EP1558887B1 - Multiple-pass heat exchanger, in particular for motor vehicle - Google Patents

Abstract

The heat exchanger has a collector (18) receiving the ends of multiple tubes (12,14). A collector box (20) covers the collector, and has a longitudinal wall (40) in contact with the collector defining first (50) and second (52) compartments into which the tubes open. The collector has a hollow region (56) facing the wall (40) to allow communication between the first and second compartments.

Description

The invention relates to heat exchangers, in particular for motor vehicles.

It relates more particularly to a heat exchanger of the type comprising a collector in which are received the ends of at least one row of tubes, and a collector box which covers the collector and which has a longitudinal partition whose free edge is in contact with the collector to delimit a first compartment and a second compartment into which at least a portion of the tubes respectively open.

Such a heat exchanger is known from the publication US 5,327,959A .

In such a heat exchanger, the row (s) of tubes together form a bundle of tubes which usually have associated heat exchange surfaces, such as, for example, corrugated inserts.

Most often, the heat exchanger includes a first manifold / header assembly at a first end of the tube bundle and a second manifold / header assembly at a second end of the bundle of tubes.

Such a heat exchanger may comprise, for example, a first row of tubes and a second row of tubes which open respectively into the first compartment and the second compartment.

The fluid that flows through the tubes of the bundle usually circulates in several passes in the first row of tubes, usually with countercurrent flows, to then gain the second row of tubes where it usually circulates in several passes and against the current. .

It is therefore necessary to be able to pass the fluid from one longitudinal compartment to an adjacent longitudinal compartment and thus pass from one sheet to another.

Alternatively, the heat exchanger may comprise a single row of tubes which each delimit a plurality of fluid flow channels. In this case, a first portion and a second portion of the channels of each tube can lead respectively into the first compartment and the second compartment.

In this case, there is also the problem of the passage of the fluid from one longitudinal compartment to another longitudinal compartment.

In known exchangers, this passage is usually made through one or more openings in the longitudinal partition, as taught for example by the publication US 2002/0066553 .

Thus, the passage of a longitudinal compartment to another longitudinal compartment that corresponds to the function "change tablecloth" is made through the longitudinal partition through openings formed through it. It will be appreciated that the term "web" may refer both to a row of tubes (usually in a multi-row tube heat exchanger) and to a portion of the tubes of a row (usually in the case of a heat exchanger). of heat to a single row of tubes).

This known solution therefore requires an additional operation for the realization of the opening or openings considered.

The object of the invention is in particular to overcome this disadvantage.

It aims to propose another solution, much simpler, to allow the passage of fluid from one longitudinal compartment to another, without the need to cross the longitudinal partition.

According to the invention, this solution applies to different types of heat exchangers, whether they are exchangers with a single row of tubes, two rows of tubes, or more than two rows of tubes.

The invention proposes for this purpose a heat exchanger of the type defined above, wherein the collector comprises at least one deformation to form at least one communication passage between the first compartment and the second compartment.

The deformation of the collector may have different shapes. However, preferably, it is constituted by at least one recessed region which is remote from the free edge of the longitudinal partition.

With this feature, it is possible to use a solid longitudinal partition, which avoids providing special tools to perforate said partition.

Thus, thanks to a particular arrangement of the collector, a communication passage is formed which extends between this hollow region of the collector and the partition, which allows the fluid to pass under the longitudinal partition, without crossing.

This solution is particularly advantageous because it allows this communication passage through a collector arrangement that can be achieved in a simple manner.

Advantageously, at least one communication path is provided in an end region of the compartments.

According to another characteristic of the invention, at least one communication passage defines a calibrated passage section.

This calibration makes it possible to minimize the pressure drops of the fluid passing through this section. In the case where the communication passage is made by several openings, the calibration of these also allows to control the flow rate through each opening. This balances the flow rates through the different tubes of the exchanger.

In a first general embodiment of the invention, the manifold and the manifold are formed of two separate parts.

In this case, the collector is preferably made in the form of a metal plate in which the recessed region is formed by stamping.

It is advantageous, in this case, that the manifold is a constant section form incorporating the longitudinal partition. This form can be obtained by extrusion or drawing of a material, preferably metal, or by molding a material, preferably a plastic material.

In a second general embodiment of the invention, the manifold and the header are formed in one piece. In this case, it is advantageous that the collector and the header are formed from a metal sheet having a central portion forming the collector, including its recessed region, and two marginal portions bent towards the central portion for contribute to delimit the compartments and to train jointly the longitudinal partition.

In this second embodiment of the invention, the recessed region of the collector is advantageously formed by stamping the central portion of the metal sheet.

The invention can be applied, for example, to a heat exchanger comprising a first row of tubes and a second row of tubes which open respectively into the first compartment and into the second compartment.

It can also be applied, for example, to a heat exchanger comprising a single row of tubes each delimiting a plurality of fluid circulation channels, a first portion and a second portion of the channels of each tube opening respectively in the first compartment and in the second compartment.

The invention applies in particular to a heat exchanger in which the tubes are flat tubes, the exchanger further comprising corrugated spacers in contact with the tubes.

The heat exchanger of the invention is advantageously made in the form of an evaporator for an air conditioning circuit of a motor vehicle. Of course, this application is not limiting, and the heat exchanger can also be used to form an air conditioning condenser or a radiator for cooling a motor vehicle engine, or a heating radiator. a passenger compartment of a motor vehicle.

• la figure 1 est une vue en perspective et partiellement éclatée d'un échangeur de chaleur à deux rangées de tubes selon l'invention ;
• la figure 2 est un détail à échelle agrandie de la figure 1 ;
• la figure 3 est une vue en coupe transversale d'un ensemble collecteur/boîte collectrice selon une autre forme de réalisation de l'invention ;
• la figure 4 est une vue partielle en perspective éclatée d'un échangeur de chaleur à une seule rangée de tubes selon l'invention ; et
• la figure 5 est une vue d'extrémité, à échelle agrandie, de l'échangeur de chaleur de la figure 4.

In the description which follows, made only by way of example, reference is made to the appended drawings, in which:

• the figure 1 is a perspective and partially exploded view of a heat exchanger with two rows of tubes according to the invention;
• the figure 2 is an enlarged detail of the figure 1 ;
• the figure 3 is a cross-sectional view of a manifold / header assembly according to another embodiment of the invention;
• the figure 4 is a fragmentary perspective exploded view of a heat exchanger single row of tubes according to the invention; and
• the figure 5 is an end view, on an enlarged scale, of the heat exchanger of the figure 4 .

The heat exchanger shown on the figure 1 comprises a beam 10 formed of a first row of tubes 12 which constitutes a first ply (here directed towards the front) and a second row of tubes 14 which constitutes a second ply (here directed towards the rear). These flat tubes are arranged parallel to each other, each tube of a first row being aligned with a corresponding tube of the second row. Corrugated inserts 16 forming heat exchange surfaces are in mechanical and thermal contact with the respective tubes of the two rows. In the example, the tubes 12 and 14 are obtained by extrusion of a metallic material, advantageously based on aluminum, and they each comprise a multiplicity of interior channels, which is better seen on the detail of the figure 2 , for the circulation of a fluid. This exchanger can in particular be made in the form of an evaporator for an air conditioning circuit, the fluid flowing through the tubes then being a refrigerant fluid.

The ends of the tubes 12 and 14 are received on the one hand in a manifold 18 (here in the upper part) capped by a manifold 20 and on the other hand in a manifold 22 (here at the bottom) capped by a box The collector 18 is a generally rectangular metal plate having a generally flat bottom 26 which is folded at both ends to form two upstanding edges 28 and 30.

The bottom 26 of the collector 18 is pierced with apertures of appropriate shape which respectively receive the ends of the tubes 12 and 14. The bottom 26 of the collector protrudes from the beam 10 (on the left side of the figure 1 ) to form an extension in which are arranged an inlet port 32 and an outlet port 34 for the fluid flowing in the exchanger. These two orifices 32 and 34 are spaced in the transverse direction, the orifice 32 being situated on the side of the row of tubes 12 and the orifice 34 on the side of the row of tubes 14.

The collecting box 20, which forms a lid, is constituted here of an extruded profile, advantageously made of metallic material, for example based on aluminum. This profile is shaped and has a constant section which has the shape of a double U formed by a first U-shaped wall 36 located on the side of the tubes 12 and a second U-shaped wall 38 located on the side of the tubes 14. The junction between the two walls forms a partition 40 having a free edge 42 adapted to come into sealing contact with the bottom 26 of the manifold in a region between the row of tubes 12 and the row of tubes 14. The contact zone is designated by the reference 44.

When the manifold 20 is assembled on the manifold 18, the assembly delimits two longitudinal chambers on either side of the partition 40, a first chamber communicating with the tubes 12 and a second chamber communicating with the tubes 14. These two longitudinal chambers are themselves divided, in the length direction, by a transverse partition 46. In this way, the two longitudinal chambers are divided into four compartments: a compartment 48 in which opens a portion P1 of the tubes 12 (here consisting of fifteen tubes), a compartment 50 into which opens a second portion P2 of the tubes 12 (here composed of fifteen tubes 12). Correspondingly, the wall 38 delimits, in conjunction with the transverse partition 46, a compartment 52 into which a portion of the tubes 14 (here fifteen in number) and one compartment 54 into which a portion of the tubes 14 (here at number of fifteen).

The manifold 24 covering the manifold 22 is similar to the manifold 20, which allows to use the same type of profile. This manifold thus delimits two longitudinal chambers which, unlike the upper manifold 20, are not divided by a transverse partition.

In the exchanger of the figure 1 , the fluid enters the compartment 48 through the inlet port 32, circulates in the tubes 12 of the P1 part to gain a first longitudinal chamber of the manifold 24 and reach the tubes 12 of the P2 part. From there, the fluid gains the compartment 50. It then gains the compartment 52 in the transverse direction, by particular arrangements that will be described later. The fluid circulates in one part of the tubes 14 to reach the second longitudinal chamber of the manifold 24 and then circulate in another part of the tubes 14 to reach the compartment 54. Finally, the fluid leaves the exchanger through the outlet orifice 34.

As already indicated, to allow the communication of the compartment 50 to the compartment 52, previously provided facilities, that is to say, openings in the partition 40.

The invention avoids this solution through a particular arrangement of the bottom 26 of the collector. As we see it best on the detail of the figure 2 , the bottom 26 of the collector comprises a deformed region, here a hollow 56 which has the shape of a bowl of substantially rectangular contour and which is situated on the side of the erected rim 30. In this hollow region open, in the example, Seven tubes 12 and seven tubes 14. As a result, in this region, the free edge 42 of the partition is no longer in contact with the bottom 26 of the collector, which thus delimits a communication passage 58 between the compartments 50. and 52 as illustrated by the arrows F on the figure 2 . The communication passage 58 has a calibrated passage section determined inter alia by the distance between the free edge 42 of the partition 40 and the recessed region 56.

The exchanger of figures 1 and 2 is formed only from metal components that can be soldered in a single operation in a suitable soldering furnace. For this, the metal components are coated with solder plating, as is well known in the art.

Alternatively, the manifold 20 could be crimped on the manifold 18 by appropriate means, for example by tabs from the manifold and bearing on the edges of the manifold. The latter could, alternatively, be made of plastic.

It is also conceivable to make the manifold assembly 18 / manifold 20 in one piece. For this, as shown in figure 3 it is possible to use a metal sheet 60 having a central portion 62 for forming the collector and two marginal portions 64 intended to be folded towards the central portion. These two marginal portions have respective free edges 66 which are applied against the central portion 62 to jointly form a central partition 40. The central portion 62 is deformed, preferably by stamping, to form the recessed region 56 and thus the communication passage 58 communicating the two compartments adjacent.

To achieve a collector / collector box in this way, one starts from a flat metal sheet of generally rectangular shape. Firstly, in the central portion, the passage openings of the tubes are formed and then this central portion is pressed over part of its length to form the recessed region 56. In a subsequent step, the two marginal portions 64 are folded towards the central portion to delimit the compartments and jointly form the longitudinal partition.

The heat exchanger shown in Figures 4 and 5 is similar to that of figures 1 and 2 except that it comprises here a single row of tubes 70, here flat tubes, between which are arranged corrugated tabs 12.

The tubes 70 are called "multi-channel tubes" because they each delimit a plurality of fluid circulation channels 72 which extend parallel to each other. These tubes are made by extrusion. The channels 72 of each tube 70 are divided into two parts N1 and N2 which, in the example, comprise the same number of channels. These two parts N1 and N2 are separated by an interval 74, which is substantially in the middle of the tube, and which is devoid of channels.

The collector 18 here receives a collecting box 20 similar to that of the figures 1 and 2 . When the latter is applied against the collector, the free edge 42 of the partition comes to rest on the respective intervals 74 of the tubes 70 which open into the recessed region 56. In this way, the first parts N1 of the tubes 70 and the second parts N2 of the tubes 70 respectively constitute two plies which respectively open into compartments 50 and 52 similar to those described previously with reference to the figures 1 and 2 . The fluid can thus pass from the first ply to the second ply or vice versa via the recessed region 56.

It will be understood that the invention is capable of numerous variants. Each manifold / header assembly may be formed of two parts or a single part as mentioned above. It is also possible to provide that the exchanger comprises more than two rows of tubes and that several communication passages are provided in the same manifold / collection box.

The invention finds particular application to heat exchangers for motor vehicles. As such, one of the preferred applications is that of an evaporator for an air conditioning circuit. However, other exchangers can be made according to this technique.

Claims (18)

1. Heat exchanger of the type comprising a manifold (18) into which arrive the ends of at least one row of tubes (12; 14; 70), as well as a collector box (20) which covers the manifold and which has a longitudinal partition wall (40) of which one free end is in contact with the manifold to define a first compartment (50) and second compartment (52) in which open out at least part of the tubes (12; 14; 70), characterised in that the manifold (18) includes at least one deformation (56) to form at least one communication passage (56) between the first compartment (50) and the second compartment (52).
2. Heat exchanger of claim 1, characterised in that the longitudinal partition wall (40) is solid.
3. Heat exchanger of any of claims 1 or 2, characterised in that the deformation (56) of the manifold (18) is composed by at least one hollow portion (56) that is remote from the free end (42) of the longitudinal partition wall (40).
4. Heat exchanger of any of claims 1 to 3, characterised in that at least one communication passage (56) is provided in an end portion of the compartments (50, 52).
5. Heat exchanger of any of claims 1 to 4, characterised in that at least one communication passage (56) defines a calibrated passage section (58).
6. Heat exchanger of any of claims 1 to 5, characterised in that the manifold (18) and the collector box (20) are formed by two separate parts.
7. Heat exchanger of claim 6, characterised in that the manifold (18) is a metal plate in which the hollow portion (56) is formed by stamping.
8. Heat exchanger of any of claims 6 or 7, characterised in that the collector box (20) has a shape with a constant cross section which incorporates the longitudinal partition wall (40).
9. Heat exchanger of claim 8, characterised in that the collector box (20) is formed by an extruded material, preferably metallic.
10. Heat exchanger of claim 8, characterised in that the collector box (20) is formed by a stamped material, preferably metallic.
11. Heat exchanger of claim 8, characterised in that the collector box (20) is formed by a moulded material, preferably plastic.
12. Heat exchanger of any of claims 1 to 5, characterised in that the manifold (18) and the collector box (20) are formed from a same part.
13. Heat exchanger of claim 12, characterised in that the manifold (18) and the collector box (20) are formed from a metal sheet (60) with a central portion (62) which forms the manifold, including its hollow portion (56) and two marginal portions (64), that are folded towards the central section to help define the compartments (50, 52) and together to form the longitudinal partition wall (40).
14. Heat exchanger of claim 13, characterised in that the hollow portion (56) of the manifold is formed by stamping of the central portion (62) of the metal sheet (60).
15. Heat exchanger of any of claims 1 to 14, characterised in that it comprises a first row of tubes (12) and a second row of tubes (14) which respectively open out into the first compartment (50) and the second compartment (52).
16. Heat exchanger of any of claims 1 to 14, characterised in that it comprises a single row of tubes (70) each defining a plurality of ducts (72) in which fluid circulates, and in that a first part (N1) and a second part (N2) of the ducts of each tube each open out respectively into the first compartment (50) and the second compartment (52).
17. Heat exchanger of any of claims 1 to 16, characterised in that the tubes (12; 14; 70) are flat tubes and in that it further comprises wave-shaped spacer parts (16) in contact with the tubes.
18. Heat exchanger of any of claims 1 to 17, characterised in that it forms an evaporator for an air conditioning circuit, especially for an automobile vehicle.

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