WO2012041583A1

WO2012041583A1 - Thermosolar cladding element

Info

Publication number: WO2012041583A1
Application number: PCT/EP2011/063593
Authority: WO
Inventors: Christian Kipfelsberger; Werner Guckert; Siegfried Rauch; Robert Michels
Original assignee: Sgl Carbon Se
Priority date: 2010-09-30
Filing date: 2011-08-08
Publication date: 2012-04-05
Also published as: DE102010041822A1

Abstract

The invention relates to a thermosolar cladding element (5a-f) for outer façades and/or roofs of buildings, comprising a substrate (6) that contains graphite. According to the invention, the substrate (6) has a density of at least 0.6 g/cm³, preferably at least 1.0 g/cm³.

Description

Thermosolares cladding element

The invention relates to a thermosolar cladding element for facades and / or roofs of buildings according to the preamble of claim 1.

The prior art includes graphite-containing absorber components for thermosol applications, e.g. Solar thermal flat-plate collectors, known. For example, EP 1 688 684 A1 discloses an absorber component for solar thermal flat collectors in which tubes through which a heat transfer fluid flows are embedded in a layer of expanded graphite, the surface of which facing the solar irradiation being provided with an absorber layer. The absorber layer is then installed in a conventional manner in a flat collector.

DE 10 2007 053 225 A1 discloses a tempering body for photovoltaic modules, in which heat transfer tubes are embedded in a compressed graphite expander layer and connected to the surface of a photocell layer facing away from the solar radiation.

From DE 10 2005 029 051 A1 discloses a heat conduction device for floor, wall or ceiling heating of interiors is known, in which for stabilization a support plate made of a non-graphite expander material is used and a heat-conducting layer, are embedded in the pipes containing graphite expandate.

The above-mentioned known components have in common that the local graphite layer is only slightly compressed in the thickness direction, so as not to impair their thermal conductivity in this direction. However, this results in a low stability of the graphite layer, so that additional support layers of non-graphite-containing materials must be provided for reasons of stability, as indicated in DE 10 2005 029 051 A1. However, this requires an increased effort in the production and also in the processing and assembly of the components and increases their weight. In order to impart a higher stability to a heat conduction plate made of graphite expandate with a density of 0.01 to 0.5 g / cm ³ and preferably of 0.05 to 0.25 g / cm ³ , DE 103 41 255 B4 proposes to completely or partially impregnate the heat conducting plate with plastics, such as resins or thermoplastics, after the pressing, in order to increase the impermeability and the resistance to mechanical and other environmental influences. However, this subsequent liquid impregnation of the compressed graphite expandate has the disadvantage that the infiltration of the expanded, compacted graphite with the liquid binders is uneven. For example, films made of compressed graphite expandate have been found to be uniformly infiltrated only in a near-surface area. In more interior areas of the films penetrates the binder only insufficient or not at all. The same applies to an even greater extent for the sheets of compressed graphite expandate, which are significantly thicker compared to foils. This uneven distribution of the binder results in uneven stiffness and stability of the panels, making them easier to break at locations not recognizable from outside than at others.

The group consisting of graphite-known components are compacted only up to a maximum density of 0.5 g / cm ^3, since a higher compression adversely affects the heat conductivity.

In Fig. 1 is a schematic cross section through such a lightweight heat conduction plate 1 is shown. There is slightly compressed graphite expander 2 from the side surfaces of the plate 1 was subsequently infiltrated with a liquid binder 3. However, the binder 3 has penetrated the plate 1 only unevenly, so that in particular a region 4 characterized by the oval, dashed border is binder-free and thus significantly less rigid and stable than adjacent regions of the plate 1. The area 4 is thus more vulnerable to breakage than the adjacent areas of the plate 1.

Due to their inhomogeneous dimensional stability and low resistance to external influences, such heat-conducting plates are not suitable for hard use in the construction sector, in particular in the exterior of buildings. It is therefore an object of the invention to provide a thermosolar cladding element for facades and / or roofs of buildings, which overcomes the disadvantages mentioned above and is lightweight, dimensionally stable, thermally well-acting, easy to manufacture and ready to assemble and easy to handle and assemble.

This object is achieved by a thermosolar cladding element with the features of claim 1 or claim 2 and by the use of such a cladding element having the features of claim 19. Advantageous developments and preferred embodiments of the cladding element are specified in the dependent claims.

An inventive thermosolar cladding element is characterized in that the carrier layer has a density of at least 0.6 g / cm ³ , preferably at least 1.0 g / cm ³ . An alternative or additional embodiment of the invention provides that a thermosolar cladding element is characterized in that it contains a solidified mixture of largely evenly distributed graphite particles and plastic particles. Such a cladding element can advantageously be produced by first mixing the graphite particles and plastic particles into a mixture having a substantially uniform distribution of the graphite particles and plastic particles, and then solidifying the mixture.

In one or both of these ways, the cladding element according to the invention can be made so stable that it can be used for robust use on exterior facades and / or roofs of buildings both during installation and when installed.

The carrier layer may preferably contain compressed graphite expandate, in particular graphite expandate-containing graphite particles. Graphite expandate has, among other things, the advantage of better connectability of the graphite expandate particles to one another compared to other forms of graphite, for example graphite powders of natural or synthetic graphite or nanocarbon tubes. In a preferred embodiment, the graphite particles and plastic particles can be distributed homogeneously in the mixture, which can be achieved inter alia by sufficiently long mixing of the particles. In a production-technically advantageous embodiment, the cladding element can consist exclusively of the mixture of graphite particles and plastic particles without having to add further additives.

Advantageously, the mixture may contain 5 to 90% by weight, preferably 15 to 60% by weight and more preferably 20 to 50% by weight, of plastic particles in order to obtain a sufficiently stable cladding element.

The plastic particles may advantageously contain thermoplastics and / or thermosets. In a preferred embodiment can be used as plastic PVC, since it can also be used at temperatures above 80 ° C. This is particularly advantageous in the advantageous use of the cladding element according to the invention as a thermosolar cladding element on the outer facades and / or roofs of buildings, especially when a heat transfer fluid is passed through pipes in the cladding element, since usual operating temperatures of such fluids are up to 60 ° C. Polypropylene (PP), polyamides (PA), acrylonitrile-butadiene-styrene (ABS), polyether ketone (PEEK), polyvinylidene fluoride (PVDF), fluoropolymers, benzoxazines and / or polysulfone (PP) can advantageously be used as further suitable thermoplastics for the plastic particles , A suitable thermoset is preferably epoxy resin, which is widely used, easy to process, relatively inexpensive and temperature resistant. Phenol resins can advantageously be used for higher demands, as well as melamine resin, urea resins and polyester resins, in particular unsaturated polyester resins (UP resins).

Preferably, the solidification of the mixture by compression, in particular by means of compression, take place. Also, the solidification may include a melting and a cooling step to partially or completely melt, for example, thermoplastic resin particles. This makes it possible to achieve a good bond between graphite particles and plastic particles. Particularly in the case of the use of thermosets as plastic particles, solidification can hardening step include. Also, the solidification can be done by an alternative or additional sintering of the mixture.

In an advantageous development of the invention, the carrier layer may contain one or more phase change materials. As a result, the heat storage capacity of the cladding element can be increased Thus, in times of strong sunlight energy in a phase of the phase change material can be stored, which is then released when cooling the outside temperature by the transition of the phase change material in its other phase in the carrier layer. Preferably, the phase change material may be paraffin, and more preferably soft paraffin. Advantageously, the phase change material can be chosen so that its phase change temperature is selected according to the ambient temperature.

Preferably, the carrier layer may be at least 0.5 cm, preferably at least 1 cm thick, so that the cladding element is easy to handle. In this case, the thickness of the carrier layer can advantageously be slightly larger than the diameter of the tubes or pipeline, so that they are completely surrounded by the carrier layer. Thus, prefabricated cladding elements can already be provided ex works.

In an advantageous development of the invention, an absorber layer for converting solar radiation into heat can be arranged on the side of the carrier layer assigned in the installed state to an outer facade or a roof of the solar radiation. This can improve the conversion of solar energy radiated onto the facade or the roof into heat energy.

In order to advantageously increase the stability and robustness of the cladding element, a protective layer may be provided on the side of the carrier layer or optionally the absorber layer assigned to the solar irradiation, for example a mesh fabric or a protective film. Alternatively or additionally, the cladding element on its side facing the sun, in particular on the support layer or the absorber layer, pretreated to receive plaster and / or color, in particular roughened.

In an advantageous embodiment, the cladding element may be plastically deformable, so that it can be easily formed at the installation site to predetermined contours of walls or ceilings of rooms, such as edges, bends, corners, friezes, etc. Optionally, the cladding element can then be finally solidified at the installation location, for example by heating the still plastically deformable cladding element in the installed state. Alternatively or additionally, the cladding element may be formed in a predetermined contour in order to be able to be brought as quickly as possible to its intended position on the facade or the roof at the installation location.

Advantageously, the above-mentioned inventive thermosolar cladding element can be used for the exterior cladding of facades and / or roofs of buildings, as it has in contrast to the known components necessary for the robust use in the outdoor area of buildings stability. In particular, for use for external cladding of buildings, the conventional components prove due to the required ease of handling at the same time great resistance to external influences, especially mechanical and weather-related nature, not suitable.

For the advantageous use of the cladding element according to the invention for cladding external facades or roofs and / or as a thermally active component for cooling or heating of rooms, the mixture can first be pre-consolidated so that it remains plastically deformable. Subsequently, at least one component, advantageously pipes or pipelines, for receiving a heat transfer fluid, be pressed into the still plastically deformable mixture. Additionally or alternatively, advantageously, the plastically deformable mixture or the thus plastically deformable cladding element can be molded to a predetermined contour, for example in order to be formed on non-planar wall or ceiling slopes. Subsequently, subsequently the plastically deformable mixture or cladding element can be finally consolidated. Alternatively, it can be advantageously provided that before solidifying the Mixture at least one above-mentioned component introduced into the mixture and subsequently the mixture is finally solidified. As components advantageously fasteners, anchors, etc. can be embedded.

The production of expanded graphite, ie expanded graphite, is well known from the prior art, inter alia from US Pat. No. 3,404,061 A or DE 103 41 255 B4. Thus graphite intercalation compounds or graphite salts, such as, for example, graphite hydrogen sulfate or graphite nitrate, are shock-heated to produce graphite expandate. The volume of the graphite particles increases by a factor of about 200 - 400 and at the same time the bulk density drops to values of 2 - 20 g / l. The graphite expandate thus obtained consists of worm-shaped or accordion-shaped aggregates. The graphite expandate is compacted under the direction of a pressure, so that the layer planes of the graphite preferably arrange perpendicular to the direction of action of the pressure and the individual units interlock with each other. Although compacted heat conducting plates without binders, produced according to DE 103 41 255 B4, are basically dimensionally stable, they have a low strength, so they break apart slightly at relatively low loads. For example, rectangular heat conducting plates having a basis weight of 1000 g / m ² , a thickness of 13 mm and the size 1 1 x 13 cm, ie a density of 0.08 g / cm ^3, only a bending strength of 0, 1 MPa. It can therefore only dimensionally stable plates with relatively small dimensions, eg

50 x 50cm are made, as larger plates are no longer manageable. In particular, even the weight of larger plates causes the plate breaks when lifting at the side edges.

Other features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. Show it:

Fig. 1 is a known from the prior art graphite-containing plate;

2 shows a cross section through a cladding element after a first

Embodiment of the invention; 3 shows a cross section through a cladding element according to a second embodiment of the invention.

4 shows a cross section through a cladding element after a third

Embodiment of the invention;

Fig. 5 shows a cross section through a cladding element according to a fourth

Embodiment of the invention;

6 shows a cross section through a cladding element according to a fifth

Embodiment of the invention;

7 shows a cross section through a cladding element after a sixth

Embodiment of the invention.

A plate-shaped thermosolar lining element 5a shown in cross-section in FIG. 2 has a carrier layer 6 of compressed graphite expanse 7. For the known production of graphite expander 7 reference is made to the above statements. In order to ensure the stability and robustness of the cladding element 5a necessary for use as a roof or exterior cladding, the graphite expander 7 in the present embodiment is compacted to a density of 1.0 g / cm ³ and a thickness of 2 cm.

This makes it possible to disguise an exterior facade and / or a roof of a building quickly with cladding elements 5a, by these with known fastening means, such as applying an adhesive on the building facing side of the cladding elements 5a, positively on the outer facade and / or the roof of the Building to be installed. In this case, a thermally conductive adhesive is advantageously used, so that a good thermal coupling between carrier layer 6 and outer facade and / or roof is made. Since the cladding element 5a is sufficiently stable, it can be easily and quickly transported and mounted on the one hand without risk of breakage when carrying or attaching to the building site, on the other hand, it can easily due to the structure of the graphite expander 7 in the Cut the required sizes or cut out recesses for components protruding from the facade.

An inventive cladding element 5b shown in FIG. 3 differs from that shown in FIG. 2 in that on the one hand, it has an absorption layer 8 on its upper side, which is in the installed state on the outside of the building. By means of the absorption layer 8, the incident on the cladding element 5b direct solar radiation as well as indirect radiation by reflected solar radiation or diffused sunlight in a conventional manner is particularly efficiently converted into heat. The absorption layer 8 can consist of materials known per se, the production, structure and composition of the absorption layer 8 and the attachment of the absorption layer 8 to the carrier layer 6 are known from the prior art, for example EP 1 688 684 A1.

The absorption layer 8 is preferably fastened to the carrier layer 6 with such fastening means that good heat transfer takes place. Examples of such agents are electrically conductive adhesives whose electrically conductive additives such as carbon black or metal particles are also thermally highly conductive, or special thermal adhesive.

Through the absorption layer 8, the solar radiation irradiated thereon is converted into heat, which is then introduced into the carrier layer 6. The registered in the carrier layer 6 heat energy is then registered at least partially in the outer facade and / or roof, in particular with good heat coupling between the support layer 6 and the outer facade and / or roof, which are heated thereby.

Due to the heat storage capacity of the carrier layer 6, the heat stored in times of strong solar radiation, eg during the day, in the carrier layer 6 of the cladding element 5a or 5b can cool the outer facade and / or the roof and thus the interior of the building in times of lacking or low solar radiation, eg in the evening or at night, delay. On the other hand, the embodiment of the invention according to FIG. 3 according to the invention, to increase the heat storage capacity of the lining element 5a of the support layer 6 advantageously a phase change material 9, such as paraffin or special, known per se salts with phase change properties to attach. The phase change material 9 can advantageously be inserted into the carrier layer 6 before solidification. Due to the phase change material 9, heat which arises in the carrier layer 6 during times of strong solar radiation can be stored in a phase of the phase change material 9, preferably the liquid phase. When the outside temperature drops below the phase change temperature of the phase change material 9, it passes into its other, preferably solid phase, with the release of heat, so that the carrier layer 6 is heated and thus the cooling of the building is slowed down.

A further embodiment of a cladding element 5c according to the invention shown in FIG. 4 substantially corresponds to the embodiment 5b shown in FIG. 3 with the absorber layer 8, but without phase change material 9. The cladding element 5c additionally has two conduit tubes 10 embedded in the carrier layer 6. The conduits 10 are embedded in this prior to compacting the graphite expander 7, which is then compressed in a conventional manner by applying a pressure. The conduit 10, which are connected to a heating circuit of the building, are used in a conventional manner for passing a heat transfer fluid, for example water a heating system. The heat transfer fluid absorbs heat energy introduced by the solar radiation onto the cladding element 5c in the carrier layer 6 and can thus be used to support the hot water production in the heating system of the building.

In addition, the cladding element 5c from FIG. 4 provides that a protective layer 11 is applied to the irradiation side of the absorption layer 8 facing away from the carrier layer 6. The protective layer 11 may, for example, be a water-repellent layer, a plaster layer or a color layer which protects the cladding element 5c from external mechanical and / or weather-related influences. The cladding element 5d differs from that shown in FIG. 2 in that the carrier layer 6 consists of a solidified mixture of expanded graphite particles 7 and solid plastic particles 12, here PVC. The graphite particles 7 are first substantially uniformly, ie at least 85%, mixed with the solid plastic particles 12 in order to obtain a uniformly stable cladding element 5a. Preferably, the particles 7, 12 are homogeneously mixed together. The mixture is carried out in a conventional manner by known mixing devices for powder materials.

Instead of the graphite expandate 7, it is also possible to use natural graphite or synthetic graphite, preferably in powder form. However, the graphite expander 7 has the advantage that on the one hand it can be pressed well into a dense lining element 5d and on the other hand it can readily be mixed with the solid plastic particles 12.

After mixing, the mixture is compressed in a known manner by pressure to the cladding element 5a with a density of 1, 0 g / cm ³ and a thickness of 2 cm. As a result, a sufficiently stable cladding element 5a is already obtained, since the uniform distribution is maintained in the solidified state.

In order to increase the bond between the plastic particles 12 with one another and with the graphite particles 7, the mixture is additionally heated, so that the plastic particles 12 melt or even melt completely, then fuse together and connect with the graphite particles 7. In a cooling process, which can be done advantageously by active cooling or passive cooling of the mixture, the molten plastic particles 12 solidify while maintaining their molten shape, so that a uniformly dimensionally stable cladding element 5d is obtained, the uniform distribution is maintained in the solidified state.

The two steps mentioned above - pressing and heating - can advantageously also be carried out in succession. Alternatively or additionally, the solidification or compression can also be effected by curing and / or sintering. Also, these different types of consolidation can be combined.

Due to the inventive mixing of the graphite particles 7 and the plastic particles 12 to a mixture with substantially uniform distribution of the particles 7, 12 before solidification can be compared to the known graphite components advantageously uniform, dimensionally stable over its surface, rigid, robust and easy to handle paneling element 5a become.

A further embodiment according to the invention of a cladding element 5e shown in FIG. 6 differs from that shown in FIG. 5 by using the absorption layer 8 of the cladding element 5b shown in FIG. The embodiments and advantages described here apply analogously to the cladding element 5e from FIG. 6.

A further embodiment according to the invention of a cladding element 5f shown in FIG. 7, in addition to the embodiment of the cladding element 5e shown in FIG. 6, in the carrier layer 6, the phase change material 9 as the cladding element 5b of FIG. 3 and the conduit 10 of the cladding element 5c of FIG on. The properties and advantages of these supplements described for this also apply to the cladding element 5f.

Instead of the manufacturing process of the carrier layer 6 described with reference to FIG. 5, after mixing the graphite particles 7 and the plastic particles 12, the mixture can first be pre-consolidated such that it is still plastically deformable, and only then the conduit 10 into the still plastically deformable carrier layer 6 pressed and this or the mixture is subsequently solidified, as described above. Then, as described above, the absorption layer 8 is mounted on the carrier layer 6.

In addition, the cladding element 5f still has a plaster layer 13, which is preferably applied after the attachment of the cladding element 5f to the exterior facade and / or the roof of the building. Alternatively, however, the plaster layer 13 can already be applied during the production of the cladding element 5f. the. Advantageously, as an alternative or in addition, a facade paint can already be applied to the lining element 5f during production or even after the application of the plaster layer 13. Also, the absorption layer 8 can be omitted and the plaster layer 13 and / or a color layer can be applied directly to the support layer 6 of the cladding element 5f. In order to allow a good adhesion of the plaster and / or the color, the carrier layer 6 or the absorption layer 8 is prepared for receiving the plaster and / or the color, preferably roughened.

The cladding element according to the invention makes it easy to use external facades and / or roofs of buildings for the production of heat energy. So far, for example, energetically unused facade surfaces can be retrofitted by the easily manageable and dimensionally stable cladding elements. The use of phase change materials 9 in the carrier layer 6 can also be used to a more uniform utilization of the solar energy irradiated. For example, as the tempering of interiors of office buildings in usually cooler evening hours could be provided essentially by the registered throughout the day in the cladding elements heat energy, since the cooling of the building is delayed by this.

Thus, prefabricated cladding elements which are suitable for use as thermally acting solar modules can be produced, so that an industrial production of such cladding elements and their use in the construction sector can be carried out, whereby the price for such cladding elements can be significantly reduced. Due to the great dimensional stability and rigidity of such cladding elements, their handling and installation on facades of buildings considerably facilitates. In particular, dimensionally stable cladding elements can be produced and used with larger dimensions, without having to fear damage to the cladding elements during transport and handling.

Claims

claims

1 . Thermosolar cladding element (5a-f) for exterior facades and / or roofs of buildings with a graphite-containing carrier layer (6), characterized in that the carrier layer (6) has a density of at least 0.6 g / cm ³ , preferably at least 1.0 g / cm ³ .

2. Thermosolares cladding element (5d-f) for exterior facades and / or roofs of buildings with a graphite-containing carrier layer (6), in particular according to claim 1, characterized in that it comprises a solidified mixture of substantially uniformly distributed plastic particles (12) and graphite particles (7 ) contains.

3. cladding element (5a-f) according to claim 1 or 2, characterized in that the carrier layer (6) comprises compressed graphite expander (7), in particular graphite expander containing graphite particles (7).

4. cladding element (5d-f) according to claim 2 or 3, characterized in that the graphite particles (7) and plastic particles (12) are distributed homogeneously in the mixture.

5. cladding element (5d-f) according to one of claims 2 to 4, characterized

in that the mixture contains 5 to 90% by weight, preferably 15 to 60% by weight and particularly preferably 20 to 50% by weight of plastic particles (12).

6. cladding element (5d-f) according to one of claims 2 to 5, characterized

in that the plastic particles (12) contain thermoplastics and / or thermosets.

7. cladding element (5d-f) according to one of claims 2 to 6, characterized

in that the plastic particles (12) are polyvinyl chloride (PVC), polypropylene (PP), polyamides (PA), acrylonitrile-butadiene-styrene (ABS), polyethers clay (PEEK), polyvinylidene fluoride (PVDF), fluoropolymers, benzoxazines and / or polysulfone (PP).

8. cladding element (5d-f) according to one of claims 2 to 7, characterized

in that the plastic particles (12) contain epoxy resin, phenolic resin, melamine resin, urea resins, and / or polyester resins, in particular unsaturated polyester resins (UP resins).

9. cladding element (5d-f) according to one of claims 2 to 8, characterized

in that the carrier layer (6) consists exclusively of the mixture of graphite particles (7) and plastic particles (12).

10. cladding element (5b, f) according to one of the preceding, characterized in that the carrier layer (6) contains one or more phase change materials (9).

1 1. Cladding element (5b, f) according to claim 10, characterized in that the phase change material (9) is paraffin, preferably soft paraffin.

12. cladding element (5a-f) according to any one of the preceding claims, characterized in that the carrier layer (6) is at least 0.5 cm, preferably at least 1 cm thick.

13. cladding element (5c, f) according to any one of the preceding claims, characterized in that in the carrier layer (6) tubes or pipes (10) are embedded for the passage of a heat transfer fluid.

14. cladding element (5b, c, e, f) according to any one of the preceding claims, characterized in that on the side facing the solar radiation side of the carrier layer (6) an absorber layer (8) for converting solar radiation into heat is arranged.

15. cladding element (5c) according to any one of the preceding claims, characterized in that it on the solar radiation side facing, in particular on the carrier layer (6) or the absorber layer (8) a

Protective layer (1 1) has.

16. cladding element (5f) according to claim 14 or 15, characterized in that the cladding element (5f) on its side facing the sun, in particular on the carrier layer (6) or the absorber layer (8), for receiving plaster (13) and / or color pretreated, in particular roughened.

17. cladding element (5a-f) according to one of the preceding claims, characterized in that it is plastically deformable.

18. cladding element (5a-f) according to one of the preceding claims, characterized in that it is shaped in a predetermined contour.

19. Use of a cladding element (5a-f) according to any one of the preceding claims for the outer cladding of exterior facades and / or roofs of buildings.