EP3861270A1

EP3861270A1 - Plate for a plate heat exchanger

Info

Publication number: EP3861270A1
Application number: EP19769513.3A
Authority: EP
Inventors: Henricus NEEFS; Constantin Popescu
Original assignee: Axens SA
Current assignee: Axens SA
Priority date: 2018-10-01
Filing date: 2019-09-20
Publication date: 2021-08-11
Also published as: FR3086742A1; KR20210065990A; WO2020069880A1; US20210389060A1; CN113167543A; FR3086742B1; CN113167543B

Abstract

The invention relates to a heat exchanger plate (A; B) comprising a central panel (A0; B0) with at least four sides (A1, A2, A3, A4; B1, B2, B3, B4), said central panel preferably being quadrilateral or quadrilateral with truncated corners, said plate having: - a first side (A1; B1) of the central panel which is inclined in relation to the central panel (A0; B0) and which forms a first junction panel (JA; JB), - the opposite side (A3; B3) from the first side (A1; B1) which is flat.

Description

PLATE FOR A PLATE HEAT EXCHANGER

FIELD OF THE INVENTION

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.

The heat exchangers which are particularly advantageous for the invention are gas-gas exchangers which operate with large or small flow volumes at relatively low pressures, for example from 0.1 to 1.5 MPa. They can be used for example in the form of air preheaters for ovens or can be part of NOx reduction installations (“DeNOx” devices).

The function of heat exchangers is to carry out 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 supplied alternately to the successive channels so as to effect a heat transfer between the high temperature fluid and the low temperature fluid through each plate.

STATE OF THE ART:

Patent EP165179B1 describes a plate heat exchanger characterized in that the channels are defined by the space included between pressed quadrilateral plates. Said pressed plates comprise two pairs of opposite edges bent at 90 ° in opposite directions: a pair upwards and a pair downwards when 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 the outlet of each channel are identical. Each pressed plate requires at least four folding operations for its manufacture.

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 which are positioned by being a mirror image with respect to each other. Consequently, 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.

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 preferably without affecting the performance of the heat transfer. and resistance to corrosion, in particular resistance to corrosion by cracking.

SUMMARY OF THE INVENTION:

The heat exchanger plate according to the invention, comprising a central panel with at least four sides, said central panel preferably being quadrilateral or quadrilateral with truncated corners, can be defined as follows:

a first side of the central panel is inclined relative to said central panel and forms a first junction panel

- the opposite side of said first side is plane.

It is specified that a “flat” side within the meaning of the invention is to be understood with its usual meaning, namely that the side is entirely flat, from one end to the other of the edge in question, and it therefore does not include no portion which would not be, and which, for example would be tilted.

By comparison with the heat exchanger plates already known, the plate according to the invention is produced with a reduced number of operations, insofar as only one folding operation is required to manufacture the plate. The heat exchanger plate has a heat transfer performance similar to that of conventional heat exchanger plates.

By comparison with the heat exchanger plates already known, a single junction panel on two successive heat exchanger plates is possibly sufficient to connect them mechanically.

Compared with the heat exchanger plates already known, the corrosion resistance of the heat exchanger plate according to the invention is improved. The plate according to the invention makes it possible to maintain the temperature of the wall of the plate above the dew point of the fluid, while a hot gas flows at the level of the entry and the exit of the channel of the 'heat exchanger, which reduces the risk of corrosion under the effect of condensed acids. In addition, the design of the inlet and outlet of the channel has a geometry with a lower risk of corrosion by cracking since the number of curved edges is reduced. By comparison with the heat exchanger plates already known, the plate according to the invention can be welded in such a way that it is not necessary to compensate for the expansion of the corners of the plate and that it is not necessary to '' use a dedicated expansion device in the chassis (“casing” according to English terminology) of the heat exchanger.

Advantageously, the first junction panel of the heat exchanger plate according to the invention comprises a first part, in particular a single part, said first part forming an angle a with said central panel. In this way, the plate is very easy to manufacture.

Advantageously, the first junction panel of the heat exchanger plate according to the invention is made from a first part and from a second part extending from said first part, said first part forming an angle a with the central panel and said second part being parallel to the central panel. The first joint panel can be made with both parts in a single folding operation. The second part can advantageously be used to weld the first junction panel to another heat exchanger plate. Thus, the plate with a single junction panel can be manufactured in a single folding operation. Therefore, the plate is very easy to manufacture and can be very easily assembled with another plate.

In the latter two cases, the angle a between the first part of the first junction panel and the central panel is preferably between 10 ° and 90 °, preferably between 20 ° and 60 °, and more preferably between 30 ° and 50 °.

According to a first embodiment of the invention, a second side of the central panel of the heat exchanger plate according to the invention can be inclined relative to the central panel, said second side being adjacent to the first side and said second side forming a second junction panel inclined in the opposite direction relative to the first junction panel. Furthermore, the opposite side of said second side can be either flat or inclined so as to form a third junction panel, said third junction panel being a mirror image of said second junction panel.

In this first embodiment, the second junction panel can be used to mechanically connect the central panel of said heat exchanger plate to another heat exchanger plate.

In this first embodiment, either the opposite side of said second side is planar and the two junction panels of the heat exchanger plate according to this embodiment can be mechanically connected to two heat exchanger plates comprising two panels junction, each of the junction panels being connected to one of the two plates. Or, alternatively, the opposite side of said second side is inclined so as to form a third junction panel which is a mirror image of said second junction panel, that is to say that the edge opposite to the second junction panel is tilted in the same direction as the second panel of junction. The heat exchanger plate with three junction panels can be mechanically connected to two other heat exchanger plates having only a first junction panel, the first junction panel being connected to a plate and the second and third panels junction being connected to the other plate.

Advantageously, in this first embodiment of the invention, the second junction panel of the heat exchanger plate according to the invention comprises a first part, in particular a single part, said first part forming an angle b with the panel central. In this way, the plate is very easy to manufacture.

Advantageously, in this first embodiment of the invention, the second junction panel of the heat exchanger plate according to the invention is made from a first part and from a second part extending from said first part, said first part forming an angle b with the central panel and said second part being parallel to the central panel. The second junction panel can be manufactured with the two parts in a single folding operation, so that the plate with two junction panels can be manufactured in two folding operations. The second part of the junction panel can be used to weld the second junction panel to another heat exchanger plate. Therefore, the plate is very easy to manufacture and very easy to assemble with two other plates having two junction panels. The third junction panel, if any, is a mirror image of the second junction panel and requires a third folding operation. However, the plate with three junction panels can be assembled with two plates having only a first junction panel so that overall, the production of a pair of plates requires only four folding operations.

Advantageously, in the last two cases of the first embodiment, said angle b between the first part of the second junction panel and the central panel is between 10 ° and 120 °, preferably between 20 ° and 1 10 °, and more preferably between 30 ° and 100 ° or, in particular, is 45 ° or 90 °.

Another object of the present invention is a pair of heat exchanger plates comprising two spaced heat exchanger plates, as described above, i.e. a first and a second exchanger plate heat, whose central panels are parallel to each other, in which

the first junction panel of the first heat exchanger plate and the first junction panel of the second heat exchanger plate are arranged so as to face each other, the first junction panel of said first heat exchanger plate is fixed directly to the central panel of the second heat exchanger plate on said opposite plane side,

the first junction panel of said second heat exchanger plate is fixed directly to the central panel of the first heat exchanger plate on said opposite plane side,

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

The two plates of the pair of plates according to the invention are assembled by their first junction panels. The space between the two plates forms the first channel for receiving a first fluid. The first channel has a trapezoidal section which remains identical over its entire length. The speed of the fluid is substantially constant over the entire length of the channel, which may be advantageous depending on the nature of the fluids.

As the manufacturing time of each heat exchanger plate is reduced compared to that of conventional heat exchanger plates, the manufacturing time of the pair of plates is also reduced.

Another object of the present invention is a stack of pairs of heat exchanger plates, comprising two pairs of successively spaced plates as described above, a first pair of heat exchanger plates and a second pair of plates heat exchanger, in which:

said first pair and said second pair are arranged parallel to each other, the space between the first and second pair of heat exchanger plates forms a second channel for receiving a second fluid,

preferably, said second pair is identical to said first pair, or said second pair is a mirror image of said first pair.

The stack of two pairs of successive spaced plates according to the invention makes it possible to form the second channel for receiving a second fluid. The second channel has a section which varies along the length of the second channel. The speed of the fluid varies over the length of the channel, which may be advantageous depending on the nature of the fluids. The manufacturing time of each pair of heat exchanger plates is reduced compared to that of conventional pairs of heat exchanger plates, so that the manufacturing time of the stack of pairs of plates is also reduced.

Advantageously, the two successive pairs of the stack of pairs of plates according to the invention are connected laterally by closing means, said closing means comprising preferably a side bar, a cover plate with a C or U profile, or a flat cover plate of hexagonal or pentagonal shape.

According to a first embodiment of the invention, called “single junction panel” mode throughout the present text, the heat exchanger plates according to the invention do not have a second junction panel.

According to another embodiment of the invention, called “two junction panel” mode throughout the present text, the stack of pairs of heat exchanger plates as described above said second pair being preferably identical to said first pair, comprises heat exchanger plates such that a second side of the central panel is inclined relative to the central panel, said second side being adjacent to the first side and said second side forming a second junction panel being inclined in the opposite direction from the first junction panel, and the opposite side of said second side is planar. The stack according to the invention is then such that:

advantageously, the second junction panel of the second heat exchanger plate of the first pair is fixed directly to the central panel of the first heat exchanger plate of the second pair and the second junction panel of the first plate heat exchanger of the second pair is fixed directly to the central panel of the second heat exchanger plate of the first pair,

- as an option, either closure means can connect said two pairs laterally, on the side of the second junction panels, or the corner area at the intersection between the first and second junction panels can be shaped so as to mechanically connect said two pairs.

The stack of two pairs of successive plates spaced apart according to this embodiment of the invention allows the first and second junction panels to be used to mechanically connect the heat exchanger plates. The manufacturing time of each pair of heat exchanger plates is reduced compared to that of conventional pairs of heat exchanger plates, and the manufacturing time of the stack of pairs of plates is also reduced.

When the corner area at the intersection of the first and second junction panels is formed to mechanically connect the two pairs of plates, it may not be necessary to use cover plates.

In the “two junction panels” mode, the stack of pairs of heat exchanger plates can advantageously comprise heat exchanger plates in which said second junction panel of each plate of the stack comprises a first part, in particular a single part, said first part forming an angle b with the central panel, or in which said second junction panel of each plate of the stack is made to starting from a first part and from a second part extending from said first part, said first part forming an angle b with the central panel and said second part being parallel to the central panel.

Another object of the invention is a plate heat exchanger comprising the heat exchanger plates and / or pairs of heat exchanger plates and / or a stack of pairs of heat exchanger plates as described previously, arranged in an appropriate frame (“casing” according to English terminology).

The present invention also relates to a method of manufacturing a pair of heat exchanger plates as described above, said method comprising the following steps:

preparing two central panels, preferably quadrilateral, possibly truncated, comprising a first side and a second side adjacent to the first, for each of said central panels, folding said first side so as to form a first junction panel, said first junction panel comprising a first part, in particular a single part, said first part forming an angle a with the central panel,

optionally, for each of said central panels, fold said second side so as to form a second junction panel, said second junction panel comprising a first part, in particular a single part, said first part forming an angle b with the central panel,

arrange the two heat exchanger plates so that their first junction panels are facing each other and their central panels are parallel to each other,

join the two heat exchanger plates so as to form a pair of plates, the space between the two plates forming a first fluid channel, mechanically fix the two plates along their first junction panels.

Assembling the pair of heat exchanger plates is easy and has a reduced number of bending operations, which reduces manufacturing costs and time.

The present invention also relates to a method for manufacturing a stack of pairs of heat exchanger plates as described above, said method comprising:

prepare at least four central panels, preferably quadrilateral, possibly truncated, having a first side and a second side adjacent to the first,

for each of said central panels, folding said first side so as to form a first junction panel, said first junction panel comprising a first part, in particular a single part, said first part forming an angle with the central panel, optionally, for each of said central panels, fold said second side so as to form a second junction panel, said second junction panel comprising a first part, in particular a single part, said first part forming an angle b with the central panel,

arrange the heat exchanger plates in pairs so that their first junction panels are facing each other, facing each other, and that their central panels are parallel to each other,

join the heat exchanger plates so as to form at least two pairs of plates, the space between the two plates forming a first fluid channel, mechanically fix the two plates of each pair along their first junction panels,

stacking the at least two pairs of plates, the space between the pairs of heat exchanger plates forming a second fluid channel,

Optionally, mechanically fix the two pairs of plates along their second junction panels.

In the embodiment of the invention with a “single junction panel”, the plates of the heat exchanger can be substantially identical, and are preferably identical, which makes assembly easier and reduces manufacturing costs. : to form a stack of pairs, it suffices only, for example, to prepare a first stack of plates, and a second stack of plates in which the plates, in particular all identical, have undergone a rotation of 180 ° and have been turned over. Then, the plates are taken alternately from the two stacks to progressively manufacture the stack. The process can be automated.

In the embodiment of the invention with "two junction panels", the plates of the heat exchanger can be substantially similar: the second junction panel is located alternately on one side and on the other of the first junction panel, for two plates which follow one another in the stack of plates. Indeed, the second junction panels can thus be opposite one another when two successive pairs are assembled. This makes assembly easy and reduces manufacturing costs: to form a stack of pairs, it suffices only, for example, to prepare a first stack of plates of the first type and a second stack of to make the stack. The process can be automated.

DESCRIPTION

Throughout this text, the terms “supply” or “inlet” and “outlet” or “discharge” and “in” or “out of” are used with reference to the direction of flow of the fluids. Throughout the present text, the term “side” of the central panel is used with reference to the periphery of the central panel, over a certain width, for example up to 5% of the width of the plate.

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

The invention can be used for example for plate heat exchangers operating according to the cross-flow principle 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. The invention can also be used for plate heat exchangers operating according to a co-current flow principle 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 invention is particularly suitable for the 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 an oven and the fumes from the same oven or similarly, the hot stream from a NOx reduction system and the cold stream from the same NOx reduction system.

A plate heat exchanger according to the invention can be used for fluids operating at a pressure ranging from the total vacuum pressure up to 1.5 MPa, preferably from 0.1 to 1.0 MPa, more preferably from 0.1 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. Correspondingly, the height of the first junction panel and the heights of the second and third junction panel, if any, may be similar or different.

The height of the channels (the spacing between two consecutive plates) can be determined according to the operating conditions. Typically, it can be from 5 to 30 mm, in particular from 5 mm, 10 mm, 15 mm, 20 mm, 30 mm or any suitable height whatsoever.

The width of the heat exchanger plate according to the invention can typically be between 1,000 mm and 2,000 mm, preferably between 1,300 mm and 1,700 mm. The length of the plate heat exchanger according to the invention may typically be between 1,000 mm and 7,500 mm, preferably between 1,500 mm and 7,000 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, possibly with truncated corners.

The central panel includes a first face (or lower face) and a second face (or upper face) opposite the first face. The first and second faces may be flat but may also locally include reliefs, grooves or protuberances.

Advantageously, protuberances (“dimples” according to English terminology) can be added or pressed into the central panel of the plates. Outgrowths can be implemented on one face 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 outgrowths. The protuberances can be used as spacers and are provided to minimize deformation of the plates when stacked on top of each other. Single or double growths are typically distributed over the surface of the central panel of the heat exchanger plates.

Optionally, pin or picot fins (“fine pine” according to 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 is such that:

- The first channel is located between the two heat exchanger plates of a single pair of plates according to the invention. Said two plates are mechanically connected by their first junction panels on each side. The first channel has a trapezoidal cross section and said section retains the same dimension over the entire length of the channel. The fluid enters directly at a given speed into the channel. Then, the speed of the fluid flow is constant over the entire length of the channel. The fluid also exits at the same speed. Consequently, the first channel is said to have "direct" input and output zones ("bluff" in English terminology), unlike the second channel.

- on the contrary, the second channel is located between two successive pairs spaced from two plates. The section of the channel is not constant over the entire length of the channel. Indeed, a cross section of the second channel shows that the entry and exit zones are larger than the rectangular central section of the canal. Consequently, the speed of the fluid varies over the length of the second channel: it increases when the channel section decreases in the first part of the channel (the inlet) and it decreases when the channel section increases in the last part of the channel ( the exit). Consequently, the second channel is said to have a "sharp" entry and exit zone ("Sharp" in English terminology), unlike the first channel.

In the rest of this text, the first channel with "direct" input and output is called "direct channel" and the second channel with "live" input and output is called "live channel".

According to a first mode of operation of the invention, the hot fluid to be treated in the plate heat exchanger on the hot side can be sent to the "direct channels" and the cold fluid to be treated on the cold side can be sent to "live channels".

According to a second operating mode of the invention, the cold fluid to be treated in the plate heat exchanger on the cold side can be sent to the "direct channels" and the hot fluid to be treated on the hot side can be sent to "live channels".

When the hot fluid flows in the "direct channel", the profile of the heat exchanger plate is favorable to the condensation of the vapor of the hot fluid. On the contrary, when the hot fluid flows in the "live channel", the profile of the heat exchanger plate is favorable to avoid condensation of the hot fluid.

Advantageously, closing means can be used if necessary to close the lateral sides of the second channel and 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 English terminology) or by bolting.

In a stack of pairs of plates according to the “single junction panel” mode, in which the heat exchanger plates do not have a second junction panel, the second channel is advantageously provided with means for closing its lateral side between two pairs of successive plates. Said closing means can be lateral bars ("edge bars" according to English terminology) or dedicated cover plates ("cover parts" in English terminology) or any equivalent means. The cover plates can be manufactured in one or more pieces, some having a C shape, or a U shape or any profile allowing the second plate of the first pair to be assembled and the first plate of the second pair. The shape of the cover plate can also be octagonal so as to fit in one piece with the cross section of the second channel. Closing means can be arranged longitudinally in the direction of flow of the second fluid at the inlet and the outlet of the second channel. In a stack of pairs of plates according to the “two-junction panel mode”, in which heat exchanger plates have two junction panels, the successive pairs are assembled by the second junction panel of the second plate of the first pair on one side and by the second junction panel of the first plate of the second pair on the other side.

In this case, either, closing means can advantageously be arranged longitudinally in the direction of flow of the second fluid at the inlet and at the outlet of the second channel. Said closure means may preferably be a polygonal cover plate having a quadrilateral or pentagonal shape.

Either, the corner area at the intersection between the first and second junction panels can be advantageously pressed or formed so that said corner area is used to mechanically connect the second plate of the first pair and the first plate of the second pair, so that it is not necessary to use closing means. Typically, said corner area can be stamped, embossed, pressed, hammered and enlarged enough to be welded to adjacent plate panels.

The first and second channels, in particular the second channel, can either be completely empty (free channel) or can include any type of reinforcing element such as connection bars (“connecting bars” according to English terminology) .

Advantageously, spacers (“spacers” according to English terminology) made for example from strips (“strips” according to English terminology), profiles, protrusions or pin fins, can be inserted into the channel in order to guarantee the spacing between the plates. They can be loose or can be spot welded or can be held in place using pliers ("clamps" in English terminology) U-shaped at the level of the supply and discharge.

Advantageously, the first and second junction panels, comprising a part, in particular a single part, or made from two parts, are made up of flat or substantially flat plates.

According to a preferred embodiment of the invention, the first junction panel or the second junction panel can be mechanically fixed to the central panel of the adjacent plate by any possible technique, typically by welding.

Advantageously, the second part of the first and / or of the second junction panel can be large enough to allow mechanical fixing of the second part to the central panel of the adjacent plate by any means known to those skilled in the art. According to a first variant, the second junction panel can be oriented downward relative to the plane of the central panel, with an angle b of between 10 ° and 90 °, preferably between 20 ° and 60 °, and more preferably between 30 ° and 50 °.

According to a second variant, the second junction panel can be oriented downward relative to the plane of the central panel, with an angle b of between 60 ° and 120 °, preferably between 70 ° and 110 °, and more preferably between 80 ° and 100 °.

Alternatively, the second part of the second junction panel may extend from the first part of the second junction panel parallel to the plane of the central panel, said second part being either oriented towards the inside of the channel or towards the outside of the channel. .

Each of the first, second or third junction panel can preferably be formed in one step, by deformation. The deformation can be obtained by press forming and / or by bending.

In another embodiment of the invention, different zones of the central heat exchanger panel can be provided with an insulation layer, consisting of a part of metal plate parallel to the central panel with air between the metal plate part and the central panel. Said insulation layer can locally modify the temperature of the wall of the heat exchanger plate. Said insulation layer can typically be used in the coldest areas of the cold channel and is described for example in patent CZ298773B6.

According to another embodiment of the pair of two heat exchanger plates according to the invention, a nozzle (“ferrule” according to English terminology) can be mounted over the edges of the two adjacent plates welded together, serving as a shield protecting the junction. The tip is typically made from a piece of metal sheet bent so as to be able to cover the weld joint. The end cap can be welded to each of the two plates.

The heat exchanger plate according to the invention can be formed in one piece, usually by deformation in one step of a flat metal sheet made of a weldable material, for example a steel plate or a steel plate. stainless. The first and possibly the second and third junction panels can be part of the central panel or can also be attached to them. In the “two junction panels” mode, a second step of deformation of the flat metal sheet may be required to form the second lateral junction panel. The deformations can be obtained by press forming and / or by bending. The heat exchanger plate according to the invention can also be manufactured by assembling several independent plate parts. DETAILED DESCRIPTION

Other characteristics and advantages will appear on reading the following description provided purely by way of illustration and without limitation, which should be read with reference to the appended figures, in which:

FIG. 1a represents two identical heat exchanger plates A and B according to the “single junction panel” mode, in which the heat exchanger plates do not have a second junction panel and FIG. 1b represents the corresponding pair of plates according to the invention when said plates A and B are assembled.

FIGS. 2a and 2b show two plates A and B according to the “two junction panel” mode, in which said plates have a first and a second junction panel, according to two different embodiments.

Figure 3a shows a stack of two pairs of heat exchanger plates according to a first embodiment and in Figure 3b, according to a second embodiment of the invention.

Figures 4a and 4b show an exploded view of a stack of pairs of heat exchanger plates similar to those of Figures 3a and 3b, but also illustrating cover plates and spacers.

FIG. 5 represents a stack of two pairs of heat exchanger plates according to an embodiment of the invention, in the mode with "two junction panels".

For reasons of clarity, the figures do not necessarily represent the plates in the spatial position in which they can be assembled or used.

The reference symbols 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,, A ₂ , A ₃ , A ₄ - sides of the central panel A ₀

Bt, B ₂ , B ₃ , B ₄ - sides of the central panel B ₀

J _A - first junction panel of the central panel A ₀

J _B - first junction panel of central panel B ₀ A ₅ - first part of the first junction panel J _A

A ₆ - second part of the first junction panel J _A

B ₅ - first part of the first junction panel J _B of the central panel B ₀

B ₆ - second part of the first junction panel J _B

K _A - second central panel junction panel A ₀

K _B - second junction panel of the central panel B ₀

A ₇ - first part of the second junction panel K _A

A ₈ - second part of the second junction panel K _A

B ₇ - first part of the second junction panel K _B

B ₈ - second part of the second junction panel K _B

A _g - corner area at the intersection between the first and second junction panel J _A and K _A

B _g - corner area at the intersection between the first and second junction panel J _B and K _B.

The references of the components represented remain the same from one figure to another.

Figure 1a shows two identical heat exchanger plates A and B in the "single junction panel" mode, in which the heat exchanger plates do not have a second junction panel. The central panel A ₀ is rectangular and has 4 numbered sides, clockwise, A _1: A ₂ , A ₃ and A ₄ . For the sake of brevity, all parts of Plate B are numbered the same way.

A first side A _! of the central panel is inclined with respect to the central panel and forms a first junction panel J _A The side A ₃ of the central panel situated opposite the first junction panel J _A is a flat edge. In the embodiment illustrated in FIG. 1 a, the first junction panel J _A is formed of two parts, a first part A ₅ forming an angle a with the central panel and a second part A ₆ , which is parallel to the central panel plate. The first joint panel J _A is connected by the fold line to the central panel, but it could also have been supplied as a second part and have been fixed to the central panel. The first two-part junction panel is preferably formed in a single pass, by deformation. The first junction panel J _A is oriented downwards at an angle of approximately 45 ° relative to the plane of the central panel A ₀ . The heat exchanger plate B is identical to A and is positioned symmetrically with respect to A with respect to the point located in the center of the space between plate A and plate B. This means that plate B has been arranged after being turned over and rotated by 180 °, the first junction panels of the plates A and B being opposite one another.

Figure 1b illustrates a schematic perspective view in which the two plates A and B of Figure 1a are assembled and mechanically connected to form a pair of heat exchanger plates according to one embodiment of the invention.

The two plates of Figure 1a have been superimposed so that they can be mechanically connected. The "lower face" of plate A faces the "lower face" of plate B. The first junction panel J _A of plate A faces the first junction panel J _B of plate B. The second part A ₆ of the first junction panel J _A of the plate A is welded to the planar side B ₃ of the central panel of the heat exchanger plate B. Similarly, the second part B ₆ of the first junction panel J _B of the plate B is welded to the flat side A ₃ of the central panel of the heat exchanger plate A.

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

FIGS. 2a and 2b represent a perspective view of two plates A and B according to the “two junction panel” mode, in which the heat exchanger plates have a second junction panel, according to two different embodiments.

FIG. 2a represents two heat exchanger plates A and B in a first embodiment of the mode with “two junction panels”. The plates A and B are substantially identical with a second side of their central panel A ₀ or B ₀ , respectively which is inclined relative to the central panel, on a side adjacent A ₂ or B ₂ , respectively to the first junction panel, and which forms a second junction panel K _A and K _B , respectively. It will be noted, however, that the second junction panels K _A and K _B of the plates A and B are located on opposite adjacent sides, with respect to the first respective junction panels J _A and J _B. Thus the plate B is a symmetrical image of the plate A according to a central symmetry with respect to the point located at the center of the space delimited by the plates A and B which makes it possible to associate them easily in pairs. The second junction panels K _A and K _B are made of a single part A ₇ or B ₇ which forms an angle of 90 ° with the central panel (perpendicular to the plane of the central panel). The second junction panels are preferably formed in a single pass, by deformation. The deformation can be obtained by press forming and / or by bending. In addition, the plates heat exchanger A and B are equipped with protrusions 1, which can be positioned differently on plate A and plate B.

FIG. 2b shows two heat exchanger plates A and B in a second embodiment of the “two junction panel” mode. Plates B and A are mainly similar to plates A and B in Figure 2a but the second junction panels K _A and K _B are made from two parts, the first part A ₇ and B ₇ , respectively and the second part A ₈ and B ₈ , respectively. The first part A ₇ or B ₇ is connected by a fold line to the central panel on the edge A ₂ or B ₂ , respectively and forms an angle of about 45 ° with the central panel. The second part A ₈ or B ₈ is parallel to the plane of the central panel. Another difference from Figure 2a is that the corner areas A _g and B _g at the intersection between the first and second junction panels J _A and K _A , J _B and K _B, respectively, do not have been cut out. On the contrary, said corner zones A _g and B _g have been formed so that it is not necessary to use cover plates when the two plates are assembled in pairs.

Figures 3a and 3b show a stack of two pairs of heat exchanger plates according to a first embodiment and a second embodiment of the invention.

FIG. 3a represents a first embodiment of a stack of two spaced pairs of heat exchanger plates, each pair being similar to the pair of plates A and B shown in FIG. 1b. In this embodiment, two identical pairs of two plates have been superimposed. The channel formed between the first and the second pair constitutes the second channel of the heat exchanger, which is capable of receiving a second flow of fluid F ₂ . The section of the second channel is not constant over the length of the channel. Indeed, the second fluid F ₂ enters first of all into a rectangular volume, then into a trapezoidal volume, then again into a rectangular volume. At the end of the canal, the situation is reversed: the second fluid enters a trapezoidal volume and then a rectangular volume.

FIG. 3b represents another embodiment of the stack of two spaced pairs of heat exchanger plates, each pair being similar to the pair of plates represented in FIG. 1b, but one of the two pairs having been returned to get a second pair which is a mirror image of the first pair. The channel formed between the first and the second pair constitutes the second channel of the heat exchanger, which is capable of receiving a second flow of fluid. The section of the channel is not constant and is different from the section of the channel formed in FIG. 3a. The heat exchanger plates are equipped with protrusions 1, but one could alternatively also use, for example strips or U-shaped profiles. Figures 4a and 4b show an exploded view of assemblies similar to those of Figures 3a and 3b, illustrating cover plates and spacers. All heat exchange plates are fitted with double protrusions 2.

Figure 4a illustrates the two cover plates C which are used to mechanically connect the two pairs of successive plates, arranged similarly to the pairs shown in Figure 3a. The cover plates C are octagons having the shape of the cross section of the second channel. The cover plates C can be welded to the plate B and to the plate A or can be fixed by any mechanical means. Lateral spacing bars G are produced in the first channel formed between the plates A and B. The spacing bars could also have been implemented in the second channel.

Figure 4b illustrates the two cover plates D which are used to mechanically connect the two pairs of successive plates, arranged similarly to the pairs shown in Figure 3b. The cover plates D are octagons having the shape of the cross section of the second channel. The cover plates D can be welded to the plate A and B or can be fixed by any other mechanical means. Spacer bars G are implemented in the first channel formed between the plates A and B.

FIG. 5 represents a stack of two pairs of heat exchanger plates according to the invention, in the “two junction panel” mode. Each pair consists of a plate A and a plate B, which are similar to the plates shown in Figure 2a. Plates A and B were assembled and mechanically connected by their first junction panel. Between plate A and plate B is formed a first channel capable of receiving a first fluid Spacer bars G are used in the first channel. Two pairs of identical spaced plates are superimposed and mechanically connected by their second junction panels. The channel formed between the first and the second pair constitutes the second channel of the heat exchanger, which is capable of receiving a second flow of fluid F ₂ . The section of the second channel is not constant over the length of the channel. The closure means on each side of the second channel are not shown.

Claims

1. Heat exchanger plate (A; B) comprising a central panel (A ₀ ; B ₀ ) with at least four sides (AA ₂ , A ₃ , A ₄ ; BB ₂ , B ₃ , B ₄ ), said central panel preferably being quadrilateral or quadrilateral with truncated corners, characterized in that:

a first side (A _!; B ^ of the central panel is inclined relative to said central panel (A ₀ ; B ₀ ) and forms a first junction panel (J _A ; JB),

- the opposite side (A ₃ ; B ₃ ) of said first side (A ^; B ^ is plane.

2. heat exchanger plate (A; B) according to claim 1, wherein said first junction panel (J _A ; J _B ) comprises a first part, in particular a single part, said first part forming an angle (a ) with said central panel.

3. Heat exchanger plate (A; B) according to any one of the preceding claims, in which said first junction panel (J _A ; J _B ) is made from a first part (A ₅ ; B ₅ ) and a second part (A ₆ ; B ₆ ) extending from said first part, said first part forming an angle (a) with the central panel (A ₀ ; B ₀ ) and said second part being parallel to the central panel.

4. Heat exchanger plate (A; B) according to one of claims 2 or 3, wherein said angle (a) between the first part (A ₅ ; B ₅ ) of the first junction panel and the central panel (A ₀ ; B ₀ ) is between 10 ° and 90 °, preferably between 20 ° and 60 °, and more preferably between 30 ° and 50 °.

5. Heat exchanger plate (A; B) according to one of the preceding claims, in

which :

- a second side (A ₂ ; B ₂ ) of the central panel (A ₀ ; B ₀ ) is inclined relative to the central panel, said second side being adjacent to the first side (A _!; B ^ and said second side forms a second junction panel (K _A ; K _B ) inclined in the opposite direction with respect to the first junction panel (J _A ; J _B ),

- the opposite side (A ₄ ; B ₄ ) of said second side (A ₂ ; B ₂ ) is either flat or inclined so as to form a third junction panel, said third junction panel being a mirror image of said second panel junction.

6. Heat exchanger plate (A; B) according to claim 5, wherein said second junction panel (A ₇ ) comprises a first part, in particular a single part (A ₇ ; B ₇ ), said first part forming an angle (b) with the central panel.

7. Heat exchanger plate (A; B) according to claim 6, wherein said second junction panel (A ₇ ) is made from a first part (A ₇ ; B ₇ ) and a second part (A ₈ ; B ₈ ) extending from said first part, said first part forming an angle (b) with the plane of the central panel (A ₀ ; B ₀ ) and said second part being parallel to the central panel.

8. Heat exchanger plate (A; B) according to one of claims 6 or 7, wherein said angle (b) between the first part (A ₇ ; B ₇ ) of the second junction panel and the central panel (A ₀ ; B ₀ ) is between 10 ° and 120 °, preferably between 20 ° and 110 °, and more preferably between 30 ° and 100 ° or in particular is 45 ° or 90 °.

9. Pair of heat exchanger plates (A, B), comprising two spaced heat exchanger plates according to one of the preceding claims, designated first (A) and second (B) heat exchanger plate, whose central panels (A ₀ , B ₀ ) are parallel to each other, in which:

- the first junction panel (J _A ) of said first heat exchanger plate (A) and the first junction panel (J _B ) of said second heat exchanger plate (B) are arranged so as to be to face,

- the first junction panel (J _A ) of said first heat exchanger plate (A) is fixed directly to the central panel (B ₀ ) of said second heat exchanger plate (B) on said opposite plane side ( B ₃ ),

- the first junction panel (J _B ) of said second heat exchanger plate (B) is fixed directly to the central panel (A ₀ ) of said first heat exchanger plate (A) on said opposite plane side ( A ₃ ),

- The space between said first (A) and second (B) heat exchanger plates forms a first channel for receiving a first flow of fluid (F _T ).

10. A stack of pairs of heat exchanger plates comprising two pairs of successive spaced plates according to the preceding claim, 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, the space between the first and second pair of heat exchanger plates forms a second channel for receiving a second flow of fluid, preferably, said second pair is identical to said first pair or said second pair is a mirror image of said first pair.

11. A stack of pairs of heat exchanger plates (A, B) according to the preceding claim, forming a second channel for receiving a second flow of fluid, in which said two successive spaced pairs are connected laterally by closing means ( C; D), said closure means preferably comprising a lateral bar, a cover plate with a C or U-shaped profile, or a flat cover plate of hexagonal or pentagonal shape.

12. A stack of pairs of heat exchanger plates (A, B) according to claim 10, said second pair being preferably identical to said first pair, comprising heat exchanger plates such as a second side (A ₂ , B ₂ ) of their central panel is inclined relative to the central panel (A ₀ , B ₀ ), said second side (A ₂ , B ₂ ) being adjacent to the first side (AB ^ and said second side forming a second panel junction (K _A ; K _B ) inclined in the opposite direction relative to the first junction panel (J _A ; J _B ), and the opposite side (A ₄ ; B ₄ ) of said second side (A ₂ ; B ₂ ) being plan, in which:

- the second junction panel of the second heat exchanger plate of the first pair is fixed directly to the central panel of the first heat exchanger plate of the second pair and the second junction panel of the first plate heat exchanger of the second pair is fixed directly to the central panel of the second heat exchanger plate of the first pair,

- as an option, either closing means laterally connect said two pairs on the side of the second junction panels, or the corner zone at the intersection between the first and second junction panels is formed so as to mechanically connect said two pairs.

13. A stack of pairs of heat exchanger plates according to the preceding claim, comprising heat exchanger plates in which said second junction panel of each plate of the stack comprises a part, in particular a single part, said part forming an angle (b) with the central panel or in which said second junction panel of each plate of the stack is made from a first part and from a second part extending from said first part, said first part forming an angle (b) with the central panel and said second part being parallel to the central panel.

14. Plate heat exchanger comprising heat exchanger plates and / or pairs of heat exchanger plates or stacks of pairs of heat exchanger plates according to one of the preceding claims, said plates or pairs or stacking being arranged in a suitable frame.

15. A method of manufacturing a pair of heat exchanger plates according to claim 9, said method comprising the following steps:

preparing two central panels, preferably quadrilateral, possibly truncated, having a first side and a second side adjacent to the first, for each of said central panels, folding said first side so as to form a first junction panel, said first junction panel comprising a first part, in particular a single part, said first part forming an angle (a) with the central panel (A ₀ ; B ₀ ),

arrange the two heat exchanger plates so that their first junction panels are facing each other and their central plates are parallel to each other,

join the two heat exchanger plates so as to form a pair of plates, the space between the two plates forming a first fluid channel,

mechanically fix the two plates along their first junction panels.

16. Method for manufacturing a stack of pairs of heat exchanger plates according to one of claims 10 to 13, said method comprising the following steps:

for each of said central panels, folding said first side of the central panel so as to form a first junction panel, said first junction panel comprising a first part, in particular a single part, said first part forming an angle with the central panel,

arrange the heat exchanger plates in pairs so that their first junction panels are facing each other and that their central plates are parallel to each other,

- Optionally, mechanically fix the two pairs of plates along their second junction panels.