KR20100106434A - Extruded tube for a heat exchanger - Google Patents

Abstract

The present invention relates to an extruded tube for a heat exchanger, wherein the extruded tube for a heat exchanger comprises at least two outer side walls (1, 2) which are generally parallel. The outer sidewalls 1, 2 extend in the longitudinal direction (z) and the transverse direction (y) of the extruded tube, and two outer narrow sides in the vertical direction (x) of the extruded tube. sides: connected by 3 and 4). At least one continuous web 5 between the outer sidewalls 1, 2 extends in the longitudinal z and vertical x directions of at least two ducts of the extruded tube ( Divide 6). At least one of the outer sidewalls 1, 2 has embossings 7, the embossings 7 being fed into the ducts 6 of the outer sidewalls 1, 2. To form both bulged portions 7 and convex portions 7 (substantially extending in the transverse direction y) of the continuous web 5. The convex portions 7 of the at least one continuous web 5 have a controlled orientation with respect to the transverse direction y.

Description

Extruded Tube for Heat Exchanger {EXTRUDED TUBE FOR A HEAT EXCHANGER}

The present invention relates to an extruded tube for a heat exchanger, a heat exchanger having the extruded tube, and a method for producing the extruded tube.

U.S. Patent No. 3,596,495 A discloses tubes for heat exchangers that can be manufactured by extrusion and drawing, in which several chambers according to a representative embodiment are divided by internal webs. do. In addition, the chambers are deformed by a depression introduced externally to both the region of the sidewalls and the region of the webs, in order to generate turbulences for the fluid flowing therethrough.

It is an object of the present invention to provide an extruded tube for a heat exchanger in which a particularly large heat transfer can be achieved with proportionally low pressure losses throughout the extruded tube.

The above object is achieved by an extrusion tube of the present invention having the features of claim 1 of the claims. The formation of a specific channel shape of the extruded tube can be achieved by controlled orientation of the bulges in the web in the vertical as well as transverse directions. On the other hand, according to the prior art described above, uncontrolled narrowing of the channels by bulging the web arbitrarily with respect to the direction is possible in the transverse direction.

In a preferred embodiment of the invention, at least one of the channels of the longitudinally formed extrusion tube has a regular wave-shaped course with respect to the transverse direction. In this way, turbulences and heat transfer on the one hand are increased, and on the other hand it is possible to avoid narrow areas that can cause too large pressure drops and blockages due to the accumulation of substances or fluids deposited from the fluid. In this case, particularly preferably, the lateral distance between two neighboring webs is substantially constant.

In an advantageous specific design, for simple and reliable manufacture, at least one of the impressions has a long elongated shape, by which most webs are overlaid and bulged out. Particularly preferably, the impression having an elongated form has an orientation angle with respect to the transverse direction, and the bulges formed by the impression of the side walls and the webs are not located at the same height in the longitudinal direction of the tube. Aroma angles of this type are advantageously from about 0 ° to 45 °, preferably from about 20 ° to 45 °, more preferably from about 28 ° to 42 °.

In an advantageous variant, the elongated impression is arranged to have a direction parallel to the webs or to be slightly offset over or to the webs. Particularly preferably, the impression has a length of 1.1 times to 3.25 times of the channel width, preferably 1.35 times to 2.45 times and more preferably 1.62 times to 2.16 times. As a result, a force that acts uniformly on the sections and thus a significant bulging of the web is ensured, and the randomness of the material under the embossed surface due to the surface pressure due to the embossed or length-limited embossing The flow of is only localized, so that an unwanted reduction in wall thickness is reduced or avoided.

Alternatively or additionally, at least one of the impressions may be arranged to substantially overlap only at least one web. In this case, another impression does not overlap the web. In this way, the impressions bulging the sidewalls and the impressions bulging the webs can be arranged spatially separated from each other, and there can be various design options in particular for shaping the channels. The isolated impression of this type of side wall may in particular have a direction opposite to the transverse direction. The direction angle of the impressions relative to the transverse direction may advantageously be about 0 ° to 45 °, preferably about 25 ° to 45 °, more preferably about 30 ° to 40 °.

For the formation of particularly effective turbulence, at least one of the impressions can be made in the form of a winglet. In an optimized form, the winglet type impression may have a length and width ratio of 2 to 5, preferably 2.3 to 4, more preferably 2.5 to 3.2. According to an advantageous variant, the winglet type impression may have a length and width ratio of 1.2 to 5, preferably 1.5 to 3, more preferably 1.8 to 2.5.

Too long impressions can cause flat deformation of the sidewalls or cause short sidewalls to bulge out. This adversely deforms the outer size of the extrusion tube and worsens the flow of refrigerant. Likewise, during the deformation of the extruded tube in the region of the impression, buckling of the side walls and blockage or reduction of the channel cross section and thus increased pressure loss can occur.

The directions of at least some bulges of neighboring webs at substantially the same height in the longitudinal direction are generally provided in the same manner. As a result, a constant cross section of the channel is made, at least in relation to the transverse direction, for example, while being used for exhaust gas cooling, the risk of clogging by deposits is lowered. Depending on the requirements, alternatively, the direction of at least some bulges of neighboring webs at substantially the same height in the longitudinal direction may be reversed. As a result, narrow areas of the tubes can be formed in a controlled manner, which in particular can produce large turbulence. This is, for example, the risk of clogging due to sediment in the case of low or high pressure EGR coolers, refrigerant coolers, and exhaust gas coolers, for example, when conventional soot and / or hydrocarbons (HC) are discharged. This can be advantageous when it is low.

In an advantageous design, alternately providing bulging of one of the sidewalls and bulging of the web alternately in the longitudinal direction of the channel, so as to form a uniform turbulence in all spatial directions. The bulging of the web in the first direction in the transverse direction is made in the longitudinal direction of the channel in a particularly advantageous manner, then bulging one of the two side walls in the other direction, and then the remaining side wall. To bulge. In this way a screwed path of the channel is made, which advantageously causes the fluid flow to twist. Several sections described above, in particular with different twisting directions, are provided over the length of the extrusion tube.

In another advantageous embodiment, the bulging of the webs and / or the channel walls is designed to take place alternately in the opposite direction, resulting in alternating acceleration and deceleration of the flow.

In another embodiment, the channel width is reduced by the bulges because, in the longitudinal direction of the channel, the bulges of the two webs delimiting the channel are directed towards each other and have bulges lying at the same height. As a result, acceleration of the flow can be achieved in such a narrowed region. Alternatively or additionally, in the longitudinal direction of the channel, the channel width is increased by the bulges because the bulges of the two webs delimiting the channel are induced away from each other and have bulges lying at the same height. As a result, deceleration of the flow can be achieved in such a widened region. As mentioned above, in a preferred embodiment, alternating widening and narrowing of the channel may be provided.

In an advantageous design, the bulging of the web is formed by both the impression of the first side and the impression of the at least partially overlapping second side. As a result, particularly marked bulging of the web with a small bulge of the side walls can be achieved. In the case of the first variant, the bulging direction is opposite to the overlapping impressions. In the alternative or additional second variant, the bulging direction is aligned corresponding to the overlapping impressions.

In a simple implementation of the extruded tube of the present invention, the bulging of the web in a controlled direction is made by an embossing tool inclined to the side walls. In this way, during embossing, a laterally directed force is exerted on the web and the direction of bulging is predetermined. In an alternative or additional way, the bulging of the web in a controlled direction is by means of an embossing tool which acts eccentrically against the web. In particular, the embossing tool is as wide as the web in the transverse direction, the deflection of the embossing center from the center of the web is small, on the one hand, bulging the web in a controlled direction and on the other hand Allow adjacent sidewalls to bulge as little as possible in the vertical direction.

In order to be able to simply and sealably mount the inventive extrusion tube to the bottom of the heat exchanger, bulges are preferably not provided in the distal region of the extrusion tube. The distance of the tube end to the first embossing is preferably about 2 mm to 15 mm, more preferably about 4 mm to 8 mm. In another alternative embodiment, the distance from the tube end to the first embossing is preferably about 4 mm to 20 mm, more preferably about 6 mm to 12 mm.

In a preferred embodiment of the invention, the extruded tube has a bent area, so that the heat exchanger can be, for example, a U-shaped flow heat exchanger or can be generally adapted by bending the tube into a predetermined space. . To avoid excessively narrowing the channel inside the curved area, the bulges have at least reduced depth for convenience. In this case, particularly preferably, no bulges are provided in the curved area, at least in the sections.

In a preferred design, the tube material consists of a material selected from the group consisting of aluminum alloys, AlMn alloys, AlMg alloys, AlMgSi alloys. Light metal alloys as described above are particularly well extruded and shaped into the impressions of the present invention. Extruded tubes made of the aforementioned alloys have good corrosion resistance to aggressive condensate when used as an exhaust gas cooler.

In the case of the optimized shape of the extruded tube, the depth of the impressions is less than about 75%, preferably less than about 45%, more preferably less than about 30% of the tube inner diameter in the vertical direction.

Furthermore, many experiments have shown that, in the longitudinal direction, the distance between the impression on the tube bottom side and the impression on the tube top side immediately adjacent is advantageously 10 times or less, preferably 6 times or less, more preferably 6 times or less of the tube inner diameter in the vertical direction. Shows less than 3.5 times. In addition, the optimized implementation provides that, in the longitudinal direction, the distance between the impression for bulging the sidewalls and the impression for bulging the immediately next web is 8 times or less, preferably 6 times or less, of the tube inner diameter in the vertical direction, More preferably 3 times or less.

In the case of impressions which overlap several webs in the transverse direction, the optimum length of the impression in the transverse direction is about 25% to 100% of the extrusion tube width, preferably 35% to 90%, more preferably 45 % To 80%.

The transverse length of the impressions bounded between only two webs is about 25% to 130%, preferably 35% to 95%, more preferably 45% to 75% of the channel width bounded by the webs in the transverse direction. %to be.

In order to improve heat transfer, it is generally advantageous for the fin element to be arranged, in particular by material bonding, on at least one of the side walls. The material bonding can in particular be soldering. In order to ensure as even heat transfer as possible between the extrusion tubes and the fins, it is advantageous that the longitudinally repeated impression units and the repeating fin units of the fin element are not integer multiples of each other. As a result, an unsuitable regular overlap of the impression areas of the tube surface and the contact areas of the fins can be avoided.

In order to further improve heat transfer, in the inventive extrusion tube, at least one half-web may protrude from one of the side walls into one of the channels.

In an optimized embodiment, the hydraulic diameter defined as four times the ratio of the flow-through cross-sectional area to the perimeter that can be wetted by the first fluid is provided in the range of 1.2 mm to 6 mm. .

The preferred range of the hydraulic diameter is about 2 mm to 5 mm, preferably 3.0 mm to 3.4 mm, more preferably 3.1 mm to 3.3 mm, especially about 3.2 mm.

In general and in particular for the structural design of high pressure heat exchangers, it has been found that the hydraulic diameter d _h is preferably about 2 mm to 3.5 mm, more preferably 2.5 mm to 3.5 mm.

The ratio of the hydraulic diameter d _h to the channel cover thickness s for optimizing the weight and amount of material is advantageously in the range of 0.8 to 8, preferably 1.2 to 6, more preferably 1.4 to 6 to be. For the same reason, the ratio of the web thickness d and the channel cover thickness s is preferably less than 1.0.

Generally preferably, the ratio between the perimeter of the extruded tube and the perimeter that can be wetted by the first fluid is in the range of 0.1 to 0.9, in particular 0.1 to 0.5, the latter being particularly suitable for exhaust gas coolers.

In an optimized structural design, the ratio of the distance e between the two webs, in particular the facing webs and / or the offset webs offset to each other, to the height b of the tube cross section is 0.8 or less, in particular 0.3 to 0.7. In range The ratio of the distance a3 of the first partial web to the whole web to the distance a4 of the second partial web to the whole web having a suitable structural design is preferably in the range of 0.5 to 1.0, more preferably 0.6 to 0.8. Mine

In general, in order to increase the service life, in particular where corrosive fluids such as, for example, exhaust gases are involved, the at least one web and / or channel cover, preferably the inner side of the channel cover is preferably zinc coated and And / or a corrosion protection film in the form of a zinc coating.

Depending on the requirements, the cross section of the extruded tube can preferably be formed, for example, rectangular, oval or semi-elliptical.

In a particularly suitable structural design of the extruded tube for use in a heat exchanger, 2 to 20, preferably 5 to 15, more preferably 7 to 12, particularly preferably 8 to 11, in particular 9 webs Arranged adjacent to each other across the tube cross section.

The object of the invention is also achieved by a heat exchanger having an extruded tube of the invention, according to claim 50. In this regard, a first fluid that exchanges heat with fluid flowing outside the tube circumference is carried into the extrusion tube. Heat exchangers as described above are particularly widely used in motor vehicles, and because of their high weight and space requirements, optimization of heat exchanger performance by the impressions of the present invention is particularly advantageous.

In a preferred embodiment, air flows around the extrusion tube. In an alternative embodiment, for example in the case of an indirect exhaust gas cooler of an automobile, cooling fluid may flow around the extrusion tube.

The heat exchanger of the present invention may be an exhaust gas cooler for cooling the exhaust gas stream recycled, but may also be an intercooler, oil cooler or refrigerant cooler of the engine. Such heat exchangers are particularly preferably used in motor vehicles.

The object of the invention for the process for producing the extruded tube is achieved by the features of claim 57 of the claims. For convenience, the extrusion profiles are first shaped by a known extrusion process according to the type of base body, which is generally columnar, and then the impressions are introduced. This is done on a cooled and / or temporarily stored profile strip, in a step immediately after extrusion or in a separate step, especially in the case of still warm profiles.

In a preferred design, the impression is made by an embossing roller. Alternatively or additionally, however, it may also be made by a press die.

In a preferred embodiment, after the impression, the step of separating the extruded tube from an endless or quasi-endless profile strip is provided to optimize the manufacturing cost. This can be done, for example, by a sawing process. In a particularly preferred design, the separation is done by a pre-drawing and tearing off line. In this case, a large amount of chips can be avoided during the separation process.

According to a preferred embodiment of the invention, the directions of at least some bulges of neighboring webs that are substantially the same height in the longitudinal direction are opposite to each other. Preferably, in the longitudinal direction of the channel, one of the side walls is bulged alternately and the web is bulged alternately. Preferably the bulging of the web in the first direction in the transverse direction is made in the longitudinal direction of the channel, then bulging one of the two side walls in the other direction, and then bulging the remaining side walls. To come out. Preferably, in the longitudinal direction of the channel, the channel width is reduced by the bulges because the bulges of the two webs delimiting the channel are directed towards each other and have bulges lying at the same height. The channel width is increased by the bulges, preferably in the longitudinal direction of the channel, because the bulges of the two webs delimiting the channel are induced away from each other and have bulges lying at the same height. Preferably the bulging of the web is formed by both the impression of the first side and the impression of the second side at least partially overlapping. Preferably the bulging direction is opposite or the same direction as the overlapping impressions.

According to a preferred embodiment of the invention, the bulging of the web in a controlled direction is by means of an embossing tool inclined to the side walls. The bulging of the web in a preferably controlled direction is by means of an embossing tool which acts eccentrically against the web. Preferably no bulges are provided in the distal region of the extrusion tube. Preferably the distance of the tube end to the first embossing is about 2 mm to 15 mm, in particular about 4 mm to 8 mm.

According to a preferred embodiment of the present invention, the extruded tube has a curved area, in which the bulges have at least reduced depth. In this case, no bulges are provided in the curved area, at least in the sections. Preferably the material of the tube is made of a material selected from the group consisting of aluminum alloys, AlMn alloys, AlMg alloys, AlMgSi alloys. Preferably the depth of the impressions is less than about 75%, preferably less than about 45%, more preferably less than about 30% of the tube inner diameter in the vertical direction. Preferably, in the longitudinal direction, the distance between the impression of one side wall and the impression immediately next to the other side wall is 10 times or less, preferably 6 times or less, more preferably 3.5 times or less of the tube inner diameter in the vertical direction. Preferably, in the longitudinal direction, the distance between the impression for bulging the side wall and the immediate impression for bulging the web is 8 times or less, preferably 6 times or less, more preferably 3 times of the tube inner diameter in the vertical direction. It is as follows. Preferably the length of the impression overlapping several webs in the transverse direction is about 25% to 100% of the extrusion tube width, preferably 35% to 90%, more preferably 45% to 80%. Preferably the length of the impression arranged transversely between the two webs is about 25% to 130%, preferably 35% to 95%, more preferably 45% to 75% of the channel width bounded by the webs. to be.

According to a preferred embodiment of the present invention, at least one of the side walls is arranged with a fin element, in particular by material bonding. Preferably the longitudinally repeated impression units and the repeating pin units of the pin element are not integer multiples of each other. Preferably at least one half-web protrudes from one of the side walls into one of the channels.

According to a preferred embodiment of the present invention, the hydraulic diameter defined as four times the ratio of the flow-through cross-sectional area to the perimeter that can be wetted by the first fluid is in the range of 1.2 mm to 6 mm. to be. Preferably the hydraulic diameter is about 2 mm to 5 mm, preferably 3.0 mm to 3.4 mm, more preferably 3.1 mm to 3.3 mm, in particular about 3.2 mm. Preferably the hydraulic diameter is, in particular for high pressure heat exchangers, about 2.5 mm to 4 mm, in particular 2.8 mm to 3.8 mm. Preferably the hydraulic diameter is, in particular for low pressure heat exchangers, about 2 mm to 3.5 mm, in particular 2.5 mm to 3.5 mm. Preferably the ratio of the hydraulic diameter and channel cover thickness is in the range of 0.8-9, preferably 1.2-6, more preferably 1.4-6. Preferably the ratio of web thickness and channel cover thickness is less than 1.0. Preferably the ratio of the outer periphery of the extruded tube and the circumference that can be wetted by the first fluid is in the range of 0.1 to 0.9, in particular 0.1 to 0.5. Preferably the ratio of the distance between the two webs, in particular the opposing partial webs and / or the partial webs offset from each other, to the height of the tube cross section is below 0.8, in particular in the range of 0.3 to 0.7. Preferably the ratio of the distance of the first partial web to the entire web to the distance of the second partial web to the entire web is preferably in the range of 0.5 to 1.0, in particular 0.6 to 0.8.

According to a preferred embodiment of the invention, the at least one web and / or channel cover, preferably the inner side of the channel cover, has a corrosion protection film, preferably in the form of a zinc coating and / or zinc coating. Preferably the cross section of the extruded tube is formed in a rectangular, elliptical or semi-elliptic shape. Preferably 2-20, preferably 5-15, more preferably 7-12, particularly preferably 8-11, in particular 9 webs are arranged next to each other across the tube cross section.

According to a preferred embodiment of the invention, air flows around the extruded tube of the heat exchanger. Preferably a cooling fluid flows around the extrusion tube. Preferably the heat exchanger is an exhaust gas cooler, an engine intercooler, an oil cooler or a refrigerant cooler for cooling the exhaust gas stream being recycled.

According to a preferred embodiment of the process for producing the extruded tube of the invention, the impression is made by an embossing roller. Preferably the impression is made by a press die. Preferably after the impression, a step of separating the extruded tube from an endless or quasi-endless profile string is provided. Preferably the separation is by a sawing process or in particular by a pre-drawing and tearing off line.

According to the extruded tube for the heat exchanger according to the invention, on the one hand it is possible to form an effective turbulent flow of the cooling fluid, thereby increasing the heat transfer, on the other hand too large pressure drop and accumulation of precipitated substances or fluids from the fluid. The risk of blockages can be avoided.

Other advantages and features of the present invention will become more apparent from the following detailed description of embodiments and claims.

1 shows a schematic of an extrusion tube for the definition of each spatial coordinate.
Figure 2 shows a first embodiment of an extrusion tube according to the invention with a total of nine variants from 2.1 to 2.9.
3 shows embossing processes for producing the extruded tube according to FIG. 2.
4 shows a perspective view of an extrusion tube according to a first embodiment.
FIG. 5 shows a detailed view of the extrusion tube shown in FIG. 4.
Figure 6 shows a second embodiment of an extrusion tube according to the invention with a total of ten variants from 6.1 to 6.10.
6a shows further modifications 6.11 to 6.15 of the second embodiment.
7 shows a perspective view of two embossing rollers for the production of an extruded tube according to the invention.
8 illustrates a preferred choice of hydraulic diameter for the ratio of perimeter wettable by the first fluid and the outer perimeter of the extruded tube.
9A and 9B show two variants of a preferred embodiment of a cross section of an extruded tube with an extruded channel cover and webs extruded into the channel cover.
10A and 10B show two variations of another embodiment with partial webs, as shown in FIGS. 9A and 9B.
11A and 11B show two variations of another embodiment with partial webs, as shown in FIGS. 9A and 9B.
12 shows another embodiment of a cross section of an extruded tube with partial webs.
13 shows another embodiment of a cross section of an extruded tube with partial webs.

1, the present invention relates to an extrusion tube extending in the longitudinal direction z. The extruded tube has a longitudinal extension transverse to the longitudinal direction, thereby forming in particular a flat tube. The transverse direction in claim 1 points in the y direction of FIG. 1, wherein the (long) side walls 1, 2 of the extrusion tube extend substantially in this direction. The vertical direction refers to the x direction of FIG. 1 and extends perpendicularly to the longitudinal and transverse directions. The side walls 1, 2 do not necessarily have to extend straight in cross section, but may be curved, but in this sense have a direction that is "substantially" transversely or "at least nearly parallel".

The side walls 1 and 2 are connected to each other via shorter, narrower narrow sides 3 and 4 extending substantially vertically to form a closed flat tube.

The sidewalls are connected via at least one web inside the flat tube, and in the exemplary embodiments shown, each of several types of continuous webs (5, 79, 89) are mediated. Individual channels 6 are formed which are divided into each other. Apart from these continuous webs or full webs (5, 79, 89), partial webs (5 ', 79', 89 ') (see, eg, FIG. 4 or FIGS. 10A-11B). It may alternatively be provided in such a way as to project into the channels 6, such as a pin, to increase the contact area between the channel wall and the fluid.

In order to optimize the turbulence of the flowing fluid, impressions 7 are provided in the extruded tube, the impressions 7 forming local bulges which are proportional to the longitudinal direction. It protrudes into the channels 6 and affects the fluid flow. Here, the bulges indicate vertically projecting bulges in the sidewalls 1, 2 or bulges or bucklings in which the continuous webs 5, 79, 89 protrude transversely. Can point to The bulges of the webs as described above are achieved in that the impression coincides with the area of attachment of the web to the side wall.

The protruding direction of the web is predetermined in the transverse direction in a controlled manner by appropriate measurements, and not arbitrarily or randomly. To this end, two different approaches are taken in the manufacture of the impressions:

On the one hand, the press die 8 (see FIG. 3) or the embossing roller 9 ′ (see FIG. 7) has inclined embossing edges 8a, 10 ′. 3A shows a simple embossing of the extruded tube by a smooth, non-sloped embossed edge that overlaps most of the extruded tube in the transverse direction, whereby the webs 5 are left or right in the drawing in an unregulated manner. Bulging out toward you. In contrast, in the case of B of FIG. 3, the embossed edge has a slight angle of inclination α, which is generally less than 10 ° with respect to the side surface 1. As a result, in the case of B of FIG. 3 described above, since the forces exerted in the embossing process act asymmetrically on the attachment area of the web, all the webs 5 bulge out toward the right in the drawing in a controlled manner. .

On the other hand, control of the bulging direction can also be made for punctiform impressions. To this end, in the case of FIG. 3C, toothed embossing edges 8b act on the extruded tube in small local protrusions or in a point-like manner. As such, the action of the points is substantially localized slightly above the webs 5. As a result, the buckling of the webs 5 takes place in a predetermined direction relative to the transverse direction. Also in FIG. 3C described above, since the embossing points act somewhat to the left of the center of the webs 5, the buckling direction of the webs 5 also becomes right.

An alternative option of adding substantially pointed embossing with local protrusions to the press die 8 is given by an embossing roller 9 with pointed local protrusions 10 shown in FIG. 7. Alternatively, the embossing roller 9 ′ also shown in FIG. 7 has elongated protrusions 10 ′ extending at least over the entire width of the channel or substantially over the entire width of the extrusion profile. . For example, an embodiment such as that shown in FIG. 4 may be made of a roller 9 'of the type described above, and embodiments such as that shown in FIGS. 6 and 6A may be used in the case of the embossing roller 9 described above. It can be made up of local protrusions. In principle, the two types of protrusions 10, 10 'described above can be provided together in the same embossing roller.

The first embodiment according to FIG. 2 and the second embodiment according to FIG. 6 with some variations are shown substantially in this type. The first embodiment according to FIG. 2 processes the first type of impressions with smooth and inclined embossed edges which simultaneously overlap one or more webs 5 of the extrusion tube and simultaneously press the sidewalls inwardly between the webs. For convenience, the respective embossed edges or impressions are arranged in a direction of an angle with respect to the transverse direction. As a result, the bulges of neighboring webs, caused by the same impression, are offset from each other in the longitudinal direction such that in a simple manner the wave-shaped modulation of the channels 6 is mostly transversely constant. The wall is made of streets. The angle of orientation of the aforementioned type in a typical embodiment is about 35 ° and is shown in the embodiments of 2.3 to 2.9 of FIG. 2. Since the unfavorable overlapping of the fins with the impressions resulting in areas of poor heat removal is avoided, the aforementioned impressions having an angular direction with respect to the transverse direction are in particular a cooling fin (not shown) which is soldered to the extrusion tube. Very suitable for combination with

In general, in 2.1-2.9 of Fig. 2, the topmost impressions are shown in solid lines, and the bottom surface impressions which are not visible in plan view are shown in dashed lines. The controlled projecting direction of the webs is depicted in each case by arrows shown inside the impressions.

The impressions are made on both sides 1, 2 for convenience. Such opposite impressions are arranged to overlap (eg, as in the embodiments of 2.2 and 2.4 of FIG. 2) or to be offset in a crosswise manner (eg, as in the embodiments of 2.1 and 2.3 of FIG. 2). Can be. The direction angles of the impressions may vary and may intersect, in particular, as in the embodiment of 2.5, 2.8 and 2.9 of FIG. For example, as in the embodiments of 2.6 to 2.9 of FIG. 2, several impressions may be provided having various direction angles and shorter than the width of the extrusion tube in the transverse direction.

In the case of some of the foregoing embodiments, for example 2.1, 2.3 or 2.7 of FIG. 2, in order to achieve the largest turbulence generation possible with a moderate increase in pressure loss, The protruding direction is opposite to those of the lower impressions which are alternately arranged in the longitudinal direction.

In the case of the second embodiment according to FIG. 6, there are many second types of local impressions. Unlike the first embodiment according to FIG. 2, the embossing is not made over the entire tube width, but only locally limited. In this case, there is an advantage that the buckling of the tube webs and the contraction of the channel height in the vertical direction alternate with each other. Thus, it is possible to have additional design flexibility which is particularly useful in view of the generation of rotational flow in the channels. In this way, even more complicated three-dimensional swirling and flow conditions can be created than in the first embodiment described above.

Preferably, the impressions are alternately made longitudinally in the form of embossing of the tube wall after embossing of the tube webs, followed by embossing of the tube webs again. The embossings are also made alternately on the sidewalls 1, 2, in particular in the longitudinal direction on the lower sidewall 2 after buckling of the web 5 by the impression 7 in one direction on the upper sidewall 1. ), Buckling of the web (5) by the impression (7) in a different orientation direction on the lower side wall (2). After that, the embossing of the webs by buckling of the web 5 using the impression on the upper side wall 1 and the like in the first direction is repeated cyclically. However, other combinations and arrangements of impressions in the flow direction, such as the embodiments of 6.1 to 6.17 shown in FIGS. 6 and 6A, may also be envisioned. In the figures, the impressions bulging out due to the spatial overlapping of the web 5 have a directional arrow. Deviations from the center point are not shown in the drawings for clarity. Basically, only a small control deviation of the press die from the center point on the web 5 is necessary to predetermine the direction of projection of the web.

The webs may bulge on both sides from the top and bottom side, such as in the 6.11 to 6.13 embodiments of FIG. 6A, to be able to achieve the most uniform protrusion possible. In this case, the impressions of the side walls acting on the webs in each case at least partially overlap, and the web bulges out largely at the same location from both side walls. The protruding directions of the overlapping impressions may be in the same direction (see, for example, embodiments 6.11 and 6.13 of FIG. 6A) or in opposite directions (see embodiment 6.12 of FIG. 6A).

Embossing of the tube webs and tube walls, on the one hand, leads to a reduction in the hydraulic diameter, which increases tube performance with respect to heat transfer, while on the other hand, directed flow deflection in both the yz and xz planes. deflection).

6 shows advantageous impressions through the embodiment where there are three intermediate webs 5 in the tube. In each case, the impression of the upper side wall 1 is shown in solid lines and the impression of the lower side wall 2 is shown in dashed lines. The direction of web buckling is indicated by arrows. Depending on the requirements, the impressions in the x, y, z directions can be made in a circular, elliptical, long oval, rectangular or other form. The impressions may be made alternately as described above. The deformation of the channel tube wall can be effected by one or two embossings in the same position for each channel (see embodiments 6.4, 6.5, 6.9, 6.10 of FIG. 6). However, in special cases, especially for very wide channels, the above-described modification may be made by two or more impressions in the same position.

In the case of the 6.3 embodiment of FIG. 6, the impressions of the side walls 1, 2 are seen between the webs 5 and are oriented at a defined direction angle with respect to the transverse direction. In this embodiment the direction angle of the impression with respect to either the z or y axis is about 30 ° to 40 °. In addition to the modifications described above, any other combinations between the deflection direction and the impression sequence are also conceivable.

The 6.4, 6.5, 6.9, 6.10 embodiments of FIG. 6 show a variant with winglet-like, ie angular, elongated impressions with respect to each other between the webs 5. Depending on the requirements, other combinations of winglets are conceivable, in addition to the orientations of the webs as well as the embodiments described above in relation to their position and orientation with respect to each other. In the case of impressions in the form of winglets, the direction angle of the impression relative to either the z-axis or the y-axis is preferably about 28 ° to 42 °.

Furthermore, in addition to the above-described variants, in particular in the case of very wide channels, it may be provided to impress one or more winglets for each channel in the transverse direction.

The shape of the winglet may be chosen such that the ratio of length to width is in particular about 1.8 to 2.5 times or 2.5 to 3.2 times.

In the case of winglet-shaped impressions between the webs 5, since the flow flows in the induced direction with a much larger vortex through the flow guidance of the type described above, a simpler heat transfer performance can be achieved in that It has an advantageous advantage over shaped impressions.

For example, while using highly contaminated fluids, such as exhaust gases from the engine, the risk of narrowing and blocking the channels 6 as gaseous components, particularly soot and / or hydrocarbons (HC), accumulate. This applies to both the embodiment according to FIG. 2 and FIG. 6. Thus, the bulges of the webs 5 are designed to bulge out in the same orientation at all times in the transverse direction, such that the free channel distance between neighboring webs 5 does not change or only slightly changes. Thus, in the longitudinal direction, the webs have a wave shape parallel to one another in the transverse direction.

However, depending on the use, the bulges of neighboring webs 5 are oriented exactly in opposite directions with respect to each other, alternately narrowing the channel 6 as much as possible and then as wide as possible again. It may be advantageous to arrange the webs 5. An embodiment of the foregoing arrangement is shown in embodiment 6.13 of FIG. 6A. The alternating narrowing and widening of these channel cross-sections is an intercooler, refrigerant cooler, oil cooler or exhaust gas for low pressure Exhaust Gas Recirculation (EGR) applications or high pressure EGR applications with conventional soot and / or hydrocarbon (HC) emissions. It allows for an additional increase in performance for applications such as coolers and the like, and the deposits therein are not fatal. In this case, depending on the requirements, a proper compromise with pressure build-up caused by vortexing and narrowing should always be considered.

In the 6.14 and 6.15 embodiments of FIG. 6A, another option is shown which allows the sidewalls and web / neighbor webs to buckle with only one impression, where the die as well as the channel width is different. Or cover more than that portion of the neighboring web (s). In addition to the variants shown in the 6.14 and 6.15 embodiments of FIG. 6A, all the above-described combinations of web buckling for channel impression direction are also conceivable.

For the dimensional stability of the outer dimension of the extruded tube, it is advantageous not to use the impressions to bulge the closing narrow sides 3, 4. In this case, however, in all of the lateral outer channels, only the wavy protrusion of the web placed closer to the center of the tube occurs, while the outer wall remains undeformed. Thus, depending on the application, in order to minimize the risk of clogging of the gas channel in the first type or in the second type by further narrowing the distance between the web 5 in the area of the bulge and the outer narrow sides 3, 4. It is advantageous to provide larger or smaller flow cross sections to the outer channels, as well as to achieve high turbulence similarly to the outer channels 6 as well as the inner channels. If there are no special requirements for the outer dimensions of the extruded tube, it may be convenient to naturally also provide impressions on the narrow sides 3, 4 and bulge them in the transverse direction.

Fixing the extrusion tube to the bottom and forming the tube ends:

In order to secure the extruded tube to the bottom of the tube, embossing is formed in the end regions so as to allow a fixed insertion of the extruded tube using a constant gap on the outer periphery at the bottom and to ensure good fixation of the extruded tube-bottom connection. It is advantageous not to. Another reason is to allow a predetermined widening of the extruded tube for securing the extruded tube and the bottom via a common contact surface.

The required distance of the profile end to the first embossing depends in particular on the depth of the impressions. The distance is chosen such that the original tube shape in the fixed area is not deformed at all or only a very small deformation occurs. In typical case heat exchangers dimensioned for motor vehicles, the distance means 2 to 5 mm, in particular 4 to 8 mm. In a special case, the above distance may be exceeded.

Bending of Embossed Extrusion Tubes:

For example, the greatest advantage of an extruded tube heat exchanger compared to other heat exchange tubes, such as stainless steel tubes, is the great design flexibility, especially due to the freedom of choice for bending of the extruded tubes.

In the case of the bending of the extruded tube, it is particularly advantageous to prevent too large deformation and closure of the individual channels when impressions are not used in the region of the bending. Alternatively, in the bending area, only the impression depth may be reduced or only the embossing of the webs or the narrowing of the channel walls may be provided, for example. In the manufacturing process, the tubes are first embossed and then bent to the desired shape.

Manufacturing method:

The preparation of the impressions can preferably be done in two alternative or cumulative ways:

1) The extruded tube is embossed using at least one roller-shaped tool. Such a roller 9 is shown in FIG. 7. Preferably, at least two counterrotating tool rollers are used so that both the upper side wall 1 and the lower side wall 2 are embossed in one operation.

2) The extruded tube is embossed by a die set or several types of single press die.

For both types of production, the impression can be produced in both single and multi-step manner through several sets of embossing rollers or dies provided in turn in the manufacturing direction.

During the manufacturing process, the extrusion tube is held in place using at least one holding function before and / or after the embossing step to prevent bending of the extrusion tube. The extrusion tube is ensured not to move laterally during the embossing process by lateral roller guidance. If the above-mentioned holding action can only partially prevent the extrusion tube from squeezing, it is corrected by a subsequent operation to perform stretching or resizing of the extrusion tube using another roller set or press. Can be.

The embossing process with rollers has the advantage that it can be carried out with a continuous conveying motion of the extruded tube, while in the case of manufacturing with die sets, the speed control of the conveying motion is usually required.

In order to be able to optimally fix the extruded tube to the floor later, it is important that in the area of profile separation there should be no change or no embossing on the cross section of the extruded tube. This can be accomplished by several methods:

a) The distance of the impressions is very large, allowing separation of the extrusion tube.

b) embossing is omitted at the separation point.

The latter method may be provided for embossing by suitable geometry of the rollers, for example embossing rollers. In this case, the roller circumference is always an integer multiple of the later profile length. Another possibility to provide a sufficiently wide fixing area is to make the provision of the roller variable so that the embossings are shaped or not depending on the provision of the roller.

Another advantage of manufacturing with rollers is that various profile variants can be produced in a very simple way using the same production line by replacing the rollers.

In addition to the replacement of the embossing rollers, alternatively only one embossing roller may be used, and the raised areas for embossing may be replaceably positioned. In this case, the work is carried out using a basic roller, and variable embossing sets can be used. Alternatively, it may be envisaged to drag and drop a sheathing body that provides the desired embossing arrangement over a basic roller with or without some embossing. In both cases, work is carried out with only one basic roller.

In order to emboss the extrusion profile using die sets, optionally to achieve a large sawing region, the dies must be completely or partially suspended at the sawing or fixed region, thereby embossing Or only very faint embossings should be made.

Thus, the manufacturing sequence for the embossed extruded tube is as follows:

1) the extruded tube to a prefabricated length minus fabrication-related stretching in the embossing process, or to a bar material having a multiple of the later tube length, or particularly preferably for the embossing process Available in coil-shaped continuous material

2) Embossing of extruded tubes using rollers or die set

3) correction of bending using extension and / or standardizing rollers / press

4) Separation of Extruded Tubes

5) bending of extrusion tubes

6) Cleaning of the extruded tubes

The sequence of steps described above is chosen so that they can be very simply linked to one another to form a manufacturing line that is both cost effective and very simple to realize.

Separation of Extruded Tubes:

Preferably the separation is made by a saw that rotates simultaneously in the embossing process, but may be done in a separate sawing process after the embossing process. Alternatively, the separation of the extruded tubes can also be accomplished by drawing a cutting line in advance and then tearing off the tubes. This method is advantageous in that no chips are produced and no additional saw lubricant is required. As a result, depending on the application, the subsequent grooming process may be omitted, in whole or in part.

material:

In principle, embossed extruded tubes are made of extrudable material. All aluminum alloys, preferably Al alloys, more preferably AlMn alloys, AlMg alloys, AlMgSi alloys, are advantageous for application to heat exchangers such as exhaust coolers, oil coolers, refrigerant coolers and intercoolers.

If the extruded tube is used as a gas delivery extrusion tube for a corrosion-critical application, e.g., an exhaust gas cooler or a low pressure intercooler, contamination in an extruded tube with the following percent by weight Many corrosion studies have shown that a high degree of corrosion resistance is achieved:

Silicon (Si): Si <1%, preferably Si <0.6%, more preferably Si <0.15%

Iron (Fe): Fe <1.2%, preferably Fe <0.7%, more preferably Fe <0.35%

Copper (Cu): Cu <0.5%, preferably Cu <0.2%, more preferably Cu <0.1%

Chromium (Cr): Cr <0.5%, preferably 0.05% <Cr <0.25%, more preferably 0.1% <Cr <0.25%

Magnesium (Mg): 0.02% <Mg <0.5%, preferably 0.05% <Mg <0.3%

Zinc (Zn): Zn <0.5%, preferably 0.05% <Zn <0.3%

Titanium (Ti): Ti <0.5%, preferably 0.05% <Ti <0.25%

In particular, the high corrosion resistance of the extruded tube described above can generally be achieved when the particle size measured in the extrusion direction is smaller than 250 μm, preferably smaller than 100 μm and more preferably smaller than 50 μm.

Impression Depth:

The specific depth of the impression depends greatly on the application. However, in view of the thinning of the material and the pressure loss caused by the impression, the impression depth is less than 75%, preferably less than 45%, more preferably less than 45% of the pure tube height (b). It has been proved that advantageously less than 30% is advantageous.

Distance of impressions:

The distance of the impressions to each other also varies greatly depending on the application. However, particularly advantageous ranges may be as follows:

1) 0 to 10 times the pure tube height b, preferably the pure tube height b, in the longitudinal direction based on the embossing of one side wall 1 to the embossing of the other side wall 2 0 to 6 times, more preferably 0 to 3.5 times the pure tube height (b).

2) 0 to 8 times the pure tube height b, in the longitudinal direction, based on embossing used to reduce the channel height, to embossing used to bulge the webs on one sidewall, Preferably 0 times-6 times the pure tube height b, More preferably 0 times-3 times the pure tube height b.

Length of Impressions:

The length of the impressions also varies greatly depending on the application. However, particularly advantageous ranges relating to tube width or channel width can be as follows:

In the embodiment according to FIG. 2, the length of the impression should be in the range of 100% to 25% of the tube width, preferably 90% to 35% of the tube width, more preferably 80% to 45% of the tube width. do.

In the case of the embodiment according to FIG. 6, the length of the impression should range from 130% to 25% of the channel width, preferably from 90% to 35% of the channel width, more preferably from 75% to 45% of the channel width. do.

In the case of the not shown embodiment, the length of the impression is in the range of 325% to 25% of the channel width, preferably 250% to 35% of the channel width, more preferably 215% to 45% of the channel width.

For example, soldering outer fins for refrigerant coolers, intercoolers:

When the outer fins are additionally attached to the embossed extruded tube, for example, in the cross-flow cooler, the impressions are arranged in the transverse direction to ensure the best possible soldering of the outer fins. Care must be taken to place them slightly offset. For this purpose, the arrangement of the impressions shown in the 2.3 to 2.9 embodiment of FIG. 2 and the 6.6 to 6.10 embodiment of FIG. 6 is particularly suitable. In the arrangement of impressions shown in the embodiments 6.6 to 6.10 of FIG. 6, the distance of similar impressions in channels adjacent to each other in the longitudinal direction is not an integer multiple of the fin density but rather smaller or larger, particularly preferably of a fin depth. It is advantageously realized in the range of k / 3 (k = 1, 4, 7, 10, ...) to n / 3 (n = 2, 5, 8, 11, ...), so that the best possible soldering of the outer fin is achieved. To help.

Preferred embodiments of the extrusion tube cross section are not impressed:

It has been proved that hydraulic diameters in the range of 2 mm to 5 mm are particularly preferred for realizing the concept of the present invention. The size of this range, as explained in detail using FIG. 8, balances the tendency to achieve heat transfer in the extrusion tube on the one hand as best as possible and on the other hand to reduce pressure loss. Particularly advantageous heat transfer is realized while realizing an advantageous or acceptable pressure loss. In addition, it has been proved that hydraulic diameters in the range of 3 mm to 3.4 mm, more preferably 3.1 mm to 3.3 mm are particularly preferred. In particular, with regard to the latter range of 3.1 mm to 3.3 mm, it is evident that the hydraulic diameter of about 3.2 mm is most suitable. Although it is fundamentally impossible to prevent fouling of the extruded or heat exchanger tubes within the above-mentioned range, many experiments have shown that in this range the contamination is stabilized in such a way that the reduction in performance is kept at a relatively low level. Is showing. In the range of hydraulic diameters outside the above-mentioned ranges, as the extrusion tube is operated longer, the contamination is expected to increase with an increase in pressure loss, so for the above-mentioned hydraulic range, the pressure loss is relatively low. It is estimated to be stable to the level. The possible suboptimal heat transfer performance of the heat exchanger is not further reduced by continued operation of the heat exchanger. Conversely, in the case of hydraulic diameters outside the above-mentioned ranges, during subsequent further operation, an increase in pressure loss and in the worst case clogging of the channels may occur.

The extrusion tube according to the concept of the present invention can be advantageously used in the environment of high pressure exhaust gas recycling and low pressure exhaust gas recycling. In addition, applications for intercooling or refrigerant cooling are also possible. In all fields of application, in particular in the aforementioned and similar fields, according to the concept of the present invention by selecting the hydraulic diameter within the range of 1.2 mm to 6 mm, for improving heat transfer An increase in the number of webs can be avoided. However, many experiments show that the choice of hydraulic diameter range, which is optimized for low pressure exhaust gas recirculation, high pressure exhaust gas recirculation, or intercooling, can vary. In the case of high-pressure exhaust recirculation, the increase in pressure loss and the risk of increased clogging or severe contamination of the channels by such as soot particles are relatively problematic. In the case of high pressure heat exchangers, the range of hydraulic diameters of 2.5 mm to 4 mm, in particular 2.8 mm to 3.8 mm, has proved to be particularly advantageous.

For low pressure exhaust gas recirculation, there is very little or no soot, so smaller hydraulic diameters may be used than for high pressure EGR coolers. In the case of low pressure heat exchangers, the range of hydraulic diameters from 2 mm to 3.5 mm, in particular from 2.5 mm to 3.5 mm, has proved to be particularly advantageous.

In order to increase the corrosion resistance, it has proved particularly advantageous to select a ratio of web thickness and channel cover thickness below the value of 1.0. In other words, to increase the corrosion resistance, it is advantageous to provide a channel cover with a larger wall thickness than the web. This is particularly advantageous with regard to the design of the extruded tube, at least the channel cover being made of aluminum as its material.

This is also the case in particular in the case of extruded tubes based on aluminum material, on the one hand in a manner that ensures sufficient corrosion resistance and on the other hand in a manner in which a sufficient number of extruded tubes are provided in the available installation space of the heat exchanger. This proved to be fundamentally related to optimizing channel cover thickness. The installation space for the heat exchanger in the engine is usually somewhat limited, so designing the channel cover thickness not too thick to provide as many extruded tubes as possible to the heat exchanger is basically within the scope of improvement. According to a particularly preferred improved aspect of the present invention, it has proved to be particularly advantageous that the ratio of hydraulic diameter and channel cover thickness is in the range of 0.8-9. This range has proved particularly suitable for extrusion tubes based on aluminum material, in particular for extrusion tubes in which at least the channel cover is based on aluminum material. Furthermore, the range is advantageously in the range of 1.2 to 6.0, in particular in the range of 1.4 to 6, with respect to the design of the channel cover thickness (installation space conditions, corrosion resistance) and the hydraulic diameter (heat transfer, pressure loss).

The concept of the invention and / or one or more of the above described improved aspects are perimeters that can be wetted by the outer perimeter of the extrusion tube and the first fluid for the exhaust cooler, individually or in combination. Particularly advantageous is the dimension of the extruded tube that achieves a ratio of) within the range of 0.1 to 0.9, especially 0.1 to 0.5. Many experiments performed in this respect show that, within the scope of the dimensions specified above, the behavior of the extruded tube is particularly advantageous with regard to the above-mentioned problems.

With respect to the manufacturing aspects and the above-mentioned problems, extrusion tubes are particularly suitable, in which the web is arranged as a full web in one end of the tube and at the other end in the channel cover inner side. In particular, the tube cross section may only have complete webs. The complete web is made continuously, with no openings between the first channel cover inner surface and the second channel cover inner surface. This enables the realization of an extruded tube having a hydraulic diameter in accordance with the concept of the present invention, as described with reference to FIGS. 9A and 9B.

It has also proven to be advantageous for such extruded tubes that the web is arranged as a partial web at one end on the inner side of the channel in the tube cross section and at the other end protrudes into the inner space. As described with reference to FIGS. 11A and 11B in addition to FIGS. 10A and 10B, the hydraulic diameter can be realized in a particularly advantageous manner by the extrusion flow channel according to the inventive concept.

It has been clarified that two partial webs may preferably be arranged with the opposite side faces facing at the other end. Alternatively or in combination with the arrangement of the partial webs described above, two partial webs may be arranged with distal sides that are laterally offset relative to each other at the other end. Preferably, the partial web and the full web are alternately arranged.

It has proved particularly advantageous to make the dimensions and arrangement of the partial webs as follows. According to a particularly preferred improved aspect, the ratio of the distance between the two partial webs, in particular two opposing partial webs and / or the two partial webs offset from each other, to the height of the tube cross section is 0.8 or less, in particular 0.3 It is in the range of ˜0.7. Preferably, the ratio of the distance of the first partial web to the full web relative to the distance of the second partial web to the full web is in the range of 0.5 to 1.0, preferably in the range of 0.6 to 0.8.

8 shows the ratio of the perimeter that can be wetted by a fluid such as exhaust gas and the outer perimeter of the extrusion tube as a function of hydraulic diameter. Preferred ratios derive from the region of the aforementioned shape of the preferred hydraulic diameter of 2 mm to 5 mm, in particular 2.8 mm to 3.8 mm. It is clear from FIG. 8 that the ratio must be in the range of 0.1 to 0.5 to achieve improved levels of heat exchange and pressure loss. In this case, FIG. 8 serves as an example for the extrusion tube profile shown in more detail in FIG. 10B. A comparable trend can be observed in additional structural designs of the cross section through which the fluid in the extrusion tube passes, which is explained in more detail below. FIG. 8 is an opposition to the height of the tube section and the ratio described for inter alia of different web distances a, FIG. 10B (two examples where a = 2 mm, a = 5 mm). It shows the ratio described for various values of the ratio of the distance between the two partial webs (indicated by k). The ratio k described by the arrows in FIG. 8 should be within 0.8, preferably in the range of 0.3 to 0.7. In this case, the ratio k of the distance e between two opposing partial webs to the height b of the tube cross section increases from 0.25 to 0.75 in the direction of the arrow. This analysis applies to both the exhaust gas cooler within the range of high pressure design in the exhaust gas recirculation system and the exhaust gas cooler within the range of low pressure design in the exhaust gas recirculation system.

Structural designs for the cross section of various preferred extrusion tubes are described with reference to FIGS. 9A-11B. In this case, other preferred combinations and modifications of the features of the embodiments specifically illustrated in the figures are possible, and are hydraulically within the range of 1.5 mm to 6 mm, preferably 2 mm to 5 mm, more preferably 2.8 mm to 3.8 mm. Diameter can be achieved. In particular, the embodiments shown in the figures show a variant in which the channel cover thickness and the web thickness d are the same or similar, and yet another variant in which the ratio of the web thickness d and the channel cover thickness s is less than 1.0 mm. Shows. Thus, wall thicknesses or similar dimensions of the partial webs may vary depending on the purpose to be achieved.

9A and 9B show variations of two extrusion tubes 61, 61 ′. Here, the cover thickness s of the extruded tube 61 ′ shown in FIG. 9B is thicker than the web thickness d, while in the case of the extruded tube 61 shown in FIG. 9A the two thicknesses are substantially different from each other. The variations are different in that they are identical. Here, like reference numerals in the drawings are used for like features.

Flow channels 61, 61 ′ are formed as a whole extruded profile, ie as an extruded channel cover with the extruded webs. The flow channels 61, 61 ′ thus have a channel cover 63 with an inner space 67 surrounded by a channel cover inner surface 65 and designed for heat exchange guidance of the first fluid in the form of exhaust gas. do. In addition, the flow channels 61, 61 ′ are formed as extrusion profiles integrated with the channel covers 63, 63 ′, and five webs arranged on the channel cover inner side 65 in the interior space 67. Has 69. The web 69 extends completely parallel to the flow channel axis, along the flow path formed in the housing of the heat exchanger. The cross section through which the fluid across the flow channel axis passes is designed to guide the exhaust gas into the interior space 67. The design is made based on the hydraulic diameter d _h associated with the distances a and b given for the extrusion tubes 61, 61 ′ at the bottom right of FIG. 9B. The hydraulic diameter is four times the ratio of the fluid-flow cross-sectional area to the perimeter that can be wetted by the exhaust gas. Wherein the fluid-flow cross-sectional area is the product of distances a and b, and the wettable perimeter is twice the sum of the distances a and b. The distance a represents the cross-sectional width of the flow line 74, divided by the webs 69, and the distance b represents the height of the flow line 74.

In the flow channels 63 and 63 'and also in the flow channels described in more detail below, the wall thickness s is in the range of 0.2 mm to 2 mm, preferably in applications where corrosion is a problem. It is in the range of 0.5 mm to 1.4 mm and preferably in the range of 0.3 mm to 0.8 mm for applications where corrosion is not a problem. The height b of the flow path 74 or the height of the internal space 67 is in the range of 2.5 mm to 10 mm, preferably 4.5 mm to 7.5 mm. The width a of the channel 74 in the transverse direction is in the range of 3 mm to 10 mm, preferably 4 mm to 6 mm.

10A and 10B show two additional variations of the most preferred embodiment of the extruded tube 71, 71 ′, where only the wall thickness of the channel covers 73, 73 ′ differs from the wall thickness of the web 79. Show them. The flow channels 71, 71 ′ also have webs of the form in which the full webs 79 and the partial webs 79 ′ are arranged alternately in succession. The extrusion tubes 71, 71 ′ are in turn formed entirely as one extrusion profile, with the channels 74 being formed in turn by the distance between the two complete webs 79. The hydraulic diameter of the flow-through cross section for the extruded tubes 71, 71 ′, shown in FIGS. 10A and 10B, is specified at the bottom of FIG. 10B. The two partial webs 79 ′ are arranged to have distal side sides 76 facing each other.

11A and 11B show two additional and alternative embodiments of the most preferred extrusion tube 81, 81 ′ arranged so that the two partial webs 89 ′ have distal side sides 86 that are laterally offset relative to one another. Other variants are shown. The hydraulic diameter d _h of the profile shown is obtained from the formula specified at the bottom of FIG. 10b, where a1 is replaced by a4.

The ratio of the distance a3 of the first partial web 89 'to the full web 89 to the distance a4 of the second partial web 89' to the full web 89 is preferably from 0.5 mm to 1.0 mm, More preferably, it exists in the range of 0.6 mm-0.8 mm. The distance e between two subwebs 79 'facing each other relative to the height b of the tube cross section and / or the distance e between two subwebs 89' offset relative to each other is basically 0.8mm or less, especially 0.3mm ~ 0.7mm.

Each preferred extrusion tube shown in FIGS. 9A-11B has impressions and bulges in accordance with the aforementioned embodiments to optimize not only pressure drop but also turbulence and heat transfer in specific applications. It is provided according to the invention.

In addition to the foregoing procedure for the impressing of the tube wall and the tube web, in particular, for the extrusion profiles shown in FIGS. 10A, 10B, 11A and 11B, full webs and half-webs Embodiments with exclusive buckling of are also advantageous. Due to the large number of webs and / or half-webs, the impression of the tube wall can block the flow channel. Thus, depending on distance e, in particular for the profiles shown in FIGS. 10A, 10B, 11A and 11B, only the webs or half-webs buckle near the web attachment with optional impressions. It is often more advantageous to allow to do so, and to allow the tube walls to be impressed to the minimum possible. This applies especially when e <1 / 3b.

12 and 13 show further embodiments 91, 101 of cross sections of extrusion tubes without bulges, respectively. In each case, there are partial webs 92, 102 extending transversely from the webs 5 into the channels 6. The partial webs are arranged at the same height in the case of the embodiment shown in FIG. 12, and are arranged at different heights in the case of the embodiment shown in FIG. 13.

The figures according to FIGS. 12 and 13 depend on the scale, so that specific dimensional ratios of the shown dimensions can be obtained from the dimensions.

Each feature of the various embodiments described so far can be combined with each other according to requirements.

Claims (15)

In the extruded tube for heat exchanger,
At least nearly parallel two extending in the longitudinal direction (z) and transverse direction (y) of the extrusion tube and connected by two outer narrow sides (3, 4) provided in the vertical direction (x) of the extrusion tube; Outer sidewalls 1, 2; And at least one continuous web extending between the outer sidewalls 1, 2 in the longitudinal direction z and in the vertical direction x to divide at least two channels 6 of the extrusion tube. 5)
At least one of the outer sidewalls 1, 2 has impressions 7 and both bulges of the outer sidewalls 1, 2 protruding into the channels 6. And bulges 7 of the web 5 extending substantially in the transverse direction y are formed by the impressions 7,
Extruded tube for heat exchanger, characterized in that the bulges (7) of the web (5) have a controlled direction with respect to the transverse direction (y). The method of claim 1,
At least one of the channels (6) of the extrusion tube formed in the longitudinal direction has a regular wave-shaped course with respect to the transverse direction (y). The method according to claim 1 or 2,
Extruded tube for heat exchanger, characterized in that the lateral (y) distance between two neighboring webs (5) is substantially constant. 4. The method according to any one of claims 1 to 3,
At least one of the impressions (7) has an elongated form, the extrusion tube for the heat exchanger, characterized in that the majority of the webs (5) are bulged out by such an impression (7). The method of claim 4, wherein
The extrusion tube (7) having an elongated shape has an orientation angle with respect to the transverse direction (y). The method of claim 5,
The azimuth angle is about 0 ° to 45 °, preferably about 20 ° to 45 °, more preferably about 28 ° to 42 °. The method according to any one of claims 1 to 6,
Extruded tube for heat exchanger, characterized in that at least one of the impressions (7) substantially overlaps at least one web (5). The method according to any one of claims 1 to 7,
Extruded tube for heat exchanger, characterized in that at least one of the impressions (7) does not overlap any web (5). The method of claim 8,
And said impression (7) has a direction opposite to said transverse direction (y). 10. The method of claim 9,
Extrusion angle for the impression 7 relative to the transverse direction y is about 0 ° to 45 °, preferably about 25 ° to 45 °, more preferably about 30 ° to 40 °. tube. The method according to any one of claims 1 to 10,
Extruded tube for heat exchanger, characterized in that at least one of the impressions (7) is made in the form of a winglet such as a long extended winglet. The method of claim 10,
The impression 7 of the winglet type has a length and width ratio of 1.2 to 5, preferably 2 to 5, more preferably 2.5 to 3.2, or preferably 1.5 to 3, more preferably 1.8 to 2.5. Extrusion tube. The method according to any one of claims 1 to 12,
Extruded tube for heat exchanger, characterized in that the directions of at least some bulges (7) of neighboring webs (5) having substantially the same height in the longitudinal direction are the same. An automotive heat exchanger comprising an extrusion tube for a heat exchanger according to any one of claims 1 to 13. The method of manufacturing an extruded tube for a heat exchanger according to any one of claims 1 to 49,
Preparing the extrusion tube by an extrusion process; And then
Forming impressions on the outer sidewalls (1, 2).

Images