Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
  • F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
  • F24S23/77—Arrangements for concentrating solar-rays for solar heat collectors with reflectors with flat reflective plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
  • F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
  • F24S23/82—Arrangements for concentrating solar-rays for solar heat collectors with reflectors characterised by the material or the construction of the reflector
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
  • G02B7/18—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors
  • G02B7/182—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors
  • G02B7/183—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors for mirrors specially adapted for very large mirrors, e.g. for astronomy, or solar concentrators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
  • F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
  • F24S2023/87—Reflectors layout
  • F24S2023/874—Reflectors formed by assemblies of adjacent similar reflective facets
• • 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
  • F24S2025/601—Fixation means, e.g. fasteners, specially adapted for supporting solar heat collector modules by bonding, e.g. by using adhesives
• • 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

Definitions

• the present invention relates to a tool for mounting reflective facets, especially applicable as components of heliostats for central tower solar thermal plants.
• the invention is also directed to the assembly system of said reflective facets.
• the tool and system of the invention fall within the field of solar thermal energy.
• a facet basically consists of a reflective sheet, such as a mirror, generally flat, and a support that provides the necessary stiffness to guarantee its optical performance.
• the reflective sheet is fixed on the support by means of an adhesive.
• the current adhesive systems of the mirror with the support to form the facet are directly conditioned by its configuration, although most agree that the adhesive process is performed with the reflective surface placed "face down” against a surface that provides the desired shape (flat or with a certain curvature).
• the manufacture is carried out so far by means of a metal tool of tubes in the form of stringers and crossbars welded together on which polyamide plugs are fixed that are subsequently machined to achieve the Support surface of the desired mirror.
• the mirror In the manufacture of the facet by means of this type of tool, the mirror is positioned "face down" resting on the polyamide studs. After applying the adhesive on the non-reflective face of the mirror, the metal support of the facet is deposited on the adhesive, adapting it to the geometry also aided by the force of gravity. The mirror, adhesive and stamped support remains in the tool for the necessary time until the adhesive is cured after which the facet is demoulded.
• This "upside down” manufacturing system suffers from the following disadvantages:
• the positioning of the metal support on the adhesive that has been previously deposited on the non-reflective side of the mirror is done by means of a manipulator.
• the support is elastically deformed due to its low rigidity due to the pressure exerted by the manipulator at discrete points thereof so that, depending on the viscosity of the adhesive, said deformations can remain remaining in the support adopting the reflective surface of the facet an unwanted geometry.
• the metal support After being released by the manipulator, the metal support floats freely by gravity on the adhesive without anything that keeps it in position, so it can suffer displacements during the beginning of its curing when the tool travels through the automated manufacturing line.
• the final thickness of the adhesive cord is uncontrolled, leaving areas with barely any thickness of adhesive and other areas where the support does not adapt completely by gravity to the geometry defined by the tool, mainly at the ends of the facet, with excessive thickness of adhesive or even without adhesive.
• the tool is designed to be stacked one on top of the other during curing, so that the possible deformations due to the lack of flatness of the surface on which they rest or due to the total weight of the assembly are transmitted from one to another, inducing said deformation, undesirable and uncontrolled, to the facets.
• the facet once the adhesive has cured must be demoulded and turned off the tool, making it difficult to automate the process.
• the present invention aims to eliminate the problems described above, by means of a tool with which, in the facet assembly phase, the facet support is positioned first on the tool and then the reflective sheet is positioned on the support, with the reflective surface directed upwards, so that the risk of the support undergoes unwanted deformations and also that the reflective surface is damaged.
• the mounting system of the invention allows controlling the relative positioning between support and reflective sheet, as well as the thickness of the applied adhesive.
• the tool for mounting reflective facets is constituted by a rigid flat structure, which has on its upper surface supports for the facet support, supports for the facet mirror, centering for the facet and center support for the reflective sheet, while on the lower surface it has projections that define a support plane for said flat structure.
• the flat structure mentioned can take the form of a grill, composed of stringers and rectangular metal tube cross members welded together.
• the projections of the lower surface of the structure can be constituted by three spherical support points located at the bottom of the grill, which will define a support plane to support the tool in the facet assembly process.
• the grid that forms the flat structure will also have openings for the passage of elevators that act on the facet support, in the assembly phase of the same.
• the supports for the facet support and for the reflective sheet consist of protrusions that protrude from the upper surface of the flat structure, the projections defining the supports for the reflective sheet being higher than the projections defining the support supports .
• both supports will be positioned so that during the facet assembly process they minimize the deformation of the support and reflective sheet.
• the said projections may consist of studs of metallic or polyamide material that will independently support both the metal support and the reflective sheet, these studs being machined to achieve the desired geometry and dimensions.
• the centers for the facet support protrude from intermediate points of the upper surface of the flat structure and can consist of two faces facing as many holes of the facet support, to allow the centering of said supports on the tool.
• the centers of the reflective sheet are located on the periphery of the structure, to serve as stops against which the edges of the reflective sheet will rest, thus ensuring their centering on the tool.
• the grid that forms the flat structure of the tool also has openings for the passage of elevators that act on the facet support, during the process of dimensional control of the same after its manufacture.
• the tool with the constitution described above is arranged in a horizontal position, then positioning the facet support on the tool, with the support surface of the reflective sheet directed upwards .
• the facet support is correctly positioned on the tool, through the supports and centering of the tool for said support.
• the upper surface of the support on which the reflective sheet of the facet will rest is adhesive.
• the reflective sheet of the facet is then positioned on the support, with the reflective surface facing up.
• the reflective sheet will rest on the supports of the tool, with a separation of the facet support that will correspond to the desired final thickness of the adhesive cords.
• the correct positioning of the reflective sheet is achieved by the centering of the tool for said sheet.
• the facet is separated from the tool, and supporting the facet only at its interface points, the reflective surface is measured to finally disassemble the facet of the tool for palletizing and storage with adequate protection.
• the attached drawings show a tool for the assembly of reflective facets, constituted according to the invention and given as a non-limiting example.
• Figure 1 is a lower floor of a facet for reading data.
• Figure 2 is a cross section of the same facet, taken along the lili cut line of Figure 1.
• Figures 3 and 4 show in upper and lower perspective, respectively, the tool for mounting the facet shown in Figures 1 and 2.
• Figure 5 is a perspective similar to Figure 3, with the face support mounted on the tool.
• Figure 6 is a perspective similar to Figure 5, with the support and reflective sheet that forms the facet mounted on the tool of the invention.
• Figure 7 is a schematic cross-section, of the assembly shown in Figure 6, to conceptually show the different elements of the tool and the arrangement of the facet components.
• a facet which is composed of a support 1 and a reflective sheet 2.
• the support 1 may be constituted of stamped sheet on which the reflective sheet 2 is fixed by means of adhesive cords 3, with the reflective surface directed outwards.
• the support 1 has punching interface points 4, for fixing the facet to the heliostat structure, as well as holes 5 for centering the support 1 in the tool of the invention, as will be explained later.
• FIGS 3 and 4 a tool 6 for mounting the facet shown in figures 1 and 2 is shown in upper and lower perspective.
• This tool 6 comprises a rigid flat structure, in the form of a grill, which can be composed of stringers 7 and crossbars 8 of metal pipes of rectangular section, welded together.
• This structure is a carrier in its upper base of a series of studs 9 and 10, of a metallic or polyamide nature, which define independent supports for the support 1 and the reflective sheet 2, of the facet, respectively, the studs 10 being define the supports for the reflective sheet of greater height than the studs 9 that constitute the supports of the facet support.
• These supports are mechanized to achieve the desired geometry and height.
• the flat structure of the tool 6 also has on its upper surface centers 1, in the form of lugs, for centering the metal support of the facet on the tool and centers 12, preferably polyamide, for centering the reflective sheet 2 of the facet on the tool, which are arranged in the outline of the structure of the tool 6.
• the tool 6 has on its lower surface three support points 14, of spherical configuration, which define a support plane for the tool.
• the structure of the tool 6 has, between its upper and lower surface, passages 15 for the passage of elevators that will act on the support 1 of the facet, during the dimensional control phase thereof, as will be explained later .
• Other materials and / or configurations for its construction may be admissible, as long as the aforementioned rigidity of the assembly is guaranteed.
• a configuration using four support points can also be valid, as long as the coplanarity between them is guaranteed.
• Both the support 1 and the mirror 2 of the facet are received in the tool of the invention resting completely independently on the supports 9 and 10, constituted by metal, polyamide or any other polymeric material machined to the desired shape.
• the discrete distribution of the supports 9 and 10 is strategically carried out so that they are in adequate number and positions, so that in the phase of facet assembly the deformations of the support 1 and reflective sheet 2 are minimized, when they rest on the supports .
• the studs that configure the supports 9 and 10 are fixed to the structure by any type of removable or permanent joint, for example based on joining elements, such as screws, rivets, adhesive, etc. In order that the heads of said fixing elements do not protrude from the support surface of the block and could scratch or damage the support and / or the protective layers of the mirror, they are made embedded in the blocks.
• the detachable fasteners have the advantage that the height of the machined face of the studs that make up the supports 9 and 10 can be adjusted by means of gauges if required in an initial phase of commissioning of the manufacturing tool.
• the support 1 thereof will rest on the supports 9 by the external surface of the different arms V, figures 1 and 2, formed by the stamping.
• the nominal thickness of the adhesive cord 3 will be defined by the relative vertical distance between the surfaces of the supports 9 and 10 for the support 1 and the reflective sheet 2 of the facet, said distance should be close to the flatness tolerance value of the support. In this way there will be areas where the support 1 is close to touching the mirror (low adhesive thickness) and areas where the distance is maximum (adhesive thickness 3 high), it being necessary that the adhesive 3 has sealing capacity and resistance in a thickness range close to said flatness value of the support.
• the centering of the support can also be done using any other feature provided in the support and having sufficient dimensional quality.
• side centers 12, figure 3 are available on the outer contour of the tool 6. These centers may be made of polyamide or any other polymeric material sufficiently resistant to wear.
• a valid alternative for the construction of the adhesive tool is to start from a lighter and, therefore, less rigid structure of stringers and crossbars, to which a plate of sufficient thickness is mechanically fixed or welded to achieve the necessary stiffness that closes the grill on one side.
• the studs defining the supports 10 for the reflective sheet are fixed on this plate.
• Both the plate and the studs are subsequently machined to the required height, the former serving as support of the support 1 and the latter as supports of the reflective sheet 2.
• the support 1 of the facet, to which the reflective sheet is adhered can be of other materials and shapes other than stamped metal, for example based on mechanically bonded lightweight profiles, of reinforced or unreinforced polymeric material, etc., provided and when it has enough gaps within its geometry to allow enough tacos to pass through the reflective sheet.
• the tool 6 rests on the lower spherical studs 14 that define its support plane. From the upper surface of the tool 6, the supports 9 protrude on which the arms V of the support 1 of the facet will rest, said support being positioned through the centerpieces 11. Of the upper surface of the tool 6, the supports 10 also stand out on which the reflective sheet 2, positioned by the lateral centers 12, rests.
• the tool moves along the line, in the position shown in figure 3, by means of a continuous moving drag system.
• an automatic system hydraulic, pneumatic or electromechanical raises the tool by releasing it from the line's drag system and fixing it in the working position.
• An alternative option may be that the tool drag system is started and stopped when necessary, avoiding having to release the tool by lifting it.
• Both systems must also guarantee the correct positioning of the tool in each position of the line.
• the load is carried out by means of a manipulator, not shown, of the support 1 on the tool 6 being centered by means of its punching 5 and by the centering 1 1 of the tool, in the position shown in Figure 5.
• the support 1 is supported by the underside of its stamped arms 1 ', on all corresponding supports 9.
• the loading of the reflective sheet 2, figure 6, is carried out, on which, as in the support, the cleaning and surface preparation operations of the non-reflective face have been previously carried out along the line.
• This reflective sheet is centered with respect to the support 1 by means of the centers 12 located on the outer perimeter of the tool 6 and supported on all corresponding supports 10, figure 3.
• the tool 6 After adhesive of the reflective sheet 2 to the support 1, the tool 6 advances to the fourth position of the line, the curing zone.
• the tool remains in this area on its three lower spherical supports 14 at a controlled temperature, for the time necessary for the adhesive 3 to acquire sufficient strength for handling, without suffering permanent deformations.
• the tool moves to the fifth dimensional control post, also at a controlled temperature.
• a lifting system for example with pneumatic, hydraulic or any other type of cylinders, access through the passages 15 provided in the lower part of the tool, figure 4, to points 4 for fixing the facet to the heliostat, figure 1 , releasing said facet of its supports on the tool 6. With the facet supported on the four interface points 4, the measurement of the reflective surface is made, descending again on the tool at the end of the dimensional control, advancing the tool to the last position of the line.
• the tool and facet mounting system described have the following advantages: - When manufacturing "face up”, the reflective surface of the mirror is seen so that a fully automated dimensional control is possible without the need to unmold and previously flip the facet.
• the relative positioning between the metal support and the mirror is at all times controlled, preventing displacement during curing. Due to the previous point, the thickness of adhesive is also controlled, being the one in charge of absorbing through its sealing capacity the tolerance of lack of flatness, mainly of the metallic support.
• the present invention manages, on the one hand, to improve the dimensional quality of the mirror surface to the desired levels and, on the other, to automate 100% of the manufacturing process, including dimensional control.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Combustion & Propulsion (AREA)
• Sustainable Energy (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Astronomy & Astrophysics (AREA)
• Optical Elements Other Than Lenses (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Road Signs Or Road Markings (AREA)
• Aerials With Secondary Devices (AREA)
• Earth Drilling (AREA)

Priority Applications (4)

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Citations (4)

Family Cites Families (6)

• 2012
  • 2012-12-28 ES ES201232057A patent/ES2472340B1/es not_active Expired - Fee Related
• 2013
  • 2013-12-05 CN CN201380068383.XA patent/CN104884875B/zh not_active Expired - Fee Related
  • 2013-12-05 WO PCT/ES2013/070850 patent/WO2014102415A1/es active Application Filing
  • 2013-12-26 JO JOP/2013/0388A patent/JO3119B1/ar active
• 2015
  • 2015-06-26 CL CL2015001872A patent/CL2015001872A1/es unknown
  • 2015-06-28 SA SA515360690A patent/SA515360690B1/ar unknown
  • 2015-06-29 MA MA38228A patent/MA38228B1/fr unknown
  • 2015-07-03 ZA ZA2015/04818A patent/ZA201504818B/en unknown

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