WO2017158300A1

WO2017158300A1 - Heat exchanger and associated manufacturing method

Info

Publication number: WO2017158300A1
Application number: PCT/FR2017/050605
Authority: WO
Inventors: Kamel Azzouz; Benjamin Ferlay
Original assignee: Valeo Systemes Thermiques
Priority date: 2016-03-18
Filing date: 2017-03-16
Publication date: 2017-09-21
Also published as: EP3430341A1; CN109154480A; CN109154480B; FR3049051B1; FR3049051A1

Abstract

The invention relates to a heat exchanger (1) comprising: - a bundle (2) of tubes (20); - a header (3) comprising a header plate (31) with holes into which ends of tubes (20) are introduced, and a cover (32) that covers the header plate (31); and - a partition (33) in at least one header, said partition (33) defining two compartments (37a, 37b) in the header (3). The cover (32) includes at least one flow rate restrictor (34) that is disposed at least in part above the end of at least one of the tubes (20) located in the immediate vicinity of the partition (33).

Description

Heat exchanger and method of manufacturing the same

The invention relates to a heat exchanger, in particular for a motor vehicle, and its method of manufacture.

It relates more particularly to a heat exchanger of the type comprising a multiplicity of tubes between which are inserted tabs. At each end of the bundle, the heat exchanger comprises a manifold for distributing and / or receiving the fluid circulating within the tubes. In some types of heat exchangers, a manifold or even both manifolds have a divider wall that defines two compartments. This is particularly the case for heat exchangers having a U-shaped fluid circulation where a first manifold comprises a separating wall, a first compartment for the arrival of fluid and a second compartment for the evacuation of the fluid, the second collector being closed and only redirect the fluid from the first compartment to the second compartment. This is also the case for dual circulation heat exchangers, where two different fluids or different fluids circulate in different compartments. In this case, each manifold has a separating wall and comprises two compartments in which separate fluids circulate.

However, whether for U-shaped heat exchangers or dual circulation heat exchangers, there may be a strong thermal differential between the fluids at the ends of the tubes located at the direct periphery of the separating walls. This high temperature differential causes thermal shocks in the tubes and spacers, which can lead to premature deterioration or even breakages of the latter and therefore leaks. One of the aims of the present invention is therefore to at least partially overcome the disadvantages of the prior art and to provide an improved heat exchanger.

The present invention therefore relates to a heat exchanger comprising: a bundle of tubes,

⁰ a manifold having a manifold plate comprising holes in which are inserted the ends of the tubes, and a cover covering said collecting plate, and

⁰ a partition wall disposed in at least one manifold, said partition wall defining two compartments within said manifold, said cover having at least one flow restrictor from position at least partially above the end of at least one of tubes located at the direct periphery of the separating wall.

This reduction in fluid flow allows a reduction in the temperature difference between the tubes located on either side of the separating wall in its direct periphery. The thermal shock at this level is therefore less important and the heat exchanger is therefore less likely to deteriorate at the separating wall. The fact of integrating the flow restrictor or the cover allows in particular to facilitate the mounting of the heat exchanger. Indeed, said one or more flow restrictors are installed by the implementation of the cover and do not require a dedicated implementation step.

According to one aspect of the invention, the lid comprises two flow restrictors disposed on either side of the separating wall.

According to another aspect of the invention, the tube or tubes located at the direct periphery of the separating wall have a fluid flow rate between 0 and 20, preferably between 1 and 10, of their theoretical flow. According to another aspect of the invention, the flow restrictor comes from material with the lid. According to another aspect of the invention, the dividing wall comes from material with the lid.

According to another aspect of the invention, the lid comprises a recess directed towards the header plate, said recess forming the flow reducer (s) and the separating wall.

According to another aspect of the invention, the flow restrictor comprises a lateral projection of the separating wall. According to another aspect of the invention, the flow restrictor has a length such that it is positioned only above the tube located at the direct periphery of the separating wall.

According to another aspect of the invention, the flow restrictor has a length such that it is positioned above at least the first two tubes located at the direct periphery of the separating wall.

According to another aspect of the invention, the distance between the end of a tube above which the flow restrictor is positioned and said restrictor increases as said tube is moved away from the separating wall.

Other features and advantages of the invention will emerge more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which: FIG. 1 is a schematic sectional representation of a heat exchanger according to a first embodiment,

FIG. 2 is a diagrammatic representation in section of the zone of the collector comprising the separating wall according to a particular embodiment,

FIG. 3 is a diagrammatic representation in section of the zone of the collector comprising the separating wall according to another particular embodiment,

FIG. 4 is a diagrammatic sectional representation of a heat exchanger according to a second embodiment,

FIG. 5 is a diagrammatic sectional representation of a heat exchanger according to a third embodiment,

FIG. 6 is a schematic representation in section of a variant of the heat exchanger of FIG. 5.

The identical elements in the different figures bear the same references.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined to provide other embodiments. In the present description, it is possible to index certain elements or parameters, for example first element or second element as well as first parameter and second parameter, or first criterion and second criterion, and so on. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria close but not identical. This indexing does not imply a priority one element, parameter or criterion with respect to another and it is easy to interchange such denominations without departing from the scope of the present description. This indexing does not imply either an order in time for example to appreciate such or such criteria.

The heat exchanger 1 shown in FIGS. 1 to 6 comprises a bundle 2 formed of a multiplicity of tubes 20 within which a first fluid can circulate. The tubes 20 are arranged parallel to each other. Between the tubes 20, interleaves 21 are arranged which act as a disrupter and increase the heat exchange surface with a second fluid passing between said tubes 20. The tubes 20 and the spacers 21 are preferably made of metal materials and are brazed between them in order to form the beam 2. Having a brazed beam 2 improves the thermal performance, ie the heat exchange between the two heat transfer fluids, compared to a mechanically assembled beam. The tubes 20 preferably have, in cross section, an oblong and relatively flat shape or a substantially rectangular shape with rounded corners.

The heat exchanger 1 also comprises two collectors 3, or water boxes, disposed at each end of the bundle 2. These collectors 3 comprise a header plate 31 and a cover 32, 32 'coming to cover said header plate 31 and close the collector 3. The seal between the cover 32, 32 'and the collector plate 31 can in particular be made by a seal 4. These collectors 3 allow the collection and / or distribution of the first fluid so that it circulates in the tubes 20. The collecting plate 31 makes the connection sealingly between the collector 3 and the bundle 2. Said collector plate 31 comprises a core, which may be of generally rectangular shape, delimiting a multiplicity of holes of section corresponding to the shape of the section of the tubes. 20 and adapted to receive the ends of said tubes 20. As illustrated in FIGS. 1, 4 to 6, the heat exchanger 1 comprises two collectors 3, at least one of them has a separating wall 33 defining two compartments 37a and / or 37b within said collector 3. Each compartment 37a, has an inlet 30a and each compartment 37b has a fluid outlet 30b. The separating wall 33 connects the cover 32 and the collector plate 31 and bears against the collector plate 31 between two ends of tubes 20. The seal of this support can be provided by a seal 4 '. Said separating wall 33 may in particular be integral with the cover 32. The cover 32 of the manifold 3 comprising the separating wall 33 also comprises at least one flow restrictor 34 which is positioned at least partially above the end of the at least one of the tubes 20 located at the direct periphery of the separating wall 33, so as to reduce the flow rate of fluid flowing in said tubes 20. This reduction in the flow rate of the fluid at this level makes it possible to reduce the temperature difference between the tubes 20 located on either side of the partition wall 33 in its direct periphery. The thermal shock at this level is therefore less important and the heat exchanger 1 is therefore less likely to deteriorate at the separating wall 33. The fact of integrating the flow restrictor or 34 to the lid 32 allows in particular to facilitate the mounting of the heat exchanger 1. Indeed the said flow restrictor or 34 are installed by the introduction of the cover 32 and do not require a dedicated implementation step.

As illustrated in Figures 1 to 4, the cover 32 may comprise two flow restrictors 34 disposed on either side of the separating wall 33. The fact of having a flow restrictor 34 on each side of the separating wall 33 allows a better reduction of the flow of the fluid within the tubes 20 located on either side of the separator plate 33 and above which is positioned a flow reducer 34. Conversely, it is quite possible to imagine a cover 32 having only one flow restrictor 34 located on only one side of the collecting wall 33, as shown in Figures 5 and 6. The Flow reducers 34 may also be integral with the cover 32, as well as the separating wall 33. As a result, the cover 32, the separating wall 31 and the flow restrictor (s) 34 may be formed in one go, by example by molding. However, it is also possible, without departing from the scope of the invention, the or the flow restrictors 34 are made of material with only the cover 32, the partition wall 33 being an insert and installed during assembly to separate the compartments 37a and / or 37b.

As illustrated in FIGS. 1, 2 and 4, the cover 32 may comprise a recess 35 directed towards the collecting plate 31. This recess 35 allows the wall of the cover 32 to approach the collecting plate 31 so as to form the reduction gearbox. flow 34. Said recess 35 is extended until it bears on the collector plate 31 so as to also form the separating wall 33, as illustrated in FIGS. 1, 2 and 4.

The flow reducer 34 may comprise a lateral projection of the separating wall 33 as illustrated in FIGS. 3, 5 and 6.

The flow restrictor 34 extends a length L from the partition wall 33. This length L may be such that at least the first two tubes 20 located at the direct periphery of the partition wall 33 have a flow restrictor 34 is positioned above them, as shown in Figure 2. The length L may instead be such that only the first tube 20 located at the direct periphery of the partition wall 33 has a flow restrictor 34 positioned above him, as shown in Figure 3. The tube or tubes 20 having a flow restrictor 34 positioned above them, more particularly the tubes 20 situated at the direct periphery of the separating wall 33, may have a fluid flow rate of between 0 and 20, preferably between 1 and 10, their theoretical flow. By theoretical flow rate is meant the flow rate corresponding to the flow rate of fluid between the fluid inlet 30a and the fluid outlet 30b, divided by the number of tubes 20 in which the fluid flows in the same direction (in the example of FIG. 1 heat exchanger illustrated in Figure 1, this number is three). A first flow control means is to play on the distance D between the end of a tube 20 having a flow restrictor 34 positioned above it and said flow reducer 34. The smaller this distance D is, the smaller the the flow will be weak too. In the particular case where the flow rate is 0, the flow restrictor 34 blocks the tube 20, the distance D will then be 0, and prevents any fluid flow within it.

Another way of controlling the flow rate is to vary the length L of the flow restrictor 34. In fact, the more a flow restrictor 34 is positioned above a tube end 20, the greater the flow rate of fluid passing through said tube. 20 will be weak. Thus, when a flow reducer 34 is positioned partially above a tube 20, said tube 20 will have a larger fluid flow rate than a tube 20 where a flow reducer 34 is positioned above any the tube end 20.

As illustrated in FIG. 2, it is also possible to imagine a flow restrictor 34 whose distance D with the end of at least one tube 20 increases as said tube 20 is moved away from the separating wall 33. the example illustrated in Figure 2, a flow restrictor 34 is positioned above two tubes 20 simultaneously. The tube 20 closest to the separating wall 33 has a distance D with the flow restrictor 34 smaller than the tube 20 farthest from the separating wall 33. These two tubes 20 then both have a reduced but different flow rate. one of the other.

According to a first embodiment illustrated in FIG. 1, the heat exchanger 1 can be a heat exchanger 1 having a U-shaped fluid circulation. one of the two collectors 3 has a separating wall 33, the other collector 32 'comprising for its part a single compartment 37c closed which allows the circulation of the fluid between the tubes 20. This heat exchanger 1 may for example be a heat exchanger 1 of the air / air type.

According to a second embodiment illustrated in FIGS. 4 to 6, the heat exchanger 1 may be a heat exchanger 1 having a double circulation of fluid. In this embodiment, each manifold 3 has a partition wall 33 defining two compartments 37a and / or 37b within said manifold 3. Each manifold 3 thus comprises a compartment 37a having an inlet 30a and / or a compartment 37b having an outlet 30b of fluid. In this heat exchanger 1 with double circulation, two fluids each arrive at a different fluid inlet 30a, circulate in the tubes 20 and each spring at a different fluid outlet 30b located on the collector 3 opposite the one carrying the fluid inlet 30a. .

In the example shown in FIGS. 4 and 5, the circulation of the fluid is in the opposite direction, that is to say that the manifolds 3 both comprise a compartment 37a comprising a fluid inlet 30a and another compartment 37b comprising an outlet fluid 30b.

It is nevertheless quite possible to imagine a heat exchanger 1 where the flow of fluids is in the same direction and where a manifold 3 has two compartments 37a both having a fluid inlet 30a and the other manifold 3 comprises two compartments 37b both having a fluid outlet 30b, as shown in FIG. 6. Thus, because the flow restrictor (s) 34 are carried by the lid

32, it is understood that the heat exchanger 1 according to the invention allows a more economical assembly because possibly requiring mounting steps while allowing a decrease in fluid flow within the tubes 20 located on either side of the dividing wall 33, which decreases the intensity of the thermal shocks at this location and therefore increases the durability of the heat exchanger.

Claims

A heat exchanger (1) comprising:

A bundle (2) of tubes (20),

⁰ a manifold (3) having a header plate (31) comprising holes in which are inserted the ends of the tubes (20), and a cover (32) overlying said collector plate (31), and

⁰ a dividing wall (33) disposed in at least one manifold, said partition wall (33) defining two compartments (37a, 37b) within said manifold (3),

characterized in that said cover (32) comprises at least one flow restrictor (34) coming to be positioned at least partially above the end of at least one of the tubes (20) located at the direct periphery of the separating wall (33).

2. Heat exchanger (1) according to claim 1, characterized in that the cover (32) comprises two flow restrictors (34) disposed on either side of the separating wall (33).

3. Heat exchanger (1) according to one of the preceding claims, characterized in that the tube or tubes (20) located at the direct periphery of the separating wall (33) have a fluid flow rate between 0 and 20, of preferably between 1 and 10, of their theoretical flow.

4. Heat exchanger (1) according to one of the preceding claims, characterized in that the flow restrictor (34) comes from material with the cover (32).

5. Heat exchanger (1) according to one of the preceding claims, characterized in that the separating wall (33) is made of material with the cover (32).

6. Heat exchanger (1) according to one of the preceding claims, characterized in that the cover (32) comprises a recess (35) directed towards the header plate (31), said recess (35) forming the reducer (s) the flow (34) and the separating wall (33).

7. Heat exchanger (1) according to one of claims 1 to 6, characterized in that the flow restrictor (34) comprises a lateral projection of the separating wall (33).

8. Heat exchanger (1) according to one of the preceding claims, characterized in that the flow restrictor (34) has a length (L) such that it is positioned only above the tube (20) located in direct periphery of the separating wall (33).

9. Heat exchanger (1) according to one of claims 1 to 7, characterized in that the flow restrictor (34) has a length (L) such that it is positioned above at least the first two tubes (20) located at the direct periphery of the separating wall (33).

10. Heat exchanger (1) according to the preceding claim, characterized in that the distance (D) between the end of a tube (20) above which is positioned the flow reducer (34) and said reducer of flow rate (34) increases as said tube (20) is moved away from the separating wall (33).