DE102007008535A1 - Heat exchanger network, manufacturing process and roller mill - Google Patents

Abstract

The invention relates to a heat exchanger network of flat tubes (1) with two narrow and two broad sides (10, 20) and between the broad sides (20) of adjacent flat tubes (1) arranged ribs (3), wherein at least some of the successive flat tubes (1 ) can be flowed through in parallel by a means, wherein the other means approximately transversely through the fins (3) flows and wherein the two broad sides (20) of the flat tubes (1) have transformations to influence the flowing in the flat tubes means. According to the invention, the heat exchanging surfaces are enlarged in that the deformations are formed as corrugations (15) of the broad sides (20) of the flat tubes that run in the longitudinal direction (LR) of the flat tubes (1) and that the corrugations (15) are formed at least predominantly on the ribs (3 ) issue. Furthermore, a production method for flat tubes and a rolling mill are proposed, can be economically produced on the corrugated flat tubes of very thin-walled endless metal bands.

Description

The The invention relates to a heat exchanger network made of flat tubes with two narrow and two broad sides and with between the broad sides of adjacent flat tubes arranged ribs, wherein at least some of the successive flat tubes in parallel be flowed through by a means, wherein the other means about transverse to it flows through the ribs and wherein the broadsides the flat tubes have transformations to the flowing in the flat tubes To influence means. Furthermore, the invention relates to a production method for flat tubes, which are part of the heat exchanger network are and run on a roller mill becomes. Finally, the invention relates to a roller mill, with the manufacturing process for flat tubes is executable.

Heat exchanger, which have such heat exchanger networks belong for a long time the state of the art. In many cases, the transformations exist broadside from local dents or protrusions or similar. Such dents or protrusions can be disadvantageous because the connection - often a solder joint - between may be affected by the pipes and the ribs the heat transfer gets worse. Furthermore the training of dents is associated with costs.

In addition, heat exchangers with heat exchanger networks belong to the prior art, whose flat tubes are formed serpentine. In this case, the relatively long flat tubes bends by 180 °, wherein between successive bends, the ribs are arranged. In such heat exchangers, the flat tubes - in contrast to the above-mentioned heat exchanger networks - not flowed through in parallel. Rather, the means flows back and forth, so to speak, to pass through the individual flat tube sections between the bends and so to get from the inlet to the outlet. An example of many other heat exchangers of this type, the US 4 587 701 be removed. Such heat exchange networks can not be made as compact as you would like because of the mentioned numerous bends. The compactness is limited because the bending radii should not fall below a certain lower limit. Too small bending radii could lead to the closure of the flat tubes or the inoperability of the heat exchanger. These heat exchangers must often be said to have an excessively high pressure loss because of the numerous deflections of the medium flowing in the tubes. Furthermore, there are heat exchangers of the so-called tube bundle type, which have no heat exchange networks in the above sense. In these heat exchangers is a bundle, usually made of round tubes in a housing. The wall of the individual tubes may, for example, be spirally or otherwise deformed. The one means flows through the tubes and the other means flows in and out of the housing, passing through the spaces between the tubes of the bundle on the way from the inlet to the outlet. Such heat exchangers usually have no ribs between the tubes. Furthermore, these tubes have only wall deformations. These are usually designed so that the tubes still extend straight.

Naturally In contrast, there are also heat exchangers whose Tubes are not straight, but the example in the art are deformed by spirals. Between the individual courses of the helical spiral / n can be found ribs. However, such design principles are, for example, for in the motor vehicle existing radiators or the like, in which Cooling air flows through the ribs, not to use In any case, they are not common there.

The The object of the invention is a heat exchanger network design of the type described in the introduction, which is compact, which is competitive in terms of cost, and so too achieve very good values in terms of heat exchange efficiency can.

The Solution according to the invention results with respect the heat exchanger network with the features of the claim 1. The production process of the invention for the flat tubes of the heat exchanger network is Subject of claim 12. The manufacturing process is on a rolling mill running the features of claim 13.

With regard to the heat exchanger network is provided that the transformations are formed as running in or about in the longitudinal direction of the flat tubes corrugations of the broad sides of the flat tubes and that the corrugations at least predominantly rest against the ribs. This feature is inherent in that, of course, the narrow sides of the flat tubes have the corrugations, since they are part of the same Flachrohe. The corrugations of the broadsides and the narrow sides oscillate progressively about an imaginary plane that lies in the (not yet wavy) broadsides. In contrast, in the preferred embodiment, the undulations of the narrow sides do not oscillate about another plane lying perpendicular to the said plane, that is not about a plane lying in the narrow sides. Such a wave formation of the narrow sides is quite difficult for production of flat tubes and therefore not preferred in the present context. The heat exchanger network can have all types of flat tubes, those which have, for example, been produced by the extrusion process, or those which have been produced, for example, as welded flat tubes, or those which have been produced in accordance with the production process described further below. These latter flat tubes are preferably used in the proposed heat exchanger network, because they can be equipped due to the manufacturing process with extremely small wall thickness.

One according to the invention has further developed network a better heat exchange efficiency, because the heat exchanging Surfaces are enlarged. The proposed Heat exchanger network can work exactly without any problems be made as compact as a so-called high-performance cooling network the prior art, which has flat tubes without undulations. The Manufacturing costs are definitely competitive, especially when taking into account that the wall thickness the flat tubes was drastically reduced.

There the corrugations are preferably flat waves, which accordingly relatively large wavelengths and comparatively have relatively small wave heights, the pressure loss moves in very moderate areas. It can be influenced by the wave geometry become.

It is provided that the parallelism of the two broadsides of each flat tube obtained by the corrugations substantially remains.

It is more preferably provided that known in the art Parallelism of the arrangement of the flat tubes after the corrugation Essentially, Lives.

It Moreover, it is preferably provided that the broadsides, apart from the curls, otherwise are even, that is, they have no local dents or protrusions on. Therefore, despite the corrugations good soldering results expected between the flat tubes and the ribs.

It is provided in particular that the flat tubes from at least an endless, formed sheet metal strip on a roller mill or can be produced on a production line, and that the two narrow sides of the flat tubes are reinforced.

Around a decisive contribution to further increase the heat exchange efficiency It is further provided that the wall thickness of the flat tubes or the thickness of the at least one sheet metal strip in the range of 0.03 mm-0.20 mm is settled.

The Production process for flat tubes, which form part of a Heat exchanger network and are made of at least one strip endless strip material with at least one wall part and one with Shafts formed inner part, on one equipped with pairs of rollers Rolling line are produced, with the strip in Lengthwise through the rollers runs and reshaped is formed, wherein the formed with corrugated inner part between the formed Wall part is brought, after which closing the flat tube and finally the cutting of individual flat tubes performed is provided according to the invention, that after closing and before cutting one in the longitudinal direction the flat tubes running corrugation made the broad sides of the flat tubes becomes. The process ensures an economical production of the Flat tubes with very small wall thickness and in large quantities. The waves of the inner part yield flat tubes, which in their longitudinal direction have running channels. The channels can be discrete channels or those with each other in fluid communication.

With regard to the rolling mill for carrying out the method for producing flat tubes from at least one endless strip of strip material, wherein the rolling mill has at least one section for forming the strip, a section for joining the strip to the tube and a tube separating station, it is provided according to the invention, in that a forming station, with which a corrugation running in the longitudinal direction of the flat tubes of the broad sides of the flat tubes can be produced, is disposed between the joining section and the separating station. In order to produce the heat exchanger network from the flat tubes and the ribs, the same are stacked as known and loaded with corresponding compressive forces. The required compressive forces are slightly larger than in prior art heat exchanger networks. To this end, the inventor has found that it is much cheaper than ribs to use the so-called "flat-top fins." These are also corrugated fins whose crests and troughs are flat, in contrast to corrugated fins with rounded crests and troughs Such flat-top fins nestle better when pressed into the corrugated broad sides of the flat tubes and therefore lead to better soldering results.Here, however, a certain know-how is required, also seen from the aspect that the two broadsides The pressure forces mentioned must on the one hand be large enough so that the clinging of the ribs in the corrugations can pass, on the other hand the contact forces must not cause the two broad sides of the flat tubes to be pressed in or the flat tube womö Close in this In this context, the preferred flat tube with a corrugated inner part produced in accordance with the production method can be considered advantageous because the corrugated inner part can prevent the collapsing of the flat tubes or at least counteract the collapse. The compressive forces are preferably applied with pressure bodies (auxiliary devices) whose Oberflä surface is also formed wavy, the corrugations in the pressure bodies should correspond to the corrugations of the flat tubes.

The Thickness of the band from which the ribs are made also lies in the range of 0.03-0.09 mm. Is the pre-assembly process the heat exchanger network ends, the heat exchanger networks a soldering process, usually a CAB soldering process, subjected. Here are both the individual flat tubes as well firmly solder the flat tubes to the ribs. It understands Accordingly, that appropriate solder coatings and other requirements must be present. The material is with special Preference aluminum or aluminum alloy. It is easy though recognizable that other solderable metals as well are suitable.

Further Features are in the dependent claims, to which reference is made, which is why they are called at this point to be considered.

The Invention will now be described in embodiments with reference to the attached drawings / sketches described. The description may contain further features essential to the invention and their advantages.

The 1 and 2 show an undeformed or formed with corrugations flat tube. The 3 shows a section of a heat exchanger network according to the 4 , The 5 and 6 show the formation of curls. The 7 and 8th show moments of manufacture of the heat exchanger network. The 9 and 10 show a preferred flat tube. The 11 shows a roller mill in principle.

The flat tubes of the heat exchanger network are manufactured on a rolling mill or production line, which is located in the 11 is shown in principle. In this embodiment, the flat tubes are made from three "endless" metal bands There are also other embodiments, not shown, in which the flat tubes are made from a single or two sheet metal bands At this point, the applicant refers to her earlier applications with the file numbers DE 10 2006 006 670.7 . DE 10 2006 041 270.2 . DE 10 2006 002 789.2 , and DE 10 2006 035 210.6 , where flat tubes are described and shown from a single or from two metal bands, which are equally suitable to be used in the heat exchanger network.

Back to the existing embodiment, where from the one sheet metal strip, the one wall portion a of the flat tube is formed from the second sheet metal strip, the other wall portion b of the flat tube is formed, and from the third sheet metal strip, the inner part c. The 10 shows a finished flat tube in cross-section and the 9 shows a situation in the course of production of the flat tubes, namely the situation which is present approximately in the union section V of the rolling mill, in which the inner part c is brought between the two wall parts a, b.

From the 9 and 10 It can also be seen that the two wall parts a and b are identical. They have a larger arc at one edge and at the other edge they have a smaller arc. In the in the 9 shown moment the smaller arches are already finished and the larger arches are already preformed. The inner part c is initially placed obliquely between the two wall parts a, b, the wall parts a, b are moved towards each other and the flat tube is closed, in which the two larger sheets are placed around the smaller bows, whereby the narrow sides 10 be formed of the flat tube. This results in the narrow sides 10 a double wall thickness, the mentioned reinforcement of the narrow sides 10 represents. As the 10 shows, the narrow sides can 10 Be further reinforced by the fact that the two longitudinal edges of the inner part c in the narrow sides 10 issue. The longitudinal edges of the inner part c can, as can be seen, also be deformed with a small arc. The wall thickness of the two wall parts a, b may be in the range of 0.03 mm-0.20 mm or 0.15 mm. The wall thickness of the inner part c is preferably in the range of 0.03 mm-0.09 mm. By providing the corrugated inner part c, the flat tube has longitudinally extending channels 30 in the cross-section according to 10 you can see.

From the 11 It can further be seen that between the already mentioned joining station V and the separation station A arranged at the end of the rolling train, a forming station W is positioned for individual flat tubes with the longitudinal direction LR of the flat tube 1 running undulations 15 the broadsides 20 be formed. One possible embodiment of the forming station W is in the 5 shown in principle. It consists of three pairs of rollers. The first pair of rollers in the running direction or in the longitudinal direction of the flat tube is rigid, that is to say, it consists of two centrally mounted ones rotating rollers between which runs the endless flat tube and this stops at the predetermined height level. The immediately following pair of rollers is designed in the manner of swash plates with off-center axes of rotation. The rotation of this pair of rollers leads to oscillating movement of the gap between the two rollers, in which the flat tube runs, whereby the corrugations are formed. The third pair of rollers does the oscillating movements. In the embodiment shown as an alternative according to the 6 There are three pairs of rollers with central axes of rotation for producing the corrugations. The first pair of rollers is also rigid here. The middle and the last pair of rollers are vertically movable, that is, they also perform oscillating movements (double arrows), whereby the corrugations can be produced. In the 1 You can see a short section of a not yet provided with corrugations flat tube, as a view of the one narrow side 10 of the flat tube. In the 2 is shown in the same view a flat tube in which the corrugations 15 already trained. The dashed line shows the median plane of the flat tube, around which are the corrugations 15 commute progressively. As the 2 can imply the corrugations 15 formed in the illustrated embodiment with much larger wavelengths than amplitudes (wave heights), which is why the waves 15 are pretty flat. The waves 15 preferably run in the longitudinal direction LR of the flat tube. However, they may also have a slight angle to the longitudinal direction LR in their running direction, which is to be expressed by the wording in claim 1 "approximately in the longitudinal direction LR." The "running direction of the shafts" is understood to mean a direction perpendicular to the wave flanks be, so to speak, the flow direction in fluid waves.

The 4 shows a view of a heat exchanger network of flat tubes 1 and ribs 3 and the 7 and 8th should indicate the production of the network with sufficient clarity. In all these illustrations is from the flat tubes 1 only one of the narrow sides 10 recognizable. It is therefore viewed in the cooling air flow direction views. The cooling air flows through the corrugated fins 3 in the direction of not drawn depth of the cooling network. Furthermore, it can be seen from the illustration that the running direction of the corrugations of the corrugated ribs 3 in the running direction of the corrugations 15 the broad sides of the flat tubes lies. The ones with the curls 15 trained individual flat tubes 1 Now with corrugated ribs 3 the flat-top design alternately stacked. An auxiliary device 50 can be used as in the 7 and 8th shown to the grid, the flat tubes 1 and the ribs 3 to squeeze together. The auxiliary device 50 is also with a curl 51 trained, the curl 15 the flat tubes 1 should correspond approximately. The 3 shows an enlarged section of the net, where you can see that the type of ribs used 3 better on the broadsides 20 the corrugated flat tubes 1 clings as it corrugated ribs 3 could do with rounded wave crests and troughs. The geometry of the flat-top fins is slightly changed by the pressing, which also results from a comparison of the 7 and 8th is recognizable. The single flanks of the ribs 3 put under the action of forces approximately perpendicular to the surface of the wavy broadsides 20 , The otherwise often criticized disadvantage of flat-top fins easily buckling, is converted here to an advantage. In the state according to 8th the soldering process of the heat exchanger network is performed. (not shown) The ribs 3 are made of aluminum strip material of thickness 0.03 mm-0.09 mm. The rib height h ( 7 ) is approximately between 3 mm-9 mm or slightly more. The flat tubes have z. B. for a case of application as a radiator a small dimension d ( 9 ) of not much more than 1.0 mm, which is why pipes 1 and ribs 3 can be arranged very compact. The use of the mentioned small plate thicknesses and rib heights allow the arrangement of more tubes 1 and ribs 3 in the same space, which is reflected positively as enlargement of the heat exchanging surfaces. From the 3 is further evident that the parallelism of the two broadsides 20 each flat tube 1 through the curls 15 essentially preserved. It can also be seen that the parallelism of the arrangement of the flat tubes 1 Maintained in the network after their corrugation substantially.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 4587701 [0003]
• - DE 102006006670 [0021]
• - DE 102006041270 [0021]
• - DE 102006002789 [0021]
• - DE 102006035210 [0021]

Claims (16)

Heat exchanger network made of flat tubes ( 1 ) with two narrow sides and two broad sides ( 10 . 20 ) and between the broadsides ( 20 ) of adjacent flat tubes ( 1 ) arranged ribs ( 3 ), wherein at least some of the successive flat tubes ( 1 ) are flowed through in parallel by a means, wherein the other means approximately transversely to the ribs ( 3 ) and where the two broadsides ( 20 ) of the flat tubes ( 1 ) Have deformations in order to influence the medium flowing in the flat tubes, characterized in that the deformations as in or approximately in the longitudinal direction (LR) of the flat tubes ( 1 ) running corrugations ( 15 ) of the broadsides ( 20 ) of the flat tubes are formed and that the corrugations ( 15 ) at least predominantly on the ribs ( 3 ) issue. Heat exchanger network according to claim 1, characterized in that the parallelism of the two broad sides ( 20 ) of each flat tube ( 1 ) through the corrugations ( 15 ) is substantially preserved. Heat exchanger network according to claim 1 or 2, characterized in that the parallelism of the arrangement of the flat tubes ( 1 ) in the network essentially receives. Heat exchanger network according to one of the preceding claims, characterized in that the broad sides ( 20 ) have no local dents or protrusions. Heat exchanger network according to one of the preceding claims, characterized in that the flat tubes ( 1 ) are preferably produced from at least one endless, formed sheet-metal strip (c) on a roll train, and that the two narrow sides ( 10 ) of the flat tubes ( 1 ) are reinforced. Heat exchanger network according to claim 5, characterized in that the wall thickness of the flat tubes or the thickness the at least one sheet metal strip (c) in the range of 0.03 mm-0.15 mm is settled. Heat exchanger network according to claim 5, characterized in that the narrow sides ( 10 ) At least twice the thickness of the broadsides ( 20 ) exhibit. Heat exchanger network according to claim 1, characterized in that the ribs ( 3 ) are preferably corrugated ribs of the flat wave crest type and troughs. Heat exchanger network according to claims 1 and 8, characterized in that the shaft running direction of the corrugated fins ( 3 ) lies at least approximately in the direction of the corrugation of the broad sides of the flat tubes. Heat exchanger network according to the claims 1, 8 and / or 9, characterized in that the rib height or the wave height is located approximately between 3.0 and 9.00 mm is. Heat exchanger network according to claims 1 and 8, 9 and / or 10 characterized in that the thickness of the endless sheet metal strip from the ribs ( 3 ) are approximately in the range of 0.03 mm-0.09 mm is settled. Production method for flat tubes ( 1 ), which are part of a heat exchanger network and which are produced from at least one strip of endless strip material (Bb) having at least one wall part (a) and a corrugated inner part (c), on a roller train equipped with roller pairs, the strip being longitudinally ( LR) passes through the rollers and is deformed, wherein the corrugated inner part (c) between the deformed wall part (a, b) is brought, after which the closing of the flat tube and finally the cutting of individual flat tubes is performed, characterized in that closing and before cutting a longitudinal direction (LR) of the flat tubes ( 1 ) continuous corrugation ( 15 ) of the broadsides ( 20 ) of the flat tubes ( 1 ) is made. Roller mill for carrying out the method for producing flat tubes ( 1 in at least one endless strip of strip material, according to at least one of the preceding method claims, wherein the rolling line has at least one section (U) for forming the strip, a section (V) for joining the strip to the tube ( 1 ) and a separation station (A) for pipes (A) 1 ), and wherein between the joining portion (V) and the separating station (A) a forming station (W) is seconded, with a longitudinal direction (LR) of the flat tubes ( 1 ) continuous corrugation ( 15 ) of the broadsides ( 20 ) of the flat tubes ( 1 ) can be produced. Rolling train according to claim 13, characterized the forming station (W) contains at least one pair of rollers, that works on the principle of wobble waves. Rolling train according to claim 13 or 14, characterized in that the wobble shaft roller pair with a cooperates other roller pair. Rolling mill according to claim 13, characterized in that the forming station (W) three Roller pairs comprises, of which two pairs of rollers are movable to the corrugation ( 15 ) to be able to train.