WO2016041816A1 - Method for producing a heat exchanger - Google Patents

Abstract

The invention relates to a method for producing a heat exchanger, comprising a connection between two elements (2, 3) of a heat exchanger (1), said two elements (2, 3) being connectible to each other in at least one respective contact surface. An adhesive film (4) is applied to at least one of the elements (2, 3) in the region of the respective contact surface, the two elements (2, 3) being brought in contact with each other by applying pressure and an adhesive bond being produced between the elements (2, 3) by means of the adhesive film (4). The invention also relates to an associated heat exchanger (1).

Description

 Process for producing a heat transfer

description

Technical area

The invention relates to a method for producing a heat exchanger. Moreover, the invention relates to a heat exchanger.

State of the art

Heat exchangers are used to transfer heat between different fluids. For this purpose, heat exchangers of different types are known in the prior art.

Among the known types include, for example, heat exchangers in tube-fin construction, shell and tube heat exchangers or heat exchangers in stacking disc design. These heat exchangers have in common that they are flowed through by fluids and / or flow around and thus creates a heat transfer between the fluids involved. These known heat exchangers are used inter alia as intercooler, coolant radiator, oil cooler or as a radiator, etc. Heat exchangers are made of metallic and / or non-metallic materials which, for example, by means of soldering, welding, form-locking siger connection or bonding methods are interconnected. To the elements, which are joined together by soldering, welding or gluing, include, for example, tubes, plate elements, fin elements, tube sheets and cover elements, for connecting individual elements by means of a soldering process, either after the joining of the elements, a solder material can be applied or it can already a solder coated elements are used. Under the action of heat, the solder material is melted and by the subsequent solidification of the solder material, a permanent connection is produced,

DE 103 28 274 A1 discloses a method for producing a Schichtwärmeübertragers, wherein a plurality of plate elements are stacked and provided with a solder, This Plattenstapei is then fixed mechanically before finally the plate elements are welded together and / or soldered,

DE 10 2005 048 452 A1 discloses a heat exchanger in stacking disk construction, wherein the heat exchanger consists of a plurality of disk elements, which are stacked on each other. The disk stack is completed at the top and bottom by a base plate. The individual disk elements are soldered together and form within the disk stack flow channels, which are flowed through by one or more fluids.

Alternatively, individual elements can also be connected to one another by adhesive methods.

DE 10 2008 01 9 556 A1, for example, discloses a component acting as a heat exchanger, which component is produced from a stack of cohesively bonded plates. In addition, a method for producing the component is disclosed. The individual elements are acted upon for connection with a polymeric adhesive. Then they are pressed together until the adhesive has hardened. DE 102 28 697 A1 discloses a method for connecting a pipe made of metal with circumferential ribs of a non-ferrous MetafI as part of a heat exchanger. The ribs are connected to the tube by gluing.

A disadvantage of the devices and methods of the prior art, in particular, that for the fixation of the elements against each other for soldering and welding consuming frames must be made, which are each designed for a special heat exchanger. Furthermore, the racks must withstand the high temperatures during soldering or welding. The soldering operations for a heat exchanger often last several tens of minutes to several hours and are also very energy-intensive. In addition, the solder materials used are very expensive. In addition, before applying the soldering material, a cleaning of the surface is necessary. Following the soldering process, it may also be necessary to clean the heat exchanger in order to remove excess solder material. Soldering and welding processes are also not suitable for bonding any materials, which greatly limits the choice of materials for the elements of the heat exchanger and the possible combinations of materials. When using adhesives is disadvantageous that the adhesives must be applied consuming on the elements to be bonded, which can be done for example by spraying and / or spraying. Furthermore, the adhesive surfaces thus produced are either unevenly applied to the adhesive or it is applied a very large amount of the adhesive, since the layer thicknesses of the adhesives are partially above 2mm. As a result, the required curing time is increased, making the production more complex and cost intensive.

Presentation of the invention. Task, solution. advantages Therefore, it is the object of the present invention to provide a method for producing a heat exchanger, which is improved over the prior art. Moreover, it is the object of the invention to provide an advantageous heat exchanger. The object with regard to the method is achieved by a method having the features of claim 1.

An embodiment of the invention relates to a method for producing a heat exchanger with a connection between two elements of a heat transfer, wherein the two elements are connected to each other at least one contact surface, wherein at least one of the elements is acted upon in the region of the respective contact surface with an adhesive film in which the two elements are brought into abutment with the application of a compressive force and an adhesive bond between the elements is produced by the adhesive film.

It is particularly advantageous to use an adhesive film, as this is easy to handle and in a simple manner to the respective element or the contact surface between the elements is adaptable. The adhesive film can be applied manually or automatically to one of the elements. It may also be advantageous if the adhesive film is already applied to the starting material of the elements and the elements are subsequently produced using molding methods such as embossing, cutting or stamping.

Between the elements, an adhesive bond is advantageously produced by the adhesive film, which replaces the usual solder joint. The otherwise used solder material is thus replaced in this process by the adhesive film. This is particularly advantageous since the adhesive film can also be applied to impure surfaces, which may be exposed to fats, oils or dirt particles, for example. This can otherwise prevent the use of soldering drive usual step of cleaning and degreasing the surfaces of the elements may be omitted.

An adhesive film is furthermore particularly advantageous because it is particularly easy to produce very uniform and easily reproducible layer thicknesses. This is advantageous in particular with regard to an automated manufacturing process in the context of mass production.

It is also advantageous if the adhesive film is touch-dry, wherein the adhesive effect of the adhesive film is activated and / or becomes highly viscous by the application of a compressive force and / or by the heating of the adhesive film. A touch-dry or in technical language tack tack-free adhesive film is particularly advantageous because the handling of the adhesive film is much easier. No special precautions must be taken against touching the adhesive film on the elements during the process. The adhesive effect of the adhesive film is activated only by the application of a compressive force and / or by the heating and / or highly viscous, so that the adhesive effect is generated only during the process. This also facilitates the positioning of the elements relative to one another, since unintentional sticking is avoided. It is also preferable if the adhesive film has a layer thickness between 10pm and 250pm. A particularly thin adhesive film is particularly advantageous because the amount of material used can be kept very low. In particular, in comparison to conventional adhesive methods in which the adhesive is applied by means of a nozzle in beads, so a significantly reduced adhesive use can be achieved. The particularly thin layer thicknesses can be produced in particular by filler-free adhesives. In the connected state, the adhesive layer between the two elements is particularly thin and is preferably a few nanometers to about 250pm. Very thin layer thicknesses of the adhesive are also advantageous in order to produce very short curing times for the adhesive bonds. For thermoplastic adhesives Substances, the curing time may preferably be in a range of 1 minute to 20 minutes, Particularly preferred are curing times of less than 5 minutes to ensure the highest possible Prozessesempempo.

Moreover, it is advantageous if the adhesive film is laminated on one of the elements and / or inserted into a recess in one of the elements. For this purpose, the adhesive film can advantageously be adhesively bonded to one of the elements with the aid of a further adhesive or can simply be applied to this. By applying the pressure force and / or by heating, an adhesive bond with both elements is finally produced.

Furthermore, it is advantageous if the adhesive film is applied to one of the elements over the whole area in the area of the contact surface or that the adhesive film is applied to one of the elements in a tailor-made manner tailored to the respective contact surface.

Depending on the design of the elements and the actual contact surface between the elements to be joined, the adhesive film can be applied over the whole area to a region of an element or tailored specifically to the contact surface. Elements with voluminous adhesive film can be produced particularly easily in a scale suitable for mass production. Specially tailored adhesive films can further reduce material usage.

It is also expedient if a compressive force of 0.005 N / mm ² and 1 SN / mm ^{2 is} applied to the elements brought into contact with each other for connection. It is particularly advantageous if the pressure force is applied in a heated state. By heating the adhesive film is already softened, whereby a dipping of the elements in the adhesive layer is made possible.

Moreover, it is advantageous if the method comprises the following steps:

^■ coating at least one element with an adhesive film, ^{■ putting} the elements together,

^Applying a compressive force to the elements,

^■ heating of the elements and disposed in the contact surface Kiebstofffolie,

^■ cooling the elements and the adhesive foil,

 ■ checking the tightness of the connection created between the elements,

wherein the pellet film is softened by the heating, wherein the pellet film of at least one of the elements is at least partially displaced, whereby the layer thickness between the elements after heating is lower than before heating.

The method is particularly oriented to the already known method for soldering heat exchangers. In contrast to soldering but no solder material is applied, but only a Kiebstofffolie, which melts at much lower temperatures than the solder material. All connections between the elements of a heat exchanger, which have hitherto been produced by soldering, can also be produced by the proposed adhesive method.

In particular, different materials can be connected to one another in a simple manner. This is particularly advantageous in the case of materials which have greatly different length expansions upon exposure to temperature or materials which can act as a galvanic element due to the electrically conductive solder connection. The object with regard to the heat exchanger is achieved by a heat exchanger with the features of claim 8.

An embodiment of the invention relates to a heat exchanger with at least two elements, wherein the heat exchanger is produced by a method already described, wherein the elements through pipes and / or tube sheets and / or plate elements and / or cover elements and / or pipe sockets and / or

Rib elements are formed.

 By means of the adhesive method, all known types of heat exchangers can be produced. The adhesive film acts as a complete replacement for a solder used in soldering. The adhesive film can advantageously also be applied to strongly differently shaped elements, so that there are practically no geometric restrictions for the elements to be connected by means of the adhesive film.

Furthermore, it is expedient if the adhesive film is formed from an adhesive which consists of at least one component or only one component and can be filled or is free of filler. Suitable fillers here are thermally conductive flakes or particles. In this case, preferably materials such as boron nitride, aluminum, copper, steel, Mesung, graphite, etc. are used. A filler-free adhesive is particularly advantageous in order to produce the smallest possible layer thickness of the adhesive film.

It is also advantageous if the heat exchanger has at least one flow channel, which can be traversed by a fluid, wherein the flow channel is sealed against the environment by the arranged between the individual elements of the heat transfer adhesive film fluid-tight.

Through the adhesive connection flow channels can be generated in a simple manner, which are sealed at their interfaces to other elements of the heat exchanger by the adhesive bond produced. Also, the flow channel itself can be sealed by the adhesive bond, for example, by the flow channel is first generated by the bonding of two elements. The seal against the environment can be done, for example, at the junction between a pipe and a tube sheet, at the junction between two plate elements or the junction between a tube sheet and a collection box forming a lid member. It is also preferable if the heat exchanger has at least one tube _", wherein the tube is acted on at least one of its outwardly directed end portions with an adhesive film, wherein the area acted upon by the adhesive film is inserted into a recess of a tube sheet and the adhesive film, the contact surface is at least partially covered between the tube and the tubesheet and forms a fluid-tight seal between the tube and the tubesheet.

Through the use of adhesive films to produce the connections between the elements of a heat exchanger, a heat exchanger in pipe-fin construction or a Rohrbündeiwärmeübertrager can be produced inter alia advantageously. It is particularly advantageous that elements of different materials can be connected to one another by the adhesive connection. Thus, for example, the tubes may be formed of a metallic material with a high thermal conductivity, while the tubesheet is formed, for example, from a plastic, which has particularly good properties in terms of the absorption of resulting forces. Through the use of adhesive films compounds can be produced with a high density. Due to the particularly low layer thickness of the adhesive film, the elements can be mounted similar to the solder-plated elements in a soldering process.

Moreover, it is advantageous if the heat exchanger is formed from a plurality of stacked plate elements, wherein the plate elements are abutting each other at its edge region and in the contact area an adhesive film between the individual plate elements is arranged and forms a fluid-tight seal between the plate elements.

A heat exchanger in stacked disk design can be produced in a simple manner by the use of adhesive films. For this purpose, the plate elements have an adhesive film, in particular in their contact area relative to one another. Furthermore, it is advantageous if the heat exchanger has a collecting box, wherein the collecting box is formed from a tube plate and a lid member inserted into a receiving area of the tube plate, wherein in the receiving area of the tube plate an adhesive film is arranged, which the contact surface between the lid member and the tube sheet at least partially covered and forms a fluid-tight seal between the cover member and the tube sheet.

Such a heat exchanger is particularly advantageous because the collection box can be produced with the same connection method as the rest of the heat transfer. In this way, individual process steps during production can be saved, making the production easier and less expensive. Nevertheless, a uniform connection quality can be generated at the various connection points. It is also expedient if the heat exchanger has at least one tube which can be flowed through by a first fluid and by a second fluid, wherein at least one rib element is provided on an outwardly directed surface of the tube and / or on an inwardly directed surface of the tube is arranged, which is connected by the adhesive film to the tube.

It is also particularly advantageous for rib elements to be connected to the tube inside the tube or to the outer surface of the tube using the adhesive film. This is particularly advantageous to allow for improved heat transfer. The low layer thicknesses of the adhesive film are particularly advantageous in order to produce the highest possible thermal conductivity.

Furthermore, it is expedient if the adhesive film is destructible under the action of heat. This is particularly advantageous in order to be able to disassemble the heat exchangers generated after their use in a simple manner and to be able to feed the individual materials used to a recycling cycle. The required temperature level for the destruction of the adhesive layer is preferably clearly above the temperature level, which occurs in regular operation of the heat exchanger. Nevertheless, the required temperature level is well below the temperature level, which is needed to produce a solder joint.

Solder joints are produced at temperatures of about 650 ° C. The temperature required for the destruction of the adhesive film is significantly below this temperature level. The melting of the adhesive film can preferably take place in a temperature range from about 100.degree. C. to about 380.degree. The temperature sufficient to destroy the adhesive film is therefore preferably above the melting temperature of the adhesive film and below the usual soldering temperature.

Moreover, it is advantageous if the heat exchanger is made of metallic materials and / or of non-metallic materials.

This is advantageous because, in particular, combinations of different materials are also made possible. Here, for example, materials with very different coefficients of thermal expansion can be used, since the temperatures required to produce the connection are well below the temperatures that occur during a soldering process. This leads to a better sealing effect at the joints, since the heat-induced stresses in the heat exchanger turn out to be significantly lower.

The preferably used non-metallic materials include in particular plastics or activated carbon. The metallic materials include, in particular, copper, aluminum, steel and titanium. Furthermore, it is particularly advantageous that the use of adhesive films can also be used to bond materials which can not be joined together by means of ordinary soldering methods. This significantly increases the variety of available materials. Furthermore, it is preferable if the adhesive sheet is formed of a thermoplastic material. A thermoplastic material is particularly advantageous because it is very environmentally friendly compared to other adhesives and is easily recyclable. In addition, for thermoplastic adhesives, only minimal minimum storage and processing requirements must be met. For example, no air evacuation must be provided when processing thermoplastic adhesives, since they do not or only to a very small extent outgas. Since it is not an hazardous substance, the adhesives or parts coated with an adhesive can also be stored with little safety precautions. A thermoplastic material is also advantageous because it has high media resistance, which increases the life and reliability of the component produced. This is particularly advantageous, in particular with regard to the partially corrosive media in the heat exchangers. It is furthermore particularly advantageous if all connections between the individual elements of the heat exchanger are produced using the adhesive film. This makes uniform processing possible and allows a manufacturing process that is very similar to the ordinary production process of soldered heat exchangers. This makes it easier to adapt an existing production plant to the new technology.

Furthermore, at least partially produced by a soldering process elements can be integrated into the otherwise bonded heat exchanger. Since the soldering temperatures are well above the temperatures for producing an adhesive bond, already soldered elements are not damaged during the gluing process.

Advantageous developments of the present invention are described in the subclaims and in the following description of the figures. Brief description of the drawings

In the following the invention will be explained in detail by means of embodiments with reference to the drawings. 1 is a sectional view through a tube of a heat exchanger and a corrugated fin member, wherein the corrugated fin member is bonded to the outer surface of the tube by means of an adhesive film, and FIG. 2 is a block diagram for explaining the method of manufacturing a heat exchanger.

Preferred embodiment of the invention

FIG. 1 shows a sectional view through a heat exchanger 1. The heat exchanger 1 has a tube 2, to which a rib element 3 is connected. The rib element 3 is connected by means of an adhesive layer 4 to the tube 2, wherein the adhesive layer 4 is formed by an adhesive film 4, which is arranged on the outer surface of the tube 2.

The adhesive film 4 may be laminated on the tube 2, so be connected with the aid of an adhesive to the tube 2, or simply be placed on the outer surface of the tube 2.

The rib element 3 is formed in Ausführungsbeispiei of Figure 1 by a corrugated fin element 3. In alternative embodiments, other fin elements may be provided to increase the outer heat transfer surface area of the tube. FIG. 1 shows only a limited partial view of the heat exchanger 1. By way of the elements depicted in FIG. 1, the heat exchanger 1 can also have further tubes and rib elements. Also, the tubes can advantageously be added end to end in tube sheets and / or collection boxes. FIG. 1 shows a state in which the rib element 3 rests on the adhesive film 4. For connection, the adhesive film 4 is heated, whereby it melts. Since a compressive force acts on the tube 2 and the fin element 3 at the time of heating, part of the adhesive film 4 is displaced by the rib element 3 and / or the tube 2, whereby the layer thickness of the adhesive film 4 is reduced.

FIG. 2 shows a block diagram to illustrate the method used to produce a heat exchanger. In block 20, the adhesive film is applied to at least one of the elements to be bonded together. This can be done by an automated process or manually. The adhesive film can in particular be laminated or inserted into a recess of an element. In block 21, the elements are brought into abutment with each other. For this purpose, they are positioned relative to each other according to the later desired appearance of the heat exchanger. Here, either only two elements can be positioned against each other or it can be made analogous to the known soldering a complete arrangement of all the heat exchanger block or the heat exchanger forming elements.

In block 22, a compressive force is applied to the relatively arranged elements. This can preferably be done in a device designed for this purpose. In block 23, the elements and the adhesive film are heated, whereby melting of the adhesive film is achieved. The elements are maintained at a predetermined temperature level for a predetermined period of time to allow for placement of the elements into the layer of adhesive film and ultimately to ensure curing of the adhesive layer.

Subsequently, in block 24, the cooling of the elements. In the subsequent block 25, the leak test of the components produced takes place. If necessary, this also requires a necessary rework. The embodiment shown in Figure 1 is exemplary and shows a section of a heat exchanger in tube-fin construction. The exemplary embodiment has no restrictive character, in particular with regard to the applicability of the method to a specific heat exchanger. The block diagram of FIG. 2 is merely exemplary and does not exclude alternative solutions and variations.

Claims

claims 1 . A method for producing a heat exchanger with a connection between two elements of the heat exchanger (1), wherein the two elements (2, 3) at each at least one contact surface are connected together bar, characterized in that at least one of the elements (2, 3) in Area of the respective contact surface with an adhesive film (4) is applied, wherein the two elements (2, 3) are brought together by applying a compressive force in abutment and by the adhesive film (4) an adhesive bond between the elements (2, 3) is generated , 2. The method according to claim 1, characterized in that the adhesive film (4) is touch-dry, wherein the adhesive effect of the adhesive film (4) by the application of a compressive force and / or by the heating of the adhesive film (4) is generated. 3. The method according to any one of the preceding claims, characterized in that the adhesive film (4) has a layer thickness between 10um and 250pm. 4. The method according to any one of the preceding claims, characterized in that the adhesive film (4) on one of the elements (2, 3) laminated and / or in a recess in one of the elements (2, 3) is inserted. 5. The method according to any one of the preceding claims, characterized in that the adhesive film (4) over the entire surface in the area of the contact surface on one of the elements (2, 3) is applied or that the adhesive film (4) tailored to fit the respective contact surface on a the elements (2, 3) is applied. 6. The method according to any one of the preceding claims, characterized in that applied to the abutting elements (2, 3) for connection a compressive force of 0.005N / mm ² and 15M / mm ² , 7. The method according to any one of the preceding claims, wherein the method comprises the following steps:  Coating at least one element (2, 3) with an adhesive film (4)  • bringing the elements (2, 3) into contact with each other,  8 applying a compressive force to the elements (2, 3), ^«Heating of the elements (2, 3) and arranged in the area of contact adhesive film (4), ^■ cooling of the elements (2, 3) and the adhesive film (4), ^■ checking the tightness of the connection created between the elements (2, 3),  characterized in that the adhesive film (4) is softened by the heating, wherein the adhesive film (4) of at least one of the elements (2, 3) is at least partially displaced, whereby the layer thickness between the elements (2, 3) after heating less than before heating. 8. Heat exchanger (1) with at least two elements (2, 3), wherein the heat exchanger (1) is produced by a method according to at least one of the preceding claims, characterized in that the elements (2, 3) through tubes (2) and / or tube sheets and / or plate elements and / or cover elements and / or pipe sockets and / or rib elements (3) are formed. 9. heat exchanger (1) according to claim 8, characterized in that the Adhesive film (4) is formed from an adhesive which consists of at least one component or of only one component and is filler-free or provided with fillers. 10.Wärmeübertrager (1) according to one of the preceding claims 8 to 9 _»that the heat exchanger (1) has at least one flow channel which is flowed through by a fluid, wherein the flow passage from the environment through the (between the individual elements 2 , 3) of the heat exchanger (1) arranged adhesive film (4) is sealed fluid-tight. 1 1 .Wärmeübertrager (1) according to any one of the preceding claims 8 to 10, characterized in that the heat exchanger (1) has at least one tube (2), wherein the tube (2) on at least one of its outwardly directed end portions with an adhesive film (4) is acted upon, wherein the area acted upon by the adhesive film (4) is inserted into a recess of a tube bottom and the adhesive film (4) at least partially covers the contact surface between the tube (2) and the tube bottom and a fluid-tight seal between forms the tube (2) and the tube sheet. 12. Heat exchanger according to one of the preceding claims 8 to 1 1, characterized in that the heat exchanger is formed of a plurality of stacked plate elements, wherein the plate elements are at their edge region in abutment and arranged in the investment area an adhesive film between the individual plate elements is and forms a fluid-tight seal between the plate elements. 13. Heat exchanger (1) according to one of the preceding claims 8 to 12, characterized in that the heat exchanger (1) has a collecting box, wherein the collecting box is formed from a tube plate and a lid inserted into a receiving area of the tube element, wherein in an adhesive film is arranged in the receiving region of the tubesheet, which at least partially covers the contact surface between the lid member and the tubesheet and forms a fluid-tight seal between the lid member and the tubesheet. 14, heat exchanger (1) according to any one of the preceding claims 8 to 13, characterized in that the heat exchanger (1) has at least one tube (2), which can be flowed through by a first fluid and a second fluid, wherein at one after at least one rib element (3) is arranged on the outside surface of the tube (2) and / or on an inwardly directed surface of the tube (2), which is connected to the tube (2) by the adhesive film (4). 5. Heat exchanger (1) according to one of the preceding claims 8 to 14, characterized in that the adhesive film (4) is destructible under the action of heat. 6. Heat exchanger (1) according to one of the preceding claims 8 to 15, characterized in that the heat exchanger (1) is made of metallic materials and / or non-metallic materials. 17. Heat exchanger (1) according to one of the preceding claims 8 to 16, characterized in that the adhesive film (4) is formed from a thermoplastic material.