HEAT EXCHANGER

Abstract

The invention relates to a heat exchanger (1) having a main part (2), which is thermally coupled to carbon nanostructure-based fibers (CNB), in particular carbon nanotubes (CNT). At least one gas channel (3) is provided and is formed by the main part (2) to at least some, the carbon nanostructure-based fibers (CNB) at least partially extending through the gas channel (3).

Claims

1. A heat exchanger (1) having a main body (2) which is in thermal communication with carbon nanostructure-based fibers (CNB), characterized by at least one gas channel (3) which is at least partially formed by the main body (2), wherein the carbon nanostructure-based fibers at least in regions extend in the gas channel (3).

2. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) extend along the cross section (9) of the gas channel (3), wherein the cross section (9) extends transversely to the longitudinal extent of the gas channel (3).

3. The heat exchanger as claimed in claim 1, characterized in that the heat exchanger (1) is directly connected or connectable to a heat source.

4. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) at least in regions extend substantially parallel to one another.

5. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) form a net (14).

6. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) form a braid.

7. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) form a weave (15).

8. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) form a knit.

9. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) are directly connected to the main body (2).

10. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) are held by a thermally conductive holder body (12) which is arranged in the main body (2) and is in thermal communication therewith.

11. The heat exchanger as claimed in claim 10, characterized in that the holder body (12) is a holder frame (13).

12. The heat exchanger as claimed in claim 1, characterized in that a plurality of holder bodies (12) and/or cross sections (9) formed by carbon nanostructure-based fibers (CNB) are serially arranged in the main body (2) along the longitudinal extent thereof.

13. The heat exchanger as claimed in claim 1, wherein the carbon nanostructure-based fibers (CNB) are carbon nanotubes (CNT).

14. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) extend along a cross-sectional area of the gas channel (3), wherein the cross-sectional area extends transversely to the longitudinal extent of the gas channel (3).

15. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) extend along a cross-sectional plane (10) of the gas channel (3), wherein the a cross-sectional plane (10) extends transversely to the longitudinal extent of the gas channel (3).

16. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) extend along a cross-section of the gas channel (3), wherein the cross section (9) extends perpendicularly to the longitudinal extent of the gas channel (3).

17. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) extend along a cross-sectional plane (10) of the gas channel (3), wherein the a cross-sectional plane (10) extends perpendicularly to the longitudinal extent of the gas channel (3).

18. The heat exchanger as claimed in claim 1, characterized in that the heat exchanger (1) comprises a medium channel (8) which is traversable or traversed by a cooling liquid for indirect connection to the heat source.

19. The heat exchanger as claimed in claim 1, characterized in that the carbon nanostructure-based fibers (CNB) form a wire mesh.

20. The heat exchanger as claimed in claim 1, characterized in that a plurality of holder bodies (12) and/or cross cross-sectional areas, formed by carbon nanostructure-based fibers (CNB) are serially arranged in the main body (2) along the longitudinal extent thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention is elucidated with reference to exemplary embodiments in the figures, in which:

[0018] FIG. 1 shows a cross section through a heat exchanger comprising carbon nanostructure-based fibers,

[0019] FIG. 2 shows the heat exchanger of FIG. 1 in cross section, but with a holder body for the carbon nanostructure-based fibers,

[0020] FIG. 3 shows another exemplary embodiment of a heat exchanger in cross section with fibers structured in a net-like fashion in the manner of a wire mesh, and

[0021] FIG. 4 shows a heat exchanger in cross section according to a further exemplary embodiment with carbon nanostructure-based fibers forming a weave.

DETAILED DESCRIPTION

[0022] FIG. 1 is a schematic view of a heat exchanger 1 comprising a main body 2. The main body 2 is configured as a gas channel 3. The gas channel 3 has a rectangular, preferably square, cross section and thus two base walls 4 and 5 and two side walls 6 and 7. The base walls 4 and 5 are opposite one another in parallel and the side walls 6 and 7 are likewise opposite one another in parallel. The gas channel 3 is an air channel. This means that a cooling gas, preferably air, flows through it. The flow may be effected by natural convection or by forced convection, for example by means of a blower (not shown).

[0023] The gas channel 3 has a cross section 9. Located in a cross-sectional plane 10 which extends perpendicularly to the longitudinal extent of the gas channel 3 are a multiplicity of carbon nano-based fibers (CNB) which are in the form of carbon nanotubes (CNT). In the exemplary embodiment of FIG. 1, the carbon nanostructure-based fibers (CNB) extend substantially parallel to one another. Said fibers extend between the two base walls 4 and 5, preferably over the entire cross-sectional plane 10, i.e. a multiplicity of carbon nanostructure-based fibers (CNB) extend parallel to one another over the entire width of the gas channel 3. The carbon nanostructure-based fibers (CNB) are in thermal communication with the gas channel 3.

[0024] Arranged on the outside of the gas channel 3, in the exemplary embodiment of FIG. 1 on the base wall 4, is an article 11 which becomes hot in operation and may be in the form of a high performance electronic component, for example. When this article 11 becomes hot in operation, it emits its heat to the medium channel 3. From the medium channel 3, the heat then passes to the thermally very conductive carbon nanostructure-based fibers (CNB), in particular carbon nanotubes (CNT). A gas stream (not shown) flowing through the medium channel 3 dissipates the heat from the carbon nanostructure-based fibers (CNB).

[0025] The exemplary embodiment of FIG. 2 corresponds substantially to the exemplary embodiment of FIG. 1. In FIGS. 2 to 4, the article 11 is not shown for the sake of simplicity. The carbon nanostructure-based fibers (CNB) are in thermal communication with a thermally conductive holder body 12 which is in the form of a holder frame 13. In the exemplary embodiment of FIG. 2, carbon nanostructure-based fibers (CNB) are arranged extending parallel to one another on the holder frame 13. The holder frame 13 is arranged on the main body 2, preferably such that the frame cross-sectional area is perpendicular to the longitudinal extent of the main body 2. The exemplary embodiment of FIG. 2 has the advantage that the stringing of the holder frame 13 with the carbon nanostructure-based fibers (CNB) may be carried out outside the main body 2. Once this has been done, the strung holder frame 13 is inserted in the main body 2. The inserting is carried out such that there is thermal communication between the holder frame 13 and the main body 2. Press-fitting of the holder frame 13 in the main body 2 is conceivable. In the present exemplary embodiment, the heat exchanger 1 further comprises a medium channel 8 which especially passes cooling medium liquid from a heat source to the heat exchanger 1.

[0026] Not shown is an exemplary embodiment which corresponds to FIG. 1 or 2 and differs therefrom in that a plurality of fiber cross sections or holder frames 13 are serially arranged in the main body 2 along the longitudinal extent thereof. This brings about a corresponding enlargement of the surface area of the carbon nanostructure-based fibers (CNB).

[0027] The exemplary embodiment of FIG. 3 corresponds to the exemplary embodiment of FIG. 2, but differs therefrom merely in that the carbon nanostructure-based fibers (CNB) do not extend parallel to one another, but instead form a net 14, preferably in the manner of a wire mesh.

[0028] The exemplary embodiment of FIG. 4 comprises a heat exchanger 1 corresponding to FIG. 1, but likewise does not employ carbon nanostructure-based fibers (CNB) extending parallel to one another, instead rather a weave 15 consisting of carbon nanostructure-based fibers (CNB).

[0029] The invention is especially employable in the field of electric vehicles, namely for cooling output peaks of high performance electronic components. It is preferable when forced convection of air is generated in the medium channel 3 using a blower. The large heat exchanger surface area generated by the carbon nanostructure-based fibers (CNB) is advantageous, this ensuring very good heat transfer from the solid to the flowing gas, especially to the flowing air. It is preferable to employ carbon nanostructure-based fibers (CNB), in particular fibers composed of CNT or graphene platelets, having a diameter of 5 μm and especially having a thermal conductivity >800 W/mK. In addition, such a material has a very high tensile strength >1 GPa, thus making it possible to realize very delicate structures having sufficient resilience. It is further advantageous that textile methods, such as knitting, braiding or weaving, may be employed to achieve structures with the carbon nanostructure-based fibers (CNB) through which the cooling medium, namely the cooling gas, in particular the air, may flow. Such textile elements are also particularly amenable to prefabrication.

[0030] Employed for example is a heat exchanger 1 provided with a holder frame 13, wherein the holder frame 13 has a width of 10 cm and a height of 3 cm. Said frame can accommodate preferably 2000 windings of the carbon nanostructure-based fibers (CNB). These carbon nanostructure-based fibers (CNB) especially have a diameter of 10 μm. Such a holder frame 13 results in a heat exchanger surface area of 0.0037 m.sup.2. When about 30, preferably 33, such holder frames 13 are serially arranged in a medium channel 3 of a heat exchanger 1, this results in a heat exchanger surface area of 0.124 m.sup.2. This makes it possible to realize an effective heat exchanger 1 even in a small space and by the simplest means of production.

[0031] The same applies to heat exchangers 1 which comprise carbon nanostructure-based fibers (CNB) in the form of a braid of a net cloth (in particular wire mesh) or which comprise a knit or weave. A knit or weave preferably comprises numerous weft threads, since these form a direct connection with the medium channel 3.

[0032] The highly efficient heat exchangers 1 according to the invention are—as mentioned—employable especially in high performance electronics. However, further applications include air-conditioning systems, household appliances and the like. As mentioned hereinabove, such heat exchangers 1 are suitable not only for cooling, but also for heating.