EP2904344A1

EP2904344A1 - Fin plate, frame comprising at least one such plate and heat exchanger comprising said frame

Info

Publication number: EP2904344A1
Application number: EP12795493.1A
Authority: EP
Inventors: Erick RIGAUDIE; Nicolas GALMICHE; Damien BURATO
Original assignee: Olaer Industries SA
Current assignee: Parker Hannifin Manufacturing France SAS
Priority date: 2012-10-04
Filing date: 2012-10-04
Publication date: 2015-08-12
Anticipated expiration: 2032-10-04
Also published as: WO2014053712A1; CN105209844B; CN105209844A; DK2904344T3; US10337806B2; EP2904344B1; US20150276330A1

Abstract

A fin plate (20) comprises a base (22) and a plurality of heat exchanger fins (30) extending from said base, said fins (30) being distributed in fin strips (34) parallel to each other. According to the invention, two neighbouring fin strips (34) are separated, in a direction perpendicular to the direction of said fin strips, by at least one flat strip having no fins (32). Two fin plates (20) of this type can be assembled to form a frame, in particular suitable for being incorporated into a heat exchanger.

Description

PLATE WITH FINS, ARMATURE COMPRISING AT LEAST ONE SUCH PLATE AND THERMAL EXCHANGER COMPRISING SAID FRAME

Technical area

The present invention relates to the field of heat exchangers.

It relates more particularly to a finned plate, an armature comprising at least one such finned plate and a heat exchanger comprising such a frame.

Background of the invention

Heat exchangers consisting of a stack of heat exchange modules are known today, each module 910 comprising a circulation cell 912 for a fluid to be cooled Fl, in particular a liquid, and a circulation cell 914 for a fluid of cooling F2, for example a gas and in particular air, the two cells being thermally coupled to one another. Such a heat exchange module is illustrated in FIG.

The circulation cell for the fluid to be cooled comprises, to increase the heat exchange surface and increase the efficiency of exchanges with the cooling fluid, a plate 916 comprising a plurality of fins 918 substantially rectangular profile distributed in parallel strips contiguous to each other in a direction perpendicular to the direction of said strips.

Such a finned plate is far from providing satisfactory performance. However, in the context of current environmental concerns, it is necessary, among other things, to optimize the energy efficiency of the apparatus and in particular the heat exchangers, without increasing either their cost or the quantity of materials used for their manufacture.

Object and summary of the invention

The present invention therefore aims at providing a heat exchanger whose thermal and energy performance are optimal, which requires the use of a reduced amount of materials for its manufacture and which, moreover, is inexpensive.

According to a first aspect, the invention relates to a finned plate, comprising a base and a plurality of heat exchange fins extending from said base, said fins being distributed over at least two strips of fins parallel to each other, and characterized in that said two adjacent fin strips are separated, in a direction perpendicular to the direction of said fin strips, by a flat strip devoid of fins.

According to a second aspect, the invention also relates to a reinforcement, in particular adapted to be integrated in a heat exchanger, which reinforcement comprises two finned plates as defined above, nested so that the fins of the first finned plate fit in spaces defined opposite said flat strips of the second finned plate and are arranged head to tail relative to the adjacent fins of the second finned plate.

Throughout the present application, the lateral direction of a finned plate is defined as the direction in which the fin strips of this finned plate extend.

In the same way, the longitudinal direction of a finned plate is defined as the direction which is both perpendicular to said lateral direction and parallel to the plane of the base of the finned plate also called "base plane".

Finally, the transverse direction of the finned plate is defined as the direction perpendicular to the base plane.

Unless otherwise indicated, throughout the present application, a length relative to a finned plate or part of a finned plate is measured in the longitudinal direction, a width is measured in the lateral direction, and a thickness or height is measured in the transverse direction.

In a finned plate as defined above, a flat strip separating two adjacent strips of fins, in a direction perpendicular to the direction of said strips of fins, is defined like a band without fins, extending in the plane of the base.

According to an advantageous example of the invention, such a flat strip has a width at least equal to that of a strip of fins.

Generally, the widths of the different strips of fins of the same finned plate are indeed identical.

Generally, in addition, each flat strip extends over the entire length of the fin strips.

According to one embodiment of the invention, a finned plate as defined above may be formed in one piece or in several sections assembled or arranged one after the other.

According to one embodiment of the invention, each fin has two distinct ends integral with the base, the fin portion defined between said ends being a single continuous piece not merged with said base. It will be understood that the lateral direction of a finned plate is generally parallel to the alignment direction of the two ends of the same fin.

In one example, the base has openings between the respective ends of each fin.

According to an advantageous arrangement of the invention, each heat exchange fin has at least one oblique portion relative to the base or a curved portion. In other words, each fin has at least one portion that is neither parallel nor perpendicular to the base plane of the fin plate.

Preferably, the fin has two oblique portions or curves inclined in opposite directions, extending from the base of the finned plate. Such a configuration gives the fin a certain elasticity or flexibility in the transverse direction of the finned plate. It has been demonstrated that such flexibility of the fins allows the use of a smaller amount of material than in the prior art, the plate used to make a finned plate according to the invention may have a low thickness. This provision therefore also has environmental and economic benefits.

According to an exemplary embodiment, each fin has a trapezoidal profile devoid of right angle. Each side of the trapezoid can for example, to be inclined with respect to the base plane by an angle of between 20 ° and 70 °, and preferably equal to 45 °. This example is not, however, limiting, and the fins may have any other shape giving them a certain elasticity in the transverse direction, including partially or fully curved shapes.

Preferably, each fin has a plane of symmetry perpendicular to the lateral direction of the finned plate comprising said fin.

Advantageously, two adjacent fins of two adjacent strips of fins are offset relative to each other in the direction of said strips of fins. For this, two neighboring strips of fins are for example offset relative to each other in the direction of said bands (i.e. the lateral direction).

The value of the offset of the fins that meets the fluid allows optimal heat exchange.

According to a first example, two neighboring strips of fins are separated by a continuous flat strip extending over the entire length of said strips of fins.

In a second example, two neighboring strips of fins are separated by a discontinuous flat strip formed of a succession of segments interspersed with openings. Preferably, each flat band segment is associated and attached to a respective fin of an adjacent fin strip.

According to the first example, the base is a metal plate in which the fins are made by stamping-cutting.

In a second example, the base is a metal plate in which the fins are made by cutting-folding. With this method, the thickness of the plate remains substantially constant.

According to one example, in the armature according to the invention, two adjacent strips of fins, respectively belonging to the two fin plates, are offset relative to each other in the direction of said strips of fins.

According to one example, two portions of fins of the same orientation are aligned in a direction perpendicular to the fin strips and parallel to the bases of the finned plates (ie in the direction longitudinal), all K fin bands, K being an integer greater than 2, preferably equal to 4.

K corresponds to what will be called in the following the periodicity, that is to say the frequency of occurrence in the longitudinal direction Y.

In the following, unless otherwise indicated, the offset will be considered in the lateral direction.

The periodicity and the offset value of the fins encountered by the fluid flowing through the frame allows optimal heat exchange.

According to a third aspect, the invention also relates to a heat exchanger comprising a stack of heat exchange modules, each module comprising a circulation cell for a fluid to be cooled and a circulation cell for a cooling fluid contiguous and thermally coupled. to one another, the circulation cell for the fluid to be cooled and / or the circulation cell for the cooling fluid comprising a reinforcement as defined above.

According to one example, to ensure tightness, each circulation cell housing an armature comprises at least two spacers each comprising a first support face and a second opposite parallel support face adapted to come into contact with the respective bases of the two. wing plates of said frame.

According to an example, the distance separating the two bearing faces of each spacer is less than the height of the heat exchange fins. When the armature is mounted between two spacer plates spaced from each other by said spacers, the fins are elastically deformed, because of their relative flexibility in the transverse direction, so as to ensure permanent contact with said separator plates and therefore an effective heat exchange.

Several modes and examples of implementation are described in this paper. However, unless otherwise specified, the features described in connection with any mode or example may be applied to another mode or example of implementation.

Brief description of the drawings The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of several embodiments shown by way of non-limiting examples. The description refers to the accompanying drawings in which:

FIG. 1 illustrates a heat exchange module of the prior art,

FIG. 2 is an overall view of a heat exchanger according to one embodiment of the invention,

FIG. 3 is an exploded view of a heat exchange module contained in the exchanger of FIG. 2;

- Figures 4 and 5 are partial perspective views of a finned plate according to a first embodiment, respectively from above and from below,

FIG. 6 illustrates the finned plate of FIGS. 4 and 5 in plan view,

FIGS. 7A and 7B show an armature according to the first embodiment of the invention, in front view,

FIG. 8 shows in more detail the arrangement of the fins in the frame of FIGS. 7A and 7B,

FIG. 9 illustrates the armature of FIG. 8 in plan view,

FIG. 10 is a view in partial section of the armature of FIG. 8,

FIG. 11 shows an armature according to a second embodiment of the invention, in perspective,

- Figure 12 shows the armature of Figure 11, in front view.

Detailed description of several embodiments

FIG. 2 shows a heat exchanger 80 according to one embodiment of the invention, comprising a plurality of heat exchange modules 10 stacked in a transverse direction ZI.

The stack is here surrounded by a frame 82 comprising two longitudinal sides 84a, 84b provided with fixing means 85, and two other sides 86a, 86b extending in the transverse direction ZI and respectively defining an inlet manifold CE provided with at least one entry 88 and an outlet manifold CS provided with at least one outlet 90 for a fluid to be cooled.

In the illustrated example, each heat exchange module 10 comprises a cell for the circulation of said fluid to be cooled (hereinafter also the first circulation cell) extending in the longitudinal direction Y1 of the heat exchanger 80 from the collector CE input to the CS output manifold.

Each module 10 further comprises a cell for the circulation of a cooling fluid (hereinafter also second circulation cell), opening outwards at its two ends, opposite in the lateral direction of the exchanger.

As illustrated in FIG. 3, each first circulation cell is delimited by a first and a second separation plate 70, 72, spaced apart by a first pair of spacers 60a, 60b. An armature 16 (see FIGS. 7A and 7B) according to the present invention comes to fill the interior space defined between these different elements.

Each second circulation cell is delimited by a second pair of spacers 78 (only one is shown in FIG. 3), and houses a block of fins 74.

The various elements of the heat exchange module 10 can be fixed to each other by welding and / or brazing techniques known per se and not detailed here.

Note that the heat exchanger of the example in question is not limiting of the present invention. Thus, an exchanger according to the invention may have any other suitable configuration. For example, the fluid to be cooled and the cooling fluid can circulate along paths that are no longer perpendicular but parallel, in opposite directions or in the same direction.

An armature 16 according to the invention, intended, as indicated above, to be placed in a circulation cell of a heat exchange module, will now be described in more detail.

Such an armature 16 consists of two similar plates 20 (hereinafter wing plates) nested one inside the other. To understand the structure of the armature 16, it is therefore necessary to first describe one of these fin plates 20. This is what will be done in the following with reference to Figures 4 and 5.

As illustrated in Figure 4, a fin plate 20 has a base 22 of generally rectangular shape defined in a base plane PB.

The lateral direction X of the finned plate 20 is defined for the following, in which extend its short sides 24a, 24b, its longitudinal direction Y, in which extend its long sides 26a, 26b, and finally its transverse direction. Z, normal to the basic plane PB. To simplify the representation, only a portion of the plate 20 is shown in Figures 4 and 5. As indicated by the dashed lines, the plate continues identically in the longitudinal direction Y.

Referring to the heat exchanger 80 of FIG. 2, the longitudinal direction Y of a finned plate 20 included in this exchanger is parallel to the longitudinal direction Y1 of the exchanger 80. In the same way, the lateral direction X of the finned plate 20 is parallel to the lateral direction XI of the exchanger 80. Finally, the transverse direction Z of the finned plate is parallel to the transverse direction ZI of the exchanger 80.

As illustrated in FIG. 5, the base 22 has a plurality of substantially rectangular openings 28 arranged in parallel rows oriented in the lateral direction X. With reference to FIG. 4, it will be understood that each of these openings is overhanging by a fin 30 extending from the base 22 in the transverse direction Z.

Each fin 30 is here a continuous piece not confused with the base but connected thereto by two ends.

In other words, the finned plate 20 comprises a plurality of corrugated strips or strips of fins 34, separated from each other by continuous flat base strips 32, here of the same width (measured in the longitudinal direction Y of the plate) and extending over all or substantially the entire width of the plate. As is apparent from Figures 4 and 5, all the fins 30 project from the same side of the fin plate, the opposite side remaining generally plane. Such a plate 20 is for example obtained by simultaneously punching and stamping a flat sheet.

Within the same band of fins 34, two adjacent fins 30 are separated from each other by a portion coinciding with the base 22 and said intermediate portion 36.

As is apparent from Figure 4, the fins 30 have almost all the same isosceles trapezoidal profile.

Each comprises a first oblique wall 42 and a second oblique wall 44 inclined in opposite direction to the first, connected via a junction portion 40 parallel to the base plane PB and spaced from said plane PB by a predetermined distance d1 corresponding to the total thickness of the fin plate 20. In the illustrated example, the oblique walls 42, 44 are both inclined at an angle de of 45 ° with respect to the base plane PB. In addition, the junction portion 40 here has the same length as the intermediate portion 36 above.

According to one aspect of the invention, two fins plates 120, 220 similar and in accordance with that described above are assembled to form a frame 16 of the type illustrated in Figures 7A, 7B and 8. The elements already described by reference to the fin plate 20 have the same reference numbers in Figures 6 to 10, optionally incremented by 100 or 200 according to that of the two finned plates 120, 220 which is referred to.

In FIG. 6, which illustrates such a plate 120 in plan view, it is observed that the blades of fins of rank 2N (N being an integer) have an identical configuration. Each fin of each band of wings of rank 2N is in particular aligned, in the longitudinal direction Y, with a fin of each other band of rank 2N.

In the same FIG. 6, it can be seen that the blades of fins of rank 2N + 1 (N being an integer) are all shifted with respect to the bands of rank 2N, in the lateral direction X.

This offset, in the lateral direction X, between the rank 2N and rank 2N + 1 bands, is here equal to a quarter of the length L of a fin, measured in the same lateral direction X. It is observed, again by observing FIG. 6, that all the bands of rank 2N have the same length, greater than that of the bands of rank 2N + 1. In the example, the rank 2N strips comprise, in fact, a fin portion 50 in addition, at one of their ends. Each of these fin parts is folded towards the base plane according to a triangular profile 50, as illustrated in FIG. 4. From FIG. 6, it is further apparent from said fin portion has a length equal to L / 2. in other words half the length of a fin.

Finally, two immediately adjacent wings of rank 2N and 2N + 1 are spaced, in the longitudinal direction Y, by a distance at least equal to the width of a strip of fins in this direction Y.

The aforementioned configuration is such that two finned plates 120, 220 of the aforementioned type can be arranged head to tail to form a frame 16.

In this position, the first large side 126a of the first finned plate 120 is disposed opposite the second major side 226a of the second plate 220, and the second major side 126b of the first finned plate 120 is opposite the first major 226b side of the second plate 220 (see Figure 3).

On the other hand, the joining portions 140 of the fins 130 of the first finned plate 120 are opposite the flat strips 232 of the second finned plate 220, and vice versa.

The configuration obtained is illustrated by FIGS. 7A, 7B, 8, 9 and

10.

With reference to FIG. 9, considering either the fin strips of the two finned plates, the fins of the 4N rank strips are aligned with each other in the longitudinal direction Y, as are the fins of the rank strips. 4N + 1 shifted with respect to the fins of the 4N rank strips by a distance L / 4 in the lateral direction X, that the fins of the rank 4N + 2 strips offset with respect to the fins of the rank 4N strips by a distance L / 2, and that the fins of the rank 4N + 3 strips offset relative to the fins of the 4N rank strips by a distance 3L / 4.

In FIGS. 8 and 10 in particular, it appears that fin branches of the same orientation appear in the longitudinal direction Y, with a periodicity of 4. In other words, two portions of fins of the same orientation are aligned in the longitudinal direction Y, all 4 strips of fins. In the figure, the distance separating two successive wing branches of the same orientation, in the longitudinal direction Y, is denoted by D, and D is here equal to 3 times the width of a strip of fins.

In other words, a fluid F passing through the armature 16, in the longitudinal direction Y, successively encounters (if we consider portions of the width of a band of fins) a fin, then nothing, nothing, nothing, a fin, nothing, nothing, nothing, a fin, etc.

In other words, a sheet of fluid of the same cross section as a fin and flowing along F passes closer to the fins of rank 4N in this longitudinal direction Y.

Such arrangements make it possible to reduce considerably the pressure losses inside the armature 16 compared to the devices of the prior art which operate in "on-off" mode, that is to say with a periodicity of 2. In these known devices, in fact, the fluid is in contact with fins on half of its path. But the fins form a significant brake to the flow, causing a loss of pressure of the fluid. The amount of energy to be used for the same output is thus much greater.

According to other exemplary embodiments of the invention, the periodicity of the fins inside the armature 16 may be different from 4, and in particular greater than 4. The offset value of the fins may also be chosen according to fluids concerned.

From Figure 7A, it appears that the two finned plates 120, 220 are held in position, inside the heat exchange module 10, by means of two spacers 60a, 60b sandwiched between said plates.

As illustrated in FIG. 3, each spacer 60a, 60b is in the form of an elongate element comprising a first opposite support face 63 and a second opposite support face 64, spaced apart from one another. a distance d3. These two bearing faces have a length L1 substantially equal to the length of the heat exchanger 80 in which the armature 16 must be integrated (see 2), and a width 12 sufficient to ensure good support of the bases of the first and second fin plates.

The two bearing faces 63, 64 of a spacer 60a, 60b are connected by a V-shaped side, intended to be directed towards the inside of the fluid circulation cell. The faces 61, 62 forming the V-shaped profile are inclined relative to the bearing faces 63, 64 of the spacer by an angle equal to the angle of inclination z of the fin walls 42, 44, c '. that is to say here 45 °. The side 65 opposite the V-shaped profile extends perpendicularly to the two bearing faces 63, 64.

In the illustrated example, each fin plate 20 has, at each of its lateral ends 126a, 126b, 226a, 226b an edge respectively 125a, 125b, 225a, 225b folded perpendicularly to the base 22 and of constant height over the entire width of the finned plate 20.

Each folded edge 125a, 125b, 225a, 225b is pressed against the side 65 of a spacer 60a, 60b. Preferably, the height of the folded edges of each finned plate is chosen to be less than at least half the thickness d3 of the spacer, so that the respective edges of the two finned plates 120, 220 opposite do not overlap.

It is recalled that the assembly formed by the spacers 60a, 60b and the finned plates 120, 220 is mounted between two separating plates 70, 72 as previously described in connection with FIG. 4.

The shape of the fins and in particular their oblique walls 42, 44 give them a relative elasticity, which makes it possible to reduce the dimensional constraints during assembly between the separating plates 70, 72. In the case where the height of the fins is initially slightly greater than the thickness of the struts 60a, 60b, the oblique parts of the fins flex when the plates 70, 72 are brought closer to each other until they come into contact with the bearing faces of the struts.

An armature 116 according to a second embodiment of the present invention will now be described with reference to Figures 11 and 12.

FIG. 11 illustrates two finned plates 320, 420 according to this second embodiment, nested one inside the other of the same in the preceding mode, and forming a reinforcement 116. The elements already described with reference to the finned plates 20, 120, 220 have the same reference numerals as in Figures 6 to 10, optionally incremented by 100 or 200 depending on the two finned plates 320, 420 which is in question.

Unless otherwise specified, all the arrangements described above with the first embodiment of Figures 2 to 10 remain applicable to this second embodiment.

Each vane plate 320, 420 is characterized in that two adjacent vane strips of the same plate are separated by a discontinuous flat strip 332, 432 formed by an alignment of flat segments 333, 433 alternated with openings 337, 437 As illustrated in FIG. 11, the segments 333, 433 generally have a length L5 substantially equal to that L4 measured between two intermediate portions 336, 436 of a strip of fins.

Note also that the flat segments 333, 433 of adjacent rows are offset relative to each other, to account for the offset fins, described in connection with the first embodiment and not repeated here.

Such a finned plate 320, 420 is obtained by cutting a metal plate and then folding to obtain the fins. Unlike the previous embodiment, no stamping operation is necessary.

As illustrated in FIGS. 11 and 12, once the two finned plates 320, 420 are nested one inside the other, the fins 430 of the second finned plate 420 are positioned facing the flat strips 332 of the first finned plate 320, the joining portion 440 of each fin 430 of the second plate 420 being placed between two band segments 333 of the first plate 320, in an opening 337.

In the same way, the fins 330 of the first finned plate 320 are positioned facing the flat strips 432 of the second finned plate 420, the joining portion 340 of each fin 330 of the first plate 320 being placed between two segments 433 of the second plate 420, in an opening 437. In FIG. 12, the armature 116 is shown mounted between two separating plates 70, 72 of the type shown in FIG.

It is found that, unlike the first embodiment described above, the separator plates 70, 72 are directly in contact with the spacers 60a, 60b.

It is further noted that once the armature 116 mounted between the two plates 70, 72, the fins of the two wing plates have been slightly compressed in the transverse direction Z, so that the joining portions 340, 440 of the fins , positioned in the openings 337, 437 as indicated above, are respectively in abutment against the second separator plate 72 and the first separator plate 70. For a better energy efficiency of the assembly, the intermediate portions 336, 436 and / or the joining portions 340, 440 may be attached to the connecting plates against which they are respectively supported, in particular by soldering or welding.

Claims

A fin plate (20, 120, 220, 320, 420) comprising a base (22) and a plurality of heat exchange fins (30) extending from said base (22), said fins (30). being distributed over at least two fins strips (34) parallel to each other, characterized in that said two adjacent strips of fins (34) are separated in a direction perpendicular to the direction (X) of said fins strips ( 34), by a flat strip (32) without fins.

The fin plate (20, 120, 220, 320, 420) according to claim 1, wherein said flat strip (32) has a width at least equal to that of a strip of fins (34).

3. Wing plate (20, 120, 220, 320, 420) according to claim 1 or 2, wherein each fin (30) has two distinct ends integral with the base (22), the fin portion defined between said ends being a single continuous piece not confused with said base (22).

The fin plate (20, 120, 220, 320, 420) according to any one of claims 1 to 3, wherein each heat exchange fin (30) has at least one oblique portion (42, 44) per relative to the base (22) or a curved portion.

The fin plate (20, 120, 220, 320, 420) according to any one of claims 1 to 4, wherein two adjacent fins of two adjacent fins strips (34) are offset relative to each other. the other in the direction (X) of said fin strips (34).

A fin plate (20, 120, 220) according to any one of claims 1 to 5, wherein two adjacent strips of fins (34) are separated by a continuous flat strip (32) extending over the entire length of said fin strips (34).

The fin plate (320, 420) according to any one of claims 1 to 5, wherein two adjacent fin strips are separated by a discontinuous flat strip (332, 432) formed of a succession of segments (333). , 433) interspersed with apertures (337, 437).

8. Reinforcement (16, 116), especially adapted to be integrated in a heat exchanger, comprising two finned plates (20, 120, 220, 320, 420) according to any one of claims 1 to 7 nested so that the fins of the first finned plate (120, 320) fit into spaces opposite said flat strips of the second finned plate (220, 420) and are arranged head-to-tail relative to the adjacent fins of the second finned plate (220, 420).

The reinforcement (16, 116) according to claim 8, wherein two adjacent fin strips, respectively belonging to the two finned plates (120, 220, 320, 420), are offset with respect to each other. in the direction (X) of said fin strips (34).

An armature (16, 116) according to claim 8 or 9, wherein two fin portions of the same orientation are aligned in a direction perpendicular to the fin strips and parallel to the bases of the finned plates, all fins, K being an integer greater than 2, preferably 4. ll. A heat exchanger (80) comprising a stack (11) of heat exchange modules (10), each module (10) comprising a circulation cell for a fluid to be cooled (12) and a circulation cell for a cooling fluid ( 14) contiguous and thermally coupled to each other, the circulation cell for the fluid to be cooled (12) and / or the circulation cell for the cooling fluid comprising an armature (16, 116) according to one of any of claims 8 to 10.