EP1530703A1

EP1530703A1 - Heat exchanger

Info

Publication number: EP1530703A1
Application number: EP03747885A
Authority: EP
Inventors: Peter Geskes; Christoph Walter; Karl-Heinz Staffa
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2002-08-13
Filing date: 2003-08-07
Publication date: 2005-05-18
Anticipated expiration: 2023-08-07
Also published as: DE50308809D1; ATE380994T1; DE10237648A1; AU2003266971A1; EP1530703B1; WO2004023056A1; US20050236149A1

Abstract

The aim of the invention is to provide a light and especially simple heat exchanger comprising a number of parallel, interspaced flat tubes. To this end, the flat tubes (2) can be supplied with a fluid (F) via at least one end (8) by means of a manifold (6), said flat tubes (2) being arranged in the manifold (6) in an at least partially positively locking manner.

Description

Heat exchanger

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

Heat exchangers are usually used in vehicles today, which heat from a fluid flowing through this primary side, e.g. Release carbon dioxide, water or refrigerant into air flowing through the heat exchanger on the secondary side. Conversely, the fluid flowing through the heat exchanger can absorb heat from the air. For this purpose, the heat exchanger has, in particular, parallel flat tubes spaced apart from one another. For a sufficiently firm and above all stable mechanical arrangement of the heat exchanger, ribs or reinforcing webs are arranged between the flat tubes.

To feed the flat tubes together with the fluid, they are connected at the end to so-called header boxes or header distributors. The fluid designed as a coolant or refrigerant flows through channels running in the flat tubes and is then collected in the collecting boxes or tubes and, if necessary, deflected into adjacent flat tubes of the heat exchanger. For this purpose, the collecting boxes usually have partitions. Such a heat exchanger with flat tubes penetrated by so-called capillaries or small channels and which are fed via the collecting tank is known for example from EP 0 654 645 B1.

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 collection box or distribution manifold, which performs a fluid collection and / or fluid distribution function, has to be of particularly large volume. The heat exchanger must withstand a particularly high internal pressure, but a so-called burst pressure is clearly above a maximum permissible operating pressure. Therefore, when designing and designing the heat exchanger with regard to its maximum permissible compressive strength, care is taken to ensure that, in particular, the header box or the header pipe has a sufficiently thick wall. Particularly when the heat exchanger is used 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 header tank have very thick-walled header pipes or header manifolds with partially pronounced beads due to the high pressures that are usual here. The disadvantage here is that this results in the area of

Collection box, due to the large thick walls, a high amount of material is given, which is particularly time consuming when soldering the flat tubes to the collection box. In addition, a heat exchanger designed in this way is particularly cost-intensive and in terms of. the freedom of design, especially for the underlying collection box. Furthermore, a heat exchanger designed in this way has a particularly high weight.

The invention is therefore based on the object of specifying a heat exchanger, in particular for an air conditioning system of a vehicle, which is of particularly simple design and has a low weight.

The object is achieved according to the invention in a heat exchanger with a number of flat tubes which are arranged parallel to one another and spaced apart from one another and which have at least one end via a collecting tube. mel distributor can be supplied with a fluid, the flat tubes in the manifold being arranged at least partially in a form-fitting manner.

The invention is based on the consideration that a particularly thick-walled design of a header tank or header manifold for flat tubes of a heat exchanger through which a fluid, in particular cooling medium can flow, should be dimensioned in such a way that they are particularly simple and light in design. In addition, the flat tubes ending in the manifold and held there should at the same time enable the manifold to be stiffened, so that the latter is additionally designed to be pressure-resistant or pressure-stable via the design or shape 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 in addition to a form fit, they can also absorb a force fit, in particular a tensile and / or compressive force.

For the most complete possible form fit of the flat tubes in the manifold when they are held, an outer contour representing the end of the respective flat tube is at least partially adapted to an inner contour representing the manifold. Such an arrangement of the flat tubes in the manifold, which takes advantage of the entire circumference of the header box or tube, means that the flat tubes are arranged in the manner of a tension and / or composite anchor in the heat exchanger.

In an alternative embodiment of the heat exchanger, in particular its flat tubes, an outer contour representing the end of the respective flat tube is preferably 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, when at least one end of one of the flat tubes is adapted to the outer contour of the manifold, the respective flat tube can be inserted into the heat exchanger from the outside and thus be mounted. For this purpose, the manifold with at least one recess is expedient provided for the passage of one of the flat tubes. The recess is designed to receive the flat tube in particular as a slot-like recess. The end of the flat tube in question is expediently held in a cohesive manner at the recess of the manifold. For example, the end of the flat tube is compressed or crimped and soldered together in the recess of the manifold. Such soldering from the outside of the flat tubes to the manifold ensures that the heat exchanger is sufficiently well sealed with respect to the fluid flowing through it, so that humidification of the air flowing through the heat exchanger on the secondary side is reliably avoided.

To increase the rigidity and pressure resistance of the heat exchanger, one end of at least one of the flat tubes is provided with webs on the outside. As an alternative to such a semi-profile-like configuration of the flat tube end, the flat tube can serve at the end as a completely circumferential reinforcement and support of the manifold or manifold. For this purpose, the end of the flat tube in question 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 peripheral profile or by a half-frame or half-profile in the form of webs, depending on the use of the heat exchanger, a corresponding stiffening or pressure resistance of the heat exchanger can be set. When producing such flat tubes provided with an opening or such flat tubes having external webs, the opening or the webs are formed by punching, punching or water jet methods. 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 exposed through the opening. Here, the bores or capillaries running in the respective flat tube are fed via the fluid guided in the opening of the flat tube end. In other words: Such an annular (= punched-out opening) or U-shaped end (= laterally punched-out webs) of the flat tubes, which by means of the respective end are completely positive or at least partially positive in the Collective distributors are arranged, each itself forms part of a collecting or distribution channel of the collective distributor for feeding and / or discharging the fluid. In a further alternative embodiment, the end of at least one of the flat tubes is centered with _another, provided arranged web. Depending on the degree of insertion of the flat tube into the manifold, a two-part manifold can be formed in a particularly simple manner by an end of the flat tube that has two outer and a central web when it is fully inserted and thus fully form-fit with the manifold, one by the split formed chamber can be used to supply the fluid and the other chamber can be used to discharge the fluid. As an alternative, if the chambers of a collecting distributor divided in this way are fed in the same way, a plurality of flat tubes combined into a group can be fed separately from one another, as a result of which different types of flow through the heat exchanger are made possible.

For a largely precise positioning of the flat tubes in the manifold, the end of the respective flat tube is preferably at least partially guided in a recess running in the inner contour. For example, the inside of the manifold has a channel-shaped bead or a groove in which the end of the respective flat tube is guided and inserted. In addition to a particularly flush and form-fitting arrangement of the flat tubes in the manifold, this also enables a sufficiently good fixing of the flat tubes.

For a pressure- and / or tensile-stable arrangement of the flat tube in the manifold, the end of the respective flat tube is expediently held integrally on the manifold. For example, the end of the respective flat tube is held on the manifold with or without filler material. In a preferred embodiment, the end of the flat tube is soldered along the recess of the manifold. Alternatively or additionally, the end of the respective flat tube can be glued or welded. For a differentiated feeding of the heat exchanger with the fluid, for example in countercurrent or crosscurrent, the manifold is expediently divided into at least two areas along and / or across. The collecting box or collecting distributor is preferably divided two or more times. Depending on the type and design of the heat exchanger, a partition is arranged in the manifold for this purpose. The end of at least one of the flat tubes is expediently provided with a slot for receiving the partition. For a variable setting of the fluid flowing through the heat exchanger, the partition wall expediently has a passage opening. In a particularly simple and inexpensive design of the heat exchanger for different types of flow, the ends of the flat tubes are designed differently. For example, a number of flat tubes, which are arranged adjacent to one another, are provided at least at one end with the annular and / or U-shaped passage opening for the fluid, a next flat tube being designed at the end as a solid profile and thus not punched through, so that this acts as a partition. This eliminates the need for additional partition walls. This enables the heat exchanger to be made even lighter than in the prior art.

Depending on the type and design of the heat exchanger, the flat tubes can end at the end in an associated manifold. The flat tubes can be fed on one side and / or on both sides, that is to say when the flat tubes are fed on one side, for example a two-part manifold with a chamber for supplying and a further chamber for discharging the fluid is arranged on one end of the flat tubes. When the flat tubes are fed on both sides, a single manifold is provided on the end for feeding and on the other for discharging the fluid. Alternatively or additionally, when the fluid flows through the heat exchanger in a U-shape, one of the manifolds can serve as a feed and discharge and the opposite manifold can serve as a deflection channel for deflecting the fluid between two adjacent flat tubes. The manifolds arranged at the end of the flat tubes are preferred uniformly trained. This ensures a sufficiently good and uniform flow of fluid through the flat tubes.

The advantages achieved by the invention are, in particular, that the form of a flat arrangement of the flat tubes in the manifold or manifold, in particular by a complete positive connection in the circumferential direction of the manifold, is designed with significantly smaller wall thicknesses. Such a form-fitting arrangement of the flat tubes in the manifold dissipates tensile and / or compressive forces acting on the heat exchanger in the manner of a tension or composite anchor in the flat tubes. Furthermore, such flat tubes inserted into the manifold at a stop or flush are particularly simple to install and easy to handle. By soldering the open (= ring-shaped) or semi-open (= u-shaped) or closed end of the flat tubes to the inner contour and / or outer contour of the manifold, additional stiffening of the manifold and thus of the heat exchanger is provided in the manner of stiffening ribs. Additional partition walls for deflecting the coolant or refrigerant can Furthermore, the through ^"such positive and / or materially arranged flat tubes omitted, since by the different end formed flat tubes with and / or without opening or recess these self partition walls for deflecting the coolant or refrigerant As a result, in addition to the particularly light design of the heat exchanger, the costs in terms of the material used are also significantly reduced.

Embodiments of the invention are explained in more detail with reference to a drawing. In it show:

FIGS. 1A-1C schematically show a heat exchanger with a plurality of flat tubes arranged in a form-fitting manner in a manifold,

2 schematically shows a heat exchanger having a divided ^"■ collecting box, FIGS. 3A-3C schematically show a heat exchanger with flat tubes provided at the ends with webs,

FIG. 4 schematically shows a heat exchanger according to FIGS. 3A-3C in a perspective view,

FIGS. 5A-5B and 6A-6B schematically show different heat exchangers with manifolds having different cross-sectional shapes,

FIGS. 7A-7B schematically show a heat exchanger with flat tubes inserted from the outside,

FIGS. 8A-8B schematically show a heat exchanger with two openings with flat tubes,

FIG. 9 schematically shows a heat exchanger with a dividing wall in the manifold intended for different flows, and

Figure 10 schematically shows a heat exchanger with two manifolds arranged at the ends of the flat tubes.

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

FIGS. 1A to 1C show a heat exchanger arrangement 1 with a number of flat tubes 2 arranged parallel to one another and spaced apart from one another. The flat tubes 2 are provided with fluid channels 4 for the flow through them with a fluid F, for. B. a coolant or refrigerant flow for an air conditioning system of a vehicle. 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 can be fed with the fluid F via a manifold 6. For A heat exchanger 1 which is as simple as possible and has a particularly low weight, the flat tubes 2 in the manifold 6 are at least partially positively arranged. 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 (FIG. 1B). Such a frame-like, e.g. ring-shaped design of the flat tube end 8 enables the outer contour 10 with the inner contour 12 of the manifold 6 to be sufficiently positively protected against mechanical stresses by a stiffening and support that largely completely surrounds the manifold 6. This leads to a particularly thin-walled design of the manifold 6. The opening 13 introduced at the end 8 of the flat tube 2 in question serves itself as a flow channel of the manifold 6 for supplying and / or discharging the fluid F. Depending on the type and design of the flat tubes 2 For example, the opening 13 can be made by punching, punching, drilling or any other suitable type. For example, in the case of flat tubes 2 which have already been joined together and form a component of the heat exchanger 1 and which are of identical design with regard to the opening 13, the opening 13 can be introduced in a single method step by punching out or punching. Alternatively, in the case of flat tubes 2 of a single heat exchanger 1 which can be flowed through in different ways and which are designed differently at the ends, i.e. with and / or without opening 13, the flat tubes 2 can be produced 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 at least partially guided in a recess 14 of the manifold 6 running in the inner contour 12. Depending on the type and formation of the recess 14, this can be designed as a channel-shaped bead or groove. The recess 14 can run partially or completely along the inner contour 12 of the manifold 6. That is, the recess 14 can run around the entire inner contour 12 of the manifold 6, the recess 14 being designed as an opening only in the region of the feed of the flat tube 2. In the area of fixing the flat tube 2 to the manifold 6, the recess 14 is designed as a bead or groove.

The end 8 of the respective flat tube 2 is for assembly in the

Heat exchanger 1 inserted through the recess 14 and held positively in the manifold 6. For a particularly good adhesion of the mounting of the flat tube 2 in the manifold 6, the end 8 of the respective flat tube 2 is held integrally 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 collection manifold 6 here in two regions 16 is divided, which transversely ng to Luftströmungsrichtu ^'extend L. Such a two-part manifold 6, also called a two-part collecting box, enables differentiated and separate feeding of the individual flat tubes 2. For a particularly pressure-resistant and stable arrangement of the heat exchanger 1, a rib 18 is arranged between the spaced apart flat tubes 2.

Figures 3A to 3C show an alternative embodiment for the

Heat exchanger 1. 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 a low pressure. Depending on the type and design of the webs 20, the opening 13 of the end 8 of the flat tube 2 in question, which represents this, can also be produced by punching or punching. The flat tube 2 is positively connected to the manifold 6 in the area of the webs 20. FIG. 4 shows a perspective view of the heat exchanger 1 according to FIGS. 3A to 3C, this heat exchanger 1 having only a simple manifold 6. FIGS. 5A to 5B and 6A to 6B show different cross-sectional shapes for the manifold 6 and, as a result, for the opening 13 provided in the end 8 of the respective flat tube 2. In FIGS. 5A to 5B, the manifold 6 has z. B. a round cross-sectional shape. In FIGS. 6A and 6B, the cross-section of the manifold 6 is designed as a rectangle or square.

FIGS. 7A and 7B show an alternative embodiment for the heat exchanger 1. 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. The flat tube 2 is inserted into this from an externally accessible recess 24 of the collecting distributor 6 and / or via the opening 14 of the collecting distributor 6 opening in the direction of the flat tubes 2, the end of the flat tube 2 during assembly in the heat exchanger 1 being 8 the surface of the manifold 6 protrudes. The end 8 of the flat tube 2 projecting beyond the manifold 6 is then compressed and / or soldered to the outer contour 22 of the manifold 6.

Figures 8A and 8B show an alternative embodiment for the heat exchanger 1. The manifold 6 is formed in one piece. The end 8 of the respective flat tube 2 is provided with a divided opening 13 for a differentiated flow through the fluid channels 4. This divided opening 13 is brought about in one production 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, this causes an additional stiffening of the form-fitting arrangement in the manifold 6

Collective distributor 6. In addition, a flow channel 36 passing through the collective distributor 6 is formed by the openings 13 itself. Both openings 13 can be flowed through in the same way - 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 can be used. FIG. 9 shows a possible embodiment for a heat exchanger 1 with a rectangular manifold 6, in which a plurality of flat tubes 2 having uniform ends 8 are held in a form-fitting and / or integral manner. For a flow through the channels 4 of adjacent flat tubes 2 in the counterflow principle, the manifold 6 is divided longitudinally and transversely into areas 16a to 16d by means of a partition wall 26. Here, the manifold 6 is designed as a four-part manifold 6 due to the subdivision into the areas 16a to 16d, so that a heat exchanger 1 resulting therefrom has only one manifold 6 arranged at one end 8 of the flat tubes 2 for supplying and discharging the fluid F.

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 which are separated from one another by the partition wall 26 and in which the openings 13 of the relevant flat tubes 2 arranged therein serve as flow channels 36. Due to the introduction of the partition wall 26 and the resulting subdivision into regions 16a, 16c and 16b, 16d running in the longitudinal direction, the channels 4 arranged within a single flat tube 2 are likewise flowed through in countercurrent by the fluid F. Due to the subdivision of the manifold 6 into the areas 16a, 16b and 16c, 16d, adjacent flat tubes 2 are flowed through in the counterflow principle. For a like-minded flow through the channels 4 of an individual flat tube 2, the partition wall 26 comprises at least one passage opening 32.

To accommodate the partition 26 in the manifold 6, the respective flat tube 2 is provided with a slot 34. The slot 34 serves both to guide the partition 26 and to secure it, e.g. by

Solder or glue. Depending on the type and design of the heat exchanger 1, in particular the design of the partition wall 26 with and / or without through openings 32 or subdivisions, the flat tubes 2 can be flowed through differently, for example in cross-countercurrent, in cross-countercurrent, in countercurrent and / or in cocurrent. Figure 10 shows a further alternative embodiment for a heat exchanger 1, the flat tubes 2 are flowed through in different directions. The dividing wall 26 according to FIG. 9 can be omitted in that the flat tubes 2 themselves serve as dividing walls due to a correspondingly different design of the relevant ends 8. For this purpose, several flat tubes 2a are provided at the ends with openings 13 for the fluid F to flow through. In contrast, a flat tube 2b serving as a partition has a closed end 8. In addition, the ends of the flat tubes 2 each end 8 in one

Collective distributors 6a and 6b, the lower collective distributor 6b only serving to deflect the fluid F from flat tubes 2a and 2b through which countercurrent flows. The upper manifold 6a serves both the supply and the discharge of the fluid F via a single flow channel 36, which is designed as an inlet channel 28 and an outlet channel 30 and is formed through the openings 13 of the respective flat tubes 2, the fluid F being U-shaped in the longitudinal direction Flows through heat exchanger 1.

LIST OF REFERENCE NUMBERS

1 heat exchanger

2, 2a, 2b flat tubes

4 fluid channels

6 collective distributors

8 respective end of a flat tube 2

10 outer contour of the flat tube 2

12 Inner contour of the collective distributor 6

13 opening

14 recess

16a to 16d two areas of the collective distributor 6

18 rib

20 outside webs

22 outer contour of the manifold 6

24 recess

26 partition

28 input channel

30 output channel

32 passage opening

34 slot

36 flow channel

F fluid

L direction of air flow

Claims

P a t e n t a n s r u c h e

1. Heat exchanger (1) with a number of parallel and spaced flat tubes (2) which can be supplied with a fluid (F) via at least one end (8) via a manifold (6), the flat tubes (2 ) are arranged at least partially in a form-fitting manner in the manifold (6).

2. Heat exchanger according to claim 1, in which an outer contour (10) representing the end (8) of the respective flat tube (2) is at least partially adapted to an inner contour (12) representing the manifold (6).

3. Heat exchanger according to claim 1, in which an outer contour (10) representing the end (8) of the respective flat tube (2) is at least partially adapted to an outer contour (10) representing the manifold (6).

4. Heat exchanger according to one of claims 1 to 3, wherein the 0 end (8) at least one of the flat tubes (2) with one or more

Openings (13) is provided.

5. Heat exchanger according to one of claims 1 to 4, wherein the end (8) of at least one of the flat tubes (2) has an open contour or opening.

6. Heat exchanger according to one of claims 1 to 5, wherein the end (8) of at least one of the flat tubes (2) is provided with outside webs (20).

7. Heat exchanger according to one of claims 1 to 6, wherein the end (8) of at least one of the flat tubes (2) is provided with a further centrally arranged web (20).

8. Heat exchanger according to one of claims 2 to 7, in which the end (8) of the respective flat tube (2) is at least partially guided in a recess (14) extending in the inner contour (12).

Heat exchanger according to one of claims 1 to 8, in which the end (8) of the respective flat tube (2) is held integrally on the manifold (6).

10. Heat exchanger according to claim 8 or 9, in which the end (8) of the respective flat tube (2) along the recess (14) of the manifold (6) is soldered.

11. Heat exchanger according to one of claims 1 to 10, wherein the manifold (6) with at least one recess (24) or a recess (14) for performing one of the flat tubes (2) is provided.

12. Heat exchanger according to claim 11, wherein the end (8) of the relevant flat tube (2) on the recess (24) of the manifold. (6) is held integrally.

13. Heat exchanger according to one of claims 1 to 12, wherein the manifold (6) is divided into at least two areas (16) lengthways and / or crossways.

14. Heat exchanger according to one of claims 1 to 13, wherein the end (8) of at least one of the flat tubes (2) is provided with a slot (34) for receiving a partition (26).

15. A heat exchanger according to claim 14, wherein the partition (26) has a passage opening (32).

16. Heat exchanger according to one of claims 1 to 15, in which the flat tubes (2) end in each case in an associated manifold (6).

17. The heat exchanger according to claim 16, in which the manifolds (6) arranged at the ends on the flat tubes (2) are of uniform design.

18. Heat exchanger according to one of claims 1 to 17, in which the flat tubes (2) arranged in a form-fitting manner in the manifold (6) have differently shaped ends (8).

19. Heat exchanger according to one of claims 1 to 18, in which at least one of the flat pipes (2) arranged in a form-fitting manner in the manifold (6) is closed and acts as a partition.

20. Air conditioning system for a vehicle with a heat exchanger (1) according to one of claims 1 to 19.