WO2012059231A1

WO2012059231A1 - Heat exchanger

Info

Publication number: WO2012059231A1
Application number: PCT/EP2011/005551
Authority: WO
Inventors: Laurentino Oskar Cabero
Original assignee: Cabero Wärmetauscher Gmbh & Co. Kg
Priority date: 2010-11-06
Filing date: 2011-11-03
Publication date: 2012-05-10
Also published as: EP2635389A1; DE202010015200U1

Abstract

The invention relates to a heat exchanger which comprises a plurality of heat exchanger tubes (1) through which a medium can flow and which extend substantially in parallel to each other, at least two heat exchanger tubes each fluidically communicating with each other at their ends by means of a tube bend (4) through which a medium can flow. Said tube bends (4) are connected to each of the heat exchanger tubes (1) by means of an adhesive joint (5), the tubular bend (4) and the heat exchanger tube (1) overlapping each other in the region of connection by virtue of an inner tube section (6) being inserted in an outer tube section (7). An annular cavity (10) which is mainly filled with adhesive (9) is configured in the respective region of overlap (8) between the inner tube section (6) and the outer tube section (7), the cavities (10) being axially delimited by regions in which the respective inner and outer tube section (6; 7) rest against each other.

Description

heat exchangers

The present invention relates to a heat exchanger having a plurality of heat exchanger tubes through which at least substantially parallel to each other and are preferably connected at its surface with heat transfer elements, wherein each two heat exchanger tubes end by means of a

flow-through pipe bend are fluidly connected together.

Such heat exchangers are well known in a variety of designs and in various different applications in use.

Due to favorable properties, in particular with regard to

Durability, processability and heat transfer, the heat exchanger tubes and the pipe bends are usually made of copper, wherein the heat exchanger tubes and the pipe bends are typically soldered together. Such a kind of construction generic

Heat exchanger has proven in practice in the sense, as in this way durable solid and dense connections of the

Heat exchanger tubes and pipe bends can be produced with each other. However, such heat exchangers are due to the

Commodity price of copper associated with manufacturing costs, which lead to efforts in the search for more cost-effective, but technically at least substantially equivalent solutions.

In this sense, it is proposed in DE 1525743 A to produce tube coils used in the field of cooling technology by gluing together aluminum pipe sections and pipe bends. In this case, an adhesive applicator is used, which receives the end of the respective pipe section, which is the

Plug-in part of the pipe joint forms. A viscous adhesive is forced through the applicator, which is the

Adhesive ström limited and directed to predetermined, located on the surface of the pipe sections bodies. The pipe section is then removed from the applicator and that with adhesive

CONFIRMATION COPY coated end in the receiving part or sleeve part of the

Pipe connection inserted. After assembling the cooling coil and not yet cured adhesive is a suction on the

Cooling coil brought to action.

In practice, this type of production of generic heat exchangers has not been successful; because the connections between the pipe sections and the pipe bends do not meet the high demands on the mechanical strength and tightness, especially with strongly changing temperatures was not sufficiently durable.

This results in the present invention underlying task, which consists of a comparatively

cost-effective, in terms of performance characteristics of the well-established state of the art with brazed copper tubes at least in

To provide substantially equivalent heat exchanger of the type mentioned.

The object specified above is achieved by a heat exchanger of the type mentioned above with the following

Characteristics:

the pipe bends are associated with the two respectively

Heat exchanger tubes connected by means of an adhesive connection;

in the region of their connection, each of the pipe bend and the heat exchanger tube overlap each other by immersing an inner pipe section in an outer pipe section;

in the respective overlap area is between the inner

Pipe section and the outer pipe section an annular, at least predominantly filled with adhesive cavity executed; the cavities are axially limited by areas in which the respective inner and outer pipe sections abut each other.

In combination with each other, the above-mentioned features ensure the possibility of producing a powerful, durable reliable heat exchanger of the generic type at extremely attractive cost, which contributes to the fact that due to the

specific inventive design of the compounds of the heat exchanger tubes and the pipe elbows with each other, the Heat exchanger tubes can be made of a less expensive material than copper (especially aluminum), without this, the effect on the function and life of the heat exchanger adversely affected. In view of the longevity and reliability is of importance that between the respective parts to be joined together, ie the heat exchanger tube and the pipe bend, in the overlap region, an annular cavity, the

axially on both sides by regions in which the heat exchanger tube and the pipe bend abut each other is limited and can be filled in the adhesive after the two said parts have been inserted into one another. In this way, that is excluded that adhesive, which - according to the prior art - before the

Merging was superficially applied to one of the two parts, is staked when mating, resulting in a

Weak spot in the bond leads. Due to the filling of the respective annular cavity in the overlap region of

Heat exchanger tube and elbow after the mating of the two parts, it is also possible in particular numerous parts from which the heat exchanger in question is constructed,

zusammenzustecken, before then, particularly preferably for all relevant connectors simultaneously, the annular

Cavities in the range of the variety of connectors with

Adhesive are filled. By in such a procedure numerous - possibly even all - connectors of the

Heat exchanger before - by subsequent bonding taking place - fixation can be made, manufacturing tolerances of the items (including those of the heat transfer plates or other heat transfer elements) are taken into account or compensated only in mated, not yet bonded structure, so that the bonds caused by the subsequent filling of the

annular cavities are formed with adhesive, themselves are stress-free. In this way, heat exchangers can be realized in which the heat exchanger tubes and pipe elbows, without being soldered together, are permanently sealed together. This in turn allows the use of a difficult or impossible solderable material, in particular for the heat exchanger tubes, which in the context of the present invention is preferably used in that the heat exchanger tubes are made of aluminum.

According to a first preferred embodiment of the invention, the inner and the outer tube section are free of play in the two abutment regions axially delimiting the respective annular cavity, preferably with a defined fit against one another. This is because it ensures the exact positioning of the pipe sections to each other during assembly, in manufacturing technology

Advantages. Moreover, it is also favorable in terms of reliability and service life of the heat exchanger, because in this way can be realized particularly homogeneous, concentric bonding of the pipe sections with uniform adhesive joints, which remain tension-free even at varying temperatures to a considerable extent.

It is particularly advantageous if, in the overlapping region, the outer tube section has two conical sections which widen in the direction of the center of the annular cavity

having. In this embodiment, the cavities serving to receive the adhesive are formed by the special shape of the respective outer tube section, while the respective inner tube sections can be made cylindrical in the overlapping region. This is advantageous in terms of flow, wherein at the same time the conical design of the outer pipe section on both sides in the overlapping area is advantageous with regard to a durable mechanical strength and tightness of the adhesive bond.

According to another preferred embodiment of the invention, at least one opening provided in the outer pipe section opens into the cavity. Through this can at

assembled tube sections adhesive are filled in the cavity described above. Particularly preferably, two such open into the cavity in the outer tube section

provided openings that can each other in particular substantially diametrically opposite. The opening facing the adhesive-filling opening serves to control the filling and the discharge of air and excess adhesive; this comes Namely because the risk of air bubbles is significantly reduced, the quality of the adhesive joints benefit. In

From a procedural point of view, it is particularly advantageous if the adhesive is filled from below, through a lower opening in said cavity and the air initially in the cavity by an opposite, that is. overhead

Control opening displaced.

According to yet another preferred embodiment of the invention, it is provided that the outer pipe section end one

Has widening. This in turn is of particular advantage with regard to a simple assembly of - in a second step to be glued - connectors. Preferably, in the outer tube section between the widening and the beginning of the cavity, a cylindrical tube section whose axial length particularly preferably at least 25% of the diameter of the

cylindrical pipe section amounts. Again, this is an advantageous aspect in terms of production engineering, because the cylindrical pipe section when mating the two

Pipe sections the inner leads.

For certain applications (eg high-pressure applications) may be advantageous in individual cases, if in each case in the

Overlap areas of heat exchange tubes and pipe bends two or more filled with adhesive annular cavities of the

above-described design are provided in axial sequence. Such a juxtaposition of several adhesive chambers opens up the possibility to optimize these individual function specific, so that the adhesive chambers in particular not

must be identical to each other. On the contrary, it is quite favorable to optimize an adhesive chamber with regard to the seal between the heat exchanger tube and pipe bend, the other adhesive chambers on the other hand in terms of the extent

mechanical skill of connecting said parts. The function-specific optimization can relate both to the design of the adhesive material to be filled annulus, as well as the selection of adhesives. Although in the context of the present invention is basically also considered that the respective outer pipe sections of the connecting portions are formed on the heat exchanger tubes, it proves to be advantageous both in terms of cost-effective production of the components as well as in terms of ease of installation, if the pipe bends each two outer

Pipe sections are executed, i. the heat exchanger tubes

each end are inserted into the associated pipe bends.

As far as the choice of material for the elbows is concerned, these exist in particular when the heat exchanger tubes are made of aluminum, particularly preferably also made of aluminum. This is advantageous because in this case the heat exchanger tubes and the tube bends have the same thermal expansion properties, which benefits the life of the bonds. However, in the context of the present invention, the pipe bends may well also be made of a different material, for example of plastic. This is advantageous if in the area of the pipe bends targeted heat transfer to the environment should be prevented as much as possible.

Heat exchangers according to the present invention can be with

Use advantage on a wide range of applications. The above-mentioned favorable properties come into play in a special way when using the corresponding heat exchanger as a recooler for water, water-glycol and oil as well as a condenser for various refrigerants including NH ₃ .

By means of the present invention explained above, not only can the use be carried out accordingly

less expensive materials for the production of

Heat exchanger tubes - achieve cost advantages over the prior art. Also, the greater flexibility in terms of the materials used to make the heat exchanger tubes and bends is an important aspect. Because the inventive design of the compounds of the heat exchanger tubes and the pipe bends with each other leaves specific, f-optimized

Material pairings in which metals (non-ferrous metals, iron, Steels, including stainless steel) and non-metallic materials can be used.

In the following, the present invention is explained in more detail with reference to a preferred embodiment illustrated in the drawing, wherein the drawing shows the edge region of a heat exchanger according to the present invention in the cutout region with four ends of a package of heat transfer plates

outstanding, by means of two pipe bends interconnected heat exchanger tubes shows.

The heat exchanger shown in the drawing comprises a

Variety of mutually parallel flow-through heat exchanger tubes 1, of which, however, only four are shown in the drawing, and a plurality of - also parallel to each other at a distance - orthogonal to the

Heat exchanger tubes 1 arranged heat transfer elements 2 in the form of heat transfer plates 3. The latter are connected in a manner known as such with the heat exchanger tubes 1 at the surface of heat-conducting. In each case two heat exchanger tubes 1 are at the end by means of a flow-through pipe bend. 4

fluidically interconnected. Since the heat exchanger according to the drawing corresponds to the well-known state of the art (see DE, for example, DE 1525743, FIG

Explanations dispensable.

The existing aluminum pipe bends 4 are associated with the two respectively, also made of aluminum

Heat exchanger tubes 1 by means of an adhesive connection 5 tightly and mechanically firmly connected. For this purpose, each overlap the pipe bend 4 and the heat exchanger tube 1 in the region of their connection to each other by an inner pipe section 6, in this

Embodiment is carried out on the relevant heat exchanger tube 1, in an outer tube section 7, the

Accordingly, in this case formed on the pipe bend 4, immersed. In the respective overlap region 8 between the inner pipe section 6 and the outer pipe section 7 is an annular, at least predominantly filled with adhesive 9 cavity 10th executed, which is axially bounded on both sides by areas in which the respective inner pipe section 6 and outer pipe section 7 rest against each other without play. in view of the fact that in each case the heat exchanger tube 1 (also) is made cylindrical in the overlap region 8 with its nominal dimensions, the cavities 10 by a specific, explained in detail below end-side expansion of

Pipe bend 4 defined. For this purpose, the first increases

Diameter of the pipe bend 4 each in a transition region 11 such that its inner diameter corresponds to the outer diameter of the heat exchanger tube 1. With these measurements, a first cylindrical portion 12 of the pipe bend in

Overlap area 8 executed. This is followed by a cavity 10 limiting, widening first cone portion 13, which merges into a more or less cylindrical central portion 14. The latter is followed by a further limiting the cavity 10 second, tapered cone portion 15, which merges into a cylindrical guide portion 16, whose

Inner diameter, in turn, the outer diameter of the

Heat exchanger tube 1 corresponds. Finally, the outer tube section 7, i. in this case, the pipe bend 4 at the end of a widening 17.

In the cavity 10 in each case two provided in the outer tube section 7, substantially diametrically opposite openings open, namely a - during installation of the heat exchanger below - filling opening 18 and a - during assembly overhead - control opening 19th

The essential steps in the manufacture of the illustrated in the drawing heat exchanger are:

Assembling the heat transfer plates 3 and the

Heat exchanger tubes 1 to a heat exchanger block;

Placing the pipe bends 4 on the respective free ends of the

Heat exchanger tubes; Filling the between the heat exchanger tubes 1 and the pipe bends 4 in the respective overlapping areas 8 existing cavities 10 with adhesive. 9

Claims

claims

Heat exchanger with a plurality of through-flow

Heat exchanger tubes (1) to each other at least in

Run substantially parallel and are preferably connected at its surface with heat transfer elements (2), wherein each two heat exchanger tubes are fluidly connected to each other at the end by means of a flow-through pipe bend (4), with the following features:

the pipe bends (4) are connected to the two respectively associated heat exchanger tubes (1) by means of an adhesive connection (5);

in the area of their connection each overlap

Pipe bend (4) and the heat exchanger tube (1) each other by an inner pipe section (6) immersed in an outer pipe section (7),

in the respective overlap region (8) between the inner tube section (6) and the outer tube section (7) an annular, at least predominantly filled with adhesive (9) cavity (10) is executed;

the cavities (10) are bounded axially by regions in which the respective inner and outer pipe sections (6, 7) abut one another.

Heat exchanger according to claim 1, characterized in that the inner and the outer pipe section (6; 7) in the

Investment areas clearance, preferably with a defined fit abut each other.

Heat exchanger according to claim 1 or claim 2, characterized

in that, in the overlapping area (8), the outer pipe section (7) has two conical sections (13; 15) widening in the direction of the center of the cavity (10).

4. Heat exchanger according to one of claims 1 to 3, characterized in that in the cavity (10) at least one in the outer pipe section (7) provided opening (18) opens.

5. Heat exchanger according to claim 4, characterized in that in the cavity (10) two in the outer pipe section (7) provided openings (18, 19) open.

6. Heat exchanger according to claim 5, characterized in that the two openings (18, 19) each other substantially diametrically gegenüberl lie.

7. Heat exchanger according to one of claims 1 to 6, characterized

characterized in that the outer tube section (7) has an expansion (17) at the end.

8. A heat exchanger according to claim 7, characterized in that in the outer tube section (7) between the on to (17) and the beginning of the cavity (10) is a cylindrical tube section (16).

9. Heat exchanger according to claim 8, characterized in that the axial length of the cylindrical pipe section (16) is at least 25% of the diameter of the cylindrical pipe section.

10. Heat exchanger according to one of claims 1 to 9, characterized

in that the heat exchanger tubes and / or the

Pipe bends (4) made of aluminum.

11. Heat exchanger according to one of claims 1 to 10, characterized

characterized in that on the pipe bends (4) in each case two outer pipe sections (7) are executed.

12. Heat exchanger according to one of claims 1 to 11, characterized

characterized in that a plurality of annular cavities (10) filled at least predominantly with adhesive (9) are provided in axial sequence in the respective overlapping region (8).

13. Heat exchanger according to one of claims 1 to 12, characterized in that the cavities (10) designed functionally different and / or with different

Adhesive (9) are filled.

14. Heat exchanger according to one of claims 1 to 13, characterized

characterized in that the pipe bends (4) and the heat exchange tubes (1) consist of different materials.

15. A method of manufacturing a heat exchanger according to claim 1, comprising the following steps:

Assembly of heat transfer elements (2) and

Heat exchanger tubes (1) to a heat exchanger block;

Placing pipe elbows (4) on the respective free ends of the heat exchanger tubes,

Filling of between the heat exchanger tubes (1) and the

Pipe bends (4) in the respective overlapping areas (8) existing cavities (10) with adhesive (9).