FR3108714A1 - Plate heat exchanger - Google Patents

Abstract

The present invention relates to a pair of plates (A, B) of a heat exchanger (AB) comprising a first plate (A) and a second plate (B) of the heat exchanger, arranged facing each other and spaced from each other so as to define an internal volume able to form a channel for the flow of a first fluid (F1), and each comprising a central panel (A0, B0). Said central panels are quadrilateral or quadrilateral with possibly truncated, cut or rounded edges, and are flat and parallel to each other. Two opposite sides of the central panel (A0) of the first plate (A) are inclined with respect to said central panel (A0) in the direction of the second plate (B) and form first junction panels (P1, P2) coming into contact with the two opposite edges corresponding planes of the central panel (B0) of the second plate (B). Figure for abstract: Fig 1a

Description

Plate heat exchanger

The invention relates to the field of plate heat exchangers, used in particular for the exchange of heat between two gases, but also between two liquids or between a liquid and a gas.

Heat exchangers of particular interest for the invention are gas-gas exchangers which operate with large or small flow volumes at relatively low pressures, for example 0.01 to 1.5 MPa. They can be used for example in the form of air preheaters for furnaces or can be part of NOx reduction installations (“DeNOx” devices).

Heat exchangers have the function of implementing a heat exchange between a high temperature fluid and a low temperature fluid without mixing them. Plate heat exchangers have good thermal performance thanks to their large exchange surface, while being compact.

Plate heat exchangers recover heat by arranging a plurality of plates stacked parallel to each other at predetermined intervals. Said plates are spaced such that the space between two adjacent plates forms a channel through which a fluid can flow. A high temperature fluid and a low temperature fluid are alternately supplied to successive channels so as to effect heat transfer between the high temperature fluid and the low temperature fluid through each plate.

Patent EP165179B1 describes a plate heat exchanger whose channels are defined by the space included between pressed quadrilateral plates. Said pressed plates comprise two pairs of opposite edges curved at 90° in opposite directions: an upward pair and a downward pair if the plates are considered in a horizontal plane. The pressed plates are mounted symmetrically and are associated with each other by welding their vertical edges. In such a heat exchanger, the inlet and outlet of each channel are identical.

Patent application US2010/0006274A1 describes a plate heat exchanger consisting of quadrilateral plates having at least two opposite edges curved with respect to the heat transfer surface. Fluid channels are defined by the space between a pair of identical plates that are positioned mirror image to each other. Therefore, the two curved edges of a plate are in contact with the two curved edges of the symmetrical plate. Thus, the plates are curved on at least two opposite edges.

We also know from patent application FR 2 806 469 plate heat exchangers, where each of the plates has edges on each of its four sides: if we consider one of these plates along a horizontal plane, two of its opposite edges extending upwards allowing the junction of the plate with an upper plate, and the other two opposite flanges extending downwards allowing the junction of said plate with a lower plate. The junctions between adjacent plates are made by welding between their respective edges.

The object of the invention is to provide an improved plate heat exchanger, in particular with a plate design guaranteeing a reduced number of manufacturing operations and/or a reduced manufacturing time, and in particular, moreover, without affecting the performance the heat transfer operated by the exchanger or its robustness.

The invention firstly relates to a pair of heat exchanger plates comprising a first plate and a second heat exchanger plate, arranged facing each other and spaced from each other by so as to define an internal volume able to form a channel for the flow of a first fluid, and each comprising a central panel. Said central panels are flat and parallel to each other. Two opposite sides of the central panel of the first plate are inclined with respect to said central panel in the direction of the second plate (inwards of the pair of plates once the two plates are assembled in pairs) and form first junction panels coming in contact with the two corresponding opposite planar edges of the central panel of the second plate. Advantageously, at least one of the central panels, in particular all the central panels, are quadrilateral or quadrilateral with truncated, cut or rounded edges.

It is specified that a "flat" edge within the meaning of the invention is to be understood with its usual meaning, namely that the edge is entirely flat, from one end to the other on the side of the plate in question, and it therefore does not include a portion which would not be, and which, for example, would be inclined.

We therefore come to assemble in pairs, according to the invention, two different types of plates, one carrying on two of its opposite edges junction panels whose corresponding edges of the other plate are devoid. Compared to pairs of plates already known, those according to the invention are produced with a reduced number of operations, insofar as it is possible to obtain, in particular by bending, the first junction panels on one of the plates in one or two operations only, and that you can then directly assemble it with the other plate which can be used as it is and remain flat, without therefore requiring any prior shaping/folding step.

Preferably, the first junction panels are symmetrical to each other with respect to an axis contained in the plane of the central panel and passing through the middles of the two other sides not provided with these first junction panels, called by the continuation “first median axis”.

Said first junction panels make it possible to connect the first plate to the second plate, by securing them to one another, for example by welding.

The space between the first and the second heat exchanger plate forms a first channel for receiving a first fluid.

It should be noted that the manufacture/shaping of the plates can also include a step of cutting/folding the corners of said plates.

The pair of plates according to the invention has heat transfer performance at the same level as pairs of conventional plates, where the edges of the plates intended to be assembled are both shaped/bent in order to be welded/jointed mechanically. Note that their mechanical robustness is also maintained at the same level.

According to one embodiment, at least one of, in particular all, the first junction panels of the central panel of the first plate comprises a first part extending from the central panel and a second part extending from said first part, said first part forming an angle α with the central panel and said second part being parallel to said central panel. This is a very advantageous configuration, because it is thus possible to fix the second part of the panel, a flat surface, to an edge which is also flat and which is parallel to it, of the other plate: a fixing of the welding type is found in particular facilitated.

It should be noted that the junction panels, in particular the two parts of these junction panels, can be obtained by folding(s) of the plate, and that the inclination of the junction panel, in particular of the first part when it has two parts, does not necessarily mean a perfect angle at the bend: the intersection between the plane of the central panel and that of the joining panel can form a rounded angle / a curved transition zone. It is the same between the first part and the second part of the junction panel when it has two: the second part can extend the first with a curved transition zone between one and the other.

Advantageously, the angle α between the first part of the first junction panel and the central panel is at least 45°, preferably at least 60°, in particular between 80 and 110°, preferably close to 90° .

In fact, the width of the first part of the junction panel and its angle of inclination (α) with respect to the central panel define the spacing between the two plates (A, B): for example, for the same angle, more the first part of the junction panel will be wider, and the more the space between the two plates will be important. The junction panel thus comes, by its dimensioning and its positioning relative to the central panel, to alone determine the height of the volume in which one of the fluids will flow, once the exchanger consists of one or more of these pairs. , at a given plate size.

According to a first variant, the two other opposite sides of the central panel of the first plate (those which are not provided with the first junction panels) are inclined with respect to said central panel in the direction opposite to the first junction panels (extending towards the outside of the assembly consisting of the pair of plates therefore) and form second junction panels, in particular in order to come into contact with the corresponding plane opposite edges of the central panel of a third plate. Here, the third plate can be part of another pair of plates intended to be assembled with the pair of plates already described, in order to constitute an exchanger comprising a stack of several pairs of plates. In this case, this third plate can be of identical conformation to the second plate, and, in particular, be like it plane, devoid of junction panels on its edges: the second junction panels are fixed, for example by welding, to two planar edges of this third plate.

Preferably, said second junction panels of the second central panel are symmetrical with each other with respect to an axis contained in the plane of their central panel and passing through the middles of the two other sides, hereinafter called "second median axis »

Advantageously, at least one, in particular all, of the second junction panels of the central panel of the first plate comprises a first part extending from the central panel and a second part extending from the said first part, the said first part forming an angle β with the central panel and said second part being parallel to said central panel.

These second junction panels can therefore be of similar conformation to the first junction panels, in one or two parts therefore. They will allow, on the same principle, by their dimensioning and their inclination with respect to the central panel, to define a given spacing between the first plate and the third plate, and therefore only define the height of the volume in which another fluid will flow (generally of different composition and/or temperature-type characteristics), once the exchanger consists of several of these pairs, at a given plate size.

Preferably, the dimensioning and/or the inclination of the first and second junction panels is actually chosen different, the volume dedicated to the flow of the two fluids being different.

Advantageously, the angle β between the first part of the second junction panels and the central panel is at least 45°, preferably at least 60°, in particular between 80 and 110°.

According to a second variant, the two other opposite sides of the central panel of the second plate are inclined with respect to said central panel in the same direction as the first junction panels (therefore oriented towards the outside of the assembly formed by the pair of plates considered therefore) and form third junction panels, in particular with a view to coming into contact with the corresponding opposite edges of the central panel of a fourth plate. In this configuration, the second plate of the first pair of plates ensures the junction with another pair of plates comprising this fourth plate and which is adjacent to it once the heat exchanger is assembled. Said fourth plate in question has corresponding edges (those which are intended to ensure the junction with the third junction panels) which are preferably flat, and it can be completely flat, like the previous third plate.

Preferably, said third junction panels of the second central panel are symmetrical with each other with respect to an axis contained in the plane of their central panel and passing through the middles of the two other sides, hereinafter called "third middle axis.

Preferably one of, in particular all, third junction panels of the central panel of the second plate comprises a first part extending from the central panel and a second part extending from said first part, said first part forming an angle θ with the central panel and said second part being parallel to said central panel.

Advantageously, the angle θ between the first part of the third junction panels and the central panel is at least 45°, in particular between 80 and 110°.

Preferably, the dimensioning and the inclination of these third junction panels are similar or identical to those of the second junction panels, because they determine, as for the second panels, the spacing between two pairs of plates conditioning the volume of the space where another fluid will flow, once the heat exchanger is assembled, at a given plate size. We can thus have values for the angle β identical to the previous values for the angle θ.

According to an exemplary embodiment, the second and/or third junction panels are different from the first junction panels, in particular in width and/or in inclination with respect to their respective central panels. Indeed, the first will determine, as already seen, a given height of volume for the flow of a first heat exchange fluid, and the second/third another given height of volume for the flow of another heat exchange fluid (or a fluid identical to the first in its composition/temperature, etc.).

The first and/or second and/or third junction panels, when in two parts, can have their first and their second parts approximately in the form of a Z, with the second part extending from the first in s' away from the central panel. Alternatively, they can be approximately inverted C-shaped, with the second part folding in the direction of the central panel.

In terms of manufacturing process, preferably the first and/or second and/or third junction panels are obtained by folding the edges of the central panels of the plates. For each plate, there may be a single bending operation, or several bending operations, including two.

The invention thus also relates to a pair of plates as described above, where the first and/or second and/or third junction panels are obtained by folding the edges of the central panels of the plates.

Still in terms of process, the plates are preferably assembled together by welding between a flat edge of one of the plates and a flat part of a junction panel of the other plate, once brought into contact, whether in a single plate pair, or between two plates of two adjacent plate pairs.

The invention also relates to a stack of pairs of heat exchanger plates (A, B) comprising at least two pairs of successive plates spaced apart as described above, designated by first pair of heat exchanger plates and second pair of heat exchanger plates, in which:

- said first pair and said second pair are arranged parallel to each other and facing each other, the space between the plates of each pair forming a channel to receive a first flow of fluid (F ₁ ),

- the space between the first and the second pair of heat exchanger plates forms a channel to receive a second flow of fluid (F ₂ ), said second pair being preferably identical to said first pair or being a mirror image of said first pair.

According to one embodiment, the stack of pairs of heat exchanger plates (A, B) comprises two successive spaced pairs which are laterally connected by closing means, which preferably comprise a side bar, or a covering with a C or U profile, or a suitable, flat covering plate, for example of hexagonal or pentagonal shape.

According to an alternative or cumulative embodiment, the stack of pairs of heat exchanger plates (A, B) comprises two successive spaced pairs which are joined laterally by second or third junction panels.

The invention also relates to a plate heat exchanger comprising pairs of heat exchanger plates or stacks of pairs of heat exchanger plates as described above, said pairs or stack of pairs being arranged in a chassis.

The invention also relates to a method for manufacturing a stack of at least two pairs of heat exchanger plates as described above, said method comprising the following steps:

- prepare at least four plates each comprising a central panel with four sides,

- on the one hand, for at least two of said central panels, folding a first and a second opposite side so as to form first junction panels, said first junction panels each comprising a first part inclined with respect to the central panel, said junction panels preferably being symmetrical to one another with respect to a first median axis of the central panel;

- on the other hand, optionally, either folding said third and fourth sides of the at least two central panels in the opposite direction to the first and second joint panels so as to form second joint panels, said second joint panels comprising a first part, inclined with respect to the central panel, said junction panels being preferably symmetrical to each other with respect to a first central axis of the central panel; either folding said first and second sides of at least two of the other central panels, so as to form third junction panels, said third junction panels comprising a first part, inclined with respect to these two central panels, said second or third junction panels preferably being symmetrical to one another with respect to a second median axis of the central panel;

- arrange the heat exchanger plates in two stacks, namely a first stack of identical plates between them, and a second stack of identical plates between them and different from the plates of the first stack,

- constitute at least two pairs of plates, from a plate coming from the first pile and from another plate coming from the second pile, by fixing the first junction panels of one of the plates to the corresponding flat edges of the another plate, in particular by welding, the space between the two plates of each pair forming a first fluid channel,

- assembling between them at least two pairs of plates thus formed, the space between the pairs of heat exchanger plates forming a second fluid channel, in particular by fixing, for example by welding, the second or third junction panels d a plate of a pair to the planar edges of a plate of an adjacent pair or laterally by closing means.

In the preceding description and in the following, particular and/or preferred embodiments of the invention are described. They may be implemented separately or combined with each other, without limitation of combination when technically feasible.

Other characteristics and advantages will appear on reading the following description provided for purely illustrative and non-limiting purposes, which must be read with reference to the appended figures:

List of Figures

Figure 1a shows two heat exchanger plates A and B according to one embodiment of a variant “one pair of junction panels”.

FIG. 1b represents the corresponding pair of plates according to the invention when said plates A and B are assembled.

Figures 2a, 2b show two plates A and B according to one embodiment of a variant “with two pairs of junction panels”.

Figure 2b shows the pair of plates according to Figure 2a when said plates A and B are assembled.

Figure 2c shows two pairs of plates according to Figure 2b, assembled to each other.

Figure 3a shows two plates A and B of a pair of heat exchanger plates according to the invention in another embodiment of the variant “with two pairs of junction panels”.

Figure 3b shows the pair of plates of Figure 3a when said plates A and B are assembled.

For reasons of clarity, the figures do not necessarily represent the plates in the spatial position in which they can be assembled, then according to their position of use. The plates are indeed in all the figures, all represented according to a vertical plane. The figures remain schematic representations, all the components shown are not necessarily to scale, and have been simplified to facilitate reading.

Throughout this text, the terms "supply" or "inlet" and "outlet" or "discharge" and "in" or "out of" are used in reference to the direction of fluid flow.

Throughout this text, the term "side" or "edge" of the central panel is used in reference to the periphery of the central panel, over a certain width, for example up to 5 or 10% of the width of the plaque.

Throughout this text, the term "mirror image" means a symmetry with respect to a plane located in the middle of the space separating the object from its image.

Throughout this text, the "internal face" of a plate designates the face turned in the direction of the other plate with which it is assembled as a pair, and the "external face" of this plate is the face turned in opposite direction to the other plate of the pair in question.

The invention can be used for example for plate heat exchangers operating according to the cross-flow principle ("cross-flow exchanger" according to the English terminology) in which the fluids flowing on the two faces of each plate are directed substantially perpendicular to each other. The invention can also be used for plate heat exchangers operating according to a counter-current principle, in which the fluids flowing on the two faces of each plate are directed substantially in opposite directions ("counter-current exchanger » according to the Anglo-Saxon terminology). The invention can also be used for plate heat exchangers operating according to a principle of co-current flow in which the fluids flowing on the two faces of each plate are directed substantially in the same direction. The invention can also be used for plate type heat exchangers operating according to other flow principles.

The direction of fluid flow is determined by the design of the plates and how they are connected via the junction panels. It can be modified by baffles arranged in some of the fluid flow channels, in particular one out of two channels. The baffles start downstream of the fluid inlet areas between the plates, and extend to the fluid outlet. For example, for a co-current heat exchanger, the baffles make it possible, downstream of the fluid inlet zone, to modify the fluid flow direction for the first time to substantially 90° so that the fluid flows in the same direction as the fluid of the next channel, then the baffles allow a second modification of the direction of flow of the fluid to 90° so that the fluid flows in the direction of the exit zone of the channel.

The invention is particularly suitable for heat exchange between two fluids, in particular two gases, but can also be used to exchange heat between two liquids, or between a liquid and a gas.

The invention is more particularly suitable for the exchange between two gases, in particular gas flows at the inlet and at the outlet of a single piece of equipment, such as for example the air to be conveyed to a furnace and the fumes from the same furnace or, similarly, the hot stream from a NOx abatement system and the cold stream to the same NOx abatement system.

A plate heat exchanger according to the invention can be used for fluids operating at a pressure ranging from full vacuum pressure up to 1.5 MPa, preferably from 0.01 to 1.0 MPa, more preferably from 0.01 to 0.6 MPa.

A plate heat exchanger according to the invention can consist either of channels of uniform height, or of channels of different heights on each circuit. Accordingly, the height of the first joint panel and the heights of the second and third joint panels, if any, may be similar or different.

The height of the channels (the spacing between two consecutive plates) can be determined according to the service conditions. Typically, it may be 5 to 30 mm, especially 5 mm, 10 mm, 15 mm, 20 mm, 30 mm or any suitable height.

The width of the heat exchanger plate according to the invention can typically be between 1000 mm and 2000 mm, preferably between 1300 mm and 1700 mm. The length of the heat exchanger plate according to the invention can typically be between 1000 mm and 7500 mm, preferably between 1500 mm and 7000 mm.

The thickness of the plate can be between 0.6 mm and 6 mm, preferably between 1.5 mm and 2.0 mm.

The central panel of the heat exchanger plate according to the invention can have any suitable shape, for example trapezoidal, hexagonal or quadrilateral. The central panel is most preferably quadrilateral, in particular rectangular or square, optionally with truncated corners.

The central panel comprises a first face (or lower face) and a second face (or upper face) opposite the first face. The terms “lower” and “upper” therefore refer, by convention, to a panel arranged along a horizontal plane.

The first and the second face may be flat but may also locally comprise reliefs, grooves or protrusions.

Advantageously, growths (“dimples” according to the Anglo-Saxon terminology) can be added or pressed into the central panel of the plates. Protrusions can be implemented on one side of the plate or on both sides of the plate with several arrangements depending on the characteristics of the plate and the use of said protrusions. The protrusions can be used as spacers and are intended to minimize deformations of the plates when stacked on top of each other. Single or double dimples are typically distributed over the center panel surface of the heat exchanger plates.

Optionally, hairpin or spiked fins (“fine pin” according to the English terminology) can also be welded to the central panel of the heat exchanger plate according to the invention using resistance welding.

According to a preferred embodiment of the invention, the heat exchanger according to the invention comprises a first channel intended to receive a first fluid located between the two heat exchanger plates of a single pair of plates according to the invention. Said two plates are mechanically connected by the first two junction panels of the first plate.

According to a preferred embodiment of the invention, the heat exchanger according to the invention comprises a second channel intended to receive a second fluid located between two pairs of consecutive plates.

Advantageously, closing means can be used if necessary to close the lateral sides of the second channel and to seal the channel. Advantageously, said closure means can be mechanically connected to the plates by any means known to those skilled in the art, for example by welding, in particular by seam welding ("seam welding" according to the Anglo-Saxon terminology) or by bolting.

In the embodiment where each pair of plates comprises only one pair of junction panels, on only one of the plates of the pair therefore, the second channel can advantageously be provided with means for closing its lateral side between two pairs of successive plates. These closure means can be side bars (“edge bars” in English terminology) or dedicated cover plates (“cover parts” in English terminology) or any other equivalent means. The cover plates can be manufactured in one or more parts, some having a C-shape, or a U-shape or any profile making it possible to assemble the second plate of the first pair and the first plate of the second pair.

With regard to the embodiment of the invention where each pair of plates comprises two pairs of junction panels, that is to say where one of the plates comprises a pair of junction panels, namely the first junction panels such as previously described, and where the same plate or the other plate comprises another pair of junction panels, namely the second or third junction panels as described previously: in this case, each pair is assembled to the other by the second or third pairs of junction panels. And closure means can advantageously be arranged longitudinally along the flow direction of the second fluid (that circulating between two pairs of assembled plates) at the inlet and at the outlet of the second channel. These closure means may be a polygonal cover plate having a suitable shape.

Furthermore, the first and second channels intended to receive the fluid(s) either can be completely empty (“free” channel), or can comprise mechanical reinforcement means, such as connection bars (“connecting bars”). » according to the Anglo-Saxon terminology).

Advantageously, spacer elements ("spacers" according to the Anglo-Saxon terminology) made for example from strips ("strips" according to the Anglo-Saxon terminology), profiles, protrusions or pin fins, can be inserted into at least one/each channel in order to guarantee the spacing between the plates. They can be loose or can be spot-welded, or even be held in place using U-shaped clamps at the supply and discharge.

Advantageously, each of the junction panels comprises a part, in particular a single part, or comprises several parts extending successively from the central panel of the plate, and this or these parts are preferably all flat or substantially flat (with possible roundings in the transition/folding zones between the central panel and the part or the first part, and between two successive parts when the panel comprises several panels. In the latter case, the last part, furthest from the central panel, is flat and parallel to the planes of the central panels, to maximize the surfaces in contact forming the junction between two plates, thus facilitating their fixing to one another, their mechanical joining.

The junction panels are preferably obtained by bending operations of the plates, but can be obtained differently, and even be attached to the central panels by various conventional fastening means.

According to one embodiment of the invention, each of the junction panels can be mechanically fixed to the central panel of the adjacent plate by any conventional technique, typically by welding.

Advantageously, the second part of each of the junction panels can be large enough to allow mechanical attachment of the second part to the central panel of the adjacent plate by conventional means, known to those skilled in the art.

According to a first variant, the second junction panels can be oriented with respect to the plane of the central panel, with an angle β of between 10° and 90°, preferably between 20° and 60°, and more preferably between 30° and 50°. °, or with an angle β between 60° and 120°, preferably between 70° and 110°, and more preferably between 80° and 100°.

Preferably, the second part of each junction panel, when it comprises two parts, can extend from the first part of the junction panel parallel to the plane of the central panel, said second part being either oriented or towards the inside of the panel. space between two plates of a pair (which will serve as a channel for the flow of a fluid) of the channel, either outwards, on the other side of this space.

Each of the junction panels can preferably be formed in a single step, by forming/bending. The deformation can be obtained by press forming and/or by bending. A series of flat sheet metal forming steps may be required to form a series of side joining panels on a single plate (one or two pairs of panels).

In one embodiment of the invention, different areas of the central panel of the plates of the heat exchanger can be provided with an insulation layer, comprising a metal plate part parallel to the central panel, with air between the metal plate part and the central panel. Said insulation layer can make it possible to locally modify the temperature of the wall of the heat exchanger plate and can typically be implemented in the coldest zones of the cold channel. An example is described in patent application CZ298773.

According to another embodiment of the pair of two heat exchanger plates according to the invention, an end piece ("ferrule" according to the English terminology) can be mounted over the edges of the two adjacent plates welded together, serving as a shield protecting the junction. The end cap is typically made from a piece of sheet metal that is bent in such a way that it can cover the weld joint. The end cap can be welded on each of the two plates.

The heat exchanger plate according to the invention can be formed in one piece, usually by one-step deformation of a flat metal sheet made of a weldable material, for example a steel plate, for example steel stainless.

It should be noted that the (or some/all of them)) heat exchanger plate according to the invention can also be manufactured by assembling several independent plate parts, by conventional assembly means.

Description of figures

The references shown in the figures are indicated below in relation to the components to which they refer:

A - Heat exchanger plate A

B - Heat exchanger plate B

A ₀ - Central panel of plate A

B ₀ - Central panel of plate B

A ₁ , A ₂ , A ₃ , A ₄ – sides of the central panel

A ₀ B ₁ , B ₂ , B ₃ , B ₄ – sides of central panel B ₀

P ₁ - first junction panel of A on side A ₁

P ₂ - second junction panel from A on side A ₂

P ₃ - third junction panel from A to side A ₃

P ₄ - fourth junction panel from A to side A ₄

R ₃ - third junction panel on B on side B ₃

R ₄ - fourth junction panel on B on side B ₄

P _1A - first part of the first junction panel P ₁

P _1B - second part of the first junction panel P ₁

P _2A - first part of the second junction panel P ₂

P _2B - second part of the second junction panel P ₂

P _4A - first part of the fourth junction panel P ₄

P _4B - second part of the fourth junction panel P ₄

R _3A - first part of the third junction panel R ₃

R _3B - second part of the third junction panel R ₃

R _4A - first part of the fourth junction panel R ₄

R _4B - second part of the fourth junction panel R ₄

The references are kept from one figure to another to designate the same components.

Figure 1a shows two heat exchanger plates A and B according to one embodiment of a variant "with one pair of junction panels", in which the plate B is flat, that is to say devoid of junction panel. It represents an exploded view of the two plates facing each other and oriented with respect to each other as they will be once assembled as shown in figure 1b.

The central panel A ₀ is rectangular in shape and has 4 numbered sides, A ₁ , A ₂ , A ₃ and A ₄ . A ₁ and A ₂ are two opposite sides. A ₃ and A ₄ are two other opposite sides. All parts of plate B are numbered the same way, with B ₀ the central panel and B ₁ ,B ₂ ,B ₃ ,B ₄ its four sides.

The central panel A ₀ is provided with a (first) pair of junction panels, namely two junction panels, respectively P ₁ on the side A ₁ and P ₂ on the opposite side A ₂ , which are symmetrical to one on the other relative to a first median axis x of the central panel A ₀ . In the embodiment illustrated in FIG. 1a, each of the junction panels P ₁ and P ₂ is formed of two parts, a first part, respectively P _1A and P _2A , forming an angle α with the central panel A ₀ and a second part, respectively P _1B and P _2B , which is parallel to the central panel A ₀ . Each junction panel is connected by a fold line to the central panel A ₀ , but it could also have been supplied as a second component and attached to / attached to the central panel. Each junction panel in two parts is preferably formed in a single pass, by deformation of the plate A. The first and the second junction panels P ₁ and P ₂ are oriented at an angle of approximately 75° with respect to the plane of the central panel A ₀ .

The heat exchanger plate B has no junction panel and is substantially planar. The two central panels A ₀ and B ₀ face each other.

FIG. 1b illustrates a schematic perspective view of the two plates A and B of FIG. 1a as they are arranged relative to each other once assembled and mechanically connected at the level of the first pair of panels of junction P ₁ and P ₂ of plate A to form a pair of heat exchanger plates according to one embodiment of the invention.

The two plates of FIG. 1a have been superimposed so as to be able to be mechanically connected. The "internal face" of plate A faces the "internal face" of plate B. The first junction panel P ₁ of plate A is welded at its second part P _1B to plate B on the edge plane of side B ₁ of central panel B ₀ . Similarly, the second junction panel P ₂ of the plate A is welded at its second part P _2B to the plate B on the plane edge of the opposite plane side B ₂ of the central panel B ₀ .

The space thus formed between plate A and plate B constitutes a first channel of the heat exchanger consisting of the pair of plates according to the invention, in which a first fluid F ₁ can flow. The first channel has a trapezoidal flow cross section and said cross section is here the same over the entire length of the channel.

Figures 2a and 2b show a perspective view of two plates A and B, respectively separately then assembled, according to a first embodiment of a variant "with two pairs of junction panels", in which the exchanger plate A is provided with two pairs of junction panels, inclined in opposite directions in which and the exchanger plate B is devoid of junction panel.

In figure 2a, the central panel A ₀ of plate A is provided with two pairs of junction panels:
- on the one hand, the first junction panels P ₁ on the side A ₁ and P ₂ on the opposite side A ₂ , which are symmetrical to each other with respect to the central axis x of the central panel A ₀ , and which are oriented towards the inner face of plate A (similarly to the junction panels of Figures 1a, 1b);
- on the other hand, the second junction panels P ₃ on the side A ₃ and P ₄ on the opposite side A ₄ , which are symmetrical to each other with respect to the second median axis y, and which are oriented on the side of the external face of plate A. The median axes x and y are mutually perpendicular.

The first junction panels P ₁ and P ₂ consist of two parts, a first part, respectively P _1A and P _2A , forming an angle α with the central panel A ₀ , and a second part, respectively P _1B and P _2B , which is parallel to the central panel, and which extends outward from the panel.

Similarly, the second junction panels P3 and P4 consist of two parts, a first part, respectively P _3A and P _4A , forming an angle β with the central panel and a second part, respectively P _3B and P _4B , which is parallel to the center panel plate but extending inboard of the panel. The first junction panels P ₁ and P ₂ are oriented towards the internal face of the plate B at an angle of approximately 75° with respect to the plane of the central panel A ₀ . The second junction panels P ₃ and P ₄ are oriented on the side of the outer face of the plate A at an angle β of approximately 90° relative to the plane of the central panel A ₀ . The joint panels are preferably formed in a single pass, by deformation. The deformation can be obtained by press forming and/or by bending, after cutting the corners.

The heat exchanger plate B has no junction panel and is substantially planar. The two central panels A ₀ and B ₀ face each other.

FIG. 2b illustrates a schematic perspective view of the two plates A and B of FIG. 2a once assembled and mechanically connected at the level of the first junction panels P ₁ and P ₂ of plate A to form a pair of exchanger plates heat.

The two plates were superimposed so that they could be mechanically connected. The "internal face" of plate A faces the "internal face" of plate B. The junction panel P ₁ of plate A is welded at its second part P _1B to plate B on the flat side B ₁ of the central panel B ₀ . Similarly, the junction panel P ₂ of the plate A is welded at its second part P _2B to the plate B on the opposite plane side B ₂ of the central panel B ₀ .

The channel formed between plate A and plate B constitutes a first channel of the heat exchanger consisting of the pair of plates according to the invention, in which a first fluid F1 can flow. The first channel has a trapezoidal flow cross-section and said cross-section is the same throughout the length of the channel.

As shown in Figure 2c, the second junction panels P3 and P4 of plate A make it possible to associate plate A with a third exchanger plate, preferably identical to plate B, which would be positioned opposite the external face. of the plate A, in order to create, between the third plate and the plate A, a second space defining a channel in which a second fluid F ₂ can flow. The second channel has, in this embodiment, a rectangular flow cross-section. FIG. 2c shows plates which have on their surface “dimples” or protrusions already mentioned above, as well as, in dotted lines, spacers intended to guarantee a constant spacing between the two central panels, here in the form of sections. These elements remain optional, but can be useful especially with large plates.

FIG. 3a represents two plates A and B of a pair of heat exchanger plates according to the invention in another embodiment of the variant “with two pairs of junction panels”, in which the exchanger plate A is provided with a (first) pair of junction panels, and in which the exchanger plate B is also provided with a (third) pair of junction panels. Figure 3b shows the pair of plates when said plates A and B are assembled.

The central panel A ₀ of the plate A is provided with a first pair of junction panels: P ₁ on the side A ₁ and P ₂ on the opposite side A ₂ , which are symmetrical to each other with respect to to the median axis x of the central panel A ₀ , and which are oriented towards the internal face of the plate B, as in the preceding figures 1a-1b.

The central panel B ₀ of the plate B is provided with a third pair of junction panels: the junction panels R ₃ on the side B ₃ and R ₄ on the opposite side B ₄ , which are symmetrical to one of the 'other with respect to the median axis y' of the central panel B ₀ , and which are oriented on the side of the external face of the plate B. As in the previous figure 2a, the median axes x and y' are perpendicular to the one to the other, with the difference that here, they materialize on two different plates parallel to each other, and not on the same plate. In this embodiment, the first junction panels P ₁ and P ₂ consist of two parts, a first part, respectively P _1A and P _2A , forming an angle α with the central panel and a second part, respectively P _1B and P _2B , which is parallel to the central panel plate A ₀ , and extend from the side of the internal face of said plate.

Similarly, the third junction panels R ₃ and R ₄ consist of two parts, a first part, respectively R _3A and R _4A , forming an angle θ with the central panel B0 and a second part, respectively R _3B and R _4B , which is parallel to the central panel plate B ₀ , but which is oriented on the side of the outer face of the plate B. The first junction panels P ₁ and P ₂ are oriented downwards at an angle of approximately 90 ° in relation to the plane of the central panel A ₀ . The third junction panels R ₃ and R ₄ are oriented at an angle θ of approximately 90° relative to the plane of the central panel B ₀ . The joint panels are preferably formed in a single pass, by deformation. The deformation can be obtained by press forming and/or by bending, after cutting the corners.

FIG. 3b illustrates a schematic perspective view of the way in which the two plates A and B of FIG. 3a are assembled and mechanically connected at the level of the first and second junction panel P ₁ and P ₂ of plate A to form a pair of heat exchanger plates: The two plates have been associated and welded via the junction panels P ₁ and P ₂ on the sides B ₁ and B ₂ of the plate B in a manner similar to FIG. 2b. The channel formed between plate A and plate B constitutes a first channel of the heat exchanger, in which a first fluid F ₁ can flow. The first channel has a rectangular flow cross-section.

The third junction panels R ₃ and R ₄ of plate B make it possible in this configuration to associate plate B with a fourth exchanger plate, preferably identical to plate A, which would be positioned facing the external face of plate B, in order to create, between plate B and the fourth plate (not shown), a second channel in which a second fluid F ₂ can flow, in particular crosswise. The height of the pairs of junction panels is chosen according to the desired fluid flow.

FIG. 3b represents a cross-current exchanger operation of the flows of the fluids F ₁ and F ₂ , flows perpendicular to each other therefore, which are obtained using internal baffles (not shown) which change the direction of the fluid F ₂ , once the admission zone has passed.

The exchangers therefore comprise several pairs of plates according to the invention mounted in a frame, with alternating plates of each of the two types, for example (ABAB) n times without excluding stacks of the type (ABBA) n times, with a junction between two pairs which is done by junction panels integrated into the plates according to the invention or by additional components added, as seen above.

Claims (15)

Pair of plates (A, B) of heat exchanger (AB) comprising a first plate (A) and a second plate (B) of heat exchanger, arranged opposite each other and spaced from one other so as to define an internal volume able to form a channel for the flow of a first fluid (F ₁ ), and each comprising a central panel (A ₀ , B ₀ ), said central panels being quadrilateral or quadrilateral with possibly truncated, cut or rounded edges, and being flat and parallel to each other, characterized in that two opposite sides of the central panel (A ₀ ) of the first plate (A) are inclined with respect to the said central panel (A ₀ ) in direction of the second plate (B) and form first junction panels (P ₁ , P ₂ ) coming into contact with the two corresponding opposite planar edges of the central panel (B ₀ ) of the second plate (B). Pair of plates (A, B) according to the preceding claim, characterized in that the said first junction panels (P ₁ , P ₂ ) are symmetrical to one another with respect to a first central axis (x) of the panel central (A ₀ ). Pair of plates (A, B) according to one of the preceding claims, characterized in that at least one of, in particular all, the first junction panels (P ₁ , P ₂ ) of the central panel (A ₀ ) of the first plate (A) comprises a first part (P _1A ; P _2A ) extending from the central panel and a second part (P _1B ; P _2B ) extending from said first part, said first part forming an angle (α ) with the central panel (A ₀ ) and said second part being parallel to said central panel (A ₀ ). Pair of plates (A, B) according to the preceding claim, characterized in that the angle (α) between the first part of the first junction panel (P _1A ; P _2A ) and the central panel A ₀ ) is at minus 45°, in particular between 80 and 110°. Pair of plates (A,B) according to one of the preceding claims, characterized in that the two other opposite sides of the central panel (A ₀ ) of the first plate (A) are inclined with respect to the said central panel (A ₀ ) in the direction opposite to the first junction panels and form second junction panels (P ₃ ; P ₄ ), in particular in order to come into contact with the corresponding opposite edges of the central panel of a third plate. Pair of plates (A, B) according to the preceding claim, characterized in that one of, in particular all, the second junction panels (P ₃ ; P ₄ ) of the central panel of the first plate (A) comprises a first part (P _3A ; P _4A ) extending from the central panel (A ₀ ) and a second part (P _3B ; P _4B ) extending from the said first part, the said first part forming an angle (β) with the central panel (A ₀ ) and said second part being parallel to said central panel (A ₀ ). Pair of plates (A,B) according to the preceding claim, characterized in that the angle (β) between the first part of the second junction panels (P _3A ; P _4A ) and the central panel (A ₀ ) is at least 45°, in particular between 80 and 110°. Pair of plates (A,B) according to one of the preceding claims, characterized in that the two other opposite sides of the central panel (B₀) of the second plate (B) are inclined with respect to said central panel (B₀) in the same direction as the first junction panels (P₁,P₂) and form third junction panels (R₃;R₄), in particular with a view to coming into contact with the corresponding opposite edges of the central panel of a fourth plate. Pair of plates (A,B) according to the preceding claim, characterized in that one of, in particular all, the third junction panels (R ₃ ; R ₄ ) of the central panel (B ₀ ) of the second plate (B) comprises a first part (R _3A ; R _4A ) extending from the central panel (B ₀ ) and a second part (R _3B ; R _4B ) extending from said first part, said first part forming an angle (θ) with the central panel (B ₀ ) and said second part being parallel to said central panel (B ₀ ). Pair of plates (A, B) according to one of Claims 6 or 9, characterized in that the second (P ₃ ; P ₄ ) and/or third (R ₃ ; R ₄ ) junction panels are different from the first panels junction (P ₁ ; P ₂ ), in particular in width and/or in inclination with respect to their respective central panels. Pair of plates (A,B) according to one of the preceding claims, characterized in that the plates are assembled to each other by welding between a flat edge of one of the plates (B) and a flat part of a junction panel (P1, P2) of the other plate (A). A stack of pairs of heat exchanger plates (A,B) comprising at least two pairs of spaced successive plates according to one of the preceding claims, designated by first pair of heat exchanger plates and second pair of heat exchanger, in which:
- said first pair and said second pair are arranged parallel to each other and facing each other, the space between the plates of each pair forming a channel to receive a first flow of fluid (F ₁ ),
- the space between the first and the second pair of heat exchanger plates forms a channel to receive a second flow of fluid (F ₂ ), said second pair being preferably identical to said first pair or being a mirror image of said first pair. Stack of pairs of heat exchanger plates (A,B) according to the preceding claim, characterized in that two successive spaced pairs are connected laterally by closing means, said closing means preferably comprising a lateral bar, a plate cover with a C or U profile, or a suitable flat cover plate. Plate heat exchanger comprising pairs (A,B) of heat exchanger plates or stacks of pairs of heat exchanger plates according to one of the preceding claims, said pairs or stacks of pairs being arranged in a frame. Method of manufacturing a stack of at least two pairs (A,B) of heat exchanger plates according to one of claims 1 to 11, said method comprising the following steps:
- prepare at least four plates each comprising a central panel (A ₀ ,B ₀ ) with four sides,
- on the one hand, for at least (A ₀ ) two of said central panels, folding a first and a second opposite side so as to form first junction panels (P ₁ ; P ₂ ), said first junction panels each comprising a first part inclined with respect to the central panel, said first junction panels being preferably symmetrical with each other with respect to a median axis (x) of the central panel (A0);
- on the other hand, optionally either folding said third and fourth sides of the at least two central panels in the opposite direction to the first and second joining panels so as to form second joining panels (P ₃ ; P ₄ ), said second junction panels comprising a first part, inclined with respect to the central panel, said junction panels being preferably symmetrical to one another with respect to a median axis (y) of the central panel; or folding said first and second sides of at least two of the other central panels, so as to form third junction panels (R ₃ ; R ₄ ), said third junction panels comprising a first part, inclined with respect to these two central panels, said second or third pairs of junction panels preferably being symmetrical to one another with respect to the second median axis (y,y') of the central panel concerned;
- arrange the heat exchanger plates in two stacks, namely a first stack of identical plates between them, and a second stack of identical plates between them and preferably different from the plates of the first stack,
- constitute at least two pairs of plates, each pair being assembled from a plate coming from the first pile and another plate coming from the second pile, by fixing the first joining panels of one of the plates to the edges corresponding planes of the other plate, the space between the two plates of each pair forming a first fluid channel,
- assembling between them at least two pairs of plates thus formed, the space between the pairs of heat exchanger plates forming a second fluid channel, by fixing the second (P ₃ ; P ₄ ), or third junction panels (R ₃ ; R ₄ ) of a plate of a pair to the planar edges of a plate of an adjacent pair or laterally by closure means.