WO2010029217A1

WO2010029217A1 - Building element

Info

Publication number: WO2010029217A1
Application number: PCT/FI2009/050722
Authority: WO
Inventors: Kari Lautso
Original assignee: Rautaruukki Oyj
Priority date: 2008-09-12
Filing date: 2009-09-09
Publication date: 2010-03-18
Also published as: FI20085860A; FI20085860A0; EP2334881A4; EP2334881A1; FI121675B

Abstract

The invention relates to a building element (1) comprising a first plate and a second plate (2, 4) made of metal and placed substantially apart from one another in an electrically and thermally isolated manner. In accordance with the invention, the first and the second plates (2, 4) are interconnected with one or more semiconductor elements (6, 8; 7, 9) so as to make the building element (1) a thermoelectric module.

Description

BUILDING ELEMENT

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a building element in accordance with the preamble of claim 1 , and particularly, to a building element comprising a first and a second plate made of metal and placed substantially electrically and thermally isolated apart from one another.

[0002] Attempts have been made to develop energy efficiency and heating/cooling solutions of buildings in various ways. Various heat pump applications that utilize a difference in temperature between indoor air and outdoor air are a solution that improves energy efficiency. Various applications utilizing the thermoelectric effect or the so-called Peltier effect constitute a solution of this kind utilizing the difference in temperature. The thermoelectric effect and the Peltier effect are commonly known, and consequently they are not explained in this application. In accordance with prior art, the thermoelectric effect and the Peltier effect have also been utilized in construction technology in various heating and cooling solutions. In these solutions, a complete Peltier module is mounted, for instance, on a building element or attached to a window structure. The Peltier module generates thermal and/or refrigeration energy in its electrodes, wherefrom it is transferred to structures of the building element, such as surface plates or window panes.

[0003] The above described arrangement has a problem that significant changes must be made in the standard manufacturing process of building elements in order for mounting a Peltier module. In addition, changes have to be made in the actual building element, and consequently the structure of the building element may change significantly and its properties may deteriorate in comparison with a corresponding building element without a Peltier module. The above facts make the manufacturing process of a building element complex and thus economically costly. Moreover, the heat-exchange surface provided by the prior art solutions is small, which means that heating or cooling of a room space by means thereof is not feasible in practice, but the cooling and heating effect is primarily directed to structures in connection with the Peltier module, such as plates and window panes.

BRIEF DESCRIPTION OF THE INVENTION

[0004] The object of the invention is thus to provide a building element, whereby the above problems will be solved. This is achieved with a building element in accordance with the characterizing part of claim 1 , which is characterized in that the first and the second plates are interconnected with one or more semiconductor elements in order to make the building element a thermoelectric element.

[0005] Preferred embodiments of the invention are disclosed in the dependent claims.

[0006] The invention is based on the fact that plates made of metal, such as surface plates of a sandwich panel, included in a building element or building panel are utilized for providing a thermoelectric module or a Peltier module. In accordance with the invention, metal plates of a building element that are electrically isolated from one another are interconnected by means of semiconductor elements so as to provide a thermoelectric module. It is further possible to connect to this thermoelectric module a current source such that the current generates a difference in temperature between the electrically isolated metal plates.

[0007] The method and the system of the invention have an advantage that significant changes need not be made in the building element for mounting a thermoelectric module or a Peltier module, but the building element may be utilized as such as a part of the thermoelectric module or Peltier module. Thus, there is no need to make significant changes in the manufacturing process of a building element, but these building elements may be produced in the same manufacturing process and advantageously in the same production line as other conventional building elements. Moreover, because the heat- transfer capacity of the metal plates of the building element is good, the heat transfer surface of the thermoelectric module or the Peltier module will be large, and heat transfer to a room space need not pass through a poorly heat conducting building plate, but heat transfer may take place directly through the metal plates of the building element alone. This further enables heating or cooling of even large spaces. Additionally, in that case the whole wall or another structure made of building elements will be able to serve throughout its surface as a heat transfer surface.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the following the invention will be described in greater detail in connection with preferred embodiments with reference to the attached drawings, in which Figure 1 shows an embodiment of a building element in accordance with the present invention,

Figure 2 shows a second embodiment of the building element in accordance with the present invention and

Figure 3 shows a third embodiment of the building element in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0009] Reference is made to Figure 1 which shows an embodiment of a building element 1 in accordance with the present invention. In this embodiment the building element 1 is an insulated building panel, such as a sandwich panel, which comprises a first surface plate 2 and a second surface plate 4 and an insulation material 16 between them. The surface plates 2, 4 are mounted such that they are electrically isolated from one another and advantageously also thermally isolated from one another. The surface plates 2, 4 are made of metal and advantageously they are made of sheet metal, such as sheet steel. Insulation material 10 is attached by gluing, for instance, to inner surfaces, i.e. those facing one another, of the surface plates 2, 4. However, it should be noted that there is not necessarily insulation material 10 between the plates 2, 4, but there may be simply an air gap or some other electrically insulating material between the plates 2, 4. In addition, the distance between the plates 2, 4 may vary in different applications. In other words, the present invention may be applied to any building element that comprises two metal plates that are electrically isolated and advantageously also thermally isolated from one another.

[0010] In accordance with the present invention the first and the second surface plates 2, 4 are interconnected with one or more semiconductor elements 6, 8. The semiconductor elements may be rods as in Figure 1 or bars, beams or pieces of some other shape or size, which are mounted between the first and the second surface plates 2, 4. In the semiconductor elements it is possible to use any semiconductor material, such as silica or germanium. In addition, the semiconductor elements may be pure semiconductors, doped materials containing one or more semiconductors or doped semiconductors. For instance, doped materials may be, for instance, metals doped with a semiconductor, the metals being other than those in the surface plates 2, 4. In the doped semiconductors the semiconductor material is doped with some other material so as to obtain desired properties or material structure. In addition, the semiconductor elements are provided to be either p-type or n-type semiconductors, depending on the application. One building element may include p-type semiconductor elements or n-type semiconductor elements, or alternatively, both p-type and n-type semiconductor elements.

[0011] In the solution of Figure 1 the semiconductor elements 6, 8 are inside the building element 1 such that they traverse the building element 1 and extend between the first and the second surface plates 2, 4. Semiconductor elements 6, 8 of this kind may be mounted in the building element 1 during its fabrication, for instance before or after fitting of the insulation material 10, or alternatively, after the fabrication of the building element 1 , whereby rod-like semiconductor elements 6, 8 may be inserted through the building element 1 such that they connect the first and the second surface plates 2, 4. There may be one or more semiconductor elements 6, 8 mounted inside the building element 1 , depending on the application and each particular need. In addition, all the semiconductor elements 6, 8 may be either p-type or n-type semiconductors, or alternatively, they comprise at least one n-type semiconductor element and at least one p-type semiconductor element.

[0012] Figure 2 shows a second embodiment for placing semiconductor elements 7, 9 in the building element 1. In this embodiment the semiconductor elements 7, 9 are placed on the lateral edges of the building element 1 as shown in Figure 2. In that case the semiconductor elements 7, 9 connect the surface plates 2, 4 to one another in one or more lateral edges. In other words, on at least one lateral edge of the building element 1 there is mounted one or more semiconductor elements 7, 9 such that it connects the first and the second plates 2, 4. The semiconductor elements 7, 9 mounted on the lateral edges of the building element 1 may all be either n-type or p-type semiconductors, or alternatively, on one lateral edge there may be one or more p-type semiconductor elements and on one lateral edge there may be one or more n-type semiconductor elements. In addition, in some cases on one edge there may be both n-type and p-type semiconductor elements. Even though Figure 2 shows that there are semiconductor elements 7, 9 on only two lateral edges of the building element 1 , it is possible to place semiconductor elements on all lateral edges of the building element 1. In a preferred embodiment, which is shown in Figure 2, the building element 1 comprises at least on two lateral edges thereof tongue-and-groove forms 12, 14 provided in the first and/or the second plate 2, 4 so as to connect the building element 1 to another similar building element. At least one of the tongue-and-groove forms 12, 14 may be furnished with at least one semiconductor element 7, 9. In that case the semiconductor elements 7, 9 will be concealed in the joint or gap between two adjacent building elements 1. In addition, these semiconductor elements 7, 9 mounted on the lateral edges may be common to the adjacent building elements 1 , when they connect the first and the second surface plates 2, 4 of both adjacent building elements 1. In this embodiment the semiconductor elements 7, 9 are advantageously placed to extend along the lateral edges or tongue- and groove forms 12, 14 of the building element 1 , and advantageously substantially throughout the length of the lateral edge or the tongue-and-groove form 12, 14. The semiconductor elements 7, 9 to be mounted on the lateral edges may be, for instance, thin plate-like or strip-like elements that are arranged to fit in the dimensions and shapes of the lateral edges or tongue-and- groove forms 12, 14.

[0013] By means of the connections between the surface plates 1 of the building element 1 and the semiconductor elements 6, 7, 8, 9 the building element 1 is rendered a thermoelectric module. In the thermoelectric module is generated an electric current or voltage when there is a difference in temperature between two different metals, or a metal and a semiconductor, because different metals or metals and semiconductors react differently to temperature differences. In the building element of the invention a thermoelectric module of this kind is produced, when the first and the second surface plates 2, 4 are at different temperatures while being connected to one another by means of semiconductor elements 6, 7, 8, 9. If the first and the second surface plates 2, 4 are only connected to one another using either n-type or p-type semiconductors, between the first and the second surface plate 2 there is generated a voltage difference, but if the first and the second surface plates 2, 4 are connected to one another using both n-type and p-type semiconductors there is produced a circuit, in which a current runs through the semiconductors. The voltage difference and the current are proportional to the temperature difference between the first and the second surface plates 2, 4. In other words, in accordance with the present invention, the first and the second surface plates 2, 4 serve as electrodes of the thermoelectric module. In other words, in the thermoelectric module it is possible to generate a voltage or an electric current by means of the temperature difference of the electrodes. [0014] The previous effect may be made inverse, when a current source is connected to the thermoelectric module. A module of this kind is commonly known as a Peltier module. In this Peltier module it is possible to provide a temperature difference between the electrodes, in the present invention between the surface plates 2, 4, by means of the current source. This temperature difference may be further utilized in accordance with the invention for heating or cooling of the building. In accordance with the above, in the present invention the actual building element is rendered a thermoelectric module or a Peltier module.

[0015] In order to provide heating or cooling in the building in accordance with the invention a current source (not shown) is connected to the building element 1 , the positive pole of the current source being connected to the first plate 2 and the negative pole to the second plate 4, and the first and the second plates 2, 4 are interconnected with one or more n-type or p-type semiconductor elements 6, 7, 8, 9 so as to form a Peltier module and to produce a temperature difference between the first and the second plates 2, 4. In the n-type semiconductor the electrons move in the opposite direction in relation to the electric current, i.e. in this case from the second plate 4 to the first plate 2. Hence, if the first and the second plates 2, 4 are interconnected using only n-type semiconductor elements 6, 8, the second plate 4 is cooled, when a difference in temperature is generated between the first and the second plates 2, 4. The same effect is provided by using only p-type semiconductor elements, whereby the gaps in the p-type semiconductor run in the direction of the current. If the coupling of the current source is changed such that the positive pole is connected to the second plate 4 and the negative pole to the first plate 2, the first plate 2 is cooled and the second plate 4 is heated. In other words, in connection with the current source it is possible to provide control means or a thermostat for changing the heating/cooling direction of the Peltier module and/or for changing the polarity of the current source and/or for adjusting the temperature difference or temperature between the first and the second plates 2, 4. In other words, the control means or the thermostat may be arranged to change the polarity of the current source and/or to adjust the current from the current source.

[0016] Figure 3 shows a second embodiment of the present invention. In this embodiment the first plate 2 of the building element 1 is divided into a first and a second plate sections 18, 20 that are electrically isolated from one another. To the building element 1 is further connected a current source the positive pole of which is connected to the first plate section 18 and the negative pole to the second plate section 20. The first plate section 18 is connected to the second plate 4 with one or more n-type semiconductor elements 8 and the second plate section 20 is connected to the second plate 4 with one or more p-type semiconductor elements 6 so as to form a Peltier module and to create a temperature difference between the plate sections 18, 20 of the first plate and the second plate 2, 4. In accordance with the above, also in this embodiment it is possible to connect control means or a thermostat in connection with the current source. The first plate 2 may be divided into plate sections 18, 20, for instance into two sections, either during manufacture of the building element 1 or thereafter. In that case it is further possible to place, for instance sealing material, such as sealing tape, between the plate sections 18, 20.

[0017] In the preceding embodiments the Peltier module was provided from one individual building element 1. In other words, the building element 1 constituted a separate Peltier module. However, it is possible to interconnect two or more building elements such that they together form the Peltier module. In a solution of this kind the first plate 2 of the building element 1 is arranged for being connected in an electrically isolated manner to the first plate of an adjacent similar building element. The second plate 4 of the building element 1 is further arranged for being connected in an electrically conductive manner to the second plate of the adjacent similar building element. In addition, the first and the second plates 2, 4 of the building element 1 are interconnected with one or more n-type semiconductor elements and the first and the second plates of the adjacent building element are interconnected with one or more p-type semiconductor elements. The positive pole of the current source is connected to the first plate 2 of the building element 1 and the negative pole of the current source is connected to the first plate of the adjacent building element so as to form a Peltier module and to create a temperature difference between the first and the second plates 2, 4 of the building elements. Thus, in this embodiment the interconnection of the first plates of the adjacent building elements in an electrically isolating manner corresponds to the division of the first plate 2 into two sections in Figure 3. In order to mount the adjacent building elements 1 such that the first plates 2 are interconnected in an electrically isolating manner may be implemented by placing a sealing at least in the first plate of the second building element. Alternatively, during mounting it is possi- ble to place a sealing in the joint of the adjacent building elements, which sealing prevents electrically conductive coupling between the first plates 2. In the same way, the second plates of the building elements may be formed and connected such that they constitute an electrically conductive coupling with one another.

[0018] In the preceding embodiments it should be noted that also the second plate 4 may alternatively be divided into two sections or the second plates of the adjacent building elements may be electrically isolated from one another, whereas the first plates are interconnected in an electrically conductive manner. In addition, the control means or the thermostat in connection with the current source may be employed in a desired manner in connection with all embodiments. Further, by means of the arrangement of Figure 3 it is possible to interconnect the building elements of an entire wall such that there will be provided a plurality of Peltier modules in series, which may be operated with one current source. In that case the first and the second surface plates of the adjacent building elements are connected alternately in an electrically conductive manner or in an electrically isolated manner to one another.

[0019] In the solution of the invention it is possible to use as a current source any current source that is connectable to a building element, advantageously a DC source. In an embodiment the current source is a solar panel (not shown), which is mounted on the building element's 1 first plate 2 constituting a front surface of the building element 1. By using a solar panel as the current source it is possible that each building element 1 or an assembly of two or more building elements provide an independently operating Peltier module.

[0020] The building element 1 may be further provided with one or more heat accumulators or heat stabilizers for temporary storage and release of thermal and/or refrigeration energy. The heat stabilizer may be an element, for instance, which has a high heat storage capacity. An alternative is to use phase exchange material in the heat stabilizer or the heat accumulator. In an advantageous solution the heat accumulator or the heat stabilizer is a plate- like part that is placed to have a heat transfer connection with the first and/or the second plate 2, 4. The plate-like part may be placed on the inside or outside of the first and/or the second plate 2, 4.

[0021] In the preceding embodiments the building element 1 is described as an insulated building panel or sandwich panel, but the building ele- ment may be any building element comprising a first plate and a second plate that are set electrically apart from one another.

[0022] It is apparent to a person skilled in the art that as technology advances the basic idea of the invention may be implemented in a variety of ways. Thus, the invention and the embodiments thereof are not limited to the above-described examples, but they may vary within the scope of the claims.

Claims

1. A building element (1) comprising a first and a second plate (2, 4) made of metal and placed substantially electrically and thermally isolated apart from one another, characterized in that the first and the second plates (2, 4) are interconnected with one or more semiconductor elements 6, 8; 7, 9) in order to make the building element (1) a thermoelectric element.

2. The building element (1) of claim ^ characterized in that the semiconductor elements include at least one p-type semiconductor (6; 7) and/or at least one n-type semiconductor (8;9).

3. The building element (1) of claim 1 or 2, characterized in that the semiconductor elements (6, 8; 7, 9) are placed inside the building element (1) between the first and the second plates (2, 4).

4. The building element (1) of claim 3, characterized in that the semiconductor elements (6, 8; 7, 9) are rods, bars or the like elements.

5. The building element of any one of the preceding claims 1 to 4, characterized in that at least one semiconductor element (7, 9) is placed on the lateral edge of the building element (1) such that it connects the first and the second plates (2, 4).

6. The building element (1) of claim 5, characterized in that the building element (1) comprises on at least two lateral edges thereof tongue-and-groove forms (12, 14) provided in the first and/or second plates (2, 4) so as to connect the building element (1) to another similar building element and that at least one of the tongue-and-groove forms (12, 14) is furnished with at least one semiconductor element (7, 9).

7. The building element (1) of claim 6, characterized in that the semiconductor elements (7, 9) extend along the tongue-and-groove forms (12, 14) substantially throughout the entire length of the tongue-and-groove form.

8. The building element (1) of any one of the preceding claims 1 to

7, characterized in that between the first and the second plates (2, 4) there is arranged insulation material (10) or an insulating air gap.

9. The building element (1) of any one of the preceding claims 1 to

8, characterized in that to the building element (1) is connected a current source whose positive pole is connected to the first plate (2) and the negative pole to the second plate (4) and that the first and the second plates (2, 4) are interconnected with one or more n-type or p-type semiconductor elements (6, 8; 7, 9) so as to provide a Peltier module and to create a difference in temperature between the first and the second plates (2, 4).

10. The building element (1) of any one of the preceding claims 1 to 8, c h a r a c t e r i z e d in that the first plate (2) of the building element (1) is divided into a first and a second plate sections (18, 20) that are electrically isolated from one another and that to the building element (1) is connected a current source whose positive pole is connected to the first plate section (18) and the negative pole to the second plate section (20) and that the first plate section (18) is connected to the second plate (4) with one or more n-type semiconductor elements (8; 9) and the second plate section (20) is connected to the second plate (4) with one or more p-type semiconductor elements (6; 7) so as to provide a Peltier module and to create a difference in temperature between the first and the second plates (2, 4).

11. The building element (1) of any one of the preceding claims 1 to 8, c h a r a c t e r i z e d in that the first plate (2) of the building element (1 ) is arranged for being connected in an electrically isolated manner to the first plate of an adjacent, similar building element, that the second plate (4) of the building element (1) is arranged for being connected in an electrically conductive manner to the second plate of an adjacent, similar building element, that the first and the second plates of the building element (1) are interconnected with one or more n-type semiconductor elements (6, 8; 7, 9), that the first and the second plates of the adjacent building element are interconnected with one or more p-type semiconductor elements and that the positive pole of the current source is connected to the first plate (2) of the building element (1) and the negative pole of the current source is connected to the first plate of the adjacent building element so as to provide a Peltier module and a difference in temperature between the first and the second plates (2, 4) of the building elements.

12. The building element (1) of any one of the preceding claims 9 to

11 , c h a r a c t e r i z e d in that the current source is a solar panel that is mounted on the building element's (1) first plate (2) constituting the front surface of the building element (1).

13. The building element (1) of any one of the preceding claims 9 to

12, c h a r a c t e r i z e d by further comprising control means or a thermostat communicating with the current source for changing the heating/cooling direc- tion of the Peltier module and/or for changing the polarity of the current source and/or for adjusting the temperature or temperature difference between the first and the second plates (2, 4).

14. The building element (1) of any one of the preceding claims 1 to 13, characterized by comprising a heat accumulator or a heat stabilizer for temporary storage and release of thermal and/or refrigeration energy.

15. The building element (1) of claim 14, characterized in that the heat accumulator or the heat stabilizer comprises phase exchange material.

16. The building element (1) of claim 14 or 15, characterized in that the heat accumulator or the heat stabilizer is a plate-like part that is placed to have a heat transfer connection with the first and/or the second plate (2, 4).

17. The building element (1) of any one of the preceding claims 1 to

16, characterized in that the building element (1) is an insulated building panel or a sandwich panel.

18. The building element (1) of any one of the preceding claims 1 to

17, characterized in that the semiconductor element (6, 8; 7, 9) is provided from a semiconductor or doped material containing semiconductor, or a doped semiconductor.

19. Use of a first and a second plate (2, 4) of a building element (1) placed apart from one another in an electrically and thermally isolating manner and serving as electrodes in a thermoelectric module and a Peltier module.