Heat exchanger, air-conditioning system and method for manufacturing such a heat exchanger

Abstract

The invention relates to a heat exchanger comprising: - a first exchanger block (10) and a second exchanger block (11) comprising a plurality of internal plates (13), which are arranged substantially parallel to one another, characterized in that it further comprises: - two junction plates (22, 24) arranged between the exchanger blocks (10, 11), each junction plate (22, 24) having two distal ends which each have an end portion configured to be able to extend longitudinally beyond the first exchanger block and the second exchanger block, a first end portion of the first junction plate (22) being configured to be able to be connected to a first end portion of the second junction plate (24); - a damping material (38) selected from the group consisting of metal knits and elastomers arranged between the junction plates (22, 24).

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: HEAT EXCHANGER, AIR CONDITIONING SYSTEM AND METHOD FOR MANUFACTURERING SUCH A HEAT EXCHANGER

[0003] Technical field of the invention

[0004] The invention relates to a plate heat exchanger, in particular for an aerial vehicle, as well as a method for manufacturing such a heat exchanger.

[0005] Technological background

[0006] Heat exchangers are used to allow heat transfer between at least two fluids, separated from each other by plates in contact with which heat exchange takes place in order to cool or heat one fluid using another fluid.

[0007] Plate heat exchangers integrated into atmospheric vehicles are likely to be subjected to significant temperature gradients both during the brazing stage of their manufacture and during operation, across successive operating cycles. This is particularly true, for example, of a heat exchanger designed to cool high-pressure bleed air drawn from an aircraft propulsion engine or an auxiliary power unit (APU).

[0008] Such heat exchangers are also likely to be regularly subjected to vibrations.

[0009] The thermo-mechanical stresses experienced by plate heat exchangers can lead to deformations that may result in cracks or even rupture of certain components. These phenomena create a risk of fluid leakage inside the exchanger, or even to the outside. Large heat exchangers are particularly susceptible to these stresses and are also especially difficult to manufacture.

[0010] For example, US 4 297 775 is known as a method for assembling two plate heat exchanger blocks by placing a layer made of a deformable metal piece between the two heat exchanger blocks.

[0011] However, such a process does not allow for the provision of a heat exchanger with vibration damping properties compatible with its use in an aerial vehicle.

[0012] Objectives of the invention

[0013] The invention aims to provide a heat exchanger and a method for manufacturing such an exchanger to overcome these drawbacks.

[0014] The invention aims in particular to propose a method for manufacturing a large-dimension heat exchanger, in particular one of great height.

[0015] The invention also aims to provide a heat exchanger exhibiting increased thermo-mechanical resistance and excellent vibration damping properties.

[0016] The invention also aims to provide a heat exchanger exhibiting excellent structural cohesion that is stable over time.

[0017] Description of the invention

[0018] To achieve this, the invention relates to a heat exchanger comprising:

[0019] - a circulation enclosure comprising a first inlet of a first fluid into the circulation enclosure and a first outlet of said first fluid outside the circulation enclosure,

[0020] - a second inlet of a second fluid into the circulation chamber and a second outlet of said second fluid out of the circulation chamber,

[0021] - at least one first plate heat exchanger block arranged in said circulation enclosure so as to be in fluid communication with said inlets and said outlets to allow the circulation of the first fluid and the second fluid in and through this heat exchanger block and the transfer of heat between them,

[0022] - at least one second plate heat exchanger block disposed in said circulation enclosure so as to be in fluid communication with said inlets and said outlets to allow the circulation of the first fluid and the second fluid in and through this heat exchanger block and the transfer of heat between them,

[0023] - each heat exchanger block comprising a plurality of plates, called internal plates, arranged substantially parallel to each other, characterized in that it further comprises:

[0024] - a first junction plate and a second junction plate of said first exchanger block and said second exchanger block disposed between said first exchanger block and said second exchanger block, each junction plate having two distal ends each having an end portion configured to be able to extend longitudinally beyond said first exchanger block and said second exchanger block, a first end portion of said first junction plate being configured to be able to be connected to a first end portion of said second junction plate,

[0025] - at least one material, called damping material, chosen from the group consisting of metallic knits, elastomers and their mixtures, arranged between said connecting plates.

[0026] Thus, a heat exchanger according to the invention improves both its thermomechanical behavior and its resistance to vibration by limiting deformations and modal responses. The junction between each heat exchanger block forms a zone of expansion and damping for the heat exchanger. Furthermore, the junction plates are configured to limit the pressure drop associated with the junction between said heat exchanger blocks.

[0027] Advantageously and according to the invention, each end portion of said joining plates is inclined with respect to a main flat portion of each joining plate.

[0028] Advantageously and according to the invention, said first end portion of said first junction plate is configured to be able to be in contact with said first end portion of said second junction plate.

[0029] Advantageously and according to the invention, said heat exchanger comprises two external plates delimiting said circulation chamber and arranged substantially parallel to the internal plates of said first exchanger block and said second exchanger block, said first exchanger block and said second exchanger block being arranged between said external plates.

[0030] Advantageously, and according to the invention, the heat exchanger comprises a plurality of sealing bars arranged between two inner plates, each sealing bar extending primarily in a longitudinal direction. Some sealing bars are also arranged between an inner plate and an outer plate, or between an inner plate and a connecting plate. Each sealing bar is thus configured to be able to at least partially block a circulation layer of one of the first and second fluids in the circulation chamber of the heat exchanger according to the invention.

[0031] Advantageously, and according to the invention, said heat exchanger comprises bundle edges disposed at least partially in contact with said end portions of said junction plates. In particular, notches may be provided in each bundle edge to conform to the protruding portion formed by said end portions of said junction plates.

[0032] The space between each of the plates of said first heat exchanger block and said second heat exchanger block may be left free or fitted with flow guides (or fins). Advantageously, and according to the invention, a heat exchanger according to the invention comprises at least one flow guide disposed between said inner plates (or between an inner plate and an outer plate, or between an inner plate and a junction plate) of the first heat exchanger block and said second heat exchanger block, each flow guide being adapted to form a plurality of circulation channels for said first fluid and / or said second fluid. Thus, in other words, advantageously and according to the invention, each inner layer is fitted with at least one flow guide adapted to form a plurality of substantially parallel channels. The channels formed may, for example, be substantially parallel to each other.

[0033] Advantageously, according to the invention, each flow guide is formed from a plurality of successive sections, each having a serrated profile, so as to form guiding walls and surface contact areas with the plates. These are, for example, so-called "offset" flow guides in which two successive sections are laterally offset, such that the guiding walls of a section located directly adjacent to another section are laterally offset (in a direction parallel to the external plates of the heat exchanger block) relative to the guiding walls of the latter. Each flow guide can be secured to the plates, for example, by brazing or welding.

[0034] The use of such flow guides between the plates of each exchanger block is optional but improves the efficiency of heat exchange.

[0035] A heat exchanger according to the invention can be cross-flow or counter-current (single-pass or multi-pass). Advantageously, according to the invention, the path of the first fluid flow and the path of the second fluid flow within said exchanger blocks can each be substantially straight. Advantageously, according to the invention, said heat exchanger is said to be cross-flow. The heat exchanger according to the invention is adapted to allow the circulation of the second fluid in a second fluid passage, in a direction, called the second fluid flow direction, orthogonal to the principal flow direction of the first fluid.

[0036] It is of course also possible to use any other type of plate heat exchanger block, for example in which the flow of one and / or the other of the first or second fluid follows a U-shaped path or an S-shaped path or a Z-shaped path or any more complex circuit.

[0037] Advantageously and according to the invention, the circulation enclosure has a closed periphery that is sealed against fluids (at least in operation and without taking into account the inlets and outlets for the first fluid and for the second fluid).

[0038] Advantageously, and according to the invention, each fluid can be in liquid or gaseous form. In particular, the state of the first fluid can be the same as or different from the state of the second fluid. Advantageously, and according to the invention, both the first and second fluids are in gaseous form.

[0039] Advantageously, according to the invention, the first inlet has an inlet port for the first fluid into the circulation chamber. Advantageously, according to the invention, the first outlet has an outlet port for the first fluid out of the circulation chamber. In a particularly advantageous embodiment of the invention, each outlet has a single orifice forming an inlet or outlet, an opening to the circulation chamber and / or to the plate heat exchanger block, and a solid peripheral wall between this orifice and this opening. Each orifice of each outlet can be connected to a fluid supply or discharge line.

[0040] The invention also relates to an air conditioning system comprising at least one such heat exchanger.

[0041] The invention also relates to a method for manufacturing such a heat exchanger in which:

[0042] - at least one first heat exchanger block is chosen, comprising a plurality of plates, called internal plates, arranged substantially parallel to each other,

[0043] - at least one second heat exchanger block is chosen, comprising a plurality of plates, called internal plates, arranged substantially parallel to each other,

[0044] - a first junction plate and a second junction plate are arranged between said first exchanger block and said second exchanger block, each junction plate having two distal ends, each having an end portion configured to be able to extend longitudinally beyond said first exchanger block and said second exchanger block, a first end portion of said first junction plate being configured to be able to be connected to a first end portion of said second junction plate,

[0045] - at least one material, called a damping material, chosen from the group consisting of metal knits, elastomers and their mixtures, is placed between said first junction plate and said second junction plate.

[0046] Furthermore, a continuous weld is made between the end portions of said connecting plates in contact with each other. Such a continuous weld improves the sealing of the heat exchanger and helps to limit the deformations and thermomechanical and vibrational stresses experienced by the heat exchanger. Advantageously, and according to the invention, said continuous weld is also made between at least one edge of the bundle and at least one edge of said first heat exchanger block and at least one edge of said second heat exchanger block.

[0047] The heat exchanger according to the invention can comprise different materials and is in particular formed of at least one material selected from metallic materials and their composite materials. In particular, in a particularly advantageous embodiment of a heat exchanger according to the invention, the plates of the exchanger block are formed of metallic material, notably at least one material selected from the group consisting of steels, copper, aluminum, metallic alloys (including superalloys) and mixtures thereof.

[0048] The invention also relates to a heat exchanger, an air conditioning system comprising such a heat exchanger and a method for manufacturing such a heat exchanger characterized in combination by all or part of the characteristics mentioned above or below.

[0049] List of figures

[0050] Other objects, features and advantages of the invention will become apparent from the following description, given by way of non-limiting example only, and which refers to the accompanying figures in which:

[0051] [Fig. 1] is a schematic perspective view of a first exchanger block and a second exchanger block of a heat exchanger according to the invention.

[0052] [Fig. 2] is a schematic side view of the first exchanger block and the second exchanger block of a heat exchanger according to the invention.

[0053] [Fig. 3] is a schematic perspective view of the first and second heat exchanger blocks of a heat exchanger after a step in a manufacturing process according to the invention. Detailed description of an embodiment of the invention

[0054] In the figures, scales and proportions are not strictly to scale for illustrative and clarity purposes. Identical, similar, or analogous elements are designated by the same reference numerals in all figures.

[0055] Figures 1 to 3 illustrate an embodiment of a heat exchanger and a method for manufacturing a heat exchanger according to the invention.

[0056] The heat exchanger includes a circulation chamber delimited by two external plates 14 and 16.

[0057] The heat exchanger includes a first inlet 4 and a first outlet 5 of a first fluid in the circulation chamber, as well as a second inlet 6 and a second outlet (not shown) of a second fluid in the circulation chamber.

[0058] The heat exchanger comprises two heat exchanger blocks 10, 11 placed side by side in a plane parallel to the external plates 14, 16, i.e., a first heat exchanger block 10 and a second heat exchanger block 11 arranged one above the other. Each of the first heat exchanger block 10 and the second heat exchanger block 11 comprises a plurality of internal plates 13 arranged substantially parallel to each other. The internal plates 13 of the first heat exchanger block 10 therefore extend parallel to the internal plates 13 of the second heat exchanger block 11 of the heat exchanger.

[0059] The first heat exchanger block 10 is arranged between the upper outer plate 14 and a first junction plate 22. The second heat exchanger block 11 is arranged between the lower outer plate 16 and a second junction plate 24, as shown in Figures 1 to 3. Each junction plate 22, 24 extends between two distal ends, each having an end portion 25, 26, 27, 28 configured to extend longitudinally beyond the first heat exchanger block and beyond the second heat exchanger block, that is, beyond the longitudinal end of each inner plate 13 of each heat exchanger block. The end portions 25, 26, 27, 28 of the junction plates 22, 24 therefore protrude from a face of the heat exchanger block on the side of which they are positioned. The first junction plate 22 extends between two opposite end portions, that is, between a first end portion 25 and a second end portion 27.Similarly, the second connecting plate 24 extends between two end portions that are longitudinally opposed to each other, that is, between a first end portion 26 and a second end portion 28.

[0060] The first end portion 25 of the first connecting plate 22 can be positioned in contact with the first end portion 26 of the second connecting plate 24, as shown in Figure 2, forming a bearing area 29 corresponding to the edge of each end portion. Similarly, the second end portion 27 of the first connecting plate 22 can be positioned in contact with the second end portion 28 of the second connecting plate 24. Each end portion 25, 26, 27, 28 of the connecting plates 22, 24 is inclined relative to a main flat portion of each connecting plate 22, 24. The end portions of the same connecting plate 22, 24 are inclined (or curved) towards the same side relative to its main flat portion.In the embodiment illustrated in Figures 1 to 3, each end portion 25, 26, 27, 28 of the connecting plates 22, 24 is in the form of a strip whose longitudinal edge is connected to the main portion of the connecting plate and is oriented at a non-zero angle, in particular between 10° and 60°, with respect to the plane in which the flat main portion of the connecting plate extends. It is also permissible to provide any other shape for the end portions of each connecting plate, such as a curved or arched portion, configured to be connected to the end portion of the connecting plate opposite which it is positioned. The two connected end portions of two connecting plates could also be joined together by means of an additional piece.Furthermore, the overall curved shape of the assembled end portions helps to limit the pressure loss at the inlet and outlet of the first fluid by providing an aerodynamic shape.

[0061] The two connecting plates 22, 24 are arranged relative to each other to create a junction layer between the first heat exchanger block 10 and the second heat exchanger block 11. A damping material 38, selected from the group consisting of metal mesh, elastomers, and mixtures thereof, is placed between the connecting plates 22, 24, within this junction layer. In the illustrated embodiment, this material is specifically a knitted metal mesh. This damping material is at least partially deformable or flexible so as to allow for any relative movement of the connecting plates 22, 24 with respect to each other due to the expansion of the materials forming each component of the heat exchanger and / or to the mechanical stresses experienced by the heat exchanger, in particular vibrations causing compressive, tensile, or shear forces within each heat exchanger block 10, 11.Such a damping material 38 helps to improve the thermomechanical behavior and vibration resistance of the heat exchanger. The junction between each exchanger block thus forms a zone of expansion and damping of the heat exchanger.

[0062] As can be seen in Figures 1 to 3, each outer plate 14, 16 extends longitudinally beyond the inner plates 13 of the first exchanger block 10 and the second exchanger block 11, in the same direction as the end portions 25, 26, 27, 28 of the junction plates 22, 24. This facilitates the positioning of beam edges 32, 34 for an inlet 4 and / or outlet of the first fluid. Here, each beam edge 32, 34 includes a notch configured to receive the end portions 25, 26 of the connecting plates 22, 24. Furthermore, a weld 40 (Figures 2 and 3) is made to hermetically seal the outer plates 14, 16, the beam edges 32, 34, two edges of the heat exchanger blocks, and the end portions 25, 26 of the connecting plates 22, 24 together. Such a continuous weld improves the sealing of the heat exchanger.

[0063] The heat exchanger further comprises a plurality of sealing bars 18, 19 arranged between the inner plates 13 so as to laterally seal each circulation layer of the first or second fluid. In the embodiment illustrated in Figures 1 to 3, the sealing bars 18 extend parallel to the main direction of circulation of the first fluid within the exchanger, and the sealing bars 19 extend parallel to the main direction of circulation of the second fluid within the exchanger.

[0064] Fins 15, 17 (or flow guides) are arranged in each circulation layer of the first and second fluids. The fins 15, 17 can be formed from corrugated plates creating circulation channels with various geometries.

[0065] The first fluid, called the "cold" fluid, circulates in the circulation zones of the first fluid along a main direction of circulation of the first fluid between the first inlet 4 and the first outlet 5. The second fluid, called the "hot" fluid, circulates in the circulation zones of the second fluid, distinct from the circulation zones of the first fluid, between the second inlet 6 and the second outlet.

[0066] In the embodiment shown here, the first and second fluids flow in a simple cross-flow configuration. Other flow configurations for the first and second fluids are also possible.

[0067] The number of circulation layers for the first and second fluids in each heat exchanger block 10, 11 is relatively small in the embodiment shown in Figures 1 to 3, for the sake of illustration and clarity. However, each heat exchanger block can, of course, comprise a greater number of internal plates 13 and therefore a larger number of circulation layers, thus allowing for the fabrication of heat exchangers with significant heights. In particular, the first and second heat exchanger blocks do not necessarily have the same number of circulation layers or the same number of internal plates 13. Similarly, the heat exchanger thus fabricated can comprise more than two heat exchanger blocks, each heat exchanger block being joined to a separate heat exchanger block by at least two connecting plates according to the invention.A heat exchanger comprising three exchanger blocks will therefore include two junction zones, each comprising two junction plates according to the invention.

Claims

DEMANDS 1. Heat exchanger comprising: - a circulation enclosure comprising a first inlet (4) of a first fluid into the circulation enclosure and a first outlet (5) of said first fluid out of the circulation enclosure, - a second inlet (6) of a second fluid into the circulation chamber and a second outlet of said second fluid out of the circulation chamber, - at least one first plate heat exchanger block (10) arranged in said circulation enclosure so as to be in fluid communication with said inlets (4, 6) and said outlets (5) to allow the circulation of the first fluid and the second fluid in and through this heat exchanger block and the transfer of heat between them, - at least one second plate heat exchanger block (11) arranged in said circulation enclosure so as to be in fluid communication with said inlets (4, 6) and said outlets (5) to allow the circulation of the first fluid and the second fluid in and through this heat exchanger block and the transfer of heat between them, - each heat exchanger block comprising a plurality of plates, called internal plates (13), arranged substantially parallel to each other, characterized in that it further comprises: - a first junction plate (22) and a second junction plate (24) of said first exchanger block (12) and said second exchanger block (22) disposed between said first exchanger block (10) and said second exchanger block (11), each junction plate (22, 24) having two distal ends each having an end portion (25, 26, 27, 28) configured to be able to extend longitudinally beyond said first exchanger block and beyond said second exchanger block, a first end portion (25, 27) of said first junction plate (22) being configured to be able to be connected to a first end portion (26, 28) of said second junction plate (24), - at least one material, called a damping material (38), chosen from the group formed metallic knits, elastomers and mixtures thereof, arranged between said joining plates (22, 24).

2. Heat exchanger according to claim 1, characterized in that each end portion (25, 26, 27, 28) of said junction plates (22, 24) is inclined with respect to a main flat portion of each junction plate (22, 24).

3. Heat exchanger according to any one of claims 1 or 2, characterized in that said first end portion (25, 27) of said first junction plate (22) is configured to be able to be in contact with said first end portion (26, 28) of said second junction plate (24).

4. Heat exchanger according to any one of claims 1 to 3, characterized in that it comprises two external plates (14, 16) delimiting said circulation chamber and arranged substantially parallel to the internal plates (13) of said first exchanger block and said second exchanger block, said first exchanger block (10) and said second exchanger block (11) being arranged between said external plates.

5. Heat exchanger according to any one of claims 1 to 4, characterized in that it comprises a plurality of closure bars (18, 19) arranged between two internal plates (13), each closure bar (18, 19) extending mainly in a longitudinal direction.

6. Heat exchanger according to any one of claims 1 to 5, characterized in that it comprises bundle edges (32, 34) disposed at least partly in contact with said end portions (25, 26, 27, 28) of said junction plates (22, 24).

7. Heat exchanger according to any one of claims 1 to 6, characterized in that it comprises at least one flow guide (15, 17) disposed between said internal plates (13), each flow guide being adapted to form a plurality of circulation channels for said first fluid and / or said second fluid.

8. Air conditioning system characterized in that it comprises at least one heat exchanger according to any one of claims 1 to 7.

9. A method for manufacturing a heat exchanger according to any one of claims 1 to 7, wherein: - at least one first heat exchanger block (10) is chosen, comprising a plurality of plates, called internal plates (13), arranged substantially parallel to each other, - at least one second heat exchanger block (11) is chosen, comprising a plurality of plates, called internal plates (13), arranged substantially parallel to each other, - a first junction plate (22) and a second junction plate (24) of said first exchanger block (12) and of said second exchanger block (11) are arranged between said first exchanger block and said second exchanger block, each junction plate (22, 24) having two distal ends each having an end portion (25, 26, 27, 28) configured to be able to extend longitudinally beyond said first exchanger block and beyond said second exchanger block, a first end portion (25, 27) of said first junction plate (22) being configured to be able to be connected to a first end portion (26, 28) of said second junction plate (24), - at least one material, called damping material (38), chosen from the group consisting of metal knits, elastomers and mixtures thereof, is placed between said first junction plate (22) and said second junction plate (24).

10. Manufacturing method according to claim 9, wherein a continuous weld (40) is made between the end portions (25, 26, 27, 28) of said joining plates (22, 24) in contact with each other.

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