EP1980812B1 - Heat exchanger with device for spacing heat exchanger pipes - Google Patents

Description

The invention relates to a heat exchanger according to the features in the preamble of patent claim 1.

From the DE 20 2006 012 164 U1 is a spacer for tube bundles in heat exchangers of a plurality of tubes with parallel, arranged in groups in parallel planes tubular axes, characterized in that the spacer is formed in two parts of a rigid material, which nestles on both sides tightly around the tubes of one of the parallel planes. The close contact between the spacer and the heat exchanger tube creates narrow gaps in which deposits and condensation products can form due to the passing heat exchanger medium, which can lead to corrosion, in particular crevice corrosion of the heat exchanger tube or the spacer. Also, the possibility of cleaning is limited by the flat contact of the spacers on the heat exchanger tubes.

The generic GB 1 591 784 discloses a heat exchanger and a series of strip-shaped spacers, the spacers having a top flange and a bottom flange. Between the upper chords and the lower chords, the heat exchanger tubes are arranged, wherein the heat exchanger tubes in a direction of the tube axis of the Heat exchanger tubes extending line contact and / or point contact with the upper flange and the lower flange. Free spaces are present between the upper belt or the lower belt and the heat exchanger pipe outside the line contacts and / or point contacts. The heat exchanger tubes are located between two different spacers.

Furthermore counts by the FR 2 128 197 a heat exchanger assembly of the prior art, in which upper flange and lower flange of spacer elements are integral parts of a spacer. Upper and lower belt are arranged offset from each other in the longitudinal direction. The heat exchanger tubes are arranged between the upper chords and the lower chords of different spacers. FR 2 128 197 shows a heat exchanger according to the preamble of claim 1.

Also the FR 2 355 191 discloses spacers for heat exchanger tubes in which the upper and lower chords of the spacers are offset longitudinally from one another and are integral parts of the spacer. The tubes are located between different spacers, which are arranged so that free spaces remain between the spacers for receiving the heat exchanger tubes.

It counts through the DE 10 2005 012 868 B3 a holding device for heat exchanger elements of the prior art, in which a surface contact with the heat exchanger tubes is desired. Line contact should be avoided to minimize local loads.

Proceeding from this, the present invention seeks to show a device for distancing heat exchanger tubes, in which on the one hand ensures that between the adjacent heat exchanger tubes large free spaces exist, so they can not clog, and on the other hand, but also ensures that corrosion is avoided in the area of spacers.

This object is achieved with a device having the features of patent claim 1.

Advantageous developments of this device are the subject of the dependent claims.

In the apparatus according to the invention, the heat exchanger tubes are provided encompassing, strip-shaped spacers. The spacers each have a top chord and a bottom chord, wherein the terms "upper" and "lower" are not to be understood spatially, but to express that in each case a belt runs on one side of the heat exchanger tube. Consequently, the heat exchanger tubes are arranged between the upper flange and the lower flange. The upper flange and the lower flange are connected to each other outside their areas surrounding the heat exchanger tubes.

It is essential that the heat exchanger tubes are in a direction in the direction of the tube axis of the heat exchanger tubes extending line contact and / or point contact with the upper flange and the lower flange. The spacers thus do not nestle against the heat exchanger tubes but touch them only selectively when viewed in the circumferential direction, so that free spaces are specifically provided between the upper flange or lower flange and the heat exchanger tube outside the line contacts and / or point contacts. The free spaces are dimensioned so large that any particles of the heat exchange medium flowing around the heat exchanger tubes can pass through the free spaces as unhindered as possible, so that no encrustations and deposits can form, which promote corrosion. In this case, it is assumed that the contour of the upper flange or lower flange deviates from the contour of the heat exchanger tubes. In the case of cross-sectionally round or elliptical heat exchanger tubes, line and / or point contacts can be realized in that the top flange and / or the bottom flange have a polygonal bulge for receiving the heat exchanger tube. Polygonal bulges can be produced particularly easily by multiple folding. Theoretically, it is within the scope of the invention also possible to provide rounded bulges provided that it is ensured that the individual curves of the bulges do not coincide with the cross-sectional shape of the heat exchanger tube.

In polygonal bulges line contacts between the heat exchanger tube and the top flange or bottom flange arise automatically. Of course, it is possible in place of the line touch also targeted point contact caused by individual surveys in the region of the spacers. It is also crucial that a sufficient space between the top flange and the lower flange and the heat exchanger tube is present.

The greater the number of line contacts and / or point contacts of a heat exchanger tube with a spacer, the more frequently these two components approach each other. Consequently, this results in a reduction of the free spaces between the heat exchanger tube and the spacer. Therefore, the number of line touches and / or point touches over the peripheral area of a heat exchanger tube should be less than 6.

A secure position orientation in a radial plane is already possible with three line or point contacts. This would correspond to incorporation of the heat exchanger tube into a triangular bulge. Such a triangular bulge can be provided only on one of the straps, while the other belt runs virtually straight.

Of course, it is also possible to provide bulges in the upper flange and at the same time in the lower flange, with the bulges opposite each other. Between the upper flange and the lower flange then results in a square or diamond-shaped breakthrough.

Of course, it is possible to provide other than triangular bulges. Preferably, however, each polygonal bulge should have an even number of side surfaces or have an odd number of corners.

The spacer is integrally formed. This means that upper flange and lower flange do not have to be additionally connected in a form-fitting or cohesive manner, but are manufactured by forming a single semifinished product. In this case, upper flange and lower flange are offset from one another in the direction of the tube axis. This means that the spacer is wider overall than the individual straps.

Preferably, the straps have the same width and are issued from a flat workpiece in opposite directions. Of course, it is also possible in one direction of the strip-shaped spacer expose a belt, for example, the upper belt and to point in the other direction two lower straps, in this case, the number of upper straps of a spacer deviates from the number of lower straps of the spacer.

It is considered advantageous if a measured in the longitudinal direction of the heat exchanger tube width of a top chord or a lower chord to the outer diameter of the heat exchanger tube in the ratio 1: 1 to 1: 3.

The spacers are preferably made of sheet metal, since this material has a sufficient flexural rigidity and with appropriate choice of material sufficient corrosion resistance. However, it is also conceivable that the spacers are made of a suitable plastic.

• Figur 1 eine schematische Darstellung eines Wärmetauschers;
• Figuren 2a) - 2d) eine Vorrichtung zur Distanzierung von Wärmetauscherrohren;
• Figuren 3a) - 3d) eine Vorrichtung zur Distanzierung von Wärmetauscherrohren;
• Figur 4 eine vergrößerte Darstellung der Vorrichtung gemäß der Figur 3b;
• Figuren 5a) - 5d) eine Vorrichtung zur Distanzierung von Wärmetauscherrohren;
• Figur 6 eine vergrößerte Darstellung der Figur 5b;
• Figuren 7a - 7d eine erfindungsgemäße Ausführungsform einer Vorrichtung zur Distanzierung von Wärmetauscherrohren und Figuren
• Figuren 8a - 8d eine erfindungsgemäße Ausführungsform einer Vorrichtung zur Distanzierung von Wärmetauscherrohren.

The invention will be explained in more detail with reference to the drawings. Show it:

• FIG. 1 a schematic representation of a heat exchanger;
• Figures 2a) - 2d ) a device for distancing heat exchanger tubes;
• FIGS. 3a) - 3d ) a device for distancing heat exchanger tubes;
• FIG. 4 an enlarged view of the device according to the FIG. 3b ;
• Figures 5a) - 5d ) a device for distancing heat exchanger tubes;
• FIG. 6 an enlarged view of FIG. 5b ;
• FIGS. 7a-7d an inventive embodiment of a device for distancing heat exchanger tubes and figures
• FIGS. 8a-8d an inventive embodiment of a device for distancing heat exchanger tubes.

FIG. 1 shows a heat exchanger. Gas is introduced in the direction of the arrow P in the heat exchanger and flows around a bundle of heat exchanger tubes 1, through which a medium flows. The arrows P1 illustrate the flow direction.

The heat exchanger tubes 1 are configured U-shaped and parallel to each other. For orientation, devices for distancing the heat exchanger tubes 1 are provided. These are strip-shaped spacers 2, which are explained in different embodiments with reference to the following figures. The FIGS. 7 and 8th show the embodiments of the invention.

In the FIGS. 2a-2d the strip-shaped spacer has a top flange 3 and a bottom flange 4. These are metal strips that correspond in width to the diameter of the heat exchanger tubes 1. In FIG. 2b it can be seen that the upper belt 3 is straight, while the lower belt 4 is configured to a certain extent zigzag-shaped. As a result, the straps 3, 4 in the region of the circular heat exchanger tube 1 are not flat on this but are in line contact with the heat exchanger tube 1. The heat exchanger tube 1 is thus fixed in position over three points. On the one hand, the heat exchanger tube touches the upper flange 3. Two further line contacts are present on the lower flange 4. Due to the strip-shaped design of the spacers 2, the line contacts extend in the longitudinal direction of the heat exchanger tubes. 1

It is essential in the apparatus that free spaces 5 are present between the heat exchanger tube 1 and the spacer 2 surrounding the heat exchanger tube 1. From the representation of FIGS. 2b) and 2d ) it becomes clear that the free spaces 5 are dimensioned relatively large, so that the risk of deposits in this area is very low.

From the in the presentation of the FIGS. 2c) and 2d ) is also clear that the lower flange 4 can contact the upper flange 3 of an adjacent spacer 2, so that the individual rows of the heat exchanger tubes 1 are spaced by the spacers 2.

The FIG. 3 is different from the one of FIG. 2 in that the spacer 2a shown there has a slightly different bottom flange 4a. The lower flange 4a is also configured polygonal in a basic configuration, but the individual bulges 6a are not triangular but pentagonal. This is clear from the enlarged illustration in FIG FIG. 4 to recognize. Due to the pentagonal configuration of the bulges 6, the heat exchanger tube 1 is located on the upper flange 3a and the lower flange 4a via five line contacts. The top flange 3a extends, as in the embodiment of FIG. 2a ) just. The bulges 6a are provided exclusively in the lower flange 4a.

Another difference compared FIG. 2 is that the upper flange 3a has been positively connected to the lower flange 4a. In this embodiment, the upper flange 3a is clinched with the lower flange 4a. The corresponding connection point 7 of Verclinchung are issued in the direction of the lower belt 4a. Such connection points 7 can in principle be arranged between two adjacent heat exchanger tubes 1, that is to say where upper flange 3a and lower flange 4a approach and touch. In principle, however, it is also possible that the connection points 7 are arranged on the edge side of the heat exchanger tubes 1 in laterally projecting flanges.

Alternatively to a positive connection, as in the Figures 3 and 4 is shown, the straps of the spacers 2, 2a may also be materially connected to each other, such as by welding or soldering.

The Figures 5 and 6 shows a spacer 2b, in which triangular-shaped bulges 6b are provided both in the upper flange 3b and in the lower flange 4b. The bulges 6b in upper flange 3b and lower flange 4b face each other, so that a quadrangular space is enclosed, in which the Heat exchanger tubes 1 run. There are four lines of contact with the heat exchanger tube 1. Accordingly, there are four free spaces 5. It can be seen that the upper flange 3b and the lower flange 4b are in turn positively connected by clinching with each other. In this arrangement, with three heat exchanger tubes 1, two connection points 7 are provided, wherein in turn a connection point 7 is arranged in the peripheral flange region of the spacer 2b and a connection point 7 between two heat exchanger tubes. 1

The embodiment of the invention FIG. 7 shows a spacer 2c which is made in one piece from a single sheet metal component. Unlike the Figures 5 and 6 Are upper flange 3c and lower flange 4c not in a radial plane of the heat exchanger tubes 1 opposite, but are offset in the longitudinal direction of the heat exchanger tubes 1 to each other, as shown in the FIGS. 7a) and 7c ) is recognizable. The spacer 2c has protrusions 6c facing in opposite directions. In the sectional view of FIGS. 7b) and 7d ), this configuration is almost identical to that of the Figures 5 and 6 with the difference that the upper flange 3c and the lower flange 4c need not be additionally connected to each other. The connection is predetermined by the integral nature of the spacer 2c.

In the embodiment of the invention the FIG. 7 In each case a top flange 3c and a bottom flange 4c is provided. In principle, however, it is conceivable to provide a plurality of upper or lower chords even when producing a spacer from a single metal sheet. A possible example is in FIG. 8 shown. It can be seen that the width of the spacer 2d measured in the longitudinal direction of the heat exchanger tube 1 has once again been increased, this spacer 2d, in contrast to the embodiment of FIGS FIG. 7 a lower flange 4d and two upper straps 3d, 3e. Incidentally, the cross-sectional configuration of the protrusions 6d corresponds to that of FIG FIG. 7 ,

Reference numerals:

1

heat exchanger tube

2

spacer

2a

spacer

2 B

spacer

2c

spacer

2d

spacer

3

upper chord

3a

upper chord

3b

upper chord

3c

upper chord

3d

upper chord

3e

upper chord

4

lower chord

4a

lower chord

4b

lower chord

4c

lower chord

4d

lower chord

5

Free rooms

6a

bulge

6b

bulge

6c

bulge

6d

bulge

7

connection points

P1

arrow

P2

arrow

Claims (8)

1. Heat exchanger having heat exchanger tubes and a device for spacing the heat exchanger tubes (1), comprising strip-shaped spacers (2, 2a - d) which encompass a row of heat exchanger tubes (1) extending parallel to one another, the spacers (2, 2a - d) having projections which point in opposing directions, the spacers (2, 2a - d) having an upper flange (3, 3a - e) and a lower flange (4, 4a - d) between which the heat exchanger tubes (1) are arranged, the heat exchanger tubes (1) being in line contact extending in the direction of the tube axes of the heat exchanger tubes (1) and/or point contact with the upper flange (3, 3a - e) and the lower flange (4, 4a - d), there being free spaces (5) between the upper flange (3, 3a - e) or lower flange (4, 4a - d) and the heat exchanger tube (1) outside the line contact and/or point contact, the upper flange (3c - e) and lower flange (4c, 4d) extending offset from one another in the longitudinal direction and being integral components of a spacer (2c, 2d), characterised in that the heat exchanger tubes (1) are arranged between the upper flanges (3c, 3d) and lower flanges (4c, 4d) of said spacer (2c, 2d).
2. Heat exchanger according to claim 1, characterised in that the number of line contacts and/or point contacts between a heat exchanger tube (1) and a spacer (2, 2a - d) is lower than six.
3. Heat exchanger according to either claim 1 or claim 2, characterised in that either the upper flange (3, 3a - e) or the lower flange (4, 4a - d) has a polygonal projection for receiving a heat exchanger tube (1).
4. Heat exchanger according to claim 3, characterised in that each polygonal projection (6a - d) has an even number of lateral faces.
5. Heat exchanger according to claim 1, characterised in that the number of upper flanges (3c, 3d) of a spacer (2c, 2d) differs from the number of lower flanges (4c, 4d) of the spacer (2c, 2d).
6. Heat exchanger according to any one of claims 1 to 5, characterised in that the width of an upper flange (3, 3a - e) or a lower flange (4, 4a - d), measured in the longitudinal direction of a heat exchanger tube (1), is at a ratio of from 1:1 to 1:3 to the outer diameter of the heat exchanger tube (1).
7. Heat exchanger according to any one of claims 1 to 6, characterised in that the spacers (2, 2a - d) are produced from sheet metal.
8. Heat exchanger according to any one of claims 1 to 6, characterised in that the spacers (2, 2a - 2d) are produced from plastics material.

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