DE202017103235U1 - heat exchangers - Google Patents

Abstract

Heat exchanger (1), in particular charge air cooler of an internal combustion engine, comprising - a plurality of channels (2) for passing a cooling medium, - a plurality of flat tubes (3) connected to at least one collecting box (4) for passing a medium to be cooled between each of the channels (2), - At least one the collecting box (4) closing the tube bottom (5) with Rohrdurchzügen (6), in which end pipe ends (7) of the tubes (3) are fluid-tightly received, - wherein each of the tube passages (6) has a respective flat tube (3) in which at least one of the collars (8) has a plurality of tongues (10) extending away from the tube bottom (5) in the region of the broad sides (12) of the flat tubes (5), extending from a circumferential collar neck (9). characterized by cutouts (15) are separated from each other, characterized in that- the edges (14) of the tongues (10) have radii (R).

Description

The present invention relates to a heat exchanger, in particular a charge air cooler of an internal combustion engine, according to the preamble of claim 1.

A generic heat exchanger, for example, known from the DE 10 2012 219 268 A1 or the GB 169855 A consist essentially of a stack of superimposed channels, in particular corrugated fins, and flat tubes and usually two headers with respective tube sheets with Rohrdurchzügen, are fluid-tightly received by the frontal pipe ends of the tubes.

The tubes are thereby flowed through by a first fluid, for example, charge air, while the channels are traversed by a second fluid, such as cooling air. The openings referred to as pipe passages in the tubesheets are formed with a collar which usually has a collar extending from the interior of the respective collecting tank and has a respective flat tube. The flat tubes are usually connected to the tubesheets by soldering.

In practical operation, these heat exchangers are exposed to changing internal pressure loads and temperature changes. Both the internal pressure loads and the temperature changes can lead to high voltages in the area of the tube-tube-bottom connection and thus considerably influence the service life of the heat exchanger.

To reduce these tensions, it is out of the GB 169855A known to form the collar with juxtaposed triangular tongues to ensure a more uniform transition of a thin material cross-section of the flat tube on the common cross section of flat tube and collar. This ensures that the connection between the flat tube and collar compliant and the voltages occurring are reduced.

Disadvantages of this solution are on the one hand the stress concentrations at the tips of these triangular tongues and a notch effect in a notch between respective adjacent tongues.

Object of the present invention is to further develop a heat exchanger of the generic type such that a further reduction of the voltages occurring in practical operation is ensured, thus further increasing the life of the heat exchanger with changing internal pressure and temperature loads.

This object is achieved by a heat exchanger having the features of claim 1.

The heat exchanger according to the invention has a plurality of channels for the passage of a cooling medium and a plurality of flat tubes connected to at least one collecting box for the passage of a medium to be cooled between each of the channels.

The collecting box is closed on one side by a tubesheet, which has pipe passages which are fluid-tightly received in frontal pipe ends of the tubes.

Each of the tube passages has a raised collar comprising a respective flat tube.

At least one of the collars has a plurality of tongues extending from the tube bottom in the region of the broad sides of the flat tubes, which are separated from one another by cutouts.

The edges of the tongues have radii.

By the edges formed at the edges tong concentrations are avoided, which increases the life of the heat exchanger.

Advantageous embodiments of the invention are the subject of the dependent claims.

According to an advantageous embodiment variant, at least the transition region between one of the tongues and an adjacent tongue or a region of the collar not divided by cutouts is rounded.

According to a further advantageous embodiment, at least the free ends of the tongues are rounded.

The avoidance of peaks on the collar ensures a significant reduction of stresses in the tube-tube bottom connection.

According to a further advantageous embodiment, have corner areas of the collar, which abut on narrow sides with broad sides connecting areas of the flat tubes, no cutout, so that the collar is maintained in full height in these corners.

According to a further advantageous embodiment variant, the broad sides of the flat tubes comprising regions of the collar tongues and cutouts in a cutout area near the narrow sides of the flat tubes.

In the central region of the broad sides of the tubes, the collars can be retained here in full length, since the greatest stresses occur in the narrow sides of the tubes and in the adjacent regions of the broad side of the flat tubes.

The length of the tongues in the longitudinal direction of the flat tubes is preferably between 0.6 and 0.9 times the collar length. The collar length is measured in the longitudinal direction of the flat tubes, starting from the plane of the tube plate.

According to a further advantageous embodiment, the minimum radius of the edges of the tongues is between 0.3 and 0.6 times the length of the tongues.

With such minimal radii, a significant reduction in stress is achieved.

According to a further advantageous embodiment, the pitch of the cutouts in the collar of a flat tube is variably formed. The pitch is preferably formed in the region of the broad sides of the flat tubes rising from an area near the narrow sides of the flat tubes to the middle of the broad side.

This takes into account that greater stresses occur mainly in the region of the narrow side of the flat tubes and in adjoining areas of the broad sides of the tubes.

According to a further advantageous embodiment of the tube sheet is formed curved in a plane perpendicular to the longitudinal direction of the flat tubes.

Particularly preferably, the tube sheet is formed centrally arched towards the collection box out.

Also conceivable are wave-shaped tube sheets.

Such curved tube sheets are particularly well suited for internal pressure loads. The advantage of an inwardly curved tube bottom is the fact that, with the outer dimensions of the heat exchanger remaining the same, the network of tubes and channels can be made larger and thus additional heat transfer surface can be obtained.

• 1 eine perspektivische Ansicht eines Wärmeaustauschers mit Sammelkästen, Rohren und Kanälen,
• 2 eine perspektivische Ansicht einer Ausführungsvariante eines Rohrbodens mit Rohrdurchzügen und an diesen angeformten Kragen,
• 3 eine perspektivische Ansicht des Rohrboden gemäß 2 aus einer anderen Perspektive,
• 4 eine Seitenansicht auf einen solchen Rohrdurchzug mit daran angeformtem Kragen,
• 5-7 den 2 -4 entsprechende Darstellungen eines gewölbten Rohrbodens,
• 8 eine schematische perspektivische Ansicht eines Rohrdurchzugs mit eingestecktem Flachrohr,
• 9 eine schematische Darstellung eines Ausschnitts des Kragens zur Darstellung von Breite, Länge und Radius des Ausschnitts und
• 10 eine schematische Darstellung eines Kragenabschnitts.

Hereinafter, preferred embodiments will be explained in more detail with reference to the accompanying drawings. Show it:

• 1 a perspective view of a heat exchanger with headers, pipes and channels,
• 2 a perspective view of an embodiment of a tube sheet with pipe passages and molded on this collar,
• 3 a perspective view of the tube sheet according to 2 from a different perspective,
• 4 a side view of such a pipe passage with molded collar,
• 5-7 the 2 - 4 corresponding representations of a curved tube bottom,
• 8th a schematic perspective view of a pipe penetration with inserted flat tube,
• 9 a schematic representation of a section of the collar to illustrate the width, length and radius of the section and
• 10 a schematic representation of a collar portion.

In the following description of the figures, terms such as above, below, left, right, front, back, etc. refer exclusively to the exemplary representation and position of the heat exchanger, the channel, the flat tube, the collecting box, the collar, the cutout selected in the respective figures , the tongue and the like. These terms are not meant to be limiting, that is to say, by different working positions or the mirror-symmetrical design or the like, these references may change.

In 1 is with the reference numeral 1 overall designates a variant of a heat exchanger according to the invention. The heat exchanger 1 has several channels 2 for the passage of a cooling medium as well as several pipes 3 for the passage of a medium to be cooled. The channels 2 and the pipes 3 are arranged alternately to a stack.

In the channels 2 are preferably fins 18 used to increase an interacting with the cooling medium cooling surface.

In the flat tubes 3 are preferably also slats 17 used. Also conceivable are flat tubes 3 without such slats 17 ,

Through the flat tubes 3 Preferably, the medium to be cooled flows in a flow direction x.

The pipe ends 7 the flat tubes 3 lead into respective collection boxes 4 of the heat exchanger 1 , Each of the collection boxes 4 has a tube bottom 5 on, with pipe ducts 6 is provided, as it is in the 2 . 3 . 5 and 6 is shown. In these pipe wraps 6 are the front pipe ends 7 the flat tubes 3 recorded fluid-tight, preferably soldered or glued.

The collection boxes 4 have respective inlet and outlet openings in or out of which the medium to be cooled on or flows, wherein the medium to be cooled by the one of the collecting tanks 4 through the flat tubes 3 through to the other collection box 4 flows.

As in the 2 to 8th shown points each of the pipe passages 6 a respective flat tube 3 comprehensive collar 8th on.

At least one of the collars 8th has several of a circumferential collar neck 9 down from the tubesheet 5 away tongues 10 in the range of broadsides 12 the flat tubes 5 on, by cutouts 15 are separated from each other.

As in the 3 . 4 and 6 and 7 shown, have the edges 14 the tongues 10 radii R on, which can be kept very small in the pipe tube plate connection occurring during operation voltages.

The tube sheets 5 can do it like in the 2 to 4 shown, just shaped.

According to an alternative embodiment, as in the 5 to 7 is shown, the tube sheets 5 in a plane perpendicular to the longitudinal direction x of the flat tubes 3 arched trained.

Particularly preferred are the tube sheets 5 while in the middle of the collection box 4 arched or indented formed.

As in the 3 . 4 . 6 and 7 shown are the tongues 10 shaped so that at least the transition area between one of the tongues 10 and a neighboring tongue 10 rounded is formed.

Also between a tongue 10 and one not by cutouts 15 divided areas of the collar 8th are rounded.

The tongues 10 are doing by punching or cutting in the longitudinal direction of the flat tubes 3 Consistently long collar made, with the removed cutouts 15 are also rounded.

In particular, at least the free ends 16 the tongues 10 rounded, as exemplified in 4 is shown.

As in the 3 and 6 can be seen, are corner areas 19 the collar 8th on the narrow sides 13 with broadsides 12 connecting areas of the flat tubes 3 abut, obtained in full length, to provide a stable support between tubesheet 5 and flat tubes 3 to ensure.

Between the corners 19 the collar 8th can, as in the 3 and 6 shown, a section 15 in the area of the narrow sides 13 the flat tubes 3 be provided.

As in the 3 . 4 . 6 and 7 shown are the tongues 10 or cutouts 15 not evenly distributed along the collar 8th educated.

Rather, the preferred are the broadsides 12 the flat tubes 3 extensive areas of the collar 8th designed such that only in a cutout area A, near the narrow sides 13 the flat tubes 3 , the collar 8th with tongues 10 and cutouts 15 is trained.

The free ends of the tongues 10 as well as not by cutouts 15 broken areas of the collar 8th preferably have to the outer sides of the flat tubes 3 inclined ends 11 on to an improved attachment of the collar 8th on the flat tubes 3 to make sure.

While at the in the 4 and 7 embodiment shown the cutouts 15 are arranged at equal distances from each other, it is also conceivable, the division T _{A of} the cutouts 15 in the collar 8th a flat tube 3 variable form.

Thus, the division T _A in the range of the broadside 12 the flat tubes 3 especially from an area near the narrow sides 13 the flat tubes 3 to the middle of the broadside 12 be formed rising.

As in the 8th . 9 and 10 shown is the width B _AB each of the clipping areas FROM preferably between 0.2 and 0.3 times the width B _R the flat tubes 3 ,

The length L _A the cutouts 15 corresponding length L _Z the tongues 10 longitudinal X the flat tubes 3 is preferably between 0.6 and 0.9 times the collar length L _K ,

The minimum radius _Min the edges 14 the tongues 10 is preferably between 0.3 and 0.6 times the length L _A the cutouts 15 ,

Preferably, in the region of the narrow sides 13 the flat tubes 3 the width B _A the cutouts 15 between 0.3 and 0.5 times the height H _R the flat tubes 3 ,

In the area of broadsides 12 the flat tubes 3 is the width B _A the cutouts 15 preferably between 0.6 and 1.5 times the collar length L _K ,

The cutouts 15 can do this, such as in the 9 or 7 be shown so close together that their expiring radii merge seamlessly into each other.

However, it is also conceivable divisions of the cutouts, in which adjacent cutouts are so far apart that between them a collar portion is formed with a straight collar edge.

Due to the fact that the load of more outer flat tubes 3 opposite those of inner flat tubes 3 may be different, it is also conceivable only a few of the pipe passages 6 , in particular the pipe passages 6 for holding the flat tubes further out in the package 3 with cutouts 15 in the collar 8th to provide.

LIST OF REFERENCE NUMBERS

1

heat exchangers

2

channel

3

flat tube

4

collection box

5

tube sheet

6

pipe threading

7

pipe end

8th

collar

9

collar

10

tongue

11

The End

12

broadside

13

narrow side

14

edge

15

neckline

16

The End

17

lamella

18

lamella

19

corner

X

Longitudinal direction of the flat tubes

FROM

Trimming area

B _AB

Width of the clipping area

B _A

Width of the cutouts

L _A

Length of the cutouts

L _Z

tongue length

B _R

tube width

H _R

tube height

L _K

collar length

R

radius

_Min

minimal radius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012219268 A1 [0002]
• GB 169855 A [0002, 0005]

Claims (15)

Heat exchanger (1), in particular charge air cooler of an internal combustion engine, comprising - a plurality of channels (2) for passing a cooling medium, - a plurality of flat tubes (3) connected to at least one collecting box (4) for passing a medium to be cooled between each of the channels (2), - At least one the collecting box (4) closing the tube bottom (5) with Rohrdurchzügen (6) in which end pipe ends (7) of the tubes (3) are fluid-tightly received, - wherein each of the tube passages (6) has a respective flat tube (3) in which at least one of the collars (8) has a plurality of tongues (10) extending away from the tube bottom (5) from a peripheral collar neck (9) in the area of the broad sides (12) of the flat tubes (5). characterized by cutouts (15) are separated from each other, characterized in that - the edges (14) of the tongues (10) have radii (R). Heat exchanger (1) after Claim 1 , characterized in that at least the transition region between one of the tongues (10) and an adjacent tongue (10) or a not by cutouts (15) divided area of the collar (8) is rounded. Heat exchanger (1) after Claim 1 or 2 , characterized in that at least the free ends (16) of the tongues (10) are rounded. Heat exchanger (1) according to any one of the preceding claims, characterized in that corner regions of the collars (8), which rest on narrow sides (13) with broad sides (12) connecting regions of the flat tubes (3) have no cutout. Heat exchanger (1) according to one of the preceding claims, characterized in that the wide sides (12) of the flat tubes (3) comprising the region of the collar (8) tongues (10) and cutouts (15) in a cutout (AB) near the narrow sides (13) of the flat tubes (3). Heat exchanger (1) after Claim 5 , characterized in that the width (B _AB ) of each of the cutout areas (AB) is between 0.2 and 0.3 times the width of the flat tubes (3). Heat exchanger (1) according to one of the preceding claims, characterized in that the length (L _Z ) of the tongues (10) in the longitudinal direction of the flat tubes (3) is between 0.6 and 0.9 times the collar length (L _K ) , Heat exchanger (1) according to one of the preceding claims, characterized in that the minimum radius (R _min ) of the edges (14) of the tongues (10) is between 0.3 and 0.6 times the length (L _Z ) of the tongues (10). Heat exchanger (1) according to one of the preceding claims, characterized in that in the region of the narrow sides (13) of the flat tubes (3), the width (B _A ) of the cutouts (15) between 0.3 and 0.5 times the height (H _R ) of the flat tubes amounts. Heat exchanger (1) according to one of the preceding claims, characterized in that in the region of the broad sides (12) of the flat tubes (3), the width (B _A ) of the cutouts (15) between 0.6 and 1.5 times the collar length (L _K ) is. Heat exchanger (1) according to one of the preceding claims, characterized in that the pitch (T _A ) of the cutouts (15) in the collar (8) of a flat tube (3) is variable. Heat exchanger (1) after Claim 11 , characterized in that the pitch (T _A ) in the region of the broad sides (12) of the flat tubes (3) from an area near the narrow sides (13) of the flat tubes (3) to the middle of the broad side (12) is formed rising. Heat exchanger (1) according to one of the preceding claims, characterized in that the tube plate (5) is planar in a plane perpendicular to the longitudinal direction (x) of the flat tubes (3). Heat exchanger (1) according to any one of the preceding claims, characterized in that the tube plate (5) is curved in a plane perpendicular to the longitudinal direction (x) of the flat tubes (3). Heat exchanger (1) after Claim 14 , characterized in that the tube plate (5) is formed centrally curved towards the collecting box (4).

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