DE102015014047A1 - Tube sheet and heat exchanger - Google Patents

Abstract

The invention relates to a tube plate (1) for a heat exchanger, having at least one row of first openings (10) for receiving tube ends of the tubes (2) of the heat exchanger, and at least two second openings (20), one at each of two opposite ends the tube bottom (1) arranged to receive and fix one end of a first stability member (3a), such as a side part of the heat exchanger. In order to make the tube sheet more stable and to inexpensively avoid fractures caused by temperature change, it is provided according to the invention that at least one third opening (30) is present within the row of first openings (10), in each case one end of a second stability member ( 3b) is attached. Alternatively, within the row of first openings (10) there may also be an opening-free section (4) which extends in the longitudinal direction of the tube bottom (1) at least over a plurality of tube spacings. Furthermore, a heat exchanger equipped with such tube sheets (1) with two collecting boxes (6) is also proposed. In a collecting box 6 there is a partition wall 7 which divides the collecting box 6 into an inlet-side part 6a and an outlet-side part 6b. Close to the partition wall 7, the second stability elements 3b are arranged.

Description

The invention relates to a tube plate for a heat exchanger and a heat exchanger having such tube plates and with further specified in the respective preambles of the claims characteristics.

Out DE 2 628 331 A is a water tank for a cross-flow cooler known. The cross-flow cooler has an inlet-water tank - following collection box - which is disposed at one end of a cooling water tube bundle (pipes and ribs) and which has approximately in the middle of a vertically arranged to the longitudinal partition wall, the said collection box in an inlet-side part and an outlet side Part divided. Therefore, at another end of the tube bundle, another collection box, which thus functions as a deflection box to the cooling water, from the inlet side part via an inlet side tube bundle part incoming divert, in an exit-side tube bundle part, from there finally to land in the outlet side header section and to leave the cooler again. On the way described the cooling water cooling takes place by means of flowing through the ribs cooling air.

The features of the abovementioned generic terms do not all come from the cited and described prior art. The cooler described has, for example, no stability organs, that is no side parts, and therefore also no second openings in the tubesheets. However, the features of the preambles have long been common practice in heat exchangers.

In heat exchangers of this well-known type has recently been observed that material fractures have manifested that can lead to total failure of the heat exchanger.

The object of the invention is to at least mitigate or even completely eliminate the problems mentioned in the simplest possible and cost-saving manner.

This object is achieved with a tubesheet for a heat exchanger having the features of claim 1 or claim 3 and also with a heat exchanger with such tube sheets according to claim 5.

According to an aspect of the invention, with respect to the tube bottom, a heat exchanger having at least one row of first openings for receiving tube ends of the heat exchanger and at least two second openings, one at both opposite ends of the tubesheet, for receiving and securing one end of a first stability member, such as a side part of the heat exchanger, provided that within the series of first openings at least a third opening is arranged, in each of which one end of a second stability member is attached.

A second or alternative solution with regard to the tube bottom provides, according to the invention, for arranging within the row of first openings an opening-less section, that is to say a section without openings, which extends in the longitudinal direction of the tube bottom at least over a plurality of tube spacings. One-sided or two-sided of the section 4 the second stability organs can be arranged.

It may not be preferred, but quite possible, on the same heat exchanger both the proposal according to claim 1 and - at another point of the heat exchanger - implement the proposal according to claim 3.

The third opening consists in a particularly preferred application of the heat exchanger of two relatively close to each other arranged third openings, wherein a further or a second (second) stability member is present, the end of which is fixed in the second of the third openings. Between the two second stability organs, a corrugated fin is placed.

The heat exchanger according to the invention accordingly comprises at least one row of tubes, for example flat tubes, and interposed ribs, usually corrugated fins, as well as two of the tube sheets described, each with a series of first openings for receiving the tube ends and also collecting boxes which are connected to the tubesheets. Furthermore, a respective first stability element, for example a so-called side part, is provided, the opposite ends of which are fastened in the second openings of the tubesheets. The seated with their ends in the second openings of the tubesheets side parts are known to be on the left and right edges of a consisting of the flat tubes and the ribs cooling network, and they extend from one tube sheet to the opposite second tube sheet.

In contrast to the prior art, the tube sheets also have at least one, but often two or more third openings for receiving one end of one or two or more second stability organs.

According to one embodiment, the first and the second stability organs are identically designed to cause the least possible costs. This means that the first and second openings are identical. One could even make the first, second and third openings identical in shape. It is usually the case that the first openings are all identical, since the tubes are also identical. As mentioned, the second and third openings are also identical but sometimes slightly smaller than the first openings, since the ends of the stability members may have a recess-like shoulder with only the tapered end of the stability member seated in the second and third openings, respectively ,

The ends can be subjected to a forming step, seated in the second or in the third openings, after which they are non-positively fixed in the same. After carrying out the mentioned forming step, the stability organs brace the two tube plates together and thus give the heat exchanger the promised stability.

A particularly preferred heat exchanger is characterized in that in one of the collecting tanks a substantially transverse to its longitudinal extent arranged partition wall is present, which stands on the tube sheet, and divides the collecting box into an inlet-side part and an outlet-side part.

In a particularly preferred manner, the collecting box has been produced as an injection-molded part made of plastic, wherein the mentioned dividing wall-as is known per se-is formed integrally with the collecting box wall. This preferred heat exchanger has at its opposite pipe ends a second header, which works as a deflection box. Accordingly, this preferred heat exchanger is flowed through in a U-shape.

As already mentioned in the introduction, the inventors have observed precisely in this type of heat exchanger, the material fractures and indeed, usually in the vicinity of the aforementioned partition. The existing near the partition metallic connections between the pipe ends and the first openings are often broken in the prior art.

The inventors are known because of their experience that material fractures occur even with heat exchangers without a partition and therefore rectilinear or otherwise different flow, the causes can often not be accurately identified. It can be both extreme thermal cycling and high mechanical loads. Often with both and additionally with other burdens. They therefore propose to use the third openings in the tubesheets and the second stability organs seated therein also in the vicinity of those locations of such heat exchangers without dividing wall, at which the material fractures have often manifested themselves.

If at least two third openings are provided in the tubesheet, it is advantageous to arrange one on the left and another on the right of the dividing wall, in which a further second stability element is present.

In most cases - but by no means always - the partition wall and the second stability elements are located approximately in the middle of the row of flat tubes or in the middle of the heat exchanger.

The heat exchanger is preferably a cooling liquid cooler for a motor vehicle, wherein the flat tubes are flowed through by the cooling liquid and the corrugated ribs by cooling air. Other heat exchangers such as oil cooler or intercooler are not excluded.

The first and second stability members are configured to allow for thermal expansion / contraction in their longitudinal direction, such as a partial severance cut or bead or other longitudinally compliant design. Particularly preferred in this regard is one (or more) predetermined breaking point (s), which usually break already after the first startup of the heat exchanger, without impairing the function of the heat exchanger and the stability elements. As is well known, all metallic constituents, such as tube sheets and cooling network, have previously been connected in a metallic manner (for example in a soldering oven) so that the (intended) fractures at the predetermined breaking points do not adversely affect the heat exchanger in its structure. The intended improvement in stability in the area of the tube sheets - where the mentioned fractures have occurred earlier - is not affected by the fractures of the predetermined breaking points.

The inventors have also found that the positioning of the predetermined breaking points has a significant influence on their effectiveness. For example, the provision of a predetermined breaking point at a distance of about 10-70 mm from a tube sheet has shown a much higher potential for improvement than an identical predetermined breaking point, which was located about 170 mm from the tube sheet.

The invention will be described below in some embodiments with reference to the accompanying drawings. The Description includes other features and advantages of the invention, which may later turn out to be salient features that are essential.

Brief Description

The 1 shows a perspective view of a preferred heat exchanger.

The 2 shows a heat exchanger that too 1 could belong but without collecting boxes.

The 3 shows a part of the 1 ,

The 4 shows a part of the 2 ,

The 5 shows a part of a tube plate according to a modified embodiment.

The 6a - 6c show different stability organs.

The 7 shows a tube sheet according to the preferred embodiment.

The 8th - 10 show an alternative embodiment.

The heat exchanger comprises according to the representations in the 1 and 2 at least a row of pipes 2 , in the cases shown, a series of flat tubes 2 , and ribs between them 5 , An unillustrated heat exchanger has a plurality of tube rows arranged one behind the other in the direction of air flow. Ribs 5 are in the cases shown as corrugated ribs 5 educated.

Furthermore, the heat exchanger has two oppositely arranged tube sheets 1a . 1b each with a series of first openings 10 for receiving the tube ends of the flat tubes 2 and also collection boxes 6 that with the tube sheets 1a . 1b are connected.

In addition, each is a first stability organ 3a as a side part 3a provided, the opposite ends in second openings 20 the tube sheets 1a . 1b are attached. The with their ends in the second openings 20 the tube sheets 1a . 1b sitting side parts 3a are located on the left and right edge of one of the flat tubes 2 and the corrugated ribs 5 existing cooling network, and they extend from the one tubesheet 1a to the opposite second tube sheet 1b ,

The tube sheets 1a . 1b moreover, as shown, have two third openings 30 for receiving one end of two second stability organs 3b , In cases not shown one has more than two third openings 30 with correspondingly several stability organs 3b intended.

Like from the 1 shows, is in the upper collection box in the figure 6 a partition disposed substantially transverse to its longitudinal direction 7 , The partition 7 is on the tubesheet 1 without being connected, because in the cases shown are the collection boxes 6 made of plastic, the partition 7 integral part of the collection box wall. The tube sheets 1 and the other components of the heat exchanger, however, have been made of a solderable metal. The partition 7 separates the collection box 6 in an entry-side part 6a and an exit-side part 6b on.

Due to the described features it can be seen that the heat exchanger shown is flowed through in a U-shape.

Other embodiments with an L-shaped or still other flow are possible, but not shown in the drawings.

In the embodiment shown are still two third openings 30a . 30b in the tubesheet 1 provided, one left and one right of the partition 7 , In both third openings 30a and 30b there is ever a second stability organ 3b , Also between the two second stability organs 3b you have, in the same way as between the flat tubes 2 , a corrugated rib 5 arranged.

As the 3 shows, you can between the partition 7 and the tubesheet 1 Place a seal to prevent bypass.

The 4 and 6a - 6c show that the ends of the stability organs 3b and or 3a with a contour 31 can provide, which makes the collection box 6 occurring flow is less or not affected.

Out 4 is also the result of the above-mentioned forming step at the ends of the second stability organs 3b visible to them in their openings 30 to secure force and form fit. The ends are formed here without Rezess. The same applies to the first stability organs 3a to, but not visible. Carrying out the forming step at the ends of the second stability organs 3b according to 4 is an optional measure. In other words, the ends of the second stability organs are enough 3b just in the openings 30a . 30b insert. Since the ends are fitting, there will be a tight soldering in the openings 30a . 30b also take place without performing the forming step.

Regarding the representations in the 6a - 6c is still significant that the positioning of the predetermined breaking points 8th in the stability organs 3a . 3b has a significant impact on the strength. In the 6a and 6c is the distance a to the tube sheet 1 much lower than in the 6b , The smaller distance a has shown significantly better results. Specifically, this distance was a 22 mm. As has been found, a convenient pitch is between about 10 and 70 mm. The greater distance a, as in 6b shown is about 170 mm.

Of the 6c also shows a special feature on both edges 32 of the stability organ 3b in its end area. The edges 32 were rounded to make a tight connection in the opening 30 of the tube bottom 1 to support.

In the 7 have all openings 10 . 20 . 30 in the tubesheet 1 a same size and shape.

The 5 shows, in contrast, that, for example, the openings 20 smaller than the openings 10 , in which the ends of the flat tubes 2 to sit. In the case according to 5 is provided, the first 10 and the third openings 30 identical form, what the 5 however, it is not apparent. In that case, of course, then the first and the second stability organs 3a . 3b not identical.

The 2 shows a soldered cooling network with two tubesheets 1 , with two first stability organs 3a , left and right, as well as with two second stability organs 3b , approximately in the middle. The cooling network belongs to the heat exchanger, which in the 1 is shown. However, it could also belong to another heat exchanger in its collection box 6 no partition 7 located. Also, the positioning of the second stability organs needs 3b not in the middle, but rather in a place where material breaks have often manifested before.

In the case shown, the first and second stability organs are 3a . 3b not identical. Out 2 it can be seen that the first stability organs 3a on both longitudinal edges with a bent flange 11 were provided. The second stability organs 3b are without such flanges 11 , So completely flat, has been trained, such as from the already mentioned 4 you can see.

To avoid the mentioned material fractures you can also use an open-ended section 4 in the tubesheet 1 provide. The potential for improvement is not as high as in the first alternative, but sufficient for many applications. It may, adjacent to the section 4 , a second stability organ 3b be arranged as in 9 you can see. The in the section 4 located flat tubes 2 can be considered dummy pipes 21 be educated. The section 4 may extend over three pipe distances b, for example. If necessary, you can - as shown - also on both sides of the section 4 a second stability organ 3b Arrange.

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 2628331 A [0002]

Claims (15)

Tubesheet ( 1 ) for a heat exchanger, with at least one row of first openings ( 10 ) for receiving tube ends of the tubes ( 2 ) of the heat exchanger, and with at least two second openings ( 20 ), one at each of two opposite ends of the tubesheet ( 1 ), for receiving and fixing one end of a first stability member ( 3a ), Such as a side portion of the heat exchanger, characterized in that within the series (from first openings 10 ) at least one third opening ( 30 ) is present, in each case one end of a second stability organ ( 3b ) is attached. Tube bottom according to claim 1, characterized in that the third opening ( 30 ) preferably of two relatively close to each other arranged third openings ( 30a . 30b ), with another second stability organ ( 3b ) whose end is in the second ( 30b ) of the third openings ( 30 ) is attached. Tubesheet ( 1 ) for a heat exchanger, with at least one row of first openings ( 10 ) for receiving tube ends of the tubes ( 2 ) of the heat exchanger, and with at least two second openings ( 20 ), one at each of two opposite ends of the tubesheet ( 1 ), for receiving and fixing one end of a first stability member ( 3a ), such as a side part of the heat exchanger, characterized in that within the row of first openings ( 10 ) an open-ended section ( 4 ) is present, which in the longitudinal direction of the tube bottom ( 1 ) extends over at least several pipe spacings (b). Tube sheet according to claim 3, characterized in that adjacent to the opening-free section ( 4 ) at least one third opening ( 30 ) in which one end of a second stability organ ( 3b ) is attached. Heat exchanger comprising, at least one row of tubes ( 2 ), for example flat tubes, and ribs ( 5 ) and two tubesheets ( 1a . 1b ), with a series of first openings ( 10 ) for receiving and fixing tube ends of the tubes ( 2 ) and collection boxes ( 6 ), which are connected to the tubesheets ( 1a . 1b ), and at least one first stability organ ( 3a ), for example a side part, the opposite ends of which are seated and fixed in second openings of the tubesheets, the second openings ( 20 ) at opposite ends of the tubesheets ( 1 ) are arranged, characterized in that the trained according to claim 1 or 3 and with the collecting boxes ( 6 ) connected tube sheets ( 1a . 1b ) with at least one third opening ( 30 ) for receiving one end of a second stability organ ( 3b ) are formed. Heat exchanger according to claim 5, characterized in that in one of the collecting tanks ( 6 ) a substantially transversely to the longitudinal direction arranged partition wall ( 7 ) is arranged on the tubesheet ( 1a ), and the collecting box ( 6 ) into an entry-side part ( 6a ) and an exit-side part ( 6b ). Heat exchanger according to claims 5 and 6, characterized in that preferably two third openings ( 30a . 30b ) in the tubesheet ( 1 ) are provided, a left and a right of the partition ( 7 ), with another second stability organ ( 3b ) is available. Heat exchanger according to claim 7, characterized in that (between the two second stability organs 3b ) one of the ribs ( 5 ), preferably a corrugated rib, which is arranged with its wave crests with the one second stability element and with its wave troughs with the other second stability element ( 3b ) is in direct contact. Heat exchanger according to one of the preceding claims, characterized in that the partition ( 7 ) and the second stability organs ( 3b ) approximately in the middle of the row of flat tubes ( 2 ) are arranged. Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger is a cooling liquid cooler for a motor vehicle, wherein the flat tubes ( 2 ) and the ribs ( 5 ) represent a cooling network, wherein the flat tubes of the cooling liquid and the ribs ( 5 ) are flowed through by cooling air. Heat exchanger according to one of the preceding claims, characterized in that the first and the second stability organs ( 3a . 3b ) are designed so that they allow a triggered by temperature change expansion in their longitudinal direction, for example, a partial separation cut or a bead or the like in the longitudinal direction compliant design. Heat exchanger according to one of claims 5-10, characterized in that the first and the second stability organs ( 3a . 3b ) with at least one predetermined breaking point ( 8th ) are equipped. Heat exchanger according to claim 12, characterized in that the predetermined breaking points ( 8th ) preferably relatively close to the tubesheet ( 1a ), for example 10-70 mm away from it. Heat exchanger according to one of the preceding claims, characterized in that the first and the second stability organs ( 3a . 3b ) are formed identically. Heat exchanger according to one of claims 1-13, characterized in that the first stability organs ( 3a ) with stiffening flanges ( 11 ) and that the second stability organs ( 3b ) are formed as substantially flat sheets.

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