US20200333052A1

US20200333052A1 - Thermoelectric flexible mat

Info

Publication number: US20200333052A1
Application number: US16/852,375
Authority: US
Inventors: Juergen GRUENWALD; Stefan Hoppe; Thomas Pfadler; Gerhard Span; Arno Wehner
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2019-04-18
Filing date: 2020-04-17
Publication date: 2020-10-22
Also published as: CN111823974A; DE102019205714A1

Abstract

A thermoelectric flexible mat may include a first large surface and a second large surface. The mat may also include a plurality of p-doped elements and a plurality of n-doped elements disposed in an alternating manner with one another and electrically interconnected to a series circuit via a plurality of electrically conductive conductor bridges. The plurality of conductor bridges of the series circuit may be assigned, at least in regions, to the first large surface and the second large surface such that the first large surface defines a hot side and the second large surface defines a cold side. An absorptive absorption structure may connect the hot side and the cold side. The absorption structure may be structured and arranged such that any liquid present on the cold side is absorbable into the absorption structure and transportable to the hot side via the absorption structure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. DE 10 2019 205 714.4, filed on Apr. 18, 2019, the contents of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to a thermoelectric flexible mat, which is provided in particular for temperature-controlling a vehicle seat of a motor vehicle.

BACKGROUND

To increase the comfort of the passengers in a motor vehicle, work is currently undertaken regarding temperature-controlling the interior surfaces and in particular the vehicle seats. In particular, a thermoelectric mat can be employed for this purpose. When cooling the interior surfaces, the dew point of the ambient air is lowered as a result of which the water contained in the ambient air can condense. If the condensate is not discharged from the thermoelectric mat, the same can be wet through. There are currently no solutions for discharging the condensate known from the prior art.

SUMMARY

The object of the invention therefore is to state an improved or at least alternative embodiment for a thermoelectric flexible mat of the generic type, in which the described disadvantages are overcome.
According to the invention, this object is solved through the subject matter of the independent claim(s). Advantageous embodiments are subject of the dependent claim(s).
A thermoelectric flexible mat is provided in particular for temperature-controlling a vehicle seat of a motor vehicle and has a first large surface and a second large surface located opposite the first large surface. In addition, the mat comprises p-doped and n-doped elements, which, alternating with one another, are electrically interconnected via electrically conductive conductor bridges to form a series circuit. The elements can consist for example of a semiconductor material. The respective conductor bridges of the series circuit are assigned at least in regions to the first large surface of the mat and the second large surface of the mat, so that the first large surface of the mat represents a hot side and the second large surface a cold side or vice versa. According to the invention, the mat has an absorptive absorption structure, which connects the hot side and the cold side of the mat. A liquid condensed or present on the cold side can then be absorbed into the absorption structure and, via the absorption structure, transported to the hot side. On the cold side, the heat is absorbed and on the hot side the absorbed heat, plus the consumed electric power, dissipated. The absorptive absorption structure connects the cold side and the hot side and can transport the liquid, through the capillary effect or through the Marangoni effect or through the suction effect on the cold side and transport the same through the capillary force to the hot side. When the liquid—for example condensate or perspiration—is present on the cold side of the mat, the same is absorbed by the absorption structure and transported to the hot side of the mat. On the hot side, the liquid from the absorption structure can evaporate and the evaporated liquid passed on into the surroundings. On the hot side, the local transport away of the evaporated liquid can be convectively supported—for example by means of a fan or however by means of any device for the convective heat dissipation. In an ideal case, the absorption structure is not saturated with the liquid so that the liquid can be continuously transported from the cold side to the hot side and dissipated into the surroundings.
When the liquid is condensed on the cold side, condensation heat is incurred. Accordingly, additional electric power is incurred, which, dependent on the comfort sensation of the passengers, can be determined and suitably readjusted. By transporting the liquid away to the hot side and the subsequent evaporation of the same on the hot side, an additional cooling effect can be additionally generated which favours the heat dissipation. Since the heat dissipation is always one of the substantial challenges, the efficiency of the thermoelectric mat can thereby be increased. The condensation and evaporation enthalpy of the liquid largely correspond to one another. By contrast, the heating output in the real operating case is always substantially greater than the cooling output because of the consumed electric power, so that the heat incurred on the hot side is always sufficient for evaporating the liquid condensed on the cool side.
In the mat according to the invention, the liquid present or condensed on the cold side can be transported to the hot side and passed on into the surrounding air. In particular, a wetting-through of the mat that can occur in an extreme case can thereby be prevented and the comfort of the passengers significantly increased. No further moving parts are present and necessary in the mat so that the mat remains maintenance-free. The absorptive absorption structure is comparatively cost-effective, so that the costs of the mat are not increased or only insignificantly so. Furthermore, the installation space required by the mat is not increased or only insignificantly so. In addition, the efficiency of the mat can be increased through the evaporating of the liquid on the hot side.
In an advantageous embodiment of the thermoelectric mat it is provided that the mat is a fabric. The fabric comprises a plurality of first threads and a plurality of second threads. The second threads are preferentially electrically insulating. The first threads then form the weft threads and the second threads form the warp threads of the fabric, or vice versa. Furthermore, the first threads are alternately formed by p-doped and n-doped thread portions and electrically conductive first and second thread portions arranged in between. The p-doped first thread portions form the respective p-doped P-elements of the mat and the n-doped first thread portions form the respective n-doped N-elements of the mat. The second thread portions arranged in between then form the respective conductor bridges of the mat. In the present context, the term “thread” is chosen merely to better understand the structure of the fabric. Thus, the second threads can be formed by foam material blocks of an electrically insulating foam material. The first threads can be formed by wide flexible webs, which comprise p-doped, n-doped and electrically conductive web portions. The fabric can then be formed in that the flexible webs are guided about the non-deformed or only slightly deformed foam material blocks or intertwined with these. The respective web portions are arranged corresponding to the cold side or the hot side on the foam material blocks and between the adjacent foam material blocks.
Advantageously, the absorptive absorption structure can be formed independently of the embodiment by a plurality of absorption threads. Here, at least some of the absorption threads can extend between the cold side and the hot side perpendicularly to these. Advantageously, the cross section of at least some of the absorption threads can be round or oval or quadrangular. However, differently shaped cross sections of the absorption threads are also conceivable. The diameter of at least some of the absorption threads can be between 0.5 mm and 1.5 mm. At least some of the absorption threads can be braided of multiple individual threads. In the thermoelectric fabric, at least some of the absorption threads can follow adjacent to the first threads of the fabric. It is also conceivable that at least some of the absorption threads are embedded into the second threads at least in regions. It is conceivable, furthermore, that at least some of the absorption threads are arranged between the adjacent second threads.
In an advantageous embodiment of the absorptive absorption structure it can be provided that the same consists of hydrophilic fibres or of hydrophilic particles or of hydrophilic moulding compounds. The absorptive absorption structure can be formed of conjugate fibres or of mixed spinning fibres or of staple fibres. It is conceivable that the absorptive absorption structure is formed of a non-woven fabric or of a fabric or of a knitted fabric or of a twisted cloth. The absorptive absorption structure can be formed of hollow fibres or of solid fibres.
The absorptive absorption structure can consist of synthetic or natural organic materials or of inorganic materials or of a combination of these materials. Possible synthetic organic materials are for example a viscose base, a cellulose base, polyolefin and a polyolefin base—in particular polyethylene, polypropylene, polybutene-1, polypentene-1 as well as statistical copolymers or block copolymers thereof, —polyester and a polyester base. In the case of the natural organic materials, cotton or hemp are conceivable for example. Regarding the inorganic materials, ceramic can be employed for example.
Advantageously, the absorptive absorption structure can consist of two-part fibres having a core and a sheathing. Here, the core and/or the sheathing can consist of polyethylene or of polypropylene or of polyethylene-vinyl-acetate copolymerisate or of polyester in particular polyethylene terephthalate, polybutene terephthalate or polyethylene terephthalate isophthalate-copolymerisate or of polyamide, in particular of polyhexamethylene adipic acid amine. Polyhexamethylene adipic acid amine is also known under the trademark nylon®. The hydrophilic nature depends on the mixing ratio between for example polyethylene and the phthalates and can thus be adjusted.
The absorptive absorption structure can consist of coated fibres. At least some components of the thermoelectric mat can be formed of a metal foam.
Further important features and advantages of the invention are obtained from the sub claims, from the drawings and from the associated figure description by way of the drawings.
It is to be understood that the features mentioned above and still to be explained in the following cannot only be used in the respective combinations stated but also in other combinations or by themselves without leaving the scope of the present invention.
Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein same reference numbers relate to same or similar or functionally same components.

BRIEF DESCRIPTION OF THE DRAWINGS

It shows, in each case schematically

FIGS. 1 and 2 show sectional views of a thermoelectric material according to the invention with in each case a differently configured absorptive absorption structure.

DETAILED DESCRIPTION

FIGS. 1 and 2 show sectional views of a thermoelectric mat 12 according to the invention, in particular for temperature-controlling a vehicle seat of a motor vehicle. In this exemplary embodiment, the mat 12 is a thermoelectric fabric 1. Basically, however, other embodiments of the mat 12 are also conceivable. The fabric 1 has a first large surface 13 a and a second large surface 13 b, which are arranged opposite one another. The fabric 1, furthermore, comprises a plurality of first threads 2—only one visible here—and a plurality of second threads 3. Here, the first threads 2 form the warp threads 2 a and the second threads 3 the weft threads 3 a of the fabric 1. The first threads 2 are alternately formed by p-doped thread portions 4 and n-doped thread portions 5 as well as electrically conductive first thread portions 6 and electrically conductive second thread portions 7 arranged in between. The first threads 2 of the fabric 1 thus constitute a series circuit. The individual threads 2—only one shown here however—can be electrically interconnected. The first thread portions 6 are assigned to the first large surface 13 a and then form a hot side 8 of the fabric 1 and the second thread portions 7 are assigned to the second large surface 13 b of the fabric 1 and then form a cold side 9 of the fabric 1. The second threads 3 are preferentially electrically insulating.
Furthermore, the fabric 1 comprises an absorptive absorption structure 10, which connects the hot side 8 and the cold side 9. The absorption structure 10 is formed of multiple absorption threads 11. In FIG. 1, the absorption threads 11—only one visible here—adjacently follow the first threads 2 of the fabric 1. In FIG. 2, the multiple absorption threads 11 are orientated perpendicularly to the cold side 9 and to the hot side 8 and lie between the adjacent second threads 3. In the fabric 1, the heat is absorbed on the cold side 9 and on the hot side 8, the absorbed heat plus the consumed electric power is then dissipated. Regardless of its configuration, the absorptive absorption structure 10 connects the hot side 8 and the cold side 9 and can absorb the liquid—for example condensate or perspiration—present on the cold side 9 by way of the capillary effect or by way of the Marangoni effect or by way of the suction effect. By way of the capillary force, the absorbed liquid can be transported via the absorption threads 11 to the hot side 8 and evaporate there. Because of this, any wetting-through of the fabric 1 that can occur in an extreme case can be prevented.

Claims

1. A thermoelectric flexible mat comprising:

a first large surface and a second large surface disposed opposite the first large surface;

a plurality of p-doped elements and a plurality of n-doped elements disposed in an alternating manner with one another and electrically interconnected to a series circuit via a plurality of electrically conductive conductor bridges;

wherein the plurality of conductor bridges of the series circuit are assigned, at least in regions, to the first large surface and the second large surface such that the first large surface defines a hot side and the second large surface defines a cold side; and

wherein an absorptive absorption structure connects the hot side and the cold side the absorption structure structured and arranged such that any liquid present on the cold side is absorbable into the absorption structure and transportable to the hot side via the absorption structure.

2. The mat according to claim 1, wherein:

the mat is structured as a fabric and includes a plurality of first threads and a plurality of second threads;

the plurality of first threads define a plurality of warp threads of the fabric and the plurality of second threads define weft threads of the fabric;

the plurality of first threads are defined by a plurality of p-doped first thread portions and a plurality of n-doped first thread portions disposed in an alternating manner, and a plurality of electrically conductive first thread portions and a plurality of electrically conductive second thread portions arranged in between;

the plurality of p-doped first thread portions define the plurality of p-doped elements and the plurality of n-doped first thread portions define the plurality of n-doped elements; and

the plurality of first thread portions and the plurality of second thread portions define the plurality of conductor bridges.

3. The mat according to claim 1, wherein the absorption structure is defined by a plurality of absorption threads.

4. The mat according to claims 2, wherein the absorption structure is defined by a plurality of absorption threads, and wherein at least one of:

at least some of the plurality of absorption threads adjacently follow the plurality of first threads;

at least some of the plurality of absorption threads are embedded, at least in regions, in the plurality of second threads; and

at least some of the plurality of absorption threads are arranged between adjacent second threads of the plurality of second threads.

5. The mat according to claim 3, wherein at least some of the plurality of absorption threads extend between the cold side and the hot side perpendicularly thereto.

6. The mat according to claim 3, wherein at least one of:

a cross section of at least some of the plurality of absorption threads is one of round oval, and quadrangular;

a diameter of at least some of the plurality of absorption threads is 0.5 mm to 1.5 mm; and

at least some of the plurality of absorption threads are braided threads defined by a plurality of individual threads.

7. The mat according to claim 1, wherein the absorption structure includes at least one of hydrophilic fibres, hydrophilic particles, and hydrophilic moulding compounds.

8. The mat according to claim 1, wherein the absorption structure includes at least one of synthetic organic materials, natural organic materials and inorganic materials.

9. The mat according to claim 1, wherein at least one of:

the absorption structure is defined by at least one of conjugate fibres mixed spinning fibres and staple fibres;

the absorption structure is defined by at least one of a non-woven fabric, a fabric, a knitted fabric, and a twisted cloth;

the absorption structure is defined by at least one of hollow fibres and solid fibres.

10. The mat according to claim 1, wherein the absorption structure includes a plurality of two-part fibres each having a core and a sheathing.

11. The mat according to claim 10, wherein at least one of the core and the sheathing include at least one of polyethylene, polypropylene, polyethylene-vinyl-acetate copolymerisate, polyester, polyethylene terephthalate, polybutene terephthalate, polyethylene terephthalate isophthalate-copolymerisate, polyamide, and polyhexamethylene adipic acid amide.

12. The mat according to claim 2, wherein at least one of:

the absorption structure includes a plurality of coated fibres; and

at least some components of the fabric are formed of a metal foam.

13. A thermoelectric flexible mat, comprising:

a plurality of first threads and a plurality of electrically insulating second threads structured and arranged to define a fabric having a first large surface and a second large surface disposed opposite one another;

each of the plurality of first threads defined by a plurality of p-doped thread portions, a plurality of n-doped thread portions, and a plurality of electrically conductive thread portions, the plurality of p-doped thread portions and the plurality of n-doped thread portions disposed in an alternating manner and electrically interconnected to one another via the plurality of electrically conductive thread portions to define a series circuit;

wherein the plurality of electrically conductive thread portions includes a first subset of tread portions assigned to the first large surface and a second subset of thread portions assigned to the second large surface, the first subset of thread portions and the second subset of thread portions disposed in an alternating manner such that the first large surface defines a hot side of the fabric and the second large surface defines a cold side of the fabric; and

wherein an absorptive absorption structure connects the hot side and the cold side, the absorption structure structured and arranged such that liquid present on the cold side is absorbable into the absorption structure and transportable to the hot side via the absorption structure.

14. The mat according to claim 13, wherein the absorption structure is defined by a plurality of absorption threads that extend along and adjacent to the plurality of first threads.

15. The mat according to claim 13, wherein the absorption structure is defined by a plurality of absorption threads that extend from the cold side to the hot side and that are arranged between adjacent second threads of the plurality of second threads.

16. The mat according to claim 13, wherein the plurality of second threads are at least partially composed of a foam material.

17. The mat according to claim 13, wherein one of:

the plurality of first threads and the plurality of second threads are woven together such that the plurality of first threads define warp threads of the fabric and the plurality of second threads define weft threads of the fabric; and

the plurality of first threads and the plurality of second threads are woven together such that the plurality of first threads define weft threads of the fabric and the plurality of second threads define warp threads of the fabric.

18. The mat according to claim 13, wherein the absorption structure is defined by a plurality of braided absorption threads.

19. The mat according to claim 13, wherein the absorption structure is defined by a plurality of absorption threads having a diameter of 0.5 mm to 1.5 mm.

20. The mat according to claim 13, wherein the absorption structure is defined by a plurality of coated fibres.