WO2014102424A1

WO2014102424A1 - Freeform panelling system with high energy efficiency

Info

Publication number: WO2014102424A1
Application number: PCT/ES2013/070906
Authority: WO
Inventors: Luís Alberto ALONSO PASTOR; César BEDOYA FRUTOS; Benito Lauret Aguirregabiria; Fernando Alonso Amo
Original assignee: Universidad Politécnica de Madrid
Priority date: 2012-12-27
Filing date: 2013-12-20
Publication date: 2014-07-03
Also published as: ES2398119A1; ES2398119B2

Abstract

The invention concerns a freeform panelling system with high energy efficiency comprising a plurality of panels (1) connected to each other by means of a connection (2). Each panel (1) comprises two enveloping sheets (3) and (4), one being an inner sheet (3) and the other an outer sheet (4), composed of an SiO₂-PMMA resin matrix reinforced with natural cellulose nanofibres and an intermediate vacuum chamber (5) of 1hPa, disposed between the inner sheet (3) and the outer sheet (4) and filled with a monolithic silica aerogel. The means for connecting the panels have an undercut (9) in two of the first contiguous edges (10, 11) of the panel in a first corner of the panel and a step (12) of a thickness equal to that of the undercut (9) in the two contiguous edges (13, 14) in the second corner opposite the first corner.

Description

TITLE

HIGH ENERGY EFFICIENCY AND FREE FORM PANELIZATION SYSTEM DESCRIPTION Field of the invention

The present invention is included within the field of sustainable architecture and engineering within the construction of buildings and more specifically refers to a panel system of high energy efficiency and free forms for the constitution of architectural facades.

Background of the invention

At present, the architectural avant-garde demands a constructive system for facades and enclosures that are light, free and continuous surface and that additionally offer high performance in terms of energy efficiency, but which in turn allow the passage of Natural light and its backlight. In addition to this demand from a technical and architectural design point of view, society is increasingly aware of the need to reduce environmental impacts and the urgency of making buildings in which we live and work more efficient.

In the first place, there is a growing demand for buildings with high energy efficiency due to the penalties that come from the breach of the commitments to sustainability, from the new lines of architectural thinking for which sustainability is an inescapable design factor and a Quality assurance, from promoters, who begin to understand that under this motto they can sell their products at a higher price (26% on average), to end users aware of the economic savings that energy efficiency entails.

Secondly, free forms have long since ceased to be a formal aesthetic challenge and have become a new way of research to solve the new technical conditions posed by bioclimatic and sustainable architecture. This statement is supported by the words of Frank Lloyd Wright in which he unites inescapably the function with the organic form and with the form of nature (free forms, fractal and complex geometers, continuous surfaces, etc.). The benefits offered by the free form in bioclimatic design and sustainability are several, among them we can highlight: the ease of orientation, the greater solar exposure of the surfaces, the adaptation to the action of the prevailing winds, a better enveloping relationship -conditioned volume, greater comfort and social benefits due to having aesthetically more "friendly" and "soft" spaces, etc. At present, it has been shown that passive bioclimatic design measures can lead to a reduction of the order of 30% of the annual energy consumption of a building.

Finally, the minimum thickness is an almost obligatory requirement when the transparency of a facade is sought, and a challenge when trying to obtain high energy efficiency in conjunction with high strengths and reduced weights, but also offers a series of benefits that justify the need to try to find facades of less and less thickness.

In order to achieve the specific characteristics that have just been detailed, a wide variety of insulation materials and construction systems, such as glazing with vacuum chamber, are currently used, but the use of this system does not end up being advantageous since the glass has of some physical properties, as far as support for load solicitations is concerned, quite small, being a fairly fragile material with the problems that this entails in its handling and, above all, its high rate of breakage during handling and installation, which means that the cost of using this material for this type of architectural systems with free form and continuous surface, sometimes, is not all that it should for such purposes.

As an alternative, reinforced resins can be used, which are usually lighter and stronger, but this material has the disadvantage that it does not offer an optimal balance between the level of insulation, translucency and, above all, versatility when defining complex shapes.

On the other hand, of all the transparent insulations that currently exist, only gases such as argon and krypton although they improve that balance and incorporate transparency (greater than 85%) into the system have the problem of handling and encapsulated, which is very complex. In addition, once they are "leaking" through the walls of the panel or double glazing, the insulation is lost, until at the end (after 30 or 50 years) the system does not have any level of insulation since The gas has leaked.

Finally, traditional double glazing systems often use "metal layers" for solar control. There are, in general, two different types of metallic layers: hard or pyrolytic layers, reflective glasses that provide significant sun protection available in different colors, neutral glass with high insulating and selective performance, with a very low U coefficient. Double glazing that have metallic layers for solar control have traditionally some problems with condensation or interstitial dirt in the chamber as well as overheating and possible breakage: that is, the problems that may arise, come from the possibility of occurrence important thermal breaks in the same piece. That is to say, that on one of these glasses the sun and the shadow impinge simultaneously which can cause tensions and contractions that lead to breakage.

Therefore, the need to design a high energy efficiency and free form panelization system has been detected, which is lightweight, of a minimum thickness, of a high degree of light transmission, which allows the design of shapes free for use in architectural projects.

This objective is achieved by means of the invention as defined in claim 1. Preferred embodiments of the invention are defined in the dependent claims.

Description of the invention

The present invention relates to a panel system of high energy efficiency and free forms, comprising a plurality of panels joined together by a series of joining means.

The panelization system object of the present invention has the particularity that each panel comprises two wrapping sheets, an inner sheet and another outer sheet formed from a matrix of Si0 ₂ -PMMA resin reinforced with nanofibers natural cellulose and an intermediate vacuum chamber of 1 hPa, arranged between the inner sheet and the outer sheet, and filled with a monolithic silica airgel.

With the described configuration of the panels that make up the panelization system, it is possible to minimize the thickness of the building enclosure, optimizing its energy efficiency by being a transparent system, which will confer two new added properties: on the one hand, the possibility of generate a "structural skin" or a "self-supporting" enclosure, and on the other, the possibility of designing architectural skins using free forms. Therefore, a greater use of the interior surface of the building will be achieved (approximately 8.33% using this new system), and also a lower consumption of materials and the use of lighter materials in its construction, which entails a lower ecological footprint and lower energy and money consumption in the construction phase, among others. Additionally, due to the mechanical qualities of the materials it incorporates, this panel system provides a minimum thickness and monocoque and semi-hull elements can be constructed.

On the other hand, the monolithic airgel is an easy-to-handle and encapsulated material, and by itself it only has a very high level of insulation that can last much more than 50 years. By implementing this insulation through the vacuum chamber, we achieve that this level of insulation improves much more, and although this vacuum chamber also lasts between 30 and 50 years, the airgel would maintain its qualities as insulation, surely, another 30 or 50 years more , so that the system would never be without a good level of isolation, or in the worst case that is when it no longer had its vacuum chamber.

The design of the "outer skin" formed by the panelization system object of the present invention is carried out by means of a CAD / CAM system that transmits the information of the 3D model in the free form already discretized and panelized to a multipoint forming machine No matrix (Multi Point Forming (MPF)) that gives you the desired geometry.

In a first aspect of the invention, the panel may comprise an ITO bath (6) (Indium Oxide doped with Tin) applied on certain areas of the outer sheet (4). More specifically, the ITO bath will be applied over transparent areas of the panel. Using the sol-gel technology, the ITO solution is obtained and the panel is immersed in it and by an ultraviolet or thermal treatment, the ITO solution reacts with the Si0 ₂ and a resistant film is generated that acts as a solar control element , being able to reduce the transmission of UV rays by almost 0%, and infrared by 10%. This limits the entry of radiant solar heat into the space delimited by the panelization system of the invention. Therefore, the use of an ITO bath or primer, avoids the obligation of having a "metal sheet", and offers more competitive features than many of the solar control systems used in construction today.

In another aspect of the invention each panel may comprise a layer of PMMA resin applied in situ on certain areas of the outer sheet. More specifically, the PMMA resin layer will be applied over the translucent areas of the panel. In this way, this "protection layer" made in situ, is more oriented to the translucent and also opaque areas of the panels that are part of the system, where the use of ITO is not necessary, because since it is not necessary a solar control, as these areas are translucent, but a good surface finish is essential. However, if necessary, the PMMA resin layer could be applied over the ITO bath or vice versa, this feature being optional and in no case limiting.

Each panel may comprise a final outer protective film selectable between an antistatic gel film based on polyester resin applied directly on the ITO bath, in the case of transparent areas, or a lacquer film, deposited on the layer of PMMA resin for translucent and opaque areas. This protective layer may be transparent in the case of being deposited on the ITO bath, or translucent in the case of being applied on the PMMA resin layer. With regard to the joining means between the panels, they may consist of arranging a recess in two of the first contiguous edges of each panel in a first corner of the panel and practicing a stepping of the same thickness as the recess in the two contiguous edges in the second corner opposed to the first corner, to define an overlapping tongue and groove joint between adjacent panels. To ensure the aforementioned joints, high thermoplastic screws may be used resistance through recesses and staggered adjacent panels. Finally, to provide the joint with a good surface finish and reduce the discontinuities that may occur between said joints between adjacent panels, said joints may be chemically sealed by industrial chloroform.

In another aspect of the invention, vacuum valves may be arranged located in the overlapping areas between adjacent panels, where said vacuum valves will have a plug of Si0 ₂ -PMMA screwed into holes made for this purpose in the panels. Said plugs shall also be chemically sealed by means of industrial chloroform and the corresponding protective film is applied thereto, as for the rest of the panel. The main mission of these vacuum valves is to achieve the vacuum in the panel. In the background are "drain valves"; that is, they are valves, similar to those of filling the tires of a car, but of inverse use. The emptying is done at the end of the entire manufacturing process of the panel. The emptying is individualized; panel by panel: Once the panel is mounted, and the airgel is encapsulated and dried inside, it is when the panel is emptied. With this in mind, emptying is done before joining between panels.

In a final aspect of the invention, it should be noted that the panels may be backlit. The backlight would be done by inserting a waterproof, adhesive, side emission strip on one side of the panel. The light color could be from White / Warm White Xenon White with the option to also use the colors: Green / Blue / Red. Brief description of the drawings

A series of drawings that help to better understand the invention and that expressly relate to an embodiment of said invention which is presented as a non-limiting example thereof is described very briefly below. Figure 1 represents a plan view of one of the panels that are part of the panelization system object of the present invention.

Figure 2 shows a perspective view of the panel of Figure 1.

Figure 3 shows a perspective view of the arrangement of two adjacent panels before joining in which the overlapping tongue and groove joint system of the panelization system object of the present invention is observed. Figure 4 shows a perspective view of a portion of an enclosure constituted by the panelization system object of the present invention.

Figure 5 shows a sectional view of the enclosure portion of Figure 4. In the aforementioned figures, a series of references are identified that correspond to the elements indicated below, without implying any limiting character:

1. panels

2. joining means between adjacent panels

3. Internal sheet of Si0 ₂ -PMMA resin matrix reinforced with natural cellulose fibers

4. external sheet of Si0 ₂ -PMMA resin matrix reinforced with natural cellulose fibers

5. intermediate vacuum chamber

6. ITO bathroom

7. PMMA resin layer

8. protective film

9. recess in first panel edges

10, 1 1. first contiguous edges of the panel in the first corner

12. stepping on second panel edges

13, 14. second panel edges in second corner

15. Thermoplastic screws for fixing adjacent panels

16. joints between adjacent panels

17. vacuum valves.

Detailed description of an embodiment of the invention

The high energy efficiency and free form panelization system comprises a plurality of panels 1, one of which has been represented in isolation in Figures 1 and 2. Specifically in Figure 1 a plan view of the panel has been represented 1 and in figure 2 the same panel in perspective.

Each panel 1 comprises two enveloping sheets 3 and 4, an internal sheet 3, which will remain inside the enclosure determined by the panels 1 and another external sheet 4, which will remain outside said enclosure, both constituted from a Si0 ₂ -PMMA resin matrix reinforced with natural cellulose nanofibers and an intermediate vacuum chamber 5 of 1 hPa, arranged between the inner sheet 3 and the outer sheet 4, and filled with a monolithic silica airgel. Different surface treatments will be applied to the outer surface of the outer sheet 4 and depending on whether it is opaque or transparent areas.

The monolithic airgel, being the most expensive and difficult to produce is the most conditioning factor in terms of size and final measures that panel 1 will have. Based on the long drying times of the Sol-gel process you need the monolithic silica airgel to generate its crystalline structure, the percentage of pieces that are broken due to the size (round 1% of the production), and especially that today there are only autoclaves that allow generating monolithic airgel parts of 550 mm x 550 mm, which is why the panel dimensions will be 600 mm x 600 mm (side / width) and the thickness will depend on whether it is a monocoque structure or a simple enclosure, and the needs of transparency and thermal-acoustic insulation For the modeling of the system, a 35 mm thick panel has been studied, consisting of two 2.5 mm thick sheets of Si0 ₂ -PMMA reinforced with cellulose nanofibers and a 25 mm thick vacuum chamber, filled with monolithic silica airgel, as seen in Figure 5.

A weight per unit area of between 15 and 7 kg / m ² is assumed. The prototype modeled for the tests offers a weight within that fork of weights since its weight is 8, 1 1 kg / m ² , and the density of the panel is 232.05 Kg / m ³ . The width and height of the panel shall not exceed 600 mm x 600 mm (although the dimensions may be smaller) and the minimum allowable bending radius is approximately 4,000 mm. The test prototype has dimensions of 600 mm x 600 mm x 35 mm, a volume of 0.0126 m ³ and a weight of 2.92 kg. If filled with airgel, approximately 10 liters of this material are consumed. In the case of transparent areas, an ITO 6 bath will be applied which is an excellent material for the solar control of the system, on the contrary in translucent and opaque areas a layer of PMMA 7 resin will be applied. In the case of transparent areas apply a last protective film 8 of antistatic gel based on polyester resin, which will be transparent and in the case of translucent areas and opaque a last protective lacquer film 8 will be applied, which will be translucent or opaque.

In this specific embodiment, the panel 1 will have a recess 9 in each of the first two adjacent edges 10 and 1 1 of the panel in a first corner of the panel and in the same way the panel 1 will have a stepping 12 of the same thickness as the recess 9 on each of the two adjacent edges 13 and 14 in a second corner opposite or opposite the first corner. Therefore, each panel has two edges that generate the opposite corners, two of them are "male edges" 13 and 14 and the other two are "female edges" 10 and 1 1. This facilitates the locking and assembly of the entire system in work. The joint consists of the following dimensions: male and female edges: 40mm overlap, over the entire length of the overlap (approximately 600mm). The thickness of these overlapping surfaces (or ears) is 17.5 mm, the sum of which offers 30 mm of panel thickness, which offers continuity to the system. There are two walls of 2.5 mm of the thickness of the skin in the fold of the overlap and 10 mm of vacuum chamber with monolithic airgel core. When superimposing the panels in the assembly, the joint consists of 30mm thick, like the rest of the system, but its composition will be that of four 2.5mm thick walls of reinforced resin, and two vacuum chambers filled with gel 10 mm monolithic silica.

This very special form of panel 1 is due to providing it with simple joining means that make the surface defined by the panels 1 when joining as continuous as possible. In fact, the panel 1 has a composite shape formed from two diagonally overlapping square shapes as can be seen in the aforementioned figures 1 and 2, where the recess 9 is overlapped with the corresponding stepping 12 of the adjacent panel 1.

In Figures 4 and 5 it can be seen more precisely how two adjacent panels are joined. To secure the joints between adjacent panels, high-strength thermoplastic screws 15 will be used that pass through recesses 9 and steps 12 of adjacent panels. Three thermoplastic screws will be used, each of approximately 52 mm, which will be responsible for securing the system in the construction site. This assembly between panels 1 is consolidated by the application to the joints 16 between panels 1 of industrial chloroform that thanks to its chemical welding does not leave space between the panels, being able to be designed with millimeter accuracy for its assembly and also seals the system hygroscopically .

The system will be completed with vacuum valves 17 located in the overlapping areas between adjacent panels, close to the screwed-in areas between panels 1, said vacuum valves 17 having a plug of Si0 ₂ -PMMA screwed into holes made for this purpose. in the panels 1, said cap also being chemically sealed by the industrial chloroform and finishing the surface finish with a protective film 8 of antistatic gel-coat.

To achieve the backlight of the panels, an LED strip (not shown in the figures) will be used. This LED strip will be waterproof and self-adhesive and will have 15 LEDs (Side SMD) of high lateral emission intensity and total length of 30 cm. In addition, it will have a 12V connection cable at both ends and 55 cm long X 5mm wide X 2mm high, which can be connected directly between the panels generating a continuous circuit until reaching the power supply or a plug.

This backlight could be integrated inside the panel in the manufacturing process: The moment would be when the panel is being assembled and the "box" is already built, this element would adhere to one side of it in the inner face. Both ends would be allowed to pass through the panel walls, and the perforations would be sealed by acrylic resin. By leaving the two terminations with a "contact surface, or connection" outside, the panels, when assembled, would generate LED lines that would end up in the building's power supplies (through a conventional installation) and in the control system of LEDs Once the passage of the two endings was sealed, the panel filling and drying process would be similar to the one already proposed.

Another option, taking into account the low thickness of the LED strip (2mm), would be to place the strip, externally, within the joint between panels. This would greatly reduce the installation and simplify the manufacturing process, eliminating perforations in the panel.

Claims

1. High energy efficiency and free form panelization system comprising a plurality of panels (1) joined together by means of joining (2) characterized in that each panel (1) comprises:

1.1 two sheets (3) and (4) envelopes, an inner sheet (3) and another outer sheet (4) formed from a resin matrix of SÍ02-PMMA reinforced with natural cellulose nanofibers;

1.2 an intermediate vacuum chamber (5) of 1 hPa, arranged between the inner sheet (3) and the outer sheet (4), filled with a monolithic silica airgel.

2. Panel system of high energy efficiency and free forms according to claim 1, characterized in that the panel (1) comprises an ITO bath (6) (Indium Oxide doped with Tin) applied on certain areas of the outer sheet ( 4).

3. Panelization system according to claim 2, characterized in that the ITO bath (6) is applied on transparent areas of the panel (1).

4. Paneling system according to the preceding claims, characterized in that the panel (1) comprises a layer of PMMA resin (7) applied in situ on certain areas of the outer sheet (4).

5. Panelization system according to claim 4, characterized in that the PMMA resin layer (7) is applied on the translucent areas of the panel (1).

6. Paneling system according to the preceding claims, characterized in that each panel (1) comprises a last outer protective film (8) selected from an antistatic gel film based on polyester resin or a lacquer film.

7. Panelization system according to claim 6, characterized in that the protective film (8) is transparent and is applied on the ITO bath (6).

8. Panelization system according to claim 6, characterized in that the protective film (8) is translucent and is applied on the PMMA resin layer (7).

9. Paneling system according to any of the preceding claims characterized in that the joining means between panels have a recess (9) in two of the first contiguous edges (10, 11) of the panel in a first corner of the panel and a stepping ( 12) of the same thickness as the recess (9) in the two adjacent edges (13, 14) in the second corner opposed to the first corner, to define a tongue and groove joint of adjacent panels (1).

10. Panelization system according to any of the preceding claims characterized in that the adjacent panels are fixed together by means of high-strength thermoplastic screws (15) that pass through recesses (9) and stepping (12) of adjacent panels.

1 1. Paneling system according to any of the preceding claims characterized in that the joints (16) existing between adjacent panels are chemically sealed by industrial chloroform.

12. Paneling system according to any of the preceding claims characterized in that vacuum valves (17) are located in the overlapping areas between adjacent panels, where said vacuum valves (17) have a plug of SÍ02-PMMA screwed into holes practiced for this purpose in the panels (1).

13. Panelization system according to any of the preceding claims characterized in that the panels (1) are backlit.