WO2006133748A1

WO2006133748A1 - Fully-metal heat exchanger and method for its production

Info

Publication number: WO2006133748A1
Application number: PCT/EP2006/001487
Authority: WO
Inventors: Helmut Roll
Original assignee: Modine Manufacturing Company
Priority date: 2005-06-11
Filing date: 2006-02-18
Publication date: 2006-12-21
Also published as: KR100957665B1; EP1774245A1; KR20080025136A; ES2302323T3; BRPI0611998A2; US20080230213A1; EP1774245B1; DE502006000358D1

Abstract

The invention relates to a fully-metal heat exchanger comprising flat tubes (1), which have two narrow sides and two wide sides (2, 3), and comprising fins (4) which form a block together with the flat tubes, and comprising either at least one tube plate (5) and one collecting tank (6), with edges (10) of the collecting tank (6) being connected, for example soldered, to edges (20) of the tube plate (5), or at least one collecting tank (6) which contains the tube plate, and having projections (11) which are arranged at intervals. The invention leads to a heat exchanger which has a small installation space requirement while having comparatively good thermal properties in that, according to the invention, the projections (11) engage in the ends of the flat tubes (1) in the region of the narrow sides (2). The production method according to the invention accordingly provides that the projections (11) are inserted into the ends of the flat tubes (1) approximately in the region of the narrow sides (2).

Description

ALL-METAL HEAT EXCHANGER AND METHOD FOR THE PRODUCTION THEREOF

TECHNICAL AREA

The invention relates to a whole-metal heat exchanger, consisting of flat tubes with two narrow - and two broad sides and ribs, which together with the

Flat tubes form a block, and either at least have a tube plate and a collecting box, said edges of the collecting box with edges of the

Tube bottom connected, for example, are soldered, or at least one

Collecting box, which includes the tube sheet own, and with spaced projections. Furthermore, the invention relates to a production method for heat exchangers.

STATE OF THE ART

The heat exchanger described above is for example from the

DE 198 19 247 A1. The projections correspond there with openings in the tube sheets. As a result, a provisional cohesion of the items is provided before performing the soldering process. The effort for soldering

Auxiliary device can be significantly reduced. A certain disadvantage of the known

Heat exchanger is that still a clear supernatant of the

Pipe bottom over the ribbed flat-tube block is present, which is considered unnecessary

Space requirement could be considered. Furthermore, the ratio of the of

Flat tubes occupied cross-sections compared to the entire cross-section of the heat exchanger or its tube sheets are not optimal, so that in terms of efficient heat exchange improvements are possible.

PRESENTATION OF THE INVENTION

The object of the invention is to provide a heat exchanger which achieves a smaller space requirement with comparatively good thermal-technical values.

As a side effect, a production-friendly, especially a flexible

Design to be accepted.

The solution according to the invention results with respect to the all-metal

Heat exchanger by the use of the features of claim 1. The manufacturing method according to the invention is the subject of claim 22. It is provided that the projections in the region of the narrow sides in the ends of

Engage flat tubes. The projections are preferably located on the opposite longitudinal edges of the header tank. Preferably means in this case that embodiments may be provided, in which the projections are arranged on the longitudinal edges of the tube sheet, possibly associated with the disadvantage that the tube sheets are expensive and some other advantages do not occur. Another possible construction is that a metallic, frame-like additional part, which has the projections, is provided.

The manufacturing process leads to a number of advantages. The projections inserted into the flat tube ends on both opposite edges of the collecting box keep the flat tubes tension during the subsequent soldering process, so that the risk of so-called "collapse" of the flat tubes, with the consequence of insufficient solder joints with the tubesheet, has been substantially reduced Therefore, the use of flat tubes, the broad sides of which may have larger dimensions and thus avoids the production-technically complicated use of multiple rows of flat tubes in the direction of the depth of the flat tube fins block In addition, the above-mentioned advantages of the prior art are maintained, ie in particular the cost of soldering auxiliary devices is significantly reduced, since the inserted Vorsprün ge support the cohesion of the assembled items of the heat exchanger.

Because the flat tubes extend over the entire depth of the tubesheet, preferably even beyond, there is virtually no space that would not be available for heat exchange purposes. In other words, the flow-through cross-sectional area of the flat tubes is in a more favorable ratio to the total occupied by the tube sheet surface, which in turn is about equal to the relevant area, which is occupied by the entire heat exchanger.

In addition, the proposed heat exchanger has a higher process reliability in the production, as heat exchangers, which have no tube plates but instead of the tubesheets flared flat tube ends, as they are known for example from DE 19543 986 A1 or from much older documents. Either the flat tubes are with their narrow sides over the width of the tubesheet and in the protruding region, the projections engage in the ends of the flat tubes. Or the tube plate width is beyond the narrow sides of the flat tubes and in the protruding region, the projections engage in the ends of the flat tubes.

The first alternative mentioned, as mentioned, preferred because it is better to prevent the already mentioned "collapse" of the flat tubes, since in this case the edge of the headers with the projections from the outside rests on the edge of the tube sheet and therefore because the projections against Forces which act in the direction of the broad side, that is to say transversely to the longitudinal direction of the flat tubes, are particularly resistant, Moreover, this alternative also appears to be more favorable with regard to the creation of dense connections.

The projections each touch the narrow sides of the flat tubes from the inside and they are preferably soldered there.

The tubesheet preferably has in a conventional manner bent edges and openings for receiving a respective flat tube end. The openings, however, are proposed to extend into the bent edges. The tubesheets have only on the two longitudinal sides bent edges, so that they can be produced from a metal strip with any length. The tooling costs and the costs for conversion to different heat exchanger sizes are thereby significantly reduced.

The collecting box has frontal openings. Thus, each collection box turns out to be merely a sheet with two folds, which is also advantageous in terms of manufacturing technology.

The frontal openings of the collecting tank are closed by per se known side parts, which are extended beyond the length of the flat tubes out. The projections are appropriately shaped so that the insertion thereof into the ends of the flat tubes is assisted. An advantageous development provides to form the projections on the type of incisors. This design allows to better compensate for length tolerances in the flat tubes. Despite the inevitable length tolerances tight connections between the projections and the flat tube ends can be created. The all-metal heat exchanger can be used everywhere in the widest sense with advantages where a small space requirement with good heat exchange efficiency should be present. The inventor remembers to use such heat exchangers especially as air-cooled intercoolers in motor vehicles, but without excluding any other possible use, especially in the field of motor vehicles.

An all-metal heat exchanger is intended to be a heat exchanger whose constituents referred to in the claims are made of metal, preferably aluminum, regardless of whether later non-metallic parts which could be part of the system are attached to this heat exchanger or Not. For example, with all-metal heat exchangers, which are to be manufactured from formed sheet metal, it is relatively expensive to attach accessories and secure them.

The seated in the flat tube ends projections on a comb-like additional part, such as metal strips or the like., Which is connected to the wall of the header, keep the flat tubes during the subsequent soldering process to tension, so that the risk of the aforementioned "incidence Moreover, the advantages of the prior art are maintained, ie in particular the expense for soldering auxiliary devices is significantly reduced because the strips (Additional parts) have at the ends hooks that support the cohesion of the assembled items of the heat exchanger by grabbing over the side panels.

The headers can be formed in one piece or multiple parts. Striking is a part which has a U-shaped cross-section, wherein the base portion is provided with receiving openings for the pipe ends and the two legs form the two walls of the collecting tank. Once the walls have been reshaped and brought together to form a room, one-piece collection boxes are available. If the walls remain essentially flat, a second part is necessary for the formation of a closed space, which is why two-part collection boxes are then present. The receiving openings extend minimally into the walls of the collecting tank. These projections are also suitably shaped, so that the introduction of the same is supported in the ends of the flat tubes.

The additional part is a comb-like sheet metal strip, which is easy to process by forming technology to produce the additional part. For the purposes of the present invention, the term "strip" encompasses all possible physical formations, so that it is generally possible to speak of an additional part.The mentioned projections on the strips or additional parts can be first projections in the case that second projections are provided on the strip The second protrusions are then arranged between the first protrusions The second protrusions improve the assembly or the preparation of the heat exchanger for the following soldering process.

The inventive method for producing a whole-metal heat exchanger, wherein flat tubes and ribs are merged into a flat-tube fin block, after which tube plates are attached to the ends of the flat tubes and finally collecting tanks are attached with their edges to the edges of the tube sheets is characterized in that arranged on a component projections in the narrow sides of the flat tubes are inserted in the ends thereof.

Preferably, the longitudinal edges of the header are outside on the longitudinal edges of the tube sheet. The narrow sides of the flat tubes project over the longitudinal edges of the tube bottom, so that the protrusions located on the longitudinal edges of the collecting box can be inserted into the protruding flat tube regions. In this way, the projections hold the flat tubes in a tensioned state.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in two embodiments with reference to the accompanying drawings.

Fig. 1 shows an exploded view of the heat exchanger according to the invention;

2 shows a front view,

Fig. 3 is a plan view;

Figs. 4 and 5 are perspective views of a part of the heat exchanger;

Fig. 6 is an overall perspective view of the heat exchanger; Fig. 7 shows a detail of the flat tube;

Figs. 8 and 9 show an alternative embodiment;

FIG. 10 shows an exploded view of the invention

Heat exchanger. Figures 11 and 12 show perspective views of the finished heat exchanger. Figures 13 and 14 show perspective

Views of a part of the heat exchanger in a mounting situation. Fig. 15 shows an advantageous embodiment of the projections.

DESCRIPTION OF EMBODIMENTS

All illustrated individual parts of the heat exchanger are made of metal, preferably of aluminum or aluminum alloys, which is expediently coated with a layer of solder. The items such as flat tubes 1, ribs 4, tubesheets 5, 6 manifolds and side panels 30 are made of sheets, which, however, is not excluded that, for example, the flat tubes 1 could also be produced as drawn tubes. The flat tubes 1 have an approximately rectangular cross section, but the narrow sides 2 can also be curved slightly outwards. In the embodiment shown, internal inserts are located in the flat tubes 1. The flat tubes 1 are then stacked with the ribs 4 to form a flat tube fins block. At the ends of the flat tubes 1 tube sheets 5 are attached, with the ends of the flat tubes 1 are in openings 21 of the tube sheets 5, where later a dense solder joint is formed. Then the headers 6 are placed, and indeed, as shown in FIG. 4 reveals, while the projections 11 at the edges 10 of the manifolds 6 in the edge regions of the flat tubes 1, which projects through the slightly above the edges 20 of the tube sheet 5 Narrow sides 2 of the flat tubes 1 are formed, plugged. At the edge of the openings 21 in the tubesheets 5 there are preferably passages (not shown) which preferably point away from the collecting box 6 so that the flat tube ends do not protrude inwards in order to ensure low pressure loss of the medium flowing into the flat tubes 1. Between the openings 21 in the tube sheets 5 webs 22 are present. The webs 22 may be formed profiled to increase their rigidity. Finally, the side parts 30 are attached, which simultaneously close the frontal openings 60 of the collecting tanks 6. The side panels 30 each have a cup-shaped reshaped at their ends A closure piece that fits into the opening 60. By means of deformable holding elements 61, which engage in a slot 62 of the side parts, the side parts 30 are pre-fixed and hold the individual parts of the heat exchanger together. In this form, the heat exchanger is substantially prepared to carry out the CAB brazing process. All connections are made in a single pass in a brazing furnace.

The shape of the projections 11 is suitably adapted to the existing in the narrow sides 2 contour of the flat tubes 1, so that both the insertion is facilitated as well as dense solder joints are provided. This also certain manufacturing tolerances are absorbed. The distance between the projections 11 at the edge of the manifolds 6 corresponds to the distance between the flat tubes 1 in the row or with the height of the arranged between the flat tubes 1 ribs 4. Here, certain tolerances must be allowed, however, by the appropriate shape of the projections 11th can be compensated (see the description of FIGS. 15 and 16 below)

The headers 6 are particularly easy to manufacture, simple shape. Only two folds are necessary to form the two longitudinal walls and a transverse wall. For example, connecting pieces 70 can be easily realized by forming processes.

It should also be particularly production-friendly tube sheets 5 are used, which are made of endless tape and only need to be cut to the appropriate length, because they have no bevelled edges on their faces. There are therefore no expensive drawing tools needed. Here is an indication of Figs. 4 and 5 at. There it can be seen that at the edge 10 of the collecting tank 6 with the projections 11 comparable approach 100 is present. This cooperates with the corresponding cutout 101 on the edge 20 of the tube plate 5 and ensures there dense solder joints. It can also be seen from FIG. 5 that the openings 21 in the tubesheet 5 extend into the rim 20, which is indicated by the reference numeral 22. Therefore, the tubesheets 5 during assembly can also be pushed transversely to their longitudinal direction, or in the direction of the broad sides 3 of the flat tube ends, onto the same. In the prior art, this requires a movement in the longitudinal direction of the flat tubes. There is talk of "pulling up" the tubesheets. In particular, FIGS. 3 and 6 show, in a view of one of the side parts 30, that there are no lateral projections of the tubesheets 5 over the flat tube ribs block. The width of the side parts 30 corresponds approximately to the extent of the broad sides 3 of the flat tubes. 1

It should also be noted that the heat exchanger according to the invention allows a fairly easy access from the outside to soldering critical connections. Such critical connections are the flat tube tube bottom connections. If there are any leaks after the soldering process has been carried out, the corresponding points can be simply aftertreated and eliminated in a second soldering pass as they are largely accessible. In heat exchangers of the prior art, such a thing is often not possible, which is expressed by high reject rates. Fig. 7 shows schematically a single flat tube 1, namely a view of the flat tube end. Such flat tubes 1 are present in the desired number of heat exchangers. In each flat tube 1, two projections extend 11. The penetration depth needs to be only a few millimeters, 10 - 15 mm is already more than enough. Practically it will be less. It is understood that the one projection 11 is located at one edge of the header tank 6 and the other projection 11 at the opposite other edge 10 of the header tank 6. The projections 11 are close to the narrow sides 2 of the flat tube 1 from the inside. In the flat tubes 1 is an inner insert 80, as is typical in particular for charged with cooling air charge air cooler. In other applications, an indoor use is completely dispensed with. In practice, it is often difficult to insert the inner inserts 80 into the flat tubes 1 in such a way that as far as possible there is no bypass for the through-flow of charge air in the region of the narrow sides 2, which adversely affects the heat exchange. As shown in FIG. 7, the projections 11 have a favorable effect on the reduction of the harmful bypass, which comes into play as a further advantage of the invention. The small gaps in the corners of the flat tube 1 have their cause in the representation. In practice, they are not available or are securely closed during the soldering process. The mentioned gaps will also level when inserting the projections 11, because the projections 11 hold both broad sides 3 in the direction of the arrow under a certain tension. FIGS. 8 and 9 now show an alternative design, in which the projections 11 are arranged on the tubesheets 5. In this case, the tubesheets 5 must be mounted in the tube longitudinal direction, at the same time the projections 11 are inserted into the flat tube ends 1. Thereafter, the headers 6 and the side members 30 are attached and mounted.

At least in the embodiment shown in Figs. 10-14, one-piece header boxes 6 have been provided. In any case, however, it is provided that the collecting boxes 6 also include the tubesheets 5, so that therefore no classical tubesheets are provided as a single part, which can be taken from the mentioned figures. The collecting box 6 has a base section 106, from which two bent walls 107 of the collecting tank 6 depart. The walls 107 are deformed and they can be connected by means of a longitudinal weld, not shown, to form the header 6. In the base portion 106 receiving openings 21 are provided for the flat tube ends, which should therefore match the distances of the flat tubes 1 with the distances of the receiving openings 21. A quite striking feature is that the receiving openings 21 extend into the walls 107, d. H. they extend to just over the bending edge of the walls 107 at the base portion 106, which is clearly enough from the Fig. 14 at the reference numeral 22 can be seen. In the exemplary embodiments shown, a strip (additional part) 110 is provided on all the walls 107 of the two collecting boxes 6. On the walls 107 of a collecting box 6, the strips 110 with additional functions, such as e.g. formed with holding functions 90 for not shown accessories. The provision of strips 110 on all walls 107 is not an inevitable measure. In particular, it is advantageous to provide a strip 110 whenever additional functions 70 are to be fulfilled. In the present exemplary embodiment, there would in principle be no reason to dispense with the narrow strips 110 on the walls 107 of the left collecting tank 6, which do not have any additional functions, and to provide the solution described above for this purpose, ie. H. There, then, the projections 11 would be located directly on the walls 107 of the collecting tank 6 and there would be tubesheets as individual parts, as shown in the figures.

Another advantage of the strip 110 is shown in FIG. 12. One can see there that the strip 110, with the mentioned additional functions is formed, can also make a contribution to the strength of the collecting tank 6. It can be seen in FIG. 12 that the strip 110 extends over a substantial part of the wall 107 of the collecting box, and it is soldered to this wall 107. From Figs. 13 and 14, the formation of the strip 110 is more clearly seen with respect to the projections 11 spaced therefrom. The projections 11 can be provided with such a contour that the sliding of the same is facilitated in the flat tubes 1. Between the projections 11, which are first projections 11, are each second projections 12. As can be seen, a respective second projection 12 has been arranged between two first projections 11. The second protrusions 12 provide a counter-momentum of the strip 110 which otherwise, when the first protrusions 11 are in the flat tube ends, could tend to stand off the wall 107, which is undesirable. Since the second projections 12 rest against the ribs 4 from the outside, this is prevented, or at least counteracted. It is also apparent from FIGS. 13 and 14 that it is advantageous to form at the ends of the strip 110 a hook 13 which is adapted to hold the side member 30 firmly against the outer rib 4. This also supports the cohesion of the entire heat exchanger before soldering. Furthermore, this also suppresses the above-mentioned "sticking out" of the strip 110 from the wall 107. In addition, it can thereby refer to the brackets shown in Fig. 1 with Pos. 61 and 62, the side parts 30 in the frontal openings 60 of the collecting tank should be kept, be waived, which is also a manufacturing advantage.

Fig. 15 shows a section with only one projection 11. The projections 11 have been carried out in the manner of cutting teeth 111. As a result, length tolerances in the flat tubes, which are approximately in the range of +/- 1, 0mm are better absorbed. In these projections 11 sharp edges 112 were formed, which are also in the radii, d. h in the region of the transition from the projection 11 in the wall of the collecting tank 6 or the additional part or the tube bottom extend. The sharp-edged edges 112 somewhat intersect these ends upon insertion of the projections 11 into the flat tube ends and somewhat on the flat tubes in the upper length tolerance range, and "crimp" these ends slightly outwards The middle tube is slightly longer there than the other two tubes, the sharp edge of the projections 11 is produced for example by cold forming. The difference in thickness between the projections 11 and the wall of the flat tubes supports this procedure. The wall of the header 6, from which the projections 11 are formed, for example, may be about 1, 0 - be 2.0 mm thick while the thickness of the wall of the flat tubes may be in the range of 0.05 - 0.25 mm. Overall, the invention accordingly provides an innovative product which, compared to the state of the art, leaves only little to be desired.

Claims

1. All-metal heat exchanger, consisting of flat tubes (1) with two narrow - and two broad sides (2, 3) and ribs (4) which together with the flat tubes form a block, and either at least one tube plate (5 ) and a collecting box (6), said edges (10) of the collecting box (6) with edges (20) of the tube sheet (5) connected, for example, are soldered, or at least one collecting box (6), which includes the tube sheet has , and with spaced-apart projections (11), characterized in that the spacings of the projections (11) correspond to the spacings of the flat tubes (1), so that the projections (11) in the region of the narrow sides (2) in the ends of the flat tubes (1) intervene.

2. Whole-metal heat exchanger according to claim 1, characterized in that the flat tubes (1) with their narrow sides (2) over the width of the tube bottom (5) survive and in the projecting region, the projections (11) in the ends of the flat tubes (1) intervene.

3. Whole-metal heat exchanger according to claim 1, characterized in that the tube bottom width over the narrow sides (2) of the flat tubes (1) protrudes and in the protruding region, the projections (11) engage in the ends of the flat tubes (1).

4. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the projections (11) each touch the narrow sides (2) of the flat tubes (1) from the inside and are preferably soldered there.

5. All-metal heat exchanger according to one of the preceding claims, characterized in that the projections (11) are preferably arranged on the longitudinal edges (10) of the collecting tank (6).

6. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the tube sheet (5) in a conventional manner at the opposite longitudinal sides bent edges (20) and openings (21) for Each receiving a flat tube end (1), wherein the openings (21) extend into the bent longitudinal edges (20) into it.

7. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the tube sheets (5) only at the two longitudinal sides bent edges (20), so that they can be produced from a metal strip with any length.

8. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the collecting box (6) has frontal openings (60).

9. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the heat exchanger has per se known side parts (30) which extend over the length of the flat tubes (1) and the end-side openings (60) of the collecting boxes (6 ) close.

10. Whole-metal heat exchanger according to claim 1, characterized in that the projections (11) on the tube plate (5) are arranged, or that the projections (11) having a frame is used.

11. The all-metal heat exchanger according to one of the preceding claims, characterized in that the projections (11) on an additional part (110) are formed, which extends along the wall (107) of the collecting tank (6) and connected thereto is.

12. Whole-metal heat exchanger according to claim 1 and 11, characterized in that the collecting box (6) has two at a base portion (106) bent walls (107) which is formed with receiving openings (21) for the pipe ends.

13. All-metal heat exchanger according to claim 12, characterized in that the receiving openings (21) into the walls (107) of the collecting tank (6) enter.

14. All-metal heat exchanger according to claim 11 or 12, characterized in that the additional part (110) from the outside approximately flat against the wall (107) of the collecting tank (6).

15. All-metal heat exchanger according to one of the preceding claims 11 - 14, characterized in that the additional part (110) is equipped with other functions, such as holding functions (90) for accessories o. Ä ..

16. Whole-metal heat exchanger according to one of the preceding claims 11-15, characterized in that the additional part (110) may be provided with a contour which corresponds to the contour of the wall (107) of the collecting tank.

17. The all-metal heat exchanger according to one of the preceding claims 11-16, characterized in that the projections (11) are first projections (11), wherein the additional part (110) between the first projections (11) second projections (12). having.

18. Whole-metal heat exchanger according to one of the preceding claims 11 - 17, characterized in that the additional part (110) is formed at the end with a hook (13) or the like, suitable for fixing a side part (30) of the heat exchanger ,

19. All-metal heat exchanger according to one of the preceding claims, characterized in that the projections (11) are shaped, for example conical, that the introduction of the same in the ends of the flat tubes (1) is supported.

20. Whole-metal heat exchanger according to one of the preceding claims, characterized in that the projections (11) in the manner of cutting teeth (111) are formed.

21. All-metal heat exchanger according to one of the preceding claims, characterized in that the heat exchanger is preferably used as an air-cooled intercooler.

22. A method of making a whole metal heat exchanger comprising the steps of:

Flat tubes and ribs are combined to form a flat tube rib block; Tube sheets are placed at the ends of the flat tubes; Collecting boxes are set with their edges to the edges of the tube sheets, characterized in that arranged on a component projections (11) in the narrow sides (2) of the flat tubes (1) are inserted in the end.

23. A manufacturing method according to claim 22, characterized in that the protrusions (11) having longitudinal edges (10) of the collecting tank (6) are preferably applied from the outside to the edges (20) of the tube bottom (5), wherein the projections (11) in the ends of the flat tubes (1) are inserted.