JPH08285378A - Vacuum type solar collector - Google Patents

Abstract

PURPOSE: To provide a vacuum type solar collector in which an increasing in weight is less in its amount during transportation or installing and temperature of water stored in a metallic water container is hardly influenced by the amount of solar radiation due to the fact that water acting as heat accumulating material is supplied into the metallic water container when the collector is installed at a roof or the like. CONSTITUTION: An outer circumference 18a of a metallic water container 18 is formed to be axially longer than that of an inner circumference 18b. Both ends of the outer circumference 18a are abutted against an inner circumferential surface of a metallic water container 13, supported and fixed there. In addition, one end 18c of the metallic water container 18 is formed with a plurality of water feeding holes 18c' (having a round shape and a diameter of 15mm) and further the other end 18d is formed with a plurality of air ventilation holes 18d' (having a round shape and a diameter of 3mm).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum type solar heat collector which can be installed on a roof or a roof and can heat water by solar heat. The present invention relates to a vacuum solar heat collector that is not affected by temperature and can always take out relatively hot water.

[0002]

2. Description of the Related Art In recent years, vacuum type solar heat collectors that utilize the thermal energy of sunlight as a heat source have been used in various industrial fields, and various forms thereof have been proposed.
For example, in Japanese Examined Patent Publication No. 3-56387, one end is sealed,
The other end is squeezed to a small diameter and opens, and a transparent long cylindrical glass container whose inside is held in vacuum, and one end is sealed,
The other end is narrowed to a small diameter and opened, and the whole is coaxially arranged inside the glass container via a support, has a volume of at least 60% or more of the inner volume of the glass container, and has a solar heat on its outer surface. Cylindrical metal water storage container coated with a selective energy absorption film, and a long first pipe inserted through the openings of the glass container and the metal water storage container to the vicinity of the sealed end of the metal water storage container. And a short second tube that penetrates through the opening of the glass container and is connected to the opening of the metal water storage container,
A vacuum solar heat collector including a sealing metal fitting for sealing the opening of a glass container has been proposed.

When such a vacuum solar heat collector is used, it is generally installed on the roof or the like so that the opening of the glass container is located above, and the opening of the metal water storage container is located above it. And an end of the first long tube is connected to an inlet header tube located above it. Then, water is supplied from the inlet-side header pipe through the long first pipe into the metal water storage container, and after warming by pumping for a certain time in the metal water storage container, water is newly supplied from the long first pipe. Is supplied to the metal water storage container to discharge the warm water in the metal water storage container from the gap between the long first pipe and the short second pipe, and push it up to the outlet-side header pipe to take it out to the outside. To be

By the way, since the heat source of the solar heat collector is the heat energy of the sun's rays, the amount of heat of the heat medium such as water greatly depends on the amount of solar radiation. After that, the heat cannot be collected at all.

The vacuum type solar heat collector as described above has less convective heat loss and conduction heat loss than the flat plate type solar water heater and is excellent in heat collecting efficiency. Therefore, when the weather is good,
The water pumped in the metal water container becomes considerably hot, but once the weather becomes bad or after sunset, the water temperature drops significantly.

Under these circumstances, the applicant of the present invention has disclosed in Japanese Utility Model Laid-Open No. 6-64070 that a large number of heat medium flow passages are provided inside the metal water storage container of the vacuum solar heat collector having the above-described configuration. It is proposed to arrange the heat storage material as it is formed.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Actual Kaihei 6-64070
In the case of the vacuum-type solar heat collector disclosed in No. ₂ , the sensible heat storage material such as water, stone, gravel, concrete, brick, glass powder, soil, iron powder, Zn (NO ₃ ) ₂ , 2H is used as the heat storage material.
_{2 O, Ca (NO 3)} 2 · 4H 2 O, NaHPO 4 · 1
A latent heat storage material such as 2H ₂ O or a reaction heat storage material that utilizes reaction heat such as sodium sulfide or magnesium chloride is used. Further, among these heat storage materials, those which are mixed or react with the heat medium in the metal water storage container are put in a capsule or a container so that the mixture or reaction with the heat medium does not occur.

However, in the case of such a vacuum solar heat collector, whichever heat storage material is used, it is necessary to put the heat storage material in the metal water storage container in advance, so that the weight is significantly increased. This increases the workability when transporting or installing on the roof.

The present invention has been made in view of the above circumstances, and after installing on a roof or the like, water that acts as a heat storage material is supplied into a metal water storage container, so that the weight during transportation and installation is reduced. It is an object of the present invention to provide a vacuum solar heat collector in which the increase in temperature is small and the temperature of water in a metal water storage container is less likely to be affected by the amount of solar radiation.

[0010]

The vacuum solar heat collector of the present invention has a transparent long cylindrical shape in which one end is sealed, the other end is narrowed to a small diameter and opened, and the inside is held in vacuum. Of the glass container, one end of which is hermetically sealed, the other end of which is narrowed to a small diameter to open, and the whole of which is coaxially arranged inside the glass container via a support and occupies 60% or more of the inner volume of the glass container. A cylindrical metal water storage container having an inner volume and having an outer surface coated with a selective absorption film, and the vicinity of a sealed end inside the metal water storage container penetrating through the openings of the glass container and the metal water storage container. A long first tube inserted into the glass container, a short second pipe penetrating the opening of the glass container and connected to the opening of the metal water storage container, and a sealing metal fitting for sealing the opening of the glass container It is made up of a vacuum type thicker that is installed and used so that the opening of the glass container is located above. In the heat collector, a metal water storage container is supported and fixed between the metal water storage container and the long first pipe, and water supply has a size such that water smoothly flows into the lower end portion of the metal water storage container. A hole is formed, and an air vent hole having a size that makes it difficult for water to flow out is formed at an upper end portion.

Further, in the vacuum solar heat collector of the present invention, the opening area of the water supply hole of the metal water container is 50 to 400 mm ^2.
And the opening area of the air vent hole is 1 to 25 mm ² . That is, the opening area of the water supply hole is 5
If it is less than 0 mm ² , it will be difficult for water to flow in smoothly,
If it is larger than 400 mm ² , it is not preferable because the manufacturing restriction becomes large and convection of water easily occurs inside and outside the metal water container. Also, the opening area of the air vent hole is
If it is less than 1 mm ² , it will be difficult to remove air,
If it is larger than 25 mm ² , the outflow amount of water increases, which is not preferable.

Further, regarding the size of the metal water storage container according to the present invention, in consideration of the heat storage effect and the effective amount of hot water taken, the metal water storage container has an inner volume which occupies 30 to 80% of the volume of the metal water storage container, and is made of metal. It is desirable to be arranged coaxially around the entire circumference between the water reservoir and the elongated first tube. Further, the water supply hole and the air vent hole formed at both ends of the metal water retention container have the sizes as described above in order to obtain a desired effect, but these holes are not limited to one location, but a plurality of locations. It may be provided in.

In order to support and fix the metal water storage container between the metal water storage container and the long first pipe, a part of the metal water storage container abuts on the inner peripheral surface of the metal water storage container. It may be formed or a support may be provided between the metal water storage container and the metal water storage container.

[0014]

When the vacuum solar heat collector of the present invention is used,
It is necessary to install the heat collector on the roof so that the opening of the glass container is located above. Then, when water flows into the metallic water storage container from the long first pipe, the water also flows into the metallic water storage container through the water supply hole formed at the lower end of the metallic water storage container. The air existing in the air will escape to the outside through the air vent hole formed in the upper end portion.

After warming the water filled in the metallic water storage container and the metallic water storage container in this way with solar heat,
When new water is supplied into the metallic water storage container from the long first pipe, the hot water in the metallic water storage container is discharged from the vacuum solar heat collector through the gap between the long first pipe and the short second pipe. However, the hot water in the metal water container is difficult to flow out from the air vent hole, and most of it remains as it is.

Therefore, the metal water container is always filled with hot water, which acts as a heat storage material. That is, the heat stored in the hot water in the metal water container is transferred to the water newly flowing into the metal water container and has the effect of warming it, and as a result, even when the amount of solar radiation is small The water supplied to the water storage container easily warms up, and the temperature of the water does not drop significantly.

[0017]

The vacuum solar heat collector of the present invention will be described in detail below with reference to examples.

FIG. 1 is a vertical sectional view of the vacuum solar heat collector of the present invention.

In the figure, a vacuum solar heat collector 10 has a transparent long cylindrical glass container 11 whose one end is hermetically sealed, the other end is narrowed to a small aperture and opened, and the inside of which is held in vacuum. , One end is sealed, the other end is narrowed to a small diameter and opened, and the whole is coaxially arranged inside the glass container 11 via the support tools 12, 12, and 60% or more of the internal volume of the glass container 11 is A cylindrical metal water storage container 13 having an internal volume that occupies and having an outer surface coated with a selective absorption film (not shown);
A long first tube 14 penetrating through the openings of the glass container 11 and the metal water storage container 13 and inserted to the vicinity of the sealed end of the metal water storage container 13 and the metal storage water penetrating through the opening of the glass container 11. A short second pipe 15 connected to the opening of the container 13, a glass sealing metal fitting 16 and an intermediate joint sealing metal 17 for sealing the opening of the glass container 11, and a metal water storage container 13
And a metal water container 18 arranged coaxially over the entire circumference between the long first pipe 14.

The metal water retention container 18 has an outer peripheral portion 18a, an inner peripheral portion 18b, and end portions 18c connecting both end portions thereof,
It is composed of 18d. The outer peripheral portion 18a of the metallic water retaining container 18 is formed to be longer in the axial direction than the inner peripheral portion 18b, and both ends of the outer peripheral portion 18a are in contact with the inner peripheral surface of the metallic water storage container 13. It is supported and fixed by. Further, one end 1 of the metal water retention container 18
8c has a plurality of water supply holes 18c '(round shape, diameter 15
mm) and a plurality of air vent holes 18d '(round shape, diameter 3 mm) are formed at the other end 18d. Further, a plurality of water passage holes 18a 'are formed at both ends of the outer peripheral portion 18a of the metal water retention container 18.
These water passage holes 18a 'have an opening area equal to or larger than that of the water supply holes 18c', and the peripheral portion of the metal water storage container 13 is also filled with water through them. .

One end of the long first pipe 14 is connected to the inlet side header pipe 19 by welding, and one end of the short second pipe 15 is welded to the small diameter opening of the metal water storage container 13. The other end of the short second pipe 15 is connected to the outlet side header pipe 20 by welding.

The glass container 11 is manufactured by welding the ends of two glass caps formed in a predetermined shape to a glass tube constituting the outer shell member of the vacuum solar heat collector 10. At the center of one glass cap,
An exhaust pipe 11a is formed. The exhaust pipe 11a is evacuated from the glass container 11 and evacuated to, for example, 1 × 10 ⁻⁴ Torr or less and then closed, and a rubber cap 21 is fitted on the exhaust pipe 11a. . An opening is formed in the center of the other glass cap, and one end of the glass sealing metal fitting 16 is attached to the opening. Glass sealing metal fitting 1
6 is a cylindrical shape and is made of a material that can be well sealed with the glass container 11. For example, when the glass container 11 is soda lime glass, 42% Ni-6% Cr steel, and in the case of borosilicate glass, Kovar alloy. Made from.

At the other end of the glass sealing metal fitting 16, one end of a cylindrical intermediate joint sealing metal fitting 17 is attached by welding so as to cover the outer periphery thereof, and the other end of the intermediate joint sealing metal fitting 17 has a short second end. It is welded to the pipe 15. The intermediate sealing member 17 is made of the same metal as the short second pipe 15 or a metal having a substantially same coefficient of thermal expansion and excellent corrosion resistance.

The metal water storage container 13 is made of stainless steel, copper,
After processing the metal plate made of iron etc. into a cylindrical shape and forming the outer peripheral part by welding the joint part, from the metal having the same or the same thermal expansion coefficient as the outer peripheral part at both end openings It is manufactured by welding and sealing the sealing cap.

The metal water container 18 is also made of stainless steel, copper,
A metal water storage container 13 formed of a metal plate made of iron or the like
It has an internal volume that occupies 30 to 80% of the internal volume.
In the case of producing this, first, a metal plate is processed into a cylindrical shape, and the joint portion is welded to form the outer peripheral portion 18a and the inner peripheral portion 18b. Next, a method is employed in which ends 18c and 18d made of a metal plate provided with a plurality of water supply holes 18c 'and air vent holes 18d' are welded and sealed to both ends thereof.

When such a vacuum solar heat collector 10 is used, it is connected to the inlet side header pipe 19 and the outlet side header pipe 20 so that the opening of the glass container 11 is located above.

By supplying water from the long first pipe 14 into the metallic water storage container 13 through the inlet-side header pipe 19, the metallic water storage container 13 and the metallic water storage container 18 are filled with water. After that, heat the water with the heat energy of the sun's rays. When water is supplied into the metallic water storage container 13, the air existing in the metallic water storage container 18 is discharged through the air vent hole 18d '.

After that, water is newly added to the header pipe 19 on the inlet side.
When the water is supplied from the long first pipe 14 into the metal water storage container 13 through the hot water, the warm water in the metal water storage container 13 is discharged from the gap between the long first pipe 14 and the short second pipe 15 to the outlet side header pipe 20. However, since the opening area of the air vent 18d 'is small, the hot water in the metal water container 18 is difficult to flow out from here, and most of it remains as it is. As a result, for the newly supplied water, the metal water retention container 1
Since the heat of the hot water remaining inside 8 is transmitted, it is easy to warm up, and the decrease in water temperature can be suppressed even after bad weather or after sunset.

[0029]

As described above, in the vacuum solar heat collector of the present invention, the metal water storage container is arranged in the metal water storage container, and the water once supplied to the metal water storage container flows out. It is difficult to do this, and when this water is heated, it works as a heat storage material, so it is difficult for the temperature of the water in the metal water storage container to be affected by changes in the amount of solar radiation.

Moreover, the vacuum solar heat collector of the present invention supplies water into the metal water container after it is installed on the roof or the like, so that the weight during transportation and installation is small.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a vacuum solar heat collector of the present invention.

[Explanation of symbols]

 10 Vacuum Solar Heat Collector 11 Glass Container 12 Support Tool 13 Metal Water Storage Container 14 Long First Tube 15 Short Second Tube 18 Metal Water Retaining Container 18c 'Water Supply Hole 18d' Air Venting Hole 19 Inlet Header Tube 20 Outlet Side header tube

Claims (2)

[Claims] 1. A transparent long cylindrical glass container, one end of which is sealed and the other end of which is narrowed and opened to a small diameter, and the inside of which is held in a vacuum, and one end of which is sealed and the other end of which is a small diameter. The entire inner surface of the glass container is coaxially arranged via a support and has an inner volume occupying 60% or more of the inner volume of the glass container, and the outer surface thereof is coated with a selective absorption film. The formed cylindrical metal water storage container, the glass container and the long first tube penetrating through the opening of the metal water storage container to the vicinity of the sealed end in the metal water storage container, and the opening of the glass container It consists of a short second pipe that penetrates through the section and is connected to the opening of the metal water storage container, and a sealing metal fitting that seals the opening of the glass container so that the opening of the glass container is located above. In the vacuum type solar collector to be installed and used, the metal water reservoir and the long first A water retention container made of metal is supported and fixed between the pipe and the water retention hole at the lower end of the water retention container made of metal, the size of which allows smooth inflow of water, and water does not easily flow out at the upper end. A vacuum solar heat collector, characterized in that it is formed with an air vent hole having a size. 2. The opening area of the water supply hole of the metal water container is
50 to 400 mm ² and the opening area of the air vent hole is
It is 1-25 mm < ² >, The vacuum type solar heat collector of Claim 1 characterized by the above-mentioned.