WO2020239767A1

WO2020239767A1 - Exchanger-reactor with improved distribution areas

Info

Publication number: WO2020239767A1
Application number: PCT/EP2020/064578
Authority: WO
Inventors: Nicolas GALLIENNE; Matthieu FLIN; Sébastien CADALEN; Olivier Dubet
Original assignee: L'air Liquide Société Anonyme Pour L’Étude Et L'exploitation Des Procédés Georges Claude
Priority date: 2019-05-29
Filing date: 2020-05-26
Publication date: 2020-12-03
Also published as: FR3096768A1; FR3096768B1

Abstract

The invention relates to an exchanger-reactor or an exchanger comprising a plurality of walls (12) stacked in a stacking direction (z) which is orthogonal to a longitudinal direction (x) and to a lateral direction (y) so as to define at least a first series of stages therebetween (10). Each stage (10) is divided, in the longitudinal direction (x), into at least one exchange area (4) and at least one distribution area (3, 5) arranged upstream and/or downstream of the exchange area (4), with connection interfaces (43, 45) each arranged between the exchange area (4) and the distribution area (3, 5), the exchange area (4) comprises a plurality of exchange channels (41) defined by partitions (46) which extend continuously between the two connection interfaces (43, 45), and the at least one distribution area (3, 5) comprises a plurality of distributor channels (31, 51) which each connect a fluid inlet (33) interface and/or fluid outlet (55) interface arranged on a longitudinal edge (10a) of the stage (10) with a connecting interface (43, 45) so as to convey the first fluid (F1) to the exchange channels (41) and/or from the exchange channels (41), respectively, each distributor channel (31, 51) being defined by at least one guideline (dm) which extends between the fluid inlet interface and/or outlet interface (33, 55) and a connecting interface (43, 45) and which is a homothetic curve of the outer contour (D) with a predetermined homothetic ratio (km), and a plurality of protrusions (9) being arranged along each guideline (dm) and extending between the pair of adjacent walls (12), the protrusions (9) being capable of changing at least one flow direction of the first fluid (F1) and each having, in cross section in a plane parallel to the longitudinal (x) and lateral (y) directions, a wing-shaped hydrodynamic profile.

Description

DESCRIPTION

Title: Exchanger-reactor with improved distribution zones

The present invention relates to the field of exchangers-reactors or exchangers.

In particular, the invention can be applied to an exchanger-reactor intended for carrying out endothermic or exothermic catalytic reactions.

The invention finds applications in several processes. It can be used in particular as an exchanger-reactor in reactions of the reforming type of hydrocarbons such as methane for the production of synthesis gas (called "syngas") rich in hydrogen, or as an exchanger in processes. oxycombustion to preheat oxygen.

A commonly used technology is that of brazed plate and fin heat exchangers, which make it possible to obtain very compact devices offering a large exchange surface.

These exchangers include plates between which are inserted heat exchange structures defining exchange channels, thus constituting a stack of stages where the various fluids circulate to be placed in indirect heat exchange relationship via the plates.

A technology of exchangers or exchanger-reactors inspired by plate exchangers is that of structured exchanger-reactors. These reactor-exchangers comprise a stack of walls superimposed on one another and delimiting between them several series of stages of generally flat shape. These stages include fluid guide structures delimiting, depending on the type of stage, exchange channels, or reactive channels, where the chemical reaction takes place, or heat transfer channels to supply or remove the calories necessary for or produced by the reaction.

The channels can be formed by machining the walls or else be formed in the free space between the walls, the space being structured by partitions or studs inserted between the walls.

In a known manner, the stages of the exchangers-reactors or of the exchangers comprise so-called distribution zones arranged, following the overall direction fluid flow in the stage considered, upstream and downstream of the actual reaction and / or heat exchange zone. The distribution zones are fluidly connected to collectors, generally of semi-tubular shape, configured to distribute the various fluids selectively in the appropriate stages, as well as to evacuate said fluids from said passages. In the following, the term “distribution zone” will denote a zone intended for the introduction of fluids into the exchanger or intended for the evacuation of fluids outside the exchanger. The term “exchange zone” will also denote a zone where a heat exchange and / or a chemical reaction takes place. The term “exchanger” may designate an exchanger or a reactor-exchanger.

In a known manner, the distribution zones comprise structures, such as fins, partitions, studs, which ensure the deflection of the fluid coming from the inlet manifold of the exchanger in order to distribute it over the width of the exchange zones. , as well as the recovery of the fluid from the exchange zone. These structures also act as spacers between the walls to ensure the mechanical strength of the distribution area.

One problem that arises with the configuration of current distribution areas is the poor distribution of fluids to or from the heat exchange areas. Poor design of distribution area structures can lead to variations in pressure drop and flow rate across the width of the heat exchanger-reactor, affecting its thermal efficiency and proper operation.

Another problem relates to the mechanical strength of the distribution zones. Indeed, these areas are generally provided with distributed structures with lower densities than that of the exchange areas. Since the distribution zones are parts where the thermal performance is lower compared to those of the heat exchange zones, it is desirable to configure the structures in an adequate way and to limit as much as possible the longitudinal extent of the distribution zones, while by ensuring a good compromise between thermal performance and resistance of the exchanger during the circulation of pressurized fluids within the stages. However, reducing the size of the distribution areas tends to make the guiding of the fluid flows in these areas more critical.

The object of the present invention is to provide an exchanger-reactor or an exchanger in which the distribution of the fluids in the reaction and / or exchange zones is as uniform as possible, in order to guarantee good homogeneity. heat exchanger-reactor, and which also has more compact distribution zones and better mechanical strength than in the prior art.

A solution according to the present invention is then an exchanger-reactor or exchanger comprising a plurality of walls stacked in a stacking direction z which is orthogonal to a longitudinal direction x and to a lateral direction y, so as to define between them at least a first series of stages configured for the flow of a first fluid and a second series of stages (configured for the flow of a second fluid to be placed in indirect heat exchange relation with the first fluid, in which :

- each floor of the first series is defined between a pair of adjacent walls, a pair of longitudinal edges parallel to the longitudinal direction and a pair of side edges parallel to the lateral direction,

- each stage is divided, in the longitudinal direction, into at least one exchange zone and at least one distribution zone arranged upstream and / or downstream of the exchange zone, with connection interfaces each arranged between the exchange zone and said distribution zone,

- said exchange area comprises a plurality of exchange channels delimited by partitions which extend continuously between the two link interfaces, and

- Said at least one distribution zone comprises a plurality of distributor channels which each connect a fluid inlet and / or fluid outlet interface arranged on a longitudinal edge of the stage with a connecting interface so as to convey the first fluid respectively to the exchange channels and / or from the exchange channels,

characterized in that said at least one distribution zone has, in a plane parallel to the longitudinal and lateral directions, a surface distribution section Sdistrib delimited by a connecting interface, a fluid inlet or outlet interface and a contour curved outer,

each distributor channel being delimited by at least one guideline which extends between the fluid inlet and / or outlet interface and a connecting interface and which is a homothetic curve of the external contour with a predetermined homothety ratio , and

a plurality of protuberances being disposed along each guideline and extending between the pair of adjacent walls, said protrusions being adapted to changing at least one direction of flow of the first fluid and each having, in section in a plane parallel to the longitudinal and lateral directions, a wing-shaped hydrodynamic profile delimited by a leading edge, said leading edge being arranged so as to face the first fluid as it flows through the distribution zone, a trailing edge arranged downstream of the leading edge in the direction of flow of the first fluid, a first flow guide line and a second flow guide line interconnecting the leading edge and the leading edge, at least one of said first and second guide lines being curved towards the outer profile.

Depending on the case, the invention may include one or more of the following characteristics:

- The walls extend substantially parallel to each other and parallel to a plane defined by the longitudinal direction and the lateral direction.

- the leading edge and the trailing edge have a rounded shape, preferably convex.

- the first flow guide line and the second flow guide line are curved towards the outer profile.

- one of the first and second guide lines is curved in a direction opposite to the outer profile.

the leading edge and the trailing edge are connected by a segment defining a maximum length of the hydrodynamic profile called chord length, said segment connecting one end of the leading edge and one end of the trailing edge with said ends located on the guideline.

- the hydrodynamic profile has a chord length between the length of the guideline divided by the number of protuberances on said guideline and said length of the guideline divided by three times said number of protuberances and a maximum thickness between 5% and 10% of the chord length, the maximum thickness being defined as the maximum distance measured between the first flow guide line and the second flow guide line.

- at least one protuberance has a variation of at least one dimension chosen from its chord length, its maximum thickness, for example relative to a respective dimension of at least one other protuberance 9 of the distribution zone.

- the protuberances of the same guideline have hydrodynamic profiles with increasing chord lengths towards the connecting interface, and / or the protrusions have hydrodynamic profiles having maximum thicknesses decreasing along at least one line director in the direction of the link interface.

- The protuberances have hydrodynamic profiles of the “airplane wing” type, preferably of the “NACA” type, the first flow guide line forming a first so-called “upper surface” camber of said profile and the second guide line d 'flow forming a second so-called “intrados” camber of said profile and the hydrodynamic profile having a median camber located at any point of its length at an equal distance from the extrados and the intrados, said median camber connecting one end of the edge of attack and one end of the trailing edge located on the guideline.

the protrusions have hydrodynamic profiles of the non-symmetrical arched NACA type comprising a first domed arch and a second hollowed out arch, with the first domed arch oriented towards the external contour.

- the distribution zone comprises a plurality of guidelines arranged homothetically to each other from a center of homothety towards the external contour, the center of homothety being located at the intersection between the link interface and the interface d fluid inlet or outlet.

the distribution zone comprises a number M of distributor channels, M being an integer greater than 1, said channels having, at the level of the fluid inlet or outlet interface, first substantially identical dimensions, and having, at the level of the fluid inlet or outlet interface, level of the connection interface, of second substantially identical dimensions, said first and second dimensions being measured along the longitudinal (x) and lateral direction respectively, the distribution zone comprising a plurality of guidelines each referenced by an index m, m being a number integer ranging from 1 to M-1, each directing line being a homothetic curve of the external contour with a homothety ratio k _m = m / M.

- the external contour is elliptical or parabolic in shape.

- the link interface has a first length measured in the lateral direction and the fluid inlet or outlet interface has a second length measured in the longitudinal direction, the link interface and the inlet interface, or of fluid outlet being dimensioned according to a ratio R = L _y / L _x between 2 and 5, the exchange zone comprising a number N of exchange channels and the distribution zone comprising a number M of distributor channels with preference M = N / R.

- the protuberances totaling an overall section defined as the sum of the areas of the cross sections of each protuberance measured in a plane parallel to the longitudinal direction and parallel to the lateral direction, with a ratio S9 / S _Di s _t ri _b of at least 2%, preferably less than 30%, more preferably between 4 and 20%.

- A first fillet is provided at the level of at least one junction between a protuberance and a wall and / or a second fillet is provided at the level of at least one junction between a protuberance and a partition delimiting a exchange channel, said first and second fillets having radii of curvature between 0.2 mm and the half-height of the floor, said height being measured in a direction of stacking of the walls which is orthogonal to the longitudinal direction and lateral direction.

- that at least the walls, the exchange channels, the distribution channels, the protuberances are formed integrally by an additive manufacturing process, preferably a laser melting process on a metal powder bed.

the protuberances each having, in section in a plane parallel to the longitudinal direction and to the stacking direction, a front face and a rear face inclined at an angle with respect to the stacking direction, preferably an angle included between 5 and 40 °.

According to another aspect, the invention relates to a process for producing synthesis gas using a heat exchanger-reactor according to the invention. Of preferably, it is a process for reforming hydrocarbons to produce synthesis gas rich in hydrogen. In this case, a stream comprising hydrocarbons is used as the first fluid to feed the first series of stages, the exchange channels of which are covered with a catalyst, then forming reactive channels. The first fluid, preferably comprising methane and water vapor, reacts with the catalyst to produce synthesis gas. The heat input necessary for this endothermic reaction is obtained by circulating a second coolant, such as combustion fumes, nitrogen, air or water, in the stages of the second series which comprise heat transfer channels in indirect heat exchange relationship via a wall with the adjacent reactive channels. Preferably, the second heat transfer fluid enters the exchanger at a temperature between 700 and 1200 ° C and leaves it at a temperature between 450 and 700 ° C.

Note that a "channel" can be any type of hydraulic passage suitable for the circulation or guidance of a fluid and may have any shape of cross section, in particular circular or other, and be delimited by continuous or discontinuous walls.

The invention will now be better described thanks to the appended figures, provided by way of illustration and not by way of limitation, among which:

Fig. 1 shows a general view of a heat exchanger-reactor according to one embodiment of the invention.

Fig. 2 shows a superposition of several types of stages of an exchanger-reactor according to Fig. 1.

Fig. 3 shows an example of three stages of an exchanger according to Fig. 1.

Fig. 4 shows a stage of an exchanger-reactor or of an exchanger according to one embodiment of the invention.

Fig. 5 shows a distribution zone connected to a portion of an exchange zone in a stage of a heat exchanger-reactor or of an exchanger according to one embodiment of the invention.

Fig. 6 is an enlarged view of FIG. 5.

Fig. 7 shows a protuberance according to one embodiment of the invention.

Fig. 8 shows protrusions according to one embodiment of the invention.

Fig. 9 shows protrusions according to one embodiment of the invention.

Fig. 10 shows protuberances according to one embodiment of the invention. Fig. 1 is a three-dimensional view of a heat exchanger-reactor according to an embodiment of the invention which can be used for the implementation of a process for producing hydrogen by steam reforming. A first fluid F1, for example a mixture of methane and water vapor, enters the exchanger via an inlet connector 2 and leaves it via an outlet manifold 6. These collectors (or heads) are generally provided with inlet and outlet connectors 1 and 7 ensuring the fluidic links with the other equipment of the production installation.

The exchanger has three dimensions: length, measured in the longitudinal direction x, width, measured in the lateral direction y, and height, measured in the stacking direction z of the walls 12 of the exchanger (not visible in FIG. 1). ). The exchanger comprises at least a first series of stages 10 and a second series of stages 1 1 superimposed on each other in the stacking direction z. Preferably, the floors extend substantially parallel to each other and to a plane defined by the x and y directions. Each stage is delimited between two adjacent walls 12, a pair of side edges arranged parallel to the lateral direction y and a pair of longitudinal edges arranged parallel to the longitudinal direction x. Preferably, the walls 12 extend generally parallel to each other and parallel to the longitudinal direction x and to the lateral direction y, said longitudinal and lateral directions being orthogonal to each other.

Note that several exchangers or exchanger-reactors in one piece can be welded together in order to obtain a larger exchanger or exchanger-reactor.

The collectors 6, 7 are configured so as to evacuate all of the stages 10 of the first series in the first fluid F1 and to recover said first fluid F1 from these stages. The manifolds 2, 6 can be welded to the parallelepipedal body of the heat exchanger or of the heat exchanger-reactor or else, advantageously, be directly manufactured with the body of the heat exchanger to obtain a part without an assembly interface, preferably by an additive manufacturing process.

A second fluid F2 circulates in stages 1 1 of the second series. The flow of the first and second fluids occurs generally parallel to the x flow direction, preferably the first and second fluids flow countercurrently.

The second fluid F2 is typically a heat transfer fluid. It allows, in the case of a hydrocarbon reforming process such as methane steam reforming, to provide the heat input necessary for the chemical reaction which takes place in the stages 10 of the first series in which the first reactive fluid F1 circulates.

In addition, the exchanger-reactor according to the invention may include a third series of stages 15 interposed between stages 10, 1 1 of the first and second series. These stages 15 may be intended in particular for the circulation of a third fluid F3 which is preferably formed by the product of the chemical reaction carried out in stages 10, preferably synthesis gas rich in hydrogen. Preferably, the reactor exchanger comprises fluidic connection means connecting at least one stage 10 of the first series with a stage 15 of the third series.

The stages 10, 11 of the first and second series can be positioned alternately but not necessarily, it being understood that at least part of the stages 11 are adjacent to a stage 10.

Fig.2 shows an example of a possible arrangement of different types of stages 10, 1 1, 15 of an exchanger-reactor according to Fig.1. Such an order of arrangement of floors can be used to recover heat from products. This sequence of stages can be reproduced one or more times in the z direction.

Fig. 4 shows a stage 10 of the first series according to one embodiment of the invention. This stage is delimited by two walls 12, two longitudinal edges 10a and two lateral edges 10b

The first fluid F1 enters the body of the exchanger or the exchanger-reactor through the inlet manifold 2 then passes through a distribution (inlet) zone 3 arranged upstream of an exchange zone 4 and making it possible to ensure a homogeneous distribution of the fluid over a plurality of exchange channels 41 arranged across the width of the exchange zone 4, in order to guarantee the good performance of the equipment.

Preferably, the exchange channels 41 are delimited by rectilinear partitions 46 (see Fig. 6) which extend parallel to the longitudinal direction x. Preferably, said partitions 46 extend between two adjacent walls 12 over the entire height h of a floor, so as to be in contact with, or even merge with, said walls, said height being measured parallel to the stacking direction z ( see Fig. 2).

The fluid passes through the exchange zone 4 and is collected in a distribution (output) zone 5 arranged downstream of said exchange zone 4. The output distribution zone 5 operates in conjunction with the distribution zone of inlet 3 and is designed to ensure homogeneous recovery of the fluid from the exchange channels 41 of the exchange zone 4. The fluid leaves the body of the exchanger or of the exchanger-reactor via an outlet head 6 via the outlet connector 7.

The distribution zone 3 located at the entrance to the exchanger is delimited in particular by an input interface 33 and a connection interface 43 between the distribution zone 3 and the exchange zone 4. The connection interface 43 typically marks the end of the distribution channels 31 and the start of the exchange channels 41.

The distribution zone 5 located at the outlet of the exchanger is delimited in particular by an output interface 55 and a connection interface 45 between the distribution zone 5 and the exchange zone 4. The connection interface 45 typically marks the end of the exchange channels 41 and the start of the distribution channels 51.

Preferably, the input 33 and output 55 interfaces have a rectilinear shape aligned with a longitudinal edge 10a.

Preferably, the connecting interfaces 43, 45 have a rectilinear shape and extend parallel to a side edge 10b.

Fig. 3 is a partial exploded view of three types of stages 10, 1 1, 15 intended to be superimposed in a heat exchanger-reactor according to FIG. 1. Preferably, each stage 15 of the third series is also divided, along the longitudinal x direction, into a circulation zone comprising circulation channels 151, preferably rectilinear, and at least one distribution zone comprising distribution channels 155. De preferably, each stage 1 1 of the second series also comprises circulation channels 1 1 1 rectilinear which extend parallel to the longitudinal direction x.

Note that the present invention relates to the inlet and / or outlet distribution zones of the exchanger and applies in the same way for these two types of zones.

In addition, the exchanger according to the invention may comprise a third series of stages 15 according to the invention and therefore comprise at least one distribution zone configured according to the same principles as a distribution zone of a stage 10 of the first series. All of the possible characteristics of the invention detailed below are therefore applicable but will not be repeated in detail for the sake of brevity.

Fig. 5, Fig. 6 and Fig. 7 illustrate in detail the characteristics of a distribution zone 3 according to the invention, which is an entrance zone in the example illustrated. Fig. 6 is a more detailed view of FIG. 5. Zone 3 has a surface distribution section Sdistrib delimited between the connection interface 43 with the exchange zone 4, the input interface 33 and an external contour D of arcuate shape, which extends in a plane parallel to the longitudinal x and lateral y directions and connects the interfaces 43 and 33. It is in this section of the distribution zone that the distribution channels 31 are made.

The input interface 33 has a first length L _x measured along the longitudinal direction x, and the link interface 43 has a second length L _y measured along the lateral direction y. As it is desired to limit the longitudinal extent of the distribution zone, for the reasons already mentioned, the first length L is preferably greater than the second length _y , preferably in a ratio R of between 2 and 5. Due to the bend. that the first fluid must perform when it flows to or from the exchange zone, it becomes critical to control the distribution of the fluid so that it supplies the exchange zone 4 uniformly over its entire width, while ensuring sufficient mechanical strength. This is what the present invention aims to improve.

Each distributor channel 31 is delimited by at least one guideline d _m . For example, the channels 31 located at the ends of the distribution zone 3 are delimited either between the contour D and a guideline, or between a guideline, the interface 43 and the interface 33. The other channels 31 are delimited by two adjacent guidelines.

According to the invention, each guideline d _m is a homothetic curve of the external contour D with a predetermined homothety ratio k _m . A plurality of protuberances 9 are arranged along each directing line d _m and extend between the pair of adjacent walls 12 forming the stage 10 considered, over the entire height of the stage 10. The protrusions 9 form distinct entities spaced from each other.

As shown in Fig. 7, each protuberance 9 has, in section in a plane parallel to the x and y directions, a hydrodynamic profile delimited by a leading edge 92 of rounded shape, preferably convex, a trailing edge 97, a first guide line d flow 96 and a second flow guide line 99, said lines connecting the leading and trailing edges.

By "leading edge" is meant a portion of the profile located at an upstream end, following the flow of the fluid, of said profile and which is arranged so as to face the first fluid F1 when it flows in the distribution zone considered.

By "trailing edge" is meant a portion located at a downstream end of the profile, following the direction of flow of the first fluid F1, that is to say the rear portion of the profile in the direction of flow.

The arrangement of protuberances in the distribution zone according to the invention makes it possible to ensure efficient guidance of the fluid from and to the exchange zone while consolidating the distribution zone thanks to an efficient support of the walls 12. The distribution of the protuberances along curves arranged homothetically to each other allows a homogeneous distribution of the protuberances and therefore good mechanical strength. The mechanical stresses are distributed over the entire Sdistrib surface of the distribution zone.

The use of hydrodynamic profiles with at least one curved guide line makes it possible to properly orient the flow of the first fluid and to reduce the disturbances that the protrusions could generate 9.

Advantageously, the first guide line 96 and the second guide line 99 are curved in the direction of the outer profile D, as in the example of FIG. 7. This makes it possible to orient the leading edge with the flow of the incident fluid and to direct the fluid in the desired direction with a gradual change of direction in order to limit the pressure losses.

Preferably, the trailing edge 97 also has a rounded shape, preferably convex. Having hydrodynamic profiles devoid of sharp edges optimizes the flow in the distribution area while limiting the impact on the mechanical resistance of the latter.

Preferably, the leading edge 92 includes an end point 92a at which the flow is divided into two portions, each passing through one side of the profile. This end point 92a may be a point on the profile where the fluid first impacts the protuberance.

According to one embodiment (see FIG. 7), the leading edge 92 and the trailing edge 97 comprise ends 92a, 97a connected by a segment C defining a maximum length of the hydrodynamic profile called the chord length L _c . The ends 92a, 97a are located on the guideline d _m considered.

Another characteristic dimension of the protuberance profiles 9 may be the maximum thickness e of the profile, illustrated in FIG. 7 and defined as the distance maximum measured between the first flow guide line 96 and the second flow guide line 99.

Preferably, the protuberances 9 each have chord lengths L _c of between 1 and 20 mm and / or maximum thicknesses e less than or equal to Le.

The protuberances 9 can have identical chord lengths L _c and / or maximum thicknesses e.

According to a variant, at least one protuberance 9 has a variation of at least one dimension chosen from its chord length L _c , its maximum thickness e, with respect to a respective dimension of at least one other protuberance 9 of the zone of distribution 3, 5. This offers an additional degree of freedom to best adjust the flow characteristics of the first fluid F1 according to the position of the guideline d _m in the distribution zone and / or according to the point of advance of the first fluid F1 along a direct line d _m .

In particular, the protuberances 9 of the same guideline d _m may have hydrodynamic profiles having chord lengths L _c increasing along at least one guideline d _m , and this from the interface 33 towards the interface link 43 in the case of an input distribution zone 3 or from the output interface 55 to the link interface 45 in the case of an output distribution zone. This change makes it possible to ensure good homogeneity of the distance between protuberances and of the quantity of material in the distribution zone.

Alternatively or in a complementary manner, the protuberances 9 of the same guideline d _m may have maximum thicknesses e which decrease in the direction of the connection interfaces 43, 45.

This change in the thicknesses and lengths of the protuberances 9 makes it possible to best adapt to the shape of the distribution zone considered.

These embodiments can be implemented on one or more guidelines.

According to an advantageous embodiment, the protuberances 9 have “airplane wing” hydrodynamic profiles of the “NACA” type. The use of NACA profiles in a distribution zone according to the invention offers the advantages of limiting the pressure drop in order to ensure good distribution while ensuring sufficient mechanical strength to withstand the conditions of use. In a hydrodynamic profile of the NACA type, the first flow guide line 96 forming a first so-called “upper surface” camber of the profile and the second flow guide line 99 forms a second so-called “lower surface” camber.

The hydrodynamic profile having a median camber 98 located at any point of its length at an equal distance from the upper surface 96 and the lower surface 99, said median arch 98 connecting one end 92a of the leading edge 92 and one end of the leading edge. leak 97 located on the guideline dm or having at least its ends 92a and 97a superimposed on the guideline.

Preferably, the protrusions 9 have hydrodynamic profiles of the non-symmetrical arched NACA type with a first arch 96 curved towards the outer contour D and a second arch curved towards the outer contour D. This makes it possible to guide the flow between the gradual entry and exit of the distribution area by limiting pressure drops. The first and second camber do not necessarily have the same degree of camber.

It being specified that the profile is preferably a NACA profile without a sharp edge, with a trailing edge 97 of rounded shape.

Fig. 7 shows an example of a protuberance 9 of NACA profile arranged in an outlet distribution zone 5. According to this example, the median camber 98 can be defined with respect to a guideline d _m of elliptical or parabolic shape separating two distribution channels from the distribution zone. A change of reference is made, to pass into the reference associated with the curvilinear abscissa (s) associated with the curve d _m between the leading edge 92 of the curvilinear abscissa so and the trailing edge 97 of abscissa s ^ .

We define the half-thickness y _t of the profile by the equation:

y _t = 5 * e \ 0.2969 - Q.1260x - 0.3516 x ² + 0.2843 x ³ - 0.1015 x ⁴ ]

- x is the normalized position between 0 and 1 on a line connecting the leading edge and the trailing edge,

- e is the maximum thickness of the NACA profile along the chord.

The median camber Y _c of the NACA profile can be calculated with the equation: or :

x is the normalized position between 0 and 1 on a line connecting the leading edge and the trailing edge.

K1, K2 and K3 digital parameters adjustable according to the desired camber profile.

cm the maximum arch.

For the shape of the upper and lower surfaces, the thickness should be applied perpendicular to the camber line, the coordinates (x _u , yu) and (XL, YL) can be calculated with the following equations: acp— x— jft siii QU ^ ÿc + Vt COS 0

xi x + ¾ sintf VL - Ve - Vt eosi

or :

According to one embodiment, the distribution zone 3, 5 comprises a plurality of guidelines d _m , d _{m + i} , d _{m +} 2 ... arranged homothetically to each other from a center of homothety O towards the external contour D, the center of homothety O being located at the intersection between the connection interface 43, 45 and the fluid inlet or outlet interface 33, 55. Such a zone is shown schematically in FIG. 6.

In the case where the distribution zone 3, 5 comprises a number M of distributor channels 31, 51, M being an integer greater than 1, said channels have, at the level of the fluid inlet or outlet interface 33, 55, first dimensions which are preferably substantially identical, and have, at the level of the connection interface 43, 45, second dimensions which are preferably substantially identical, said first and second dimensions being measured in the longitudinal x and lateral y direction respectively.

Advantageously, the distribution zone 3, 5 comprises a plurality of guidelines d _m , d _{m + i} , d _{m +} 2 ... each referenced by an index m, with m an integer ranging from 1 to M-1, each directing line d _m , d _{m + i} , d _m +2 being a homothetic curve of the external contour D with a homothety ratio k _m = m / M.

Preferably, the outer contour D defines an arc of a curve, preferably an arc of an ellipse or a parabola. In a coordinate system X, Y ordinate and origin (0; 0; 0) located at the intersection between the input or output interface 33, 55 and the link area 43, 45 ( see Fig. 5), the external contour D can be defined by a portion of an elliptical or parabolic curve. The outer contour can be defined respectively by the equations:

Z7 + ¾- = ¹ > and

They are therefore functions of the form Y = f (X, L _x , L _y ), with L _x the first length of the input or output interface and L _y the second length of the link interface.

Let us take a distribution area 3, 5 with a number M of distribution channels 31, 51, the channels being defined by M-1 guidelines. Each guideline is a curve defined by a function Y _m = f (X, L _xm , L _ym ), with L _xm = L _x ^* m / M and L _ym = L _y ^* m / M.

By identifying the channels 31 j, 31, + i, 31, + 2 _... (see Fig. 7) by an index i, with i an integer ranging from 1 to M, the channel of index i is defined between the two guidelines defined by the above function with m = i-1 and m = i.

Thus, for a 10-channel area and 9 guidelines, the 5 ^th channel from the center O of scaling is defined between the lines defined by the functions Y4 = f (X, L _X 4, L _y 4) and Y ₅ = f (X, L _X 5, L _y s), with L _X 4 = L _X ^* 4/10 and L _y4 = L _y ^* 4/10 and L _X5 = L _X ^* 5/10 and L _y5 = L _y ^* 5/10. According to one embodiment, the distance between two protuberances is adjusted in order to ensure good mechanical strength and to consider finishing steps (such as the deposition of a protective coating against corrosion, the deposition of a catalyst, ...), of the wall separating two successive floors. This distance may correspond to the width of an exchange channel, measured in the lateral direction y. Having the distance between protuberance and its neighboring protuberances greater than or equal to the diameter of the channels of the exchange zone makes it possible to ensure that the distribution zone is not the weak point for the flow of any fluid used. as part of a completion. Consequently, this distance helps to prevent any excessive deposit in the distribution area causing local clogging of the hydraulic passages. The fluids used for finishing can have physical properties very different from the fluid used during the operation of the exchanger-reactor or the exchanger. It is thus possible to use a notion of a circle inscribed between the protuberances, as illustrated in FIG. 10. The maximum diameter of this circle will preferably not be too large to limit the mechanical impact. It can be determined according to the operating pressure of the exchanger. Preferably, the maximum diameter of the inscribed circle will be 8 mm. Furthermore, this diameter will preferably be at least 2 mm in order to preserve a good flow of the fluid.

Heat exchange and mechanical strength can also be intensified by increasing the number of protrusions. In particular, a predetermined number of protuberances can be arranged along guidelines and additional protuberances staggered between these guidelines, as shown for example in FIG. 8.

Preferably, the connection interface 43, 45 and the fluid inlet or outlet interface 3a, 5a are dimensioned according to a ratio R = L _y / L _x of between 2 and 5.

The exchange zone 4 comprising an integer number N of exchange channels 41, N preferably being a multiple of the number M of distributor channels in order to be able to align, at the level of the link interface 43, 45, a sub- set of exchange channels 41 with a distributor channel. Two guidelines of indices m and m + 1 forming between them a distributor channel of index i = m then join two partitions 46 delimiting between them at least two exchange channels (see for example Fig. 8).

In particular, the distribution zone 3, 5 can comprise a number M of distribution channels 31, 51 with M = N / R with R an integer greater than or equal to 1 Advantageously, for each directing line, the protuberance 9 closest to the exchange zone is extended until it merges with a partition 46 delimiting two successive exchange channels and arranged opposite the protuberance 9.

Advantageously, the distribution zone 3, 5 comprises a number of protuberances A along the same guideline, A being defined as a function of the index m referencing the guideline, m being an integer ranging from 1 to M- 1, by the relation A = (m ² -1) / 4 if m is odd or A m = ^2/4 if m is even.

This relation makes it possible to maximize the number of protuberances in a minimum bulk. In addition, this ensures good distribution of the fluid by reducing the criterion defining the homogeneity of the distribution and which can be expressed by the ratio (Vmax - Vmin) A / _m o _y , with Vmax and Vmin the maximum speeds and minimum reached by the fluid at the level of the connection interface and V _m o _y the speed of the fluid at the level of the connection interface averaged over all of the distribution channels.

Preferably, the protuberances total an overall section S9 defined as the sum of the areas of the cross sections of each protuberance 9, measured in a plane parallel to the longitudinal direction x and parallel to the lateral direction y, with a ratio Sg / S _Di s _t n _b of at least 2%, preferably less than 30%, more preferably between 4 and 20%.

In use, with a first fluid F1 circulating in the distribution channels at a given pressure P, S9 is preferably determined so that:

With S _Di s _t ri _b the section of the distribution zone defined by the volume of the distribution zone divided by the thickness of the distribution zone and Omax _d miss the limit in terms of stress given by the code for l 'use of the material in which the distribution area is formed (ASME, EN13445, ...). Preferably, the pressure P applied in the distribution channels is between 1 barg and 40 barg (relative bar). For example, in the case of an Inconel 625 distribution area, subjected to maximum temperatures of 700 ° C and a pressure of 10 bar, taking safety factors of 0.7 for the material and 1.25 for creep with a service life of 100,000 hours, we have S9 / S _di stri _b = 15.5%

According to an advantageous embodiment, the distribution zone comprises at least one protuberance 9 connected, at the level of the connection interface, to a partition 46 delimiting an exchange channel 41, so that said protuberance is in contact, or even merges, that is to say forms the same part, with the partition 46 (see FIG. 8).

Preferably, each guideline has a protuberance 9 connected with a partition 46 of the exchange zone 4.

Advantageously, a second connecting fillet (14 in Fig. 8) is provided at the level of at least one junction between a protuberance 9 and a partition 46. The second fillet extends in a plane parallel to the longitudinal x and lateral directions. y and preferably over the entire height of the floor 10. The connection fillet can be provided on the side of the exchange zone 4 and / or on the side of the distribution zone 3, 5. The second connection fillet allows improve mechanical resistance by eliminating sharp angles.

Alternatively or in addition, a first fillet can be provided at the level of at least one junction between a protuberance 9 and a wall. Preferably, the first fillet extends over the entire periphery of the protuberance. The radii of curvature of the protuberances at the interfaces with the lower and upper walls of the floors help prevent concentrations of mechanical stress.

Preferably, said first and second fillets have radii of curvature r _c between 0.2 mm and the half-height h of stage 10. This dimensioning makes it possible to avoid stress concentrations. The fillets have concave profiles.

Preferably, the exchanger-reactor or the exchanger according to the invention is formed in one piece, or in other words of the monobloc type, that is to say having no assembly interface between the distribution zone. and the exchange zone and between the different floors of these zones.

Advantageously, at least the walls 12, the exchange channels 41, the distributor channels 31, 51, the protuberances 9 are formed integrally by an additive manufacturing process. The part is built layer by layer, the layers are of the order of 50 μm, depending on the precision of the desired shapes and the desired deposition rate. This type of process makes it possible to finely control the deposition of the material in the desired zones and makes it possible to produce three-dimensional parts of more complex shape than with conventional manufacturing methods.

Preferably, the additive manufacturing method uses at least one micrometric-sized metal powder as base material, and / or at least one laser as energy source.

The metal to be melted can be supplied either by powder bed or by a spray nozzle.

Preferably, a laser melting process on a bed of metal powder is used. Metallic powders of micrometric size are melted by one or more lasers. The lasers used to locally melt the powder are either YAG, fiber or CO2 lasers and the melting of the powders is carried out under inert gas, such as argon, helium, mixtures of argon and helium. .

In order to facilitate the additive manufacturing process, the protrusions 9 may each have, in section in a plane parallel to the longitudinal direction x and to the stacking direction z, a front edge 9a and a rear face 9b inclined at an angle Q with respect to the stacking direction z, preferably an angle Q of between 0 and 45 °. This embodiment is illustrated in FIG. 9. Tending to 45 ° improves additive manufacturability by printing the heat exchanger in the primary direction of fluid flow.

Advantageously, the exchanger-reactor according to the invention is of the millistructured, or even microstructured, type. In other words, the exchange channels of the millistructured exchanger are of millimeter dimensions, for example with a height h between the walls of the order of 0.2 mm to 10 mm and a width of the same order of magnitude. . Thus, the structuring and reduction of the fluid passage section in the channels allows the intensification of heat and mass transfers during the reaction.

Claims

1. Exchanger-reactor or exchanger comprising a plurality of walls (12) stacked in a stacking direction (z) which is orthogonal to a longitudinal direction (x) and to a lateral direction (y), so as to define at least between them a first series of stages (10) configured for the flow of a first fluid (F1) and a second series of stages (1 1) configured for the flow of a second fluid (F2) to be connected indirect heat exchange with the first fluid (F1), in which:

- each stage (10) of the first series is defined between a pair of adjacent walls (12), a pair of longitudinal edges (10a) parallel to the longitudinal direction (x) and a pair of side edges (10b) parallel to the lateral direction (Y),

- each stage (10) is divided, along the longitudinal direction (x), into at least one exchange zone (4) and at least one distribution zone (3, 5) arranged upstream and / or downstream of the exchange zone (4), with connection interfaces (43, 45) each arranged between the exchange zone (4) and said distribution zone (3, 5),

- said exchange zone (4) comprises a plurality of exchange channels (41) delimited by partitions (46) which extend continuously between the two link interfaces (43, 45), and

- said at least one distribution zone (3, 5) comprises a plurality of distributor channels (31, 51) which each connect a fluid inlet (33) and / or fluid outlet (55) interface arranged on a longitudinal edge (10a) of the stage (10) with a connecting interface (43, 45) so as to convey the first fluid (F1) respectively to the exchange channels (41) and / or from the channels of exchange (41),

characterized in that said at least one distribution zone (3, 5) has, in a plane parallel to the longitudinal (x) and lateral (y) directions, a surface distribution section Sdistrib delimited by a connecting interface (43, 45), a fluid inlet or outlet interface (33, 55) and an external contour (D) of curved shape,

each distributor channel (31, 51) being delimited by at least one guideline (dm) which extends between the fluid inlet and / or outlet interface (33, 55) and a link interface (43, 45) and which is a homothetic curve of the external contour (D) with a predetermined homothety ratio (k _m ), and

a plurality of protrusions (9) being disposed along each directing line (d _m ) and extending between the pair of adjacent walls (12), said protuberances (9) being adapted to change at least one direction of flow of the first fluid (F1) and each having, in section in a plane parallel to the longitudinal (x) and lateral (y) directions, a wing-shaped hydrodynamic profile delimited by a leading edge (92), said edge of attack (92) being arranged so as to face the first fluid (F1) when it flows into the distribution zone (3, 5), a trailing edge (97) arranged downstream of the leading edge ( 92) in the direction of flow of the first fluid (F1), a first flow guide line (96) and a second flow guide line (99) mutually connecting the leading edge (92) and the leading edge (97), at least one of said first and second guide lines (96, 99) being curved towards the outer profile (D).

2. Exchanger-reactor or exchanger according to claim 1, characterized in that the walls (12) extend substantially parallel to each other and parallel to a plane defined by the longitudinal direction (x) and the lateral direction (y).

3. Exchanger-reactor or heat exchanger according to one of claims 1 or 2, characterized in that the leading edge (92) and the trailing edge (97) has rounded shapes, preferably convex shapes.

4. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the first guide line (96) flow and the second guide line (99) flow are curved in the direction of the outer profile ( D).

5. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the leading edge (92) and the trailing edge (97) are connected by a segment (C) defining a maximum length of the hydrodynamic profile. said length of chord (U), said segment (C) connecting one end (92a) of the leading edge (92) and one end (97a) of the trailing edge (97) with said ends (92a, 97a) located on the guideline (d _m ).

6. Exchanger-reactor or exchanger according to claim 5, characterized in that the hydrodynamic profile has a chord length (U) between the length of the guideline (d _m ) divided by the number of protuberances on said guideline ( d _m ) and said length of the guideline (d _m ) divided by three times said number of protuberances and a maximum thickness (e) between 5% and 10% of the chord length (U), the maximum thickness ( e) being defined as the maximum distance measured between the first flow guide line (96) and the second flow guide line (99)

7. Exchanger-reactor or exchanger according to one of claims 5 or 6, characterized in that at least one protuberance (9) has a variation of at least one dimension chosen from its length of chord (U), its thickness. maximum (e), with respect to a respective dimension of at least one other protuberance (9) of the distribution zone (3, 5).

8. Exchanger-reactor or exchanger according to one of claims 5 to 7, characterized in that

- the protuberances (9) of the same guideline (d _m ) have hydrodynamic profiles having chord lengths (L _c ) increasing in the direction of the connection interface (43, 45), and / or

- the protuberances (9) have hydrodynamic profiles having maximum thicknesses (e) decreasing along at least one guideline (d _m ) towards the connection interface (43, 45).

9 Heat exchanger-reactor or heat exchanger according to one of the preceding claims, characterized in that the protuberances (9) have hydrodynamic profiles of the "airplane wing" type, preferably of the "NACA" type, the first guide line flow (96) forming a first so-called "upper surface" camber of said profile and the second flow guide line (99) forming a second so-called "lower surface" camber of said profile and the hydrodynamic profile having a median camber (98) located at any point of its length equidistant from the upper surface (96) and the lower surface (99), said median camber (98) connecting one end (92a) of the leading edge (92) and one end (97a ) of the trailing edge (97) located on the guideline (d _m ).

10. Exchanger-reactor or heat exchanger according to one of the preceding claims, characterized in that the protuberances (9) have hydrodynamic profiles of the non-symmetrical arched NACA type comprising a first convex camber and a second hollowed out camber, with the first curved camber. oriented towards the outer contour (D).

1 1. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the distribution zone (3, 5) comprises a plurality of guidelines (d _m , d _{m + i} , d _{m +} 2 ...) arranged homothetically to each other from a center of homothety (O) to the outer contour (D), the center of homothety (O) being located at the intersection between the link interface (43, 45) and the interface fluid inlet or outlet (33, 55).

12. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the distribution zone (3, 5) comprises a number M of distributor channels (31, 51), M being an integer greater than 1, said channels having, at the level of the fluid inlet or outlet interface (33, 55), first substantially identical dimensions, and having, at the level of the connection interface (43, 45), second dimensions substantially identical, said first and second dimensions being measured along the longitudinal (x) and lateral (y) direction respectively, the distribution zone (3, 5) comprising a plurality of guidelines (d _m , d _{m + i} , d _{m +} 2 ...) each referenced by an index m, m being an integer ranging from 1 to M-1, each direction line being a homothetic curve of the external contour (D) with a homothety ratio k _m = m / M.

13. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the outer contour (D) is elliptical or parabolic in shape.

14. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the connecting interface (43, 45) has a first length (L _y ) measured in the lateral direction (y) and the interface d 'fluid inlet or outlet (33, 55) has a second length (L _x ) measured along the longitudinal direction (x), the connection interface (43, 45) and the inlet or outlet interface of fluid (3a, 5a) being sized according to a ratio R = L _y / L _x ranging between 2 and 5, the exchange zone (4) comprising a number N of exchange channels (41) and the distribution zone (3, 5) comprising a number M of distributor channels (31, 51) with preferably M = N / R.

15. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the protuberances (9) totaling an overall section (S ₉ ) defined as the sum of the surfaces of the cross sections of each protuberance (9) measured in a plane. parallel to the longitudinal direction (x) and parallel to the lateral direction (y), with an S9 / S _Di s _t ri _b ratio of at least 2%, preferably less than 30%, more preferably between 4 and 20%.

16. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that there is provided a first connection fillet at at least one junction between a protuberance (9) and a wall (12) and / or a second fillet is provided at the level of at least one junction between a protuberance (9) and a partition (46) delimiting an exchange channel (41), said first and second fillet joints having radii of curvature between 0.2 mm and the half-height (h) of the floor (10), said height (h) being measured in a stacking direction (z) of the walls (12) which is orthogonal to the direction longitudinal (x) and lateral direction (y).

17. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that at least the walls (12), the exchange channels (41), the distributor channels (31, 51), the protuberances (9 ) are formed integrally by an additive manufacturing process, preferably a metal powder bed laser fusion process.

18. Exchanger-reactor or exchanger according to one of the preceding claims, characterized in that the protuberances (9) each having, in section in a plane parallel to the longitudinal direction (x) and to the stacking direction (z) , a front edge (9a) and a rear edge (9b) inclined at an angle (Q) with respect to the stacking direction (z), preferably an angle (Q) of between 5 and 40 °.