DK177832B1 - Fitting device for solar absorber tubes - Google Patents

Fitting device for solar absorber tubes Download PDF

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Publication number
DK177832B1
DK177832B1 DK201370146A DKPA201370146A DK177832B1 DK 177832 B1 DK177832 B1 DK 177832B1 DK 201370146 A DK201370146 A DK 201370146A DK PA201370146 A DKPA201370146 A DK PA201370146A DK 177832 B1 DK177832 B1 DK 177832B1
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DK
Denmark
Prior art keywords
tube
protective glass
ring
mounting tube
absorber
Prior art date
Application number
DK201370146A
Other languages
Danish (da)
Inventor
Jens William Larsen
Original Assignee
Polyteknik As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Polyteknik As filed Critical Polyteknik As
Priority to DK201370146A priority Critical patent/DK177832B1/en
Priority to PCT/DK2014/050057 priority patent/WO2014139536A1/en
Application granted granted Critical
Publication of DK177832B1 publication Critical patent/DK177832B1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S10/00—Solar heat collectors using working fluids
    • F24S10/40—Solar heat collectors using working fluids in absorbing elements surrounded by transparent enclosures, e.g. evacuated solar collectors
    • F24S10/45—Solar heat collectors using working fluids in absorbing elements surrounded by transparent enclosures, e.g. evacuated solar collectors the enclosure being cylindrical
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S80/00—Details, accessories or component parts of solar heat collectors not provided for in groups F24S10/00-F24S70/00
    • F24S80/30—Arrangements for connecting the fluid circuits of solar collectors with each other or with other components, e.g. pipe connections; Fluid distributing means, e.g. headers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S25/00—Arrangement of stationary mountings or supports for solar heat collector modules
    • F24S25/60—Fixation means, e.g. fasteners, specially adapted for supporting solar heat collector modules
    • F24S2025/6004—Fixation means, e.g. fasteners, specially adapted for supporting solar heat collector modules by clipping, e.g. by using snap connectors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/40—Solar thermal energy, e.g. solar towers
    • Y02E10/44—Heat exchange systems

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Photovoltaic Devices (AREA)
  • Joining Of Glass To Other Materials (AREA)

Abstract

The present invention relates to a fitting device for assembling solar absorber tubes (1), each solar absorber tube (1) comprising a protective glass tube (2) enclosing an absorber tube (3), wherein said device comprises a fitting tube (4), which fitting tube (4) has a body (5), a first fastening arrangement adapted to be mounted to an end of said fitting tube (4) for fastening two of said devices together, and a second fastening arrangement adapted to be mounted to another end of said fitting tube (4) for fastening said device to said protective glass tube (2) while avoiding dispersing solar thermal energy, wherein said second fastening arrangement comprises a keeper ring (6) formed for establishing a releasable attachment between said protective glass tube (2) and a portion of said fitting tube (4), a Seeger ring (7) for releasable fastening said keeper ring (6) to said fitting tube (4), a combined heat insulating and air filtering thermo stable ring (8) formed for insertion between said portion of the fitting tube (4) and a corresponding portion of said keeper ring (6), and a sealing ring (9) formed for insertion between another portion of said keeper ring (6) and a corresponding portion of said protective glass tube (2).

Description

i DK 177832 B1
Fitting device for solar absorber tubes Field of the Invention
The present invention relates to fitting devices for assembling solar absorber tubes, wherein each solar absorber tube comprises a protective glass tube enclosing an ab-5 sorber tube, wherein said device comprises a fitting tube, which fitting tube has a body, a first fastening arrangement adapted to be mounted to an end of said fitting tube for fastening two of said devices together, and a second fastening arrangement adapted to be mounted to another end of said fitting tube for fastening said device to said protective glass tube while avoiding dispersing solar thermal energy.
10 Background of the Invention
During the last decade there has been a great increase in the number of installed Concentrated Solar Power (CSP) plants for electrical power generation to the grid and thermal energy generation for industrial use and process heating. There are a few major types of technologies in this field: power tower solutions, parabolic disc solutions, 15 parabolic trough solutions and Fresnel solutions. Common to power tower and parabolic disc solutions is that the solar power is focused to a central point or a central area of absorption of the thermal energy. These thermal absorbers have a typical size ranging from less than one square meter to several square meters. Common to parabolic trough and Fresnel solutions is that the thermal power is focused by moving mirrors to 20 typically horizontally-placed absorber tubes. The length of the absorber tubes may vary from a few meters to several kilometres in one installation.
The absorber tubes, also called receiver tubes, have in general two levels of working temperature. For process heat generation, the working temperature is typically in the 25 range of 200 to 350 C°, whereas for electrical power generation, the working temperature of the fluid in the tubes is in the range of 400 to 550 C°. For the temperature range of 200-350 C°, the absorber tubes will typically be enclosed in a protective glass tube or glass shielding, where in-between the absorber tube and the protective glass tube either atmospheric air or vacuum is present. For the temperature range of 400-550 C°, 30 the absorber tubes are always enclosed in an evacuated protective glass tube, also called vacuum tube receiver. Absorber tubes are normally stainless steel tubes coaxial DK 177832 B1 2 with protective glass tubes and having a thermal absorbing coating laid on their outside and a thermal conductive fluid (e.g., water, oil or liquid salt) flowing inside.
A protective glass tube and an absorber tube have welded or brazed connections at 5 both ends to connect with another protective glass tube and another absorber tube, respectively. Common for all absorber tubes and protective glass tubes in the market today is that they are welded on the construction site. Moreover, if the glass has broken or has been damaged by sandstorms/heavy pollution or if the vacuum condition is compromised, a protective glass tube cannot be easily replaced, as a cutting and a 10 welding operation must be performed. In particular, evacuated protective glass tubes cannot be replaced if the vacuum condition is gone. Thus, the main drawbacks of current solar absorber tubes are that they have to be attached together by a welding operation and the protective glass tubes cannot be easily replaced.
15 CN 2924411 Y relates to an expansion joint flow passage vacuum solar energy heat collection tube, which is composed of an air-bleeding nozzle, a glass tube, a convoluted diaphragm, a metal tube, an O-shaped lock ring, a fixed press disc, an inner sealing plate, an outer sealing plate, a movable press disc, a nut, a right outlet tube, a right end cover, a left outlet tube, a left end cover and a glue sealing groove. The convoluted 20 diaphragm and the metal tube form the expansion joint flow passage, which is arranged in a transparent glass tube. The axis of the flow passage coincides with the axis of the glass tube. The two ends of the glass tube are sealed by end covers. The outlet tubes extend out from the end covers. The convoluted diaphragm compensates the axial length change of the metal tube and prevents the crack at the sealing points and 25 the breakage of the glass tube caused by the thermal expansion in the axial direction.
The space between the glass tube and the expansion flow passage is a vacuum state, which has a good heat-insulating effect, high thermal efficiency and a frost prevention function. The heat collection tube has high pressure tolerance, is convenient to assemble and can be used to assemble solar energy collectors of various purposes. However, 30 CN 2924411 Y does not enable an easy replacement of the protective glass tube and an easy connection of two solar absorber tubes.
3 DK 177832 B1
Hence, there is a need in the technical field of solar absorber tubes of overcoming the aforementioned drawbacks of the state-of-the-art solutions.
Object of the Invention
The object of the invention is to enable an easy assembling and disassembling of solar 5 absorber tubes while avoiding a demanding welding and/or cutting process at the construction site of a solar plant, thus only requiring low-skilled labourers to mount, repair or replace absorber tubes and/or protective glass tubes.
Description of the Invention
The aforementioned and other objects and advantages of the invention are achieved by 10 a fitting device as described in the preamble of claim 1, wherein said second fastening arrangement comprises a keeper ring formed for establishing a releasable attachment between said protective glass tube and a portion of said fitting tube, a Seeger ring for releasable fastening said keeper ring to said fitting tube, a combined heat insulating and air filtering thermo stable ring formed for insertion between said portion of the 15 fitting tube and a corresponding portion of said keeper ring, and a sealing ring formed for insertion between another portion of said keeper ring and a corresponding portion of said protective glass tube.
The advantage of the invention is that of eliminating the need for high-skilled welders 20 and high quality welding and/or cutting operations at the construction site, since a manual, mechanical mounting and dismounting of solar absorber tubes in a CSP plant under construction may be easily performed.
Preferably, said combined heat insulating and air filtering thermo stable ring is made 25 of a fibre material such as a braided glass fibre, or a heat resistant and thermal insolat-ing fabric. Advantageously, said sealing ring is made of a polymer material such as a silicone compound or a fluoro-elastomer material (FPM). An advantage of this embodiment is that of firmly fastening the protective glass tube to the fitting tube and, at the same time, avoiding the dispersion of solar thermal energy.
In an embodiment of the invention, said fitting tube is welded to said absorber tube.
An advantage of this embodiment is that of avoiding leakage of the thermal conduc- 30 DK 177832 B1 4 tive fluid flowing between the absorber tube and the fitting device. Moreover, the welding may be carried out at the manufacturing facility instead of the construction site, thus a most cost effective welding process can be performed and properly inspected.
5
In an embodiment of the invention, the one end of said fitting tube, where said first fastening arrangement is adapted to be mounted, has an outwardly-projected rim, which rim has an inwardly-projected rear portion, wherein said first fastening arrangement comprises a clamping ring having a recess adapted to interlock with said 10 rear portion. An advantage of this embodiment is that of firmly fastening one fitting device to another fitting device by providing an interlocking between the fitting tube and the clamping ring such that the latter is firmly hold in place and does not slip away due to the applied forces, vibrations, etc.
15 In an embodiment of the invention, said rear portion has an angle 0° < a <= 45° with respect to the body of said fitting tube. Preferably, 3° < a <= 45°. Most preferably, a = 15°. An advantage of this embodiment is that of providing an even stronger and reliable interlocking between the fitting tube and the clamping ring.
20 In an embodiment of the invention, a recess is provided at said rim for hosting a sealing. An advantage of this embodiment is that of fixing and air and fluid tightening the fitting device when in contact with another fitting device.
In an embodiment of the invention, towards the one end of said fitting tube, where said 25 second fastening arrangement is adapted to be mounted, an outwardly-, radial-projected portion is provided, which outwardly-, radial-projected portion has a front portion adapted to constrain an axial movement of a supporting means (e.g., a fork) when a solar tube absorber is mounted. Absorber tubes are normally mounted in forks that hold them fixed in the focal point in front of the parabolic reflectors. In the con-30 text of the invention, the forks may be mounted at the fitting tubes, in-between the outwardly-projected rim and the outwardly-, radial-projected portion. An advantage of this embodiment is that of ensuring that the forks do not slip away axially, as they are constrained by the front portion of the outwardly-, radial-projected portion.
5 DK 177832 B1
In an embodiment of the invention, said outwardly-, radial-projected portion has a rear portion extending up to an inner diameter of said protective glass tube. An advantage of this embodiment is that of best supporting the keeper ring when mounted and serving as a lifting support for the delicate and scratch sensitive absorber coating surface 5 of the absorber tube, when the absorber tube is handled in the stock and assembly process.
Hereafter, the invention will be described in connection with drawings illustrating non-limiting examples of a fitting device.
10 Description of the Drawings FIGs.lA-B: Fitting device fastened to a solar absorber tube.
FIG.2: Removal or replacement of a protective glass tube by using the fitting device. FIGs.3A-B: Attachment and fixation of two solar absorber tubes by using the fitting device.
FIG.4: An example of a clamping ring.
15 Detailed Description of the Invention FIG.1A shows a cross-sectional view of a solar absorber tube 1 comprising a protective glass tube 2 coaxially enclosing an absorber tube 3. The absorber tube 3 has a heat absorbing coating 14 deposited on its cylindrical surface. The fitting device includes a fitting tube 4 with an inner diameter equal to the inner diameter of the absorber tube 3 20 and welded to the absorber tube 3 at a welding point 15. The solar absorber tube 1 is fastened to the fitting device by means of an arrangement comprising: a keeper ring 6, which keeps the protective glass tube 2 horizontally- and coaxially-fixed; a Seeger ring 7, which ensures the correct position of the keeper ring 6; a combined heat insulating and air filtering thermo stable ring 8, which is placed underneath the keeper ring 25 6; and a sealing ring 9, which has the function of fixing and air tightening between the protective glass tube 2 and the keeper ring 6. The fitting device is provided with a recess 20 (ref. FIG.IB) at the rim 11 for hosting a sealing 16. The inclined surface 12 having an angle a (e.g., 15°) has an interlocking function together with the clamping ring 10 (ref. FIG.3A).
FIG. IB shows the solar absorber tube 1 in FIG.1A seen from outside. The total length L may typically vary (but not limited to) between 2000 and 6000 mm, and the diame- 30 DK 177832 B1 6 ter of the absorber tube 3 may typically vary (but not limited to) between 25 and 75 mm.
FIG.2 shows an example of how to remove or replace the protective glass tube 2. The 5 Seeger ring 7 may be removed, then the keeper ring 6 and finally the protective glass tube 2. In particular, note that the outwardly-, radial-projected portion, which is positioned towards the end of the fitting tube 4 where the second fastening arrangement was mounted, has its rear portion 19 extending up to the inner diameter of the protective glass tube 2.
10 FIG.3A and FIG.3B show the attachment and fixation between two solar absorber tubes 1 in a cross-sectional view and a lateral view seen from outside, respectively. Bolts 17, nuts 18 and the clamping ring 10 have the function of keeping the two ends tight together. Note that one of the fitting devices is provided with a recess 20 at the 15 rim 11 for hosting the sealing 16.
FIG.4 shows an example of a clamping ring 10 constituted by two half rings. In particular, note the recess 13 in each of the half rings composing the two clamping rings 10.

Claims (9)

1. Monteringsindretning til samling af solfangerrør (1), og hvor hvert solfangerrør (1) omfatter et beskyttende glasrør (2), som omgiver et absorberrør (3), og hvor indretnin-5 gen omfatter et monteringsrør (4), hvilket monteringsrør har et legeme (5), et første fastgørelsesarrangement, som er indrettet til at blive monteret til en ende af monteringsrøret (4) med henblik på fastgørelse af to af indretningerne til hinanden, og et andet fastgørelsesarrangement, der er indrettet til at blive monteret til en anden ende af monteringsrøret (4) med henblik på fastgørelse af indretningen til det beskyttende 10 glasrør (2), idet der undgås spredning af solvarmeenergi, kendetegnet ved, at det andet fastgørelsesarrangement omfatter en holderring (6), der er udformet med henblik på tilvejebringelse af en løsbar fastgørelse mellem det beskyttende glasrør (2) og et afsnit af monteringsrøret (4), en seegerring (7) til løsbar fastgørelse af holderringen (6) til monteringsrøret (4), en kombineret varmeisolerende og luftfiltrerende, varmebe-15 standig ring (8), som er dannet med henblik på indsættelse mellem afsnittet af monteringsrøret (4) og et tilsvarende afsnit af holderringen (6), og en tætningsring (9), der er dannet med henblik på indsættelse mellem et andet afsnit af holderringen (6) og et tilsvarende afsnit af det beskyttende glasrør (2).A mounting device for assembling collector tubes (1), wherein each collector tubing (1) comprises a protective glass tube (2) surrounding an absorber tube (3), and the device comprising a mounting tube (4), which has a mounting tube a body (5), a first fastening arrangement adapted to be mounted to one end of the mounting tube (4) for securing two of the devices to each other, and a second fastening arrangement adapted to be mounted to a second end of the mounting tube (4) for securing the device to the protective glass tube (2), avoiding the dissipation of solar thermal energy, characterized in that the second fixing arrangement comprises a retaining ring (6) designed to provide of a detachable attachment between the protective glass tube (2) and a portion of the mounting tube (4), a retaining ring (7) for detachable attachment of the mounting tube (6) to the mounting tube t (4), a combined heat-insulating and air-filtering, heat-resistant ring (8) formed for insertion between the section of the mounting tube (4) and a corresponding section of the holder ring (6), and a sealing ring (9) formed for insertion between a second portion of the retaining ring (6) and a corresponding portion of the protective glass tube (2). 2. Indretning ifølge krav 1, kendetegnet ved, at den kombineret varmeisolerende og luftfiltrerende, varmebestandige ring (8) er fremstillet af et fibermateriale.Device according to claim 1, characterized in that the combined heat-insulating and air-filtering, heat-resistant ring (8) is made of a fibrous material. 3. Indretning ifølge krav 1 eller krav 2, kendetegnet ved, at tætningsringen (9) er fremstillet af et polymermateriale. 25Device according to claim 1 or claim 2, characterized in that the sealing ring (9) is made of a polymeric material. 25 4. Indretning ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at monteringsrøret (4) er svejst til absorberrøret (3).Device according to any of the preceding claims, characterized in that the mounting tube (4) is welded to the absorber tube (3). 5. Indretning ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at 30 den ene ende af monteringsrøret (4), hvor det første fastgørelsesarrangement er indrettet til at blive monteret, har en udad rettet kant (11), hvilken kant (11) har et indad rettet, bageste afsnit (12), og hvor det første fastgørelsesarrangement omfatter en DK 177832 B1 8 spændering (10), som har en udsparing (13), der er indrettet til at låse sammen med det bageste afsnit (12).Device according to any one of the preceding claims, characterized in that one end of the mounting tube (4), wherein the first fastening arrangement is arranged to be mounted, has an outwardly directed edge (11), which edge ( 11) has an inwardly directed rear portion (12), and wherein the first fastening arrangement comprises a clamp (10) which has a recess (13) adapted to lock in with the rear portion (12) ). 6. Indretning ifølge krav 5, kendetegnet ved, at vinklen mellem det bageste afsnit (12) 5 og monteringsrørets (4) legeme (5) har en størrelse 0° < (alfa) <= 45°Device according to claim 5, characterized in that the angle between the rear section (12) 5 and the body (5) of the mounting tube (4) has a size 0 ° <(alpha) <= 45 ° 7. Indretning ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at der i kanten (11) er tilvejebragt en udsparing (20) med henblik på at kunne rumme en pakning (16). 10Device according to any one of the preceding claims, characterized in that a recess (20) is provided in the edge (11) for accommodating a gasket (16). 10 8. Indretning ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at der hen imod monteringsrørets (4) ene ende, hvor det andet fastgørelsesarrangement er indrettet til at blive monteret, er tilvejebragt et udad rettet, radialt fremspringende afsnit, hvilket udad rettede, radialt fremspringende afsnit har et frontafsnit, der er indret- 15 tet til at begrænse aksial bevægelse af et støttemiddel, når der monteres en solfanger-rørabsorber.Device according to any one of the preceding claims, characterized in that an outwardly directed radially projecting portion is provided towards one end of the mounting tube (4), where the second fastening arrangement is arranged to be mounted. directed radially projecting portions have a front portion adapted to restrict axial movement of a support when a collector tube absorber is mounted. 9. Indretning ifølge krav 8, kendetegnet ved, at det udad vendende, radialt fremspringende afsnit har et bageste afsnit (19), som strækker sig op til en indre diameter for det 20 beskyttende glasrør (2).Device according to claim 8, characterized in that the outwardly radially projecting portion has a rear portion (19) extending up to an inner diameter of the protective glass tube (2).
DK201370146A 2013-03-12 2013-03-12 Fitting device for solar absorber tubes DK177832B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DK201370146A DK177832B1 (en) 2013-03-12 2013-03-12 Fitting device for solar absorber tubes
PCT/DK2014/050057 WO2014139536A1 (en) 2013-03-12 2014-03-12 Fitting device for absorber solar tubes

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK201370146 2013-03-12
DK201370146A DK177832B1 (en) 2013-03-12 2013-03-12 Fitting device for solar absorber tubes

Publications (1)

Publication Number Publication Date
DK177832B1 true DK177832B1 (en) 2014-09-01

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WO (1) WO2014139536A1 (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3933733A1 (en) * 1989-10-09 1991-04-11 Guenter Dr Wiedner Solar radiation receiver - with silicone sealed intermediate piece for two tube parts enclosing collector tube
US7398779B2 (en) * 2005-03-31 2008-07-15 Fafco, Incorporated Thermosiphoning system with side mounted storage tanks
IT1403761B1 (en) * 2011-01-10 2013-10-31 Umbra Meccanotecnica CONNECTORS FOR SOLAR CONCENTRATION SYSTEMS.

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