DE102012105743A1 - Heat shielding device with thermoelectric energy use - Google Patents

Abstract

Device for heat shielding comprising at least one sheet-like flat element which has a surface to be turned towards a heat-emitting heating device and a surface to be turned away from the heat-emitting device, a circuit of thermoelectric generators or a thermoelectric generator arrangement then being arranged at least in some areas and and a surface course of the planar element is formed in particular following a curvature, a crowning or a radius.

Description

The invention relates to a device for shielding heat with a device for generating energy by thermoelectric energy conversion.

Heat shielding elements are known. In particular, in the field of powered by internal combustion engines motor vehicles, these are used to protect in increasingly limited space in vehicles in particular attachments of engines against radiated heat, for example, exhaust manifolds or turbochargers. Such shielding plates are single-layer or multi-layered sheets made of sheet steel or aluminum, which may also be partially filled with insulating material in several layers.

Elements for thermoelectric conversion are also known by the abbreviation TEG (thermo electric generator). From the EP 1 976 034 A2 For example, a method for producing the individual elements and a thermoelectric generator thereof is known.

From the WO 2010/106156 A2 a thermoelectric device is known, wherein the thermoelectric device or a plurality thereof is arranged in a thermoelectric generator, wherein these are arranged through the exhaust gas of an internal combustion engine successively.

From the DE 102 31 445 A1 a thermoelectric element and a method for producing the same is known, wherein the thermoelectric element has a total layer stack comprising a first layer stack with a first electrically insulating carrier layer and a first electrically conductive functional layer and a second layer stack arranged thereon with a second electrically insulating carrier layer and a second electrically conductive functional layer and an electrically conductive connection layer, which electrically couples the first functional layer to the second functional layer on at least one side surface of the overall layer stack, wherein the first functional layer and the second functional layer form a thermocouple.

From the EP 2,131,406 A1 a method for producing a thermoelectric generator is also known, in which case also n-coupled and p-doped small columns are interconnected as thermoelectric generators.

From the DE 10 2008 005 694 A1 is also known a method for producing a thermoelectric device, wherein at least one thermoelectric pair of legs is present, which has an n-leg and a p-leg, wherein both legs are welded to an electrically conductive contact material, wherein the n-leg and the p Leg of the leg pair are welded in separate welding steps with the contact material, and a thermoelectric device.

From the DE 10 2010 031 829 A1 Thermoelectric devices are known with thin layers, in which case a substrate and a layer arrangement are present, which is formed on the substrate, wherein the layer arrangement has a planar base electrode a flat top electrode, planar p-doped regions and area n-doped regions which between the base and the cover electrode are arranged side by side and are alternately connected electrically in series, and a passivation structure, which is in each case formed in a planar manner between adjacent p-doped and n-doped regions and is designed to be electrically and thermally insulating.

This device is said to have some flexibility due to the flexible substrate.

From the DE 10 2006 055 120 A1 thermoelectric elements, processes for their preparation and their use are known, wherein the thermoelectric elements are produced in a porous matrix or a porous substrate and the matrix is to consist of an electrically insulating sufficiently thermally and chemically resistant material with the lowest possible thermal conductivity.

From the DE 10 2008 042 592 A1 a thermoelectric generator and a manufacturing method is known, wherein the thermoelectric generator has at least one in dependence on a temperature difference an electrical voltage generating thermocouple and a first and a second polymer substrate, wherein the thermocouples are arranged between the polymer substrates.

From the DE 10 2008 038 985 A1 For example, a thermoelectric device is known which comprises a first metal foil having a first material thickness, a second metal foil having a second material thickness a gap between the first metal foil and the second metal foil, an electrical insulation coating on the first metal foil and the second metal foil towards the gap, and one Plurality of first semiconductor particles and second semiconductor particles fixed in the space on the insulation coating and alternately electrically connected to each other. The metal foil should in particular be a very thin metallic wall for the thermoelectric device, so that the heat transfer or heat input to the semiconductor particles is particularly favorable.

From the EP 2 019 438 A2 is also known a thermoelectric element which is to be fabric-like.

From the US 2010/0269879 A1 is also known a thermoelectric module.

From the WO 03/007391 A1 is a thermoelectric module with thin film substrates known, said thermoelectric module is said to be flexible with a pair of flexible substrates and a plurality of electrically conductive contacts on one side of each of the flexible substrates and a plurality of p and n-type thermoelectric elements, the electrically are interconnected, wherein the p- and n-type elements are connected in known per se in series. The respective continuous substrate should be so flexible that the overall composite is slidable or flexible without, however, is specified as to how this should be realized.

The object of the invention is to provide a Wärmeabschirmelement or a device for shielding heat, which has at least partially a thermoelectric generator between at least two outer the Wärmeabschirmelement defining sheets.

The object is achieved with a device having the features of claim 1.

Advantageous developments are characterized in the subclaims.

According to the invention, a shielding device with a between at least two outer, the shielding plate defining and delimiting sheets, a cavity is formed in which a circuit of thermoelectric generators or a thermoelectric generator arrangement is present. According to the invention, thermoelectric generators or an arrangement thereof are chosen, which allows a high flexibility and formability. Since such heat shields, in particular in motor vehicles driven by internal combustion engines, are usually arched, cambered or otherwise not only two-dimensional in shape, it is necessary to adapt the thermoelectric generators to this shape or to adopt this shape, in particular during installation.

In this case, for example, the thermoelectric generators may initially be designed and installed in a planar manner, and then a common deformation with the heat shielding element may take place.

The invention is explained by way of example with reference to a drawing, show it

1 exemplifies the structure of a thermoelectric generator;

2 a first embodiment of the construction of a thermoelectric generator;

3 possible connector variants of the structure according to 2 ;

4 three different variants of the arrangement of a thermoelectric generator according to 2 ;

5 Another possible arrangement of the thermoelectric generator after 2 ;

6 to 9 different phases in the production of an inventively embossed thermoelectric generator;

10 to 12 another manufacturing method for a thermoelectric generator according to the invention;

13 to 16 a further embodiment of a thermoelectric generator and its preparation according to the invention;

17 to 20 another embodiment and another method for producing the thermoelectric generator according to the invention;

21 the overlapping areas in thermoelectric generators according to 10 to 12 . 13 to 16 and 17 to 20 ;

22 the connection after 20 with an electrically conductive connection layer.

The basic structure of a thermoelectric generator is simplified in 1 shown. Such a thermoelectric generator 1 has a hot side A and a cold side B.

The thermoelectric generator is delimited both on the hot side A and on the cold side B by a respective substrate two. Within the substrates are necessary for operating the thermoelectric generator so-called thermo legs 3 . 4 arranged. Here are the thermo legs 3 . 4 Semiconductor elements, for example, formed like a column, wherein each of the thermo legs 3 for example, a p-type semiconductor is and each of the thermo legs is an n-doped semiconductor. These thermo legs are with respect to their longitudinal extent transverse to the longitudinal extent of the substrates 2 arranged and thus arranged parallel to each other, wherein p- and n-doped semiconductor or thermo legs 3 . 4 alternating, arranged alternately. Two ends each of adjacent thermo legs 3 . 4 are about fasteners 5 electrically connected to each other. The connecting elements are designed alternately such that each thermo leg on one end face 3a with the adjacent thermo leg on the front side 3a is connected and with the opposite end face 3b with the first-mentioned thermo leg opposite thermo legs. To one on the inside of the substrates 2 facing side of the connecting elements is an electrical insulation layer 6 arranged, which electrically isolates the substrates against the connecting elements, wherein between the connecting elements and the insulating layer depending on a solder layer 7 is available for attachment. Between the electrical insulation layers 6 and the respective thermo thighs 3 . 4 can be any kind of matrix 8th z. B. be made of plastic foams.

In one embodiment of the invention ( 2 . 3 ) are the thermo leg ( 3 . 4 ) connected in the manner of a chain, wherein in the region of free ends 9 the thermo leg 3 . 4 end connector 10 are present, these end connectors 10 accordingly also the 1 alternating at the free ends 9 the thermo leg are arranged. Here, the end connector 10 for example, be made of metal sheets such as copper sheets, these metal sheets preferably more preferably form-fitting with a slight interference fit on the free ends 9 the thermo leg 3 . 4 are arranged so that a mobility around the longitudinal axis of each thermo leg 3 . 4 consists. Of course, this is only possible if the peripheral shape of the thermo leg 3 . 4 (in 2 circular) with recesses 11 in the end connector matches. Are the thermo legs 3 . 4 angular, it also offers the recess 11 according to the angular shape ( 3 ). The end connectors 10 are particularly coated with barrier layers to prevent metal ions in the doped material of the thermocouple 3 . 4 can diffuse or reverse. A suitable barrier layer is, for example, a nickel coating.

In 2 it can be seen that a bend of the entire chain arrangement in each case about the transverse axis of the connecting elements 10 is possible. Of course, a bend or curvature about the longitudinal axes of the legs is possible because a deformability, however, about the transverse axis of the connecting elements 10 is necessary to achieve an adaptation to a curvature of the shielding plate, the leeway that the chain arrangement has for this, is crucial. To the flexibility or mobility in this corresponding direction, ie to the transverse axes of the connector elements 10 To allow or improve, it may be useful to an entanglement of the chain assembly about the longitudinal axis of the thermal leg 3 . 4 make. Such entanglement possibilities are in 4 shown, with the lines in this figure, the simplified end connector 10 and the points, the thighs 3 . 4 represent. Due to such Entschränkungen it comes with bending on the pressure side not to the end connector 10 touching with end faces, which would cause a short circuit. In order to allow a bend for the purpose of radii tracing in the cavity of a shielding element in an additional axis can in the end connectors 10 additional Sollknickstellen be present, which allow this bend.

To fill the cavity in a Wärmeabgleitblech, the corresponding thermoelectric generators or the chain according to the arrangement in 5 be laid within the cavity, wherein the chain is placed in loops and thus at the ends of the entire chain is connected. In 5 the chain is shown considerably shortened for this purpose, of course, according to the expansion of the cavity, a plurality of in 5 shown arrangements according to a) in the 4 , but also b) or c) or any other staggered or entangled arrangement possible and useful.

In a bend of the chain assembly about the transverse axes of the end connector 10 or connecting elements 10 This prevents the end connectors from touching each other. In order to achieve additional fixation between the individual rows of chains, the rows of chains can be spaced apart with spacer elements such as foam strips or the like, or be inserted into a corresponding matrix.

In a further advantageous embodiment ( 7 to 9 ), the thermo legs are not columnar, but step-like platelet-shaped, the thermo-legs accordingly 6 can be first punched and formed from an elongated p- or n-doped semiconductor plate when needed in the heated state, wherein the shaping can be done deviating in casting, powder injection molding or similar processes that produce a thin layer. If the shaping and stamping takes place from a semiconductor sheet or a semiconductor foil, a residual grid remains, with which the corresponding thermo legs can be positioned ( 7 ), each with a free end 15 of the n- or p-doped leg 16 . 17 lie flat on each other. These surfaces are then soldered or glued together, wherein in these areas still separating layers may be present to a diffusion of the doping elements in the other of the other thermo legs 16 . 17 to prevent. In particular, this may be a thin nickel coating.

After the elements have been stacked and joined together in this way, the remaining grids become frames 18 separated and it remains in step-step alternately the thermoelectric generator assembly according to 9 which are on a substrate 19 is arranged. Such an arrangement can be adapted according to a corresponding curvature due to this corresponding shape and an existing residual flexibility of the individual stair-step-like elements.

Alternatively, a corresponding curvature can be realized already during the forming.

However, such an arrangement can not be laid in loops, so that in such an arrangement rows accordingly 9 insulated from each other with interleaves are laid in the cavity of the shielding plate and the ends are alternately electrically connected to achieve a series connection.

In particular, this arrangement may also be between two substrates 19 be arranged, which abut in principle the same as in the first embodiment of the thermoelectric elements or generators and are accordingly insulated. Also in this case, in the cavities that results between the substrates, a matrix 8th to be available.

In a further advantageous embodiment ( 10 to 12 ), the p-type and n-type doped regions are formed by respective 3D printing processes as in particular L-shaped elements 20 on a corresponding substrate 21 printed. This z. B. first, the n-doped regions 20 on the substrate 21 printed and then the p-doped regions 22 ( 11 ). The corresponding L-shaped areas 20 . 22 are alternately arranged such that always one end face 23 a long L-leg on a short L-thigh 24 of the adjacent element 20 . 22 is applied. Again, electrically conductive barrier layers can be realized. If it is useful and necessary due to the material used for the thermal leg, sintering of the printed materials then takes place over z. B. laser sintering or after the further processing described below in the installed state completely z. B. in an oven. For some procedures, e.g. B. inject pressure sintering may be omitted if necessary. Subsequently, the thus printed film upright or relative to the substrate 21 be placed upright and rolled up or are also inserted in tracks in the corresponding cavity of the shielding. It is also possible that the film or the substrate 21 in Hochkanter orientation already has a curvature or a radius or a bend that corresponds to the installation situation, which already in the printing process, this film or substrate 21 is printed accordingly, so that there is a high flexibility in terms of shaping.

In a further advantageous embodiment is also on a preferably sheet-like substrate 30 the corresponding structure of L-shaped n-doped and p-doped regions 31 . 32 with a sputtering method, e.g. B. a PVD process deposited. The L-shaped regions hereby correspond approximately to the regions from the previously described embodiment, wherein the substrate is first pretreated for deposition in such a way that the substrate is formed with an insulating mask which leaves the regions to be coated ( 17 ). Then, a thermoelectric layer is masked, with a corresponding further mask 34 is used, which leaves free the region of a first thermoelectric layer, and then exchanges the mask, so that the masking corresponds to the second thermoelectric layer and then sputtering the second thermoelectric layer and then removing the mask, so that the corresponding L-shaped regions 31 . 32 on the substrate 30 available ( 19 ). Also this substrate 30 can then be turned upright and rolled up and installed accordingly, with both the printing and sputtering course corresponding curvatures are needed to follow the curvature of a cavity in a shield, can be considered when cutting the substrate and accordingly the mask and thus the sputtering result can be adapted to the curvature.

In a further advantageous embodiment ( 13 to 16 ), a laser sintering method is used instead of a printing or sputtering method. For this purpose, first, as in the other methods, a substrate 40 provided. On this substrate 40 becomes a first powder layer 41 applied and this first powder layer 41 subsequently in the areas where L-shaped doped legs 42 ( 14 ) are to be formed, sintered by means of a laser beam. Subsequently, the residual powder is removed, for example by blowing off. Subsequently, the second thermoelectric Material as a second layer of powder 43 applied and then laser sintered so that the second L-shaped areas 44 arise, which in turn are arranged in the manner already described at the other L-shaped areas. Also, this substrate can then be placed edgewise, which of course also in this process with the cutting of the substrate 40 and the corresponding adaptation of the shape of the laser-sintered elements 42 . 44 can be entered on curvatures. When the thermoelectric elements are rather brittle, winding is not necessarily required or possible, but the substrates are laid in series, with the back side 45 a substrate also on the elements 42 . 44 rests and these against each other or the rows isolated from each other. As a result, as in the other methods, a favorable high packing density can be achieved. The corresponding row ends are then again alternately electrically connected to each other to bring about a series connection.

In a further advantageous embodiment (not shown) is according to the 13 to 16 the thermoelectric material is not applied in powder form, but in the form of a cast film or a Foliengießverfahrens and then laser sintered and then passes through another Foliengießschritt in which the other material is applied and laser sintered. Remaining material is also removed and can be reused.

In a further advantageous embodiment (not shown), the L-shaped elements are produced in a film casting process and subsequently the film is cut in an L-shaped manner. This can be followed by two different processes. Either the L-shaped elements are placed on the substrate, wherein the substrate or the L-shaped elements are formed with appropriate adhesion promoters so that when laying, rolling and then peeling off the film only the L-shaped elements remain on the substrate. This is repeated in the same way with the L-shaped elements of the other doping state in a corresponding geometric arrangement so that also results in the desired alternating sequence of L-shaped elements with contact each other.

In order to increase the contact area, it is possible to overlap the L-shaped elements ( 20 . 21 ) in which both the laser sintering method with powder, but also by means of film process, the corresponding contact surfaces of the first applied elements are provided with a step, so that the material of the other doped material can be applied overlapping in these step-shaped areas, wherein between the two materials p and n a barrier layer 50 may be present, which is also printed, sputtered or applied in any other way.

Instead of L-shaped n- and p-doped regions or thermo legs, these can also be flat rectangular, d. H. be formed without short L-leg, these flat rectangular, or täffel- or rod-shaped elements are arranged angled to each other and abut each other in the region of their free ends or overlapping each other, with adjacent such formed plate, sheet or rod-shaped elements a preferably include acute angles with each other. Incidentally, such elements can be prepared in the same manner as described above in the same way as the L-shaped elements.

In addition, these thin films can be produced not only with the methods described above but it can also z. B. partially overlaid thin films are prepared by first a corresponding matrix of a foam material, in particular rigid foam material cut or framed accordingly and then the thin films are created with alternating doping in this matrix. In this case, in turn, first thin films of a first doping and then thin films of a second doping were generated, wherein the regions of the respective other doping are first masked. In this case, in particular, a method may also be used in which these areas grow up as crystalline layers or can be deposited.

In the invention it is advantageous that in an effective and automatable manner thermoelectric generators are generated, which can be used in Wärmeabschirmblechen, wherein the heat shields have a cavity which receives a pack of these thermoelectric generators. In this case, the corresponding generator arrangements can be adapted in a simple manner to corresponding curvatures.

In order to increase the thermoelectric efficiency, the Wärmeleitbleche may have on their cold side additional means for bringing or accelerating a cooling flow from the ambient space to increase the temperature difference between hot and cold side.

LIST OF REFERENCE NUMBERS

2

substrates

3

Thermo leg

3a

front

3b

front

4

Thermo leg

6

insulation layer

7

solder layer

8th

matrix

9

free ends

10

end connector

15

free end

16

Thermo leg

17

Thermo leg

18

frame

19

substratum

20

elements

21

substratum

22

Area

23

front

24

L-leg

30

substratum

31

n-doped region

32

p-doped region

40

Substrate / matrix

41

powder layer

42

L-shaped doped leg

43

powder layer

44

L-shaped area

45

back

50

junction

A

hot side

B

cold side

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1976034 A2 [0003]
• WO 2010/106156 A2 [0004]
• DE 10231445 A1 [0005]
• EP 2131406 A1 [0006]
• DE 102008005694 A1 [0007]
• DE 102010031829 A1 [0008]
• DE 102006055120 A1 [0010]
• DE 102008042592 A1 [0011]
• DE 102008038985 A1 [0012]
• EP 2019438 A2 [0013]
• US 2010/0269879 A1 [0014]
• WO 03/007391 A1 [0015]

Claims (19)

 Apparatus for heat shielding comprising at least one sheet-like sheet-like element which has a surface to be turned away from a heat-emitting device and a surface to be turned away from the heat-emitting device, at least partially a circuit of thermoelectric generators or a thermoelectric generator arrangement then being arranged at least one surface of the device, and a surface profile of the sheet-like element, in particular a curvature, a crown or a radius is formed following. Apparatus according to claim 1, characterized in that at least two sheet-like planar elements are present, wherein the elements delimit between each two facing surfaces a cavity which is partially closed or completely closed, in which the thermoelectric generators and the thermoelectric generator assembly is received. Device according to one of the preceding claims, characterized in that the thermoelectric generator assembly is flexible or formable in itself, in order to be adaptable to a surface profile or made shaped according to the surface. Device according to one of the preceding claims, characterized in that the thermoelectric generator arrangement of at least one pair of thermal legs 3 . 4 is formed, of which a thermo leg ( 3 ) an n-doped semiconductor and the other thermo leg ( 4 ) is a p-doped semiconductor, wherein the n-doped and the p-doped thermo leg ( 3 . 4 ) is electrically connected at one end. Device according to one of the preceding claims, characterized in that the thermo legs ( 3 . 4 ) are connected together in the manner of a chain, wherein in the region of free ends ( 9 ) of the thermo leg ( 3 . 4 ) End connector ( 10 ) are present, these end connectors alternately at the free ends ( 9 ) of the thermo leg ( 3 . 4 ) are arranged so that the thermo leg ( 3 . 4 ) are connected in series. Apparatus according to claim 5, characterized in that the arrangement of the thermo leg ( 3 . 4 ) is inserted in the manner of a chain in a flexible matrix, in particular a matrix of foam or the like. Device according to one of the preceding claims, characterized in that the end connectors ( 10 ) are made of metal sheets such as copper sheets, copper-plated or nickel-plated sheets. Device according to claim 7, characterized in that the metal sheets ( 10 ) or with a slight interference fit on the free ends ( 9 ) of the thermo leg ( 3 . 4 ) are arranged. Apparatus according to claim 7 or 8, characterized in that the cross-section, the circular thermo legs ( 3 . 4 ) the end connectors ( 10 ) are arranged so that a mobility about the longitudinal axis of each thermo leg ( 3 . 4 ) consists. Device according to one of the preceding claims, characterized in that an array of thermal legs ( 3 . 4 ) and end connectors ( 10 ) is arranged in rows or loops in the cavity of the device, that about the longitudinal axis of the thermo leg ( 3 . 4 ) an entanglement is present such that when bending about the transverse axis of the end connector ( 10 ) the thermo legs which are connected by the end connector, without being touched, are pivotable. Device according to one of claims 1 to 4, characterized in that the thermo leg ( 3 . 4 ) step-like platelet-shaped, wherein the thermo leg of a semiconductor sheet or a semiconductor foil, which has the corresponding doping punched out and deformed, in particular thermoformed, wherein in each case a free end ( 15 ) of the n- or p-doped leg ( 16 . 17 ) lie flat on each other and these surfaces are soldered together, glued or sintered and optionally between the free ends ( 15 ) Separation layers are present to prevent diffusion of the doping elements. Device according to one of claims 1 to 4, characterized in that the p- and n-doped regions are applied by 3D printing and / or screen or offset printing and / or inkjet on a substrate film and are then sintered. Device according to claim 12, characterized in that the thermo legs ( 20 . 22 ) Are formed L-shaped with a long and a short L-leg, wherein the corresponding L-shaped areas ( 20 . 22 ) are arranged alternately such that always one end face ( 23 ) of a long L-leg of an element ( 20 ) on or on a short L-leg ( 24 ) of the respectively adjacent other L-shaped element ( 22 ) is applied, wherein the arrangement of a thermoelectric generator in the cavity, the film or the substrate ( 21 ) and rolled and then or before sintered, the substrate 21 in Hochkanter orientation already has a curvature or a radius or a bend that corresponds to the installation situation. Device according to one of claims 1 to 4, characterized in that the thermal legs with a sputtering method such as a PVD method on a sheet-like substrate ( 30 ) are deposited. Device according to one of claims 1 to 4, characterized in that the thermo legs are produced by laser sintering method thermo legs, wherein on a substrate, a first powder layer is applied, which by means of laser sintering in the corresponding desired shape of the first thermo leg ( 42 ) is sintered according to the desired shape, and then a second powder is applied, which forms the second L-shaped areas, which are also produced by selective laser sintering, at the locations where the L-shaped areas ( 44 ) should be present and then the powder is removed. Device according to one of the preceding claims, characterized in that the thermoelectric material is applied in the form of a cast film or a Foliengießverfahrens and then laser sintered. Device according to one of the preceding claims, characterized in that the thermo legs are produced in a Foliengießverfahren and are accordingly cut out of a film produced by film casting in the desired shape and then adhered to a substrate. Device according to one of the preceding claims, characterized in that the L-shaped elements are formed overlapping to increase the contact surface in adjacent thermo legs and in particular L-shaped thermo legs, wherein the corresponding areas of the L-shaped legs are provided with a step such that the stage of the other L-leg overlaps the former in this area and engages in the step. Device according to one of the preceding claims, characterized in that the thermo legs ( 3 . 4 ) are connected to flexible electrical conductor connections and / or in the areas in which the thermo leg ( 3 . 4 ) are arranged on one another for the production of the electrical line carbon nanotubes or electrically conductive, preferably flexible aerogels are arranged.

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