Heat exchanger comprising at least one closure bar comprising at least one lug, air conditioning system and vehicle

Abstract

The invention relates to a heat exchanger comprising: - a heat exchanger block (2) arranged in a flow enclosure and comprising a plurality of plates (31) arranged substantially parallel to one another and bars (10) for closing each layer for the flow of the first fluid: - extending in a longitudinal direction between a first end portion (12) and a second end portion (13) extending substantially orthogonally to the longitudinal direction of the closure bar (10) and parallel to one another and forming part of a bundle edge of the heat exchanger, - comprising at least one lug (16) projecting substantially orthogonally to the longitudinal direction and parallel to the end portions (12, 13) of the closure bar (10), the lug (16) extending only over part of a width of the closure bar (10).

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: HEAT EXCHANGER INCLUDING AT LEAST ONE CLOSING BAR INCLUDING AT LEAST ONE LUG, AIR CONDITIONING SYSTEM AND VEHICLE Technical field of the invention

[0003] The invention relates to a heat exchanger, in particular a heat exchanger for an aircraft, comprising at least one locking bar including at least one lug.

[0004] The invention relates in particular to a plate heat exchanger 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 with the help of another fluid.

[0005] Technological background

[0006] Plate heat exchangers integrated into atmospheric vehicles can feature various fluid flow configurations, such as crossflow, U-shaped or Z-shaped, parallel flow, or counterflow. Many exchangers incorporate a U-shaped fluid circulation circuit. However, internal channels incorporating such a U-shaped configuration are complex and bulky to manufacture.

[0007] Document FR 2704310 describes a cross-circuit plate and bar heat exchanger in which a fluid follows a U-shaped path. According to an embodiment illustrated in Figure 5 of FR 2704310, it is in particular formed of two exchangers separated by a well and connected by a collector box.

[0008] Such a fluid reversing collector box is bulky and negatively impacts the size and mass of the exchanger.

[0009] The invention therefore aims to provide a heat exchanger that overcomes these drawbacks.

[0010] Objectives of the invention

[0011] The invention aims to provide a heat exchanger with improved compactness, simple manufacturing, and no significant additional cost. In particular, the invention aims to provide a heat exchanger with excellent structural resistance to mechanical stresses.

[0012] The invention also aims to provide a heat exchanger exhibiting excellent structural cohesion that is stable over time.

[0013] Description of the invention

[0014] To this end, the invention relates to a heat exchanger comprising: - a circulation chamber delimited by at least one first external plate and at least one second external plate and comprising a first inlet of a first fluid into the circulation chamber and a first outlet of said first fluid outside the circulation chamber,

[0015] - a second inlet of a second fluid into the circulation chamber and a second outlet of said second fluid out of the circulation chamber,

[0016] - a plate heat exchanger block positioned within the circulation chamber so as to be in fluid communication with the inlets and 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,

[0017] said heat exchanger block comprising a plurality of plates arranged substantially parallel to each other between said first outer plate and said second outer plate, said plates being arranged substantially parallel to said outer plates,

[0018] said heat exchanger block further comprising closure bars for each circulation layer of said first fluid

[0019] characterized in that at least one of said closure bars of each circulation layer of said first fluid:

[0020] extends in a longitudinal direction between two opposing longitudinal ends, a first longitudinal end having a first end portion and a second longitudinal end having a second end portion, each end portion extending substantially orthogonally to said longitudinal direction of said closure bar and parallel to each other, each end portion being configured to be able to form part of a beam border of said heat exchanger, includes at least one lug extending projecting from said closure bar, said lug extending only over a portion of a width of said closure bar so as to permit the passage of said second fluid.

[0021] A heat exchanger equipped with at least one such sealing bar not only increases the functional volume of the reversing zone of the second fluid but also reduces the volume, size, and mass of the exchanger. This configuration also strengthens the heat exchanger's structural integrity.

[0022] By beam edge we mean to designate a portion on which a frame or a box for the inlet and / or outlet of the fluid of the heat exchanger block can be fixed.

[0023] Such a heat exchanger can have different circulation configurations for the first and second fluids. Advantageously, according to the invention, the path of the first fluid flow within the exchanger block is substantially rectilinear. It is, of course, also possible to use any other type of plate exchanger block, for example, in which the flow of the first fluid follows a U-shaped or S-shaped path. The circulation of the second fluid can also follow various configurations, such as a Z-shaped configuration (for example, in the case where both the first and second fluids are in a liquid state). Advantageously, according to the invention, the principal direction of circulation of the second fluid is orthogonal to the principal direction of circulation of the first fluid.In particular, it may be a heat exchanger in which the second fluid follows a U-shaped path, with a reversing zone, or a multi-pass heat exchanger comprising at least two reversing zones for said second fluid. Advantageously, and according to the invention, said heat exchanger comprises at least one box delimiting a reversing zone for said second fluid, with said closing bars.

[0024] Advantageously, and according to the invention, said lug extends to a width less than 0.60 times the width of said locking bar. In particular, said lug extends to a width substantially equal to 0.5 times the width of said locking bar.

[0025] Advantageously and according to the invention, each lug extends substantially orthogonally to said longitudinal direction of said closure bar and parallel to said end portions of said closure bar.

[0026] In other words, advantageously and according to the invention, said locking bar has at least one main face from which said lug projects, said main face comprising at least one flat portion extending from said first longitudinal end to said second longitudinal end (without interruption, the lug not extending over the entire width of this main face). It is therefore in contact with this flat portion that said second fluid can also flow, without being obstructed by said lug.

[0027] Advantageously, according to the invention, at least one lug rests on a portion of a circulation plate or on an appendage of a circulation plate. It is also permissible to leave each lug free, without any of them being in contact with the surface of such a portion of the plate or such an appendage of a similar shape. These lugs nevertheless serve to reinforce the mechanical strength of the heat exchanger.

[0028] Advantageously, and according to the invention, each end portion of said at least one locking bar extends for a length substantially identical to the length of said lug. The length of each end portion and the length of said lug therefore correspond to a dimension extending substantially orthogonally to said longitudinal direction of said locking bar.

[0029] Advantageously, and according to one embodiment of the invention, each space between two adjacent plates defines a circulation layer for one of said first fluids and said second fluids, and said heat exchanger further comprises closure bars for each circulation layer of said second fluid. Advantageously, and according to one embodiment of the invention, said heat exchanger comprises a plurality of circulation plates for said second fluid, each circulation plate comprising a plurality of conduits configured to allow the circulation of said second fluid between said second inlet and said second outlet, and each space between two circulation plates defining a circulation layer for said first fluid. Advantageously, and according to the invention, each circulation plate for said second fluid is formed of a single piece incorporating said conduits.

[0030] The second fluid can be the fluid whose temperature is higher than that of the first fluid, or vice versa. Thus, advantageously and according to the invention, the second fluid is the fluid whose temperature is higher than that of the first fluid. In other words, the first fluid can be called the "cold" fluid and the second fluid can be called the "hot" fluid.

[0031] 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.

[0032] Each circulation layer of the first and second fluids can be equipped with any type of flow guide (or fins). Advantageously, according to the invention, each circulation layer comprises at least one flow guide having a corrugated shape. Such a flow guide can take various forms and be, for example, a corrugated sheet, a corrugated strip, or zigzag fins.

[0033] Each flow guide can be attached to the plates, for example, by brazing or welding. Each flow guide can be attached to the external 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 an internal plate.

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

[0035] 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.

[0036] Advantageously, according to the invention, the second inlet has an inlet port for the second fluid into the circulation chamber. Advantageously, according to the invention, the second 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 supply or discharge line for the first fluid.

[0037] 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.

[0038] The invention extends to an air conditioning system comprising at least one heat exchanger according to the invention.

[0039] The invention extends to a vehicle, in particular an aircraft, comprising at least one air conditioning system according to the invention.

[0040] 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.

[0041] List of figures

[0042] 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:

[0043] [Fig. 1] is a schematic perspective view of a heat exchanger according to the invention.

[0044] [Fig. 2] is a schematic perspective view of part of a heat exchanger block according to a first embodiment of the invention. [Fig. 3] is a schematic perspective view of part of a heat exchanger block according to a second embodiment of the invention.

[0045] [Fig. 4] is a schematic perspective view of part of a heat exchanger block according to a third embodiment of the invention.

[0046] [Fig. 5] is a schematic perspective view of part of a heat exchanger block of a heat exchanger according to the third embodiment of the invention.

[0047] [Fig. 6] is a schematic perspective view of a closing bar of a heat exchanger according to the invention.

[0048] Detailed description of an embodiment of the invention. In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0049] In addition, identical, similar or analogous elements are designated by the same references in all figures.

[0050] Figure 1 schematically illustrates a heat exchanger according to the invention. Figures 2 to 5 schematically illustrate a plate heat exchanger block according to three distinct embodiments, each of which can be used in a heat exchanger such as that illustrated in Figure 1. Figure 6 schematically illustrates a closing bar 10 used in each of the embodiments illustrated in Figures 2 to 5.

[0051] A heat exchanger 1 as illustrated in Figure 1 comprises a circulation chamber delimited by a first external plate 40 and a second external plate 42 and comprises a first inlet 8 of a first fluid into the circulation chamber and a first outlet 6 of the first fluid out of the circulation chamber.

[0052] The heat exchanger 1 also includes a second inlet 60 of a second fluid into the circulation chamber and a second outlet 62 of the second fluid out of the circulation chamber.

[0053] The heat exchanger 1 also includes a plate heat exchanger block arranged in the circulation enclosure so as to be in fluid communication with the inlets 8, 60 and the outlets 6, 62 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.

[0054] The exchanger block comprises a plurality of plates 31, 35, 37 arranged substantially parallel to each other between the first outer plate 40 and the second outer plate 42, the plates 31, 35, 37 being arranged substantially parallel to the outer plates 40, 42.

[0055] The heat exchanger block further includes closure bars 10 for each circulation layer of the first fluid. Each closure bar 10, as illustrated in particular in Figure 6, extends in a longitudinal direction between a first longitudinal end having a first end portion 12 and a second longitudinal end having a second end portion 13. Each end portion 12, 13 extends substantially orthogonally to the longitudinal direction of the closure bar 10 and parallel to each other, and is configured to form part of a beam edge of the heat exchanger 1.

[0056] Furthermore, each closing bar 10 includes a lug 16 projecting substantially orthogonally to its longitudinal direction and parallel to the end portions 12, 13. The lug 16 extends only over a portion 20 wide of the closing bar 10 so as to allow the passage of the second fluid within a reversing zone of the heat exchanger. Each end portion 12, 13 of a closing bar 10 extends for a length 14 substantially equal to the length of each lug 16.

[0057] In each of the embodiments shown in Figures 2 to 6, each lug 16 extends over a width 21 substantially equal to half the width 20 of the closing bar 10. Such a configuration of each lug 16 thus allows the passage of the second fluid around it and, in particular, immediately above it, over a width 22 left free between the lug 16 and the adjacent plate or the next lug. The width 20 of the closing bar 10 could also have been designated "height" since it is the dimension extending in the vertical direction in the diagram of Figure 6. The edge on which the closing bar 10 rests in Figure 6 can be designated "thickness" of the closing bar 10.Figure 1 shows that the heat exchanger 1 includes a second fluid inlet box 50 comprising a second fluid inlet port, two second fluid change direction boxes 54, 56 (corresponding to the base of the U of the U-shaped circuit) and a second fluid outlet box 52 comprising a second fluid outlet port.

[0058] According to the first embodiment of a heat exchanger block 2 illustrated in Figure 2, each space between two adjacent plates 31 defines a circulation layer for one of the first fluid and one of the second fluid. The heat exchanger block 2 includes closing bars 4 for each circulation layer of the second fluid. The plate heat exchanger block 2 illustrated in Figure 2 comprises a stack of flat plates 31 arranged parallel to each other between the first outer plate 40 and the second outer plate 42. Each circulation layer of the second fluid includes a flow guide formed by a plurality of successive sections, each having a crenellated profile, so as to form guide walls and surface contact areas with the plates 31 and providing conduits 32 (or channels) for the circulation of the second fluid. Each lug 16 of a closing bar 10 rests on a distal portion of a bar 34 separating two directions of circulation of the second fluid.

[0059] According to the second and third embodiments of an exchanger block 5 and 7 illustrated respectively in figures 3 to 5, each exchanger block 5, 7 comprises a plurality of second fluid circulation plates 35, 37, each formed of a single piece incorporating the conduits 36, 38. Each space between two circulation plates 35, 37 defines a circulation layer of said first fluid.

[0060] In the second embodiment illustrated in Figure 3, the plate heat exchanger block 5 comprises a plurality of circulation plates 35 for the second fluid extending to the ends of each lug 16 and of each end portion 12, 13 of the closing bars 10. Each lug 16 rests on a central portion of a circulation plate 35 (or on the outer plate 42 for the lug 16 of the last closing bar 10 (the lowest one in the drawings)).

[0061] In the third embodiment, illustrated in figures 4 and 5, the circulation plates 37 of the second fluid of the exchanger block 7 are partially cut out so as to form a recess following the shape of the closing bars 10. The lug 16 of each closing bar 10 rests on an appendage 39 of a circulation plate 37 (or on the external plate 42 for the lug 16 of the last closing bar 10 (the lowest one in the drawings)).

[0062] The first fluid, called the "cold" fluid, can for example flow along a main flow direction of the first fluid between a first inlet 8 and a first outlet 6. The second fluid, called the "hot" fluid, can flow along a main flow direction of the second fluid between a second inlet 60 through the inlet and a second outlet 62 through the outlet (figure 1).

[0063] In the three embodiments of the heat exchanger illustrated in Figures 1 to 5, each circulation layer of the first fluid comprises a flow guide 30 formed by a plurality of successive sections, each with a serrated profile, so as to form guide walls and surface contact areas with the plates. It is also permissible to use so-called "offset" flow guides, consisting of two successive sections offset laterally by a distance called half-step, such that the guide walls of a section directly adjacent to another section are offset laterally. Any other type of flow guide can also be used within each circulation layer of the first fluid (or the second fluid, particularly for the embodiment illustrated in Figure 2) of the heat exchanger.

[0064] The inventors evaluated the efficiency of a heat exchanger incorporating such closure bars 10 and demonstrated the advantages of configuring these second fluid changeover (or reversal) zones in terms of mass and volume savings for the heat exchanger, while also improving its mechanical strength. Indeed, as can be seen in Figures 2 to 5, such closure bars 10 with lugs 16 prevent the formation of a continuous "wall" that would impede fluid flow at the junction of the two second fluid circulation zones at the reversal zone, thereby reducing the volume of the fluid reversal boxes.

[0065] The invention is not limited to the embodiments described. In particular, nothing prevents the provision of a multi-pass heat exchanger comprising, for example, three (or more) reversing zones for said second fluid.

Claims

DEMANDS 1. Heat exchanger (1) comprising: - a circulation enclosure delimited by at least one first external plate (40) and at least one second external plate (42) and comprising a first inlet (8) of a first fluid into the circulation enclosure and a first outlet (6) of said first fluid out of the circulation enclosure, - a second inlet (60) of a second fluid into the circulation chamber and a second outlet (62) of said second fluid out of the circulation chamber, - a plate heat exchanger block (2, 5, 7) arranged in the circulation enclosure so as to be in fluid communication with the inlets (8, 60) and outlets (6, 62) 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, said heat exchanger block comprising a plurality of plates (31, 35, 37) arranged substantially parallel to each other between said first outer plate (40) and said second outer plate (42), said plates (31, 35, 37) being arranged substantially parallel to said outer plates (40, 42), said heat exchanger block further comprising closure bars (10) for each circulation layer of said first fluid, characterized in that at least one of said closure bars (10) of each circulation layer of said first fluid: - extends along a longitudinal direction between two longitudinal ends opposite each other, a first longitudinal end having a first end portion (12) and a second longitudinal end having a second end portion (13), each end portion (12, 13) extending substantially orthogonally to said longitudinal direction of said closure bar (10) and parallel to each other, each end portion (12, 13) being configured to be able to form part of a beam border of said heat exchanger (1), - includes at least one lug (16) extending in projection, said lug (16) extending only over a portion of a width (20) of said closure bar (10) so as to permit the passage of said second fluid.

2. Heat exchanger according to claim 1, characterized in that each lug (16) extends substantially orthogonally to said longitudinal direction of said closure bar and parallel to said end portions of said closure bar.

3. Heat exchanger according to any one of claims 1 or 2, characterized in that each space between two adjacent plates (31) defines a circulation layer of one of said first fluid and of said second fluid, and in that said heat exchanger further comprises closure bars (4) of each circulation layer of said second fluid.

4. Heat exchanger according to any one of claims 1 or 2, characterized in that it comprises a plurality of circulation plates (35, 37) of said second fluid, each circulation plate (35, 37) comprising a plurality of conduits (36, 38) configured to permit the circulation of said second fluid between said second inlet (60) and said second outlet (62) and each space between two circulation plates (35, 37) defining a circulation layer of said first fluid.

5. Heat exchanger according to claim 4, characterized in that each circulation plate (35, 37) of said second fluid is formed of a single piece incorporating said conduits (36, 38).

6. Heat exchanger according to any one of claims 1 to 5, characterized in that it comprises at least one box (54, 56) delimiting, with said closing bars (10), a turning zone of said second fluid.

7. Heat exchanger according to any one of claims 4 or 5, characterized in that at least one lug (16) rests on a portion of a circulation plate (35) or on an appendage (39) of a circulation plate (37).

8. Heat exchanger according to any one of claims 1 to 7, characterized in that each end portion (12, 13) of said at least one closing bar (10) extends over a length (14) substantially identical to the length of said lug (16).

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

10. Vehicle - in particular aircraft - characterized in that it comprises at least one air conditioning system according to claim 9.

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