WO2018172644A1

WO2018172644A1 - Heat exchanger with a liquid/gas mixer device having a regulating channel portion

Info

Publication number: WO2018172644A1
Application number: PCT/FR2018/050454
Authority: WO
Inventors: Natacha Haik-Beraud; Philippe Grigoletto; Sophie LAZZARINI; Jean-Marc Peyron; Guillaume CARDON
Original assignee: L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude
Priority date: 2017-03-24
Filing date: 2018-02-27
Publication date: 2018-09-27
Also published as: FR3064346B1; FR3064346A1; CN110462331A; CN110462331B

Abstract

The invention relates to a heat exchanger (1) comprising a plurality of plates (2) arranged in parallel so as to define a first series of passages (10) for channelling at least one first fluid (F1) and a second series of passages (20) for channelling at least one second fluid (F2) which is to be brought into a heat-exchanging arrangement with at least said first fluid (F1), a mixer device (3) being arranged in said at least one passage (10) of the first series and comprising at least one first channel (31) for the flow of a first phase (61) of the first fluid (F1) in a longitudinal direction (z), at least one second channel (32) for the flow of a second phase (62) of the first fluid (F1), and a plurality of openings (34), each one fluidically connecting the first channel (31) to the second channel (32). According to the invention, the first channel (31) has a cross-section which is measured perpendicularly to the longitudinal direction (z) and can be varied according to said longitudinal direction (z).

Description

HEAT EXCHANGER WITH PROVIDER F LIQUID / GAS MIXER WITH REGULATORY CHANNEL PORTION

The present invention relates to a heat exchanger comprising series of passages for each of the fluids to be placed in heat exchange relationship, the exchanger comprising at least one mixing device configured to dispense at least one two-phase liquid / gas mixture into a series of passages.

In particular, the present invention can be applied to a heat exchanger which vaporizes at least one liquid-gas mixture flow rate, in particular a multi-component mixing flow rate, for example a hydrocarbon mixture, by heat exchange with at least one other fluid, for example natural gas.

The technology commonly used for a heat exchanger is that of brazed plate and finned aluminum exchangers, which make it possible to obtain very compact devices with a large exchange surface.

These exchangers comprise plates between which are inserted heat exchange waves, formed of a succession of fins or wavelength legs, thus constituting a stack of vaporization passages and condensation passages, some of which may be intended for vaporize refrigerant and the others to condense a caloric gas. The heat exchanges between the fluids can take place with or without phase change.

In order to ensure the proper functioning of a heat exchanger using a liquid-gas mixture, the proportion of liquid phase and gas phase must be the same in all the passages and must be uniform within the same passage.

The dimensioning of the exchanger is calculated assuming a uniform distribution of the phases, and therefore a single end of vaporization temperature of the liquid phase, equal to the dew point temperature of the mixture.

For a multi-component mixture, the end-of-vaporization temperature will depend on the proportion of liquid phase and gas phase in the passages. In the case of unequal distribution of the two phases, the temperature profile of the first fluid will therefore vary according to the passages, or even vary within the same passage. Due to this non-uniform distribution, it may then happen that the fluid or fluids in exchange relationship with the two-phase mixture have a temperature at the outlet of the exchanger greater than that expected, thereby degrading the performance of the heat exchanger.

A solution for distributing the liquid and gaseous phases of the mixture as uniformly as possible consists in introducing them separately into the exchanger and then mixing them together only inside the exchanger.

Document FR-A-2563620 describes such an exchanger in which a grooved bar is inserted in the series of passages intended to channel the two-phase mixture. This mixing device comprises separate channels for a liquid phase and a gas phase and an outlet for distributing the liquid-gas mixture to the heat exchange zone.

A problem that arises with this type of mixing device relates to the distribution of the liquid-gas mixture in the width of the passage incorporating the mixing device. In order to proceed to the mixing of the two phases, the mixing device generally comprises a first channel for the flow of a phase. This channel is provided with a series of orifices arranged along the channel, each orifice being in fluid communication with the second channel for the flow of the other phase. When the inlet of the first channel is supplied with fluid, the flow velocity of the fluid will tend to decrease as the fluid flows along the channel. This is because the fluid flow rate decreases as the ports are energized.

However, the orifices are generally machined perpendicular to the longitudinal direction of the fluid and are therefore less well fed when the fluid velocity is greater. The orifices arranged on the side of the inlet of the channel therefore tend to be underfed, while the orifices farthest from the inlet of the channel are supercharged. This results in an unequal introduction of the phase considered in the channel for the other phase, and from there a unequal distribution of the liquid-gas mixture in the width of the passage of the exchanger.

In order to minimize this phenomenon, one solution is to feed the channel considered by two opposite inputs of the channel in order to minimize the longitudinal velocity of the fluid. However, this solution is insufficient when one targets a very homogeneous distribution, especially when the processes are very sensitive to maldistribution.

Increase the number of channels is possible but has its limits also: from the point of view of the mechanical strength and soldering of the device, one can not multiply the number of channels too much.

The present invention aims to solve all or part of the problems mentioned above, in particular by providing a heat exchanger in which the distribution of the liquid and gaseous phases of a mixture is as uniform as possible, and without complicating excessively the structure of the exchanger, nor to increase its bulk.

The solution according to the invention is then a heat exchanger comprising a plurality of plates arranged parallel to one another so as to define a first series of passages for channeling at least one first fluid and a second series of passages for channeling at least one second fluid to be introduced. in heat exchange relation with at least said first fluid, a mixing device being arranged in said at least one passage of the first series and comprising:

at least one first channel for the flow of a first phase of the first fluid in a longitudinal direction,

at least one second channel for the flow of a second phase of the first fluid,

the first channel comprising several orifices connecting fuidically the first channel to the second channel,

characterized in that the first channel has a cross section, measured perpendicularly to the longitudinal direction, variable along said longitudinal direction.

Depending on the case, the exchanger of the invention may include one or more of the following technical characteristics: the first channel comprises at least one transverse section change in the longitudinal direction.

the first channel comprises a first input for a supply with the first phase and at least a first portion downstream of the first input, the cross section of the first channel at the first portion being greater than the cross section of the first channel at the first portion; level of the first entry.

the first portion comprises at least one recess formed in at least a portion of a wall of the first channel.

- The mixing device comprises a plurality of first channels succeeding in a lateral direction orthogonal to the longitudinal direction, said at least one recess opening into the first successive channel.

the first channel comprises a first input for a supply with the first phase and at least a first portion arranged downstream of the first input, the cross section of the first channel at the first portion being smaller than the cross section of the first channel; at the level of the first entry.

the first channel comprises a plurality of first portions arranged along the longitudinal direction.

said first several portions have different cross sections.

- The cross sections of said first several portions decrease in the longitudinal direction.

the first channel further comprises a second input for a supply with the first phase and at least a second portion arranged downstream of said second input, the cross section of the first channel at the second portion being smaller than the cross section of the first channel; first channel at the second entry.

the first channel comprises a plurality of second portions arranged along the longitudinal direction.

- The cross sections of said second portions decrease towards the first input. at least one orifice is arranged at the level of the first and / or second portions.

the first and / or second portions extend in the longitudinal direction.

the first channel comprises a first input for supplying said first channel with said first phase of the first fluid, said orifices being arranged downstream of the first input and forming a series of orifices comprising a first orifice arranged on the side of the first input of the first first channel and a last hole.

at least one orifice is arranged at each first first portion.

the first fluid is a refrigerant.

the second fluid is a circulating fluid.

According to another aspect, the invention relates to a method for dispensing a two-phase liquid / gas mixture into a heat exchanger according to the invention, as well as a method for exchanging heat between said mixture with two liquid / gas phases and at least one other fluid. The liquid-gas mixture may be a refrigerant or a heat sink.

The term "natural gas" refers to any composition containing hydrocarbons including at least methane. This includes a "raw" composition (prior to any treatment or wash), as well as any composition that has been partially, substantially, or wholly processed for the reduction and / or elimination of one or more compounds, including but not limited to limit, sulfur, carbon dioxide, water, mercury and some heavy and aromatic hydrocarbons.

The present invention will now be better understood thanks to the following description, given solely by way of nonlimiting example and with reference to the attached drawings, among which: FIG. 1 is a diagrammatic view, in a plane of section parallel to the plates of a heat exchanger, of part of a passage of a heat exchanger fed with a two-phase liquid-gas mixture in accordance with one embodiment of the invention; of the invention;

- Figure 2 is a schematic sectional view, along a plane perpendicular to that of Figure 1, an embodiment of a mixing device according to the invention;

Figure 3 is a schematic three-dimensional view illustrating an embodiment of a mixing device according to the invention;

- Figures 4 and 5 are three-dimensional schematic views illustrating embodiments of a mixing device according to the invention;

Figure 6 is a partial sectional view, along a sectional plane parallel to that of Figure 1, of another embodiment of a mixing device according to the invention;

Figure 7 is a partial sectional view, along a sectional plane parallel to that of Figure 1, of another embodiment of a mixing device according to the invention.

Figure 1 illustrates a heat exchanger 1 comprising a stack of plates 2 (not visible) which extend in two dimensions, parallel to a plane defined by the directions z and y. The plates 2 are arranged parallel to each other spacially and thus form a plurality of fluid passages in indirect heat exchange relationship via said plates.

Preferably, each passage has a parallelepipedal and flat shape. The gap between two successive plates is small in front of the length and the width of each successive plate.

The exchanger 1 may comprise a number of plates greater than 20, or even greater than 100, defining between them a first series of passages 10 for channeling at least a first fluid F1, and a second series of passages 20 (not visible in FIG. 1) for channeling at least a second fluid F2, the flow of said fluids taking place generally in the lateral direction y. The passages 1 0 of the first series can be arranged wholly or partly alternately or adjacent to all or part of the passages of the second series.

In a manner known per se, the exchanger 1 comprises distribution and evacuation means 40, 52, 45, 54, 55 configured to distribute the different fluids selectively in the passages 10, 20, as well as for discharging said fluids from said passages. 10, 20.

The tightness of the passages 10, 20 along the edges of the plates 2 is generally ensured by lateral and longitudinal sealing strips 4 fixed to the plates 2. The lateral sealing strips 4 do not completely close the passages 10, But advantageously leave fluid inlet and outlet openings in the diagonally opposite corners of the passages.

The openings of the passages 10 of the first series are arranged coincidentally one above the other, while the openings of the passages 20 of the second series are arranged in the opposite corners. The openings placed one above the other are joined respectively in collectors of semi-tubular form 40, 45, 50, 55, through which the distribution and evacuation of the fluids take place.

In the representation of FIG. 1, the semi-tubular collectors 50, 45 serve to introduce the fluids into the exchanger 1 and the semi-tubular collectors 40, 55 serve to evacuate these fluids from the exchanger 1.

In this embodiment, the supply manifold of one of the fluids and the exhaust manifold of the other fluid are located at the same end of the exchanger, the fluids F1, F2 thus flowing against the flow in the exchanger 1.

According to another variant embodiment, the first and second fluids can also flow cocurrently, the supply means for one of the fluids and the means for discharging the other fluid then being located at opposite ends of the fluid. exchanger 1.

Preferably, the direction is oriented vertically when the exchanger 1 is in operation. The first fluid F1 flows globally vertically and in the ascending direction. Other directions and meaning Fluid flow F1, F2 are of course conceivable, without departing from the scope of the present invention.

It should be noted that in the context of the invention, one or more first refrigerants F1 and one or more second fluids F2 of different natures can flow within the passages 10, 20 of the first and second series of the same exchanger.

Advantageously, the exchanger according to the invention implements a first fluid with two refrigerant F1 and a second fluid F2 calorigenic.

The distribution and evacuation means of the exchanger advantageously comprise distribution waves 51, 54, arranged between two successive plates 2 in the form of corrugated sheets, which extend from the inlet and outlet openings. The distribution waves 51, 54 ensure the uniform distribution and the recovery of the fluids over the entire width of the passages 10, 20.

In addition, the passages 1 0, 20 advantageously comprise heat exchange structures arranged between the plates 2. These structures have the function of increasing the heat exchange surface of the exchanger. In fact, the heat exchange structures are in contact with the fluids circulating in the passages and transfer heat flows by conduction to the adjacent plates 2, to which they can be fixed by soldering, which increases the mechanical strength of the exchanger.

The heat exchange structures also have a function of spacers between the plates 2, in particular during assembly by brazing of the exchanger and to prevent any deformation of the plates during the implementation of fluids under pressure. They also guide the flow of fluid in the passages of the exchanger.

Preferably, these structures comprise heat exchange waves 1 1 which advantageously extend along the width and the length of the passages 10, 20, parallel to the plates 2, in the extension of the distribution waves along the length of the passages 10, 20. The passages 10, 20 of the exchanger thus have a main portion of their length constituting the heat exchange portion proper, which is provided with a heat exchange structure, said main part being bordered by distribution parts packed with distribution waves 51, 54.

Figure 1 illustrates a passage 10 of the first series 1 configured to dispense a first fluid F1 in the form of a two-phase liquid-gas mixture. The first fluid F1 is separated in a separator device 6 into a first phase 61 and a second phase 62 introduced separately into the exchanger 1 via a lateral collector 30 and the collector 50. The two phases 61, 62 are then mixed with each other by means of a mixing device 3 arranged in the passage 10 and shown schematically in Figure 1. Advantageously, several passages 10, or even all of the passages 10 of the first series comprises a mixing device 3.

FIG. 2 is a diagrammatic sectional view, in a plane perpendicular to that of FIG. 1, of a mixing device advantageously consisting of a bar, or rod, housed in a passage 10.

In the illustrated configuration, the mixing device 3 comprises a plurality of first channels 31a, 31b, ... adapted for the flow of a first phase 61 of the fluid F1. The first channel or channels 31 extend in the longitudinal direction z.

It should be noted that the direction of extension of a channel or of a portion of a channel is understood to mean a direction of global extent, the walls of the channel or of the portion of the channel not necessarily being rectilinear in the direction longitudinal z.

Several orifices 34 fluidly connect said at least one first channel 31 to said at least one second channel 32.

Advantageously, several orifices 34 (only one visible in FIG. 2) follow one another in the longitudinal direction z. Note that the orifices 34 are not necessarily arranged in rectilinear alignment along the longitudinal direction z. In the illustrated example, the first phase 61 is liquid and the longitudinal direction z corresponds to the flow direction of the first phase 61 in the first channels 31a, 31b ... These orifices are arranged to connect fluidically the first channel 31 has at least one second channel 32 adapted for the flow of the second phase 62, in the illustrated example a second gas phase 62.

The first channels 31a, 31b ... and the second channels 32a, 32b, ... extend parallel to the plates 2. The orifices 34 of the different first channels 31a, 31b, ... may be arranged in staggered, as shown in Figures 3 to 5, which promotes a more homogeneous distribution of the first phase 61 in the second channels 32a, 32b, ...

Preferably, the mixing device 3 according to the invention extends in the section of the passage 10 over almost all, or even all, of the height of the passage 10, so that the mixing device is in contact with each plate 2a. , 2b forming the passage 10.

The mixing device 3 is advantageously fixed to the plates 2 by soldering.

The mixing device 3 is advantageously of parallelepipedal general shape.

The mixing device 3 may have, parallel to the longitudinal direction y, a first dimension of between 20 and 200 mm and, parallel to the lateral direction z, a second dimension of between 100 and 1400 mm.

According to the invention, the cross section of the first channel 31 varies along said longitudinal direction z.

Note that in the context of the invention, the cross section of the first channel 31 is the section of the first channel 31 measured in surface units, perpendicular to the longitudinal direction z. Thus, with reference to FIG. 2, the cross section of the first channel 31 is measured in a plane defined by the x and y directions.

The fact that the first channel has a cross section whose value varies according to the position considered along the z direction makes it possible to minimize or eliminate the variable speed effect along the z direction of the first channel described previously. . When the first phase 61 flows at a given speed, it is thus possible to modify or regulate it along the direction z, by adjusting the dimension of the cross section, in order to control the supply of the orifices 34 on the along the first channel 31. It follows a more uniform supply of orifices and therefore a more homogeneous distribution of the liquid-gas mixture in the width of the passage 1 0. This solution has the advantages of being simple to implement, not to change the size of the exchanger and not to complicate its structure.

The variation of the cross-section of the first channel 31 can be induced locally or progressively along the longitudinal direction z, along all or part of the first channel 31.

Preferably, the first channel 31 comprises at least one cross-sectional change occurring in the longitudinal direction z. This change may be abrupt or gradual and may consist of an increase or decrease in said cross section.

According to one embodiment of the invention, the first channel 31 comprises a first input 31 1 through which the first phase 61 is introduced, during operation of the exchanger, into the first channel 31. At least a first portion 310 of the first channel 31, located downstream of the first inlet 31 1, has a cross section greater than the cross section of the first channel 31 at the first inlet 31 1.

The arrangement of a channel portion 310 with an enlarged passage section in the path of the first phase 61 in the first channel 31 makes it possible to reduce its flow velocity and thus to promote its distribution in an orifice 34 arranged in or in downstream of said portion 310.

Thus, the first portion 310 may be shaped to induce a decrease in the flow rate of the first phase 61. In other words, the first portion 310 can be shaped so that when the first phase 61 flows at a first speed V1 from the first inlet 31 1, said portion 310 induces a decrease in the flow rate such that the phase 61 flows at a second speed V2, lower than V1, at said portion 310. It is thus possible to compensate for the greater speed effect at the input of the first channel 31.

Advantageously, the first channel 31 comprises a plurality of orifices 34 forming a series with a first orifice arranged on the side of the inlet 31 1 and a last orifice located on the side of the end opposite the inlet 31 1. A first portion 310 is preferably arranged at least at the first orifice. Note that the terms "upstream" and "downstream" are used with reference to the overall flow direction of the first phase 61 since the entry of the first channel 31 considered.

Alternatively or additionally, the first channel 31 may comprise at least a first portion 31 0 having a cross section smaller than the cross section of the first channel 31 at the first inlet 31 1.

Thus, the first portion 310 may be shaped to induce an increase in the flow velocity and, for example, to compensate the frictional pressure losses that may occur along the longitudinal direction z.

Preferably, the first section-modified portion 310 has a constant or near-constant cross section along the z direction.

Said first portion 310 advantageously extends in the longitudinal direction z.

The dimensioning, the number and the distribution of first portions 310 arranged in the same first channel 31 or in several first channels 31a, 31b, ... is adapted according to the desired fluid velocity profiles along the same channel and / or between several first channels arranged in the device 3.

Advantageously, at least one orifice 34 of the first channel 31 is arranged at or downstream of the first portion 310.

Figures 3 to 5 illustrate alternative embodiments of mixing devices 3 according to the invention wherein the first portion 310 has a cross section greater than that of the first inlet 31 1.

The increase in the cross section of the first channel 31 at the first portion 310 may result from an increase in the width of said first channel 31, measured along the longitudinal direction y and / or result from an increase in the depth of the first channel 31. first channel 31, measured in a direction x orthogonal to the directions y and z.

More specifically, and as illustrated in FIG. 4, the first channel 31 typically comprises a first input 31 1 for a supply with the first phase 61. The orifices 34 are arranged downstream of the inlet 31 1. If the channel 31 has a first cross-sectional value S1 given at the first input 31 1, said portion 310 has a second fluid passage section S2 larger than S1.

Preferably, the first portion 310 extends, in the longitudinal direction z, at least on either side of an orifice 34. It is thus possible to compensate for a change in flow velocity induced by the feed. an orifice 34 for supplying the next orifice 34 at an identical or almost identical speed.

Advantageously, the ratio S2 / S1 is greater than or equal to 1, 2, preferably between 1, 2 and 2, so as to significantly improve the distribution of the first phase 61 in the orifice or orifices 34 considered.

As seen in FIGS. 3 to 5, the mixing device 3 generally forms a parallelepiped delimited in particular by a first surface 3a intended to be arranged opposite a plate 2 of the exchanger and a second surface 3b arranged opposite Another plate 2. The first and second surfaces 3a, 3b preferably extend generally parallel to the plates 2. The mixing device 3 is preferably arranged in the passageway 10 so that the first and second surfaces 3a, 3b are located. in contact with the plates 2.

The first channels 31a, 31b are advantageously in the form of recesses whose length is large in front of the width, measured according to the lateral direction y or height, measured in a vertical direction x orthogonal to the directions y and z, of said canals.

The device 3 may comprise several lateral channels 32 succeeding one another within the device 3 and / or several first channels 31. Figures 3 to 5 illustrate a device 3 comprising a row of first channels 31 parallel to each other and a row of second channels 32 parallel to each other.

It being specified that the channels 31 and 32 may be of a shape and in a number that are distinct or identical. The first and / or second channels 31, 32 may be formed of internal recesses formed in the mixing device 3. They may also be open at the surfaces 3a and / or 3b and form main grooves 31, 32, as illustrated in Figures 3 to 5. The first and / or second channels 31, 32 may have cross sections of different shape, rectangular, circular or other, preferably rectangular cross sections .

According to one embodiment, the first portion 310 comprises a recess formed in at least a portion of a wall of the first channel 31.

Advantageously, at least one orifice 34 is arranged in said recess. The arrangement of an orifice 34 at the recess makes it possible, by virtue of the change of direction of flow of the fluid induced locally by the recess, to supply the orifice 34 with a reduced flow velocity and therefore better the supply, which is particularly advantageous for the orifices 34 located on the side of the inlet 31 1 of the channel 31.

Several recesses can be arranged in the same first channel 31 and / or in one or more first successive channels 31. Said recesses may have a cross section of rounded shape, rectangular or any other suitable form. The number of orifices placed in the recesses, as well as the shape and size of the recesses may be variable along the first channel 31. The realization of these recesses can for example be done by milling.

According to a particular configuration, at least one recess 310 formed in at least a portion of a wall of the first channel 31a opens into the first channel 31b in succession.

FIG. 3 represents an example of mixing device 3 in the form of a bar, openings 34 being pierced in the bottom of several first channels 31. The recess comprises a secondary groove 310 formed in the bottom wall of the first channel 31. Said secondary groove may extend along the channel, at the orifices, over all or part of the length of the channel.

Alternatively, the recess may be provided in one or more of the side walls of a plurality of first channels 31.

The bottom wall of the first channels 31 is preferably generally straight in the longitudinal direction z. 4 illustrates another example of mixing device 3 in which the recess is formed in a side wall of several first channels 31, thus forming a network of recesses 310. All or part of the orifices 34 can be arranged in these recesses. The turn followed by the flow of fluid at the entrance of the niches reduces the speed upstream of the orifices and facilitates the flow of flow to these orifices. In addition, the supply of an orifice 34 located in such niches is at a controlled flow rate that is that of the first phase 61 around the orifice, while minimizing or eliminating the variations in the flow rate of the first phase 61 flowing in the main part of the first channel 31.

These niches preferably have dimensions comparable to the width of the first channel 31 and are of considerable height vis-à-vis the height of the channel 31, said heights being measured in the direction x.

In the example illustrated in Figure 5, all or part of the orifices 34 is arranged in recesses of a first channel 31a, said niches being dimensioned such that they communicate with another immediately adjacent first channel 31b. A network of orifices 34 fed at reduced speed and in a more homogeneous manner is thus obtained. Several network configurations can be envisaged depending on the desired distribution.

Figures 6 and 7 illustrate alternative embodiments of mixing devices 3 according to the invention wherein the first portion 310 has a cross section smaller than that of the first inlet 31 1. In addition, the mixing devices 3 may have one or more of the features mentioned above.

Figure 6 is a partial view of an embodiment in which the first channel 31 comprises a plurality of first portions 310 having cross sections smaller than that of the first inlet 31 1.

Thus, the first portions 310 are shaped so as to induce a decrease in the passage section that compensates for the decrease in fluid flow as the successive orifices are fed. This tends to standardize the flow velocity of the fluid along the first channel 31 and thus a more homogeneous supply of orifices. According to a particular embodiment, the sections of fluid passages of the first portions 310 decrease in the longitudinal direction z.

As seen in Figure 6, the first channel 31 has a first cross section S1 at the inlet 31 1. The first phase 61 then flows at a first portion 310 having a second cross section S2 smaller than said first section S1. The first channel 31 may further comprise another first portion 310 arranged downstream of the first portion and having a third section S3 smaller than the second section S2.

Advantageously, the ratio of sections S2 / S1 and / or the ratio between two first successive portions 310 is less than or equal to 0.8, preferably between 0.5 and 0.8. This significantly improves the distribution of the first phase 61 in the orifice or orifices 34 considered.

As illustrated in FIG. 6, the reduction in the cross-section of the first channel 31 can result from a decrease in the width of the first channel 31, measured along the longitudinal direction y. Alternatively or additionally, it is also possible to envisage a reduction in the cross-section of the first channel 31 resulting from a decrease in its height, measured in the vertical direction x.

FIG. 7 partially illustrates another embodiment of the invention that is particularly advantageous when the first channel 31 has two inputs for supplying the first phase 61. More specifically, the first channel 31 comprises a first input 31 1 and a second input 312 for the injection of the first phase 61. The second input is preferably arranged at a second end of the first channel located opposite a first end comprising the first input 31 1.

The first channel 31 comprises at least a second portion 313 arranged downstream of said second inlet 312, the cross section of the first channel 31 at the second portion 313 being smaller than the cross section of the first channel 31 at the second inlet 312.

Thus, the flow rate of the first phase 61 is better adapted as it flows, so as to progressively compensate for the variation in the flow rate during the passage of the first phase. first phase 61 above the orifices 34 succeeding one another along the first channel 31.

Preferably, the first channel 31 comprises a plurality of second portions 313 arranged along the longitudinal direction z. The cross sections of said second portions 313 decrease towards the first inlet 31 1.

Advantageously, the ratio between the sections of the first channel 31 at the second portion 313 and the second inlet 312 and / or the ratio between two successive second portions 313 is less than 0.8, preferably between 0.5 and 0.8.

FIG. 7 illustrates the case where the first and second portions 310, 313 are arranged symmetrically with respect to the center of the first channel 31. Said portions could, however, be arranged in different numbers and have different cross sections on either side of the center of the first channel 31.

Of course, the invention is not limited to the particular examples described and illustrated in the present application. Other variants or embodiments within the reach of those skilled in the art can also be envisaged without departing from the scope of the invention.

For example, the exchanger according to the invention is mainly described in the case where the passages 10, 20 extend in the longitudinal direction y, the first longitudinal channel 31 extending in the longitudinal direction z and the lateral channel 32 s extending in a lateral direction y orthogonal to the longitudinal direction z. The opposite is also conceivable, that is to say a first longitudinal channel 31 extending in the lateral direction y and a lateral channel 32 extending in the longitudinal direction z. The lateral y and longitudinal z directions may also not be orthogonal to each other.

Claims

1. Heat exchanger (1) comprising a plurality of plates (2) arranged parallel to one another so as to define a first series of passages (10) for channeling at least a first fluid (F1) and a second series of passages (20) for channeling at at least one second fluid (F2) to be in heat exchange relation with at least said first fluid (F1), a mixing device (3) being arranged in said at least one passage (10) of the first series and comprising:

at least one first channel for the flow of a first phase of the first fluid, said first channel extending in a longitudinal direction,

at least one second channel (32) for the flow of a second phase (62) of the first fluid (F1),

a plurality of orifices (34) fluidly connecting the first channel (31) to the second channel (32),

characterized in that the first channel (31) has a cross section, measured perpendicularly to the longitudinal direction (z), variable along said longitudinal direction (z).

2. Exchanger according to claim 1, characterized in that the first channel (31) comprises at least one cross-sectional change in the longitudinal direction (z). 3. Exchanger according to one of claims 1 or 2, characterized in that the first channel (31) comprises a first inlet (31 1) for a supply with the first phase (61) and at least a first portion (310) downstream of the first inlet (31 1), the cross section of the first channel (31) at the first portion (310) being greater than the cross section of the first channel (31) at the first inlet (31 1). ).

4. Exchanger according to one of the preceding claims, characterized in that the first portion (310) comprises at least one recess formed in at least a portion of a wall of the first channel (31).

5. Exchanger according to claim 4, characterized in that the mixing device (3) comprises a plurality of first channels (31a, 31b, ...) succeeding in a lateral direction (y) orthogonal to the longitudinal direction (z) , said at least one recess opening into the first channel (31b) successive. 6. Exchanger according to one of claims 1 or 2, characterized in that the first channel (31) comprises a first inlet (31 1) for a supply with the first phase (61) and at least a first portion

(310) arranged downstream of the first inlet (31 1), the cross section of the first channel (31) at the first portion (310) being smaller than the cross section of the first channel (31) at the first Entrance

(31 1).

7. Exchanger according to one of claims 3 to 6, characterized in that the first channel (31) comprises a plurality of first portions (310) arranged along the longitudinal direction (z).

8. Exchanger according to claim 7, characterized in that said plurality of first portions (310) have different cross sections.

9. Exchanger according to one of claims 6 to 8, characterized in that the cross sections of said first plurality of portions (310) decrease in the longitudinal direction (z). 10. Exchanger according to one of claims 3 to 9, characterized in that the first channel (31) further comprises a second inlet (312) for a supply with the first phase (61) and at least a second portion (313 ) arranged downstream of said second inlet (312), the cross section of the first channel (31) at the second portion (313) being less than the cross section of the first channel (31) at the second inlet (31 2).

1 1. Exchanger according to claim 10, characterized in that the first channel (31) comprises a plurality of second portions (313) arranged along the longitudinal direction (z).

12. Exchanger according to claim 1 1, characterized in that the cross sections of said second portions (313) decrease towards the first inlet (31 1).

13. Exchanger according to one of claims 3 to 12, characterized in that at least one orifice (34) is arranged at the first and / or second portions (31 0, 313).

14. Exchanger according to one of claims 3 to 13, characterized in that the first and / or second portions (310, 313) extend in the longitudinal direction (z).