JPS6032092B2 - Symmetrical tubular solar energy collector with circular cross section - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a symmetrical tubular solar energy collector with a circular cross section.

More specifically, ``the present invention provides a relatively inexpensive and effective unit for installation as a module or unit in a solar energy converter system. It is made from glass of known tube manufacturing methods, such as those currently prevalent in the manufacture of glass tube products.

The tubular glass solar energy collector is assembled to the manifold such that the tubular collector is removably coupled to the manifold.

The manifold may be configured to have collectors disposed on either side thereof and extend laterally in rows along the manifold to provide coupled energy collection systems for cooling or heating. One of the important objects of the invention is to provide a collector unit with low manufacturing and operating costs.

The collector unit is made mostly of glass.
It can be mass-produced from relatively inexpensive raw materials and is easy to use and replace. Another important feature of the invention is the construction of the collector in which the three coaxial tubes are made of glass.

The two outer tubes consist of glass tubes that resemble enlarged test tubes with one end closed.

The outer tube is sealed to the intermediate inner tube such that the space therebetween is depressurized to the extent practical and effective to prevent heat loss through convection and conduction. The intermediate inner tube is covered with a highly absorbent, low specular, energy absorbing cladding. A third tube is arranged inside the intermediate tube and is adapted to convey the fluid medium to the upper end of the interior of the intermediate tube. Each of the parts described above consists of the same or similar glass composition, apart from the cladding.
Their thermal expansivity is similar to that of the glass-to-metal gradient used outside conventional types of collectors.
) allows glass-to-glass frame seals rather than seals, thus avoiding damage due to differential thermal expansion during operation.
Additionally, the glass sections are easily sealed together and are inexpensive to manufacture. Another object of the invention is to provide a manifold for fluidized media to and from a plurality of collector units coupled to the manifold, the collector units being quickly removable into sockets in the manifold for each collector unit. ○Has a ring seal. Another object of the invention is that spring support means mounted to the inner end of the inner tube of the coated intermediate absorber tube hold that end of the absorber tube in a coaxial position within the outer tube, such that the pond end of the absorber tube is Ensure that it is sealed to the outer tube wall for support.

The present invention will now be described in more detail with reference to the accompanying drawings. FIG. 1 shows a typical use of the invention.

A house 10 has a number of modules 12 of the solar energy converter of the invention with its roof 11 located closest to the sun. The area covered by module 12 will be selected by one skilled in the art to provide cooling or heating of the residence. The modules of the solar energy converter are shown in detail in FIG.

Module 12, shown in partially exploded view, includes a central manifold section 13 extending downwardly from the roof section (FIG. 1). Extending outwardly from both sides of the manifold 13 are a plurality of collector units 1, which will be further described.
It is 4. The collector 14 is plug-connected to side ports 15 spaced apart along opposing vertical side walls 16, 17 of the manifold 13. Manifold 1
Inside 3 are longitudinal passages 18, 19 extending along the entrance 15 on either side of the manifold. Aisle 18 and 1
9 there is a central passageway 20 defined by internal longitudinal walls 21 and 22. There are a plurality of spaced apart entrances 23 along the walls 21,22. The openings 15 and 23 are a pair having the same axis. Manifold 13 is connected to a fluid handling system represented by a duct 24 having an upper conduit passage 25 and a lower conduit passage 26 .
The duct 24 is connected to the heating system or the cooling system (third
The solar energy converter module 12 extends between the fluid heat exchanger (shown as E in the figure) and the solar energy converter module 12 . aisle 2
5 conveys a relatively cold fluid medium, such as water or air, and transfers the medium to the combination entrance connection 39 of the vertical wall 24a of the duct 24 and the vertical end wall 28 of the manifold 13.
It will be introduced through the opening □27. The entrance 27 communicates with the central passage 20 of the manifold 13. The duct 24 and the manifold 13 are connected and sealed together by a gasketed face 29 held by a cap screw 301 which threadably engages the end wall 28 at the location indicated by the reference numeral. Gasket 29 may be any suitable compressible gasket material that can withstand use at elevated temperatures. Sewn lower closures 32, 33 in wall 24a and combined lower openings 34, 35 in wall 28 allow each passage 18, 19 to communicate with passage 26 of the duct for conveying the heated fluid medium coming from collector 14. Manifold 13 is surrounded by a top wall 36, a bottom wall 37, and a vertical wall 38 at the outer end.

Each collector 14 shown in FIGS. 2 and 3 is all of similar construction and each has an outer glass tube 40 of a suitable length, e.g., 4 to 7 feet, and a standard diameter. , for example, an outer diameter of 2 inches.

The lower mirror surface 45 may be used to reflect the specular energy into a portion of the absorption tube 41 of the collector. The inner tube 41 is made of glass and is somewhat smaller in diameter and slightly larger in length. The tube 41 is pre-coated on its inner surface with a highly absorbent, low radiation energy absorbing coating material 42. Examples of such wavelength selective coatings are:
A basecoat of metal, such as aluminum or silver, deposited on a glass surface, with a further semiconductor-type coating applied to the metal surface coating to provide the desired wavelength selectivity. The high performance wavelength selective coating preferably has a wavelength of 0.
It has an absorption of 8 or more and an infrared radiation of 0.1 or less. Inside the tube 41 is a glass fluid conveying tube 43 for carrying a relatively cool fluid medium.
It is designed to be conveyed into the collector inside the tube 41 near its closing wall 41a.

The inner end 43a of the conveying pipe 43 is open (FIG. 2).
As an assembly, the absorption tube 41 already externally coated with a wavelength-selective coating 42 is further provided with a snap-on end support cap 46 (FIG. 5) which provides an inner end support means for the tube 41 within the tube 40. ing.

The cap 46 has a hemispherical shell and multiple (3 or 4)
It has legs 47. The cap 46 is made of metal or plastic with some elasticity so that it is fitted onto the inner end of the tube 41. A tube 41 is inserted into the outer tube 40 and, in a first embodiment of the invention, connects the connection 40a.
It is secured to the outer tube 40 by melting the open end of the outer tube to the tube 41 (FIG. 2). Thereafter, vacuum treatment is performed from the opposite side of the tube 40, and the chip 40 is
8, the seal space 49 obtained between the outer tube 40 and the absorption tube 41 is highly evacuated (10-4).
) The transport tube is then inserted inside the absorption tube 41. Each of the collector units 14 is installed in the manifold 13 in the following manner.

The free end 43b of the conveying tube 43 is connected to the inner wall 20 of the manifold,
It has an outer diameter that is approximately the same as the diameter of the gate 23 of No. 21. A rubber o-ring 50 is provided at the free end 43b of the transfer tube to seal it to the opening 23. Similarly, the free end 41b of the absorption tube
It has an outer diameter that is approximately the same as the dimension of the opening 15 of No. 7. A rubber o-ring 51 is provided at the free end 41b of the absorption tube to seal the absorption tube to the entrance 15. Opening 15
and 23 have concave grooves 51a and 50a, respectively, to receive gasket rings 51 and 50.
The collector structures shown in FIGS. 7 and 8 are designated by corresponding reference numerals with prime signs for like parts.

Further, as can be seen from FIG. 7 or from FIG. 8, which is a more detailed view, the hollow elongated tubular glass absorption tube members 41, 41'
The open end of the outer tube 40' is flared outwardly, and the flared end is fused to an annular glass portion adjacent and surrounding the open end of the outer tube 40', thus Tubular glass absorption tube members 41, 41' and the outer tube 40
′ is sealed.

The collector 14' has a clear glass outer tube 40' which is closed at one outer end with a sealed tube section 48'.

The other end of tube 40' is open. The inner tube 41' consists of a glass tube of somewhat smaller diameter and shorter length.
The inner glass tube 41' is precoated on its outer surface along most of its length with a highly absorbing, low specular, wavelength selective coating 42' as described above in the first embodiment. ing. Before the coating 42' is applied, the open end of the glass tube 41' is preferably provided with an outwardly directed open end in the shape of a divergent end 60 shown in FIGS. 7 and 8. A coating 42' is applied over the tube from near the divergent end 60 to the closed end of the tube 41'. The tube 41' is then inserted into the glass outer tube 40', with a simple coil spring 61 first inserted into the closed end of the tube 41' and attached to the inner closed end of the tube 40'. Make sure they touch each other. At this stage of assembly, the tube is still open at the position indicated by reference numeral 48'. tube 40'
and 41' in the position shown in FIG. 7, with spring 61 under some compression, and the divergent end 60 of tube 41' and
The open end of tube 40' is heated so that the glass melts together and forms two tubes 40' and 41 as shown in FIG.
An integral end connection is formed with . Later, the outer tube 40
' Exhaust from the opposite pipe indicated by reference numeral 48' and seal with tip 48' as shown to connect the outer tube 4.
The space 49' between the tube 41' and the inner tube 41' is reduced to a vacuum, preferably on the order of 10-1 mel or more.
The dressing 42' is thus in the vacuum of the space 49'. The conveying pipe 43' is connected to the entrance 15' or 23' on one side or the other side of the manifold 13, as described above.
is inserted through the annular rubber grommet 63 and wall village 62. The rubber o-ring 51 is seated in the groove 51a of the stop 15' and is compressed against the outer wall surface of the pipe 40' near the stop of the collector. O-ring 51 forms the main seal for collector 14' at the manifold entrance.

The manifold 13 has a foamed insulation layer 64 around its externally exposed surface, which insulator layer has a molded entrance 65' aligned with the entrance of the manifold at a location corresponding to the collector opening of the manifold.

A thin washer-like seal 66' made of flexible material is opened □6
embedded in the insulator at each of 5' and closed at 65
' is annularly engaged around the circumference of tube 40' to provide an external seal at the entrance. The outer tube 40' is made of highly conductive, preferably low iron, transparent glass.

Inner absorption tube 41' is preferably substantially comprised of glass of the same composition as tube 40' to facilitate bonding and to provide a fused seal between the inner and outer tubes near their junctions. To reduce the residual stress in glass tube 4
Regarding the wavelength selective coating layer 42' to 1', the coating comprises:
It consists of a material with an absorptivity of 0.80 or more and a sub-coating material with a specular emissivity of 0.1 or less.

For high absorption as indicated, metal compounds such as oxides or sulfides of chromium, nickel, knots, etc. can be used with good results. In some cases, combinations of metals and their compounds are the best for absorbing solar energy. As shown for low heat sinks, aluminum, silver, copper and gold are preferred as secondary coatings, on which the superabsorbent coating material is applied. The method of depositing the coating material selected must be such as to give a tunable thin film.

Such methods that have been successfully used are vacuum deposition, chemical vapor deposition, ion plating and sputtering. The present invention allows the use of energy-absorbing claddings that are not suitable for other types of collectors, such as flat plate collectors, so that the cladding can be used in a high vacuum within the tube-to-tube space 49'. This is because they are protected by the environment.

The chemical attack by air and moisture or the lack of bonding integrity is alleviated and there are no longer harmful agents within the tubular solar energy collector. The spacing means used between the closed ends of the inner tube 41' and the outer tube 40' of the collector may be of any design or material.

Design criteria must be such as to provide firm support of the inner tube end to minimize stress caused by opposing melting ends, or tube opening. The spacing means must be able to expand and contract the inner tube according to its temperature without causing undue stress at the fused joint. The spacing means should also preferably have a minimum contact surface between the tube and the spacing means to minimize heat loss by conduction, and should also act as a support during the sealing operation. be. As shown, the spacing means may include a snap-on clip 46 (FIG. 5) or a coil spring 61 (FIG. 7).
It can take the form of Since the separating means is placed in a highly evacuated space, the material used should not emit gas after the outer tube 40 or 40' is blown off in the evacuation operation.

Also, the material of the spacing means must be free of oily substances and organic adhesives that cannot be removed at the phosphorization temperature for evacuation. Stainless steel, properly cleaned, is the preferred material. Using the described assembly illustrated in FIG. 3, a fluid medium, such as air, is pumped from within the duct 25 to the central passage 20 of the manifold.

The free ends 43b of some of the collectors 14 are sealed flush with the passages 20, so that air can flow through the conveying tubes 4.
3 and exits at the inner end 43a. The sun's rays are
The energy passes through the glass at the top of the tube 40 and is absorbed by the covering material 42 of the absorption tube 41. The air circulated inside the tube 41 traverses the passage defined by the spiral wall plate 44, where heat exchange occurs between the air and the tube 41.
As the air advances toward the free end 41b of the air, the temperature of the air increases. When the heated air reaches the free end 41b of the tube and enters the passage 18 or 19, the heated fluid medium enters the lower duct 26 for heating or cooling the dwelling 10 or for hot water heating. used for or both.

One of the significant advantages of the system has been made with the collector unit 14 or 14' of the present invention.

If any one of the collectors becomes damaged or disabled, replacement is easily accomplished by insertion and the defective unit is removed to preserve the effectiveness of the system. The glass tubes of the unit are of standard glass shapes (
shapes).

Both glasses are relatively inexpensive. Systems and modules can be assembled at the installation site and do not need to be pre-assembled at the factory and transported to the site. The solar energy collector of the present invention is simple to manufacture and assemble, and is also lightweight, so that no further reinforcement of the roof of the building in which it is to be installed is required. In use of the present invention, the working fluid may be conveyed from the collector at temperatures in excess of 25 degrees Fahrenheit.

The energy absorbing covering 42 or 42' is completely protected and can last the lifetime of the cork tunite.
The module concept described above is a preferred example of a "dual action" system where the collector extends on both sides of the manifold.

A collector extends along only one side of the manifold. It is also within the scope of this invention to manufacture "single action" systems. Although this has several special uses, dual action systems are the preferred embodiment.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the invention being used on a pitched roof of a residence. FIG. 2 is a side view of the collector unit of the present invention, showing a partially broken section. FIG. 3 is an exploded perspective view, partially cut away, of a dual manifold example solar energy converter system module with collector units extending from both sides of the manifold. 4 is a cross-sectional view of a portion of the manifold of FIG. 3; FIG. FIG. 5 is a perspective view of an end cap providing an inner end support means for the jacketed absorber tube of the collector within the outer jacket tube. FIG. 6 is a cutaway end view of the collector taken along line 6--6 of FIG. FIG. 7 is a side view of a second specific example of the collector unit of the present invention, showing a partially broken cross section. 8 is a partially enlarged cross-sectional view of the fused assembly of the glass outer tube and glass absorption tube of the collector unit of FIG. 7; FIG. 12... Module, 13... Manifold section, 14, 14'... Collector unit, 15, 15'... Side entrance, 16, 17...
... Opposing vertical side walls, 18, 19... Longitudinal passage, 20... Central passage, 21, 22..., Longitudinal internal vertical wall, 24... Duct, 25...
...Upper conduit passage, 26...Lower conduit passage, 28
... Vertical alignment, 29 ... Face material with gasket, 30 ... Holding screw, 32, 33, 34, 35 ...
...Combination lower Sekiguchi, 40,40'...Outer glass tube, 41...Absorption tube, 42...Energy absorption coating material, 43,43'...Fluid transport Glass tube, 44...Spiral wall plate, 45...Lower mirror surface, 46...Snap-on end support cap, 48,
48'...Chip, 49, 49'...Seal space, 50
...○ ring, 51, 51'...0 ring, 60...
... Wide end, 61 ... Coil spring, 64 ...
Foamed insulation layer, B...Fluid heat exchanger, S...
...Fluid supply V supply means. FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 8 FIG. 7

Claims (1)

[Scope of Claims] 1. A cylindrical outer medium-slender and elongated tubular member 40, 40' made of transparent glass having a circular cross section, with one end closed and the other end 40a open; It is provided coaxially with the outer tube, one side 41a thereof is closed and the other end 41b,
60 includes a cylindrical hollow elongated tubular glass absorption tube member 41, 41' having a circular open cross section and an outer diameter smaller than the inner diameter of the outer tube, the open end of the absorption tube member a single glass composition selected from the group of glasses consisting of soda-lime and silicate glass; the surface of the hollow elongated tubular glass absorption tube member is an annular surface extending over a majority of its axial length on the exterior of the absorption tube member and having an absorption rate of an opaque wavelength-selective coating 42, 42' of an energy-absorbing material with an emissivity of 0.80 or greater and an emissivity of 0.1 or less;
is formed on the annular surface and enclosed within a vacuum space 49, the energy absorbing material 42, 42' of the coating containing a compound selected from the group consisting of chromium, nickel, and copper compounds. , having yielding retaining means 46, 61 at the closed end of the absorption tube to maintain the absorption tube in an axially and circumferentially spaced relationship with the outer tube to provide a space between the tubes. , and means for sealingly coupling the outer tube and the absorption tube member near their open ends 40a, 60, the sealing means comprising an annular glass portion adjacent and surrounding the open end of the outer tube. Symmetrical tubular solar energy collector of circular cross-section, characterized in that by melting the absorber into the absorber tube member, thereby closing the space 49 between the two tubes and creating a vacuum in this space. 2. Connect the absorption tube members 41, 41' to the outer tubes 40, 40'.
The yielding retaining means 46, 61 for holding in a spaced apart relationship have a portion 46 of heat-resistant material fitable in the closed end region of the outer tube and a plurality of spring-like legs 47 in frictional engagement with the end of the absorption tube. A solar energy collector according to claim 1. 3. A solar energy collector as claimed in claim 1, wherein the absorber tube member projects from a normally open end of the outer tube. 4. An annular portion of glass at the open end of the outer tube is annularly fused onto the glass of the absorption tube member near the open end of the absorption tube member, thereby sealing both tube members together and enclosing a space therebetween. A solar energy collector according to claim 1. 5 The spring-like snap-on member that engages the closed end of the absorbent tube member includes a cup-like member having a plurality of outwardly depending resilient legs 47 that engage the closed end 4 of the absorbent tube member.
1a from the outside into frictional engagement with the absorbent tube member and into mating engagement with the closed end of the outer tube, thereby placing the outermost closed end of the absorbent tube member in a spaced relationship with the interior of the outer tube. A solar energy collector according to claim 1 or 2 held in Claims 1 or 2. 6. The open end of the hollow elongated tubular glass absorption tube member 41, 41' is provided with an outwardly flared end, the flared end being connected to the glass of the outer tube 40, 40'. as claimed in claim 1 or 4, wherein the hollow elongated tubular glass absorption tube member 41, 41' and the outer tube 40, 40' are fused to each other, thus sealing the space between the hollow elongated tubular glass absorption tube member 41, 41' and the outer tube 40, 40'. solar energy collector.