EP1331464A2 - Heat exchanger - Google Patents

Abstract

The heat transfer system, between a liquid and a gas and especially for vehicles, has a number of spaced and parallel tubes (2) with ribs (7) between them and each rib has a number of successive and parallel gills (10). Each gill has at least two longitudinal sections (12,13), where two neighboring sections are angled in opposite directions across the longitudinal gill line. All the gills on one rib are arranged so that successive longitudinal sections are angled in the same direction.

Description

The invention relates to a heat exchanger, in particular for a motor vehicle, for heat transfer between a liquid and a gas, with the features of the preamble of claim 1.

Such a heat exchanger is known for example from DE-OS 14 51 216 known and has a plurality of tubes which are parallel to each other and spaced are arranged from each other. The tubes are inside in the tube longitudinal direction permeable by the liquid and outside transversely to the tube longitudinal direction flowed around by the gas. Between the tubes are in the gas flow path each arranged a plurality of ribs, the heat-transmitting connected to the pipes. These ribs extend with their Longitudinal direction transverse to the tube longitudinal direction and serve as Spacer for the pipes. Suitably, all between two adjacent ribs arranged ribs combined into a ribbed band.

Each rib has several gills, one behind the other in the rib longitudinal direction and are arranged parallel to each other. These gills extend with its longitudinal direction approximately transversely to the tube longitudinal direction and across the Fin longitudinal direction. Furthermore, the gills are transverse to the gill longitudinal direction inclined relative to the rib longitudinal direction and can thereby at a gas admission of the heat exchanger, the gas flow of one rib side to the other rib side lead. These gills initially cause a constant rebuilding of thermal boundary layers, which are relatively thin on average due to the short start-up lengths and thereby a relatively good heat transfer between the gas and the Allow gills. By the inclination or inclination of the gills is caused to the incoming gas, a transverse velocity component is impressed in the direction of the tube longitudinal direction. It comes thereby to a deflection of the gas in the direction of the tube longitudinal direction. This ensures that the gills are not in Totwassergebiet from each other lie, but are flowed largely undisturbed by the gas can. Nevertheless, a largely vertical flow direction Through the entire heat exchanger, the inclination of the Gills, ie the direction of the gill exhibition in about half of Rib length reversed. That is, the gills of each rib are in one first rib longitudinal section inclined in the same direction to each other, while the Gills in a second rib longitudinal section in the same direction to each other and are inclined in opposite directions to the gills of the first rib longitudinal section. Furthermore, all are arranged side by side in the tube longitudinal direction Ribs arranged side by side in the tube longitudinal direction Gills inclined in the same direction. This construction results for the gas with the flow through the heat exchanger, a double deflection transverse to the tube longitudinal direction.

At their longitudinal ends, the tubes are each provided with a container for Collecting and / or distributing and / or diverting the liquid connected. In the vicinity of these containers, the deflection of the gas flow through the Gill inclination impeded. This creates a pressure gradient between the containers on, the flow resistance of the heat exchanger elevated. Furthermore, the heat transfer performance of Ribs starting from a soldered to the respective tube foot up towards the middle of the rib, resulting in a corresponding on the gas side Temperature gradient forms. As with the flow through the heat exchanger usually no speed component in gudgeon longitudinal direction occurs, the middle portion of the gas flow increases in heat transfer in only a small part. To improve the rib efficiency, is it possible to measure the distances between adjacent pipes and thus reducing the gill length or increasing the rib thickness. However, these measures increase the weight and the costs as well as the gas-side flow resistance of the heat exchanger.

The present invention deals with the problem, for a Heat exchanger of the type mentioned an improved embodiment specify, in particular, a relatively high heat transfer performance achieved at a relatively small pressure loss.

This problem is solved by the subject of the independent Claim. Advantageous embodiments are the subject of the dependent Claims.

The invention is based on the general idea of designing the gills in such a way that that the inclination of the gill transverse direction relative to the Rib longitudinal direction along the longitudinal gill direction in adjacent Gill longitudinal sections reversed. The gills thereby show respect their longitudinal direction a propeller-like distortion. That means each one Gill in the one gill longitudinal section the gas flow from the first Rib side leads to the second rib side and in the other gill longitudinal section from the second rib side to the first rib side. at a corresponding arrangement and distribution of these gill longitudinal sections may be the cross-flow components of the gas flow be enlarged, thereby increasing the heat transfer between gas and Gill or rib increased.

According to a particularly advantageous embodiment, all gills a rib be arranged so that the one another in the rib longitudinal direction following gill longitudinal sections are inclined in the same direction. Through this Measure acting in the rib longitudinal direction consecutive Gills for deflecting the gas flow in the same direction together, causing the flow resistance of the heat exchanger reduced.

In a particular embodiment, a certain number of in Pipe longitudinal direction juxtaposed ribs one each Form rib group, wherein the ribs of a rib group all Gills are arranged so that the one another in the tube longitudinal direction following gill longitudinal sections are inclined in the same direction, wherein in the Ripping adjacent rib groups the gill longitudinal sections of the one Rib group in opposite directions to the gill longitudinal sections of the other Rib group are inclined. By this arrangement, the repeated Gill alignment over several ribs and then changes the Tilt direction or twisting direction. After the same number of Ribs is then the twisting direction or the direction of inclination of the single gill longitudinal sections again reversed. The trained thereby Rib groups thus have alternating tilt directions or twisting directions in their gills, which is a low pressure loss System generate counter-rotating vortices. This vortex system leads on the one hand to a gas exchange in the tube longitudinal direction and on the other hand in Fin longitudinal direction. This results in an improved turbulence the gas flow in the middle of the ribs. Overall, can thereby increasing the heat transfer between gas flow and ribs become.

For an advantageous development, the number of ribs in the rib groups be chosen so that the rib groups in the tube longitudinal direction extend as far as adjacent tubes transversely to the tube longitudinal direction spaced apart from each other. Due to this design can at the Flow through the heat exchanger essentially cylindrical vortex generated at relatively low pressure losses a particularly ensure favorable heat transfer.

Other important features and advantages of the invention will become apparent from the Subclaims, from the drawings and from the associated description of the figures based on the drawings.

It is understood that the above and the following still features to be explained not only in the specified combination, but also usable in other combinations or in isolation are without departing from the scope of the present invention.

A preferred embodiment of the invention is shown in the drawings and will be explained in more detail in the following description, where like reference numerals refer to the same or functionally identical or refer to similar components.

Fig. 1

eine Ansicht in Rippenlängsrichtung auf einen Wärmeübertrager nach der Erfindung,

Fig. 2

eine vergrößerte Darstellung eines Ausschnitts II aus Fig. 1,

Fig. 3

eine Schnittansicht der Darstellung aus Fig. 2 entsprechend den Schnittlinien III in Fig. 2,

Fig. 4

eine Ansicht wie in Fig. 2, jedoch einer anderen Ausführungsform,

Fig. 5

eine Ansicht wie in Fig. 3, jedoch entsprechend der Ausführungsform gemäß Fig. 4.

Show, in each case schematically,

Fig. 1

a view in the rib longitudinal direction on a heat exchanger according to the invention,

Fig. 2

an enlarged view of a section II of Fig. 1,

Fig. 3

2 shows a sectional view of the illustration from FIG. 2 corresponding to the sectional lines III in FIG. 2,

Fig. 4

a view as in Fig. 2, but of another embodiment,

Fig. 5

a view as in Fig. 3, but according to the embodiment of FIG. 4th

1, a heat exchanger 1 a plurality of tubes 2, the parallel to each other and spaced from each other are. The tubes 2 lie in a plane that in Fig. 1 of the drawing plane equivalent. The tubes 2 are shown at their in Fig. 1 below Longitudinal ends each with a lower container 3 and at their in Fig. 1 above shown upper longitudinal end with an upper container. 4 connected. The tubes 2 are in their interior in their by a double arrow symbolized pipe longitudinal direction 5 can be traversed by a liquid. The containers 3 and 4 serve for collecting and / or distributing and / or Redirecting the fluid flow.

According to a preferred application, it is the heat exchanger 1 around the heat exchanger 1 of a motor vehicle. For example it is the so-called "radiator" of the engine cooling circuit or around a radiator or around a condenser or around an evaporator an air conditioner. In the preferred embodiment shown here it is the heat exchanger 1 is a so-called "Flat tube heat exchanger", in which the tubes 2 as flat tubes are trained; that is, the tubes 2 are transverse to their longitudinal direction 5 are significantly larger in the rib longitudinal direction 8 than in the rib transverse direction 9. The flat tubes can also be soldered against each other Slices are built, it being on the inner structure of the slices or pipes 2 does not arrive here.

Since the tubes 2 are spaced from each other, they are transverse to the outside Tube longitudinal direction 5 and substantially perpendicular to the heat exchanger plane, ie perpendicular to the plane of the drawing, from a gas, e.g. Air, flow around.

Between adjacent tubes 2 are in the gas flow path respectively Rib bands 6 arranged, which are zigzag-shaped wavy or folded, wherein the individual folds or corrugations form ribs 7, each with the tubes 2 are heat transfer connected. In particular, the Ribs 7 and the rib bands 6 with the tubes 2 soldered.

The ribs 7 extend with their in Fig. 3 by a double arrow symbolized longitudinal direction 8 transversely to the tube longitudinal direction 5. The rib longitudinal direction 8 thus runs substantially parallel to the flow of the the heat exchanger 1 acting gas. The ribs 7 and the Rib bands 6 can simultaneously as spacers for the tubes. 2 serve.

In Figs. 2 and 4, the detail II of Fig. 1 is shown enlarged, wherein the views in Figs. 2 and 4 by 90 ° with respect to the illustration according to Fig. 1 are rotated. In Figs. 2 and 4, the structure of a special Ribbed band 6 shown in more detail. In these embodiments, the Folding or corrugation of the ribbed belt 6 designed so that ribs 7, the are arranged adjacent to each other in the tube longitudinal direction 5, so are positioned so that they transversely to the rib longitudinal direction. 8 extending, symbolized in Fig. 2 by a double arrow rib transverse direction 9 parallel to each other. In another embodiment, are the rib bands 6 as in Fig. 1 zig-zag-shaped corrugated or folded, so that the ribs 7 inclined relative to the rib transverse direction 9 are and are only substantially parallel to each other:

According to FIGS. 2 to 5, the ribs 7 each have a plurality of gills 10, which are arranged one behind the other in the rib longitudinal direction 8. A Longitudinal direction 11 of the gills 10 extends transversely to the rib longitudinal direction eighth and thus coincides with the rib transverse direction 9. At each rib 7 are the gills 10 with respect to their gill longitudinal direction 11 parallel to each other arranged. Due to the parallel or substantially parallel alignment the ribs 7 are the gills 10 also adjacent Ribs 7 corresponding to FIG. 2 also with respect to their gill longitudinal direction 11 arranged parallel or substantially parallel to each other.

According to the invention, each gill 10 has a plurality of gill longitudinal sections 12 and 13. In FIGS. 2 to 5 are two different embodiments by way of example shown in terms of the number of gill longitudinal sections 12, 13 each gill 10 differ from each other. In the Embodiment of Fig. 2 and 3, each gill 10 has two gill longitudinal sections 12, 13, while in the embodiment according to FIGS. 4 and 5 each gill 10 has three gill longitudinal sections 12, 13. The a gill longitudinal sections 12 are shown in Fig. 2 above and in Fig. 3rd drawn with solid lines. In contrast, the other gill longitudinal sections 13 shown in Fig. 2 below and in Fig. 3rd drawn with broken lines. 2, the two Kiemenlängsabschnitte 12 and 13 formed substantially the same size, resulting in a total symmetrical deflection effect leaves.

In contrast, in the other embodiment, the one Gill longitudinal sections 13 as shown in FIG. 4 approximately in the middle of the gills 10th arranged while the other two gill longitudinal sections 12 outside adjoin the central gill longitudinal section 13. Accordingly are in Fig. 5, the outer gill longitudinal sections 12 with solid Lines drawn while the central gill longitudinal sections 13 with broken lines are entered. According to Fig. 4 are the both outer gill longitudinal sections 12 formed approximately the same size. Furthermore, the two outer longitudinal gill portions 12 are together about the same size as the central longitudinal gill portion 13th

The gill longitudinal sections 12 and 13 of the gills 10 are with respect to the Kiemenlängsrichtung 11 in opposite directions against each other wound, resulting in a propeller-like twist. By this construction is the gill longitudinal sections at each gill 10 12 symbolized in a in Fig. 3 by corresponding double arrows, transverse to the gill longitudinal direction 11 extending gill transverse direction 14 opposite the rib longitudinal direction 8 inclined. At the same time, the other gill longitudinal sections 13 with their gill transverse direction 14, the in Fig. 3 is shown by dotted double arrows, also inclined to Rib longitudinal direction 8, however, is the inclination of the other gill longitudinal sections 13 opposite to the inclination of a gill longitudinal sections 12 oriented.

Furthermore, each gill 10 is arranged at each rib 7, that in the rib longitudinal direction 8 consecutive Kiemenlängsabschnitte 12 and 13 are inclined in the same direction. Referring to FIG. 3 and 5, this means that at each rib 7, the upper (see Fig. 2) or the outer (see Fig. 4) gill longitudinal sections 12 in the same way run inclined relative to the rib longitudinal direction 8. Likewise proceed in the case of each rib 7, all the lower ones (see FIG (See Fig. 4) Gill longitudinal sections 13 inclined in the same way relative to the rib longitudinal direction 8. With reference to FIG. 2, this means that the above-illustrated gill sections 12 within a rib 7 in are inclined in one direction, while the same rib 7 all shown below second gill longitudinal sections 13 in the other direction are inclined relative to the rib longitudinal direction 8. With reference to FIG. 4, this means that the externally disposed gill longitudinal sections 12 are inclined within a rib 7 in one direction, while at the same rib 7 all arranged in the middle gill longitudinal sections 13 in the other direction relative to the rib longitudinal direction. 8 are inclined.

In addition, each form one in the embodiments shown here certain number of ribs 7, in the tube longitudinal direction 5 side by side are arranged, in each case a rib group 15 or 15 ', in the 3 and 5 are marked by braces. noteworthy Here is that in the ribs 7 a group of ribs 15 all gills 10th are arranged so that all upper or outer gill longitudinal sections 12 are arranged in the same direction and that all lower or middle Gill longitudinal sections 13 are oriented in the same direction to each other. The means that in the tube longitudinal direction 5, the successive gill longitudinal sections 12 and 13 are inclined in the same direction. Furthermore, it is noteworthy that in the ribs 7 adjacent rib groups 15 and 15 ', the gill longitudinal sections 12,13 of a rib group 15 in opposite directions to the gill longitudinal sections 12, 13 of the other rib group 15 ' are inclined.

By this arrangement, the gill longitudinal sections 12,13 results for the Gas flow in the flow through the heat exchanger 1 within the Ridges 7 a vortex formation whose helical shape in particular from the Fig. 2 and 4 shows and which are designated in Figs. 2 to 5 with 16. These vortices 16 on the one hand cause a gas exchange in the tube longitudinal direction 5 and on the other hand in the longitudinal direction of the gill 11. Through this Gas exchange can be the temperature gradient between near-pipe areas the ribs 7 and the tube-distal middle portions of the ribs 7 reduced become. Overall, this improves the heat transfer between gas flow and gills 10 or ribs 7 and thus between Gas flow and tubes 5 and the liquid flow guided therein.

In the embodiment according to FIGS. 2 and 3, it is particularly advantageous to choose the number of ribs per rib group 15 or 15 'so that the tube groups 15 and 15 'in the tube longitudinal direction 5 about as far extend as adjacent tubes 2 transversely to the tube longitudinal direction 5, ie in Gill longitudinal direction 11, are spaced from each other. This allows the generated vertebrae 16 take on a substantially cylindrical shape. This is to achieve small flow resistance of particular Advantage.

In the embodiment according to FIGS. 4 and 5, it is particularly expedient to choose the number of ribs per rib group 15 or 15 'so that the pipe groups 15 and 15 'in the tube longitudinal direction 5 about halfway extend far as adjacent tubes 2 transverse to the tube longitudinal direction 5, ie in gill longitudinal direction 11, are spaced from each other. hereby can in Fig. 4 in each fin group 15, 15 'two together bordering, substantially cylindrical vortex 16 are generated, the one ensure particularly intensive mixing of the gas flow.

In the embodiments shown here, each fin group has 15, 15 ' three ribs 7 with the same direction gills 10 and first gill longitudinal sections 12 and second gill longitudinal sections 13.

The gills 10 form in the ribs 7 openings, the gills 10th because of their employment or inclination at a gas supply of the Heat exchanger 1, the gas flow from the one rib side to lead to other rib side. By the opposing flow deflection at the first gill longitudinal sections 12 and the second gill longitudinal sections 13 as well as due to the chosen arrangement and orientation the gill longitudinal sections 12,13 at adjacent ribs 7 may be form the desired vortex 16.

By the proposed embodiment of the gills 10 and by the Targeted orientation of the gill longitudinal sections 12 and 13 arise propeller-like twisting over several ribs 7 away interact and there a self-contained vortex system (vortex system) stimulate. This vortex system 16 leads to an intensive gas exchange between tube-near and tube-distant air layers, whereby all Air layers along the gas flow path in the region near the tube with high temperature difference, so that the heat transfer improves is.

In the construction according to the invention, the ribs 7 in the gill longitudinal direction 11 build relatively large, i. the tubes 2 can be relatively large Have distances from each other. This results in a special cost-effective design for the heat exchanger 1. The training of Whirl 16 only results in a comparatively low pressure loss. Furthermore, the edge regions of the tubes 2, so the transition zones between the containers 3,4 and the pipe longitudinal ends better be used for heat transfer.

Overall, this results in a heat exchanger 1, which is a very efficient Heat transfer between gas and liquid allows and at the same time generates a relatively small pressure loss for the gas flow.

In the embodiment according to FIGS. 4 and 5, the gills 10 with respect to a median plane which extends in the tube longitudinal direction 5 and in the rib longitudinal direction 8 extends between the tubes 2, formed mirror-symmetrically. This symmetry can have manufacturing advantages, in particular with respect to a distortion during continuous rolling of a Ribbed tape 6.

Claims (10)

Heat exchangers, in particular for motor vehicles, for heat transfer between a liquid and a gas, with several tubes (2), which are arranged parallel to one another and at a distance from each other, the liquid can flow through the inside in the tube longitudinal direction (5), the outside of the pipe longitudinal direction (5) are flowed around by the gas, wherein in each case a plurality of ribs (7) are arranged between the tubes (2) in the gas flow path, which are heat-transmitting connected to the tubes (2), which extend with their longitudinal direction (8) transversely to the tube longitudinal direction (5), each rib (7) having a plurality of gills (10), which are arranged in the rib longitudinal direction (8) one behind the other and parallel to each other, extending with their longitudinal direction substantially transversely to the tube longitudinal direction (5) and transversely to the rib longitudinal direction (8), which are inclined transversely to the longitudinal direction of the gill (11) with respect to the rib longitudinal direction (8), which, when the heat exchanger (1) is supplied with gas, conduct the gas flow from one side of the rib to the other side of the rib, characterized, in that each gill (10) has at least two gill longitudinal sections (12, 13), wherein two adjacent longitudinal gill portions (12, 13) are inclined transversely to the gill longitudinal direction (11) in opposite directions with respect to the longitudinal direction (8) of the rib. Heat exchanger according to claim 1,
characterized in that all the gills (10) of a rib (7) are arranged so that in the rib longitudinal direction (8) successive Kiemenlängsabschnitte (12,13) are inclined in the same direction. Heat exchanger according to claim 2,
characterized in that a certain number of juxtaposed ribs (7) each form a rib group (15,15 '), wherein the ribs (7) of a group of ribs (15,15') all gills (10) are arranged so that in the tube longitudinal direction (5) successive gill longitudinal sections (12,13) are inclined in the same direction, wherein at the ribs (7) of adjacent groups of ribs (15,15 ') the longitudinal gill portions (12,13) of a group of ribs (15) in opposite directions to the longitudinal gill segments (12,13) of the other rib group (15 ') are inclined. Heat exchanger according to claim 3,
characterized in that the number of ribs in the fin groups (15,15 ') is selected so that the rib groups (15,15') extend in the tube longitudinal direction (5) about as far or about half as far as adjacent tubes (2) transversely to the tube longitudinal direction (5) are spaced from each other. Heat exchanger according to one of claims 1 to 4,
characterized in that the ribs (7) with respect to their transversely to the rib longitudinal direction (8) extending rib transverse direction (9) are arranged parallel to each other. Heat exchanger according to one of claims 1 to 5,
characterized in that in an embodiment in which the gills (10) each have only two longitudinal gill portions (12, 13), for each gill (10) both gill-longitudinal portions (12, 13) are approximately equal. Heat exchanger according to one of claims 1 to 5,
characterized in that in an embodiment in which the gills (10) each have more than two longitudinal gill sections (12, 13), for each gill (10), the total length of all the gill longitudinal sections (12) with the one gill pointing direction is approximately equal to the total length of all gill longitudinal sections (13) with the other Kiemenausstellrichtung is. Heat exchanger according to one of claims 1 to 5 and 7,
characterized in that in an embodiment in which the gills (10) each have three longitudinal gill portions (12,13), in each gill (10) of the central longitudinal gill portion (13) is about the same size as the two approximately equal outer gill longitudinal sections ( 12) together. Heat exchanger according to one of claims 1 to 8,
characterized in that all the ribs (7), which are arranged between two adjacent tubes (2), are combined to form a substantially zig-zag-shaped corrugated or folded ribbed belt (6). Heat exchanger according to one of claims 1 to 9,
characterized in that the heat exchanger (1) is designed as a flat tube heat exchanger, wherein the extension direction of the tubes (2) transversely to the tube longitudinal direction (5) in the rib longitudinal direction (8) is greater than transverse thereto.

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