ES2302323T3 - ENTIRE METALLIC HEAT EXCHANGERS AND PROCEDURE FOR MANUFACTURING. - Google Patents

Abstract

Entirely metallic heat exchanger consisting of flat tubes (1) with two narrow sides and two wide sides (2, 3) and fins (4) that, together with the flat tubes, form a block, and which has at least one tube plate (5) and a collecting drawer (6), being connected, for example welded, some edges (10) of the collecting drawer (6) with some edges (20) of the tube plate (5), or having at least one collecting drawer (6) that includes the tube plate, and with projections (11) arranged at certain distances, characterized in that the distances of the projections (11) correspond to the distances of the flat tubes (1), of so that the projections (11) located in the area of the narrow sides (2) fit into the ends of the flat tubes (1).

Description

Entirely metallic heat exchanger and manufacturing procedure

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Technical field Description

The invention concerns an exchanger of entirely metallic heat consisting of flat tubes with two sides narrow and two wide sides and fins that, together with the flat tubes, form a block, and which has at least one plate of tubes and a collecting drawer, being joined, for example soldiers, some edges of the collector drawer with some edges of the plate tubes, or that has at least one collector drawer that includes the plate of tubes, and with projections arranged at certain distances one of other. Also, the invention concerns a method of manufacture for heat exchangers.

State of the art

The heat exchanger previously described is known, for example, from document DE 198 19 247 A1. The projections correspond there with plate openings of tubes. This provides a provisional cohesion of the pieces individual before performing the welding procedure. The cost of the auxiliary device of welding. A particular inconvenience of the heat exchanger known is that there is still a clear blown projection of the tube plate with respect to the block of flat tube fins, which could be considered as a demand for unnecessary space. In addition, the proportion of cross sections occupied by tubes planes compared to the total cross section of the heat exchanger or its tube plates, so that they are Possible improvements regarding efficient heat exchange.

Exhibition of the invention

The problem of the invention consists in provide a heat exchanger that achieves a lower demand for space together with thermotechnical values comparatively good.

As a side effect, a Easy manufacturing design and especially also a design flexible.

The solution according to the invention is obtained with respect to the entirely metallic heat exchanger by the use of the features of claim 1. The manufacturing process according to the invention is subject to the claim 22. The projections of the area of the narrow sides fit the ends of the flat tubes. The projections are preferably at the edges opposite lengths of the collecting drawer.

The term "preferably" means in In this case, realizations may be provided in which projections are arranged, possibly joined, at the edges lengths of the tube plate, with the drawback that tube plates turn out to be more expensive and do not have some other advantages Another possible mode of construction is that an additional metal part is provided as a frame that Present outgoing.

The manufacturing process leads to a series of advantages. The protrusions plugged into the ends of the flat tubes located on both opposite edges of the collecting drawer keep the flat tubes under tension during the process of subsequent welding, which has significantly reduced the risk of the so-called "sinking" of flat tubes, with the consequence of insufficient welding joints with the plate tubes For this reason, the invention also allows the use of flat tubes whose wide sides may have larger dimensions and, consequently, avoids costly use - for the technique manufacturing - multi-row flat tubes in the direction of the depth of the flat-finned tube block. In  other words, by the invention can be provided heat exchangers in a capacity spectrum noticeably wider with a significantly smaller variation cost.

In addition, the advantages previously retained mentioned in the prior art, that is, it is reduced by particularly the cost of auxiliary devices of welding, since the protruding plugs contribute to the cohesion of the mounted individual parts of the exchanger hot.

Since the flat tubes extend throughout the depth of the tube plate - preferably they project even beyond this one - practically no space that is not available for the purpose of exchanging hot. In other words, the cross-sectional area of the flat tubes flown by fluid is in a more proportion favorable with respect to the entire surface occupied by the plate tubes, which is again approximately equal to the respective surface occupied by the entire heat exchanger.

In addition, the proposed heat exchanger Presents greater process safety during manufacturing than that of heat exchangers that do not have tube plates, but that have widened flat tube ends instead of tube plates, such as these are known, for example, by the document DE 195 43 986 A1 or by documents substantially previous.

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Flat tubes are projected flown with their narrow sides beyond the width of the tube plate and in the flown area the projections fit at the ends of the tubes blueprints. Or, the width of the tube plate is projected flown beyond the narrow sides of the flat tubes and in the area blown overhangs fit at the ends of the tubes blueprints.

As mentioned, the first alternative cited is the preferred one, since this way it can be better prevented "sinking" of the flat tubes already mentioned because in this case the edge of the collecting drawers with the projections it is applied from outside to the edge of the tube plate and, by this reason, the projections are especially resistant against forces acting in the direction of the wide side, that is, transversely to the longitudinal direction of the flat tubes. Also, this alternative seems to be more favorable as well. regarding the creation of hermetic joints.

The protrusions make contact from within with the respective narrow sides of the flat tubes and are there preferably soldiers.

The tube plate preferably has about folded edges in a manner known per se and openings for receive two ends of the flat tubes. However, the openings extend according to the proposal into the bent edges.

Tube plates have only tubes folded on the two longitudinal sides, so that these plates they can be manufactured from a sheet metal strip of any length. This reduces the costs of tools and readjustment costs to heat exchanger sizes different.

The drawer has front openings. Therefore, each collecting drawer is represented as only one sheet with two offsets, which is also advantageous in the aspect of manufacturing technique.

The front openings of the collecting drawer are they close by means of known side parts that are extended to beyond the length of the flat tubes.

The projections are shaped so convenient, which favors the introduction of them at the ends of the flat tubes. An advantageous improvement It plans to configure the projections as a cutting tooth. This configuration allows to better compensate for length tolerances in flat tubes Despite the inevitable tolerances of length, tight joints can be created between the projections and the ends of the flat tubes.

The all-metal heat exchanger it can be used with advantages in its broadest sense in all the sites where a reduced demand for space along with, at the same time, a good efficiency of heat exchange The inventor thinks about using such heat exchangers especially as air coolers of air-cooled power in motor vehicles, but without excluding any other possibility of use, especially in the field of motor vehicles.

An entirely metallic heat exchanger it must be a heat exchanger whose components mentioned in the claims are made of metal, preferably aluminum, with regardless of whether or not they are fixed to this exchanger later of heat other pieces not made of metal that could belong to the system. For example, in heat exchangers entirely Metals that must be manufactured from shaped sheets, are they can mount and securely attach accessories relatively complicated

The protrusions that settle at the ends of the flat tubes and that are present in an additional piece configured as a comb, such as a sheet metal strip or similar, which joins the wall of the collecting drawer, they keep the tubes planes under tension during the subsequent welding process, with what has been significantly reduced, also by the forecast of the additional piece, the risk of "sinking" above mentioned flat tubes, with the consequence of insufficient welding joints in the openings of accommodation. In addition, the advantages of the state of the technique, that is, the cost of auxiliary welding devices, since the strips (parts additional) have hooks at the ends that contribute to the cohesion of the mounted individual parts of the exchanger of heat because they cling to the parts lateral.

The drawers can be built in one piece or in several pieces. It highlights a piece that It has a U-shaped cross section, the base section with housing openings for the ends of the tubes and the two wings forming the two walls of the collecting drawer. When the walls are shaped and meet to form a compartment, one-piece collecting drawers are presented. When the walls are kept substantially flat, it is necessary a second piece to form a closed compartment, so two-piece collecting drawers are presented. The housing openings extend at least to the inside of the walls of the drawer.

These projections are also made up of convenient way, which favors the introduction of same at the ends of the flat tubes.

The additional piece is a strip of sheet metal way of comb that can be easily machined by techniques of conformation to manufacture the additional piece. The term "strap" means in the sense of the present invention all possible physical configurations, so you can talk like this in general an additional piece. The mentioned outgoing of the Straps or additional parts may be first protrusions in the case that some outgoing seconds are foreseen in the strap. The outgoing seconds are then arranged among the first outgoing The second projections improve assembly or heat exchanger preparation for the welding process next.

The method according to the invention for manufacture an entirely metallic heat exchanger, in which flat tubes and fins are joined to obtain a block of tubes flat-fins, after which plates are applied of tubes to the ends of the flat tubes and finally apply collecting drawers with their edges to the edges of the plates tubes, it is characterized because some projections arranged in a component, in the area of the narrow sides of the flat tubes, They plug into the ends of these.

Preferably, the longitudinal edges of the collecting drawer are applied on the outside to the longitudinal edges of The tube plate. The narrow sides of the flat tubes are projecting flown beyond the longitudinal edges of the plate of tubes, so that the projections located at the edges Longitudinal drawer can be plugged into areas flown flat tubes. In this way, the overhangs keep  to flat tubes in a stressed state.

Brief description of the drawings

The invention is described below in two Examples of embodiment with reference to the attached drawings, in those who:

Figure 1 shows a representation exploded from the heat exchanger according to the invention;

Figure 2 shows a front elevation;

Figure 3 shows a plan view;

Figures 4 and 5 show perspective views of a part of the heat exchanger;

Figure 6 shows an overview in heat exchanger perspective;

Figure 7 shows a detail of the tube flat;

Figures 8 and 9 show an embodiment alternative;

Figure 10 shows a representation exploded from the heat exchanger according to the invention;

Figures 11 and 12 show views in perspective of the heat exchanger finished manufacturing;

Figures 13 and 14 show views in perspective of a part of the heat exchanger in a mounting situation; Y

Figure 15 shows an advantageous configuration of the outgoing.

Description of embodiments

All individual pieces represented by Heat exchanger are metal, preferably aluminum or aluminum alloys, which has been conveniently coated with A layer of welding material. The individual pieces, such as flat tubes 1, fins 4, tube plates 5, collecting drawers 6 and side parts 30, are manufactured from sheets, but not it is excluded with this that, for example, flat tubes 1 are they could also manufacture in the form of embedded tubes. The pipes planes 1 have a cross section approximately rectangular, although narrow sides 2 may also be somewhat pumped out. In the case of embodiment shown, they find inside inserts 1 inside inserts. The flat tubes 1 are then stacked with fins 4 to form a block of flat tubes-fins. Some are applied tube plates 5 to the ends of the flat tubes 1, the ends of the flat tubes 1 being within openings 21 of the tube plates 5, where it is formed later a tight weld joint. The drawers settle later 6 collectors, specifically, as it allows to appreciate in particular the Figure 4, the projections 11 of the edges 10 of the the collecting drawers 6 in the edge areas of the flat tubes 1 which are formed by the narrow sides 2 of the flat tubes 1 slightly protruding from the edges 20 of the tube plate 5. At the edge of the openings 21 of the tube plates 5, preferably find mouths (not shown) that they preferably look out from the collecting drawer 6, so that flat ends do not protrude inward to provide a small loss of pressure of the medium entering the tubes planes 1. Between the openings 21 of the tube plates 5 are present souls 22. Souls 22 can be configured in a way profiled to increase its rigidity. Finally, the side parts 30, which close at the same time the front openings 60 of the collecting drawers 6. The parts lateral 30 have for this in each of its ends a respective closure piece shaped like a bowl that fits tightly in opening 60. By means of elements of conformable retention 61 that fit into a groove 62 of the lateral parts the lateral parts 30 are fixed previously and hold the individual parts of the exchanger together hot. In this way, the heat exchanger is substantially prepared for performing the procedure of hard welding CAB. All joints occur in one operation inside the welding furnace.

The shape of the projections 11 adapts conveniently to the contour of the flat tubes 1 existing in the narrow side area 2, so that the Introduction and welding joints are also provided hermetic Thus, certain tolerances of manufacturing. The distance of the projections 11 from the edge of the collecting drawers 6 corresponds to the distance of the tubes planes 1 of the row or with the height of the fins 4 arranged between the flat tubes 1. They have to be admissible here certain tolerances, but these can be compensated by the way suitable for projections 11 (see description below) of figures 15 and 16).

The collecting drawers 6 are of one Simple configuration especially favorable for manufacturing. Only two offsets are necessary to form the two longitudinal walls and a transverse wall. For example, it they can easily materialize connection fittings 70 by means of shaping procedures

Tube plates 5 must also be used especially favorable in its manufacture, which have to be produced from a continuous band and cut only still to the appropriate length, since they do not have edges Scalloped on its front sides. Therefore, I don't know They need expensive drawing tools. You are invited here to go to figures 4 and 5. It can be seen there that on the edge 10 of the drawer 6 there is a heel 100 comparable to those projections 11. This heel cooperates with the corresponding recess 101 of the edge 20 of the tube plate 5 and provides there joints Airtight welding. In figure 5 it can also be seen that the openings 21 of the tube plate 5 extend to the inside the edge 20, which is disclosed with the symbol of reference 22. For this reason, the tube plates 5 are plugged in also during assembly on the ends of the flat tubes transversely to the longitudinal direction of said plates or in the direction of the wide sides 3 of said ends. In the state technique is necessary for this a movement in the direction Longitudinal flat tubes. There is talk of "draft" of the tube plates.

Particularly Figures 3 and 6 show in a view of one of the side parts 30 that do not exist side blown projections of tube plates 5 to more beyond the flat-finned tube block. The width of the side parts 30 corresponds approximately to the measurement of the wide sides 3 of the flat tubes 1.

It should also be noted that the heat exchanger heat according to the invention allows fairly easy access from out to critical unions in the technical aspect of welding. Such critical joints are the joints between the flat tubes and the tube plates. If there are a lack of tightness after of the completion of the welding process, the sites corresponding, since they are accessible in a very large degree, they can then be treated in a simple way and eliminated in a second welding pass. In exchangers of heat of the state of the art it is common that something similar does not possible, which manifests itself in high waste rates.

Figure 7 schematically shows a tube individual plane 1, specifically looking towards the end of said flat tube Such flat tubes 1 are present in the heat exchanger in a desired number. Two projections 11 se extend into each flat tube 1. The depth of penetration has to be only a few millimeters, being already 10 to 15 mm more than enough. In practice, this depth It will be even smaller. It is understood that a projection 11 is in one edge of the collecting drawer 6 and that the other projection 11 is located on the other opposite edge 10 of said collecting drawer 6. The projections 11 are applied tightly from the inside to the sides narrows 2 of the flat tube 1. In the flat tubes 1 there is a internal insert 80, such as this is typical especially for feed air coolers requested with air from refrigeration. In other cases of use it is dispensed with completely of an internal insert. In practice, it is often difficult to insert the internal inserts 80 into the flat tubes 1 so that, if possible, it does not originate in the area from the narrow sides 2 no bypass for the air of circulating feed that has a negative impact on the heat exchange As Figure 7 shows, the projections 11 have a favorable impact on the reduction of the harmful derivation, which manifests as an additional advantage of the invention. The small slits in the corners of the flat tube 1 They have their origin in representation. In practice, these do not they exist or close securely during the welding process. The slits mentioned also flatten when the projections 11, since these projections 11 keep both sides widths 3 under some tension in the direction of the arrow.

Figures 8 and 9 now show a design alternative in which the projections 11 are arranged in the tube plates 5. In this case, tube plates 5 have to creep in the longitudinal direction of the tubes, entering at the same time the projections 11 at the ends of the flat tubes 1. Next, the collecting drawers 6 and the side parts 30.

At least in the embodiment example that shown in figures 10 to 14, collecting drawers 6 are provided one piece. However, it is foreseen in any case that the collecting drawers 6 also comprise the tube plates 5, so there are no planned classic tube plates in the form of individual pieces, which can be deduced from the figures mentioned. The drawer 6 has a base section 106 of the two folded walls 107 come out of the collecting drawer 6. The walls 107 are shaped and can be joined by means of a longitudinal weld seam not shown to form the collecting drawer 6. On the base section 106, some housing openings 21 for the ends of the flat tubes, so the distances of the flat tubes 1 must match with the distances of the accommodation openings 21. One quite prominent feature is that the openings of housing 21 extends to the inside of walls 107, that is, they extend up to a little above the edge of folded from the walls 107 in the base section 106, which may Appreciate clearly enough in the reference symbol 22 of Figure 14. In the examples of embodiment shown, they find two straps (additional pieces) 110 in all walls 107 of the two collecting drawers 6. On walls 107 of a manifold drawer 6 has been configured the strips 110 with functions additional, such as with retention functions 90 for Accessories not shown. The forecast of strapping 110 in all 107 walls is not a forced measure. It is advantageous to provide a strap 110 especially as long as functions must be performed additional 70. In the present embodiment, nothing would speak in principle against dispensing with the narrow strips 110 in the walls 107 of the left collecting drawer 6, which do not they perform additional functions, and provide instead there the solution described above, that is, then the protrusions  11 would be arranged there directly on the walls 107 of the 6 drawer and tube plates would be present as individual pieces, as shown in the figures.

Another advantage of strapping 110 is apparent from the Figure 12. It can be seen there that the strip 110, which is formed with the additional functions mentioned, can contribute also to the resistance of the collecting drawer 6. It is seen in the figure 12 that the strip 110 extends over a considerable part of the wall 107 of the collecting drawer and is welded with this wall 107. It you can see more clearly in figures 13 and 14 the configuration of the strip 110 with respect to the projections 11 arranged in it at certain distances. The projections 11 can be provided of an outline such that sliding thereof is facilitated into the flat tubes 1. Between the projections 11, which are first projections 11, there are respective seconds 12 outgoing. As you can see, every second outgoing 12 has been arranged between two first projections 11. The second projections 12 cause a moment of antagonistic force of the strip 110 which, of if not, when the first projections 11 are inside of the ends of the flat tubes, it could have a tendency to move away from the wall 107, which is undesirable. Since the outgoing seconds 12 are applied from outside to the respective fins 4, this is prevented or at least counteracted.

It also appears from figures 13 and 14 that it is advantageous to form a hook 13 at the ends of the strip 110 which is suitable for firmly holding the side part 30 against the outer fin 4. It also contributes to the cohesion of the full heat exchanger before welding. Equally, the "estrangement" is also suppressed before mentioned of the strip 110 with respect to the wall 107. In addition, it can be dispense with the clamps shown with positions 61 and 62 in figure 1, which should keep the side parts 30 in the front openings 60 of the collecting drawer 6, which It is also an advantage for the manufacturing technique.

Figure 15 shows a fragment with only a projection 11. The projections 11 have been constructed in the manner of cutting teeth 111. The tolerances of length in flat tubes, which are approximately in the range of +/- 1.0 mm. In these projections 11 edges have been formed 112 of sharp edge that also extend in the radii, is that is, in the area of the transition from the projection 11 to the wall of the 6 drawer or the additional part or tube plate. In flat tubes that are in the upper tolerance range of length, the edges 112 of sharp edge cut and open somewhat the ends of these flat tubes when introducing the protrusions 11 in they and "bead" a little these ends out. This it can be seen well in reference k of figure 16. The tube Central is there somewhat longer than the two outer tubes. The constitution of the projections 11 with live edges is obtained, by example, by cold forming. The difference of thickness between the projections 11 and the wall of the flat tubes Contributes to this way of proceeding. The wall of the collecting drawer 6, in which, for example, the protrusions 11 are formed, can have a thickness of approximately 1.0 to 2.0 mm, while the wall thickness of flat tubes may be in the range from 0.05 to 0.25 mm.

Accordingly, the invention provides in set an innovative product that, compared to the state of the technique, leave only a few desires open.

Claims (23)

1. Entirely metallic heat exchanger consisting of flat tubes (1) with two narrow sides and two wide sides (2, 3) and fins (4) that, together with the flat tubes, form a block, and which presents the less a tube plate (5) and a collector drawer (6), for example being welded, some edges (10) of the collector drawer (6) with some edges (20) of the tube plate (5), or which has at least one collecting drawer (6) that includes the tube plate, and with projections (11) arranged at certain distances, characterized in that the distances of the projections (11) correspond to the distances of the flat tubes (1) , so that the projections (11) located in the area of the narrow sides (2) fit the ends of the flat tubes (1). 2. An entirely metallic heat exchanger according to claim 1, characterized in that the flat tubes (1) are projected flown with their narrow sides (2) beyond the width of the tube plate (5) and in the flown area the projections (11) fit the ends of the flat tubes (1). 3. Entirely metallic heat exchanger according to claim 1, characterized in that the width of the tube plate is projected flown beyond the narrow sides (2) of the flat tubes (1) and in the flown area the projections (11) they fit at the ends of the flat tubes (1). 4. An entirely metallic heat exchanger according to one of the preceding claims, characterized in that the projections (11) make contact from within with the respective narrow sides (2) of the flat tubes (1) and are preferably welded there. 5. Entirely metallic 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 drawer (6). 6. An entirely metallic heat exchanger according to one of the preceding claims, characterized in that the tube plate (5) has, in a known manner, on the opposite longitudinal sides, bent edges (20) and openings (21) for receiving both ends of the flat tubes (1), the openings (21) extending to the inside of the bent longitudinal edges (20). 7. An entirely metallic heat exchanger according to one of the preceding claims, characterized in that the tube plates (5) only have bent edges (20) on the two longitudinal sides, so that they can be manufactured from a sheet metal strip of any length. 8. Entirely metallic heat exchanger according to one of the preceding claims, characterized in that the collecting drawer (6) has front openings (60). 9. An entirely metallic heat exchanger according to one of the preceding claims, characterized in that the heat exchanger has known side parts (30) that extend along the entire length of the flat tubes (1) and close the front openings ( 60) of the collecting drawers (6). 10. An entirely metallic heat exchanger according to claim 1, characterized in that the projections (11) are arranged in the tube plate (5) or that a frame is used that has the projections (11). 11. An entirely metallic heat exchanger according to one of the preceding claims, characterized in that the projections (11) are formed in an additional part (110) that extends along the wall (107) of the collecting drawer (6) and which It is linked with this one. 12. Entirely metallic heat exchanger according to claims 1 and 11, characterized in that the collecting drawer (6) has two walls (107) folded in a base section (106) that is formed with housing openings (21) for the ends of the tubes. 13. Entirely metallic heat exchanger according to claim 12, characterized in that the housing openings (21) extend to the interior of the walls (107) of the collecting drawer (6). 14. Entirely metallic heat exchanger according to claim 11 or 12, characterized in that the additional part (110) is applied from outside, approximately flat, to the wall (107) of the collecting drawer (6). 15. Entirely metallic heat exchanger according to one of the preceding claims 11 to 14, characterized in that the additional part (110) is equipped with additional functions, for example with retention functions (90) for accessories or the like. 16. Entirely metallic heat exchanger according to one of the preceding claims 11 to 15, characterized in that the additional part (110) can be provided with an outline corresponding to the wall contour (107) of the collecting drawer.

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17. Entirely metallic heat exchanger according to one of the preceding claims 11 to 16, characterized in that the projections (11) are first projections (11), the additional part (110) having second projections (12) arranged between the first projections (eleven). 18. Entirely metallic heat exchanger according to one of the preceding claims 11 to 17, characterized in that the additional piece (110) is formed at the end with a hook (13) or the like that is suitable for immobilizing a lateral part (30) of the heat exchanger. 19. Entirely metallic heat exchanger according to one of the preceding claims, characterized in that the projections (11) are conformed, for example, conically, so that they are introduced at the ends of the flat tubes (1). 20. Entirely metallic heat exchanger according to one of the preceding claims, characterized in that the projections (11) are configured in the manner of cutting teeth (111). 21. Entirely metallic heat exchanger according to one of the preceding claims, characterized in that the heat exchanger can preferably be used as an air-cooled feed air cooler. 22. Method of manufacturing an entirely metallic heat exchanger with the following steps: flat tubes and fins are joined to obtain a block of flat tube-fins; tube plates are applied to the ends of the flat tubes; and collecting drawers with their edges are applied to the edges of the tube plates, characterized in that projections (11) arranged in a component located in the area of the narrow sides (2) are connected at the ends of the flat tubes (1) ) of said flat tubes. 23. Manufacturing method according to claim 22, characterized in that the longitudinal edges (10) of the collecting drawer (6) having the projections (11) are preferably applied from outside to the edges (20) of the tube plate (5) , so that the projections (11) are plugged into the ends of the flat tubes (1).