Method for mounting or maintenance of a plate heat exchanger

Abstract

The method of mounting a plate heat exchanger as part of a maintenance operation of said exchanger, in which said plate heat exchanger is assembled according to an arrangement plan, sets of notches made in the peripheral edge of the plates allowing to control the conformity of the assembly to the arrangement plan.

Description

FIELD OF INVENTION

[0001] The present invention relates to plate heat exchangers. TECHNOLOGICAL BACKGROUND

[0002] Document FR 2 125 471 describes a plate heat exchanger. As shown, for example, in Figure 18 of this document, a plate heat exchanger comprises several identical or similar plates placed side by side. Such a plate heat exchanger also includes an inlet for a first fluid, an outlet for the first fluid, an inlet for a second fluid, and an outlet for the second fluid. The plate heat exchanger is arranged to allow the first and second fluids to flow between their respective inlets and outlets without mixing. To achieve this, holes are arranged in the plates to allow the fluid to flow through the main plane of the plate. A fluid can also flow from one hole to another between two adjacent plates. If two fluids on either side of a plate are at different temperatures, heat transfer occurs across the plate between these two fluids.

[0003] Gasketed plate heat exchangers were developed to address the need for improved heat exchange efficiency in industrial applications. Furthermore, the gaskets allow for easy disassembly for cleaning and maintenance, which is crucial in industrial settings where hygiene and efficiency are paramount.

[0004] These removable plate heat exchangers allow for complete maintenance by disassembling the unit, enabling individual plate servicing. Furthermore, if a single plate fails, it can be replaced with a new one, resulting in a more environmentally friendly solution compared to replacing the entire plate heat exchanger.

[0005] As fluid circuits become increasingly complex, the correct reassembly of the plate heat exchanger after maintenance is absolutely essential to optimize heat transfer. Indeed, if a single plate is reinstalled in an undesired position, and / or upside down, the resulting fluid circuit alteration can lead to undesired fluid mixing or local overpressure, potentially causing permanent damage to the plate heat exchanger. The invention thus aims to ensure the safe reassembly of a plate heat exchanger following maintenance.

[0006] In the field of welded plate heat exchangers, which do not meet the maintenance requirements mentioned above, WO 2010 / 116,459 describes the creation of protrusions on one lateral face of the peripheral edge of the plates. Once the plates are assembled, an optical inspection is carried out using an optical scanner before the plates are permanently welded.

[0007] US 2018 / 111,182 describes an automation of the manufacturing process for a plate heat exchanger. This automation involves optical barcode reading.

[0008] GB 1 131 124 is a 1968 document, which describes notches used to determine the correct orientation of the rectangular plate in the exchanger.

[0009] Thus, none of these documents mentions the problem of reassembling the plate heat exchanger as part of a maintenance operation, for the simple reason that these plate heat exchangers are not designed to be disassembled. SUMMARY OF THE INVENTION

[0010] Thus, the invention relates to a method for assembling a plate heat exchanger as part of a maintenance operation for said exchanger, in which, having a plurality of plates intended to be assembled in a demountable manner to form said plate heat exchanger, each of the plates comprising: a peripheral edge, a number of disjointed through holes each adapted to allow the circulation through the plate of a fluid to be cooled / heated, said number of holes being between zero and a non-zero integer, reliefs adapted to allow the flow of said fluid along a principal face of the plate when it faces an opposite principal face of another plate of the plate heat exchanger and is fixed thereto in a detachable manner with the interposition of at least one sealing gasket, said reliefs being arranged in a plurality of relief configurations, a set of notches made in the peripheral edge such that the set of notches is visible when the heat exchanger is assembled, said set of notches being representative of both the number and location of the holes and the relief configuration of the respective plate, The said plate heat exchanger is assembled according to an arrangement plan, the sets of notches allowing control of the conformity of the assembly to the arrangement plan.

[0011] Thanks to these provisions, it is possible to verify that the plate heat exchanger is correctly mounted or remounted after a maintenance or verification operation before being put back into service, ensuring its proper arrangement and exchange rate.

[0012] Depending on various aspects, it is possible to predict one and / or the other of the characteristics below taken alone or in combination.

[0013] According to one embodiment, said plates have a rectangular format, the number of through holes is between zero and four, and said through holes are arranged at the corners of the plate.

[0014] According to one design, the number of relief configurations is 2.

[0015] According to one embodiment, said set of notches is arranged in a location on the peripheral edge varying symmetrically with respect to a median axis of the plate.

[0016] According to one embodiment, said set of notches is a first set of notches, said location is a first location of the peripheral slice, and the plate includes a second set of notches made in the peripheral slice in a second location of the peripheral slice, symmetrical to the first location by rotation of 180° with respect to the axis normal to the plate, so that the second set of notches is visible when the heat exchanger is assembled, said second set of notches being representative of both the number and location of the holes and the relief configuration of the plate.

[0017] According to another aspect, the invention relates to a method of maintaining a plate heat exchanger comprising dismantling a plate heat exchanger, cleaning and / or replacing at least one plate, and this assembly method.

[0018] According to one embodiment, the maintenance process further includes the creation of said set of notches between disassembly and assembly.

[0019] According to one implementation, the maintenance process also includes checking the conformity of the assembly to the arrangement plan.

[0020] According to another aspect, the invention relates to use in such an assembly or maintenance method of at least one plate comprising: a peripheral slice, a number of disjointed through holes each adapted to allow the circulation through the plate of a fluid to be cooled / heated, said number of holes being between zero and a non-zero integer, reliefs adapted to allow the flow of said fluid along a main face of the plate when it faces an opposite main face of another plate of the plate heat exchanger and is fixed to it in a detachable manner with the interposition of at least one sealing gasket, said reliefs being arranged according to a plurality of relief configurations, a set of notches made in the peripheral slice so that the set of notches is visible when the heat exchanger is assembled, said set of notches being representative of both the number and location of the holes and the relief configuration of the respective plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the invention will be described below with reference to the drawings, briefly described below: [ Fig. 1 ] is a perspective view that partially represents a plate heat exchanger. Fig. 2 ] is a front view of a first principal face of a plate of the plate heat exchanger of the figure 1 . [ Fig. 3 ] is a front view of part of a first main face of another type of plate in a plate heat exchanger. Fig. 4 [ ] is a schematic diagram showing different examples of plates. [ Fig. 5 ] is a front view of a portion of a plate. Fig. 6 ] is a view similar to the figure 5 for another method of plate construction. Fig. 7 ] is a front view of a plate according to a given embodiment. Fig. 8 ] is an exploded side perspective view showing several juxtaposed plates. Fig. 9[ ] is a schematic side view of a plate heat exchanger according to a first arrangement plane. Fig. 10 ] is a schematic side view for a plate heat exchanger according to a second arrangement plane.

[0022] In the drawings, identical references designate identical or similar objects. DETAILED DESCRIPTION

[0023] There figure 1 represents a plate heat exchanger 1 according to an example of an embodiment.

[0024] The plate heat exchanger 1 comprises a plurality of plates 2 arranged juxtaposed to one another along a longitudinal axis X. The plates 2 will be described in more detail below.

[0025] As also visible on the figure 1The plate heat exchanger 1 may further include end plates 8, between which the plates 2 are assembled. The plate heat exchanger 1 may also include one or more intermediate plates 9 similar to the end plates 8. The end plates 8 and intermediate plates 9 are thicker than the plates 2 and are used for securing the plate heat exchanger. The end plates 8 and intermediate plates 9 do not have the characteristics of the plates 2 used for heat transfer. A fastening system 10 is used to hold the plates 2, 8, and 9 together. The fastening system 10 includes, for example, a set of rods 11 bolted to the end plates 8 and / or intermediate plates 9. These rods 11 do not interact directly with the plates 2, which are held in compression between the end plates 8 and / or intermediate plates 9 due to the clamping force applied to the end plates 8 and intermediate plates 9.

[0026] The plate heat exchanger 1 also includes an inlet 3 for a first fluid and an outlet 4 for the first fluid. A first fluid is intended to flow through the plate heat exchanger from the inlet 3 to the outlet 4.

[0027] The plate heat exchanger 1 also includes an inlet 5 for a second fluid and an outlet 6 for the second fluid. A second fluid is intended to flow through the plate heat exchanger from the inlet 5 to the outlet 6.

[0028] In the example shown, the inlet 3 and outlet 4 for the first fluid, and the inlet 5 and outlet 6 for the second fluid are arranged on the same face 7 of the plate exchanger.

[0029] The end plates 8 and intermediate plates 9 include the openings 12 necessary for the passage of the first and second fluids through them. In the embodiment shown, one end plate 8 includes four such openings 12. The other end plate may then have no openings. As shown, it may not even be a plate, but simply a support for the plates 2.

[0030] The end plates 8 and intermediate plates 9 are not involved in the invention.

[0031] There figure 2 schematically presents a plate 2 that can be used in the context of the invention.

[0032] Plate 2 is a thin plate, produced by shaping, notably by pressing or stamping a die. The die is made of a material with a high heat transfer coefficient and high mechanical strength. It is typically a metal plate, for example, sheet metal. The plate may have undergone various treatments, for example, an anti-corrosion treatment.

[0033] Therefore, plate 2 has a dimension much smaller than its other two dimensions. This dimension is called "thickness". The plates 2 are arranged in the exchanger 1 so that their thickness is oriented along its longitudinal X direction.

[0034] Plate 2 comprises a first principal face 15 and a second principal face 16 opposite the first principal face 15. The second principal face 16 has a geometry representing the negative of the first principal face 15. To specify, with respect to a reference plane YZ of plate 2, normal to the thickness direction, if the first principal face 15 has a protrusion, the second principal face 16 has a hollow, and vice versa.

[0035] Thus, the first and second main faces 15 and 16 of the same plate 2 are not interchangeable.

[0036] To clarify, the face of plate 2 comprising a recessed groove 17 adapted to receive the sealing gasket is called the "first main face 15", as will be shown in more detail below.

[0037] Viewed in the plane normal to the thickness direction, plate 2 has a peripheral perimeter. In one embodiment, the peripheral perimeter is polygonal. In the embodiment shown, the peripheral perimeter is rectangular. Specifically, the peripheral perimeter is rectangular but not square, meaning that, along the two principal directions of plate 2, its length L is longer than its width l. "Longer" means that a person skilled in the art can identify that the plate is rectangular but not square, and that one of its principal dimensions is greater than the other. For clarity, the Y-axis is used to denote the width, and the Z-axis the length, for a plate mounted in the plate heat exchanger of the figure 1 .

[0038] Plate 2 thus has a number of corners 13, arranged at the intersections of the edges, in this case four corners for a rectangular plate 2.

[0039] By "rectangular," we mean that the overall shape of the plate is generally rectangular, although it may deviate from a rectangular shape locally, such as having rounded corners as shown. The same applies to the definition of "polygonal."

[0040] Plate 2 has four through holes 14 that are not joined. The holes are located, in particular, at the four corners 13.

[0041] The first main face 15 has a continuous peripheral groove 17 (NB: on the figure 2 , a sealing gasket is arranged in this groove 17). The continuous peripheral groove 17 is closed and defines on one side an interior 18 of the plate and an exterior 19 of the plate, on either side of the peripheral groove 17. The four holes 14 are in particular arranged in the interior 18.

[0042] The first main face 15 also has an intermediate groove 20 (NB: on the figure 2 (Top left, the sealing gasket is positioned in this intermediate groove 20). The intermediate groove 20 extends between two ends 20a and 20b, both opening into the peripheral groove 17. The portion of the peripheral groove 17 extending between these two ends 20a and 20b and the intermediate groove 20 together form a groove that surrounds a first hole 14. The first main face 15 has such an intermediate groove 20 for each hole (NB: on the figure 2 , top right, no sealing gasket is placed in this intermediate groove 20).

[0043] The first main face 15 also has, in the interior 18, a relief 21 influencing the flow of the fluid between this first main face 15 and the second main face 16 of the plate 2 facing this first main face 15.

[0044] The relief 21 may include in particular hollows and bumps relative to the reference plane of plate 2. These bumps may in particular be of such an extent that they are in contact with the second main face 16 of plate 2 facing this first main face 15 when the exchanger is assembled, or of a lesser extent, so that they may allow a flow of fluid between these two plates.

[0045] There are several topographic configurations 21 depending on the plates considered. A topographic configuration will influence the fluid flow velocity along plate 2. Thus, for the same fluid (subjected to the same flow stress), depending on the topographic configuration, it will flow more or less quickly along plate 2. This results in a variable transit time along the plate, and consequently a variable heat transfer time with an adjacent fluid (with an interposed plate), and therefore a variable amount of energy transferred.

[0046] The relief 21 comprises a chevron zone 22, as well as a transition zone 23 located between the through holes 14 and the chevron zone 22. In particular, the relief 21 may be symmetrical with respect to the longitudinal axis Z of the plate (an axis extending along the length of the plate 2). The chevron zone may comprise alternating parallel grooves and ribs inclined with respect to the longitudinal axis Z of the plate. In this text, the term "rib" is used to designate a boss, a projection, or a protrusion, while the term "groove" is used to designate a recess or indentation.

[0047] As discussed above, the geometry of the second main face 16 of plate 2 can be determined, as it corresponds to the negative of the first main face 15.

[0048] As depicted on the figure 3A plate 2' may have the same general rectangular shape and dimensions as plate 2. The configuration of the holes 14, the transition zone 23, and the grooves 17 and 20 is identical to that of plate 2. Plate 2' differs from plate 2 by the configuration of the relief 21'. The difference between the reliefs 21 and 21' of two plates 2 and 2' is evident to a person skilled in the art, who observes different flow and heat transfer characteristics of the fluid flowing along the two plates.

[0049] For example, plate 2' has the same arrangement of rafter zone 22' and transition zone 23 as plate 2, but the slope of the rafters 22' of plate 2' differs from the slope of the rafters 22 of plate 2.

[0050] Regardless of the configuration of reliefs 21, 21', the plates 2 may differ in the number and location of the perforations 14.

[0051] More specifically, if a plate includes holes, they are located in the same positions as the holes in plate 2 of the figure 2 , in order to allow a continuous flow of fluid through different plates.

[0052] We use the reference 2 abcd, where a, b, c, and d are Boolean values, to designate a plate 2 in which the letter "a" designates the top left corner, the letter "b" the top right corner, the letter "c" the bottom right corner, and the letter "d" the bottom left corner, in the intended orientation of the plate, and where the Boolean value is respectively "1" or "0" depending on the presence or absence of a hole. Thus, the plate of the figure 2 may be designated by the reference 2 1111.

[0053] As seen on the figure 4 The following plates can be used in the context of the invention: 20000: No holes, 21000: One hole in the top left, 20100: One hole in the top right, 20010: One hole in the bottom right, 20001: One hole in the bottom left, 21100: Only the two top holes, 20110: Only the two right holes, 20011: Only the two bottom holes, 21001: Only the two left holes, 20101: Only the top right and bottom left holes, 21010: Only the top left and bottom right holes, 21110: All holes except the bottom left, 21101: All holes except the bottom right, 24011: All holes except the top right, 20111 : All holes except in the top left corner.

[0054] Thus, for a maximum of four holes, there are 16 different hole configurations, which can be coded on four bits.

[0055] To this end, physical modifications are made to corners "a" and "d," corresponding to the upper left and lower right corners of plate 2, in order to incorporate a material not intended to stiffen the assembly under pressure. This material can thus be modified to allow for easier visual identification of plate 2, without compromising its integrity or function.

[0056] As seen on the figure 5 Plate 2 has a code 24. The code 24 is permanent and visible when the plate heat exchanger is mounted. Each code includes at least one notch. The code 24 thus includes one or more notches 25 made in the edge 26 of plate 2, particularly in the outer zone 19 of plate 2, where fluids do not flow when a sealing gasket is placed in the peripheral groove 17.

[0057] There is a region 27, or location, for making the notches 25, and the same region is used for all the plates.

[0058] According to an example, region 27 is not positioned symmetrically by rotation around the Y axis. Thus, if plate 2 is mounted incorrectly following a 180° rotation about the Y axis, region 27 of this plate will not be positioned in alignment with regions 27 of the other plates, and this mounting error will be immediately identified.

[0059] For example, region 27 is made in a corner 13 of the plate.

[0060] The coding 24 codes both for the configuration of the reliefs 21 and for the number and arrangement of the perforations 14.

[0061] For example, 24-bit encoding includes four notches corresponding to the four bits "a", "b", "c", "d" described previously.

[0062] In addition, the coding 24 includes one or more notches 30 representing the relief configuration 21, depending on the number of notches needed to code the number of relief configurations 21.

[0063] Where applicable, the notches relating to the relief configuration 21 have different shapes depending on the relief configuration 21.

[0064] Thus, in the example of the figure 5 , a first notch, with a "W" shape designates a relief 21 according to a first configuration, and the following four notches mean: a = 1, b = 1, c = 1, d = 1, i.e. four holes at the top left, top right, bottom right and bottom left.

[0065] Thus, in the example of the figure 6 , the single notch 30, with a "U" shape designates a relief 21 according to a second configuration.

[0066] For the sake of completeness, it should be noted that plate 2 may have one or more non-coding notches 29 (visible for example on the figure 2 ), in its exterior 19, for example used for fixing the plates together.

[0067] According to one embodiment, a plate 2 can be identified by its so-called "Right" side or its so-called "Left" side thanks to a notch system. The "Left" side of the plate is designated by a large "U" shaped notch, while the "Right" side of the plate is designated by a large "V" shaped notch. The figure 6 The diagram above shows a large "U" shaped notch 30, designating the "Left" side of a plate 2. It is also understood that a large "V" shaped notch for the right side is also provided, although not shown in the figures.

[0068] According to one embodiment, the plate 2 can also be distinguished by its fluid velocity, thus characterizing whether the plate is considered "fast" or "slow". A fast plate is defined by its ability to allow a significant flow of fluid through the multiple perforations and is identified by two notches 30 in a large "U" shape or two notches 30 in a large "V" shape. Conversely, a slow plate is designed to restrict the fluid flow, which reduces its velocity through the plate, and is identified by a single notch, either in a large "U" or a large "V" shape. figures 5 and 6 illustrate successively a fast plate and a slow plate.

[0069] According to one embodiment, the coding of plate 2 is completed by adding 25 small "V" notches. This coding is performed after the initial marking with the large "V" and large "U" notches, using the latter as a reference. The coding is then continued with a maximum of four small "V" notches, each 25 small "V" notch representing a letter in the order a, b, c, d. Preferably, the small notches 25 are equidistant, and the first is preferably located 11 mm from the starting reference. This coding allows for quick visual identification of plate 2 without requiring complete disassembly, thus facilitating assembly checks.

[0070] According to an example of implementation, as shown on the figure 7 , plate 2 comprises two regions 27 in which notches 25 are arranged.

[0071] The two regions 27 are symmetrical to each other by rotation of 180° around the longitudinal axis X normal to the plate.

[0072] Thus, depending on whether plate 2 is mounted according to the orientation shown on the figure 2 , or rotated 180° with respect to the longitudinal axis X of the latter, a region 27 is aligned with the regions 27 of the other plates 2.

[0073] However, since the arrangement of the holes in the plate is not necessarily identical after this 180° rotation, the codes that appear in the two regions 27 may be different.

[0074] For example, if the encoding in a first region 27 comprises three notches 25 which mean: a = 1, b = 1, c = 1, d = 0, i.e., three holes at the top left, top right, and bottom right, the plate, after rotation of 180° around the longitudinal axis X, comprises three holes at the top left, bottom left, and bottom right, which corresponds to a code a = 1, b = 0, c = 1, d = 1. Thus, in the second region 27, as shown on the figure 7 The coding includes a 25 notch, a solid one, then two 25 notches.

[0075] An example of the implementation of the invention is described below.

[0076] A plurality of plates 2 are manufactured, each plate containing a code as described previously. Where applicable, the code is created in the plate during the same manufacturing step as the formation of the holes 14 and the reliefs 21.

[0077] A plate heat exchanger 1 is formed from the plates according to an arrangement plan, after installing suitable sealing gaskets on the plates 2. Depending on the desired flow at the plate 2, a sealing gasket is installed which extends at least in the entire peripheral groove 17, and may also extend into one or more intermediate grooves 20. During assembly, the gasket in question is compressed on the second main face of the plate facing the main face of the plate bearing the gasket.

[0078] During operation, a first fluid, typically a liquid, is circulated through the plate heat exchanger from inlet 3 to outlet 4. This first fluid could be, for example, a food, cosmetic, or pharmaceutical fluid, or another type. At inlet 3, it has an inlet temperature T3. At outlet 4, it has an outlet temperature T4. T3 is very different from T4. For example, the difference between T3 and T4 could be at least 10°C, at least 20°C, at least 30°C, or even more. A second fluid, typically a liquid, is then circulated through the plate heat exchanger from inlet 5 to outlet 6. This second fluid could be, for example, water, steam, or air. At inlet 5, it has an inlet temperature T5. At outlet 6, it has an outlet temperature T6. The fluids circulate in the plate heat exchanger under the effect of an unrepresented circulation system, such as a pump or other, according to the paths drawn internally in the plate heat exchanger.Specifically, if a plate 2 includes a bore 14 hydraulically connected to the inlet 3, the fluid can flow through the plate 2 at this bore. If, at the bore in question, the intermediate groove 20 is not fitted with a seal, the fluid can flow along a first main face of the plate in question, as well as along the second main face of the plate upstream along the path of the first fluid, and heat transfer occurs through these plates, provided that, on the other side of them, there is a fluid at a different temperature. For example, the first fluid is heated by heat transfer from the second fluid, which is hotter than the first, and is present on the other side of one of these two plates. Alternatively, the first fluid is cooled by heat transfer to the second fluid, which is colder than the first, and is present on the other side of one of these two plates.The first fluid can flow to one or more other holes 14 in the plate, not sealed by a gasket in an adjacent intermediate groove 20, or in the upstream plate, from which it continues its flow towards the outlet 4.

[0079] There figure 9 This diagram represents a schematic representation of an early example of a plate heat exchanger. The bores are shown one above the other for ease of reading, even though, within the exchanger itself, the two bores are located at the same vertical level. The fluid marked "f" represents the cold fluid, and the fluid marked "c" represents the hot fluid.

[0080] There Figure 10This represents a schematic diagram of a second example of a plate heat exchanger. As can be seen from the diagram, the configuration is very different from that of the first example. For example, in this configuration, the two fluids each flow from one end plate to the other, and in generally opposite directions of flow.

[0081] These two examples are just two simplified examples, showing a very small number of plates, of how different arrangement plans can be.

[0082] For various reasons, the plate heat exchanger undergoes maintenance. The fluid flow is stopped. The plate heat exchanger is disassembled. Using appropriate tools, the codes described above are applied to the plates of the plate heat exchanger. The plates are cleaned. If necessary, a plate deemed worn is replaced with a corresponding new plate. The new plate is also coded. The heat exchanger is reassembled. The codes allow verification that the heat exchanger has been reassembled according to its arrangement plan. Then, the plate heat exchanger is put back into service. Thus, the invention is applicable to plate heat exchangers already installed and in operation, even if they are not equipped with coded plates.

[0083] Where appropriate, the maintenance procedure described above can be carried out for a plate heat exchanger whose plates already include codings, depending on whether the codings were applied to the plates during their manufacture, or whether they were added during a previous maintenance operation.

[0084] It is also possible to check the arrangement of the exchanger without having to dismantle or open it, thus limiting the risk of damaging the seals between the plates and protecting against any contamination.

[0085] Alternatively, the inlet 3 and outlet 4 of the first fluid can be arranged on different faces of the plate heat exchanger.

[0086] Alternatively, the inlet 5 and outlet 6 of the second fluid can be arranged on different faces of the plate heat exchanger.

[0087] Alternatively, the inlet 3 of the first fluid and the inlet 5 of the second fluid can be arranged on different faces of the plate heat exchanger.

[0088] Alternatively, there are more than four maximum holes per plate, and the encoding includes a number of bits corresponding to the maximum number of holes. LIST OF REFERENCE SIGNS

[0089] 1: Plate heat exchanger 2: Plates 3: Inlet for first fluid 4: Outlet for first fluid 5: Inlet for second fluid 6: Outlet for second fluid 7: Face 8: End plates 9: Intermediate plate 10: Fastening system 11: Rods 12: Openings 13: Corners 14: Through holes 15: First main face 16: Second main face 17: Groove 18: Interior 19: Exterior 20: Intermediate groove 20a, 20b: Ends 21: Relief 22: Chevrons 23: Transition zone 24: Coding 25: Notch 26: Edge 27: Location 28: Gasket 29: Non-coding notch 30: Notch coding relief configuration

Claims

1. A method for assembling a plate heat exchanger as part of a maintenance operation for said exchanger, wherein, having a plurality of plates (2, 2') intended to be assembled in a demountable manner to form said plate heat exchanger, each of the plates comprising: - a peripheral edge (26), - a number of through holes (14) separated, each adapted to allow the circulation through the plate of a fluid to be cooled / heated, said number of holes being between zero and a non-zero integer, - reliefs (21) adapted to allow the flow of said fluid along a principal face (15) of the plate when the latter faces an opposite principal face (16) of another plate of the plate heat exchanger and is fixed thereto in a demountable manner with the interposition of at least one sealing gasket (28), said reliefs being arranged according to one of a plurality of relief configurations,- a set of notches (25) made in the peripheral edge such that the set of notches is visible when the heat exchanger is assembled, said set of notches being representative of both the number and location of the holes and the relief configuration of the respective plate, said plate heat exchanger is assembled according to an arrangement plan, the sets of notches allowing the conformity of the assembly to the arrangement plan to be checked.

2. Assembly method according to claim 1, wherein said plates (2, 2') have a rectangular format, the number of through holes is between zero and four, and said through holes are arranged at the corners of the plate.

3. Assembly method according to claim 1 or 2, wherein the number of relief configurations (21) is 2.

4. Assembly method according to any one of claims 1 to 3, wherein said set of notches (25) is arranged in a location (27) of the peripheral edge varying symmetrically with respect to a median axis of the plate.

5. Assembly method according to any one of claims 1 to 4, wherein said set of notches (25) is a first set of notches, said location (27) is a first location of the peripheral slice, and wherein the plate comprises a second set of notches made in the peripheral slice in a second location (27) of the peripheral slice, symmetrical to the first location (27) by rotation of 180° with respect to the axis normal to the plate, such that the second set of notches is visible when the heat exchanger is assembled, said second set of notches being representative of both the number and location of the holes and the relief configuration of the plate.

6. Method of maintaining a plate heat exchanger comprising dismantling a plate heat exchanger, cleaning and / or replacing at least one plate, and the method of assembly according to any one of claims 1 to 5.

7. Maintenance method according to claim 6, further comprising making said set of notches between disassembly and assembly.

8. Maintenance method according to claim 6 or 7, further comprising checking the conformity of the assembly to the arrangement plan.

9. Use in an assembly method according to any one of claims 1 to 5 or a maintenance method according to any one of claims 6 to 8 of at least one plate comprising: - a peripheral edge, - a number of through holes (14) separated each adapted to allow the circulation through the plate of a fluid to be cooled / heated, said number of holes being between zero and a non-zero integer, - reliefs (21) adapted to allow the flow of said fluid along a principal face of the plate when the latter faces an opposite principal face of another plate of the plate heat exchanger and is fixed thereto in a detachable manner with the interposition of at least one sealing gasket, said reliefs being arranged in one of a plurality of relief configurations,- a set of notches (25) made in the peripheral edge such that the set of notches is visible when the heat exchanger is assembled, said set of notches being representative of both the number and location of the holes and the relief configuration of the respective plate.

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