METHOD FOR PRODUCING A HEAT EXCHANGE AND HEAT EXCHANGER

Abstract

A method for producing a heat exchanger may include: a) applying an adhesive layer to an outer side of heat exchanger tubes by laminating at least one of an adhesive sheet and an adhesive film; b) expanding the tubes on a longitudinal end side in a connecting region via an expanding mandrel; c) arranging the tubes parallel to one another such that the tubes lie flat against one another via the connecting region; and d) heating the adhesive layer at least in the connecting region of the tubes to adhesively bond the tubes to one another via the connecting region.

Claims

1. A method for producing a heat exchanger comprising: a) applying an adhesive layer to an outer side of heat exchanger tubes by laminating at least one of an adhesive sheet and an adhesive film; b) expanding the tubes on a longitudinal end side in a connecting region via an expanding mandrel; c) arranging the tubes parallel to one another such that the tubes lie flat against one another via the connecting regions; and d) heating the adhesive layer at least in the connecting region of the tubes to adhesively bond the tubes to one another via the connecting regions.

2. The method as claimed in claim 1, wherein the adhesive layer is heated in step d) to a temperature of between 80 C. and 400 C.

3. The method as claimed in claim 1, wherein the adhesive layer is heated in step d) for a duration of less than 10 minutes.

4. The method as claimed in claim 1, wherein heating the adhesive layer includes pressing the connecting region of the tubes against one another with a contact pressure of between 0.1 N//mm.sup.2 and 0.7 N/mm.sup.2 to form an adhesively bonded connection.

5. The method as claimed in claim 4, wherein heating the adhesive layer includes heating the expanding mandrel for heating the adhesive layer.

6. The method as claimed in claim 1, wherein the adhesive layer is heated in a furnace.

7. The method as claimed in claim 1, further comprising cooling the adhesive layer after step d).

8. The method as claimed in claim 1, wherein applying the adhesive layer includes forming a layer thickness of between 5 m and 500 m.

9. The method as claimed in claim 1, further comprising inserting a fin structure between two adjacent tubes and adhesively bonding the fin structure to the two adjacent tubes via the adhesive layer.

10. The method as claimed in claim 1, further comprising arranging at least part of a collector in a region of the connecting region of the tubes, the at least part of the collector including the connecting region of the tubes each being arranged on the same side, and adhesively bonding an edge of the at least part of the collector the connecting region of each tube.

11. A heat exchanger comprising: a plurality of tubes having an outwardly expanded longitudinal end structured with a flat connecting region on an outer side thereof; an adhesive layer disposed on the connecting region of the longitudinal end of the plurality of tubes, the adhesive layer including at least one of a laminated adhesive sheet and a laminated adhesive film; and wherein the plurality of tubes are arranged parallel to one another such that the connecting region of each of the plurality of tubes lie flat against one another, and wherein the plurality of tubes are adhesively bonded to one another at the connecting region view the adhesive layer.

12. The heat exchanger as claimed in claim 11, wherein the adhesive layer has a layer thickness of between 5 m and 500 m.

13. The heat exchanger as claimed in claim 11, further comprising a fin structure arranged between two adjacent tubes of the plurality of tubes.

14. The heat exchanger as claimed in claim 13, wherein the fin structure is adhesively bonded to the two adjacent tubes of the plurality of tubes via the adhesive layer.

15. The heat exchanger as claimed in claim 11, further comprising a collector disposed at the longitudinal end of the plurality of tubes, wherein the plurality of tubes open into the collector.

16. The heat exchanger as claimed in claim 15, wherein the collector is a water box.

17. The method as claimed in claim 2, wherein heating the adhesive layer includes pressing the connecting region of the tubes against one another with a predefined contact pressure.

18. The method as claimed in claim 17, wherein the predefined contact pressure ranges from 0.1 N/mm.sup.2 to 0.7 N/mm.sup.2.

19. A method for producing a heat exchanger, comprising: a) applying an adhesive layer to an outer side of heat exchanger tubes by laminating at least one of an adhesive sheet and an adhesive film; b) expanding the tubes on a longitudinal end side in a connecting region via an expanding mandrel; c) arranging the tubes parallel to one another such that the tubes lie flat against one another via the connecting region; and d) adhesively bonding the tubes to one another via the connection region by heating the adhesive layer at least in the connecting region of the tubes to a predefined temperature and pressing the tubes against one another at the connecting region with a predefined contact pressure.

20. The method as claimed in claim 19, wherein at least one of: the predefined temperature is between 80 C. and 400 C.; and the predefined contact pressure is between 0.1 N/mm.sup.2 and 0.7 N/mm.sup.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the drawings, in each case schematically:

[0027] FIG. 1 shows a sectional illustration through a heat exchanger according to the invention with expanding mandrels for expanding longitudinal end-side connecting regions of individual tubes,

[0028] FIG. 2 shows an illustration as in FIG. 1, but without expanding mandrels and with part of a collector.

DETAILED DESCRIPTION

[0029] According to FIG. 1, a heat exchanger 1 according to the invention has tubes 2, the longitudinal end regions 3 of which open according to FIG. 2 into a collector 4, for example a water box, of which only part is illustrated. The tubes 2 are expanded here at the longitudinal end region 3 and are thereby provided with a connecting region 5 via which they lie against one another and thereby form or bound channels 6 which run in the orthogonal direction with respect to the tubes 2, are arranged between the tubes 2 and run perpendicularly to the plane of the image according to FIGS. 1 and 2. According to the invention, the individual tubes 2 are adhesively bonded to one another via their longitudinal-end-side connecting regions 5, and therefore a tube plate which has customarily been provided up to now in this region can be completely omitted, as a result of which not only can the diversity of parts be reduced, but in addition so too can the weight and the production costs of the heat exchanger 1 according to the invention.

[0030] The heat exchanger 1 according to the invention is produced here as follows: first of all, in a method step a), an adhesive layer 7 is applied to an outer side of the individual tubes 2 by lamination of an adhesive sheet 8 or an adhesive film 9. Such a lamination of the adhesive layer 7 can not only take place here economically, but also extremely precisely and with an extremely small layer thickness. Subsequently, the tubes 2 in method step b) are expanded on the longitudinal end sides in their respective connecting region 5 by means of an expanding mandrel 10, specifically in such a manner that the connecting regions 5 of two adjacent tubes 2 lie flat against each other via the adhesive layer 7 arranged in between. The tubes 2 in method step c) are now arranged parallel to one another such that they lie against one another via their respective connecting regions 5. Subsequently, in method step d), the adhesive layer 7 is heated at least in the connecting regions 5 for the adhesive bonding of the tubes 2 and, as a result, the individual tubes 2 are fixed with respect to one another.

[0031] The adhesive layer 7 can be heated here, for example, to a temperature of between 80 C. and 400 C., wherein the warming or heating has to be applied only for a short time, for example less than 10 min, in particular 2 to 3 min. During the adhesive bonding, the connecting regions 5 can be pressed against one another with a contact pressure of between 0.1 N/mm.sup.2 and 0.7 N/mm.sup.2, for example by means of the individual expanding mandrels, as a result of which a more stable adhesive bond can be achieved. Customarily, however, the pressure in terms of the manufacturing is not applied by the expanding mandrels 10, but rather onto the stack from above and then the latter is brought to a temperature (cf. FIG. 2). Furthermore, the expanding mandrels 10 can have a heating device and can be heated as a result, and therefore the expanding mandrels 10, after applying the contact pressure, can also be used at the same time for local heating of the adhesive layer 7. Alternatively, of course, the adhesive layer 7 can also be heated in a furnace. In order to be able to reduce a cycle time for producing the heat exchanger according to the invention, provision can also be made to cool the adhesive layer 7 after the heating, that is to say after method step d).

[0032] The adhesive layer 7 is preferably applied here with a layer thickness of between 5 m and 500 m, that is to say partly with a very small layer thickness which, however, permits electrical insulation and a reliable connection and a certain elasticity between the components adhesively bonded to one another. The electrical insulation is particularly of great advantage here if, for example, tubes 2 and/or other components of different materials, that is to say with different electrical potentials, are intended to be connected to one another.

[0033] For example, a fin structure 11, in particular in the manner of corrugated fins, can be introduced in the channels 6, that is to say between the individual tubes 2, said fin structure likewise being fixed to the opposite outer sides of two adjacent tubes 2 via the adhesive layer 7. The fin structure 11 can be introduced here before the tubes 2 are adhesively bonded to one another or after same.

[0034] Looking once again at FIG. 2, it is possible to see that at least part of the collector 4 is arranged in the region of the connecting regions 5, said part comprising the connecting regions 5 and lying with an edge 12 against the adhesive layer 7 of a connecting region 5 of an outer tube 2 and being adhesively bonded to the latter. The collector 4 is only partially illustrated here according to FIG. 2.

[0035] With the production method according to the invention and the heat exchanger 1 according to the invention, the latter can therefore be produced simply and more cost-effectively, with it being possible at the same time to connect a wide variety of materials having different coefficients of thermal expansion and corrosion potential to one another, with at the same time a minimum use of adhesive. In addition, the lamination of the adhesive layer 7 onto an application of such an adhesive in bead form, which is associated with a significantly increased requirement of material, can be dispensed with. This also simplifies the processing of the adhesive considerably since, for example, no pumps, nozzles or valves which have to be cleaned in a complicated manner retrospectively are required. By means of the comparatively rapid curing time of the adhesive layer 7 according to the invention, the cycle time for the production of the heat exchanger 1 according to the invention can also be reduced, which likewise has an advantageous effect on the production costs. In comparison to brazing connections which have been used up to now in this region, the adhesive layer 7 which is used is also significantly more cost-effective than, for example, expensive brazing metal and, in addition, a complicated removal of fluxing agent residues is omitted. The significantly reduced amount of energy which is required can also be considered to be a further advantage of the adhesive connections. It is above all also possible to use materials which cannot be brazed but which can be tightly connected to one another by means of the adhesive connection according to the invention.