EP3228970A1 - Method for producing at least one plate heat exchanger by superimposing plates with alignment patterns - Google Patents

Abstract

The main object of the invention is a method for manufacturing at least one heat exchanger (50) with plates (10) for at least two fluid circuits, characterized in that it comprises the following steps: forming a plurality of plates (10) each having a reference pattern; b) forming one or more alignment patterns (11) on each plate (10) by circularly repeating the reference pattern about an axis of revolution (X); c) forming a plurality of grooves (12) on each plate (10). The method further comprises the following successive steps: d) assembling the plates (10) by superimposition relative to each other, each reference pattern of a plate being superimposed on an alignment pattern (11) of a plate adjacent; e) performing an assembly treatment on the assembly obtained at the end of the preceding step d) by soldering-diffusion, brazing and / or by diffusion-diffusion.

Description

TECHNICAL AREA

The present invention relates to the general field of plate heat exchangers, in particular plate heat exchangers with at least two fluid circuits each comprising one or more internal fluid circulation channels.

The invention also relates to the manufacture of such plate heat exchangers by diffusion welding, obtained by the technique of Hot Isostatic Compression (CIC), the technique of Uniaxial Hot Heat (CUC), and / or brazing.

Known heat exchangers typically include one or at least two internal fluid circulation channel circuits. In heat exchangers with a single fluid circuit, heat exchange takes place between the circuit and the environment in which it is immersed. In the exchangers with at least two fluid circuits, the heat exchanges are carried out between the different fluid circuits.

Furthermore, it is known chemical reactors which implement a continuous process in which a small amount of co-reactants is injected simultaneously, at the inlet of a first fluid circuit, preferably equipped with a mixer, the chemical product obtained being recovered at the outlet of said first circuit. Among these known chemical reactors, some include a second fluid circuit, usually called utility, whose function is to thermally control the chemical reaction, either by providing the heat necessary for the reaction, or on the contrary by removing the heat released by that -this. Such chemical exchangers with two fluid circuits with utility are usually called "reactor-exchangers".

It should thus be noted that the present invention relates both to the production of heat exchangers with a function solely of heat exchange, and to the production of reactor-exchangers. Also, by the expression "plate heat exchanger with at least two fluid circuits", it should be understood, in the context of the invention, as well a heat exchanger with only heat exchange function that a reactor-exchanger.

The invention thus proposes a method for manufacturing at least one plate heat exchanger with at least two fluid circuits by superposition of a plurality of plates each comprising alignment units, as well as a plate heat exchanger. at least two fluid circuits obtained by such a method.

STATE OF THE PRIOR ART

The so-called existing plate heat exchangers have significant advantages over the so-called existing tube heat exchangers, in particular their thermal performance and their compactness due to a favorable ratio of the surface area to the heat exchange volume.

The known tube exchangers are, for example, tube and shell exchangers, in which a bundle of upright or bent U-shaped or helical tubes is fixed on pierced plates and disposed inside a chamber called calender. In these tube and shell exchangers, one of the fluids circulates inside the tubes while the other fluid circulates inside the shell. These tube and shell exchangers have a large volume and are therefore of low compactness.

The known plate heat exchangers are more compact and are obtained by stacking plates comprising channels and assembled together.

The channels are made by stamping plates, where appropriate by adding strips folded in the form of fins, or by machining grooves. The machining is carried out by mechanical means, for example by milling or by chemical means. Chemical machining is usually called chemical or electrochemical etching.

The assembly of the plates together is intended to ensure the sealing and / or the mechanical strength of the exchangers, in particular the resistance to pressure of the fluids circulating inside.

Several assembly techniques are known and are implemented depending on the type of plate heat exchanger desired. The assembly can thus be obtained by mechanical means, such as tie rods holding the stack tight between two thick plates and rigid disposed at the ends. The sealing of the channels is then obtained by crushing reported joints. The assembly can also be obtained by welding, generally limited to the periphery of the plates, which sometimes requires to insert, after welding, the heat exchanger in a calender to allow it to withstand the pressure of the fluids. The assembly can still be obtained by brazing, in particular for exchangers for which fins are added. The assembly can finally be obtained by diffusion welding (welding-diffusion).

The last two techniques mentioned make it possible to produce exchangers that are particularly efficient in terms of mechanical strength. Indeed, thanks to these two techniques, the assembly is obtained not only at the periphery of the plates but also inside the exchanger.

Plate heat exchangers assembled by diffusion welding have joints that are even more mechanically efficient than the joints of the brazed exchangers due to the absence of the solder required for brazing.

Welding-diffusion consists of obtaining a solid state assembly by applying a hot force to the parts to be assembled during a given time. The applied force has a double function: it allows the docking, that is to say the contacting of the surfaces to be welded, and it facilitates the creep-diffusion elimination of the residual porosity in the joints (interfaces) .

The force can be applied by uniaxial compression, for example using a press equipped with an oven or simply using masses arranged at the top of the stack of parts to be assembled. This process is commonly known as uniaxial diffusion welding and is applied industrially for the manufacture of plate heat exchangers.

An important limitation of the uniaxial welding-diffusion process is that it does not allow any orientation joints to be welded with respect to the direction of application of the uniaxial compression force.

Another alternative method overcomes this disadvantage. In this other method, the force is applied via a gas under pressure in a sealed enclosure. This process is commonly referred to as Hot Isostatic Compression (CIC). Another advantage of the CIC welding-diffusion process compared to the uniaxial diffusion-diffusion process is that it is more widely used on an industrial scale. Indeed, the CIC is also used for the batch processing of castings as well as for the compaction of powders.

The currently known compact exchangers also have major disadvantages, mainly in the case of plate heat exchangers.

A first major drawback is the manufacturing cost of the plates, in particular in the case of engraved groove plates. In this case, the material is removed over a certain width and a certain depth in a particular direction in order to produce grooves which form the channels once the stack is made. The etching of the grooves can be performed one by one, batch or integrally according to the technique used and this etching can be performed on one or both sides of the plates of the exchanger.

The engraving of the grooves made by conventional mechanical machining makes it possible to obtain good dimensional tolerances, but this requires a very high cost, depending on the quality required. The chemical engraving certainly allows a certain reduction of cost compared to the previous case but which is quite relative. Indeed, relative to a given length, the cost of a channel of a plate heat exchanger made by chemical etching is greater than that of a tube exchanger.

Several technical solutions make it possible to manufacture compact heat exchangers consisting of plates by using different techniques such as brazing, as described, for example, in the international application WO 2008/087526 A2 , or welding diffusion, as described for example in the document titled "Fusion reactor first wall manufacturing techniques", G. Le Marois et al, Fusion Engineering and Design pages 61-62 (2002) 103-110 Elsevier Science BV or the international application WO 2006/067349 A1 . However, these techniques are laborious, expensive and difficult to implement in the majority of cases.

Another major disadvantage of compact heat exchangers diffusion welded plates is the lack of versatility of the elements constituting them. Indeed, the engraving of the grooves on one or both sides of the plates imposes the geometry of the channels with very little possibility of modification during assembly. Thus, a given groove design strongly conditions the geometry of the fluid circuits of the exchanger. The only possibility to modify this geometry (channel length, lateral dimensions, etc.) is to manufacture other plates, which generally represents an additional cost in design (CAD), validation tests, control.

Most of the inventions listed to date for compact heat exchangers made from plates do not clearly expose the means used to align the plates with each other.

For the exchangers using parallelepipedic plates, the latter are often adjusted relative to each other by using the admission and / or fluid extraction pipes, as described for example in the international applications WO 2005/073658 A1 and WO 01/07857 A1 . In rare cases, the inventions give some indications of pattern systems around the rectangular plates to align the fluid circuits with each other, as for example in international applications. WO 98/55812 A1 and WO 2013/43263 A1 , or in the US patent US 6,511,759 B1 .

For exchangers having a cylindrical final shape, in which the plates are discs, the latter are aligned either by a central hole, as described for example in the German patent application. DE 100 31 347 A1 or by a cylindrical container placed around the exchanger, as described for example in the US patent US 5,298,337 A . Patterns are sometimes made beforehand in the plates. The latter are used, in the majority of the cases, to fixings a posteriori of the manufacture of the exchanger without an explicit role is attributed to them as regards the alignment of the plates between them, as described for example in international demand WO 2008/087526 A2 .

STATEMENT OF THE INVENTION

The object of the invention is therefore to at least partially remedy the aforementioned needs and drawbacks relating to the embodiments of the prior art, and in particular to those inherent in processes for manufacturing heat exchangers with at least two fluid circuits mentioned previously.

1. a) formation d'une pluralité de plaques constitutives de l'échangeur de chaleur, chaque plaque comportant un motif creusé appelé « motif de référence »,
2. b) formation d'un ou plusieurs motifs creusés, comprenant le motif de référence, appelés « motifs d'alignement » sur chaque plaque par répétition circulaire du motif de référence autour d'un axe de révolution de la plaque, les axes de révolution des plaques étant confondus,
3. c) formation d'une pluralité de rainures, destinées à former les canaux de circulation des fluides de l'échangeur à plaques, sur chaque plaque, les rainures comprenant au moins une première pluralité de rainures pour le premier circuit de fluide et une deuxième pluralité de rainures pour le deuxième circuit de fluide,

et en ce qu'il comporte en outre les étapes successives suivantes :

• d) assemblage des plaques par superposition les unes par rapport aux autres, chaque motif de référence d'une première plaque étant superposé à un motif d'alignement d'une deuxième plaque adjacente à la première plaque,
• e) réalisation d'un traitement d'assemblage sur l'assemblage obtenu à l'issue de l'étape d) précédente par soudage-diffusion, par brasage et/ou par brasage-diffusion.

The invention thus has, according to one of its aspects, a method of manufacturing at least one plate heat exchanger with at least two fluid circuits, characterized in that it comprises the following steps:

1. a) forming a plurality of plates constituting the heat exchanger, each plate having a hollow pattern called "reference pattern",
2. b) forming one or more hollow patterns, comprising the reference pattern, called "alignment patterns" on each plate by circular repetition of the reference pattern about an axis of revolution of the plate, the axes of revolution of the plates being merged,
3. c) forming a plurality of grooves for forming fluid circulation channels of the plate heat exchanger on each plate, the grooves including at least a first plurality of grooves for the first fluid circuit and a second plurality grooves for the second fluid circuit,

and in that it further comprises the following successive steps:

• d) superimposing the plates relative to each other, each reference pattern of a first plate being superimposed on an alignment pattern of a second plate adjacent to the first plate,
• e) performing an assembly treatment on the assembly obtained at the end of the preceding step d) by soldering-diffusion, brazing and / or soldering-diffusion.

By "soldering-diffusion" is meant the usual definition for the person skilled in the art, as explained in the article "Assemblage by diffusion (welding or soldering)", Yves BIENVENU, Techniques of the Engineer, Reference BM 7747, October 10, 2010 .

Moreover, by the expression "dug pattern", it should be understood that the pattern may have a hollow shape, passing through or not, or even partially through, for example an opening or a stamped form. The hollow pattern can thus be obtained by various techniques, in particular such as by a process of deformation of the material without removal of material, such as stamping, and / or by a method of producing the pattern by removal of material, such as machining, laser cutting, photochemical etching, etc.

Thanks to the invention, it is possible to obtain several significant advantages over traditional plate heat exchangers with at least two fluid circuits. The invention makes it possible both to significantly reduce the manufacturing costs of the heat exchangers and to make more versatile plate geometry constituting these exchangers or a set of plates with different designs. Indeed, the principle of "alignment patterns" makes it possible to realize different configurations of heat exchangers, that is to say of lengths and complete drawings of the different fluid circuits, by using the same sets of plates, realized thanks to the invention. The cost is thus reduced because the "generic" plates can be made in large quantities and a simple modification of the method of mounting the plates on top of one another can change the morphology of the fluid channels significantly.

The manufacturing method according to the invention may further comprise one or more of the following characteristics taken separately or in any possible technical combinations.

The reference pattern may or may not be traversing. Similarly, the alignment pattern (s), including the reference pattern, may or may not be traversing.

The axes of revolution of the plates advantageously take advantage each as a center of rotation a virtual point located on the surface of the plate considered, called "center of rotation", and as axis of rotation normal to said plate passing through the center of rotation. The axis of revolution of a plate can in particular correspond to its central axis of symmetry.

Advantageously still, the distance between the center of each alignment pattern, including the reference pattern, and the center of rotation of the plate bearing these alignment patterns is the same for all plates of the heat exchanger.

Advantageously also, the alignment patterns allow indexing of the plates relative to each other.

The grooves, intended for the circulation of the fluids, may or may not be through. In particular, they can be made by non-through etching and / or through-hole cutting. The grooves may or may not be made by circular repetition of a repetition angle different or not the repetition angle of the alignment patterns around the axes of revolution of the plates.

In addition, the realization of the grooves can be carried out simultaneously with or independently of the embodiment of the alignment patterns, comprising the reference pattern, on each plate.

Moreover, the constituent plates of the heat exchanger may comprise identical or different groove designs for all the plates.

The plates may or may not have the same transverse dimensions and / or the same thickness.

The alignment patterns, including the reference pattern, may for example have a cross section of circular or polygonal shape, for example triangular, square, rectangular, pentagonal, hexagonal, among others.

1. i) disposer une première plaque sur un support,
2. ii) superposer une deuxième plaque à la première plaque en faisant coïncider le motif de référence de la deuxième plaque avec un motif d'alignement de la première plaque,
3. iii) placer un outillage d'alignement au niveau des motifs coïncidant formés par le motif de référence de la deuxième plaque et le motif d'alignement de la première plaque, l'outillage d'alignement permettant de maintenir la coïncidence desdits motifs,
4. iv) éventuellement, placer un autre outillage d'alignement au niveau de deux autres motifs coïncidant formés par un motif d'alignement de la première plaque et un motif d'alignement de la deuxième plaque, superposés entre eux et différents des motifs utilisés à l'étape ii),
5. v) superposer N plaques, N étant un nombre entier supérieur ou égal à 1, à la deuxième plaque, chaque N^ième plaque étant superposée par coïncidence de son motif référence à un motif d'alignement de la plaque avec laquelle elle est superposée selon le principe de l'étape ii), et par utilisation d'au moins un outillage d'alignement selon le principe de l'étape iii).

Furthermore, step d) of assembling the plates can comprise the following successive sub-steps:

1. i) arranging a first plate on a support,
2. ii) superimposing a second plate on the first plate by aligning the reference pattern of the second plate with an alignment pattern of the first plate,
3. iii) placing an alignment tool at the coincident patterns formed by the reference pattern of the second plate and the alignment pattern of the first plate, the alignment tooling for maintaining the coincidence of said patterns,
4. iv) optionally, placing another alignment tool at two other coincident patterns formed by an alignment pattern of the first plate and a pattern of alignment of the second plate, superimposed between them and different from the patterns used in step ii),
5. v) superimposing N plates, N being an integer greater than or equal to 1, to the second plate, each ^Nth plate being superimposed by coincidence of its pattern refers to an alignment pattern of the plate with which it is superimposed according to the principle of step ii), and using at least one alignment tool according to the principle of step iii).

In step ii) above, the reference pattern of the second plate may be superimposed with an alignment pattern of the first plate which may be either the reference pattern of the first plate or another motif of the first plate. different alignment of the reference pattern. Advantageously, the superposition is performed so as to allow the circulation of said at least two fluids from the channels of the first plate to the channels of the second plate.

After positioning the alignment tool at the coinciding patterns, it is advantageous to obtain axes of revolution of the first plate and the second plate which are collinear. Also, in order to facilitate the mounting of the plates together and to obtain this collinearity of the axes of revolution, it is preferable to implement step iv) using at least two alignment tools.

During step ii) or step v), especially in the case of the use of plates of identical geometry, it may be possible to make the top face of the N ^th plate coincide with the underside. of the (N + 1) ^th plate or to make the top face of the N ^th plate coincide with the top face of the (N + 1) ^th plate, by turning the (N + 1) ^th plate. This may depend on the channel geometry of the plates of the heat exchanger and / or the desired final geometry of the channels.

The alignment tool or tools may have a transverse dimension, in particular a diameter, substantially equal to the transverse dimension, in particular the diameter, of alignment patterns of the plates.

The alignment tool or tools may in particular have a cross section similar in shape to that of the alignment patterns, for example circular or polygonal.

The length of an alignment tool is advantageously greater than or equal to the total length of the plates assembled together, namely at the end of step d).

Advantageously, the alignment tool or tools have a suitable shape to allow at least two plates to be aligned with each other. The alignment tool or tools may in particular have a cylindrical shape.

Step e) of carrying out an assembly treatment may comprise diffusion-bonding and / or soldering-diffusion, in particular by the hot isostatic pressing (CIC) technique and / or by the uniaxial compression technique. hot (CUC).

As a variant, the step e) of carrying out an assembly treatment may comprise brazing.

In addition, the angle of the circular repetition, called "angle of rotation", of the reference pattern of each plate around the considered axis of revolution of the plate can be identical for all the plates.

As a variant, the angle of the circular repetition, called the "angle of rotation", of the reference pattern of each plate around the considered axis of revolution of the plate may be different for at least two of the plates, in particular all of the plates. plates. In this case, the value of each rotation angle of the reference pattern to form one or more alignment patterns is advantageously an integer multiple of the smallest rotation angle value among all the rotational angles forming the alignment patterns.

• f) fabrication d'un échangeur de chaleur à plaques par combinaison des modules élémentaires d'échangeur de chaleur à plaques entre eux.

Furthermore, the method can be implemented for the manufacture of a plurality of elementary modules of plate heat exchanger, each elementary module of plate heat exchanger being obtained by means of steps a) to e) , and the method may then comprise the following step:

• f) manufacturing a plate heat exchanger by combining the elementary heat exchanger modules with plates.

The elementary modules intended to be combined with each other to form a larger heat exchanger may be identical or different from each other. others, for example by alternating different plates. The elementary modules can also be combined in series or in parallel by connecting the channels of one module to the channels of another module. The tightness to finalize the assembly of the plate heat exchanger thus formed can be achieved by soldering-diffusion, brazing and / or soldering-diffusion, or even by more conventional welding techniques such as welding laser or TIG welding or by adding crushed joints by mechanical clamping.

The realization of elementary modules has the advantage of being able to manufacture and store elementary modules, and then to be able to make custom heat exchangers according to the requirements demanded on these heat exchangers.

In addition, the plates can all have an identical shape. Alternatively, the plates may have different shapes.

The shapes of the plates can be of different types, for example circular or polygonal, for example triangular, square, rectangular, pentagonal, hexagonal, among others.

The plates can be made of metal, especially stainless steel.

In addition, each plate may comprise a registration element to make it possible to know the position of said at least one reference pattern of the plate.

The registration element may be in the form of a notch made at the periphery of the plate.

Furthermore, the invention further relates, in another of its aspects, a plate heat exchanger to at least two fluid circuits, characterized in that it can be obtained by means of the method as defined above.

The manufacturing method and the plate heat exchanger according to the invention may comprise any of the features set forth in the description, taken alone or in any technically possible combination with other characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 représente une vue isométrique d'un exemple de plaque métallique circulaire d'un échangeur de chaleur à plaques à deux circuits de fluide conforme à un premier mode de réalisation de l'invention,
• la figure 1A est une vue de détails selon A de la plaque de la figure 1,
• les figures 1B et 1C sont des vues de détails selon B' de la plaque de la figure 1 vue de dessus, différemment référencées,
• la figure 2 représente, schématiquement en perspective, un exemple d'outillage d'alignement de l'échangeur de chaleur à plaques conforme au premier mode de réalisation de l'invention, constitué d'une pluralité de plaques selon la figure 1,
• la figure 3 représente une vue en négatif des motifs d'alignement de la plaque de la figure 1, ainsi que d'une rangée de rainures du premier fluide et d'une rangée de rainures du deuxième fluide,
• les figures 4A et 4B représentent, partiellement en perspective, un cas d'échangeur de chaleur conforme au premier mode de réalisation de l'invention dans lequel le motif de référence d'une plaque supérieure est aligné avec celui de la plaque inférieure, l'axe de rotation de la plaque supérieure étant également aligné avec l'axe de rotation de la plaque inférieure, la figure 4B permettant de visualiser en transparence partielle la plaque inférieure,
• la figure 5 représente une vue en négatif, semblable à celle de la figure 3, illustrant la configuration des figures 4A et 4B,
• la figure 5A est une vue de l'assemblage de la figure 5 suivant le plan C',
• les figures 6A et 6B représentent, partiellement en perspective, un cas d'échangeur de chaleur conforme au premier mode de réalisation de l'invention dans lequel le motif de référence d'une plaque supérieure est décalé à droite (rotation horaire d'un pas) du motif de référence de la plaque inférieure, l'axe de rotation de la plaque supérieure étant aligné avec l'axe de rotation de la plaque inférieure, la figure 5B permettant de visualiser en transparence partielle la plaque inférieure,
• la figure 7 représente une vue en négatif, semblable à celle de la figure 3, illustrant la configuration des figures 5A et 5B,
• la figure 7A est une vue de l'assemblage de la figure 7 suivant le plan D,
• la figure 8 représente une vue en négatif, semblable à celle de la figure 3, dans le cas d'un échangeur de chaleur conforme au premier mode de réalisation de l'invention dans lequel on effectue un décalage des motifs de référence lors de l'empilement des plaques en effectuant trois rotations horaires d'un pas, puis trois rotations antihoraires d'un pas, le tout sur 21 plaques, les axes de rotation de l'ensemble des plaques étant tous colinéaires,
• la figure 8A est une vue de l'assemblage de la figure 8 suivant le plan E,
• la figure 9 représente une vue isométrique d'un exemple de première plaque métallique hexagonale d'un échangeur de chaleur à plaques à deux circuits de fluide conforme à un deuxième mode de réalisation de l'invention,
• la figure 9A est une vue partielle de dessus de la figure 9,
• la figure 9B est une vue rapprochée du centre de la figure 9,
• la figure 10 représente une vue isométrique d'une deuxième plaque intermédiaire de l'échangeur de chaleur à plaques conforme au deuxième mode de réalisation de l'invention, permettant de faire la liaison entre deux plaques du type de celle présentée sur la figure 9,
• la figure 10A est une vue partielle de dessus de la figure 10,
• la figure 11 représente une vue isométrique d'une troisième plaque de l'échangeur de chaleur à plaques conforme au deuxième mode de réalisation de l'invention, permettant de former une première plaque de fermeture,
• la figure 12 représente une vue isométrique d'une quatrième plaque de l'échangeur de chaleur à plaques conforme au deuxième mode de réalisation de l'invention, permettant de former une deuxième plaque de fermeture,
• la figure 13 représente, schématiquement en perspective, un exemple d'outillage d'alignement de l'échangeur de chaleur à plaques conforme au deuxième mode de réalisation de l'invention, constitué des plaques des figures 9, 10, 11 et 12,
• la figure 14 représente une vue éclatée d'un échangeur de chaleur conforme au deuxième mode de réalisation de l'invention, ou un module élémentaire d'un échangeur de chaleur conforme au deuxième mode de réalisation de l'invention, constitué des plaques des figures 9, 10, 11 et 12,
• la figure 14A représente l'empilement de la figure 14 selon une vue assemblée, montrant l'orientation des plaques les unes par rapport aux autres,
• la figure 15 représente l'échangeur de chaleur conforme au deuxième mode de réalisation de l'invention, ou le module élémentaire d'un échangeur de chaleur conforme au deuxième mode de réalisation de l'invention, de la figure 14, après les étapes de fabrication et d'usinage finales,
• la figure 16 représente une vue en négatif des motifs d'alignement et rainures de la figure 9,
• la figure 17 représente la superposition de deux plaques de la figure 9, l'une étant inversée par rapport à l'autre, vues en négatif, et
• la figure 17A représente une vue en négatif de l'empilement de la figure 17 avec la plaque de la figure 10.

The invention will be better understood on reading the following detailed description of examples of non-limiting implementation thereof, as well as on examining the schematic and partial figures of the appended drawing. on which :

• the figure 1 is an isometric view of an exemplary circular metal plate of a two fluid circuit plate heat exchanger according to a first embodiment of the invention,
• the Figure 1A is a detail view according to A of the plate of the figure 1 ,
• the Figures 1B and 1 C are detailed views according to B 'of the plate of the figure 1 top view, differently referenced,
• the figure 2 represents, schematically in perspective, an example of alignment tooling of the plate heat exchanger according to the first embodiment of the invention, consisting of a plurality of plates according to the figure 1 ,
• the figure 3 represents a negative view of the alignment patterns of the plate of the figure 1 , as well as a row of grooves of the first fluid and a row of grooves of the second fluid,
• the Figures 4A and 4B show, partially in perspective, a case of heat exchanger according to the first embodiment of the invention in which the reference pattern of an upper plate is aligned with that of the lower plate, the axis of rotation of the upper plate is also aligned with the axis of rotation of the lower plate, the Figure 4B allowing to visualize in partial transparency the lower plate,
• the figure 5 represents a negative view, similar to that of the figure 3 , illustrating the configuration of Figures 4A and 4B ,
• the Figure 5A is a view of the assembly of the figure 5 according to plan C ',
• the Figures 6A and 6B represent, partially in perspective, a case of heat exchanger according to the first embodiment of the invention in which the reference pattern of an upper plate is shifted to the right (clockwise rotation of a step) of the reference pattern the bottom plate, the axis of rotation of the plate being aligned with the axis of rotation of the lower plate, the Figure 5B allowing to visualize in partial transparency the lower plate,
• the figure 7 represents a negative view, similar to that of the figure 3 , illustrating the configuration of Figures 5A and 5B ,
• the Figure 7A is a view of the assembly of the figure 7 according to plan D,
• the figure 8 represents a negative view, similar to that of the figure 3 , in the case of a heat exchanger according to the first embodiment of the invention in which the reference patterns are shifted during the stacking of the plates by making three hourly rotations of one step, then three rotations. anti-clockwise, all on 21 plates, the axes of rotation of all the plates being all collinear,
• the figure 8A is a view of the assembly of the figure 8 according to plan E,
• the figure 9 is an isometric view of an example of a first hexagonal metal plate of a two fluid circuit plate heat exchanger according to a second embodiment of the invention,
• the Figure 9A is a partial view from above of the figure 9 ,
• the Figure 9B is a close-up view of the center of the figure 9 ,
• the figure 10 represents an isometric view of a second intermediate plate of the plate heat exchanger according to the second embodiment of the invention, making it possible to link two plates of the type shown on the figure 9 ,
• the figure 10A is a partial view from above of the figure 10 ,
• the figure 11 represents an isometric view of a third plate of the plate heat exchanger according to the second embodiment of the invention, for forming a first closure plate,
• the figure 12 is an isometric view of a fourth plate of the plate heat exchanger according to the second embodiment of the invention, for forming a second closure plate,
• the figure 13 represents, schematically in perspective, an exemplary alignment tooling of the plate heat exchanger according to the second embodiment of the invention, consisting of the plates of figures 9 , 10 , 11 and 12 ,
• the figure 14 represents an exploded view of a heat exchanger according to the second embodiment of the invention, or an elementary module of a heat exchanger according to the second embodiment of the invention, consisting of the plates of the figures 9 , 10 , 11 and 12 ,
• the figure 14A represents the stacking of the figure 14 according to an assembled view, showing the orientation of the plates relative to each other,
• the figure 15 represents the heat exchanger according to the second embodiment of the invention, or the elementary module of a heat exchanger according to the second embodiment of the invention, the figure 14 , after the final manufacturing and machining steps,
• the figure 16 represents a negative view of the alignment patterns and grooves of the figure 9 ,
• the figure 17 represents the superposition of two plates of the figure 9 , one being inverted with respect to the other, seen in negative, and
• the Figure 17A represents a negative view of the stack of the figure 17 with the plate of the figure 10 .

In all of these figures, identical references may designate identical or similar elements.

In addition, the different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS Example 1

With reference to Figures 1-8A a first embodiment of a plate heat exchanger 50 comprising two fluid circuits C1 and C2, consisting respectively of 130 channels and 150 channels, will be described below.

In this first embodiment of the invention, the method of manufacturing the heat exchanger 50 uses an assembly of a plurality of plates 10, such as that shown in FIG. figure 1 by diffusion bonding obtained by the Hot Isostatic Compression (CIC) technique.

In this example, the heat exchanger 50 has a plurality of plates 10 all identical and similar to that shown in FIG. figure 1 .

Thus, the plate 10, shown on the figure 1 , has a disc shape of diameter d1 and thickness e1. It comprises, on its periphery, a plurality of alignment patterns 11, in this case 130 alignment patterns 11 including the reference pattern 11a, and a plurality of grooves 12 between these alignment patterns 11 and 1. central axis of revolution X.

The Figure 1A is a detail view according to A of the plate 10 of the figure 1 , making it possible to better visualize the alignment patterns 11 of the plate 10.

Thus, each alignment pattern 11 has a disc shape passing through the plate 10 and having a diameter d2.

In order to be able to locate the reference pattern 11a with respect to the other alignment patterns 11 of the plate 10, a notch 13, forming a registration element 13, has been made at the periphery of the plate 10 at the reference pattern 11a.

Moreover, Figures 1B and 1 C are detailed views according to B 'of the plate 10 of the figure 1 top view.

The Figure 1B Thus, the grooves 121 of the fluid C1 and the grooves 122 of the fluid C2 appear. With respect to the center O of the plate 10, located on the central axis of revolution X, the first ring of grooves 121 of the fluid C1 begins at a distance r'1 from the center O and ends at a distance r'2 from the center O, so that the thickness of this first ring is equal to r'2 - r'1. The first ring of grooves 122 of the fluid C2 begins at a distance r'3 from the center O and ends at a distance r'4 from the center O, so that the thickness of this first ring is equal to r ' 4- r'3.

Thus, the separation between the first ring of grooves 121 of the fluid C1 and the first ring of grooves 122 of the fluid C2 is equal to r'1 - r'4. So the grooves following 121 and 122 fluids C1 and C2 are arranged in successive concentric rings.

It should thus be noted that, in this first embodiment of the invention, the grooves 12, including the grooves 121 and 122, are ring pieces having two opposite edges in an arc whose center is the center O of the plate 10, the two other opposite edges being straight and aligned along a radius of the plate 10. The alignment patterns 11 are located on a circle of center O and radius R3, as shown in FIG. Figure 1B .

In addition, the figure 1C represents the angles θ1, θ2, θ2 'and θ3 of the circular repetitions of the alignment patterns 11 and the grooves 12.

Thus, starting from the center O of the plate 10, the grooves 121 of the fluid C1 are repeated with an angle θ1 and the grooves 122 of the fluid C2 are repeated with an angle θ2 + θ2 '. As for the alignment patterns 11, they are repeated with an angle θ3.

The figure 2 For its part, it shows schematically in perspective an exemplary alignment tooling 20 of the plate heat exchanger 50 according to the first embodiment of the invention.

Thus, in order to allow the plates 10 to be aligned with each other, a plurality of alignment tools 20 are used, each being in the form of a cylindrical rod 20 of nominal diameter d2 equal to that of the alignment patterns 11 and of length L1, as visible on the figure 2 .

By way of nonlimiting examples, each plate 10 may be made of metal, in particular stainless steel, for example of the X2CrNiMo17-12-02 1.4404 type according to the European standard EN 10027, with a thickness e1 of the order of 0.5. mm for a diameter d1 of the order of 100 mm.

The alignment patterns 11 and / or the grooves 12 may be made by laser cutting and, unless otherwise indicated, the tolerances on the final dimensions may be of the order of ± 0.05 mm. In addition, the alignment patterns 11, here 130 in number, may have a diameter d2 of the order of 2 mm, being distributed over a circle of diameter equal to about 96 mm, the angle θ3 being equal to 360/130) °.

Furthermore, for the first ring of grooves 122 of the fluid C2, the distances r'3 and r'4 may respectively be equal to about 5 mm and 8 mm, ie a thickness of about 3 mm. The five rings of grooves 122 of the fluid C2 advantageously all have a thickness of about 3 mm.

In addition, for the first ring of grooves 121 of the fluid C1, the distances r'1 and r'2 may respectively be equal to about 9 mm and 13 mm, a thickness of about 4 mm. The four rings of grooves 121 of the fluid C1 advantageously all have a thickness of about 4 mm.

In addition, the separation between a ring of grooves 121 of the fluid C1 and a ring of grooves 122 of the fluid C2 is preferably identical for the entire plate 10, ie r'1 - r'4 = 1 mm. The values of the repetition angles can then be such that ½ * θ1 = θ2 = θ2 '= 6 °.

In order to better visualize the stacks, the latter will then be represented with diagrams of the plates 10 seen in "negative", that is to say that the grooves 12 and the alignment patterns 11 appear in thickness whereas the rest is empty.

Thus, by way of illustration, the figure 3 represents a negative view of the alignment patterns 11, forming channels 11 ', of the figure 1 with a row of grooves 121 of the fluid C1, forming channels 121 ', and a row of grooves 122 of the fluid C2, forming channels 122', having the geometric characteristics described above.

It will then be presented below, with reference to Figures 4A to 8 different sub-examples of assembly of the plates 10 according to the manufacturing method of the invention, to obtain various configurations of heat exchangers 50.

It is considered that each heat exchanger 50 obtained is formed by the assembly of 21 identical plates superimposed on each other, with the geometric characteristics described above. Thus, the total length L of these heat exchangers 50 after manufacture is about 10.5 mm.

In the first sub-example described with reference to Figures 4A to 5A , all of the reference patterns 11a of the plates 10 which constitute the stack forming the heat exchanger 50 are aligned with each other. The Figures 4A and 4B allow to visualize this first sub-example where only the superposition of two plates 10 is shown for the sake of clarity.

Then, once the stack is complete, the channels 11a 'formed by the reference patterns 11a are all aligned, as shown in FIG. Figure 5A , and therefore, the channels 121 'of the fluid C1 and the channels 122' of the fluid C2 respectively formed by stacking the grooves 121 and 122 are all vertically oriented, as illustrated by FIG. figure 5 .

In the second sub-example described now with reference to Figures 6A to 7A , all of the reference patterns 11a of the plates 10 which constitute the stack forming the heat exchanger 50 are offset by an angle θ3 in the clockwise direction (lower plate compared to that located above in the assembly ). The Figures 6A and 6B allow to visualize this second sub-example where only the superposition of two plates 10 is shown for the sake of clarity.

Then, once the stack is complete, the channels 121 'and 122' formed by the grooves 121 of the fluid C1 and 122 of the fluid C2 form stair steps in the same direction of rotation, as shown in FIG. figure 7 . By then observing the stacking according to the plane D, as according to the Figure 7A , the channel 11a 'formed by the reference pattern 11a of a plate 10 is found superimposed with the channels 11' of the alignment patterns 11 of all the plates 10 of the assembly but shifted by an angle step θ3 relative to the upper and / or lower plate.

In the third sub-example described now with reference to figures 8 and 8A , as for the second sub-example, the plates 10 are stacked with an offset of the reference patterns 11a according to a repeated sequence of the type θ3, θ3, -θ3, -θ3, etc. This alternation of offsets clockwise and counterclockwise makes it possible to obtain a stack of 21 plates 10 as represented on the figures 8 and 8A , with views respectively similar to those of Figures 7 and 7A .

It should be noted that the three subexamples described above are presented for illustrative and non-limiting purposes of the invention. The stacking combinations of the plates 10 to obtain heat exchangers 50, and the number of these plates 10, make it possible to achieve a very large number of different assemblies. In particular, it is found that the characteristics of the channels that can be obtained with only one type of plate 10 are very varied. In the three subexamples described, the channel lengths are different as are the passage sections. The channels can be given a geometric complexity capable of improving the efficiency of heat exchange by providing turbulence. This geometric complexity may also be of interest for the mixture in the case of reactor-exchangers previously described.

Example 2

Referring now to Figures 9 to 17A a second embodiment of a plate heat exchanger 50 comprising two fluid circuits C1 and C2, each consisting of a single channel, will be described below.

In this second embodiment of the invention, the method of manufacturing the heat exchanger 50 uses an assembly of a plurality of plates 10a, 10a ', 10b, 10c, 10d by diffusion welding obtained by the Hot Uniaxial Compression technique (CUC).

In this second example, unlike the first example described previously, the heat exchanger 50 comprises plates 10a, 10a ', 10b, 10c and 10d having different patterns. More specifically, the heat exchanger 50 comprises four types of plates.

The figure 9 represents the first plate model 10a of the heat exchanger 50.

Thus, the plate 10a, shown on the figure 9 , has a hexagonal shape, a thickness e2 and a width L2, corresponding to the distance between two opposite sides. The plate 10a has six alignment patterns 11 near each corner, including the reference pattern 11a. the reference pattern 11a is marked by means of a polarizer 13, forming a registration element 13. Moreover, a plurality of grooves 12 is formed on the plate 10a around the central axis of revolution X. These grooves 12 include grooves 121 for the fluid C1 and grooves 122 for the fluid C2.

The Figure 9A has a view from above of half of the plate 10a of the figure 9 . On this Figure 9A it can be seen that the polarizer 13 is in the form of a diamond-shaped notch 13 in the corner bearing the reference pattern 11a. The reference pattern 11a, like the other alignment patterns 11, are in the form of cylindrical patterns passing through diameter d3, and are located at a distance d4 from the edge of the plate 10a.

In addition, the grooves 121 and 122 have an identical shape, namely a straight through light shape with circular ends of a diameter equal to the width of the channel.

Taking as reference the material triangle between the center O of the plate 10a and two consecutive vertices B and C of the plate 10a, namely the equilateral triangle OBC represented on the Figure 9A the grooves 122 are drilled parallel to the BC side from the line OB to the height OH, H being the middle of the segment BC, and the grooves 121 are drilled parallel to the BC side from the OC line up to the height OH. In addition, starting from the center O of the plate 10a along the line OH, the first groove 121 is distant by a length d1 'from the center O of the plate 10a, the first groove 122 is distant by a length d2' of the first groove 121 and the second groove 121 are spaced apart by a length d3 'of the first groove 122. The distance between a groove 121 and the following groove 122 then remains fixed at d2', and between a groove 122 and the groove 121 next to d3 '.

These grooves 121 and 122 are then reproduced by central symmetry six times at an angle of 60 ° with respect to the central axis X of the plate 10a. For the last symmetry, the ends of the grooves 121 and 122 do not terminate along the line OH ', as shown in FIG. Figure 9A , but at a distance d5 on both sides of the line OH '.

Moreover, as can be seen on the Figure 9B the grooves 121 have a width d6 and the grooves 122 have a width d7. The hexagonal central pattern M has equal sides and a width L3.

Referring now to Figures 10 and 10A the second plate model 10b of the heat exchanger 50 is shown according to the second embodiment of the invention.

The second plate model 10b is of the same size as the first plate model 10a, namely with a hexagonal shape with equal sides of width L2. Similarly, the plate 10b has six alignment patterns 11 at the corners of the hexagon, the reference pattern 11a being marked by a polarizer 13 similar to that of the plate 10a, the plate 10b having a thickness e3 here.

The figure 10A , top view of the plate half 10b of the figure 10 shows that this plate model 10b has grooves 12 in circular and oblong form. Firstly, the plate 10b has grooves 121 of circular shape for the fluid C1 and circular grooves 122 for the fluid C2. The grooves 121 have a diameter d6 and the grooves 122 have a diameter d7. These grooves 121 and 122 are made along the diagonals of the hexagon and according to the OH heights presented above with reference to the figure 10A . In addition, the spacing between the grooves 121 and 122 is identical to that of the grooves 121 and 122 of the first hexagonal plate model 10a, namely the distances d1 ', d2' and d3 '.

Moreover, on one of the sides of the hexagon, the circular grooves are replaced by grooves in the form of oblong holes 123 for the fluid C1 and 124 for the fluid C2, respectively of width d6 and d7, centered according to the right OH '. The distance along the line OH 'between two consecutive oblong holes 123 or consecutive 124 is d2' + d3 ', and the width of these holes 123 and 124 following the normal to the right OH' is 2 x d5.

We will now describe with reference to Figures 11 and 12 respectively, the third 10c and the fourth 10d types of plates used in the heat exchanger 50 according to the second embodiment of the invention.

These two plates 10c and 10d have the same dimensions as the previous plates 10a and 10b, namely a hexagon shape with equal sides of width L2. The alignment patterns 11, including the reference pattern 11a, and the polarizer 13 are identical to those previously described for the plates 10a and 10b.

The respective thicknesses of the plates 10c and 10d are e4 and e5. In addition, the plates 10c and 10d also comprise a hexagonal central unit M of width L3.

The plate 10c has a groove 12, in the form of a circular groove 12a, with a diameter d7, which will be superimposed on the last groove 122 of the plate 10a.

The plate 10d has in turn a groove 12, in the form of a circular groove 12b, of diameter d6, which will be superimposed on the first groove 122 of the plate 10a.

Moreover, the figure 13 represents, schematically in perspective, an example of alignment tooling 20 of the plate heat exchanger 50 10a, 10b, 10c, 10d, in the form of an alignment stud 13 which will serve as a guide during the mounting. This alignment stud 13 has the shape of a chamfered cylinder of length L3 and diameter d3.

By way of nonlimiting examples, each plate 10a, 10b, 10c and 10d may be made of metal, in particular stainless steel, for example of the type X2CrNiMo17-12-02 1.4404 according to the European standard EN 10027, with a thickness e2 = e3 = e4 = e5 of the order of 0.5 mm for a width L2 of the order of 84 mm.

The alignment patterns 11 and / or the grooves 12 may be made by laser cutting and, unless otherwise indicated, the tolerances on the final dimensions may be of the order of ± 0.05 mm. In addition, the alignment patterns 11, here the number of 6, may have a diameter d2 of the order of 2 mm, being located at a distance d3 of the order of 2 mm from the edge of the plates.

Furthermore, the grooves 121 and 122 may be of respective width d6 of the order of 1 mm and d7 of the order of 1.6 mm. The remaining dimensions can be: d1 '= 2.7 mm; d2 '= d3' = 2.3 mm; d5 = 2.6 mm; and L3 = 3.4 mm.

The figure 14 represents the final stack, in an exploded view, of the heat exchanger 50 obtained through a plate 10a, a plate 10b, a plate 10c, a plate 10d and a plate referenced 10a 'because it corresponds to a plate 10a returned.

More precisely, the stack represented on the figure 14 is constituted from the bottom up by a plate 10c, a plate 10a, a plate 10b, a second plate 10a returned, denoted 10a ', and a plate 10d. Thus, all the plates are arranged with a top view identical to the figures 9 , 10 , 11 and 12 , except for the second plate 10a '. Indeed, to allow the formation of the channels from the grooves 121 and 122, the latter must be returned, the top face shown on the figure 9 lying below in the stack.

The reference patterns 11a are therefore superimposed for all the plates, except the second plate 10a 'for which the polarizer 13 is then located on another vertex of the hexagonal stack.

The assembly is performed so that straight lines OH 'described above are all parallel to each other. Two alignment tools 20 are needed in order to maintain the alignment of the plates together during the further manufacturing.

We will now describe the continuation of the manufacture of the heat exchanger 50 from the stack of the figure 14A .

The sealing of the plates relative to each other of the heat exchanger 50 is performed by diffusion welding assisted by Uniaxial Hot Compression (CUC).

For this, it is necessary to have a press to work at high temperature under vacuum or under neutral gas.

• une fois l'empilement des plaques réalisé et correctement alignées les unes par rapport aux autres, l'assemblage est placé entre les deux plateaux de la presse,
• un pompage permet de réaliser un taux de vide suffisant au niveau de l'empilement, soit environ une pression de 10^-3 mbar minimum ; il est possible également de travailler sous gaz neutre (du type argon, azote) : pour cela, il faut alterner des phases de dégazage et de remplissage afin d'obtenir une atmosphère la plus propre possible,
• l'empilement subit ensuite le cycle de Compression Uniaxiale à Chaud (CUC) qui comprend un chauffage en 3 heures à une température de 1020°C avec une augmentation de charge jusqu'à 10 MPa, un palier de 3 heures à une température de 1020°C sous 10 MPa, puis un refroidissement en plusieurs heures, et enfin un déchargement.

An example of a CUC assisted diffusion welding procedure for the above examples of 316L stainless steel is described below:

• once the stack of plates is made and correctly aligned with each other, the assembly is placed between the two plates of the press,
• pumping makes it possible to achieve a sufficient vacuum level at the level of the stack, ie a pressure of at least 10 ^-3 mbar; it is also possible to work under neutral gas (argon, nitrogen type): for this, it is necessary to alternate degassing and filling phases in order to obtain the cleanest possible atmosphere,
• the stack then undergoes the Uniaxial Hot Compression (CUC) cycle which comprises heating in 3 hours at a temperature of 1020 ° C with a charge increase of up to 10 MPa, a plateau of 3 hours at a temperature of 1020 ° C under 10 MPa, then cooling in several hours, and finally unloading.

Of course, this procedure is given only as an example in specific cases. It is in no way limiting as to the possibilities of realization using this assembly technique.

As visible on the figure 15 once the heat exchanger 50 made using Uniaxial Hot Pressed (CUC) assisted diffusion welding in this example, a notch 30 is made in the center of the side face of the heat exchanger 50 located between the 13 of the plate 10a 'and plates 10a, 10b, 10c and 10d.

With reference to figures 16 , 17 and 17A , as for the first embodiment of the invention according to the figure 3 for example, the plates 10a, 10a 'and 10b are presented in negative to better understand the stack, the channels 11' formed by the alignment patterns 11, and the channels 121 'and 122' formed by the grooves 121 and 122 being in relief, the rest of the plates being transparent.

The figure 16 thus presents the plate 10a seen in negative. When the two plates 10a and 10a 'are superimposed, the plate 10a' being inverted with respect to the other plate 10a, as according to the figure 17 the lines OH 'being parallel, the formation of the channels 121' and 122 'from the grooves 121 and 122 is visible all around the assembly except at the line OH'. Thus, the addition of a plate 10b, as according to the Figure 17A , can overcome this problem and achieve the continuity of the grooves. The present invention thus makes it possible to use a single plate model, namely the first plate model 10a, in two different configurations for producing a plate heat exchanger 50.

Of course, the invention is not limited to the embodiments which have just been described. Various modifications may be made by the skilled person.

In particular, the invention can be applied for the realization of an evolutionary channel geometry plate heat exchanger. In particular, it is possible to change the geometry of the fluid circulation channels throughout of the heat exchanger. Indeed, it is possible to modify the repetition angle θ3, or no offset, alignment patterns 11 over the entire length of the heat exchanger 50, as the grooves 12 of a plate are slightly in look at those of adjacent plates to form a channel. This has the advantage in some cases to intensify trade in some critical areas while others do not require it.

Moreover, the compactness and the integrity of the heat exchanger after manufacture can also be optimized by integrating the fluid collectors C1 and C2 flowing in the channels formed from the grooves 121 and 122 respectively directly during the mounting phases of FIG. the heat exchanger.

Moreover, the hollow patterns represented in the examples described above correspond to through-holes formed in particular by removal of material. As a variant, the hollow patterns may also correspond, in whole or in part, to shaped depressions without removal of material, for example by stamping. At least one continuous channel can then be formed by superposition of at least two plates comprising such stamped hollow patterns, one of the plates being returned relative to the other and optionally offset by a predetermined angle with respect to the other to put the stamped hollowed patterns at least partially.

Claims (15)

A method of manufacturing at least one plate heat exchanger (50) (10; 10a-10d) to at least two fluid circuits (C1, C2), characterized in that it comprises the following steps: a) forming a plurality of plates (10; 10a-10d) constituting the heat exchanger (50), each plate (10; 10a-10d) having a dug pattern referred to as a "reference pattern" (11a), b) forming one or more dug patterns comprising the reference pattern (11a), called "alignment patterns" (11) on each plate (10; 10a-10d) by circular repeating the reference pattern (11a) around an axis of revolution (X) of the plate (10; 10a-10d), the axes of revolution (X) of the plates (10; 10a-10d) being merged, c) forming a plurality of grooves (12) for forming the fluid circulation channels (C1, C2) of the plate heat exchanger (50), on each plate (10; 10a-10d), the grooves (12) comprising at least a first plurality of grooves (121) for the first fluid circuit (C1) and a second plurality of grooves (122) for the second fluid circuit (C2), and in that it further comprises the following successive steps: d) assembling the plates (10; 10a-10d) superimposed with respect to each other, each reference pattern (11a) of a first plate being superimposed on an alignment pattern (11) of a second adjacent plate at the first plate, e) performing an assembly treatment on the assembly obtained at the end of the preceding step d) by soldering-diffusion, brazing and / or soldering-diffusion. Process according to Claim 1, characterized in that the step d) of assembling the plates (10; 10a-10d) comprises the following successive sub-steps: i) disposing a first plate (10; 10c) on a support, ii) superimposing a second plate (10; 10a) on the first plate (10; 10c) by aligning the reference pattern (11a) of the second plate (10; 10a) with an alignment pattern (11) of the first plate (10; 10c), iii) placing an alignment tool (20) at the coincident patterns formed by the reference pattern (11a) of the second plate (10; 10a) and the alignment pattern of the first plate (10; 10c), the alignment tooling (20) for maintaining the coincidence of said patterns (11a, 11), iv) optionally, placing another alignment tool (20) at two other coincident patterns formed by an alignment pattern (11) of the first plate (10; 10c) and an alignment pattern (11) of the second plate (10; 10a), superposed between them and different from the patterns used in step ii), v) superimposing N plates (10; 10b, 10a ', 10d), N being an integer greater than or equal to 1, to the second plate (10; 10a), each ^Nth plate (10; 10b, 10a', 10d ) being superposed by coincidence of its reference pattern (11a) with an alignment pattern (11) of the plate with which it is superimposed according to the principle of step ii), and using at least one tool of alignment (20) according to the principle of step iii). Method according to Claim 2, characterized in that the alignment tool or tools (20) have a transverse dimension, in particular a diameter (d2; d3), substantially equal to the transverse dimension, in particular the diameter (d2; d3), alignment patterns (11) of the plates (10; 10a-10d Process according to one of Claims 1 to 3, characterized in that step e) of carrying out an assembly treatment comprises diffusion-bonding and / or soldering-diffusion, in particular by the isostatic compression technique. (CIC) and / or by the hot uniaxial compression (CUC) technique. Process according to one of Claims 1 to 3, characterized in that the step e) of carrying out an assembly treatment comprises brazing. Method according to one of the preceding claims, characterized in that the angle (θ3) of the circular repetition, called the "angle of rotation", of the reference pattern (11a) of each plate (10; 10a-10d) around the axis of revolution (X) considered of the plate (10; 10a-10d) is identical for all the plates (10; 10a-10d). Method according to one of Claims 1 to 5, characterized in that the angle (θ3) of the circular repetition, called the "angle of rotation", of the reference pattern (11a) of each plate (10; 10a-10d ) around the respective axis of revolution (X) of the plate (10; 10a-10d) is different for at least two of the plates (10; 10a-10d), in particular all the plates (10; 10a-10d); A method according to claim 7, characterized in that the value of each rotation angle (θ3) of the reference pattern (11a) to form one or more alignment patterns (11) is an integer multiple of the value of the angle of rotation (θ3) the smallest of all the angles of rotation forming the alignment patterns (11). Process according to one of the preceding claims, characterized in that it is used for the production of a plurality of elementary heat exchanger modules (50), each elementary heat exchanger module plates (50) being obtained through steps a) to e),
and in that it comprises the following step: f) manufacturing a plate heat exchanger (50) by combining the individual plate heat exchanger modules (50) with each other. Method according to one of the preceding claims, characterized in that the plates (10; 10a-10d) all have an identical shape. Process according to one of Claims 1 to 9, characterized in that the plates (10; 10a-10d) have different shapes. Process according to any one of the preceding claims, characterized in that the plates (10; 10a-10d) are made of metal, in particular stainless steel. Method according to one of the preceding claims, characterized in that each plate (10; 10a-10d) has a registration element (13) to enable the position of said at least one reference pattern (11a) of the plate to be known. (10; 10a-10d). Method according to Claim 13, characterized in that the locating element (13) is in the form of a notch (13) formed at the periphery of the plate (10; 10a-10d). Plate heat exchanger (50) with at least two fluid circuits (C1, C2), characterized in that it is obtained by means of the method according to any one of the preceding claims.

Images