HEAT EXCHANGE DEVICE WITH OUTER PLATES WITH AT LEAST ONE HOLLOW, AIR CONDITIONING AND VEHICLE

Description

Technical field of the invention

[0001] The invention relates to a heat exchange device, in particular a heat exchanger for an aircraft, comprising external plates having at least one recess.

[0002] The invention relates in particular to a plate heat exchange device, two different heat transfer fluids circulating between said plates so as to cool or heat a first fluid with the help of a second fluid, the two fluids being separated from each other by plates in contact with which said heat exchange takes place.

[0003] Plate heat exchangers integrated into atmospheric vehicles are likely to be subjected to significant temperature gradients during their 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).

[0004] When a heat exchanger begins operating and is supplied with bleed air, the temperature of the internal elements of the heat exchanger block (also called the "core") rises more rapidly than that of the adjacent elements of the heat exchanger block and its periphery. This results in temperature gradients that cause mechanical stresses and, consequently, potential deformations of the heat exchanger elements (for example, rotation of the heat exchanger block's closing bars). Such deformations can even lead to the failure of certain elements, manifesting as cracks or debonding of brazed parts. These phenomena create a risk of fluid leakage inside the heat exchanger, or even to the outside. Technological background

[0005] To combat the effects of temperature gradients within the heat exchange devices of atmospheric vehicles, and particularly aircraft, it is known to increase the thickness of the elements of the heat exchanger block most susceptible to breakage and fluid leakage. A heat exchange device according to the preamble of claim 1 is shown in US patent 6,267,176 B1.

[0006] Such a device does not allow for a satisfactory increase in the thermo-mechanical resistance of a heat exchange device to temperature gradients.

[0007] This solution contributes to a significant increase in the mass of the exchanger and is neither desirable nor sufficiently effective in practice.

[0008] The invention therefore aims to provide a heat exchange device to overcome these drawbacks. Objectives of the invention

[0009] The invention aims to provide a heat exchange device exhibiting very low sensitivity to temperature gradients.

[0010] The invention aims in particular to provide a heat exchange device exhibiting excellent structural cohesion that is stable over time.

[0011] The invention also aims to provide a heat exchange device with excellent efficiency. Description of the invention

[0012] To achieve this, the invention relates to a heat exchange device comprising: a circulation chamber delimited by at least two external plates, a first inlet of a first heat transfer fluid into the circulation chamber, a first outlet of said first heat transfer fluid outside the circulation chamber, a second inlet of a second heat transfer fluid into the circulation chamber, a second outlet of said second heat transfer fluid outside the circulation chamber, a plate heat exchanger block disposed in the circulation chamber so as to be in fluid communication with the inlets and outlets to allow the circulation of the first heat transfer fluid and the second heat transfer fluid in and through this heat exchanger block and the transfer of heat between them, said heat exchanger block comprising a plurality of internal plates disposed substantially parallel to each other, characterized in that each external plate has at least one recess.

[0013] Thus, each recess in the external plates facilitates heat conduction from the inside of the heat exchanger block to its exterior via these recesses. A heat exchange device according to the invention therefore limits temperature differences within such a heat exchanger and the resulting stresses. This results in greater mechanical resistance to thermo-mechanical conditions. This, in turn, prevents the breakage of certain components of the heat exchanger assembly.

[0014] Throughout the text, "external plate" means any plate having at least one main face that is not in contact with the first heat transfer fluid and the second heat transfer fluid circulating inside the heat exchanger block, in said circulation enclosure.

[0015] Furthermore, the term "recess" in each outer plate refers to any at least partial recess in the thickness of said plate (for example, a reduction in thickness or a thinning) as well as any through or through opening in the thickness of said outer plate. According to the invention, at least one inner plate of said heat exchanger block is attached to each outer plate so as to prevent any leakage of the first heat transfer fluid and / or the second heat transfer fluid through said recess.

[0016] Advantageously and according to the invention, each external plate has at least one through opening (depending on its thickness).

[0017] Advantageously, and according to the invention, a heat exchange device according to the invention further comprises a plurality of protruding elements configured to be in contact with said first heat transfer fluid and / or said second heat transfer fluid on the surface of a component of said heat exchange device. In particular, advantageously, and according to the invention, each protruding element is formed of at least one material having a thermal conductivity and a volumetric heat capacity at least equal to the thermal conductivity and volumetric heat capacity of the material forming said internal plates of the heat exchanger block.

[0018] Advantageously, and according to the invention, a heat exchange device according to the invention further comprises at least one beam edge arranged to form at least one edge of the exchanger block, each beam edge having a plurality of protruding elements, said protruding elements being configured to be in contact with at least one of said first heat transfer fluid and second heat transfer fluid (i.e., in contact with said first heat transfer fluid and / or said second heat transfer fluid). According to a particularly advantageous embodiment, said protruding elements are configured to be in contact with said second heat transfer fluid either before said second inlet of the circulation chamber or after said second outlet of the circulation chamber. Thus, each protruding element provided on each beam edge makes it possible to locally increase the temperature of the areas in which said protruding elements are located.

[0019] Advantageously and according to the invention, said protruding elements can also be provided on each external plate, said protruding elements being configured to be able to be in contact with said first heat transfer fluid and / or said second heat transfer fluid.

[0020] Advantageously, and according to the invention, each beam edge has at least one recess. Thus, as an alternative or in combination with the presence of protruding elements, a device comprises at least one beam edge arranged to form at least one edge of the heat exchanger block, each beam edge having at least one recess.

[0021] Advantageously and according to the invention, each beam edge is arranged to form at least one edge of the exchanger block, said edge extending in a direction orthogonal to said external plates.

[0022] The second heat transfer fluid can be the fluid whose temperature is higher than that of the first heat transfer fluid, or vice versa. Thus, advantageously and according to the invention, the second heat transfer fluid is the fluid whose temperature is higher than that of the first heat transfer fluid. In other words, the first heat transfer fluid can be designated as the "cold" fluid and the second heat transfer fluid as the "hot" fluid.

[0023] Advantageously, according to the invention, each beam edge extends between two longitudinal ends, with the protruding elements being arranged on end portions of each beam edge. These protruding elements are in the form of protrusions extending from a surface portion of an end portion of the beam edge and may have various geometric shapes. For example, these protruding elements may be in the form of fins, ribs, tabs, studs, pins, teeth, or nipples.

[0024] Advantageously and according to the invention, a heat exchange device according to the invention further comprises at least one box, called a supply box, forming a solid peripheral wall between an orifice and said circulation chamber, each supply box comprising an internal surface having a plurality of protruding elements, said protruding elements being configured to be able to be in contact with said first heat transfer fluid and / or said second heat transfer fluid.

[0025] Advantageously and according to the invention, said protruding elements are at least partly in the form of ribs.

[0026] Advantageously and according to the invention, said protruding elements are at least partly in the form of studs.

[0027] Advantageously and according to the invention, said protruding elements are at least partly in the form of portions of conduits.

[0028] Advantageously, according to the invention, the protruding elements of a beam edge and the beam edge itself are formed from a single piece. They can therefore also be made of the same material. The protruding elements can also be attached, for example, by welding or brazing to the beam edge.

[0029] Advantageously, according to the invention, an internal plate, called an interlayer plate, is positioned in contact with each external plate, between the internal plates of the heat exchanger block and said external plate. Thus, the heat transfer fluid circulating in the first or last layer of the heat exchanger block in contact with said external plates does not escape through any openings in said external plates.

[0030] The space between each of the internal plates of the heat exchanger block, forming internal layers, may be left free or at least partially equipped with flow guides. Advantageously, and according to the invention, a heat exchange device according to the invention further comprises at least one flow guide disposed between each internal plate of said heat exchanger block, each flow guide being adapted to form a plurality of substantially parallel channels. Advantageously, and according to the invention, each internal layer is equipped with at least one flow guide adapted to form a plurality of substantially parallel channels.

[0031] Advantageously, according to the invention, each flow guide is formed of a plurality of successive sections, each having a serrated profile, so as to form guide 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 guide 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 guide walls of the latter.

[0032] Each flow guide can be secured to the inner plates, for example, by brazing or welding. Each flow guide can be secured to the outer plates by a plurality of surface contacts. More specifically, the contact areas (external and internal) of each flow guide are advantageously brazed to the inner faces of one inner plate and the first or second inner plate (end plates).

[0033] The use of such flow guides between the internal plates of the heat exchanger block is optional but improves heat exchange efficiency. Grooved internal plates can also be used.

[0034] Advantageously, and according to the invention, the heat exchange device according to the invention comprises: a first passage, called the first heat transfer fluid passage, allowing the circulation of a flow of the first heat transfer fluid in the circulation chamber between the first inlet and the first outlet, and a second passage, called the second heat transfer fluid passage, allowing the circulation of a flow of the second heat transfer fluid in the circulation chamber between the second inlet and the second outlet.

[0035] Advantageously and according to the invention, said exchanger block is adapted to allow the circulation of a first flow of heat transfer fluid in said circulation chamber in a direction, called the main direction of circulation of the first fluid, between the first inlet and the first outlet.

[0036] A heat exchange device according to the invention may be cross-flow or counter-flow. Advantageously, according to the invention, the path of the first heat transfer fluid flow and the path of the second heat transfer fluid flow within the heat exchanger block may each be substantially straight. Advantageously, according to the invention, said heat exchange device is said to be cross-flow. The heat exchange device according to the invention is adapted to allow the circulation of the second heat transfer fluid in the second heat transfer fluid passage, in a direction, referred to as the second fluid flow direction, orthogonal to the principal flow direction of the first fluid.

[0037] 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 heat transfer fluid follows a U or S path.

[0038] Advantageously and according to the invention, the first heat transfer fluid and the second heat transfer fluid circulate in the spaces between the internal plates closed laterally by closing bars (or rods).

[0039] Advantageously and according to the invention, the circulation enclosure has a closed periphery that is sealed against heat transfer fluids (at least in operation and without taking into account the inlets and outlets for the first heat transfer fluid and for the second heat transfer fluid).

[0040] Advantageously, and according to the invention, each heat transfer fluid can be in liquid or gaseous form. In particular, the state of the first heat transfer fluid can be the same as or different from the state of the second heat transfer fluid. Advantageously, and according to the invention, both the first and second heat transfer fluids are in gaseous form.

[0041] Advantageously, according to the invention, the first inlet has an inlet port for the first heat transfer fluid into the circulation chamber. Advantageously, according to the invention, the first outlet has an outlet port for the first heat transfer fluid outside 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 supply or discharge line for the first heat transfer fluid.

[0042] The heat exchange device according to the invention can be made of at least one material selected from metallic materials, composite materials, polymer materials, ceramic materials, including graphite, glass, etc. In particular, in a particularly advantageous embodiment of a heat exchange device according to the invention, the external and internal plates of the exchanger block are made of metallic material, including at least one material selected from the group consisting of steels, copper, aluminum, metal alloys (including superalloys), and mixtures thereof. In particular, the bundle edges and their protruding elements are made of at least one heat-conducting material, that is, a material having sufficient thermal conductance.

[0043] The invention extends to an air conditioning system comprising at least one heat exchange device according to the invention. This may in particular be a non-contact cross-flow heat exchanger.

[0044] The invention extends to a vehicle, in particular an aircraft, comprising at least one air conditioning system according to the invention.

[0045] The invention also relates to a heat exchange device, an air conditioning system and a vehicle comprising at least one such air conditioning system characterized in combination by all or part of the characteristics mentioned above or below. List of figures

[0046] 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: [ Fig. 1] is a schematic perspective view of a heat exchange device according to the invention, [ Fig. 2 ] is a schematic perspective view of a heat exchanger block of a heat exchange device according to the invention, [ Fig. 3 ] is a schematic perspective view of a portion of a heat exchange device according to the invention, [ Fig. 4 ] is a schematic perspective view of a portion of a heat exchange device according to the invention, [ Fig. 5 ] is a schematic perspective view of a portion of a power supply box of a heat exchange device according to the invention, [ Fig. 6 ] is a schematic perspective view of a portion of a power supply box of a heat exchange device according to the invention, [ Fig. 7 ] is a schematic perspective view of a beam edge of a heat exchange device according to a first embodiment of the invention, [ Fig. 8] is a schematic perspective view of a detail of a beam edge of a heat exchange device according to the first embodiment of the invention, [ Fig. 9 ] is a schematic perspective view of a detail of a beam edge of a heat exchange device according to a second embodiment of the invention. Detailed description of an embodiment of the invention

[0047] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0048] In addition, identical, similar or analogous elements are designated by the same references in all figures.

[0049] There figure 1 schematically illustrates a heat exchange device according to a first embodiment of the invention.

[0050] There figure 2schematically illustrates a heat exchanger block 12 of the heat exchange device according to the first embodiment of the invention shown in figure 1 .

[0051] Such a heat exchange device includes a circulation chamber delimited by two external plates 14 and 16, the exchanger block comprising internal plates 13, 15, 18 arranged substantially parallel to each other between the external plates 14, 16.

[0052] The heat exchange device includes a first inlet 4 and a first outlet 6 of a first heat transfer fluid in the circulation chamber, as well as a second inlet 8 and a second outlet 10 of a second heat transfer fluid in the circulation chamber.

[0053] The 12 plate heat exchanger block therefore allows the circulation of the first heat transfer fluid and the second heat transfer fluid in and through this heat exchanger block and the transfer of heat between them.

[0054] The first heat transfer fluid, called the "cold" fluid, circulates in the circulation zones of the first heat transfer fluid according to a main direction of circulation of the first fluid between the first inlet 4 and the first outlet 6. The second heat transfer fluid, called the "hot" fluid, circulates in the circulation zones of the second heat transfer fluid, distinct from the circulation zones of the first heat transfer fluid, between the second inlet 8 and the second outlet 10.

[0055] As can be seen on the figures 1 and 2The outer plate 14 has at least one recess 20. In the illustrated embodiment, the outer plate 14 has four recesses 20, three of which are oblong openings. Each recess 20 is a through-opening located within the thickness of the outer plate. The openings (or openings) are positioned so as not to extend to the edges and corners of the outer plates. The openings are preferably located in a substantially central area of ​​each plate. As can be seen in the figure 1An internal plate of the heat exchanger block is attached to each external plate 14, 16 (on the inner side of the heat exchanger block), preventing any leakage of the first or second heat transfer fluid through the openings. Each internal plate is thinner than an external plate. Thus, heat from inside the heat exchanger block can be dissipated through each opening 20 to the outside of the heat exchanger block. Each opening is located in a central portion of each external plate, excluding the edges of each external plate, and no opening is provided directly near the edges of the external plates. This helps to limit temperature differences within such a heat exchange device and the resulting stresses.

[0056] The heat exchange device further comprises four beam edges 80, each beam edge 80 being arranged to form an edge of the exchanger block. As can be seen on the figure 1 The beam edge 80 includes a recess 82, 83 on each main face visible from outside the heat exchange device, in the manner of the recesses 20 provided in the outer plate 14 of the exchanger block 12. Each recess 82, 83 facilitates the conduction of heat from the inside of the exchanger block to the outside of it via the areas of these recesses through the thickness of the walls of the beam edge 80.

[0057] The heat exchange device shown in figure 1 also includes: a first supply box 23 forming a solid peripheral wall between an orifice 24, forming an inlet for the first heat transfer fluid, and the first inlet 4 of the exchanger block 12, a second supply box 26 forming a solid peripheral wall between an orifice 26, forming an outlet for the first heat transfer fluid, and the first outlet 6 of the exchanger block 12, a third supply box 27 forming a solid peripheral wall between an orifice 28, forming an inlet for the second heat transfer fluid, and the second inlet 8 of the exchanger block 12, a fourth supply box 22 forming a solid peripheral wall between an orifice, forming an outlet for the second heat transfer fluid, and the second outlet 10 of the exchanger block 12.

[0058] Each orifice of each vent can also be connected to an inlet or outlet duct for the first heat transfer fluid or the second heat transfer fluid.

[0059] Protruding elements, forming added material components, can be incorporated into various surfaces of the heat exchanger components so as to be in contact with the first heat transfer fluid (preferably at its outlet, i.e., after it has been heated by the second heat transfer fluid) or the second heat transfer fluid (at the inlet and / or outlet of the circulation chamber of the heat exchanger block 12). Such protruding elements absorb heat from the heat transfer fluid they are in contact with and promote a temperature increase in the adjacent or peripheral elements of the heat exchanger block, which also helps to reduce the temperature gradients experienced by the heat exchanger block. Such protruding elements can, for example, be incorporated into the edges of the bundles and / or the inside of the feed boxes.

[0060] As can be seen on the figure 3, the surface of the beam edge 80 located in contact with the second heat transfer fluid (at the "hot" inlet 8) is provided with protruding elements 88 forming oblique ribs.

[0061] As can be seen on the figure 4 , the surface of the beam edge 80 located in contact with the first heat transfer fluid (at the "cold" outlet 6) is provided with protruding elements 89 (in the shape of an inverted V).

[0062] There figure 5 represents the feed box 27 of the heat exchange device, a portion of whose internal surface 30 is provided with pins 110, appearing here in the form of six rows of pins 110, each comprising between 20 and 25 pins from one edge to the other of the feed box 27.

[0063] There figure 6 represents the power supply box 22 of the heat exchange device, a portion of whose internal surface 32 is provided with three ribs 120 substantially parallel to each other.

[0064] The protruding elements 88, 89 in contact with the first heat transfer fluid (at its outlet 6) and the second heat transfer fluid (the "hot" fluid) store the heat from this fluid and thus promote and accelerate the increase in temperature of the adjacent or peripheral elements of the heat exchanger block.

[0065] THE figures 7 to 9 represent two other embodiments of beam edges 90, 100. Each beam edge represented at figures 7 to 9The system features protruding elements 92 and 102 configured to be in contact with either the first or second heat transfer fluid. This allows the protruding elements 92 and 102, in contact with the second heat transfer fluid (the "hot" fluid), to absorb the heat from this fluid, thereby promoting and accelerating the temperature increase of the adjacent or peripheral elements of the heat exchanger block. The protruding elements 92 and 102 thus recover heat by convection and transfer it by conduction to adjacent rooms where the temperature is lower than that of the protruding elements.

[0066] The protruding elements 92, 102 are arranged on end portions of each beam edge 90, 100, a flat area, devoid of such protruding elements, being provided between these two end portions.

[0067] In the embodiments represented in figures 7 to 9Each beam edge 90, 100 has a straight profile shape with a T-shaped cross-section (not symmetrical here). The projecting elements 92, 102 can be arranged on the same surface of each T-shaped beam edge 90, 100. In the embodiments shown in figures 7 to 9 , each edge of beam 90, 100 has a wall 94, 104, substantially orthogonal to the surface provided with the protruding elements 92, 102, free of which one face can be fixed to an edge of the exchanger block, the opposite face of the wall 94, 104, can be used to fix a supply and / or outlet box for the second heat transfer fluid.

[0068] The protruding elements can have various shapes, for example, fins, ribs, tongues, studs, spikes, teeth, or points.

[0069] In a first embodiment of a heat exchange device according to the invention shown in figures 7 and 8 The projecting elements are in the form of ribs 92. Three ribs 92 are provided here, for example, at each end of each beam edge 90 in the embodiment shown in figures 7 and 8 .

[0070] In a second embodiment of a heat exchange device according to the invention shown in the figure 9 The protruding elements are in the form of studs 102. Six studs 102 are provided here, for example, at each end of each beam edge 100 in the embodiment shown in the figure 9 .

[0071] In a third embodiment of a heat exchange device according to the invention (not shown), the protruding elements are in the form of portions of ducts or flow guides.

[0072] The protruding elements 92, 102 of a beam edge 90, 100 can be molded simultaneously with the beam edge during its manufacture, or else be welded or brazed onto its surface so as to form only one piece (in a different material or not).

[0073] Furthermore, in the illustrated embodiment, each internal layer of the heat exchanger block 12 is equipped with a flow guide 50 forming a plurality of substantially parallel channels. The spaces between the internal plates 13, 15, 18 are closed laterally by closing bars 60, 62. The internal plates 13, 15, 18 are arranged parallel to each other and parallel to the external plates 2.

[0074] In the variants represented at figures 1 to 9The path of the first and second heat transfer fluid flows within the heat exchanger block is essentially straight (not considering any curves that may occur in the presence of certain flow guides). It is, of course, also possible to use any other type of plate heat exchanger block, for example, in which the flow of one or both of the first and / or second heat transfer fluids follows a U-shaped or S-shaped path.

[0075] In the embodiments shown, flow guides 50 extend into the integrity of the internal layers of the exchanger block 12.

[0076] A heat exchange device according to the invention therefore effectively limits temperature gradients that could damage the exchanger block.

[0077] The invention is not limited to the embodiments described. In particular, nothing prevents the provision of protruding elements of different shapes on each beam edge.

Claims

1. Heat-exchange device comprising: - a flow enclosure defined by at least two external plates (14, 16), - a first inlet (4) for a first heat-transfer fluid into the flow enclosure, - a first outlet (6) for said first heat-transfer fluid out of the flow enclosure, - a second inlet (8) for a second heat-transfer fluid into the flow enclosure, - a second outlet (10) for said second heat-transfer fluid out of the flow enclosure, - an exchanger block (12) with plates disposed in the flow enclosure so as to be in fluid communication with the inlets (4, 8) and the outlets (6, 10) in order to permit the flow of the first heat-transfer fluid and of the second heat-transfer fluid into and through this exchanger block and the transfer of calories therebetween, - said exchanger block comprising a plurality of internal plates (13, 15, 18) disposed substantially parallel with respect to each other, characterized in that each external plate (14, 16) has at least one hollow (20) and in that at least one internal plate of said heat exchanger block is attached to each external plate so as to prevent any leakage of the first heat-transfer fluid and / or the second heat-transfer fluid through said hollow.

2. Device as claimed in claim 1, characterized in that it comprises at least one core band (80, 90, 100) arranged to form at least one edge of the exchanger block, each core band (80, 90, 100) having a plurality of protruding elements (88, 89, 92, 102) configured to be able to be in contact with at least one of said first heat-transfer fluid and second heat-transfer fluid.

3. Device as claimed in any one of claims 1 or 2, characterized in that the second heat-transfer fluid corresponds to the heat-transfer fluid which is at a temperature greater than the temperature of said first heat-transfer fluid.

4. Device as claimed in any one of claims 1 to 3, characterized in that it further comprises at least one box, referred to as supply box (22, 27), forming a solid peripheral wall between an orifice (28) and said flow enclosure, each supply box comprising an internal surface (30, 32) having a plurality of protruding elements (110, 112), said protruding elements being configured to be able to be in contact with said first heat-transfer fluid and / or said second heat-transfer fluid.

5. Device as claimed in any one of claims 2 or 4, characterized in that said protruding elements are at least partially in the form of ribs (92, 120).

6. Device as claimed in any one of claims 2 or 4, characterized in that said protruding elements are at least partially in the form of studs (102, 110).

7. Device as claimed in claim 2 and any one of claims 1 to 6, characterized in that said protruding elements (88, 92, 102) of a core band and said core band (80, 90, 100) are formed as one piece.

8. Device as claimed in any one of claims 1 to 7, characterized in that it comprises at least one core band (80) arranged to form at least one edge of the exchanger block, each core band (80) having at least one hollow (82, 83).

9. Device as claimed in any one of claims 1 to 8, characterized in that it comprises at least one flow guide (50) disposed between each internal plate (13, 15) of said exchanger block (12), each flow guide (50) being adapted to form a plurality of channels which are substantially parallel to each other.

10. Air-conditioning system characterized in that it comprises at least one heat-exchange device as claimed in any one of claims 1 to 9.

11. Vehicle - in particular an aircraft - characterized in that it comprises at least one air-conditioning system as claimed in claim 10.