BRPI0414439B1 - HEAT EXCHANGE PROCESS FOR MANUFACTURING A TUBULAR BACKGROUND OF A HEAT EXCHANGE - Google Patents

Abstract

"heat transmitter". tube heat transmitter and at least one collecting box (20), the collecting box comprising at least one tubular bottom (30) with passages (70), and the passages (70) are hugged by flanks (91-94 ).

Description

(54) Title: HEAT EXCHANGER PROCESS FOR MANUFACTURING A HEAT EXCHANGER TUBULAR BACK (51) Int.CI .: F28F 9/02; F28F 9/18; F28D 1/053 (30) Unionist Priority: 17/09/2003 DE 103 43 239.6 (73) Holder (s): MAHLE BEHR GMBH & CO. KG (72) Inventor (s): KARSTEN EMRICH; WERNER HELMS; MARKUS RECK; STEFAN WEISE

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DESCRIPTION REPORT OF THE INVENTION PATENT FOR HEAT EXCHANGER PROCESS FOR MANUFACTURING A TUBULAR BACKGROUND OF A HEAT EXCHANGER.

[001] The present invention relates to a heat exchanger, especially a supply air cooler for a motor vehicle.

[002] To obtain an increase in the power of an internal combustion engine, the air to be added to the combustion can for example be compressed with a turbocharger, before being added to the combustion chambers of the internal combustion engine. Compression of air, however, simultaneously causes heating of the air, which is disadvantageous for an optimal course of the internal combustion process. For example, an early ignition or a high emission of nitrogen oxide can thus be triggered. In order to avoid the disadvantageous consequences of superheated air added to internal combustion, after a turbocharger, a heat exchanger, connected as a supply air cooler, is connected, with which the compressed air can be cooled to an allowable temperature before combustion.

[003] A supply air cooler is described, for example, in German patent DE 197 57 034 A1. In the heat exchanger there, the hot air is introduced into a first collector channel of the heat exchanger, where it is distributed and flows in current into flat tubes, which flow into the collector channel. The flat tubes are arranged side by side and parallel to each other with the side faces containing the long sides of their cross section and form a flow path, through which the cooling air is conducted. In the flow path, between the flat tubes there are cooling ribs, which produce an efficient heat exchange between the flat tubes and the cooling air stream. After crossing the cooling air stream, the flat tubes of Petition 870170031834, of 5/15/2017, p. 9/23

2/9 smack in a second collecting channel, which supplies the supply air entering, cooled, compressed to combustion in the engine.

[004] In heat exchangers such as such supply air coolers, the tubes are usually inserted into openings in a tubular bottom and fluid-tight welded. With each compressed air supply, this weld joint is subjected to high mechanical stresses due to rapid pressure changes. In particular, the narrow sides of flat tubes do not meet the increasing strength requirements, which may result in a lack of tightness especially in regions of such tube-bottom joints facing the sides of the tubular bottom.

[005] A simple way to increase the resistance of tube-bottom joints is to use tubes and / or tubular bottoms with greater wall thickness or external and / or internal ribs with greater material thickness. The greatest mechanical stability is clear in both cases; but the largest expense in material costs and weight required is very high.

[006] Other proposals for solutions are concerned with reducing the mechanical stress of tube-bottom joints by using traction anchors in the supply air boxes. These traction anchors stabilize the supply air boxes and thus relieve the tube-bottom joints, but lead to an increase in material expenditure and pressure loss caused by the supply air cooler.

[007] The purpose of the invention is to provide a heat exchanger, especially a supply air cooler, in which the mechanical demands of tube-bottom joints are reduced without further expenditure of material.

[008] According to the invention, a heat exchanger has tubes that are suitable to be crossed in current by a first step 870170031834, from 05/15/2017, p. 10/23

3/9 ro the middle and surrounded by current by a second medium, so that heat is transmissible from the first to the second medium or inversely. At least one collector box communicating with the tubes comprises at least one tubular bottom, the tubular bottom being essentially flat and having passages, in which the tubes are inserted to form the communicating union with the collector box.

[009] The basic idea of the invention is to geometrically configure the regions of the tubular bottom in such a way as to involve the passages in the form of recesses or elevations that the passages are respectively arranged at the base of a recess or at the top of an elevation. As a result, the passages are surrounded by flanks, namely, the flanks of the recesses or elevations. Thanks to such a geometric shape, especially due to the surrounding configuration of the flanks, the flexural strength of the tubular bottom is high in relation to a flat tubular bottom in many directions, so that deformations that occur due to a pressure request from the collecting box are reduced , tube joints being mechanically relieved with the tubular bottom. Preferably, the recesses or elevations are of such a width that the flanks respectively of two neighboring passages are contiguous forming a reinforcing groove.

[0010] Thanks to the configuration according to the invention of the heat exchanger, its mechanical strength and thus also its service life are increased, without requiring a greater expenditure of material or number of parts.

[0011] According to a preferred configuration, the flanks have an essentially constant width at the periphery of a passage. The flexural strength of the tubular bottom in all directions is thus increased in an essentially uniform manner. [0012] According to an advantageous form of execution, the tubes are

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4/9 executed as flat tubes and arranged in one or several rows. The passages as well as the intermediate grooves formed by the flanks are then configured lengthwise in correspondence to the tubular cross sections.

[0013] Preferably the flanks have a rounding with approximately constant radius of curvature or several roundings with different radii of curvature respectively. This results in an especially good approximation to a semicircular cross section of the grooves located between the passages, resulting in a particularly high flexural strength.

[0014] According to another form of implementation, the flanks cover one or more flat regions respectively, so that the flanks or grooves have a faceted shape between the passages. This enables safe manufacturing with low manufacturing tolerances.

[0015] Especially preferably, at least one flat region forms an obtuse angle with the respective passage. This means that the passage itself produces an additional increase in the flexural resistance of the tubular bottom, since the passage in the same direction presents the recess or elevation at whose base or on the summit of the passage.

[0016] The angle between the flat region of the flank and the passage is preferably between 30 ^o and 60 ^o , especially preferably about 45 ^o . In that case, the width of the flank, under certain circumstances, is approximately equal to a height of the flank, so that a particularly high stability of the tubular bottom with respect to deformations results.

[0017] According to an advantageous configuration, the passages point out of at least one collection box. This eventually has the advantage that respectively a region of the adjacent flanks 870170031834, dated 05/15/2017, p. 12/23

5/9 water to an edge of the tubular bottom transitions to an edge of the tubular bottom under certain vertical circumstances, resulting in a greater increase in resistance of the tubular bottom.

[0018] According to another preferred configuration, the heat exchanger according to the invention is made as a supply air cooler, which is particularly suitable for use in motor vehicles. In particular, the supply air cooler features two collection boxes, one of which is intended for distribution and a second for collecting supply air. Advantageously, each of the collection boxes has precisely a tubular bottom, which is provided with a series of tubular openings. It is also advantageous to employ a row of flat tubes with intermediate corrugated ribs, especially welded, as this results in an increased heat transmission area. As a refrigerant medium, air is preferably used, and other refrigerant media, such as water or refrigerant, are also viable.

[0019] According to an advantageous embodiment of the invention, a tubular bottom is manufactured, in that, by means of a deformation process, one or more edge regions of a flat plate are raised and reciprocally recessed into the plate. The recesses then have an essentially flat base area and a circulating flank, respectively, embracing the base area. Then, the base areas of the recesses are drilled with the aid of a drilling process forming passages. Should tubes be threaded through the recesses side in the tubular bottom, in particular, insertion chamfers are formed to facilitate such insertion of tubes in the passages.

[0020] In terms of manufacturing technique, it is advantageous to configure a tubular bottom with one or more rows of

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6/9 flanks and / or equal passages.

[0021] The invention will be explained below with the aid of execution examples with reference to the drawings. Show:

Figure 1 - an oblique view of a tubular bottom,

Figure 2 - a side view of a tubular bottom with an inserted tube,

Figure 3 - a longitudinal section through a tubular bottom with inserted tubes,

Figure 4 - a longitudinal section through a tubular bottom cutout with inserted tube and

Figure 5 - a longitudinal section through a tubular bottom cutout with inserted tube.

[0022] Figure 1 shows a cutout of a heat exchanger 10 in a perspective representation. A collection box 20 for dispensing a first medium consists of a tubular bottom 30 and a box cover not shown, which are welded together in a common contact area 50. The box cover is inserted therein in the tubular bottom 30. It is also conceivable to rest the box cover on the tubular bottom 30 or to arrange it in another way on the tubular bottom 30. In other examples not shown, a tubular bottom and a housing cover are joined together by welding, gluing or by locking due to the shape, namely formed in one piece or a single part, that is, for example, of a molded plate.

[0023] The tubular bottom 30 has a tubular opening 60, the edge of which is molded as so-called passage out of the collection box. An essentially rectangular flat tube is insertable in the tubular opening 60 and weldable or can be joined by brazing with the tubular bottom 30. There are no corrugated ribs, which on both sides are contiguous to the flat tube also not shown and welded with the latter , so that a

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7/9 transmission of heat from a medium flowing through the tube to a medium flowing around the tube and the ribs, or vice versa. In total, the heat exchanger 10 comprises a whole row of corrugated ribs and alternating flat tubes, which form a so-called block of rib-tubes.

[0024] As the collector box 20 is activated with a medium under pressure, the collector box 20 under certain circumstances deforms in such a way that its cross-sectional shape approaches a circular shape. To cope with such a deformation, the passage 70 is embraced by a surrounding flank 90, which connects to the passage at an obtuse angle. The flank has a width that is essentially constant around the passage 70. This results in a uniform recess of the tubular bottom 30 both in the longitudinal direction of the tubular bottom through the flank regions 91, 92 on the front sides of the passage 70 as well as in the transverse direction of the tubular bottom by the flank regions 93, 94 on the longitudinal sides of the passage 70.

[0025] This results in less deformation of the tubular bottom 30 under pressure from the collecting box 20. This reduced deformation of the tubular bottom 30 causes a decrease in the mechanical stress of the tube or the tube-bottom joint. In particular, the front sides of the flat tube are mechanically as much as required when such pressure-conditioned deformations are thus relieved. [0026] As can be seen in the side view of the heat exchanger 110 in Figure 2, the tube 120 is inserted in such a measure in the tubular opening 160 that a region of the upper edge 121 of the tube 120 protrudes beyond the tubular bottom 130. It is thus ensuring a good use of an internal area of the passage 170 not visible, facing the tube 120, as the back area for the tube-bottom connection. This serves, for example, as a sealed weld. In order to avoid a drop in DisPetition 870170031834, dated 05/15/2017, p. 15/23

8/9 necessarily high pressure of the first medium through the heat exchanger, the overflow of the tube 120 beyond the tubular bottom 130 is kept as small as possible. For this reason, the tubular opening 160 is located in a central region 131 essentially flat of the tubular bottom 130.

[0027] Passage 170 is embraced by a flank 190, whose front sides 191, 192 show transition, on one side, under an obtuse angle, to passage 170 and, on the other side, also under an obtuse angle, for a region vertical edge 132 of the tubular bottom 130. Thanks to the cross section of the tubular bottom 130 in a s-shape, thus joined, in the region of the cap connection area 150 - edge region 132 - flank region 191/192 - passage 170, tube 120 or the tube-bottom joint is assigned an additional strain reduction. [0028] Figure 3 shows another example of execution of a heat exchanger 210 in cut in a longitudinal section. Tubes 220,

221, 222 are inserted in passages 270, 271, 272 of a tubular bottom 230. To reduce a pressure drop in a medium flowing through the heat exchanger 210 and even through tubes 220, 221,

222, passages 270, 271, 271 protrude from the collection box not shown and tubes 220, 221, 222 do not protrude through the tubular bottom or through their passages 270, 271, 272.

[0029] The passages 270, 271, 272 are then embraced by flanks 290, which have respectively a partial region 295 flat. The flat partial region 295 forms an obtuse angle with the passage 270, with which the strut effect of the recess formed by the flank 290 on the tubular bottom 230 is further reinforced. The flanks 290 are then directly contiguous, so that the grooves are formed 299 , which can be seen in Figure 3 in its cross section. As clearly shown in this cross section, the grooves 299 do not have horizontal regions, located between the flanPetition 870170031834, of 05/15/2017, p. 16/23

9/9 cos 290.

[0030] Advantageously, the width b is similar to the height h of the flanks 290, especially preferably almost the same. For this reason, the angle between the partial region 295 flat sidewall 290 and the passage 270 matter in about 45. This results for the cannula bandages 299 at a angle of about 90 ^o , which is associated with a particularly high reinforcement effect of the cannula bandages 299.

[0031] Figure 4 shows the cutout of a modified configuration of the heat exchanger of Figure 3. Here the tube 320 protrudes through passage 370, but ends below a surface 335 of the tubular bottom 330. This results in a high security of manufacture with respect to a fluid-tight joint between the tubular bottom 330 and the tube 320. For example, a welded joint is enhanced by a weld slit 376 added in addition to weld slit 375. The weld slit then simultaneously serves as a chamfer of introduction to facilitate the insertion of the tube 320 in the tubular bottom 330.

[0032] In opposition to this, in the execution example shown in Figure 5, the tube 420 protrudes through the passage 470 and through a surface 435 of the tubular bottom 430. Due to the greater tolerances associated with this with regard to the length of the tube 420, a further increase in manufacturing safety follows.

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Claims (9)

1. Heat exchanger (10; 110; 210) with tubes (120; 220; 320; 420) and at least one collection box (20), with the collection box (20) covering at least one tubular bottom (30; 130; 230; 330), and the tubular bottom (30; 130; 230; 330) has passages (70; 170; 270; 370; 470), where the tubes (120; 220; 320; 420) are inserted, characterized by the fact that the passages (70; 170; 270; 370, 470) are surrounded by a surrounding flank (90; 190; 290) respectively, with the surrounding flanks (90; 190; 290) being two passages (70 ; 170; 270; 370, 470) neighbors are mutually contiguous forming a groove (299). 2. Heat exchanger according to claim 1, characterized by the fact that the surrounding flanks (90; 190; 290) have an essentially constant width at the periphery of a passage (70; 170; 270; 370; 470). Heat exchanger according to claim 1 or 2, characterized in that the tubes (120; 220; 320; 420) are flat tubes arranged in at least one row, the passages (70; 170; 270; 370; 470) are executed longitudinally in correspondence to the cross sections of pipe (120; 220; 320; 420) and the flanks (90; 190; 290) of the passages (70; 170; 270; 370; 470) are mutually contiguous forming longitudinal grooves (299). Heat exchanger according to one of claims 1 to 3, characterized in that the sides (290) are rounded with an approximately constant radius of curvature respectively. 5. Heat exchanger according to claim 4, characterized by the fact that the flanks (290) have various roundings with different radii of curvature respectively. Petition 870170031834, of 5/15/2017, p. 18/23 2/2 Heat exchanger according to one of claims 1 to 5, characterized in that the flanks (290) have at least one flat region (295) respectively. 7. Heat exchanger according to claim 6, characterized by the fact that at least one flat region (295) forms an obtuse angle with the respective passage (270), especially an angle between 30 ^o and 60 ^o . Heat exchanger according to one of claims 1 to 7, characterized in that the passages (70; 170; 270; 370; 470) protrude from at least one collecting box (20). 9. Process for manufacturing a tubular bottom (30; 130; 230; 330) of a heat exchanger, as defined in any one of claims 1 to 8, characterized by the steps of, a) provision of a flat plate, b) assembly of one or more edge regions of the flat plate by means of a deformation process, c) introduction of mutually contiguous recesses in the plate by means of a deformation process, the recesses having respectively an essentially flat base area and a surrounding flank and embracing the base area, d) drilling of the base areas through a drilling process and especially, e) stamping of insertion chamfers to facilitate the introduction of tubes (120; 220; 320; 420) in the passages (70; 170; 270; 370, 470) produced in step d). Petition 870170031834, of 5/15/2017, p. 19/23 ·· »« · · 1/2