heat absorbing tube 25 shown in FIG. 1 (c) has a central portion of the heat absorbing tube 25 shown in FIG. 1 (a) with a swelling, and can increase the amount of water flow in the central portion of the tube. The heat absorption tube 25 shown in FIG. 1D has a bulge at the center of the heat absorption tube 25 shown in FIG. 1B, and can increase the amount of water passing through the center of the tube. FIG. 2 is a cross-sectional view showing a processing state of the heat absorbing tube of the present invention. The method for processing the heat absorbing tube 25 used in the present invention is not particularly limited, but specifically, it is preferable to deform the cross-sectional shape by crushing a cylindrical pipe from above and below with a press die. Further, it is preferable to reduce the diameter of both ends of the heat absorption tube 25 by drawing.

The material of the heat absorbing tube used in the present invention is not particularly limited, but a metal having high corrosion resistance and high heat conductivity to water or propylene glycol aqueous solution which is often used as a heat medium is used. Is preferred. Specifically, it is preferable to use copper, a copper alloy, stainless steel, or the like, and a thickness of 0.4 to 1.0 mm can be suitably used.

FIG. 3 is a simplified cross-sectional view showing the relationship between a heat absorbing tube and sunlight, (a) showing a heat absorbing tube having a circular cross section,
(B) shows the endothermic tube of the present invention. As shown in FIG. 3A, when a simple heat absorbing tube having a circular cross section is used, the heat absorbing tubes interfere with each other in the morning and evening when the solar altitude is low, and the efficiency is poor by intercepting the solar rays 20. As shown in FIG. 3B, by changing the cross-sectional shape of the heat absorption tube 25 from a circle, the heat absorption tube 25 does not intercept the sunlight 20 and is efficient.

The solar heat collector according to the present invention can use a conventionally used heat absorbing tube other than the conventionally used heat absorbing tube having the functions of the vertical tube and the fin plate. Both ends of the heat absorbing tube can be used. Are connected by a horizontal tube to form a heat collecting plate. The heat collecting plate is installed in a box via a heat insulating material, and the upper surface of the box is sealed with a transparent plate. The material of the horizontal tube is not particularly limited, but the same material as the heat absorbing tube can be suitably used. The material of the heat insulating material is not particularly limited as long as it has a heat insulating effect. Specifically, glass wool, rock wool, expanded styrene, expanded polyurethane, expanded polyethylene, and the like can be suitably used. . The material of the box is not particularly limited as long as it is rigid, but specifically,
An iron steel plate, an aluminum steel plate, FRP, or the like can be suitably used. The material of the transparent plate is not particularly limited as long as it transmits sunlight, and specifically, glass, polycarbonate, acrylic, or the like can be used.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a perspective view showing a manufacturing process of the heat absorbing tube according to the embodiment of the present invention. In this embodiment, a copper tube having a diameter of 80 mm with both ends opened is used, and the both ends are first drawn to a diameter of 15 mm by drawing. Further, the copper tube is press-worked except for the both ends which can be drawn, thereby obtaining the cross-sectional shape shown in FIG.
And

FIG. 5 is a perspective view showing a process of connecting the heat absorbing tube and the horizontal tube shown in FIG. Endothermic tube 25 has a diameter of 22 mm
Is connected to the horizontal pipe 2 by brazing or welding. FIG.
FIG. 2 is a partially cutaway perspective sectional view of the solar heat collector of the present invention. The box body 6 is made of FRP having a length of 1000 mm, a width of 1500 mm, and a height of 100 mm, and a heat insulating material 7 made of expanded styrene is laid on the bottom surface thereof. On the heat insulating material 7, a heat collecting plate 5 in which eight heat absorbing tubes 25 are connected to the horizontal tube 2 is placed.

FIG. 7 is a sectional view of the solar heat collector shown in FIG. An acrylic transparent plate 8 is placed on the top of the box 6 via a packing 24, and the transparent plate 8 is fixed to the box 6 by a holding bracket 22.

[0017]

According to the present invention, the cross-sectional shape of the heat absorbing tube in the installed state is a square or a shape in which the maximum length in the horizontal direction is longer than the maximum length in the vertical direction, thereby brazing the vertical tube and the fin plate. It is not necessary to carry out the operation, electric erosion does not occur, and the working time can be reduced.
Further, the solar heat collector using the heat absorbing tube of the present invention can efficiently absorb solar heat even when the solar altitude is low.

[Brief description of the drawings]

FIG. 1 shows a longitudinal sectional view of an installed state of a heat absorbing tube of the present invention, wherein (a) is a specific example 1, (b) is a specific example 2, (c) is a specific example 3, (D) is specific example 4.

FIG. 2 is a cross-sectional view showing a processing state of the heat absorbing tube of the present invention.

3A and 3B are simplified cross-sectional views showing the relationship between a heat absorbing tube and sunlight, wherein FIG. 3A shows a heat absorbing tube having a circular cross section, and FIG. 3B shows a heat absorbing tube of the present invention.

FIG. 4 is a perspective view showing a manufacturing process of the heat absorbing tube according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a step of connecting the heat absorbing tube and the horizontal tube shown in FIG.

FIG. 6 is a partially cut-away perspective sectional view of the solar heat collector of the present invention.

FIG. 7 is a cross-sectional view of the solar heat collector shown in FIG.

FIG. 8 shows a device built into a conventional solar heat collector.
(A) is a perspective view of the heat collecting plate, (b) is a partially exploded perspective view of the heat collecting plate, and (c) is a cross-sectional view of the horizontal tube.

FIG. 9 is an exploded perspective view showing a conventional solar heat collector.

FIG. 10 is a perspective view showing a conventional solar heat collector.

FIG. 11 is a system schematic diagram of a solar water heater.

[Explanation of symbols]

1. Solar heat collector 2. Horizontal pipe 3. Vertical pipe 4. Fin plate 5. Heat collecting plate 6. Box body 7. Insulation material 8. Transparent plate 9. Hot water storage tank 10. Circulation path 11. Heat exchanger 12. Circulation pump 13. Water inlet 14. Water supply pipe 15. Hot water supply pipe 16. Hot water supply port 17. Auxiliary heat source unit 18a. Temperature detector 18b. Temperature detector 19. Auxiliary tank 20. Sun rays 21. Heat collecting fins 22. Retainer bracket 23. Inlet / outlet joint 24. Packing 25. Endothermic tube

Claims (4)

[Claims] 1. An endothermic tube having both ends open and a square vertical cross section in an installed state. 2. An endothermic tube having both ends open and a vertical section in an installed state having a maximum horizontal length longer than a maximum vertical length. 3. The endothermic tube according to claim 1, wherein both ends are reduced in diameter by drawing. 4. A solar heat collector comprising the heat absorbing tube according to claim 1.