Plate heat exchanger with mixing device

Abstract

Plate heat exchanger comprising a mixing device The present invention relates to a heat exchanger (100) comprising a bundle of plates (50) forming a plurality of circulation channels (51) for a refrigerant fluid (FR), and a refrigerant fluid inlet manifold (48) serving the circulation channels (51), the inlet manifold (48, 11) comprising openings (541, 561) in the plates (52, 54, 56) of the bundle of plates (50), the openings delimiting at least in part a cylindrical zone (480) transverse to the bundle of plates (50), the heat exchanger (100) being characterized in that it comprises at least one mixing device (546, 566) for the refrigerant fluid (FR) extending in the inlet manifold (48) and made of a material with at least one of the plates (54, 56) of the bundle of plates (50). (Figure 1)

Description

Title of the invention: Plate heat exchanger comprising a mixing device

[0001] The present invention relates to the field of thermodynamics and more specifically concerns a heat exchanger intended in particular to be used for cooling components of a vehicle.

[0002] In an electric or hybrid vehicle, it is common to cool the electric battery, the electric motor and the power electronics of the vehicle by a heat transfer fluid such as water, circulating in a heat transfer fluid circuit running through these components to be cooled, the heat transfer fluid itself being cooled by a heat exchanger receiving on the one hand the heat transfer fluid, and on the other hand a refrigerant fluid. The refrigerant fluid undergoes a thermodynamic cycle in a separate refrigerant circuit using for example a compressor, a condenser, an internal heat exchanger and an expansion member.

[0003] When rapidly charging the electric battery of an electric or hybrid vehicle, the electric current being high, the thermal power to be dissipated to cool the electric battery is significant, for example of the order of 10,000 Watts. Similarly, when the electric or hybrid vehicle is traveling at high speed, the thermal power to be dissipated in the electric motor, the power electronics and the electric battery is significant and therefore requires a heat exchanger sized accordingly, known as "high performance".

[0004] The heat exchanger being formed from a bundle of stacked and brazed plates delimiting channels for circulation of the refrigerant fluid or the heat transfer liquid, the number of plates of the heat exchanger of the electric or hybrid vehicle is all the more important as it must dissipate a high thermal power.

[0005] However, during less energy-intensive use of the electric or hybrid vehicle, for example during slow charging of the electric battery of the electric vehicle, or when driving at low speed of the electric vehicle, the thermal power of the electric battery to be dissipated is lower, for example of the order of 4000 Watts. However, the efficiency of a “high performance” heat exchanger is not optimal at medium or low load, because the number of plates and the dimensioning of the channels of such a heat exchanger have been optimized for use at high load. At medium or low load, the distribution of the liquid and gas phases of the refrigerant in the heat exchanger is therefore not homogeneous and is not very efficient.

[0006] There is therefore a need for a high-performance heat exchanger, in particular for an electric or hybrid vehicle, with improved thermal power and efficiency, particularly at low and medium loads, allowing the cooling of vehicle components. The vehicle components to be cooled preferably include the electric battery, the electric motor, the power electronics, but also the vehicle interior.

[0007] The present invention at least partially overcomes the drawbacks of the prior art by providing a plate bundle heat exchanger, in which the distribution of a refrigerant fluid in the plate bundle is improved.

[0008] To this end, the present invention provides a heat exchanger comprising a bundle of plates forming a plurality of channels for circulating a refrigerant fluid, and a refrigerant fluid inlet manifold serving the circulation channels, the inlet manifold comprising openings in the plates of the bundle of plates, the openings delimiting at least in part a cylindrical zone in the inlet manifold, the heat exchanger comprising at least one device for mixing the refrigerant fluid extending into the inlet manifold and made of a single material with at least one of the plates of the bundle of plates.

[0009] Thanks to the invention, the refrigerant fluid which before entering the heat exchanger is in the form of a separate two-phase flow, flows into the inlet manifold in the form of a dispersed two-phase flow due to the mixing device. Indeed, the refrigerant fluid is formed of a gaseous phase, a liquid phase and a small percentage of oil. Before entering the heat exchanger, it flows in pockets or plugs. The pockets or plugs of the refrigerant fluid are sprayed by contact with the mixing device, which forms singularities in the inlet manifold and by a depression phenomenon after each passage of the refrigerant fluid through an opening in a plate of the plate bundle, which makes it possible to efficiently mix the liquid phase and the gaseous phase of the refrigerant fluid.

[0010] Furthermore, since the mixing device is made of a single material with at least one of the plates of the plate bundle, the heat exchanger according to the invention is economical in terms of resources used and allows rapid manufacturing, since the assembly of the mixing device is the same as the assembly of the heat exchanger by brazing the plate bundle.

[0011] According to an advantageous characteristic of the heat exchanger according to the invention, the mixing device comprises at least one diversion means leading the refrigerant fluid towards an upper part of the inlet manifold.

[0012] This upper part of the inlet manifold is located opposite a part of the heat exchanger comprising bends of the circulation channels of the heat exchanger, when these circulation channels are U-shaped, or is located opposite outlets of the circulation channels when these have a circulation in one or three passes. In other words, this upper part of the inlet manifold which receives little refrigerant in the prior art, receives more thanks to the mixing device. In particular when the latter takes the form of a spiral, this deflects radially over the entire angular extent of the inlet manifold, a peripheral portion of the flow of refrigerant arriving in the inlet manifold. As a result, the refrigerant manages to flow more easily in an external peripheral portion of the circulation channels, proximal to the side walls of the heat exchanger formed by the edges of the plate bundle. Thus the flow of refrigerant is better distributed inside each circulation channel, which improves the heat transfer coefficient of the heat exchanger and reduces pressure variations in each circulation channel.

[0013] Preferably, the mixing device is part of the edge of an opening of the plate, the mixing device projecting into the cylindrical zone, extending radially towards a central axis of the cylindrical zone. By this embodiment the mixing device comes into contact with the flow of refrigerant fluid in the inlet manifold to create the singularities making it possible to obtain a dispersed two-phase flow. Furthermore, in this embodiment, the mixing device is for example obtained by stamping and / or semi-cutting the edge of the opening. In this way the mixing device is easily produced without additional material waste compared to the prior art.

[0014] Preferably in this embodiment of the invention, the mixing device comprises a foot extending over an angular portion of the opening while being connected to the plate, the mixing device also comprising a head extending the foot by extending at a distance from a portion of the edge of the opening located angularly at the same level as the head. The head is therefore cantilevered relative to the rest of the opening, while being located opposite an intake mouth of the inlet manifold. This cantilevered head makes it possible to divert a portion of the flow of refrigerant fluid radially towards the circulation channels, in particular towards the upper part of the inlet manifold.

[0015] For example, the mixing device extends over the entire edge of the opening and forms a helical coil whose axis coincides with the central axis of the cylindrical zone, a first angular portion of the helical coil forming the foot and a second angular portion of the helical coil forming the head. This characteristic gives a rotational effect to the flow deflected by the mixing device, which facilitates the projection of refrigerant fluid at the outlet of the inlet manifold towards the circulation channels.

[0016] According to an advantageous characteristic of the heat exchanger according to the invention, the mixing device comprises at least a first mixing device formed on an edge of an opening of a first plate adjacent to a second plate, and a second mixing device formed on an edge of an opening of the second plate, the first and second mixing devices projecting between the first plate and the second plate. This arrangement angularly enlarges the projection area of ​​refrigerant fluid at the outlet of the inlet manifold towards the circulation channels, by increasing the number of deflection means between two adjacent plates of the plate bundle.

[0017] In one embodiment of the invention, the first and second mixing devices join and together form a helix portion whose axis coincides with the central axis of the cylindrical zone. In particular, the turn of the first plate comprises an angular end surface arranged orthogonally to the main extension plane of the cheek, at the same position as an angular end surface of the turn of the second plate. Thus, these surfaces are arranged against each other and are brazed together during the brazing of the heat exchanger, to form the helix portion. This arrangement of the mixing devices makes it possible to homogenize the distribution of refrigerant fluid in the plate bundle by limiting pressure losses.

[0018] Preferably in this embodiment, the plate bundle comprises an alternation of plates identical to the first plate and plates identical to the second plate, the first and second mixing devices of the plates of this alternation forming a helix extending over the length of the refrigerant inlet manifold opposite the circulation channels. Thus the refrigerant is distributed homogeneously throughout the plate bundle.

[0019] According to an advantageous characteristic of the heat exchanger according to the invention, the inlet manifold comprises a cylindrical passage transverse to the circulation channels, delimited at least in part by the mixing device. This cylindrical passage makes it possible to bring the refrigerant fluid to the distribution channels furthest from the inlet mouth of the inlet manifold. Preferably, a diameter of the cylindrical passage is between 4 and 8 millimeters, the plate bundle comprising between 30 and 70 plates. This diameter, smaller than in the prior art, accelerates the refrigerant fluid and allows it to form a jet improving the distribution of the refrigerant fluid throughout the inlet manifold formed by a large number of plates. Thus, the invention provides an improvement in the distribution of refrigerant fluid at low, medium or high load.

[0020] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0021] [Fig-1] is a perspective view of a section of a heat exchanger according to the invention, making visible an inlet manifold of this heat exchanger, in a first embodiment of the invention,

[0022] [Fig.2] is an enlargement of a portion of the inlet manifold of [Fig. 1], in which extend mixing devices,

[0023] [Fig.3] is a perspective view of two different plates of a beam of heat exchanger plates of [Fig.l],

[0024] [Fig.4] is an enlargement of a portion of one of the plates of [Fig.3], comprising a mixing device,

[0025] [Fig.5] is an enlargement of a portion of the other of the plates of [Fig.3], comprising a mixing device,

[0026] [Fig.6] is a perspective view of a section of a heat exchanger according to the invention, making visible an inlet manifold of this heat exchanger, in a second embodiment of the invention,

[0027] [Fig.7] schematically represents a distribution of refrigerant fluid on a plate of a plate bundle without a mixing device, and

[0028] [Fig.8] schematically represents a distribution of refrigerant fluid on a heat exchanger plate of [Fig.6], comprising mixing devices.

[0029] According to a first embodiment of the invention shown [Fig.l], a heat exchanger 100 according to the invention comprises a bundle of plates 50 forming an alternation of circulation channels 51 in which a refrigerant fluid FR circulates and circulation channels 53 in which a heat transfer liquid such as glycolated water circulates. The refrigerant fluid FR is for example, in a known manner, a hydro-fluoro-olefin (HFO) mixed with a low percentage of oil, less than 5% (percent) or even less than 3%.

[0030] The bundle of plates 50 is bordered at one of its ends comprising an inlet mouth 46 for refrigerant fluid of the heat exchanger 100, by a cheek 42, and at the other of its ends, by a closing plate 44 of the bundle of plates 50.

[0031] The inlet mouth 46 opens onto an inlet manifold 48 of the heat exchanger 100, extending around openings 541, 561 (referenced [Fig.2]) formed on each of the plates of the plate bundle 50, these openings delimiting a cylindrical zone 480 of central axis X crossing the plate bundle 50. The inlet manifold 48 serves the circulation channels 51 of refrigerant fluid.

[0032] As can be seen [Fig.2], the plate bundle 50 comprises two distinct types of plates, corresponding on the one hand to the plates referenced 54, all identical to each other, and on the other hand to the plates referenced 56, all identical to each other. The plate bundle 50 is formed by an alternation of plates 54 and 56 brazed together and two by two in contact with each other on flat portions of the inlet manifold 48, that is to say around the openings 541, 561 of the plates. In this way each pair of plates 54, 56 brazed together forms a partition between two circulation channels 51 at the level of the inlet manifold 48 of the heat exchanger 100. The pairs of plates 54, 56 forming this partition separate beyond the inlet manifold 48 to form the circulation channels 53 of heat transfer liquid, in a sealed manner relative to the circulation channels 51 of refrigerant fluid.

[0033] Each plate 54 comprises a mixing device 546 for the refrigerant fluid FR arriving through the opening 541 of the plate 54. This mixing device 546 is integral with the plate 54 and is more precisely obtained by stamping and semi-cutting the opening 541. It forms an edge of this opening 541 and projects into a space allowing the refrigerant fluid to enter the refrigerant fluid circulation channel 51, this space being between the plate and a plate 56 located opposite the plate 54 but at a distance from it in the inlet manifold 48.

[0034] This plate 56 also comprises a mixing device 566 for the refrigerant fluid FR obtained by stamping and semi-cutting an edge of the opening 561 of the plate 56, and projecting into a space allowing the entry of the refrigerant fluid into the refrigerant fluid circulation channel 51, this space being delimited by the plate 54 and this plate 56.

[0035] Each mixing device 546, 566 of a plate 54 or 56 takes the form of a helical turn with an axis equal to the central axis X of the cylindrical zone 480. A first angular portion 5662 (referenced [Fig. 4]) of the helical turn 566 forms an edge of the opening 561 of the plate 56, extending into the inlet manifold 48 in the direction of the central axis X while not detaching from the plate 56, i.e. without presenting radial access to the refrigerant fluid between this first angular portion 5662 and the rest of the plate 56. A second angular portion 5664 (referenced [Fig. 4]) of the helical turn 566, extending the first angular portion 5662, forms an edge of the opening 561 of the plate 56 extending into the inlet manifold 48 in the direction of the central axis X while detaching from the plate 56, that is to say that the refrigerant fluid FR can pass radially between the second angular portion 5664 and the rest of the plate 56.

[0036] Similarly, a first angular portion 5462 (referenced [Fig.5]) of the helical turn 546 forms an edge of the opening 541 of the plate 54, extending into the inlet manifold 48 in the direction of the central axis X while not detaching from the plate 54, i.e. without presenting radial access to the refrigerant fluid between this first angular portion 5462 and the rest of the plate 54. A second angular portion 5464 (referenced [Fig.5]) of the helical turn 546, extending the first angular portion 5462, forms an edge of the opening 541 of the plate 54 extending into the inlet manifold 48 in the direction of the central axis X while detaching from the plate 54, i.e. that the refrigerant fluid FR can pass radially between the second angular portion 5464 and the remainder of the plate 54.

[0037] Each helical turn 546 of a plate 54 joins at its angular end detached from the plate 54, an angular end detached from the plate 56 of a helical turn 566 of a plate 56. These two turns 546 and 566 which join are brazed together at these angular ends, more precisely on respective angular end surfaces 5465, 5665 (referenced figures 4 and 5) arranged orthogonally to the main extension plane of the cheek 42, and form a portion of helix.

[0038] In this way, the helical turn 546 of the plate 54 gives a rotational movement to a part of the refrigerant fluid FR coming into abutment against this helical turn 546. The second angular portion 5464 of this helical turn 546 makes it possible to deflect radially and angularly a part of the refrigerant fluid FR, in particular towards an upper part 482 (referenced [Fig.l]) of the inlet manifold 48, located opposite the bent ends of the refrigerant fluid circulation channels 51 as described later in relation to [Fig.3]. The helical coil 566 also receives a portion of refrigerant fluid FR coming into abutment against this helical coil 566 or driven by the aforementioned rotational movement, and also makes it possible to deflect radially and angularly around the central axis X a portion of the refrigerant fluid FR.

[0039] Each plate 54, 56 being provided with a helical turn 546, 566, these turns 546, 566 of the set of plates of the plate bundle 50 form a helix extending in the inlet manifold 48 along the central axis X.

[0040] [Fig. 3] representing in their entirety a plate 54 and a plate 56, allows a better understanding of the structure of the stack of plates forming the bundle of plates 50. In this [Fig. 3], the plate 54 has a face 540 intended to be brazed on a face 560 (referenced [Fig. 2]) of the plate 56, opposite a face 562 of the plate 56 shown in [Fig. 3]. In other words, the plate 56 is stacked and brazed above and in contact with the plate 54. Positioned in this way, the pair of plates 54, 56 forms a separating partition between two refrigerant circulation channels 51.

[0041] The plate 56 comprises on a main portion 57, flow disruptors 569 projecting from a flat surface of the face 560. These flow disruptors 569 extend orthogonally relative to this flat surface, up to the same level as a flat portion 59 of the plate 56 around the opening 561 of the inlet manifold 48. In other words, the main portion 57 is raised on the face 562 relative to the flat portion 59 around the opening 561 comprising the helical turn 566. A rim 5622 delimits the main portion 57 raised from the flat portion 59. The helical turn 566 extends orthogonally from this flat portion 59 to the same level as a flat surface of the main portion 57 located on the side of the face 562. When the plate 56 is pressed against the plate 54, the flat portion 59 all around the opening 561 is in contact with a corresponding flat portion 58 of the plate 54, around the opening 541 of the inlet manifold 48. The helical turns 561 and 541 of the respective plates 56 and 54 protrude on either side of these flat portions 58, 59 in contact with each other. The refrigerant fluid FR cannot therefore flow between the plates 54 and 56.

[0042] Similarly, a periphery of an opening 543 of the plate 54 forming part of an outlet manifold of the heat exchanger 100 is brazed in a sealed manner to a periphery of an opening 563 of the plate 56 forming part of this outlet manifold. The refrigerant FR cannot therefore pass from the outlet manifold to a circulation channel 53 of heat transfer liquid, located between the plate 54 and the plate 56. This contact between the peripheries of the openings 543 and 563 is permitted because the refrigerant outlet opening 563 is located on a portion of the plate 56 at the same level as the flat portion 59 comprising the opening 561 relative to the main portion 57 of the plate 56, while the opening 543 is located in the extension of the main portion 61 of the plate 54 without deviating orthogonally therefrom.

[0043] The plate 54 also comprises, on a main portion 61, flow disruptors 549 projecting from a flat surface of a face 542 (referenced [Fig.2]) of the plate 54, opposite the face 540 of the plate 54. These flow disruptors 549 extend orthogonally relative to this flat surface, at the same distance as the helical turn 546 of the plate 54 also projecting from the side of the face 542. Other types of disturbance elements can of course be provided instead of or in addition to these flow disruptors 549.

[0044] Unlike the plate 56, the flat portion 58 of the plate 54 around the opening 541 of the inlet manifold 48 is in the same plane as the main portion 61 taken without its relief elements (in particular the flow disruptors 549). This main portion 61 is however raised on the face 540 relative to a flat portion of the plate 54 comprising an opening 545 of a heat transfer liquid inlet collector of the heat exchanger 100, and relative to a flat portion of the plate 54 comprising an opening 547 of a heat transfer liquid outlet collector of the heat exchanger 100. The plate 56 comprises, opposite the opening 545, an opening 565 of the heat transfer liquid inlet collector and opposite the opening 547, an opening 567 of the heat transfer liquid outlet collector.These openings 565 and 567 on the plate 56 are located in the extension of the main portion 57 of the plate 56 without deviating orthogonally therefrom. In other words, the heat transfer liquid inlet openings 565 and 545 are located at a distance from each other and the heat transfer liquid outlet openings 567 and 547. The heat transfer fluid inlets 565 and 567 are located at a distance from each other. In this way, when the plate 56 is brazed to the plate 54, the heat transfer fluid arriving in the heat transfer fluid inlet manifold can circulate in the circulation channel 53 between the plates 54 and 56, and between the flow disruptors 569 of the plate 56 which impose a distance between the flat surface of the main portion 57 of the plate 56 located on the side of the face 560 and the flat surface of the main portion 61 of the plate 54 located on the side of the face 540. A groove 568 arranged on the face 562 of the plate 56 separates the heat transfer fluid inlet openings 565 and 567 for the heat transfer fluid outlet by extending from the middle of one edge of the plate 56 towards the opposite edge without reaching it.Thus the heat transfer fluid arriving through the heat transfer fluid inlet opening 545 of the plate 54 is forced to bypass the groove 568 before exiting through the heat transfer fluid outlet opening 547 of the plate 54, which makes it travel the entire length of the plate 54, the circulation channel 53 having a U shape, the bend of the U being arranged at one longitudinal end of the plate 56 opposite the heat transfer fluid openings 565, 567 of the plate 56. The refrigerant inlet manifold 48 and the refrigerant outlet manifold are located on the other longitudinal end of the plate 56.

[0045] Conversely, when a plate 54 is positioned on a plate 56, that is to say when the face 542 of the plate 54 is brazed onto the face 562 of the plate 56, the flat portion 58 of the plate 54 around the opening 541 of the inlet manifold 48 is at a distance from the flat portion 59 of the plate 56 around the opening 561 of the inlet manifold 48, the turns 546 and 561 of the two plates 54, 56 joining at their angular end surfaces 5465 and 5665. The refrigerant FR arriving through the opening 541 can therefore circulate between these plates 54 and 56 in a circulation channel 51 formed between these plates 54 and 56. The refrigerant FR then circulates between the flow disruptors 549 of the plate 54, which impose a distance between the flat surface of the main portion 61 of the plate 54 located on the side of the face 542 and the flat surface of the main portion 57 of the plate 56 located on the side of the face 562.

[0046] A groove 548 arranged on the face 540 of the plate 54 separates the opening 541 of the refrigerant inlet manifold 48 from the opening 543 of the refrigerant outlet manifold, extending from the middle of one edge of the plate 54 towards the opposite edge without reaching the latter. Thus, the refrigerant arriving through the refrigerant inlet opening 541 is forced to bypass the groove 548 before exiting through the refrigerant outlet opening 543 of the plate 54, which makes it travel the entire length of the plate 54, the circulation channel 51 having a U shape, the bend of the U being arranged at a longitudinal end of the plate 54 opposite the refrigerant openings 541 and 543, this longitudinal end being proximal to the edge of the plate 54 from which the groove 548 extends. The heat transfer liquid openings 545 and 547 of the plate 54 are located at an opposite longitudinal end of the plate 54.

[0047] The dimension of the flow disruptors 549 in a direction orthogonal to the cheek 42 is identical to the difference in level in this orthogonal direction, between on the one hand the portions of the plate 54 comprising the heat transfer liquid openings 545, 547 and on the other hand the flat surface of the main portion 61 of the plate 54 located on the side of the face 542. As a result, the peripheries of the heat transfer liquid openings 545, 547 of the plate 54 are entirely in contact with corresponding peripheries of the respective heat transfer liquid openings 565, 567 of the plate 56 which are located in the extension of the main portion 57 of the plate 56 without deviating orthogonally therefrom. As a result, the heat transfer fluid entering through the opening 545 of the plate 54 cannot pass into the refrigerant circulation channel 51, and the heat transfer fluid exiting through the opening 547 of the plate 54 cannot pass into the circulation channel 51 either.

[0048] It should be noted that the dimensions of the turns orthogonal to the planar portions 58 and 59 may be slightly different from those indicated here, given that the mixing devices 546, 566 operate even if they do not meet exactly at their respective angular end surfaces 5465 and 5665.

[0049] Returning to [Fig. 1], the refrigerant fluid FR arriving from a refrigerant fluid connection block 40 brazed to the cheek 42 of the heat exchanger 100, in the inlet mouth 46, is formed of a small percentage of oil, and of a refrigerant compound at 30% in the gaseous phase and at 70% in the liquid phase. The refrigerant fluid FR entering the inlet mouth 46 reaches the inlet manifold 48 through an opening arranged in a first plate 52 brazed to a first plate 54 of the plate bundle 50, proximal to the cheek 42 of the heat exchanger 100. This plate 52 makes it possible to form a first circulation channel 53 between this plate 52 and the first plate 54, without a helical spiral projecting from the plate 52 towards the cheek 42. In other words, the plate 52 is structurally identical to a plate 56 except for the fact that it does not include a mixing device.

[0050] A portion of the refrigerant fluid FR arriving in the inlet manifold 48 passes through this opening in the plate 52 as well as the openings 541 and 561 arranged in the plates 54, 56 of the plate bundle 50, up to the closing plate 44. This portion of the refrigerant fluid FR passing directly through the inlet manifold 48 circulates in a cylindrical passage 60 (referenced [Fig.2]) delimited by internal contours 544, 564 (referenced figures 4 and 5) of the respective helical turns 546 and 566 of each respective plate 54, 56.

[0051] The diameter of the cylindrical passage 60 is approximately 5 millimeters, the beam of plates 50 comprising 60 plates in this first embodiment of the invention. Alternatively, the diameter of the cylindrical passage is of a different value, between 4 and 8 millimeters, and the bundle of plates comprises between 30 and 70 plates. This diameter is smaller than the average dimension of an opening of an inlet manifold of the prior art, in order to allow the refrigerant fluid to easily reach the end of the inlet manifold 48 opposite the cheek 42 of the heat exchanger 100.

[0052] Other portions of refrigerant fluid FR diverge from the direction parallel to the central axis X and arrive in each of the refrigerant fluid circulation channels 51. This deviation of portions of the refrigerant fluid flow FR is facilitated by the respective helical turns 546 and 566 at the inlet of each circulation channel 51.

[0053] According to a second embodiment of the invention illustrated in Figures 6 and 8, a heat exchanger 10 according to the invention comprises a bundle of plates 20 bordered by a cheek 14 and a closing plate 16. A connection block 12 is secured to the cheek 14 and allows the entry of a refrigerant fluid FR into an inlet mouth 18 arranged in the cheek 14. This inlet mouth 18 opens onto an inlet manifold 11 of the heat exchanger 10. The bundle of plates 20 comprises an alternation of two types of plates, namely plates 24 and plates 26, which form an alternation of circulation channels 23 for heat transfer liquid and circulation channels 21 for refrigerant fluid.This arrangement of the heat exchanger 10 is structurally identical to that of the heat exchanger 100, only mixing devices 31 formed in openings 30 of the plates 24, 26 being of different structures from the mixing devices 546, 466 of the first embodiment of the invention.

[0054] In particular, the inlet manifold 11 comprises a cylindrical zone 110 delimited at least in part by the openings 30, and an upper part 112 opposite the bends of the circulation channels 21, 23, these bends themselves being arranged at a longitudinal end of the plates 24, 26. In addition, an inlet plate 22 not comprising a mixing device 31 is arranged against the cheek 14, in a similar manner to the plate 52 of the first embodiment of the invention.

[0055] The mixing device 31 of a plate 24 projects into a space between this plate 24 and a plate 26, this space allowing the refrigerant FR to enter a refrigerant circulation channel 21. The mixing device 31 of the plate 26 projects into the same space. The mixing devices 31 of the plates 24 and 26 therefore face each other in each circulation channel 21.

[0056] Each mixing device 31 comprises a foot 33 secured to the rest of the plate 24, 26 to which it belongs, by one of its ends, the other of its ends being connected to a head 35 of the mixing device cantilevered relative to the rest of the plate 24, 26. The heads 35 of the mixing devices 31 make it possible to divert the refrigerant fluid FR arriving through the inlet mouth 18 towards the circulation channels 21 or towards the upper part 112 of the collector 11 as represented by the arrows orthogonal to the direction given by the axis X which is the central axis of the cylindrical zone 110.

[0057] The heads 35 leave in the cylindrical zone 110, a cylindrical passage 15 allowing the refrigerant fluid FR to pass without obstacles through the inlet manifold 11 to the closing plate 16. This cylindrical passage 15 is for example 5 mm in diameter, the number of plates 24, 26 being approximately 60 plates.

[0058] Compared to a plate 2 without a mixing device and shown in [Fig. 7], the distribution of the refrigerant FR on a plate 24 (or 26) is improved, as shown in [Fig. 8]. In [Fig. 7], the refrigerant FR enters a refrigerant circulation channel delimited by the plate 2, through an opening 4 in the plate 2, goes around a groove 6 separating this opening 4 from a refrigerant outlet opening 8, then leaves the plate 2 through this outlet opening 8. The arrows formed by dots and dashes represent the flow of refrigerant FR on this plate 2, the thickness of the arrows being all the greater as the flow rate is high. It can be seen that at the periphery of plate 2, the flow of refrigerant fluid is of very low flow rate, as well as near groove 6. The distribution of refrigerant fluid in the circulation channel delimited by plate 2 is therefore not homogeneous.

[0059] On the plate 24 shown [Fig.8], the refrigerant fluid FR enters a channel of circulation 21 of refrigerant fluid delimited by the plate 24, by the opening 30 of the plate 24, goes around a groove 34 separating this opening 30 from a refrigerant fluid outlet opening 32, then comes out of the plate 24 through this outlet opening 32. The arrows formed of dots and dashes also represent the flow of refrigerant fluid FR on this plate 24, the thickness of the arrows being all the greater as the flow rate is high.

[0060] It can be seen that the heads 35 make it possible to divert a portion of the flow of refrigerant fluid FR toward the upper portion 112 of the inlet manifold 11, by distributing this deviation regularly angularly around the opening 30 of the plate 24. As a result, the flow of refrigerant fluid FR at the periphery of the plate 24 has a higher flow rate compared to that of the plate 2, and likewise the flow of refrigerant fluid FR near the groove 34 has a higher flow rate compared to that of the plate 2. The distribution of refrigerant fluid FR in the circulation channel 21 delimited by the plate 24 is therefore more homogeneous than the distribution of refrigerant fluid FR in the circulation channel delimited by the plate 2. The heat transfer of the heat exchanger 10 is therefore better than that of a heat exchanger of the prior art.

[0061] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the characteristics of the different embodiments or variants can be combined to achieve the invention, to the extent that these embodiments or variants are not incompatible with each other.

Claims

Claims

1. Heat exchanger (100, 10) comprising a bundle of plates (50, 20) forming a plurality of circulation channels (51, 21) for a refrigerant fluid (FR), and an inlet manifold (48, 11) for refrigerant fluid serving the circulation channels (51, 21), the inlet manifold (48, 11) comprising openings (541, 561, 30) in the plates (52, 54, 56, 22, 24, 26) of the bundle of plates (50, 20), the openings delimiting at least in part a cylindrical zone (480, 110) in the inlet manifold (48, 11), the heat exchanger (100, 10) comprising at least one mixing device (546, 566, 31) for the refrigerant fluid (FR) extending into the inlet manifold (48, 11) and integral with at least one of the plates (54, 56, 24, 26) of the plate bundle (50, 20), the mixing device (546,566) comprising at least a first mixing device (546) formed on an edge (544) of an opening (541) of a first plate (54) adjacent to a second plate (56), and a second mixing device (566) formed on an edge (564) of an opening (561) of the second plate (56), the first and second mixing devices (546, 566) projecting between the first plate (54) and the second plate (56).,

2. Heat exchanger (100, 10) according to claim 1, wherein the mixing device (546, 566, 31) comprises at least one deflection means (5464, 5664, 35) conducting the refrigerant fluid (FR) towards an upper part of the inlet manifold (48, 11).

3. A heat exchanger (100, 10) according to claim 1 or 2, wherein the mixing device (546, 566, 31) forms part of the edge (544, 564) of an opening in the plate (54, 56, 24), the mixing device (546, 566, 31) projecting into the cylindrical area (480, 110), extending radially towards a central axis (X) of the cylindrical area (480, 110).

4. Heat exchanger (100, 10) according to claim 3, wherein the mixing device (546, 566, 31) is obtained by stamping and / or semi-cutting the edge (544, 564) of the opening (541, 561, 30).

5. Heat exchanger (100, 10) according to claim 3 or 4, wherein the mixing device (546, 566, 31) comprises a foot (5462, 5662, 33) extending over an angular portion of the opening (541, 561, 30) while being connected to the plate (54, 56, 24), the mixing device (546, 566, 31) also comprising a head (5464, 5664, 35) extending the foot extending away from a portion of the edge of the opening located angularly at the same level as the head (5464, 5664, 35).

6. Heat exchanger (100) according to claim 5, wherein the mixing device (546, 566) extends over the entire edge (544, 564) of the opening (541, 561) and forms a helical turn whose axis coincides with the central axis (X) of the cylindrical zone (480), a first angular portion of the helical turn forming the foot (5462, 5662) and a second angular portion of the helical turn forming the head (5464, 5664).

7. Heat exchanger (100) according to claim 1, in which the first and second mixing devices (546, 566) join and together form a helix portion whose axis coincides with the central axis (X) of the cylindrical zone (480).

8. Heat exchanger (100) according to claim 7, in which the plate bundle (50) comprises an alternation of plates identical to the first plate (54) and plates identical to the second plate (56), the first and second mixing devices (546, 566) of the plates (54, 56) of this alternation forming a helix extending over the length of the refrigerant fluid inlet manifold (48) opposite the circulation channels (51).

9. Heat exchanger (100, 10) according to any one of claims 1 to 8, in which the inlet manifold (48, 11) comprises a transverse cylindrical passage (60, 15) to the circulation channels (51, 21), delimited at least in part by the mixing device.

10. A heat exchanger (100, 10) according to claim 9, wherein a diameter of the cylindrical passage (60, 15) is between 4 and 8 millimeters, the plate bundle (50, 20) comprising between 30 and 70 plates.

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