HEAT EXCHANGER WITH AT LEAST ONE SIDE COVER PLATE, AIR CONDITIONING AND VEHICLE

Description

Technical field of the invention

[0001] The invention relates to a heat exchanger. In particular, the invention relates to a plate and fin heat exchanger that can be used in an air conditioning system, for example in an aircraft, railway or land vehicle.

[0002] The invention relates in particular to a plate heat exchanger, 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. Technological background

[0003] Heat exchangers are used to enable heat transfer between at least two fluids, particularly to cool or heat one fluid using another. Heat exchangers are used in many applications, notably in air conditioning systems for aircraft, railways, and roads, where they help regulate the temperature of the conditioned air at various stages of the process.

[0004] Most heat exchangers currently used on aircraft consist of a generally rectangular heat exchange chamber housing a stack of plates and fins (also referred to as a "plate or fin bundle") that form stacked circulation channels, alternately for the hot and cold passes. Thus, the hot pass supplying one side of the exchanger flows through the channels of the different layers, and the cold pass supplying another side of the exchanger flows through the channels sandwiched between two channels of the hot pass.

[0005] This architecture allows each hot channel to be inserted between two cold channels along the entire length or height of the exchanger, thus ensuring heat exchange between the two fluids.

[0006] Various circulation configurations for the two fluids within this stack of plates and fins are possible. Cross-flow heat exchangers are configured so that the hot and cold circuits are transverse to each other. There are also exchangers with more complex circulation configurations. Among these are heat exchangers where the hot and cold circuits flow in opposite directions, meaning that the hot and cold air flows parallel to each other.

[0007] In these heat exchangers, certain faces or portions, through which no inlet or outlet is provided for the hot or cold pass, are formed by a series of closing bars corresponding to the hot and cold passes. US 3 613 782, for example, proposes a counterflow heat exchanger with a Z or U configuration comprising such portions equipped with closing bars.

[0008] Such a wall of hot and cold sealing bars (or strips) results in significant local rigidity. Under the mechanical and / or thermal stresses to which heat exchangers are subjected, particularly when integrated into naturally aspirated vehicles, such local rigidity increases the risk of fluid leakage.

[0009] Furthermore, IT UB20 160 428 describes a plate heat exchanger, each plate being provided with means for interlocking and retaining between overlapping sheets, these means comprising, on at least part of two opposite edges of the sheet, flaps formed by folding or by the application of added elements. It includes additional linear connection profiles forming flanges for connecting the conduits carrying the fluids to the inlet sections and to the outlet sections of the primary and secondary fluids.

[0010] US 2021 / 199392 describes a plate and fin heat exchanger in which closure bars are always provided on the third and fourth faces.

[0011] US 5,823,247 describes a plate heat exchanger comprising a stack of parallel plates between a first and second supporting plate, in which openings are provided. The plates form the walls of the fluid inlet and outlet chambers.

[0012] The invention therefore aims to provide a heat exchanger that overcomes these drawbacks. Objectives of the invention

[0013] The invention aims to provide a heat exchanger with a very low risk of fluid leakage.

[0014] The invention aims in particular to provide a heat exchanger exhibiting excellent structural cohesion that is stable over time.

[0015] The invention also aims to provide a heat exchanger with excellent efficiency. Description of the invention

[0016] To this end, the invention relates to a plate heat exchanger, configured for heat exchange between a first fluid circulating in a first pass and a second fluid circulating in a second pass, the fluids circulating between two external plates, comprising a plate exchanger block comprising a plurality of internal plates arranged substantially parallel to each other, said internal plates being arranged substantially parallel to the external plates, characterized in that it comprises at least one lateral encapsulation plate extending substantially orthogonally to said internal plates, each lateral encapsulation plate being fixed in contact with said external plates, so as to laterally close said second pass.

[0017] A heat exchanger according to the invention thus makes it possible to replace, at least partially, the sealing bars that close one of the fluid passes of the heat exchanger. This reduces the local rigidity associated with the presence of a series of sealing bars in a heat exchanger. It also helps to homogenize the structure of the bundle.

[0018] Advantageously, according to the invention, each lateral encapsulation plate is fixed, for example welded, to the outer plates at their lateral ends, which allows each plate to be detached from the bundle. Each lateral encapsulation plate is therefore not fixed (nor welded) to said inner plates.

[0019] A heat exchanger according to the invention therefore includes a passage, called the first fluid pass, allowing the circulation of a flow of the first fluid between a first inlet and a first outlet of said exchanger block.

[0020] A heat exchanger according to the invention includes a passage, called the second fluid pass, allowing the circulation of a flow of the second fluid between a second inlet and a second outlet of said exchanger block.

[0021] Advantageously and according to the invention, each lateral encapsulation plate has a main flat portion of rectangular shape.

[0022] Advantageously and according to the invention, each lateral encapsulation plate has at least one first longitudinal shoulder adapted to be able to form a border for an inlet and / or outlet of said second fluid.

[0023] Advantageously and according to the invention each lateral encapsulation plate has at least one second longitudinal shoulder adapted to be able to extend into contact with an edge for an inlet and / or outlet of said first fluid.

[0024] Advantageously and according to the invention, each lateral encapsulation plate extends opposite a face of said plate exchanger block devoid of closing bars of said second pass, said face being provided with closing bars of said first pass.

[0025] Each encapsulating side plate can be positioned in contact with the internal plates or not. Advantageously, according to the invention, each encapsulating side plate is configured so as not to be in contact with the internal plates. Alternatively, according to another embodiment of a plate heat exchanger according to the invention, each encapsulating side plate is configured to be in contact with the internal plates. This latter embodiment is particularly advantageous in terms of mechanical strength, especially with respect to mechanical stresses or certain mechanical strains.

[0026] A heat exchanger according to the invention can have different circulation configurations for the first and second fluids within the exchanger block. It is possible to use an exchanger block in which the flow of one or both of the first or second heat transfer fluids follows a U-shaped, S-shaped, or Z-shaped path. Advantageously, and according to the invention, the heat exchanger is configured for counter-current heat exchange between the first fluid circulating in the first pass and the second fluid circulating in the second pass. It is also possible to provide a heat exchanger with a portion in which the heat exchange is of the co-current type, that is, the flows of the first and second fluids follow parallel directions.

[0027] Advantageously, according to the invention, the first fluid flows between the internal plates along a principal direction of flow of the first fluid. Advantageously, according to the invention, the second fluid flows between the internal plates along a principal direction of flow of the second fluid. Advantageously, according to the invention, each lateral encapsulation plate is configured to extend along a plane parallel to the principal direction of flow of the first fluid and / or to the principal direction of flow of the second fluid.

[0028] Advantageously and according to the invention, said heat exchanger according to the invention comprises two lateral encapsulation plates.

[0029] The second heat transfer fluid corresponds, for example, to the heat transfer fluid whose temperature is lower than the temperature of the first fluid, or vice versa. In other words, the first fluid can be called the "hot" fluid and the second fluid can be called the "cold" fluid.

[0030] 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.

[0031] Flow guides can be inserted between the inner plates of the heat exchanger block. Each flow guide can have a corrugated shape, with the height of the corrugations being approximately equal to the distance between the inner plates. Thus, each flow guide has multiple external and internal zones in surface contact with the inner face of the inner plates. Each flow guide can have multiple corrugations to form multiple circulation channels for the first and second fluids within the heat exchanger block. Each flow guide can have a corrugated profile with a regular, periodic shape, for example, sinusoidal or crenellated.

[0032] Each flow guide can be secured to the internal plates by a plurality of surface contacts. In particular, each flow guide can be secured to the internal plates, for example, by brazing or welding.

[0033] The heat exchanger according to the invention can be formed from at least one material selected from metallic materials, composite materials, polymer materials, ceramic materials, in particular graphite, glass... In particular, in a particularly advantageous embodiment of a heat exchanger according to the invention, the plates are formed from metallic material, in particular from at least one material selected from the group consisting of steels, copper, aluminum, metallic alloys (in particular superalloys) and mixtures thereof.

[0034] The invention extends to an air conditioning system comprising at least one heat exchanger according to the invention. This may, in particular, be a non-contact counter-flow heat exchanger or a U- or Z-flow heat exchanger.

[0035] The invention extends to a vehicle, in particular an aircraft, comprising at least one air conditioning system according to the invention.

[0036] The invention also relates to a heat exchanger, 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

[0037] 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 partial schematic perspective view of a heat exchanger according to the invention, [ Fig. 2 ] is a partial schematic perspective view of a heat exchanger according to the invention, [ Fig. 3 ] is a schematic cross-sectional view of a heat exchanger according to the invention. Detailed description of an embodiment of the invention

[0038] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0039] In addition, identical, similar or analogous elements are designated by the same references in all figures.

[0040] There figure 1 This schematically illustrates a plate heat exchanger 1, configured for heat exchange between a first fluid circulating in a first pass and a second fluid circulating in a second pass. The heat exchanger 1 comprises two external plates 2 between which the plates are arranged.

[0041] The plate heat exchanger block comprises a stack of flat internal plates, between which flow guides in the form of corrugated sheets are inserted. A first and a second fluid circulate in the spaces between the internal plates.

[0042] The internal plates are arranged parallel to each other. The first fluid flows between a first inlet 3 and a first outlet 4. The second fluid flows between a second inlet 5 and a second outlet 6.

[0043] The heat exchanger 1 comprises two lateral encapsulation plates 20, each extending substantially orthogonally to the inner plates 12, 14. Each lateral encapsulation plate 20 is fixed in contact with the outer plates 2 so as to close the second pass.

[0044] Each lateral encapsulation plate 20 is welded between the external plates 2 on the edges of the exchanger beam (commonly called "core-band" in English), which allows each plate to be decoupled from the beam unlike the closure bars used in a heat exchanger according to the prior art, each lateral encapsulation plate 20 not being fixed (and therefore not welded in particular) to the internal plates.

[0045] The first fluid is, for example, the so-called "hot" fluid and circulates in the hot pass (first pass) while the second fluid is the so-called "cold" fluid circulating in the cold pass (second pass).

[0046] As can be seen on the figure 2 , each lateral encapsulation plate 20 has a main flat rectangular portion and two shoulders 22, 23 along opposite edges of the main portion: A first longitudinal shoulder 22 forms a border for an inlet and / or outlet of said second fluid. A second longitudinal shoulder 23 is adapted to be able to extend into contact with a beam border 40 for an inlet or outlet of the first fluid.

[0047] The first shoulder 22 of the lateral encapsulation plate 20 forms a beam border at the cold pass inlet on which a cold fluid inlet frame or box can be fixed.

[0048] Each lateral encapsulation plate 20 extends opposite a face of the plate heat exchanger block that lacks second-pass closing bars but is equipped only with first-pass closing bars 60. As can be seen on the figure 1The second pass, in these portions, has layers 50 without sealing bars. In the illustrated embodiment, the lateral encapsulation plates thus eliminate the need for the so-called "cold" sealing bars on the faces or portions of the heat exchanger block through which there is no inlet or outlet for the hot or cold pass. The invention therefore eliminates the walls of sealing bars (or strips) formed by a succession of sealing bars corresponding to the hot and cold passes.

[0049] In the final position, after being fixed, for example by welding, to the external plates 2, the lateral encapsulation plates 20 do not need to be in contact with the ends of the internal plates.

[0050] The heat exchanger shown in figures 1 to 3 is of the contrarian type. As can be seen on the figure 3(longitudinal section of the exchanger along a plane parallel to the internal plates), a counter-current portion extends between the two encapsulation plates 20, the first and second fluids each following a Z-shaped path. Any other type of fluid path configuration is of course also possible, a U-shaped circuit for example.

[0051] In the illustrated embodiment, the plate exchanger block has a general shape of a right prism with a hexagonal base and therefore has eight main faces, two of these faces being formed by the two external plates 2 and two other of these faces being formed by the two lateral encapsulation plates 20.

[0052] In the illustrated embodiment, the first inlet 3 has an inlet port for the first fluid formed in an inlet box 30. Similarly, the first outlet 4 has an outlet port formed in an outlet box 31 for the first fluid from the heat exchanger block. Each port has a single orifice forming either an inlet or outlet, an opening to the plate heat exchanger block, and a solid peripheral wall between this orifice and the opening. Each orifice of each port can be connected to a supply or discharge line for the first fluid.

[0053] In the illustrated embodiment, the boxes 30, 31 are welded onto the so-called "hot" beam edges 40 of the exchanger.

[0054] In the illustrated embodiment, an input frame 34 is fixed at the level of the second input 5 and an output frame 35 is fixed at the level of the second output 6.

[0055] A heat exchanger according to the invention effectively eliminates the risk of leakage in a heat exchanger block. A heat exchanger according to the invention eliminates the need to weld one of the two edges of the bundle, thus freeing up two of the six corners of the bundle.

[0056] The invention is not limited to the embodiments described above. In particular, the encapsulation side plates, closure bars, beam edges, and manifolds can have different shapes. The hot air circulation circuits can, as already described, have different shapes from those shown.

Claims

1. Plate heat exchanger (1), configured for a heat exchange between a first fluid flowing in a first pass and a second fluid flowing in a second pass, the fluids flowing between two external plates (2), comprising: a plate exchanger block comprising a plurality of internal plates (12, 14) arranged substantially in parallel with each other, said internal plates being arranged substantially in parallel with the external plates (2), said first fluid and said second fluid flowing in spaces between said internal plates, characterized in that it comprises at least one lateral encapsulation plate (20) extending substantially orthogonally to said internal plates, each lateral encapsulation plate being fixed in contact with said external plates (2) so as to laterally close said second pass, each lateral encapsulation plate (20) extending facing a face of said plate exchanger block having no bars closing said second pass, said face being provided with bars (60) closing said first pass.

2. Exchanger as claimed in claim 1, characterized in that each lateral encapsulation plate (20) has a main, rectangular, planar portion.

3. Exchanger as claimed in any one of claims 1 or 2, characterized in that each lateral encapsulation plate (20) has at least one first longitudinal shoulder (22) shaped to be able to form a band for an inlet (5) for said second fluid and / or an outlet (6) for said second fluid.

4. Exchanger as claimed in any one of claims 1 to 3, characterized in that each lateral encapsulation plate (20) has at least one second longitudinal shoulder (23) shaped to be able to extend in contact with a band (40) for an inlet (3) and / or an outlet (4) for said first fluid.

5. Exchanger as claimed in any one of claims 1 to 4, characterized in that each lateral encapsulation plate (20) is configured so as not to be in contact with the internal plates.

6. Exchanger as claimed in any one of claims 1 to 5, characterized in that it is configured for a counterflow heat exchange between said first fluid flowing in the first pass and said second fluid flowing in the second pass.

7. Exchanger as claimed in any one of claims 1 to 6, characterized in that it comprises two lateral encapsulation plates (20).

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

9. Vehicle - in particular an aircraft - characterized in that it comprises at least one air-conditioning system as claimed in claim 8.