JPH0664070U - Vacuum solar collector - Google Patents

Abstract

(57) [Abstract] [Purpose] Since the heat storage material is placed in the metal container, the temperature of the heat medium in the metal container is not easily influenced by the amount of solar radiation, and the heat stored in the heat storage material is It is an object of the present invention to provide a vacuum solar heat collector that can efficiently take out a relatively high-temperature heat medium for a long time even if the amount of solar radiation is small, because the heat can be efficiently transmitted to the heat medium. [Structure] Each crushed stone 20 has a size larger than the opening of the long first pipe 14 and the gap between the long pipe 14 and the short second pipe 15 so as not to come out of the metal container 13, A large number of gaps are formed between the crushed stones 20, and these gaps serve as heat medium flow passages.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vacuum solar heat collector which can always take out a relatively high-temperature heat medium without the temperature of the heat medium being largely affected by the amount of solar radiation.

[0002]

[Prior art]

 In recent years, vacuum type solar heat collectors that use 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, Japanese Patent Publication No. 3-56387. Is sealed, the other end is squeezed to a small diameter and opened, and a transparent long cylindrical glass container whose inside is held in vacuum, and one end is sealed and the other end is squeezed to a small diameter. The glass container is opened and is coaxially arranged inside the glass container via a support, and has a volume of at least 60% or more of the internal volume of the glass container. The outer surface of the glass container is covered with a selective absorption film for solar thermal energy. The formed cylindrical metal container, the glass container and the long first tube penetrating the opening of the metal container to the vicinity of the sealed end in the metal container, and the opening of the glass container. Pierced and connected to the opening of the metal container There a second tube, Bei a sealing fitting which seals the opening of the glass container Ete made vacuum solar heat collector has been proposed.

When such a vacuum solar heat collector is used, it is generally arranged such that the opening of the glass container is on the upper side, and the opening of the metal container is on the outlet side header pipe located above it. And one end of the long first tube to the inlet header tube located above it. Then, a heat medium such as water or air is supplied from the inlet-side header pipe through the long first pipe into the metal container, and the medium is left in the metal container for a certain period of time to be warmed, and then the longer first pipe. By newly supplying the heat medium into the metal container from, the heat medium in the metal container is discharged from the gap between the long first pipe and the short second pipe and pushed up to the outlet side header pipe. The method of taking it out is adopted.

By the way, as described above, 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 is greatly influenced by the amount of solar radiation, and when the weather is bad, it hardly collects heat. After sunset, the heat cannot be collected at all.

The vacuum solar heat collector as described above has less convective heat loss and conduction heat loss than the flat plate solar water heater and has excellent heat collection efficiency. Therefore, when the weather is good, the inside of the water storage container The temperature of the heat transfer medium is quite high, but once the weather becomes bad or after sunset, the temperature drops significantly. Especially when the heat medium is air, the temperature of the heat medium in the metal container greatly depends on the amount of solar radiation because it is more significantly affected.

Under these circumstances, in Japanese Utility Model Laid-Open No. 58-46050, a large-diameter transparent glass outer tube and a small-diameter transparent glass inner tube are arranged coaxially, and the transparent glass outer tube and the transparent glass are The tube ends of the lath inner tube or the tube ends are fusion-sealed to form a closed space between the transparent glass outer tube and the transparent glass inner tube, and the closed space is kept in a vacuum state. A heat transfer medium tube is arranged inside the glass inner tube through a heat storage material, and a seal member is arranged at the fusion-sealed portion of the transparent glass outer tube and the transparent glass inner tube at the tube ends. A heavy glass tube collector is disclosed. According to this collector, thermal energy is temporarily stored in a heat storage material and then transferred to the heat medium, so that the temperature change of the heat medium due to the amount of solar radiation becomes small.

[0007]

[Problems to be solved by the device]

 However, in the collector as disclosed in Japanese Utility Model Laid-Open No. 58-46050, since the heat medium flows only in the heat medium pipe, the heat transfer area of the heat storage material to the heat medium is small, and the heat stored in the heat storage material is efficiently stored. Does not reach the heat carrier.

The present invention has been made in view of the above circumstances. Since the heat storage material is arranged in the metal container, the temperature of the heat medium in the metal container is not easily influenced by the amount of solar radiation, and the heat storage is Since the heat stored in the material is efficiently transmitted to the heat medium, even if the amount of solar radiation is small, it is possible to take out the heat medium of a relatively high temperature over a long period of time. It is intended to provide.

[0009]

[Means for Solving the Problems]

 The vacuum solar heat collector of the present invention has one end sealed with a transparent long cylindrical glass container whose one end is sealed and the other end is squeezed to a small diameter to hold the inside in vacuum. Now, the other end is narrowed to a small diameter and opened, and the whole is coaxially arranged inside the glass container via a support, and has a volume occupying at least 60% or more of the inner volume of the glass container, A cylindrical metal container whose outer surface is coated with a selective absorption film and a long first container inserted through the glass container and the opening of the metal container to the vicinity of the sealed end in the water storage container. A vacuum solar heat collector comprising a tube, a short second tube penetrating the opening of the glass container and connected to the opening of the metal container, and a sealing metal fitting for sealing the opening of the glass container. In the heat generator, the heat storage material is arranged so that many heat medium flow passages are formed in the metal container. It is characterized by comprising.

Examples of the heat storage material used in the present invention include sensible heat storage materials such as water, stone, gravel, concrete, leng, glass powder, soil, iron powder, Zn (NO ₃ ) ₂ .2H ₂ O, Ca _{(NO 3) 2 · 4H 2} O, NaHPO 4 · 12H 2 O , etc. latent heat storage material, sulfide sodium, reaction heat thermal storage material utilizing the heat of reaction such as magnesium chloride are suitable.

However, among the heat storage materials, those that are mixed or react with the heat medium in the metal container must be placed in a capsule or a container so that the mixture or reaction with the heat medium does not occur. .

Further, the heat storage material, the capsule and the container in which the heat storage material is put, the opening portion of the first pipe whose length is long and the opening portion of the gap between this pipe and the second pipe which is short so that they do not come out of the metal container. They may need to be larger, or reticulates attached to these openings.

[0013]

In the vacuum solar heat collector of the present invention, the heat storage material is arranged so that a large number of heat medium flow passages are formed inside the metal container, so that the vacuum solar heat collector is collected in the metal container. The amount of heat is stored in the heat storage material in addition to the heat medium, and the heat transfer area of the heat storage material with respect to the heat medium is large, and the heat stored in the heat storage material is efficiently transmitted to the heat medium, resulting in less solar radiation. However, it becomes possible to take out the heat medium having a relatively high temperature over a long period of time.

[0014]

【Example】

 Hereinafter, the vacuum solar heat collector of the present invention will be described in detail based on embodiments.

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

In the figure, a vacuum solar heat collector 10 includes a transparent long cylindrical glass container 11 having one end sealed and the other end narrowed to a small diameter to open, and the inside of which is kept 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 through the support tool 12 and occupies 60% or more of the inner volume of the glass container 11. And a cylindrical metal container 13 having a selective absorption film (not shown) formed on the outer surface thereof and the glass container 11 and the opening of the metal container 13 to penetrate the metal container 13 A long first tube 14 inserted near the sealed end of the glass container 11, a short second tube 15 penetrating the opening of the glass container 11 and connected to the opening of the metal container 13, and an opening of the glass container. A glass sealing metal fitting 16 for sealing the parts and a middle joint sealing metal fitting 17 are provided. Become.

One end of the long first pipe 14 is connected to the inlet-side header pipe 18 by welding, and one end of the short second pipe 15 is welded to the small diameter opening of the metal container 13. The other end of the pipe 15 is connected to the outlet side header pipe 19 by welding.

The metal container 13 is filled with a large number of crushed stones 20 as a heat storage material. Each crushed stone 20 has a size larger than the opening of the long first pipe 14 and the gap between this pipe 14 and the short second pipe 15 so as not to come out of the metal container 13. A large number of gaps are formed between 20, and these gaps serve as heat medium flow passages.

The glass container 11 is manufactured by welding the ends of two glass caps formed in a predetermined shape in advance to a glass tube that constitutes an outer shell member of the vacuum solar heat collector 10. . An exhaust pipe 11a is formed in the center of one of the glass caps, and the exhaust pipe 11a is closed after exhausting the inside of the glass container 11 to a vacuum of, for example, 1 × 10 ^-4 Torr or less. A rubber cap 21 is fitted on the top. 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. The glass sealing metal fitting 16 has a cylindrical shape and is made of a material which 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, borosilicate glass Are made from Kovar alloy.

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 of the glass sealing metal fitting 16. The other end of the intermediate joint sealing metal fitting 17 has a short first end. It is welded and connected to the second 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 thermal expansion coefficient and excellent corrosion resistance.

The metal container 13 is formed by processing a metal plate made of stainless steel, copper, iron, or the like into a cylindrical shape, and welding the joints thereof to form a side body portion, and then forming a side body portion at both end openings thereof. It is manufactured by welding and sealing a sealing cap made of the same metal as the part or a metal having a similar thermal expansion coefficient.

When the vacuum type solar heat collector 10 is used in good weather when air is used as a heat medium, the air in the metal container 13 and the crushed stone 20 are warmed by the thermal energy of the sun's rays. Then, when air is newly sent into the metal container 13 from the long first pipe 14, the air in the metal container 13 passes through the gap between the crushed stones 20 and is taken out of the metal container 13. According to such a vacuum solar heat collector 10, the temperature of the air in the metal container 13 is less likely to drop because the weather is bad and the crushed stones 20 store heat even after sunset.

Example 2 FIG. 2 is also a vertical cross-sectional view of the vacuum solar heat collector of the present invention, and FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG.

The structure of this vacuum solar heat collector 22 is the same as that of the sky solar heat collector 10 of FIG. 1 except for the structure of the metal container 23.

That is, the metal container 23 of the vacuum solar heat collector 22 is supported in the glass container 24 by the support 25, but the crushed stone 20 does not exist therein, and instead the heat storage material is used. An enclosure 26 is arranged. The heat storage material enclosure 26 is made of stainless steel or the like, and NaHPO ₄ .12H ₂ O is enclosed therein as a heat storage material. The heat storage material enclosing container 26 has a cylindrical shape whose outer diameter is substantially the same as the inner diameter of the metal container 23, and a hole 26a through which a long first pipe 27 is penetrated is formed in the central portion in the longitudinal direction. In addition to the holes 26a, a plurality of small holes 26b serving as heat medium flow passages are formed.

When such a vacuum solar heat collector 22 is used in good weather when air is used as the heat medium, the heat energy of the sun's rays causes the air in the metal container 23 and the NaHPO in the heat storage material enclosure container 26 to change. ₄・ 12H ₂ O is heated. After that, when air is newly sent into the metal container 23 through the long first pipe 27, the air in the metal container 23 passes through the plurality of small holes 26 b of the heat storage material enclosing container 26 and the metal container 23. Be taken out of the. According to such a vacuum solar heat collector 22, the temperature of the air in the metal container 23 decreases because the weather is bad and the heat of NaHPO ₄ .12H ₂ O is stored even after sunset. hard.

Comparative Example A vacuum type solar heat collector having the same structure except that the crushed stone 20 was not placed in the metal container 13 of the vacuum type solar heat collector 10 of Example 1 was manufactured.

The relationship between the temperature of the air taken out from each of the vacuum solar heat collectors of Examples 1 and 2 and the comparative example produced as described above and the amount of solar radiation is shown in the graph of FIG.

As is apparent from FIG. 4, the air taken out from the vacuum solar heat collector of the comparative example was easily affected by the amount of solar radiation, and the temperature changed drastically with time. The air taken out from each of the vacuum solar heat collectors in 1 above was not affected by the amount of solar radiation and was always at a relatively high temperature.

[0030]

[Effect of device]

 As described above, in the vacuum solar heat collector of the present invention, since the heat storage material is arranged so that a large number of heat medium flow passages are formed inside the metal container, the vacuum solar heat collector can be collected in the metal container. In addition to the heat medium, the heat is also stored in the heat storage material, and since the heat transfer area of the heat storage material with respect to the heat medium is large, the heat of the heat storage material is efficiently transferred to the heat medium, so even if the amount of solar radiation becomes small, It is possible to take out the heat medium having a relatively high temperature over a long period of time.

[Brief description of drawings]

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

FIG. 2 is a vertical cross-sectional view of the vacuum solar heat collector of the present invention.

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a graph showing the relationship between the temperature of air taken out from each vacuum solar collector and the amount of solar radiation.

[Explanation of symbols]

 10, 22 Vacuum type solar heat collector 11, 24 Glass container 13, 23 Metal container 14, 27 Long first tube 20 Crushed stone 26 Heat storage material sealed container

Claims (1)

[Scope of utility model registration request] 1. A transparent long cylindrical glass container having one end hermetically sealed, the other end squeezed to a small diameter and opened, and the inside kept vacuum, and one end hermetically sealed and the other end small caliber. 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 container, the glass container and the long first tube inserted through the opening of the metal container to the vicinity of the sealed end in the metal container, and the opening of the glass container In a vacuum solar heat collector comprising a short second tube connected to the opening of the metal container and a metal fitting for sealing the opening of the glass container, The heat storage material is arranged so that a plurality of heat medium flow passages are formed. Vacuum type solar heat collector.