DE10343239A1 - Heat exchanger - Google Patents

Abstract

Heat exchanger with tubes and at least one collecting box, wherein the collecting box comprises at least one tubesheet with passages, wherein the passages are bordered by flanks.

Description

The The present invention relates to a heat exchanger, in particular a Intercooler for a Motor vehicle.

Around can achieve an increase in performance of an internal combustion engine, can the combustion to be supplied For example, air can be compressed with a turbocharger before it is fed to the combustion chambers of the internal combustion engine. The compression of the air, however, at the same time heating them with, who for an optimal sequence of the combustion process is disadvantageous. For example This can make a premature Ignition or an increased Nitrogen oxide emission triggered become. To the detrimental consequences of the superheated supplied To avoid air, a turbocharger is designed as a charge air cooler Heat exchanger downstream, with which the compressed air before its combustion to a permissible Temperature cooled can be.

An intercooler is for example in the DE 197 57 034 A1 described. In the local heat exchanger, the hot air is introduced into a first collecting channel of the heat exchanger, where it is distributed and flows into flat tubes, which open into the collecting channel. The flat tubes are next to each other, and arranged with the long sides of their cross-section containing side surfaces parallel to each other and form a Strö mungsweg, is passed through the cooling air. In the flow path cooling fins are arranged between the flat tubes, which effect an effective heat exchange between the flat tubes and the cooling air flow. After passing through the cooling air flow, the flat tubes open into a second collecting channel, which supplies the incoming therein, cooled, compressed charge air combustion in the engine.

at heat exchangers such as in particular such intercoolers, the tubes are common in openings a tube bottom plugged and soldered fluid-tight. With each loading with compressed air is subject to this solder joint due to faster pressure changes high mechanical loads. Especially the narrow sides of flat tubes fulfill not the increasing strength requirements, which causes leaks in particular in the sides of the tubesheet facing areas of such pipe-ground connections can result.

One easy way to increase the strength of tube-to-ground connections increase, is a use of pipes and / or tube sheets with higher Wall thickness or from outside and / or inner ribs with higher Material thickness. The enlarged mechanical stability is in both cases obvious, the one for it needed However, additional expenditure on material costs and weight is very high.

Other Deal with solutions with a reduction in the mechanical stress on the pipe-floor joints by using tie rods in the charge air boxes. Stabilize this tie rod the charge air boxes and thereby relieve the pipe-ground connections, but bring an increase the cost of materials and the pressure loss caused by the intercooler with himself.

The The object of the invention is a heat exchanger, in particular a Intercooler, to provide, in the mechanical loads of pipe-ground connections without Extra expense of material can be reduced.

These Task is performed by a heat exchanger solved with the features of claim 1.

According to claim 1 has a heat exchanger Tubes on which are suitable, flows through a first medium and from flows around a second medium to become so that heat from the first to the second medium or vice versa. At least one at least one collecting box communicating with the pipes a tube sheet, wherein the tube sheet is formed substantially flat is and passages has, in which the pipes to a formation of the communicating Connection with the collection box can be inserted.

basic idea The invention is the areas surrounding the passages of the Pipe bottom in the form of depressions or elevations geometric so that the by trains each at the "bottom" of a depression or arranged on the "summit" of a survey are. As a result, the passages are circumferentially flanks, namely the Flanks of the depressions or elevations, edged. By such a geometric shape, especially by the circumferential Design of the flank, the bending stiffness of the tube sheet across from increased in a flat tube sheet in several directions, so that deformations, which occur due to a pressure load of the collecting tank, reduced be, thereby making connections of pipes to the tubesheet mechanically be relieved. Preferably, the depressions or Elevations so wide that the Flanks of two adjacent passes to form a reinforcing bead contiguous.

The inventive design of the heat exchanger whose mechanical strength and thus its life he increases, without the need for extra work on material or parts number would be necessary.

advantageous embodiments The invention are the subject of the dependent claims.

According to one preferred embodiment, the flanks respectively over the Perimeter of a passage on a substantially constant width. As a result, the bending stiffness of the tubesheet in all directions increased substantially uniformly.

According to one advantageous embodiment the tubes are formed as flat tubes and in one or more Arranged rows. The passages as well as the intermediate beads formed by the flanks are then elongated according to the pipe cross-sections.

Prefers the flanks each have a rounding with approximately constant radius of curvature or several curves with different radii of curvature. This will a particularly good approach to a semicircular Cross-section of Sikken lying between the passages achieved resulting in a particularly high bending stiffness.

According to one another embodiment the flanks each comprise one or more planar regions, So that the Flanks or the sikken between the passages one have faceted shape. This allows a safe production with low manufacturing tolerances.

Especially Preferably, the at least one planar region forms with the respective one Pulling an obtuse angle. This means that the passage even an extra increase the flexural rigidity of the tubesheet causes, as the passage in the same direction points as the depression or elevation, to the "reason" or on the "peak" of the passage located.

Of the Angle between the flat region of the flank and the passage is preferred between 30 ° and 60 °, especially preferably about 45 °. In this case, a width of the edge may be about equal to a height the flank so that one especially high stability opposite the tube bottom Deformations results.

According to one advantageous embodiment, the passages from the at least one collection box out. This may have the advantage that each one to an edge the tube bottom adjacent area of the flanks in a possibly set up Edge of the tube bottom passes, resulting in a further increase in strength of the tube sheet.

According to one preferred development of the heat exchanger according to the invention is designed as a charge air cooler, which is particularly preferably used in motor vehicles. Especially points the intercooler two collection boxes on, one of which for distribution and a second for collection is provided by charge air. Advantageously, each of the collection boxes exactly on a tube bottom, with a number of tube openings is provided. Also, it is beneficial to have a series of flat tubes to use with intermediate, in particular soldered corrugated fins, because this achieves an increased heat transfer area becomes. As a cooling medium is preferably air, although other cooling media such as water or coolant are conceivable.

According to one advantageous embodiment the invention, a tube sheet is prepared by means of a Forming process one or more edge areas of a flat sheet placed and placed adjacent recesses in the sheet become. The recesses each have a substantially flat surface and one the base area bordering and circumferential flank. Subsequently, the bases of the Wells by means of a pull-through method to form by trains punctured. Should pipes be inserted from the side of the recesses into the tubesheet be particularly preferred insertion bevels to facilitate a such insertion of pipes in the passages.

manufacturing technology advantageous is an embodiment of a tube plate with a or multiple rows of like flanks and / or passages.

The Invention will now be described with reference to exemplary embodiments with reference explained on the drawings. Show it:

1 an oblique view of a tube sheet,

2 a side view of a tube plate with inserted tube,

3 a longitudinal section through a tube sheet with tubes inserted,

4 a longitudinal section through a tube bottom cutout with inserted tube and

5 a longitudinal section through a tube bottom cutout with inserted tube.

1 shows a section of a heat meübertrager 10 in a perspective view. A collection box 20 for the distribution of a first medium consists of a tube sheet 30 and a box lid, not shown, at a common interface 50 welded together. The box lid is here in the tubesheet 30 put into it. But it is also conceivable, the box lid on the tubesheet 30 aufzustecken or otherwise on the tube sheet 30 to install. In other embodiments, not shown, a tube sheet and a box lid by soldering, bonding or positively connected with each other or in one piece or in one piece, that is, for example, consisting of a formed plate formed.

The tube sheet 30 has a pipe opening 60 on, its edge 70 as so-called passage from the collecting box out is transformed. A substantially rectangular flat tube is in the tube opening 60 pluggable and with the tubesheet 30 solderable or weldable. Not shown are corrugated fins which are adjacent to both sides of the flat tube, also not shown, and are soldered to the latter, so that a heat transfer is increased from flowing through a pipe on a pipe and the ribs flowing around medium or vice versa. Overall, the heat exchanger includes 10 a whole series of alternating flat tubes and corrugated fins, which form a so-called tube-rib block.

Will the collection box 20 pressurized with a medium, the collection box deforms 20 possibly such that its cross-sectional shape approaches a circular shape. To counteract such deformation, the passage is 70 from a circumferential flank 90 bordered, which adjoins the passage at an obtuse angle. The flank has a width that surrounds the passage 70 is substantially constant. This results in a uniform stiffening of the tube sheet 30 both in tube plate longitudinal direction by the flank areas 91 . 92 on the front sides of the passage 70 as well as in tube sheet transverse direction by the flank areas 93 . 94 on the long sides of the passage 70 ,

This results in a lower deformation of the tube sheet 30 under pressure of the collecting tank 20 , This reduced deformation of the tube bottom 30 brings a reduction in the mechanical load of the pipe or the pipe-floor connection with it. In particular, the mechanically most stressed at such pressure-induced deformations end faces of the flat tube are relieved.

As in the side view of the heat exchanger 110 in 2 it can be seen, is the pipe 120 so far into the pipe opening 160 put in that an upper edge area 121 of the pipe 120 over the tubesheet 130 protrudes. This will make a good use of the pipe 120 facing, invisible inner surface of the passage 170 guaranteed as a contact surface for a pipe-floor connection. This is for example a dense soldering. To avoid an unnecessarily high pressure drop of the first medium via the heat exchanger, the supernatant of the tube 120 over the tubesheet 130 to be kept as low as possible. For this reason, there is the pipe opening 160 in a substantially flat central region 131 of the tube bottom 130 ,

The passage 170 is from a flank 190 bordered, whose end faces 191 . 192 on the one hand at an obtuse angle in the passage 170 and on the other hand, also at an obtuse angle, in an erected edge area 132 of the tube bottom 130 pass. By the associated S-shaped cross section of the tube sheet 130 in the area of the cover connection surface 150 - border area 132 - Flank area 191 / 192 - Draft 170 gets the pipe 120 or the pipe-floor connection an additional load reduction.

3 shows a further embodiment of a heat exchanger 210 partially in a longitudinal section. Tube 220 . 221 . 222 stuck in pullouts 270 . 271 . 272 a tube bottom 230 , To a pressure drop through the heat exchanger 210 and among other things through the pipes 220 . 221 222 flowing medium over the heat exchanger 210 reduce the passages 270 . 271 . 272 from the collection box, not shown, and the pipes 220 . 221 . 222 do not protrude above the tubesheet 230 or its passages 270 . 271 . 272 out.

The passages 270 . 271 . 272 are by flanks 290 bordered, each having a flat portion 295 exhibit. The flat part area 295 closes with the passage 270 an obtuse angle, whereby the stiffening effect of the flank 290 formed depression in the tube sheet 230 is additionally reinforced. The flanks 290 border directly to each other, so that beading 299 be formed in 3 can be seen in their cross section. As clearly shown in this cross section, the beads have 299 no horizontal, between the flanks 290 lying on areas.

Advantageously, the width b of the height h of the flanks 290 similar, more preferably about the same. For this reason, the angle between the flat portion is 295 the flank 290 and the passage 270 about 45 °. For the beads 299 this results in a bead angle α of about 90 °, with a particularly high stiffening effect of the beads 299 connected is.

4 , shows the detail of a modified embodiment of the heat exchanger 3 , Here stands the pipe 320 about the passage 370 but ends below a surface 335 of the tube bottom 330 , This results in increased manufacturing reliability with regard to a fluid-tight connection between the tubesheet 330 and the tube 320 , For example, a solder joint is through to the soldering gap 375 additionally added soldering gap 376 improved. The soldering gap serves at the same time as an insertion bevel for facilitating the insertion of the tube 320 in the tubesheet 330 ,

In contrast, stands out in the in 5 illustrated embodiment, the tube 420 about the passage 470 and over a surface 435 of the tube bottom 430 out. Because of the associated greater tolerances with respect to the length of the tube 420 follows a further increase in manufacturing safety.

Claims (10)

Heat exchanger with tubes and at least one collecting box, wherein the collecting box comprises at least one tubesheet, the tube sheet passages into which the tubes are inserted, characterized in that the passages are enclosed by a respective circumferential flank, wherein the flanks of two adjacent passages adjoin one another to form a bead. Heat exchanger according to claim 1, characterized in that the flanks each over the circumference a passage having a substantially constant width. Heat exchanger according to claim 1 or 2, characterized in that the tubes arranged in at least one row flat tubes are that the passages accordingly the tube cross-sections oblong are trained and that the Flanks of the passages under formation of elongated Beading border. Heat exchanger according to one of claims 1 to 3, characterized in that the flanks each one Rounding with approximately constant radius of curvature exhibit. Heat exchanger according to claim 4, characterized in that the edge in each case a plurality of curves having different radii of curvature. Heat exchanger according to one of claims 1 to 5, characterized gekennnzeichnet that the flanks each at least have a flat area. Heat exchanger according to claim 6, characterized in that the at least one plane Area with the respective passage an obtuse angle, in particular an angle between 30 ° and 60 ° forms. Heat exchanger according to one of claims 1 to 7, characterized gekennnzeichnet that the passages from the reject at least one collection box. Intercooler, especially for a motor vehicle, characterized by the features of one of the preceding Claims. Method for producing a tube plate, characterized through the process steps a) Provide a level sheet, b) Setting up one or more edge regions of the plane Sheet metal by means of a forming process, c) introduction of contiguous Recesses in the sheet by means of a forming process, wherein the wells each have a substantially planar base and one the base area have encompassing and circumferential flank, d) piercing the base areas by means of a pull-through method and in particular e) coining of Insertion bevels for Facilitation of an introduction of pipes in the passages created in step d).