DE102016111201B4 - Process for manufacturing a heat exchanger - Google Patents

Abstract

Method for producing a heat exchanger, which has a heat exchanger box (14) forming an inlet (22) and/or an outlet as well as a tube plate (10) and a plurality of heat exchanger tubes (12), the ends of which are each inserted into a receiving opening of the tube plate (10). and fixed therein in a sealed manner, wherein the heat exchanger tubes (12) are pushed into the receiving openings to such an extent that their ends form a protrusion from the tube sheet (10), and then the tube sheet (10) rests on the protruding ends of the heat exchanger tubes ( 12) the side facing is coated with a casting material (16), characterized in that the free surface formed by the casting material (16) and/or the ends of the heat exchanger tubes (12) is/are post-processed in order to prevent the heat exchanger tubes (12) from protruding to reduce or remove the casting material (16) and/or to pipe openings (18) previously covered by the casting material (16) to expose the heat exchanger tubes (12).

Description

The invention relates to a method for producing a heat exchanger which comprises a heat exchanger box forming an inlet and/or an outlet as well as a tube plate and a plurality of heat exchanger tubes, the ends of which are each inserted into a receiving opening of the tube plate and fixed therein in a sealed manner. The heat exchanger is intended in particular for use in a motor vehicle, for example as a so-called main cooler, although all other gas-liquid or gas-gas coolers can also be designed accordingly.

In a main radiator of a motor vehicle, waste heat generated by a drive system of the motor vehicle is transferred to ambient air flowing through and around it.

Heat exchangers, which are provided as the main cooler of a motor vehicle, are generally designed as tube coolers and in particular as flat tube coolers. In such a (flat) tube cooler, two elongated heat exchanger boxes are usually provided, which are aligned parallel to one another in the direction of their longitudinal extensions, with a plurality of heat exchanger tubes (possibly designed as flat tubes) extending between the heat exchanger boxes and with their open ends in the heat exchanger boxes open out, whereby a cooling liquid, which was fed to the heat exchanger via an inlet integrated into one of the heat exchanger boxes and which is to be discharged again via an outlet integrated into one of the heat exchanger boxes, can flow through the heat exchanger tubes in order to cool the ambient air flowing around the heat exchanger tubes by heat transfer will. In order to improve this heat transfer from the cooling liquid to the cooling air, it is generally also provided to provide the heat exchanger tubes with so-called fins, which are flat elements made of a material that conducts heat well, in particular aluminum, whose function is to dissipate Heat energy from the heat exchanger tubes and an improved transfer of the heat energy to the ambient air as a result of an increase in the heat transfer area of the heat exchanger. The fins can be designed, for example, in the form of corrugated metal sheets, which are each arranged between two adjacent heat exchanger tubes and connect them to one another, as a result of which the structural stability of the heat exchanger is additionally increased.

Such heat exchangers are also relatively easy to manufacture due to the relatively small number (less than twenty, for example) of heat exchanger tubes and are correspondingly inexpensive. In particular, for the production of such a heat exchanger it can be provided that all components are positioned relative to one another by means of a frame in the intended end position, with solder already being present in the intended connection points between the components, and the components positioned relative to one another are transferred to a soldering furnace in order to temporarily reflow the solder, thereby forming solder joints. A problem with a heat exchanger produced in this way, however, can be the attainment of sufficient durability of the partially also sealing soldered connections with regard to alternating thermal stress to which such a heat exchanger is exposed during operation.

From the EP 1 061 322 A2 a heat exchanger used as a charge air cooler for an internal combustion engine is known, which is designed in a flat-tube design. In this case, the ends of the heat exchanger tubes are inserted into corresponding receiving openings in the tube sheets of the heat exchanger boxes and fixed therein in a sealingly materially bonded manner. In addition, it is provided to apply a layer of an elastomer to the side of the tube bases that represents an inner side of the respective heat exchanger box, as a result of which the tube bases are intended to be thermally insulated from the hot charge air flowing through the heat exchanger boxes. This is intended to enable the components of the heat exchanger to be heated as uniformly as possible, which in turn is intended to improve the resistance to thermal cycling of the material-locking connections.

the U.S. 2002/0162648 A1 also discloses a flat tube heat exchanger. In this case, the heat exchanger tubes inserted into corresponding receiving openings in the tube sheets of the heat exchanger boxes are sealed by means of an elastic material, in particular silicone, which is arranged at least in those gaps that are formed between the surfaces of the tube sheets delimiting the receiving openings and the adjacent sections of the outsides of the heat exchanger tubes are. The elastic material can be designed in the form of a preformed sealing element made of material that has already hardened. There is also the possibility of applying this in non-cured form to the outside or inside of the tube sheets and allowing it to cure. The elastic material is intended to achieve relative mobility of the heat exchanger tubes with respect to the tube sheets, as a result of which different thermally induced elongations can be compensated for without this leading to leaks.

Heat exchangers in the described (flat) tubular design are comparative can be produced easily and inexpensively, but have a relatively poor specific cooling capacity with regard to the required structural size and/or with regard to the flow resistance for, in particular, the ambient air flowing through them. On the other hand, so-called micro-channel heat exchangers have a better specific cooling capacity in this respect, in which the heat exchanger tubes have comparatively small cross-sectional dimensions of, for example, less than two millimeters in outside diameter and are provided in a large number of, for example, more than 10,000 (when used as the main cooler of a motor vehicle). It is obvious that the production of such a microchannel heat exchanger is complex and consequently expensive due to the large number of heat exchanger tubes. The sealing of the individual heat exchanger tubes in the receiving openings formed by the tube sheets of the heat exchanger boxes is often particularly problematic.

A microchannel heat exchanger is, for example, from U.S. 2012/0211158 A1 famous. In this case, the tube bases of the cooler boxes have a sandwich structure consisting of at least two layers, with the layers forming at least one intermediate space into which a flowable connecting agent, for example solder or a curable adhesive, is introduced. The connecting agent is distributed both within the intermediate space and in the gaps between the heat exchanger tubes and the surfaces that delimit the receiving openings of the tube sheets provided for receiving the heat exchanger tubes, as a result of which these gaps are sealed and the heat exchanger tubes are connected to the tube sheets. In one embodiment, it can also be provided that an additional layer of a hardenable adhesive is applied both to the upper width and to the underside of the tube sheets.

In the micro-channel heat exchanger according to U.S. 2012/0211158 A1 it is provided that the ends of the heat exchanger tubes have a projection with respect to the tube sheets of the heat exchanger boxes and consequently protrude into the interior spaces of the heat exchanger boxes that are filled with the heat exchange fluid. This leads to an unfavorable deflection of the flows of the heat exchange fluid when flowing between the heat exchanger boxes and the heat exchanger tubes, which is accompanied by a relatively large flow resistance that is not wanted at this point.

the U.S. 5,865,244A discloses a heat exchanger and an associated manufacturing method, wherein the heat exchanger tubes are attached to a heat exchanger box by plastic injection molding, flush or with an overhang.

the DE 102 54 797 B4 discloses a heat exchanger having a heat exchanger box with flush embedded heat exchanger tubes.

the DE 600 17 830 T2 discloses a charge air cooler having a header with flush or overhanging heat exchange tubes embedded by means of an elastomeric material.

the DE 10 2009 052 121 A1 discloses a heat exchanger with a retaining plate in which the heat exchanger tubes are partially flush, partially protrude or end in the retaining plate, the heat exchanger tubes being overmolded with the plastic material of the retaining plate by means of injection molding.

the DE 10 2014 218 677 A1 discloses a heat exchanger and an associated manufacturing method, in the context of which a tube plate of a collecting box is molded directly onto a heat transfer block by means of a plastic injection molding process. The tubes protruding through the tube sheet are connected in a material-to-material and/or form-fitting manner.

Finally is out of the WO 2015/063169 A1 a method for producing a heat exchanger is known, in which the individual heat exchanger tubes are provided at the end with a peripheral contour formed by injection molding, which can in particular be cuboid, with these peripheral contours making it possible to combine a large number of heat exchanger tubes in a flexible manner by stacking them on top of one another to form a heat exchanger , The peripheral contours then connected to one another forming tube sheets for heat exchanger boxes.

The invention was based on the object of specifying a possibility for the cost-effective production of a heat exchanger designed in particular as a microchannel heat exchanger, the heat exchanger also being characterized by a relatively low flow resistance for an overflow of a heat exchange fluid between the heat exchanger box or boxes and the heat exchanger tubes.

This object is achieved by means of a method according to patent claim 1. Advantageous embodiments of the method according to the invention are the subject matter of the further patent claims and result from the following description of the invention.

A generic method for producing a heat exchanger, which has at least one heat exchanger box (preferably two heat exchanger boxes) having an inlet and/or an outlet and a tube sheet a plurality of heat exchanger tubes, the ends of which are each inserted into a receiving opening in the tube sheet of the heat exchanger box or boxes and fixed therein in a sealed manner, provides that the heat exchanger tubes are inserted into the receiving openings to such an extent that their ends protrude from the (respective) Train tube sheet, and then the tube sheet is coated on the protruding ends of the heat exchanger tubes facing side with a potting material. In a subsequent method step, the potting material can be cured in order to form a sealed connection between the tube sheet and the heat exchanger tubes. According to the invention, such a generic method is characterized in that the free surface formed by the casting material (or the surface facing away from the coated side of the tube sheet) and/or the ends of the heat exchanger tubes is/are reworked in order to reduce or reduce the overhang of the heat exchanger tubes with respect to the casting material to remove and / or to expose covered by the potting pipe openings of the heat exchanger tubes.

A method according to the invention can be used to produce a heat exchanger in which the heat exchanger tubes are advantageously connected to the tube sheet of the or each heat exchanger box in a sealing manner by means of a casting compound, which can be carried out quickly and easily. This procedure is further simplified by the fact that the casting material is applied to that side of the tube sheet which delimits the interior space of the corresponding heat exchanger box in the finally manufactured heat exchanger. This side of the tube sheet can be easily accessible, which also simplifies the application of the potting material, for example. Post-processing of the surface formed by the casting material and/or the ends of the heat exchanger tubes means that the ends of the heat exchanger tubes do not protrude from the casting material, or at least it is reduced, resulting in a relatively low flow resistance for a heat exchange fluid, in particular a heat exchange liquid, to flow over between the ( respective) heat exchanger box and the heat exchanger tubes.

A particularly advantageous overflow between the heat exchanger box or boxes and the heat exchanger tubes can be achieved if the end faces (of the corresponding ends) of the heat exchanger tubes are flush with the surface of the casting material, so that in a preferred embodiment of the method according to the invention a corresponding post-processing is provided.

According to the invention, “potting material” is a material that can be used to produce a gapless layer in which the end sections of the heat exchanger tubes, which represent the overhang relative to the tube sheet, can be embedded without gaps. Such a casting material can in particular be liquid or pasty in at least one processing state during the implementation of the method according to the invention in order to, through a corresponding flow behavior, preferably exclusively due to the force of gravity, but possibly also under the exertion of pressure on the casting material and/or through the generation of vibrations, to achieve the desired gaplessness (i.e. not forming gaps causing leakage) of the layer formed from the potting material. It is not necessary for the potting material to be in a liquid or pasty state when it is applied to the tube sheet. Rather, provision can also be made, for example, for the casting material to be applied in the form of solid particles and for example to be temporarily converted into the liquid or pasty state by influencing the temperature.

As part of the method according to the invention, it can be provided that the casting material is applied to the corresponding side of the tube sheet of the heat exchanger box or boxes in a layer thickness that is less than the overhang of at least some, possibly all of the heat exchanger tubes with respect to the tube sheet, so that the post-processing can primarily be used to reduce or remove a projection of these heat exchanger tubes with respect to the casting material. If necessary, provision can also be made to smooth the surface formed by the casting material, which can also have an advantageous effect on the flow of a heat exchange fluid within the corresponding heat exchanger box.

It is also possible, within the scope of the method according to the invention, to apply the casting material to the corresponding side of the tube sheet of the heat exchanger box or boxes in a layer thickness that is greater than the overhang of at least some, possibly all of the heat exchanger tubes, so that the post-processing serves exclusively or primarily for this purpose can, covered by the casting material tube openings of the heat exchanger tubes to expose.

Provision can preferably be made for the heat exchanger tubes to be inserted into the receiving openings of the tube sheet with a substantially equal overhang and for the potting material to be applied in a layer thickness which approximately corresponds to this overhang the effort for the post-processing of the layer of the casting material and/or the ends of the heat exchanger tubes can be reduced to a small extent.

In a particularly preferred embodiment of the method according to the invention, it can be provided that the surface formed by the casting material and/or the ends of the heat exchanger tubes are reworked in such a way that the entire surface of the casting material lies in one (preferably non-curved) plane, with in particular the end faces of the corresponding ends of the heat exchanger tubes can also be arranged in this plane (i.e. a flush transition is achieved between the free surface of the layer formed by the potting material and the end faces of the heat exchanger tubes). Such a heat exchanger can be distinguished not only by a particularly advantageous flow behavior for a heat exchange fluid within the heat exchanger box(es) and when flowing into or out of the heat exchanger tubes, but in particular also by simple post-processing.

In a further preferred embodiment of the method according to the invention, it can be provided that the casting material is cured before the post-processing. This can simplify the post-processing and, in particular, it can also be provided that this takes place by removing material, for example by grinding and/or milling. However, post-processing can also be carried out before the encapsulation material hardens, for example by spreading the encapsulation material in a flowable state, in particular with the aim of exposing pipe openings in the heat exchanger pipes previously covered by the encapsulation material and/or smoothing the free surface formed by the encapsulation material . Furthermore, post-processing of the potting material is also possible by means of non-cutting methods, for example by means of water jet cutting.

It can preferably be provided that a casting material is used which, after curing, has an essentially rigid or non-elastic state. Thermosetting plastics (e.g. “K-epoxy resin”) are suitable for this. A connection between the tube sheet(s) and the heat exchanger tubes using such a casting material can have a positive effect in particular on the structural strength of the heat exchanger and/or simplify post-processing, in particular post-processing that removes material. Alternatively, a potting material can also be used that has a defined elastic state after curing, so that it enables a thermally induced relative mobility between the tube plate(s) and the heat exchanger boxes in a defined manner while at the same time ensuring a sealed connection. For this purpose, for example, the use of thermoplastics can be provided as the casting material.

A heat exchanger can be manufactured according to a method according to the invention in a particularly simple and therefore cost-effective manner if, as is preferably provided, the heat exchanger tubes are connected to the tube plate of the or of the heat exchanger boxes are connected. However, there is also the possibility of additionally fixing the heat exchanger tubes to the tube sheet by other measures, for example by welding, soldering or gluing. This can be useful, for example, to ensure correct positioning of the heat exchanger tubes with respect to the tube sheet during the application of the potting material. Since the heat exchanger tubes in the receiving openings of the tube sheet are to be sealed exclusively or at least primarily by means of the potting material, these alternative connection measures can be provided in a simplified form in such a way that they cannot ensure an adequate sealing effect. As a result, the additional effort for the supplementary connection measures and consequently the production effort within the scope of a method according to the invention can be kept within acceptable limits overall.

An essential advantage of applying the casting material on the side of the tube sheet facing the protruding ends of the heat exchanger tubes is the good accessibility, because this is not impeded by the heat exchanger tubes themselves. Such accessibility can be particularly advantageous if the heat exchanger box or boxes are designed at least in two parts and, in addition to a tube plate, also have at least one housing which, within the scope of a method according to the invention, can only be accessed after the free surface of the layer formed by the casting material and/or the Ends of the heat exchanger tubes are connected to each other. Such a connection of the tube sheet to the housing of the (respective) heat exchanger box can be achieved, for example, using mechanical connecting means, for example snap-in connections or positively acting connections to be formed by reshaping tion elements, in particular using a sealing element arranged between the tube sheet and the housing. Equally advantageously, the tube sheet can be connected to the housing in a cohesive manner, in particular by gluing, welding or soldering.

The good accessibility of that side of the tube sheet to which the casting material is applied, and thus also of the layer formed from the casting material with the ends of the heat exchanger tubes embedded therein, can also advantageously make it possible to embed the heat exchanger tubes and also the layer of the casting material itself to check possible gaps and thus potential leaks in the operation of the heat exchanger and, if such gaps are found, to close them by further post-processing. Accordingly, in a preferred embodiment of the method according to the invention, it can be provided that at least the connection of the casting material to the heat exchanger tubes and/or the tube sheet is checked for leaks and leaky points are subsequently sealed.

In a particularly advantageous manner, the method according to the invention also enables a relatively simple and therefore inexpensive production of a microchannel heat exchanger, in which a large number (for example at least 1000, optionally also at least 10,000) heat exchanger tubes are inserted into associated receiving openings in the tube plate of the (each) heat exchanger box and fixed therein in a sealed manner must be, because such sealing and fixing by applying the casting material can be done collectively and not individually for the individual heat exchanger tubes.

Such a microchannel heat exchanger can be characterized in that the largest cross-sectional dimension (in the case of a preferably provided circular cross-sectional shape: the diameter) of the receiving openings is a maximum of 2 mm, preferably a maximum of 1 mm. The largest external cross-sectional dimension of the heat exchanger tubes (at least in the end sections intended for insertion into the receiving openings) should preferably be only slightly smaller than that of the receiving openings, with the cross-sectional shapes of the receiving openings and the (end sections of) the heat exchanger tubes preferably being identical in order to on the one hand to ensure relatively easy insertion of the heat exchanger tubes into the receiving openings and on the other hand to keep the gaps formed between the heat exchanger tubes and the surfaces of the tube sheet delimiting the receiving openings as small as possible, which can have an advantageous effect on the sealing of these gaps. A step within the scope of the method according to the invention can therefore also be the introduction of appropriately dimensioned receiving openings in the tube sheet of the (each) heat exchanger box and the provision of appropriately dimensioned heat exchanger tubes.

A microchannel heat exchanger, as is preferably produced within the scope of a method according to the invention, can also be characterized in that the heat exchanger tubes are not connected to one another by so-called fins

The indefinite articles (“a”, “an”, “an” and “an”), particularly in the claims and in the description generally explaining the claims, are to be understood as such and not as numerals. Components specified accordingly are therefore to be understood in such a way that they are present at least once and can be present several times.

• 1: Komponenten eines herzustellenden Wärmetauschers nach einem ersten Schritt eines erfindungsgemäßen Verfahrens zur Herstellung des Wärmetauschers;
• 2a: die Komponenten des herzustellenden Wärmetauschers nach einem zweiten Schritt eines erfindungsgemäßen Verfahrens zur Herstellung des Wärmetauschers;
• 2b: die Komponenten des herzustellenden Wärmetauschers nach einem zu dem Schritt gemäß der 2a alternativen Schritt eines erfindungsgemäßen Verfahrens zur Herstellung des Wärmetauschers;
• 3: die Komponenten des herzustellenden Wärmetauschers nach einem dritten Schritt eines erfindungsgemäßen Verfahrens zur Herstellung des Wärmetauschers; und
• 4: die Komponenten des Wärmetauschers nach einem vierten Schritt eines erfindungsgemäßen Verfahrens zur Herstellung des Wärmetauschers.

The present invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawings. The drawings show, each in a schematic representation:

• 1 : Components of a heat exchanger to be produced according to a first step of a method according to the invention for producing the heat exchanger;
• 2a : the components of the heat exchanger to be produced after a second step of a method according to the invention for producing the heat exchanger;
• 2 B : The components of the heat exchanger to be produced according to a to the step according to 2a alternative step of a method according to the invention for producing the heat exchanger;
• 3 : the components of the heat exchanger to be produced after a third step of a method according to the invention for producing the heat exchanger; and
• 4 : the components of the heat exchanger according to a fourth step of a method according to the invention for the production of the heat exchanger.

the 1 shows components of a heat exchanger to be produced by means of a method according to the invention. These components are a tube sheet 10, which is part of a multi-part heat exchanger box 14 of the heat exchanger to be produced (cf. 4 ) will show, as well as sections of a plurality of heat exchanger tubes 12. The heat exchanger tubes 12 have both a (constant over the longitudinal extent) circular inner and outer cross-sectional contour and are in receiving openings circular in cross section, which are introduced into the tube sheet 10 in a previous method step were, been plugged in. The heat exchanger tubes 12 were inserted so far that their ends assigned to the tube plate 10 protrude in relation to this tube plate 10 .

In the drawings, only one tube plate 10 or heat exchanger box 14 and only one section of the heat exchanger tubes 12 are shown. However, the heat exchanger should have two heat exchanger boxes 14 and consequently also two tube sheets 10, with the two ends of the heat exchanger tubes 12 each opening into one of the heat exchanger boxes 14 and for this purpose being inserted into receiving openings in the associated tube sheets 10. The structural design of the heat exchanger box, not shown, and its production corresponds to that of the heat exchanger box 14 shown.

After the heat exchanger tubes 12 have been inserted into the receiving openings of the tube sheets 10, that side of the tube sheets 10 which faces the protruding ends of the heat exchanger tubes 12 is coated with a casting material 16. Provision can be made, for example, for the potting material 16 to be applied to the corresponding side of the tube sheets 10 in a layer thickness that is greater than the overhang of the ends of the heat exchanger tubes 12 in relation to the tube sheets 10, which at least partially overlaps the ends of the Heat exchanger tubes 12 limited tube openings 18 results, as in the 2a is shown. Alternatively, however, there is also the possibility of applying the potting material 16 to the corresponding side of the tube sheets 10 in a layer thickness that is smaller than the overhang of the ends of the heat exchanger tubes 12 with respect to the tube sheets 10, from which initially the ends of the heat exchanger tubes 12 overhang with respect to the layer resulting from the potting material 16 (cf. 2 B ).

The casting material 16 is then cured, as a result of which the heat exchanger tubes 12 are connected to the tube sheets 10 in a sealing manner. Such curing can be accelerated, for example, by influencing the temperature by supplying thermal energy.

The ends of the free surfaces of the layers formed from the casting material 16 and/or the ends of the heat exchanger tubes 12 are then reworked. This reworking is preferably carried out by removing material, for example by grinding or milling, and is due to the good accessibility of the layers formed from the casting material 16 and the ends of the heat exchanger tubes 12 embedded therein are relatively simple and therefore inexpensive. The aim of the post-processing is to achieve free surfaces that are as smooth as possible and lie in one plane for the layers formed from the casting material 16, with the end faces of the corresponding ends of the heat exchanger tubes 12 also being arranged flush with the free surfaces of the associated layers of the casting material 16 should be (cf. 3 ). On the one hand, this should ensure good integration of the heat exchanger tubes 12 into the casting material 16 and thus good structural strength and good sealing of the connection of the heat exchanger tubes 12 to the heat exchanger boxes 14 that are still to be completed. On the other hand, the aim is to achieve the lowest possible flow resistance for a flow of a heat exchange fluid when it flows over between the heat exchanger tubes 12 and the heat exchanger boxes 14 .

The post-processing of the layers of the casting material 16 and/or the ends of the heat exchanger tubes 12 can be followed by a leak test, in which it is checked to what extent the finished heat exchanger is leaking heat exchange fluid into the environment via the connections between the tube sheets 10 and the heat exchange tubes 12 formed by potting the ends of the heat exchange tubes 12 in the potting material 16. If points are determined at which such leaks occur, they can be reworked, for example by filling the corresponding gaps with the same potting material 16 that was also used for coating the tube sheets 10, or with a different filling material. This post-processing is also relatively easy due to the good accessibility of the layers of the casting material 16 and the ends of the heat exchanger tubes 12 embedded therein.

After a complete tightness of the connections between the tube sheets 10 and the heat exchanger tubes 12 could be determined, in a final method step, a housing 20 of the heat exchanger boxes 14 can be connected to the associated tube sheet 10 in order to complete the two heat exchanger boxes 14 (cf. 4 ). In this case, it can be provided, for example, that one of the housings 20 has an inlet 22 for a heat exchange fluid which is intended to flow through the heat dew schers is provided forms, while the other housing 20 has an outlet for this heat exchange fluid.

Reference List

10

tube sheet

12

heat exchanger tube

14

heat exchanger box

16

potting material

18

pipe opening

20

Housing

22

inlet

Claims (10)

Method for producing a heat exchanger, which has a heat exchanger box (14) forming an inlet (22) and/or an outlet as well as a tube plate (10) and a plurality of heat exchanger tubes (12), the ends of which are each inserted into a receiving opening of the tube plate (10). and fixed therein in a sealed manner, wherein the heat exchanger tubes (12) are pushed into the receiving openings to such an extent that their ends form a protrusion from the tube sheet (10), and then the tube sheet (10) rests on the protruding ends of the heat exchanger tubes ( 12) is coated with a potting material (16) on the side facing, characterized in that the free surface formed by the potting material (16) and/or the ends of the heat exchanger tubes (12) is/are post-processed in order to prevent the heat exchanger tubes (12) from protruding to reduce or remove the casting material (16) and/or to remove pipe openings (18 ) of the heat exchanger tubes (12) to expose. procedure according to claim 1 , characterized in that the potting material (16) is cured before post-processing. procedure according to claim 1 or 2 , characterized in that the post-processing takes place in a material-removing manner. Method according to one of the preceding claims, characterized in that the post-processing is carried out without cutting. Method according to one of the preceding claims, characterized in that the heat exchanger tubes (12) are connected to the tube sheet (10) exclusively by means of the casting material (16). Method according to one of the preceding claims, characterized in that the post-processing is carried out in such a way that the end faces of the heat exchanger tubes (12) end flush with the free surface of the casting material (16). Method according to one of the preceding claims, characterized in that a housing (20) of the heat exchanger box (14) is connected to the tube plate (10) after the free surface of the casting material (16) and/or the ends of the heat exchanger tubes (12) have been reworked . Method according to one of the preceding claims, characterized in that the connection of the casting material (16) to the heat exchanger tubes (10) and/or the tube sheet (10) is checked for leaks and leaks are subsequently sealed. Method according to one of the preceding claims for the production of a microchannel heat exchanger. Use of a heat exchanger for a motor vehicle produced by a method according to any one of the preceding claims.

Images