EP1530703B1 - Heat exchanger - Google Patents

Abstract

At one end (8) the several flat tubes (2) in the heat transmitter (1) are fed with fluid (F) via a manifold (6). The tubes fit positively into the manifold, each having a recess in the outside contour (10) of the tube which matches that of the manifold. The tube (1) end (9) has several openings (13) and the tube end contour (10) can be open, the tube fitted with outside stays and one tube at least has a center stay. The inside contour (12) of the tube (8) has an opening (14) and this end can be materially joined to the manifold. Preferred use is vehicle air conditioning.

Description

The invention relates to a heat exchanger with a number of mutually parallel and spaced apart flat tubes, in particular for an air conditioning system of a vehicle.

Conventionally, heat exchangers are currently used in vehicles which absorb heat from a fluid flowing through them on the primary side, e.g. Carbon dioxide, water or refrigerant, at a heat exchanger secondary side flowing air. Conversely, the fluid flowing through the heat exchanger can absorb heat from the air. For this purpose, the heat exchanger in particular parallel to each other and spaced apart flat tubes. For a sufficiently strong and above all against mechanical stresses stable arrangement of the heat exchanger ribs or reinforcing webs are arranged between the flat tubes.

For common feeding of the flat tubes with the fluid they are connected at the end with so-called collection boxes or manifolds. In this case, the formed as a coolant or refrigerant fluid flows through channels extending in the flat tubes and is then collected in the collection boxes or pipes and optionally deflected into adjacent flat tubes of the heat exchanger. For this purpose, the headers usually have partitions.

Such heat exchangers with penetrated by so-called capillaries or small channels flat tubes, which are fed via the collecting box are, for example, from EP 0 654 645 B1 and the JP-2001 280884 known.

The flat tubes have the advantage that very small channels, also called cooling or fluid channels, can be provided, which are particularly pressure-stable. As a result, the collecting box or collecting manifold performing a fluid collecting and / or fluid distributing function must be designed to be particularly bulky. In this case, the heat exchanger must withstand a particularly high internal pressure, but a so-called bursting pressure is well above a maximum allowable operating pressure. Therefore, care is taken in the design and construction of the heat exchanger with regard to its maximum allowable compressive strength that in particular the collection box or manifold has a sufficiently thick wall thickness. In particular, when using the heat exchanger for an air conditioning circuit with carbon dioxide or the so-called R 134 A fluid as the cooling medium, the heat exchanger and its collection box because of the usual high pressures very thick-walled headers or manifold with partially pronounced beads on. The disadvantage here is that in this way in the area of the collecting tank, due to the large thickness, a high material usage is given, which is particularly time-consuming in a soldering of the flat tubes with the collecting box. In addition, such a trained heat exchanger is particularly costly and limited in terms of design freedom, especially for the underlying collection box. Furthermore, such a trained heat exchanger has a particularly high weight.

The invention is therefore based on the object, a heat exchanger, in particular for an air conditioner of a vehicle to specify, which is particularly simple and has a low weight.

The object is achieved in a heat exchanger with a number of mutually parallel and spaced apart flat tubes, which via at least one end via a manifold be bespeisbar with a fluid, wherein the flat tubes are arranged at least partially positive fit in the manifold.

The invention is based on the consideration that a due to very different mechanical loads particularly thick-walled training of a collecting tank or a manifold for by a fluid, in particular cooling medium flow-through flat tubes of a heat exchanger should be dimensioned to the extent that they are particularly simple and lightweight. In addition, the opening in the manifold and held flat tubes should at the same time allow stiffening of the manifold, so this is additionally formed pressure-resistant or pressure-resistant on the design or molding of the ends of the flat tubes. For this purpose, the flat tubes in the manifold are preferably arranged at least partially positively. In particular, the flat tubes are largely completely guided in the manifold, so that they can record a positive connection, in particular a tensile and / or compressive force in addition to a positive connection.

For the most complete form fit of the flat tubes in the manifold in their support a representing the end of the respective flat tube outer contour is at least partially adapted to a manifold representing the inner contour. By virtue of such an arrangement of the flat tubes in the manifold used over the entire circumference of the collecting tank or tube, the flat tubes are arranged in the manner of a tensile and / or composite anchor in the heat exchanger.

In an alternative embodiment of the heat exchanger, in particular its flat tubes, preferably an outer contour representing the end of the respective flat tube is at least partially adapted to an outer contour representing the manifold. As an alternative to the outer contour of the flat tube adapted to the inner contour of the manifold, the respective flat tube can be inserted from the outside into the heat exchanger and thus be mounted when the at least one end of one of the flat tubes is adapted to the outer contour of the manifold. For this purpose, the collection manifold is expediently with at least one recess provided for performing one of the flat tubes. The recess is designed to receive the flat tube in particular as a slot-like recess. Appropriately, the end of the respective flat tube is held cohesively to the recess of the manifold. For example, the end of the flat tube is compressed or crushed and soldered together in the recess of the manifold with this. By such a Zulötung from the outside of the flat tubes with the manifold manifold a sufficiently good tightness of the heat exchanger with respect. Of this flowing fluid is ensured so that a humidification of the heat exchanger secondary air flowing through the air is reliably avoided.

To increase the rigidity and compressive strength of the heat exchanger, one end of at least one of the flat tubes is provided with outside webs. As an alternative to such a semi-profile-like design of the flat tube end, the flat tube can serve as a complete circumferential stiffening and support of the manifold or manifold end. For this purpose, the end of the relevant flat tube is provided with an opening or recess. Such a frame-like design of the end of the respective flat tube by a peripheral frame or a circumferential profile or by a half-frame or half-profile in the form of webs is depending on the use of the heat exchanger, a corresponding stiffening or compressive strength of the heat exchanger adjustable. In the manufacture of such flat tubes provided with an opening or flat tubes having such outward webs, the opening or the webs is formed by punching, punching or water jet method. At the same time, the perforated opening or the opening formed by the webs serves for supplying the fluid, in particular for the passage of coolant or refrigerant, into the capillaries or channels of the flat tube which are exposed through the opening. In this case, the bores or capillaries extending in the respective flat tube are fed via the fluid guided in the opening of the flat tube end. In other words: Such a ring-shaped (= punched-out opening) or U-shaped end (= laterally punched webs) of the flat tubes, which by means of the respective end completely positive or at least partially positively in the Collective manifolds are arranged, in each case forms in each case a part of a collection or distribution channel of the manifold for feeding and / or removal of the fluid. In a further alternative embodiment, the end of at least one of the flat tubes is provided with a further centrally arranged web. Depending on the degree of introduction of the flat tube in the manifold manifold can be formed by a two outer and a central web exhibiting end of the flat tube at its complete introduction and thus the complete positive connection with the manifold in a particularly simple manner a two-part manifold, with a through the two-part formed chamber for supplying the fluid and the other chamber for discharging the fluid can be used. Alternatively, in the case of like-minded feeding of the chambers of such a shared collection manifold, a plurality of flat tubes combined into a group can be fed separately, whereby different types of flow through the heat exchanger are made possible.

For a largely accurate positioning of the flat tubes in the manifold, the end of the respective flat tube is at least partially guided in a recess extending in the inner contour recess. For example, the manifold has on the inside a channel-shaped bead or a groove in which the end of the respective flat tube is guided and inserted. As a result, in addition to a particularly flush and positive arrangement of the flat tubes in the manifold manifold also a sufficiently good fixation of the flat tubes is possible.

For a pressure and / or tension stable arrangement of the flat tube in the manifold the end of the respective flat tube is cohesively held on the manifold. For example, while the end of the respective flat tube with or without filler material is held on the manifold. The end of the flat tube is soldered along the recess of the manifold.

For a differentiated feeding of the heat exchanger with the fluid, e.g. in cross-countercurrent or crosscurrent, the collection manifold is divided longitudinally into at least two regions. Preferably, the collection box or manifold is split two or more times. For this purpose, depending on the type and design of the heat exchanger, a partition wall is arranged in the manifold. The end of at least one of the flat tubes is provided with a slot for receiving the partition. For a variable adjustment of the fluid flowing through the heat exchanger, the partition expediently has a passage opening. In a particularly simple and cost-effective design of the heat exchanger for different flow modes, the ends of the flat tubes are formed differently. For example, a number of flat tubes, which are arranged adjacent to each other, provided at least at one end with the annular and / or U-shaped passage opening for the fluid, wherein a next flat tube end is formed as a solid profile and thus not punched through, so that this assumes the function of a partition. As a result, the introduction of additional partitions can be omitted. This makes it possible, again compared with the prior art lighter training of the heat exchanger.

Depending on the type and design of the heat exchanger, the flat tubes can end up in each case an associated manifold distribution. In this case, the flat tubes can be fed on one side and / or on both sides, ie in a one-sided feeding of the flat tubes, for example, a two-part manifold with a chamber for supply and a further chamber for discharging the fluid is arranged on one end of the flat tubes. In the case of a two-sided feeding of the flat tubes, a single manifold distributor is provided on each side for feeding on the one side and for discharging the fluid on the other side. Alternatively or additionally, in the case of a U-shaped flow through the fluid through the heat exchanger, one of the manifolds serves as an inlet and outlet and the opposite manifold as a deflection channel for deflecting the fluid between two adjacent flat tubes. Preferably, the end arranged on the flat tubes manifold manifold uniformly formed. This ensures a sufficiently good and uniform flow through the flat tubes with the fluid.

The advantages achieved by the invention are in particular that is formed by a positive arrangement of the flat tubes in the manifold or manifold, in particular by a complete positive engagement in the circumferential direction of the manifold this with significantly lower wall thicknesses. By such a positive arrangement of the flat tubes in the manifold manifold acting on the heat exchanger tensile and / or compressive forces in the manner of a tensile or composite anchor in the flat tubes are derived. Furthermore, such flat tubes inserted into the manifold manifold for abutment or flushing are particularly easy to assemble and easy to handle. By soldering each of an open (= annular) or semi-open (= u-shaped) or closed end having flat tubes on the inner contour and / or outer contour of the manifold an additional stiffening of the manifold and thus the heat exchanger in the form of stiffening ribs is given. Furthermore, can be omitted by 'such form and / or cohesively arranged flat tubes additional partitions for deflecting the refrigerant or refrigerant, as by the variously shaped end flat tubes with and / or without opening or recess this even partitions for deflecting the refrigerant or refrigerant form. As a result, in addition to the particularly lightweight design of the heat exchanger and the cost of. The required material usage are significantly reduced.

Figuren 1A - 1C

schematisch einen Wärmeübertrager mit einer Mehrzahl von formschlüssig in einem Sammelverteiler angeordneten Flachrohren,

Figur 2

schematisch einen Wärmeübertrager mit einem geteilten Sammelkasten,

Figuren 3A - 3C

schematisch einen Wärmeübertrager mit endseitig mit Stegen versehenen Flachrohren,

Figur 4

schematisch einen Wärmeübertrager nach den Figuren 3A - 3C in perspektivischer Darstellung,

Figuren 5A - 5B

sowie 6A - 6B schematisch verschiedene Wärmeübertrager mit verschiedene Querschnittsformen aufweisenden Sammelverteilern,

Figuren 7A - 7B

schematisch einen Wärmeübertrager mit von außen eingeführten Flachrohren,

Figuren 8A - 8B

schematisch einen Wärmeübertrager mit zwei Öffnungen aufweisenden Flachrohren,

Figur 9

schematisch einen erfindungsgemäßen Wärmeübertrager mit einer für verschiedene Durchströmungen vorgesehenen Trennwand im Sammelverteiler, und

Figur 10

schematisch einen Wärmeübertrager mit zwei endseitig der Flachrohre angeordneten Sammelverteilern.

Embodiments will be explained in more detail with reference to a drawing. Show:

Figures 1A - 1C

1 schematically a heat exchanger with a plurality of form-fittingly arranged in a manifold distributor flat tubes,

FIG. 2

schematically a heat exchanger with a shared collection box,

FIGS. 3A-3C

schematically a heat exchanger with end provided with webs flat tubes,

FIG. 4

1 schematically shows a heat exchanger according to FIGS. 3A-3C in a perspective view;

FIGS. 5A-5B

6A-6B schematically different heat exchangers with manifolds having different cross-sectional shapes,

FIGS. 7A-7B

schematically a heat exchanger with externally inserted flat tubes,

Figures 8A-8B

schematically a heat exchanger with two openings having flat tubes,

FIG. 9

schematically a heat exchanger according to the invention with a provided for different flows partition in the manifold, and

FIG. 10

schematically a heat exchanger with two end of the flat tubes arranged manifolds.

Corresponding parts are provided in all figures with the same reference numerals.

Figures 1A to 1C show a heat exchanger assembly 1 with a number of mutually parallel and spaced apart flat tubes 2. The flat tubes 2 are provided with fluid channels 4 for flow through this with a fluid F, for. B. a coolant or refrigerant flow for an air conditioning system of a vehicle provided. The fluid channels 4 have a particularly small diameter and are designed in the manner of capillaries. To feed the fluid channels 4 of the respective flat tubes 2, these are bespeisbar via a manifold 6 with the fluid F. For a heat exchanger 1 as simple as possible and having a particularly low weight, the flat tubes 2 are arranged in the manifold 6 at least partially positively. For this purpose, the end 8 of the respective flat tube 2 and an outer contour 10 representing this end 8 are adapted to an inner contour 12 representing the manifold 6.

For a particularly thin-walled and thus material-saving design of the manifold 6, the end 8 of at least one of the flat tubes 2 is provided with an opening 13 (Figure 1 B). Such a frame-like, e.g. annular formation of the flat tube end 8 allows for complete positive engagement of the outer contour 10 with the inner contour 12 of the manifold 6 a this against mechanical stresses sufficiently good protection by the manifold 6 largely completely enclosing stiffening and support. This leads to a particularly thin-walled design of the manifold 6. The introduced at the end 8 of the respective flat tube 2 opening 13 serves itself as a flow channel of the manifold 6 for supplying and / or discharging the fluid F. Depending on the nature and design of the flat tubes. 2 For example, the opening 13 may be made by punching, punching, drilling or other suitable means. For example, already joined together and a component of the heat exchanger 1 forming flat tubes 2, which are similar in terms of the opening 13, the opening 13 can be introduced in a single process step by punching or punching. Alternatively, in the case of variously through-flowable flat tubes 2 of a single heat exchanger 1, which are configured differently at the ends, i. with and / or without opening 13, the flat tubes 2 can be made separately or in groups.

Figure 2 shows an alternative heat exchanger 1 with a flat tube 2, the end 8 is adapted with its outer contour 10 to the inner contour 12 of the manifold 6. For secure positioning, the end 8 of the respective flat tube 2 is guided at least partially in a recess 14 of the manifold 6 extending in the inner contour 12. Depending on the type and formation of the recess 14 may be formed as a groove-shaped bead or groove. In this case, the recess 14 extend partially or completely along the inner contour 12 of the manifold 6. That is, the recess 14 can rotate around the entire inner contour 12 of the manifold 6, wherein the recess 14 is formed only in the region of the supply of the flat tube 2 as an opening. In the region of the fixation of the flat tube 2 on the manifold 6, the recess 14 is designed as a bead or groove.

The end 8 of the respective flat tube 2 is inserted for mounting in the heat exchanger 1 through the recess 14 and held in a form-fitting manner in the manifold 6. For a particularly good adhesion of the holder of the flat tube 2 in the manifold 6, the end 8 of the respective flat tube 2 is held cohesively on the manifold 6. For this purpose, the end 8 of the respective flat tube 2 is preferably soldered along the recess 14 of the manifold 6. Alternatively, the end 8 can be glued or welded. As shown in Figure 2, the manifold 6 is here divided into two areas 16 which extend transversely to the air flow direction L. Such a two-part manifold 6, also called two-part collection box, allows a differentiated and separate supply of individual flat tubes 2. For a particularly pressure-resistant and stable arrangement of the heat exchanger 1, a rib 18 is disposed between the spaced apart flat tubes 2.

FIGS. 3A to 3C show an alternative embodiment for the heat exchanger 1. In this case, the end 8 of the respective flat tube 2 is provided with outside webs 20 which are sufficient for good strength and rigidity in a heat exchanger 1 designed for low pressure. Depending on the type and design of the webs 20, the latter representing this opening 13 of the end 8 of the respective flat tube 2 can also be prepared by punching or punching. In this case, the flat tube 2 in the region of the webs 20 is positively connected to the manifold 6. In FIG. 4, the heat exchanger 1 according to FIGS. 3A to 3C is shown in a perspective view, this heat exchanger 1 having only a simple manifold 6.

FIGS. 5A to 5B and FIGS. 6A to 6B show different cross-sectional shapes for the manifold 6 and, as a result, the opening 13 provided in the end 8 of the respective flat tube 2. In FIGS. 5A to 5B, the manifold 6 has, for example. B. a round cross-sectional shape. In FIGS. 6A and 6B, the manifold 6 is formed as a rectangle or square with respect to its cross section.

FIGS. 7A and 7B show an alternative embodiment for the heat exchanger 1. In this case, the end 8 of the respective flat tube 2, in particular its outer contour 10, is at least partially adapted to an outer contour 22 representing the manifold 6. In this case, the flat tube 2 is introduced via an externally supplied recess 24 of the manifold 6 and / or on the opening in the direction of the flat tubes 2 recess 14 of the manifold 6, wherein the flat tube 2 during assembly in the heat exchanger 1 with its end 8 via the surface of the manifold 6 protrudes. The collective distributor 6 superior end 8 of the flat tube 2 is then compressed and / or soldered to the outer contour 22 of the manifold 6.

FIGS. 8A and 8B show an alternative embodiment of the heat exchanger 1. In this case, the manifold 6 is formed in one piece. The end 8 of the respective flat tube 2 is provided for a differentiated flow of the fluid channels 4 with a split opening 13. This split opening 13 is effected in a manufacturing step, for example by punching holes in the end 8 of the respective flat tube 2. By such a profile or frame-like design of the end 8 of the respective flat tube 2 causes this in the positive arrangement in the manifold 6 an additional stiffening of the manifold 6. In addition, through the openings 13 itself a manifold 6 continuous flow channel 36 is formed. In this case, both openings 13 are similar - flow - with the same sense. Alternatively, one of the opening 13 for supplying the fluid F and the other opening 13 for discharging the fluid F may be used.

Figure 9 shows an embodiment of the invention for a heat exchanger 1 with a rectangularly formed manifold 6, in which a plurality of uniform ends 8 having flat tubes 2 are held positively and / or cohesively. For a flow through the channels 4 of adjacent flat tubes 2 in the countercurrent principle of the manifold 6 is divided by means of a partition 26 longitudinally and transversely in areas 16 a to 16 d. Here, the manifold 6 is performed by dividing into the areas 16a to 16d as a four-part manifold 6, so that a resulting heat exchanger 1 only one arranged at one end 8 of the flat tubes 2 manifold 6 for supplying and discharging the fluid F has.

The manifold 6 comprises an inlet channel 28 and an outlet channel 30 for supplying and discharging the fluid F into regions 16a to 16d separated from each other by the partition wall 26 in which the openings 13 of the respective flat tubes 2 arranged therein serve as a flow channel 36. Due to the introduction of the partition wall 26 and the resulting subdivision into longitudinally extending regions 16a, 16c and 16b, 16d, the channels 4 arranged within a single flat tube 2 are likewise flowed through in countercurrent from the fluid F. Due to the transversely extending subdivision of the manifold 6 in the areas 16 a, 16 b and 16 c, 16 d adjacent flat tubes 2 are flowed through in a countercurrent flow principle. For a like-minded flow through the channels 4 of a single flat tube 2, the partition wall 26 comprises at least one passage opening 32nd

For receiving the partition wall 26 in the manifold 6, the respective flat tube 2 is provided with a slot 34. The slot 34 serves both the leadership of the partition 26 and the attachment of this, for example by soldering or gluing. Depending on the type and design of the heat exchanger 1, in particular the configuration of the partition wall 26 with and / or without passage openings 32 or subdivisions, the flat tubes 2 can be flowed differently, for example in cross countercurrent, in the cross dc, in countercurrent and / or in direct current.

Figure 10 shows a further alternative embodiment of a heat exchanger 1, the flat tubes 2 are flowed through with different sense of direction. In this case, the partition wall 26 can be omitted according to Figure 9 by the flat tubes 2 serve by a correspondingly different formation of the respective ends 8 itself as a partition. For this purpose, a plurality of flat tubes 2a end provided with openings 13 for the flow through this with the fluid F. In contrast, a flat tube 2b serving as a partition has a closed end 8. In addition, the flat tubes 2 open with their ends 8 in each case into a manifold 6 a and 6 b, wherein the lower manifold 6 b only the deflection of the fluid F of countercurrently flowed through flat tubes 2 a and 2 b is used. The upper manifold 6a serves both the supply and the discharge of the fluid F via a single formed as an input channel 28 and output channel 30 and formed through the openings 13 of the respective flat tubes 2 flow channel 36, the fluid F seen in the longitudinal direction of the U-shaped Heat exchanger 1 flows through.

LIST OF REFERENCE NUMBERS

1

Heat exchanger

2, 2a, 2b

flat tubes

4

fluid channels

6

collection manifold

8th

respective end of a flat tube 2

10

Outer contour of the flat tube 2

12

Inner contour of the manifold 6

13

opening

14

recess

16a to 16d

two areas of the manifold 6

18

rib

20

outside bars

22

Outer contour of the manifold 6

24

recess

26

partition wall

28

input channel

30

output channel

32

Through opening

34

slot

36

flow channel

F

fluid

L

Air flow direction

Claims (11)

1. Heat exchanger (1) with a number of flat tubes (2) arranged parallel to and at a distance from one another and supplied at least at one end (8) with a fluid (F) via a header (6), wherein the flat tubes (2) are at least partially located positively in the header (6), wherein an external contour (10) or an internal contour (12) representing the end (8) of each flat tube (2) is at least partially matched to an external contour (22) representing the header (6) and wherein the end (8) of each flat tube (2) is at least partially guided in a recess (14) in the internal contour (12), wherein the end (8) of each flat tube (2) is retained on the header (6) by adhesive force and wherein the end (8) of each flat tube (2) is soldered along the recess (14) of the header (6) and wherein the header (6) is provided with at least one cut-out (24) or recess (14) for the passage of one of the flat tubes (2), characterised in that the header (6) is divided in the longitudinal direction into at least two areas (16) by means of a partition (26), and in that the end (8) of at least one of the flat tubes (2) has a slot (34) designed to accommodate the partition (26) in the contact area with the external contour.
2. Heat exchanger according to claim 1, wherein the end (8) of at least one of the flat tubes (2) is provided with one or more openings (13).
3. Heat exchanger according to claim 1 or 2, wherein the end (8) of at least one of the flat tubes (2) has an open contour or an opening.
4. Heat exchanger according to any of claims 1 to 3, wherein the end (8) of at least one of the flat tubes (2) is provided with external webs (20).
5. Heat exchanger according to any of claims 1 to 4, wherein the end (8) of the flat tube (2) is retained on the cut-out (24) of the header (6) by adhesive force.
6. Heat exchanger according to any of claims 1 to 5, wherein the partition (26) has a through opening (32).
7. Heat exchanger according to any of claims 1 to 6, wherein each flat tube (2) terminates in an associated header at the end.
8. Heat exchanger according to claim 7, wherein the headers (6) located at the ends of the flat tubes (8) have a uniform design.
9. Heat exchanger according to any of claims 1 to 8, wherein the flat tubes (2) positively located in the header (6) have ends (8) of different designs.
10. Heat exchanger according to any of claims 1 to 9, wherein at least one of the flat tubes (2) positively located in the header (6) is closed and acts as a partition.
11. Air conditioning system for a vehicle with a heat exchanger (1) according to any of claims 1 to 10.

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