WO2006035149A1

WO2006035149A1 - Heat exchange insert for a heat exchange device

Info

Publication number: WO2006035149A1
Application number: PCT/FR2005/002368
Authority: WO
Inventors: Paul Garret; Jens-Peter Arnesen
Original assignee: Valeo Systemes Thermiques
Priority date: 2004-09-29
Filing date: 2005-09-23
Publication date: 2006-04-06
Also published as: FR2875896A1; EP1817535A1; FR2875896B1

Abstract

The invention relates to a heat exchange device, e.g. for a motor vehicle, comprising a bundle of first tubes that are separated from each other by a first space and a bundle of second tubes that are separated from each other by a second smaller space, as well as a plurality of heat exchange inserts (40) which are corrugated in the form of bent strips of sheet metal such as to form a succession of essentially-flat segments (42) which are each disposed between two first tubes and between two second tubes and which are connected in pairs by means of a bent joining segment (44a) having dimensions adapted to the above-mentioned first space and comprising a slit (60) that defines a first bent contact segment (44) which is designed to co-operate with one of the first tubes (8) and a second bent segment (46A). The second bent segment (46A) is folded down to form a second contact segment (46) which has dimensions adapted to the aforementioned second space and which is designed to co-operate with one of the second tubes, thereby enabling each insert (40) to be adapted to the first space and the second space.

Description

Heat exchange spacer for a heat exchange device

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

It relates more particularly to a heat exchange device comprising a bundle of first tubes spaced apart from a first interval and a bundle of second tubes spaced apart by a second interval, the second interval being smaller than the first interval, and a plurality corrugated heat exchanger interleaves in the form of folded sheet metal strips so as to form a succession of substantially planar portions each disposed between two first tubes and between two second tubes, and connected in pairs by a bent junction portion of dimension adapted to the first intervals, the angled junction portion having a cutout defining a first bent contact portion arranged to cooperate with one of the first tubes and a second bent portion.

The purpose of a heat exchange device is to allow the exchange of heat between one or more circulating fluids inside tubes and an external fluid passing through the heat exchange device. _. It is common to provide in such a device, a bundle of first tubes and a bundle of second tubes, in which circulates one or more fluids. To increase the performance of the heat exchange between the circulating fluid (s) at

1 inside the first and second tubes and the external fluid, it is common to provide the heat exchange device with means for increasing the exchange surface between the external fluid and the circulating fluid or fluids ^. inside the tubes. FR2005 / 002368

Thus it is known to provide the heat exchange device with a plurality of corrugated general heat exchange pads formed by the succession of substantially planar portions connected two by two by an angled junction portion. In general, a corrugated spacer is disposed between two first tubes and two second tubes so that a portion of the bent portion is in contact with both a first tube and a second tube.

However, it happens that the interval between two first tubes or first interval differs from the interval between two second tubes, or second intervals. This is particularly the case when the first tubes and the second tubes are sections of different dimensions. In this case, it is no longer possible to arrange between the first two tubes and two second tubes the same corrugated insert.

It is known from document US Pat. No. 6,213,196 B1 to provide a first interlayer of generally crenellated appearance, having slots of a size adapted to be lodged between two first tubes and to connect it to a second castellated spacer also having dimension slots. adapted to fit between two second tubes. However, the crenellated interlayer thus formed by the meeting of the first and second crenellated interlayer is particularly difficult to achieve.

The object of the invention is therefore to provide a new type of heat exchange device of the type mentioned in the introduction overcoming the aforementioned drawbacks.

The invention therefore provides a heat exchange device of the aforementioned type in which said second bent portion is folded to form a second contact portion of dimension adapted to the second gap and arranged to cooperate with one of the second tubes, which allows to adapt each interlayer at the first and second intervals. Thus, it is possible to make an interlayer from the same folded sheet metal strip and capable of being disposed between two first tubes and two second tubes and to cooperate with them.

In a first embodiment of the invention, the second bent portion is folded by flattening so that the second contact portion has a partial planar appearance.

In a second embodiment of the invention, the second bent portion is folded by an inverse fold so that the second contact portion has a bend appearance.

In another embodiment of the invention again, the second bent portion is folded by several reverse bends so that the second contact portion has a wavy appearance. This makes it possible to adapt the number of inverse bends to the dimension of said second bent portion to be folded down.

In a preferred embodiment of the invention, the first tubes and the second tubes are flat tubes.

Advantageously, the first tubes are multichannel tubes, which are resistant to the pressure of the circulating fluid inside the channels.

Advantageously, the flat portions have flux deflectors in the form of metal strips projecting from the flat portion. The flow deflectors, by disturbing the flow of the external fluid passing through the device, improve the heat exchange performance. In a preferred embodiment of the invention, the heat exchange device is composed of a heat exchanger. 02368

condenser-type heat comprising the bundle of first tubes and a radiator-type heat exchanger comprising the bundle of associated second tubes, which makes it possible to group in a single product several heat exchangers and to save production shared parts, such as dividers for example.

In a replacement embodiment, the bundle of first tubes and the bundle of second tubes are part of the same heat exchanger.

Preferably, the spacers are made from a sheet of aluminum alloy sheet which is a material easy to bend and having good thermal characteristics.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawings in which:

FIG. 1 is a perspective view of a heat exchange device in a preferred embodiment of the invention,

FIG. 2 is a sectional representation of a portion of the heat exchange device of FIG. 1 along the X-Y plane;

FIG. 3 is a sectional view along line III-III of part of FIG. 2,

FIG. 4 is a view of part of FIG. 3 in another embodiment of the invention, FIG. 5 is a view of a portion of a heat exchange pad of the device according to the invention in a manufacturing operation decomposed into steps,

FIG. 6 is a view of a portion of a heat exchange pad of the device according to the invention in the embodiment of FIG. 4 in a last step,

FIG. 7 is a sectional representation of a part of a heat exchange device according to the invention in a variant embodiment, and

FIG. 8 is a sectional representation of a part of the heat exchange device of FIG. 1 along the X-Y plane in an embodiment different from that of FIG. 2;

The attached drawings may not only serve to complete the invention, but also contribute to its definition, if any.

FIG. 1 shows, in perspective, a heat exchange module 2 comprising at least two bundles of tubes. Here, the heat exchange module 2 comprises a first 4 and a second 6 generally cylindrical tubular manifold respectively receiving the one and the other of the ends of the first tubes 8 of fluid circulation. The first tubes 8 are arranged aligned, regularly spaced apart from each other, and thus form a bundle of first tubes 8.

The first tubular collector 4 is partitioned so as to have a first chamber 10 and a second chamber 12. Thus, a part of the bundle of first tubes 8 is received in the first chamber 10, while the other part is received in the second room 12. The entire bundle of first tubes 8 is received in the second tubular collector 4.

The first chamber 10 of the first tubular manifold 4 is provided with a first fluid inlet tubing 14, while the second chamber 12 is provided with a first fluid outlet tubing 16.

Thus, a first fluid, coming from an upstream portion of a first fluid circuit, enters via the first fluid inlet manifold 14 into the first chamber 10 of the first tubular manifold 4, circulates in the first tubes 8 of the part of the beam received in the first chamber 10 and reaches the second tubular collector 6. From there, the first fluid flows through the first tubes 8 of the part of the beam received in the second chamber 12 of the first tubular collector 4 before exiting through the first fluid outlet tubing 16, which is connected to a downstream portion of the first fluid circuit.

The first tubes 8 thus belong to a first heat exchanger 18 furthermore composed of the first 4 and second 6 tubular collectors and the inlet and outlet pipes 14 and 16 of the first fluid. The first heat exchanger 18 illustrated in FIG. 1 is, for example, of the condenser type. Thus, in the first exchanger 18 for example, the first fluid enters the gas phase and spring in phaseliquide.

The heat exchange module 2 is furthermore composed of two generally parallelepipedal collecting boxes 20 receiving respectively one end and the other end of second fluid circulation tubes 22, not visible in FIG. 1. The second tubes fluid circulation 22 005/002368

are arranged aligned, regularly spaced apart from each other, and thus constitute a bundle of second tubes 22.

One of the manifolds 20 is further provided with a second fluid inlet pipe 24 while the other is provided with a non-repré¬ sented second fluid outlet pipe.

Thus, a second fluid, coming for example from an upstream portion of a second fluid circuit, enters one of the manifolds 20 via the second fluid inlet manifold 24. The second fluid circulates through the second tubes 22 to reach the other manifold 20. From there, the second fluid joins an upstream portion of the second fluid circuit via a not shown second fluid outlet tubing.

The bundle of second tubes 22 belongs to a second heat exchanger 26 further composed of two manifolds 20 and inlet pipes 24 and fluid outlet. The second heat exchanger 26 illustrated in Figure 1 is for example radiator type.

A heat exchange module such as the heat exchange module 2 makes it possible to carry out a first heat exchange between an external fluid, for example air, passing through said module and the first fluid and then to implement a second heat exchange between the external fluid and the second fluid circulating inside the second tubes 22.

In the example of FIG. 1, the first fluid may be CO2 carbon dioxide, while the second fluid may be a gaseous mixture coming from the engine of a vehicle in which the module is disposed. In the example illustrated here, the heat exchange module comprises two bundles of tubes. However, it is also conceivable that the heat exchange module has three or more bundles of tubes.

As shown in Figure 1, three directions X, Y and Z are defined as follows:

the largest dimension of the tubes, i.e. their length, is arranged in the Z direction,

the smallest dimension of the tubular collectors is arranged in the X direction, and

the direction Y is perpendicular to both the X and Z directions.

FIG. 2 is a partial sectional view of the heat exchange device of FIG. 1 along a plane perpendicular to the direction Z. FIG. 2 specifies the shape of the first tubes 8 and second tubes 22 as well as their arrangement. in relation to each other.

The first tubes 8 are so-called "flat" tubes having two identical parallel first planar faces 28 arranged symmetrically to each other and interconnected by two first semi-cylindrical surfaces 30. The distance separating the outside of two first planar faces 28 of the same first tube 8, generally called thickness, will be designated first thickness and denoted el. The first tubes 8 are arranged in alignment. More specifically, the flat faces 28 of all the first tubes 8 are arranged parallel to each other and perpendicular to the Y direction.

Each first tube 8 has a plane of symmetry P1 parallel to a plane XZ and located equidistant from the first two planar faces 28 of the same first tube 8. The distance separating two planes of symmetry S1 of two first Adjacent tubes 8, generally designated by the term of step, is designated here first step and denoted Pl. The first tubes being regularly spaced from each other, the bundle of first tubes 8 has a first constant pitch P1. 5

The distance separating a flat face 28 of a first tube 8 of the closest flat face 28 belonging to a first adjacent tube 8, generally called an interval, will be designated the first interval and denoted II. For the bundle of first 10 tubes 8, the first interval II is constant.

It should be noted that the first fluid circulation tubes 8 are provided with partitions delimiting several interior channels 32. Such tubes are sometimes referred to as

15 "multichannel tubes". Thus, the first tubes 8 are known as "multichannel flat tubes". The first tubes 8 described here are only exemplary. Other types of tubes, known to those skilled in the art, can be used here as first tubes 8, for example

Single-channel flat tubes or tubes of circular section.

As shown in FIG. 2, the second tubes 22 are also of the flat tube type provided with second plane faces

The second tubes 22 are not partitioned and thus define a single second fluid circulation channel 38. The second tubes described here are only one of them. They are parallel, symmetrical and connected by second half-cylindrical surfaces 36. for exemple. Other types of

30 tubes, known to those skilled in the art can be used here as second tubes 22, for example two-channel flat tubes (also referred to as "dual-channel tubes") or multi-channel flat tubes .

^• 35 Analogously to what has been described above in the case of first tubes 8, each second tube 22 has a plane of symmetry S2 and a thickness e2. The second fluid circulation tubes are arranged aligned, that is to say that their planar faces 34 are arranged parallel to each other and perpendicular to the Y direction. The second pitch of the second tube bundle 22 is constant and noted P2, while the second interval of the bundle of second tubes 22 is constant and noted 12.

As shown in FIG. 2, each first tube 8 is disposed aligned with a second tube 22, that is to say that the plane of symmetry Sl of a first tube 8 ^' coincides with the plane of symmetry S2 of a second tube 22. Since each first tube 8 thus corresponds to a second tube 22, the first pitch P1 and the second pitch P2 are equal.

On the other hand, the thickness e2 of the second tubes 22 is greater than the thickness e1 of the first tubes 8. Consequently, the first interval II is greater than the second interval 12.

The difference between the thicknesses e1 and e2 is due to the fact that the shape of the first 8 and second 22 tubes is adapted to the different functions of the first heat exchanger 18 and the second heat exchanger 26.

As shown in Figure 1, each time between two first tubes 8 and between two second tubes 22, is disposed a heat exchange spacer 40 of corrugated appearance. Each spacer 40 is made in the form of a folded sheet metal strip, for example aluminum alloy.

In the configuration of the module shown in FIG. 1, the arrangement of a spacer is such that: the length of the sheet metal strip at the origin of the spacer, ie the length of. the spacer is arranged in the Z direction; the width of the sheet metal strip at the origin of the insert, ie the width of the insert, is arranged in the direction X;

- The size of the interlayer along the Y direction will be called height.

3 shows, in profile, a portion of an insert 40. This consists of a succession of generally planar faces 42 taking the entire width of the insert, as defined above. The flat faces 42 are connected in pairs on a part of the width of the spacer by a first elbow contact portion 44. The first contact portion 44 results from the folding of the sheet metal strip intended to form the corrugated insert 40 .

As now shown in FIGS. 1 and 2, this first contact portion 44 bears on a first planar face 28 of a first fluid circulation tube 8 at its top. The first contact portion 44 extends over the entire width, ie their dimension in the X direction, of the first tubes 8. At the flat faces 34 of the second fluid circulation tubes 22, each corrugated insert 40 has a second portion contact 46. Each contact portion 46 consists of a bent central portion 48 connected to the flat faces 42 by two side portions 50 bent, of curvature opposite the curvature of the central portion 46 bent. The second contact portion 46 is bent inverted with respect to the first contact portion 44.

As shown now in FIG. 2 and as indicated in FIG. 3, the height of the flat faces 42 is substantially equal to the second gap 12. The height of a flat portion 42 extended on either side by bent contact portions 44 is close to the first interval II. FIG. 4 is a detail of FIG. 3 showing an alternative embodiment of the spacer 40. In FIG. 4, the second junction portion 46 is in the form of a flat central portion 52 connected to one side and to the other. another two planar portions 42 by two flat lateral portions 54 arranged according to the height of the spacer. Although this is not shown in FIG. 4, the height of the plane portions 42 associated with the contact portions 46 is close to the second gap 12. Thus, the central portion 52 can bear on a second tube 22.

As shown in FIGS. 3 and 4, the planar faces 42 of the parts of the spacer 40 in contact with the planar faces

28 of the first fluid circulation tubes 8 and the flat faces 42 of the parts of the spacer 40 in contact with the flat faces 34 of the second fluid circulation tubes 22 have an identical inclination angle.

Thus, the difference between the intervals II and 12 is obtained only by the only deformation of the contact portion 46 without deformation of the other parts of the spacer 40. It is therefore possible to accommodate a spacer 40 between two first tubes 8 and two second tubes 22, and this, despite different first and second intervals II and 12.

As shown in FIG. 2, the planar portions 42 are optionally provided with flow deflectors 56 in the form of sets of metal lamellae 58 cut in the flat portions and projecting from said flat portions 42 and intended to disturb the flow of a fluid passing through the heat exchange module 2.

Figure 5 illustrates schematically the sim¬ plified embodiment of the insert 40 in the configuration of Figure 3. In Figure 5, a single corrugation of corrugated insert 40 is shown. A conventional corrugated insert 40A is made according to a method known to those skilled in the art, for example by successive bends of a sheet metal strip sometimes called "strip". In particular, the conventional corrugated spacer 4OA is made in such a way that the height separating the vertices of two successive oscillations is close to the first interval II. The spacer 40A has a succession of flat faces 42 then connected by a joining portion 44A.

A cut 60 of the joining portion 44A. is then carried out according to the height of the spacer 40A so as to dissociate the first contact portion 44 and a second angled portion 46A forming a corrugated interbed intermediate 4OB. Note that the cutout 60 is made only on the joining portion 44A, that is to say at the level of the folding zone of the sheet metal strip forming the joining portion 44A.

An inverse folding is then carried out according to the edge defining the top of the corrugation and concerning the second angled portion 46A so as to form the second contact portion 46. The depth of the reverse folding is such that the height of the interlayer at the second contact portion 46 is close to the second gap 12. It will be noted that the radius of curvature of the first bent portion 44 remains unchanged.

FIG. 6 schematically and schematically illustrates the embodiment of the insert 40 illustrated in FIG. 4. FIG. 6 shows how to obtain the insert 40 illustrated in FIG. 4 from the insert 40B of FIG. settlement of the edge defining the top of the corrugation and concerning the second bent portion 46A forms the flat central portion 52. The settlement is such that R2005 / 002368

14 the height of the spacer at the second contact portion 46 is close to the second gap 12. Here too, the radius of curvature of the first bent portion 44 remains unchanged despite the settlement of the edge.

It should be noted that the steps illustrated in FIGS. 5 and 6 result from an arbitrary decomposition of a manufacturing operation of the heat exchange pad intended solely to better understand the invention. In practice, these steps can be performed during the same manufacturing operation using a tool known to those skilled in the art under the term "wheel".

The invention is of particular interest in the case of heat exchanger modules such as the heat exchange module 2 because the thicknesses of the first 8 and second 22 respectively el and e2 tubes are adapted to the functions of the tubes. However, the configuration of the corrugated insert 40 as described here still makes it possible to have this corrugated intercalate between first 8 and second 22 fluid circulation tubes.

Note that it is possible to make a spacer of the type illustrated in Figure 3 for example by means of several reverse bends in the case where the second elbow portion 46A is larger.

The shape of the second contact portion 46 in the case of the spacer 40 of Figure 5 may differ depending on the height of the second portion of the junction 44A to be flattened.

The heat exchange device described above is a heat exchange module combining two heat exchangers, each of them respectively comprising a bundle of tubes. The heat exchange pad 40 is then common to these two heat exchangers. Similarly, the heat exchange pad 40 may be employed in the case of a single heat exchanger comprising both the bundle of first tubes and the bundle of second tubes (22). The heat exchange pad 40 then belongs to the same heat exchanger and a single fluid circulates inside the tubes of the heat exchanger. In this case, advantageously, each of the bundles of tubes allows a circulation of the fluid in different states, which the skilled person knows as the pass.

FIG. 7 schematically illustrates an alternative embodiment of a heat exchange device according to the invention. In this FIG. 7, the tubes have been represented in a simplified manner. In the case illustrated by FIG. 7, the heat exchange device comprises a bundle of third tubes 62 identical to the first tubes 8 and spaced apart from the same first interval II.

In this case, the strip of metal sheet at the origin of the heat exchange pad 40 has either a cutout 60, but two cutouts 60 delimiting the second bent portion 46A, which is folded to form said second portion of contact 46. A third contact portion 64 of the insert 40 bearing on the side faces 28 of the third tubes 62, is identical to the first contact portion 44 at the level of the first tubes 8.

The configuration of FIG. 7 can be implemented in the same heat exchanger comprising the bundles of first tubes 8, second tubes 22, and third tubes 62. This configuration can also be used in the case of a first heat exchanger. comprising the bundles of first 8 and second tubes 22 associated with a second exchanger In the latter case, the heat exchange pad 40 is common to both heat exchangers.

FIG. 8 illustrates an alternative embodiment of the heat exchanger according to the invention, in which the first and second fluid circulation tubes respectively 8 and 22 are no longer aligned. The planes of symmetry Sl of the first tubes 8 and the planes of symmetry S2 of the second tubes 22 no longer coincide.

The second tubes 22 are, however, always spaced from the same gap 12. In this case, one of the lateral faces 34 and one of the lateral faces 28 of respectively second 22 and first 8 tubes, are aligned. As shown in Figure 8, in this case, there is provided a second elbow portion 46A folded to form a second contact portion 46 only one oscillation out of two of the corrugated insert 40. Once in two, the first contact portion bent 44 bears on the side faces 28 and 34 of the first and second tubes when they are aligned.

The invention is not limited to the embodiments described above only as examples, but encompasses all the variants that may be considered by those skilled in the art within the scope of the following claims.

Claims

R2005 / 00236817Revendications

1. corrugated heat exchange spacer in the form of sheet metal strips folded so as to form a succession of substantially planar portions (42) able to be arranged each between two first tubes (8) spaced apart by a first interval (II ), and between two second tubes (22) spaced apart by a second gap (12), the second gap being smaller than the first gap, and connected in pairs by an angled junction portion (44A) of a size adapted to the first gap ( II), the angled junction portion (44A) having a cutout (60) delimiting a first bent contact portion (44) arranged to cooperate with one of the first tubes 8 and a second bent portion (46A), characterized in that said second angled portion (46A) is folded down to form a second contact portion (46) of dimension adapted to the second gap (12) between the tubes and arranged to cooperate with one of the second tubes (22), said portion s substantially planar (42) and said first bent portion (44) remaining unchanged.

2. The spacer according to claim 2, such that said flat portions (42) of the parts of the spacer (40) in contact with the flat faces 28 of the first fluid circulation tubes (8) and the flat faces 42 of the parts of the the spacer (40) in contact with the planar faces (34) of the second fluid circulation tubes (22) have an identical inclination angle.

3. The spacer according to claim 1 or 2, such that the radius of curvature of the first bent portion (44) remains unchanged.

4. Intercalary heat exchange according to the preceding claim, such that the second bent portion (46A) is folded by flattening so that the second contact portion (46) has a partial planar appearance.

5. Heat exchange spacer according to claim 3, such that the second bent portion (46A) is folded by an inverse fold so that the second contact portion (46) has a bend appearance.

6. heat exchange spacer according to claim 1 or 2, such that the second bent portion (46A) is folded by several reverse bends so that the second portion (46) of contact has a wave shape.

7. heat exchange spacer according to one of the preceding claim, such that said planar portions

(42) have flow deflectors (56) in the form of metal lamellae (58) projecting from said flat portion (42).

8. Heat exchange spacer according to one of the preceding claims, such that the spacers (40) are made from a strip of aluminum alloy sheet.

A heat exchange device having at least one bundle of first tubes (8) spaced apart from a first gap (II) and a bundle of second tubes (22) spaced apart from a second gap (12), such as it comprises a heat exchange pad as claimed in claims 1 to 8.

10. Heat exchange device according to the preceding claim, such that the first tubes (8) and the second tubes (22) are flat tubes.

11. The heat exchange device according to one of the preceding claims, such that the first tubes (8) are multi-channel tubes (32).

12. Heat exchange device according to one of the preceding claims, as it is composed of a condenser-type heat exchanger (18) comprising the bundle of first tubes (8) and a heat exchanger. Radiator (26) comprising the bundle of associated second tubes (8).

13. Heat exchange device according to one of claims 9 to 11, characterized in that the bundle of first tubes (8) and the bundle of second tubes (22) are part of the same heat exchanger.