Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
  • F28F3/04—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element
  • F28F3/042—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element
  • F28F3/046—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element the deformations being linear, e.g. corrugations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D9/0031—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/12—Elements constructed in the shape of a hollow panel, e.g. with channels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D21/0001—Recuperative heat exchangers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D9/0031—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other
  • F28D9/0037—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other the conduits for the other heat-exchange medium also being formed by paired plates touching each other

Definitions

• the present 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 carrying out a heat exchange between a fluid at high temperature and a fluid at low temperature 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.
• the efficiency of plate heat exchangers is mainly determined by the heat exchange between the fluids passing through them.
• the geometry of the heat exchanger plate affects the heat exchangers.
• the plates may, in particular, be substantially planar, or else comprise portions in relief.
• Patent application FR3086742 (W02020/069880) as well as in patent application FR 3108714 (WO2021/190879) describe a plate heat exchanger, within which pairs of plates are formed.
• each plate has a central panel.
• the central panels of the two plates being parallel and spaced from each other so as to form a channel for a fluid.
• the pair of plates includes at least one junction panel between the central panels of the plates so as to assemble them and to space them.
• the junction panels are angled with respect to the central panels.
• the heat exchanges are carried out in particular through flat plates, possibly without relief. Although satisfactory, the thermal efficiency of this plate heat exchanger can be improved.
• the plates of the heat exchangers can be equipped with devices for disturbing the flow of the fluids.
• Patent application FR3003637 describes a plate heat exchanger comprising at least one pair of spaced apart substantially parallel similar plates. Said plates may have spaced grooves extending in a direction oriented at 45° to the sides of each plate.
• the second plate is of invariant shape by rotation of 90 degrees relative to an axis normal to the main panel. In this way, the grooves of the first plate are perpendicular to the grooves of the second plate. Thus, the grooves form a relief allowing the mixing of fluids to increase heat exchange.
• the heat exchange performance can be improved, and this heat exchanger only allows co-current heat exchange, but does not allow counter-current or cross-current heat exchange.
• the object of the invention is to construct a plate heat exchanger having optimized thermal performance and with a limited pressure drop.
• the invention relates to a pair of heat exchanger plates.
• Each plate has a central panel with at least one projecting groove in a channel defined by a volume internal between the plates.
• each groove of the first plate is parallel to each groove of the second plate.
• the grooves on the two plates form a relief allowing the mixing of fluids ensuring an increase in heat exchange with a limited pressure drop.
• this design can be used for co-current, counter-current, or cross-current heat exchanges.
• the invention further relates to a stack of pairs of plates, a heat exchanger comprising such a pair of plates.
• the invention also relates to a method for manufacturing such a stack of pairs of plates or such a heat exchanger.
• a pair of heat exchanger plates includes a first plate and a second heat exchanger plate, arranged opposite each other and spaced apart to define an internal volume capable of forming a channel for a flow of a first fluid, each plate comprising a central panel, said central panels of said first and second plates preferably being substantially quadrilateral with optionally truncated, cut or rounded edges, and said central panels of said first and second plates being flat and parallel to each other.
• Said central panel of each plate comprises at least one groove, preferably a substantially rectilinear groove, projecting into said internal volume, and each groove of said first plate is parallel to each groove of said second plate.
• each groove is inclined at a non-zero and non-right angle a with respect to a side of said central panel, the angle a is greater than or equal to 10°, preferably is between 10 and 80° terminals inclusive, and preferably between 30 and 70° terminals inclusive, and preferably between 40 and 50° terminals inclusive.
• each groove of said second plate is offset with respect to each groove of said first plate in a direction perpendicular to said grooves of said first and second plates.
• each central panel of each plate comprises a plurality of parallel grooves between them, and preferably regularly spaced.
• the regular spacing between said grooves of said first plate is identical to the regular spacing between said grooves of said second plate.
• the offset in the direction perpendicular to said grooves has a distance between one third and two thirds of said regular spacing, and is preferably half of said regular spacing.
• the regular spacing between two successive grooves is between 10 and 80 mm inclusive, preferably between 20 and 60 mm inclusive.
• each groove has a cross section whose shape is chosen from an arc of a circle, a semicircle, a U, a V, an ellipse, an airplane wing, a spearhead, preferably the shape is chosen from an arc of a circle and an airplane wing.
• the width of each groove is between 4 and 30 mm inclusive terminals, preferably between 6 and 25 mm inclusive terminals.
• the protrusion height of each groove is between 1.5 and 6 mm inclusive, preferably between 2 and 5 mm inclusive.
• all the grooves of the first and second plates have the same cross-section, the same width and the same projection height.
• said first plate and said second plate are connected by means of one or two junction panel(s) arranged on one or two side(s) of a central panel.
• the invention relates to a stack of pairs of heat exchanger plates comprising at least two pairs of plates according to one of the preceding characteristics, said pairs of plates being stacked in such a way that said pairs of successive plates are spaced .
• first pair of plates and second pair of plates designated respectively first pair of plates and second pair of plates: a. Said first pair of plates and said second pair of plates are arranged parallel to each other and facing each other, the space between the plates of each pair of plates forming a channel for the flow a first fluid, b. The space between said first pair of plates and said second pair of plates forms a channel for the flow of a second fluid, said second pair of plates being preferably identical to said first pair of plates, or being a mirror image of said first pair of plates.
• said channel for the flow of the second fluid is perpendicular to said channel for the flow of the first fluid.
• the invention also relates to a plate heat exchanger comprising pairs of plates according to one of the preceding characteristics or a stack of pairs of plates according to one of the preceding characteristics, said pairs of plates or said stack of pairs of plates being arranged in a frame.
• the invention relates to a method of manufacturing a stack of pairs of plates according to one of the preceding characteristics, or a heat exchanger according to one of the preceding characteristics.
• the following steps are carried out: a. At least four plates are prepared, each comprising a central panel; b. For a first half of said plates, said at least one groove is formed in the central panel of each plate, in particular by stamping; vs. For a second half of said plates, said at least one groove is formed in the central panel of each plate, in particular by stamping; d.
• At least two pairs of plates are assembled, for each pair of plates, a first plate of said first half of said plates is arranged parallel to a second plate of said second half of said plates, such that the grooves are parallel and project into the internal volume between said plates, and possibly with an offset of each groove of the first plate relative to each groove of the second plate in a direction perpendicular to said grooves; summer. Said at least two pairs of plates are stacked in parallel and spaced from each other.
• Figure 1 illustrates two central panels of a pair of plates according to one embodiment of the invention.
• Figure 2 illustrates a sectional view of two central panels of a pair of plates according to one embodiment of the invention.
• FIG. 3 illustrates a cross section (profile) of a groove according to a first variant embodiment of the invention.
• FIG. 4 illustrates a cross section (profile) of a groove according to a second alternative embodiment of the invention.
• Figure 5 illustrates a pair of plates according to a first embodiment of the invention.
• Figure 6 illustrates a pair of plates according to a second embodiment of the invention.
• Figure 7 illustrates a pair of plates according to a third embodiment of the invention.
• Figure 8 illustrates a pair of plates according to a fourth embodiment of the invention.
• Figure 9 illustrates a portion of a stack of plate pairs.
• Figure 10 illustrates three designs of a pair of plates used for the comparative example.
• FIG. 11 illustrates curves of a thermal parameter as a function of the Reynolds number, respectively for two examples of pairs of plates according to the prior art, and for a pair of plates according to one embodiment of the invention.
• 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.
• mirror image means a symmetry with respect to a plane located in the middle of the space separating the object from its image.
• 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 of plates, and the “internal face” external” of this plate is the side facing in the opposite direction to the other plate of the pair of plates in question.
• the invention relates to a pair of plates of a plate heat exchanger.
• a heat exchanger is used to exchange heat between two fluids, or between a fluid and a heat source or a cold source.
• a heat exchanger comprises at least one wall, in particular a metal wall (here a plate for a plate heat exchanger) which allows heat transfer between the two fluids or between the fluid and the heat source or the heat source. cold.
• the wall metal (the plate metal for a plate heat exchanger) can be any type including steel, aluminum, copper, etc. as well as their alloys.
• the wall may be covered with a coating.
• the wall can be made of plastic, or any similar material.
• 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 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 oven or, similarly, the hot current from a NOx reduction system and the cold stream going to the same NOx reduction system.
• the pair of heat exchanger plates comprises a first substantially flat heat exchanger plate and a second substantially flat heat exchanger plate.
• the first and second plates are assembled and arranged facing each other and spaced apart so as to define an internal volume capable of forming a single channel for the flow of a first fluid.
• Each plate includes a central panel, which serves as a heat exchange surface between the two fluids within the heat exchanger.
• the central panels are substantially planar.
• 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 central panel of the first plate is parallel to the central panel of the second plate.
• 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, especially rectangular or square, optionally with truncated, cut or rounded corners.
• the central panel of each plate has at least one projecting groove in the internal volume.
• at least one groove protrudes from the inner face of the central panel of each plate.
• the grooves on the two plates form a relief allowing the mixing of fluids in the internal volume to increase heat exchange.
• the grooves make it possible to increase the level of turbulence of at least one fluid flowing in the heat exchanger and to break the boundary layer of the flow at the level of the plate, which promotes heat exchange .
• the central panel being flat, the central panel is formed of at least one flat portion and at least one groove.
• the central panel of each plate has only projecting grooves in the internal volume; no protrusion into the external volume is provided.
• the at least one groove can be inclined at an angle ⁇ with respect to an edge of the central panel.
• this angle a can be non-zero and non-right.
• the groove is not parallel to any edge of the central panel.
• the groove is neither parallel nor perpendicular to the direction of fluid flow.
• the angle a of inclination of the grooves with respect to one side of the central panel may be greater than or equal to 10°, preferably may be between 10 and 80° limits included, very preferably between 30 and 70° terminals inclusive, and even more preferably between 40 and 50° terminals inclusive.
• the at least one groove can be rectilinear (in the plane of the central panel). This shape favors its manufacture and limits pressure drops.
• each groove of the first plate is parallel to each groove of the second plate.
• the parallelism of the grooves of the first and second plates allows a simplification of the assembly: the two plates are almost similar, and do not require a modification of the orientation of one plate relative to the other.
• each groove of the second plate can be offset with respect to each groove of the first plate in a direction perpendicular to the grooves of the first and second plates.
• each groove of the second plate is not opposite a groove of the first plate in the internal volume defined by the pair of plates.
• each groove of the second plate is inserted between two grooves of the first plate in a direction perpendicular to the grooves. The offset of the grooves promotes the optimization of the disturbance of the fluid flow in the channel, which makes it possible to increase the thermal performance of the pair of plates.
• the grooves can be manufactured by deformation, for example by rolling, by stamping, for example stamping on rubber (from English “rubber forming”), or any similar process.
• the height of the channels (the spacing between two consecutive plates) can be determined according to the service conditions of the heat exchanger. Typically it may be 5 to 30mm inclusive, including 5mm, 10mm, 15mm, 20mm, 30mm or any suitable height. In one aspect, the height of the channels may be different between the cold side of the heat exchanger and the hot side of the heat exchanger.
• the width of the heat exchanger plate according to the invention can typically be between 750 mm and 2000 mm inclusive, preferably between 1000 mm and 1700 mm inclusive.
• the length of the heat exchanger plate according to the invention can typically be between 1,000 mm and 7,500 mm inclusive terminals, preferably between 1,500 mm and 7,000 mm inclusive terminals.
• the thickness of the plate may be between 0.6 mm and 6 mm inclusive terminals, preferably between 1.5 mm and 2.0 mm inclusive terminals.
• each central panel of each plate may comprise a plurality of grooves parallel to each other (that is to say at least two grooves parallel to each other).
• the grooves of each central panel can be evenly spaced. In other words, between two consecutive grooves is inserted a flat portion of the central panel. The number of grooves makes it possible to increase the mixing of the fluids allowing to increase the thermal exchanges.
• the regular spacing (called in English “pitch”) between the grooves of the first plate can be identical to the regular spacing between the grooves of the second plate.
• the manufacture of the plates can be implemented with the same machine and similar tools, which promotes their design.
• the offset in the perpendicular direction of the grooves can have a distance comprised between one third and two thirds of the regular spacing. (“pitch”).
• the grooves of the second plate can be interposed between the grooves of the first plate.
• the offset in the perpendicular direction may have a distance substantially equal to half the regular spacing (“pitch").
• the grooves of the second plate can be inserted in the middle between the grooves of the first plate.
• the regular spacing can be between 10 and 80 mm terminals included, preferably between 20 and 60 mm terminals included.
• the regular spacing is the dimension between two vertices of successive grooves measured in a direction perpendicular to the first edge of said groove.
• each groove may have a cross section in a direction transverse to the groove (the cross section is also called profile of the groove) the shape of which is chosen from: an arc of a circle, a semicircle, a U, V, ellipse, airplane wing, spearhead (shape of the iron point attached to the end of an arrow, spear or pike), or any similar shape.
• the grooves Preferably, the grooves have an arcuate or airplane wing profile. These shapes promote the mixing of the fluid making it possible to increase the heat exchanges and have no projecting angle.
• the width of each groove can be between 4 and 30 mm, terminals included, preferably between 6 and 25 mm, terminals included.
• the width of a groove is measured from a first edge to the opposite second edge in a direction perpendicular to the first edge of said groove.
• the protrusion height of each groove may be between 1.5 and 6 mm inclusive, preferably between 2 and 5 mm inclusive.
• the projecting height of a groove is the dimension of a groove in a direction orthogonal to the plane of the central panel. It is measured without including the thickness of the heat exchanger plate, i.e. from the underside of the plate to the top of the groove.
• the width to height ratio of the grooves can be between 3 and 5, more preferably between 3 and 4. These ranges of values allow the realization of the grooves and allow a turbulent flow promoting heat exchanges.
• all the grooves of the first plate and/or of the second plate can have a constant profile, width and height over the entire length of the groove.
• the projections are identical over the entire central panel.
• all the grooves of the first and second plates have the same cross-section (profile), the same width and the same projection height.
• the projections are identical, which simplifies the manufacture of the pair of plates.
• spacers can be inserted into at least one/each channel to ensure spacing between 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.
• the first plate and the second plate can be mechanically connected by means of at least one junction panel arranged on at least one side of a central panel. The at least one junction panel is connected, in particular welded, to the central panel of at least one plate of the pair of plates.
• 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.
• 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).
• a heat exchanger plate may include a center panel and a junction panel.
• the heat exchanger plate according to the invention can preferably be formed in one piece, usually by deformation in one step of a flat metal sheet made of a weldable material, for example a metal plate, in particular steel , for example stainless steel.
• each of the junction panels can be mechanically fixed to the central panel of the adjacent plate by any conventional technique, typically by welding.
• each junction panel can be in two parts, inclined relative to each other to facilitate fixing on a plate.
• 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.
• first junction panel a junction panel which makes it possible to connect two plates of the same pair of plates
• second junction panel a junction panel which makes it possible to connect two plates of two pairs of plates (when forming a stack of pairs of plates or a heat exchanger).
• each plate can include:
• a first junction panel and a second junction panel or Two first junction panels and two second junction panels.
• the at least one junction panel may conform to one of the embodiments described in patent application FR3086742 (W02020/069880) or in patent application FR 3108714 (WO2021/190879).
• At least one of, in particular all of the junction panels 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 5 with the central panel and the said second part being parallel to said central panel.
• the junction panels in particular the two parts of these junction panels, can be obtained by bending(s) of the plate.
• the inclination of the junction panel, in particular of the first part when it comprises two parts, does not necessarily mean a perfect angle at the level of the folding: the intersection between the plane of the central panel and that of the junction panel can form an angle rounded / 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.
• the angle ⁇ between the first part of the junction panel and the central panel is at least 45°, preferably at least 60°, in particular between 80 and 110° limits included, preferably in the vicinity of 90 °.
• the width of the first part of the junction panel and its angle of inclination 5 with respect to the central panel define the spacing between the two plates: for example, for the same angle, plus the first part of the junction panel will be wider, and the greater the space between the two plates will be.
• 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.
• each pair of plates can comprise a pair of junction panels.
• each plate can include a junction panel.
• This embodiment makes it possible to produce, for two plates of a pair of plates, identical junction panels, which facilitates the manufacture of junction panels.
• the design of the junction panels of the pair of plates can be obtained by turning one plate relative to the other.
• one of the two plates can comprise the two joining panels, preferably located on opposite sides of the central panel.
• each pair of plates can comprise two pairs of junction panels.
• Each pair of junction panels may be provided on a different side of the central panels.
• each plate can comprise two joining panels on two adjacent sides of the central panel.
• One of the two junction panels being a "first junction panel”
• the other of the two junction panels being a "second junction panel”.
• This embodiment makes it possible to produce, for two plates of a pair of plates, similar junction panels, which facilitates the manufacture of the junction panels of the pair of plates.
• the design of the junction panels of the pair of plates can be obtained by turning one plate over the other.
• Figure 1 illustrates, schematically and in a non-limiting manner, two central panels of a pair of plates according to one embodiment of the invention.
• Figure 1 is a three-dimensional view illustrating the central panels of the plates.
• the pair of plates includes a first flat plate A and a second flat plate B, the two plates being parallel and spaced apart.
• the internal volume between the two plates is denoted V.
• This volume V is provided for the flow of a fluid, illustrated by the arrow F.
• the first plate A comprises a plurality of rectilinear grooves 101, parallel and projecting into the volume internal V.
• the grooves 101 form an angle a with one side of the central panel of the plate A.
• the grooves 101 are regularly spaced, by a spacing (“pitch”) denoted p.
• the second plate B comprises a plurality of rectilinear grooves 102, parallel and projecting into the internal volume.
• the grooves 102 of the second plate B are parallel to the grooves 101 of the first plate A. Consequently, they form an angle a with respect to one side of the plate B.
• the grooves 102 are regularly spaced, preferably with the same regular spacing than the regular spacing of the grooves 101 .
• the grooves 102 of the second plate B are preferably offset from the grooves 101 of the first plate in a direction DD, included in the plane of the central panel of A and perpendicular to the grooves 101 and 102.
• the angle a is 45°
• the direction DD is a diagonal of the plate A (respectively of the plate B).
• Figure 2 is a sectional view (schematic and non-limiting) of a portion of two central panels of a pair of plates Figure 1 along the direction DD of Figure 1 which is perpendicular to the grooves 101 and 102.
• This figure represents a portion of the plate A, a portion of the plate B, and the internal volume V between the two plates A and B.
• the grooves 101 and 102 are arranged according to a regular spacing noted p.
• This figure shows the offset s between the grooves 101 of the plate A and the grooves 102 of the plate B.
• the grooves have a profile of an arc of a circle, of width w, and of height e.
• Figure 3 illustrates, schematically and in a non-limiting way, an arcuate profile of a groove according to a variant embodiment of the invention.
• the arc of a circle can be defined by the height e of the groove, by the radius r of the arc of a circle, as well as by the angle q> of opening of the arc of a circle.
• Figure 4 illustrates, schematically and in a non-limiting manner, an airplane wing profile with a groove according to an alternative embodiment of the invention.
• the airplane wing profile can be defined in particular by the height e of the groove, as well as by the width w of the groove.
• Figure 5 illustrates, schematically and in a non-limiting manner, a pair of plates according to a first embodiment of the invention.
• the pair of plates comprises a first plate A, and a second plate B.
• Plate A comprises a central panel A o
• plate B comprises a central panel B o (not shown).
• the central panels A o and B o are flat, parallel and spaced apart to form an internal volume V.
• the central panel A o comprises a plurality of rectilinear, parallel and projecting grooves 101 in the internal volume V.
• the central panel B o comprises a plurality of grooves (not shown) rectilinear, parallel and projecting into the internal volume V.
• the grooves of the second plate B can be, in accordance with the preferred embodiment, offset from the grooves 101 of the first plate A.
• the pair of plates (A, B) further comprises two first junction panels C and D.
• the junction panels C and D are formed of two portions of the plate A bent relative to the central panel A o .
• the folds of the junction panels C and D are directed towards the plate B.
• the junction panels C and D allow the assembly of the pair of plates A and B.
• the junction panels C and D are arranged on two opposite sides of the central panel A o .
• the junction panels C and D can belong to the plate A.
• the internal volume V is also limited by the junction panels C and D, so as to limit a channel in which a first fluid F1 can flow. 'flow out.
• Figure 6 illustrates, schematically and in a non-limiting manner, a pair of plates according to a second embodiment of the invention.
• the left part of the figure shows the two plates separately, and the right part of the figure shows the pair of plates.
• the pair of plates comprises a first plate A, and a second plate B.
• Plate A comprises a central panel A o
• plate B comprises a central panel B o .
• the central panels A o and B o are flat, parallel and spaced apart to form an internal volume V.
• the central panel A o comprises a plurality of rectilinear, parallel and projecting grooves 101 in the internal volume V.
• the central panel B o comprises a plurality of rectilinear grooves 102, parallel and projecting into the internal volume V.
• the central panel A o is delimited by four sides A 2 to A 5 .
• Side A 5 is connected to a first junction panel J A .
• the first junction panel J A comprises a first part A 5 and a second part A 6 .
• the first part A 5 is bent at an angle 5 with respect to the central panel A o .
• the second part A 6 is folded with respect to the first part A 5 , and is parallel to the plane A o .
• the second part A 6 is intended to be fixed to the plate B.
• the plate B in particular the junction panels, can be symmetrical with the plate A (with the exception of the grooves when they are offset according to the embodiment preferred), it can be deduced by reversal: it comprises a first junction panel J B in two parts B 5 and B 6 , and part B 6 is intended to be fixed to the plate A.
• FIG. 7 illustrates, schematically and in a non-limiting manner, a pair of plates according to a third embodiment of the invention.
• the plate A further comprises on the side A 4 a second junction panel K A .
• the second junction panel K A is perpendicular to the central panel A o .
• the side A 4 of the central panel A o is perpendicular to the side A 5 of the central panel A o on which the first junction panel J A is provided.
• the second junction panel K A extends opposite the internal volume between the plates, and therefore opposite the side of the projecting grooves.
• Plate B in particular the junction panels, can be symmetrical with plate A (except for the grooves when they are offset according to the preferred embodiment): it comprises a second junction panel K B s' extending opposite the protrusions of the grooves.
• Figure 8 illustrates, schematically and in a non-limiting manner, a pair of plates according to a fourth embodiment of the invention.
• the plates A and B comprise elements identical to those of the embodiment of FIG. 7. These elements identical to the embodiment of FIG. 7 are not described again.
• the second junction panel K A of plate A is in two parts A 7 , A 8 bent relative to each other. Part A 8 being parallel to the central panel A o , to allow attachment to plate B.
• part A 7 comprises a plate A 9 which is in the extension of part A 7 on the same side as the projecting grooves.
• Plate A 9 cooperating with the edges of the parts A 5 and A 6 of the first junction panel J A , so as to close the space which is created by the parts A 5 and A 6 of the first junction panel J A .
• Plate B in particular the junction panels, can be symmetrical with plate A (except for the grooves when they are offset according to the preferred embodiment): it comprises a second junction panel K B s' extending opposite the projections of the grooves, with a part B 9 identical to the part A 9 .
• the invention also relates to a stack of pairs of heat exchanger plates.
• a stack comprises at least two pairs of plates according to any one of the variants or combinations of variants described above. Note respectively first pair of plates and second pair of plates, two successive pairs of plates in the stack so as to differentiate them.
• the two pairs of plates may be identical, or may be a mirror image (i.e. symmetric) of each other.
• the first pair of plates and the second pair of plates are arranged parallel to each other and facing each other.
• the internal volume between the two plates forms a single channel to receive the flow of a first fluid. This is the internal volume including the protruding grooves.
• the volume between the two pairs of consecutive plates in the stack forms a single channel to receive the flow of a second fluid. This is the volume not including the protruding grooves, but the recessed grooves.
• the second junction panels can be used to connect two pairs of consecutive plates, and to maintain a distance between the two pairs of consecutive plates.
• the second junction panels delimit the channel for the flow of the second fluid.
• the direction of fluid flow is determined by the design of the plates and how they are connected via the junction panels.
• the channel for the second fluid may be substantially perpendicular to the channel for the first fluid.
• This implementation can in particular be carried out by means of second junction panels perpendicular to the first junction panels.
• the channel for the second fluid can be substantially parallel to the channel for the first fluid.
• the height between two pairs of plates can be identical to the height between two plates.
• the height between two pairs of plates can be different from the height between two plates.
• Figure 9 illustrates, schematically and in a non-limiting manner, a stack of pairs of plates according to one embodiment of the invention.
• Figure 9 is a three-dimensional view showing only a portion of the central panels of a stack of two pairs of plates.
• the stack comprises a first pair of plates comprising the plates Aa and Ba, and a second pair of plates comprising the plates Ab and Bb.
• the plates Aa and Ab comprise inclined grooves 101 (not parallel to an edge of the central panel of the plates ).
• the plates Ba and Bb include inclined grooves 102 (not parallel to an edge of the central panel of the plates).
• the grooves project into the internal volume Va between the plates Aa and Ba.
• the grooves project into the internal volume Vb between the plates Ab and Bb.
• the volume between the two pairs of plates, in this case between the plates Ab and Ba is denoted Z, this volume has no protrusion.
• a first fluid F1 flows within the volumes Va and Vb .
• a second fluid F2 flows within volume Z.
• the flows of the fluids F1 and F2 are cross current: the flows are perpendicular. Heat exchanges between the fluids F1 and F2 are carried out through the plates Ba and Ab.
• the plate heat exchanger comprises pairs of plates according to any one of the variants or combinations of variants described above, or a stack of pairs of plates according to any one of the variants or combinations of variants described above.
• the plate heat exchanger comprises a frame for mounting the pairs of plates or the stacking of the pairs of plates.
• the heat exchanger includes:
• the inlet and the outlet for the first fluid being connected to the channels for the flow of the first fluid.
• the inlet and the outlet for the second fluid being connected to the channels for the flow of the second fluid.
• a plate heat exchanger according to the invention can be used for fluids operating at a pressure ranging from total 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 plate heat exchanger can operate 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 perpendicularly l 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”). current exchanger” according to the Anglo-Saxon terminology).
• 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 in substantially the same direction.
• the invention can also be used for plate type heat exchangers operating according to other flow principles.
• the heat exchanger according to 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 a furnace and the fumes from the same furnace or similar, the hot stream coming from a NOx reduction system and the cold stream going to the same NOx reduction system.
• the first fluid can be air
• the second fluid can be the fumes.
• the heat exchanger can have an application in all fields of industry or energy production or in any analogous system.
• the invention relates to a method for manufacturing a stack of pairs of plates according to any one of the variants or combinations of variants described above, or a heat exchanger according to any one of the variants or combinations of variants described above.
• At least four plates are prepared, each plate comprising a central panel;
• each plate comprising a central panel;
• at least one groove is formed in the central panel of each plate, in particular by stamping, the groove possibly being inclined with respect to one side of the central panel;
• At least one groove is formed in the central panel of each plate, in particular by stamping, the groove possibly being inclined with respect to one side of the central panel;
• At least two pairs of plates are assembled, and, for each pair of plates, a first plate of said first half of said plates is arranged parallel to a second plate of said second half of said plates, so that the grooves are parallel l to each other and projecting into the internal volume between the plates, and optionally with an offset of each groove of the first plate relative to each groove of the second plate in a direction perpendicular to the grooves;
• the manufacturing method may comprise an additional step, in which, after the step of preparing the plates, the heat exchanger plates into two stacks (first half of plates and second half of plates), so as to prepare two different kinds of plates (first plate and second plate respectively).
• the plates of the first half of the plates are, except in special cases, different from the plates of the second half of the plates.
• the grooves made are, except in special cases, different between these plates.
• the grooves can be formed in the plates in such a way that the grooves of the plates of the second stack are offset by a regular pitch from the grooves of the plates of the first stack.
• the method may also comprise at least one of the following steps:
• At least one of the sides of the plates is folded to create at least one junction panel on each plate (embodiments of Figures 5 to 8),
• Each pair of plates is assembled by fixing the junction panels on the other plate of the pair of plates (embodiments of Figures 5 to 8),
• - AA2 a plate heat exchanger according to a second prior art, for which the plates comprise grooves inclined at 45° relative to the edge, and for which the grooves of the second plate are orthogonal to the grooves of the first plate (on the simplified figure in top view the grooves of the first plate are shown in continuous lines, and the grooves of the second plate are shown in dotted lines), this embodiment corresponds to that described in the patent application FR3003637, and
• INV a plate heat exchanger according to the invention, for which the plates comprise grooves inclined at 45° with respect to the edge, and for which the grooves of the second plate are parallel and offset with respect to the grooves of the first plate , the offset has a distance which corresponds to half of the regular spacing of the grooves (in the simplified figure in plan view the grooves of the first plate are represented by a solid line, and the grooves of the second plate are represented by lines dotted lines).
• the heat transfer is evaluated (Nusselt noted Nu which is an adimensional number used to characterize the type of heat transfer between a fluid and a wall) and the friction factor (from the English "friction factor” noted is a dimensionless number expressing the head loss) as a function of the Reynolds number (which is a dimensionless number that characterizes the type of flow, in particular the nature of its diet).
• the ratio is determined which represents the thermal performance of f 3 the heat exchange with respect to the pressure drops. A high value of such a ratio makes it possible to qualify the heat transfer with respect to the pressure drops; if two heat exchangers have the same pressure drop, but a different ratio, the one with the higher ratio will have better heat transfer, and may require a smaller heat exchange surface.
• Figure 1 1 represents the curves for the three configurations of the ratio — as a function of f 3 Reynolds number. It is noted that the invention INV makes it possible to have a higher ratio f 3 whatever the Reynolds number. It follows that the invention allows a reinforcement of the higher heat transfer for an identical pressure drop compared to the plate heat exchangers of the prior art. Consequently, the invention is more efficient in terms of heat transfer than the solutions of the prior art.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

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• 2021
  • 2021-10-25 FR FR2111317A patent/FR3128520B1/fr active Active
• 2022
  • 2022-10-10 EP EP22801760.4A patent/EP4423447A1/de active Pending
  • 2022-10-10 KR KR1020247013137A patent/KR20240095204A/ko active Pending
  • 2022-10-10 WO PCT/EP2022/078118 patent/WO2023072571A1/fr not_active Ceased
  • 2022-10-10 US US18/704,251 patent/US20240418456A1/en active Pending
  • 2022-10-10 CN CN202280071990.0A patent/CN118176401A/zh active Pending

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