Plate for a heat exchanger and heat exchanger having such a plate

Abstract

A plate (1) for a heat exchanger (30), the plate comprising a plurality of cells (10), each cell (10) comprising a first face (11) and a second face (12) opposite the first face (11), the first face (11) and the second face (12) having a plurality of spacers (14, 16) arranged to create mutually perpendicular flow directions between the first face (11) and the second face (12). The spacers (14, 16) differ in number and / or shape and / or size between the first face (11) and the second face (12).

Description

Technical Field

[0001] This invention relates to a plate for a heat exchanger.

[0002] The present invention also relates to a heat exchanger having such a plate. Background Technology

[0003] Today, various types of heat exchangers are used to regulate the air in enclosed environments such as offices, server rooms, or data centers.

[0004] Among these heat exchangers are plate heat exchangers.

[0005] Plate heat exchangers have a series of parallel plates, which are usually made of metal.

[0006] These plates, in pairs, define alternating passage chambers for hot fluids or for cold fluids (hot air and cold air).

[0007] In this specification, the term "hot fluid" refers to a fluid having a higher enthalpy than a fluid defined as "cold fluid".

[0008] Similarly, in this specification, the term "cold fluid" refers to a fluid having a lower enthalpy than a fluid defined as "hot fluid".

[0009] Therefore, one side of each plate is in contact with the cold fluid, and the other side is in contact with the hot fluid.

[0010] Typically, the plate has a corrugated surface.

[0011] The surface ripples allow for increased heat exchange area and turbulence.

[0012] These plates are then separated by spacers adapted to maintain them at a constant and predetermined distance.

[0013] These spacers can:

[0014] - Separate from the board, and made of, for example, rubber or other plastic materials.

[0015] - It is an integral part of the board, consisting of protrusions formed directly on the board.

[0016] Panels with integrated spacers are simpler, faster, and cheaper to manufacture.

[0017] In fact, spacers are made during the molding process of the plate, or at most during a subsequent molding process; they do not need to be made separately and then attached to the plate.

[0018] For example, Heatex AB's EP2645039B1 includes instructions for providing a plate with multiple protrusions that form spacers, which are integrally molded with the plate itself.

[0019] This known technique has many drawbacks if a material with a low Young's modulus and a high pressure differential between the two surfaces is used.

[0020] The plate taught in EP2645039B1 is preferably made of aluminum, stainless steel or plastic material and has protrusions that form a series of channels.

[0021] Each side of the board has parallel channels, and the arrangement of the channels on one side is perpendicular to the arrangement of the channels on the other side of the board.

[0022] During use, one side of the plate is in contact with the hot fluid, while the other side is in contact with the cold fluid.

[0023] To reduce the risk of hot fluid being contaminated by cold fluid and to increase the enthalpy on the hot side, a fan is placed upstream of the hot fluid side and downstream of the cold fluid side.

[0024] This creates a strong pressure difference between the two sides of the exchanger: the cold side is always in a partial vacuum state, while the hot side is always under pressure.

[0025] As a result, the plate deforms, and thus its geometry changes, affecting the normal outflow of the cold fluid, with the flow resistance increasing uncontrollably.

[0026] This drawback is most pronounced for sheets made of plastic or other materials with low Young's modulus.

[0027] In this specification, the term "low Young's modulus" refers to the order of thousands of MPa. Summary of the Invention

[0028] The object of the present invention is to provide a plate for a heat exchanger and an exchanger having such a plate, which improves upon the known technology in one or more of the above-mentioned aspects.

[0029] Within this purpose, one objective of the present invention is to provide a plate for a heat exchanger, wherein the pressure difference between the hot and cold sides does not cause deformation and / or slight deformation, even if the plate is made of a material with a low Young's modulus.

[0030] Another object of the present invention is to provide a plate for a heat exchanger made of a material having a low Young's modulus, which optimizes heat exchange characteristics and flow resistance.

[0031] Another object of the present invention is to provide a switch having a board capable of achieving the above-mentioned object.

[0032] Another object of the present invention is to overcome the disadvantages of the prior art in a manner that replaces any existing solutions.

[0033] Another object of the present invention is to provide a plate for a heat exchanger and an exchanger having such a plate, which is highly reliable, easy to implement and low in cost.

[0034] This objective, as will become more apparent below, and these and other objectives are achieved by a plate for a heat exchanger comprising a plurality of cells, each cell comprising a first surface and a second surface opposite to the first surface, the first surface and the second surface having a plurality of spacers arranged to create mutually perpendicular flow directions between the first surface and the second surface, the plate being characterized in that the spacers differ in number and / or shape and / or size between the first surface and the second surface.

[0035] This objective, as well as these and other objectives, will become more apparent below and can also be achieved by a plate heat exchanger, characterized in that the plate heat exchanger comprises multiple plates, each of which is a plate as described above. Attached Figure Description

[0036] Other features and advantages of the invention will become more apparent from the following detailed description of preferred, but not exclusive, embodiments of the board for a switch according to the invention, which are illustrated by non-limiting examples in the accompanying drawings, in which:

[0037] - Figure 1 This is an overall perspective view of the plate according to the present invention;

[0038] - Figure 1a yes Figure 1 A perspective view of the first side of a portion of the plate;

[0039] - Figure 1b yes Figure 1a A perspective view of the second side, opposite to the aforementioned side;

[0040] - Figure 2 This is an overall perspective view of the exchanger according to the present invention;

[0041] - Figure 3 yes Figure 2 An exploded view of a portion of the switch;

[0042] - Figure 4 This is a cross-sectional side view of a portion of the exchanger according to the present invention;

[0043] - Figure 5 and Figure 6 This is a perspective view of two different sides of a portion of a heat exchanger according to the present invention;

[0044] - Figure 7 , Figure 8 and Figure 9 Schematic illustration along Figure 1 The distribution of load and curvature of a section of a plate;

[0045] - Figure 10 and Figure 11 The cross-sections of two types of beams are shown;

[0046] - Figure 12 The finite element simulation results of the tension distribution of the plate according to the present invention during operation are shown graphically.

[0047] - Figure 13 The finite element simulation results of the deformation of the plate according to the invention during operation are shown graphically. Detailed Implementation

[0048] Referring to the accompanying drawings, the plates for heat exchangers according to the present invention are generally indicated by reference numeral 1.

[0049] This board 1 includes multiple cells 10.

[0050] In particular, to make the details of board 1 clearly visible, Figure 1a and Figure 1b Cell 10 of plate 1 is shown, when the cell is repeated in the vertical and horizontal directions to form plate 1 for heat exchanger 30.

[0051] The cell 10 has a quadrilateral outline, preferably a square, and includes:

[0052] - Page 11, as shown Figure 1a As shown, the first surface is adapted to contact with cold fluid.

[0053] - Page 12, as shown Figure 1b As shown, the second surface is located on the opposite side of the first surface 11 and is adapted to contact with a hot fluid.

[0054] Cell 10 may have, for example, an edge between 50mm and 100mm, while the entire plate 1 may have, for example, an edge between 300mm and 1300mm.

[0055] Each face 11 and 12 of cell 10 has a corrugated pattern.

[0056] Plate 1 is made of a material with a low Young's modulus, such as plastic, PVC, polypropylene, or PET.

[0057] The table below lists the possible materials for manufacturing plate 1 and their corresponding Young's modulus.

[0058] Material Young's modulus (MPa) Polypropylene (PP) 1300–1800 Polyethylene (PET) 2800–3100 Polyvinyl chloride (PVC) 1500–3000

[0059] Such a plate 1 is made by molding in a single molding operation.

[0060] In particular, the ripples on face 11 of cell 10 are opposite to the ripples on face 12 of the second cell.

[0061] The above sentence means that the concave surface on the first surface 11 corresponds to the convex surface on the second surface 12, and vice versa.

[0062] This corrugation is suitable for increasing turbulence on the contact surface and in the fluid in contact with it, thereby improving heat exchange between hot and cold fluids.

[0063] Each face 11, 12 has multiple spacers 14, 16, and the face of each spacer is perpendicular to the surface of the corresponding face 11, 12.

[0064] Spacers 14 and 16 are arranged to create mutually perpendicular flow directions on two surfaces 11 and 12.

[0065] These spacers 14 and 16 are integrally formed with the rest of cell 10 and the rest of plate 1 during the molding of plate 1.

[0066] At each spacer 14 on the first surface 11, there is a complementary cavity / formed portion 17 on the second surface 12; and at each spacer 16 on the second surface 12, there is a complementary cavity / formed portion 18 on the first surface 11.

[0067] A particular feature of the invention is that such spacers 14, 16 differ in number and / or shape and / or size between the first surface 11 and the second surface 12.

[0068] In particular, the spacers 14 on the first surface 11 are more numerous and larger than the spacers 16 on the second surface 12.

[0069] With regard to the first axis X of cell 10, which is essentially centered and perpendicular to the direction of the corrugations, such a first surface 11 comprises two parts:

[0070] - Part 13a,

[0071] - Part 2, 13b.

[0072] Similarly, the second side 12 consists of two parts:

[0073] - Part 3, 15a, corresponds to and is the opposite of Part 1, 13a.

[0074] - Part 4, 15b, which corresponds to and is the opposite of Part 2, 13b.

[0075] The first surface 11 has a longitudinal first protrusion 19 extending along the first axis X, from which two first spacers 20a and 20b protrude.

[0076] The first protrusion 19 has a height of 2 mm to 4 mm, a length equivalent to the dimension of cell 10 along the first axis X, and a width of 8 mm to 12 mm.

[0077] In this instruction manual:

[0078] - The term "height" refers to the dimension in the direction perpendicular to the arrangement plane of cell 10 and the arrangement plane of plate 1.

[0079] - The term "length" refers to the dimension along the extension axis of the corresponding protrusion or partition, perpendicular to the height direction.

[0080] - The term "width" refers to the dimension perpendicular to the height and length.

[0081] The two first spacers 20a and 20b have, for example, a height of 3 mm to 6 mm, a length of 15 mm to 30 mm, and a width of 5 mm to 12 mm.

[0082] The two first spacers 20a and 20b are substantially mirror-symmetric with respect to a plane of symmetry of a second axis Y that is perpendicular to the first axis X and passes through cell 10, the second axis being substantially centered and parallel to the direction of the corrugations.

[0083] The first surface 11 has two longitudinal end protrusions 21a and 21b extending parallel to the first axis X, each longitudinal end protrusion being located at the peripheral edge of the cell 10:

[0084] -Second protrusion 21a,

[0085] - Third protrusion 21b.

[0086] These two longitudinal end protrusions 21a and 21b have, for example, a height of 2 mm to 4 mm, a length equivalent to the size of cell 10, and a width of 8 mm to 12 mm.

[0087] Two second spacers 22a and 22b protrude from the second protrusion 21a and are substantially mirror-symmetrical with respect to a plane of symmetry that is perpendicular to the first axis X and passes through the second axis Y.

[0088] These two second spacers 22a and 22b have, for example, a height of 3 mm to 6 mm, a length of 15 mm to 30 mm, and a width of 5 mm to 12 mm.

[0089] Similarly, two third spacers 23a, 23b protrude from the third protrusion 21b and are substantially mirror-symmetrical with respect to a plane of symmetry that is symmetrical with respect to the first axis X and passes through the second axis Y.

[0090] These two third spacers 23a and 23b have, for example, a height of 3 mm to 6 mm, a length of 15 mm to 30 mm, and a width of 5 mm to 12 mm.

[0091] The first part 13a has two fourth protrusions 24a, 24b extending along a substantially central axis parallel to the first axis X.

[0092] These two longitudinal fourth protrusions 24a and 24b have, for example, a height of 1 mm to 3 mm, a length of 20 mm to 30 mm, and a width of 3 mm to 8 mm.

[0093] The fourth spacers 25a and 25b extend from each fourth protrusion 24a and 24b at the corresponding peripheral edge of each cell 10 parallel to the second axis Y.

[0094] Each fourth spacer 25a, 25b has, for example, a height of 3 mm to 6 mm, a length of 10 mm to 20 mm, and a width of 5 mm to 15 mm.

[0095] The second part 13b has a longitudinal fifth protrusion 26 extending along a substantially central axis parallel to the first axis X.

[0096] The fifth protrusion 26 has, for example, a height of 1 mm to 3 mm, a length of 20 mm to 30 mm, and a width of 3 mm to 8 mm.

[0097] The fifth spacer 27 protrudes from the fifth protrusion 26 parallel to the first axis X and the second axis Y.

[0098] The fifth spacer 27 has, for example, a height of 3 mm to 6 mm, a length of 10 mm to 20 mm, and a width of 5 mm to 15 mm.

[0099] The third part 15a has a sixth spacer 28 extending along the second axis Y.

[0100] The sixth spacer 28 has, for example, a height of 3 mm to 8 mm, a length of 15 mm to 30 mm, and a width of 5 mm to 15 mm.

[0101] Part 4, 15b, has two seventh spacers, 29a and 29b, each of which is located at the peripheral edge of cell 10 parallel to the second axis Y.

[0102] These seventh spacers 29a, 29b, for example, have a height of 3 mm to 6 mm, a length of 15 mm to 30 mm, and a width of 5 mm to 15 mm.

[0103] Protrusions 19, 21a, 21b, 24a, 24b, and 26 are integrally formed with cell 10 and the rest of plate 1 during the molding process of plate 1, and these protrusions define channels through which cold fluid flows in the configuration to be used.

[0104] These protrusions 19, 21a, 21b, 24a, 24b, 26 and these spacers 14, 16 are arranged to produce mutually perpendicular flow directions on the two surfaces 11, 12.

[0105] At each protrusion 19, 21a, 21b, 24a, 24b, 26 on the first surface 11, there is a complementary groove / formed portion on the second surface 12, not shown in the figure.

[0106] Each spacer extending from the corresponding protrusion has a height higher than the corresponding protrusion relative to the corresponding face of cell 10.

[0107] Specifically:

[0108] - All spacers 14 on the first surface 11 have the same height relative to the first surface.

[0109] - All spacers 16 on the second surface 12 have the same height relative to the second surface.

[0110] Furthermore, the surface shape of cell 10 is defined as follows:

[0111] - In the first part 13a and the corresponding third part 15a, the dome 100 has an elliptical profile.

[0112] - In the second part 13b and the corresponding fourth part 15b, there are two semi-dots 100a and 100b with semi-elliptical profiles that are mirror-symmetric with respect to the second axis Y, namely the first semi-dot 100a and the second semi-dot 100b.

[0113] Specifically, the minor axis of the ellipse of the dome 100 is located at the sixth spacer 28 and the major axis of the ellipse extends between the fourth spacers 25a and 25b.

[0114] The dome 100 has a concave surface facing the first surface 11 and a corresponding convex surface facing the second surface 12, with the apex located at the sixth spacer 28.

[0115] In fact, the dome 100 defines the protrusion facing the second surface 12.

[0116] The first semi-dome 100a has:

[0117] - The long semi-axis at the fifth protrusion 26 extends between the seventh spacer 29a and the fifth spacer 27.

[0118] - The short shaft at the seventh spacer 29a.

[0119] The first semi-dome 100a has a concave surface facing the first surface 11 and a corresponding convex surface facing the second surface 12, wherein the vertex is at the seventh spacer 29a.

[0120] In fact, the first semi-dome 100a defines the protrusion facing the second surface 12.

[0121] The second semi-dome 100b has:

[0122] - The long semi-axis at the fifth protrusion 26 extends between the seventh spacer 29b and the fifth spacer 27.

[0123] - The short shaft at the seventh spacer 29b.

[0124] The second semi-dome 100b has a concave surface facing the first surface 11 and a corresponding convex surface facing the second surface 12, with the vertex located at the seventh spacer 29b.

[0125] In fact, the second semi-dome 100b defines the protrusion toward the second surface 12.

[0126] The dome 100 and the semi-domes 100a and 100b provide a protrusion of about 0.05 mm to 0.3 mm to the second surface 12 in contact with the hot fluid, and are adapted to partially compensate for deformation caused by the concave effect occurring on the first surface 11 in contact with the cold fluid.

[0127] Figure 2 A plate heat exchanger 30 according to the present invention is shown.

[0128] Exchanger 30 is of the air / air type.

[0129] Figure 3 and Figure 4 An exploded view and a portion of a cross-sectional side view of the internal region of the exchanger 30 are shown.

[0130] In a proper connection of the plates, the two plates 1 are arranged in the same direction and face the same surfaces 11 and 12.

[0131] The plates are joined by rotating one plate 180° onto another, such that only the spacers 14, 16 and the corresponding edges of the two continuous plates are in contact.

[0132] The matching results of the boards are as follows Figure 5 and Figure 6 As shown.

[0133] Figure 5 The arrangement of the plates in the exchanger 30 and the resulting piping as seen from the cold side where the processed fluid is located are schematically illustrated. Figure 6 The arrangement of the boards in the switch 30 and the resulting piping as seen from the hot side where the data center is located are schematically illustrated.

[0134] The exchanger 30 has pipes 81 for hot fluids and pipes 80 for cold fluids arranged in mutually parallel planes at 90° to each other.

[0135] In particular, such as from Figure 4 , Figure 5 and Figure 6 It becomes clear that the cross-sections of pipes 80 and 81 are hexagonal, which is due to the connection of the two consecutive plates by means of the same faces 11 and 12 pointing to the two consecutive plates 1.

[0136] The hexagonal cross-sections of pipes 80 and 81 have two slender sides opposite each other, namely 82a, 82b, 83a and 83b, and four other sides that are inclined relative to the preceding slender sides and taper toward the mutual support / contact points 86 and 87 between the two continuous plates 1, namely 84a, 84b, 84c, 84d, 85a, 85b, 85c and 85d.

[0137] As described above, the switch 30 has multiple boards 1.

[0138] Specifically, the plates 1 are connected so that they face each other on the same surface, first surface 11 or second surface 12, of the corresponding cells 10, and each spacer of the first surface 11 of cell 10 faces and contacts the corresponding spacer of the first surface 11 of the next cell 10, and is similarly arranged with respect to the second surface 12.

[0139] In fact, in order to assemble the switch 30, it is sufficient to arrange the boards 1 in series and rotate them 180° relative to the plane in which they are arranged.

[0140] Figure 3 It is shown that:

[0141] - Arrow C basically indicates the direction of travel of the cold fluid.

[0142] - Arrow F indicates the direction of travel of the hot fluid.

[0143] exist Figure 4 In the diagram, arrow P indicates the pressure advance on each face of the plate of exchanger 30.

[0144] The first surface 11, which is in contact with the cold side, is subjected to negative pressure, while the second surface 12, which is in contact with the hot side, is subjected to positive pressure.

[0145] The tension is balanced at the contact point, so the displacement is essentially zero, thereby reducing the deformation of the plate.

[0146] Experimental tests and finite element calculations show that the arrangement and number of spacers on the two surfaces can reduce / eliminate plate deformation caused by the pressure difference between the two surfaces.

[0147] Between the cold side where the fluid is handled and the hot side where the data center is located, the spacers differ in number, shape, size, and function.

[0148] Specifically, the cold side is the side that contacts the first surface 11 of the plate 1, while the hot side is the side that contacts the second surface 12 of the plate 1.

[0149] These types of spacers are mainly suitable for:

[0150] - Separate plate 1 to create pipes perpendicular to each other for cold fluid (processing fluid) and hot fluid (data center fluid).

[0151] -Increase the mechanical properties of the cold side where the processed fluid is located.

[0152] The piping on the hot side, where the data center is located, is subjected to positive pressure, while the piping on the cold side, where the fluids are processed, is subjected to negative pressure.

[0153] Therefore, a pressure differential is generated, which is the sum of the absolute values ​​of the positive and negative pressures between the pipes on the data center side, which tend to expand, and the pipes on the processing fluid side, which tend to collapse, and this determines the pressure load that a single board must withstand.

[0154] The spacers on the hot side (data center side) are subjected to a small portion of pressure load because the pressure difference tends to pull individual spacers away from their corresponding spacers (traction effect).

[0155] The spacers on the cold side (processing fluid side) must withstand most of the pressure load because the pressure difference tends to push individual spacers toward their corresponding spacers (compression effect).

[0156] From a mechanical point of view, the total pressure load is symmetrical to the plane on the contact surface of the spacer located on the cold side (the fluid handling side).

[0157] On this contact surface, the pressure load is completely released / balanced, so the displacement is zero.

[0158] Therefore, the spacers on the cold side (processing fluid side) need to have a robust shape and structure, and there need to be more spacers than on the hot side to ensure sufficient structural rigidity of the plate and prevent deformation that could block the path of the processed fluid, thus affecting the operation of the heat exchanger.

[0159] The difference is that the spacers on the hot side (data center) are tapered in shape and fewer in number to minimize flow resistance on the hot side, and because they have almost no impact on the structural stiffness of the plate during use.

[0160] In particular, the tapered shape on the hot side (second side 12) and the smaller number of spacers create small obstructions (or concentrated resistance) in the path of the fluid originating from the data center.

[0161] For example, view Figure 1a The tension state that develops along the R-line passing through the spacer 14 on the cold side can be presented in the following manner.

[0162] As for the segment along line R, it consists of the following parts: half spacer 14 corresponding to the fourth spacer 25a, the fourth protrusion 24a, the sixth spacer 28 (hot side) and the fourth protrusion 24b, and half spacer 14 corresponding to the fourth spacer 25b.

[0163] This segment repeats periodically until the end of plate 1, and its effect is negligible. Figure 7 As shown.

[0164] The fourth spacers 25a and 25b are schematically shown as being firmly connected, and they have the following boundary conditions:

[0165] - The vertical displacement is essentially zero, and the corresponding fourth spacers 25a and 25b of the subsequent plate are in contact.

[0166] - The horizontal displacement is essentially zero, indicating there is no load in that direction.

[0167] - The angular displacement is essentially zero due to the periodicity of the previous / next segment.

[0168] The sixth spacer 28 is schematically shown as being connected by static contact and capable of yielding, and it has the following boundary conditions:

[0169] - Allows vertical movement, yielding connection.

[0170] - The horizontal displacement is essentially zero, indicating there is no load in that direction.

[0171] - The angular motion is essentially zero due to the symmetry of the structure and load relative to the midpoint of the plate.

[0172] The fourth protrusions 24a, 24b are schematically shown as a whole as beam T, having:

[0173] - Static moment of inertia (I),

[0174] - Young's modulus (E),

[0175] - Length (2L),

[0176] - Beam T is subject to:

[0177] - Distributed load (q), which consists of the pressure difference acting on the plate,

[0178] - Concentrated load (k), which is composed of the reaction force of the yield connection determined by the sixth spacer 28.

[0179] Figure 7 The tension diagram in Figure 8 and Figure 9 can be decomposed into two tension sub - diagrams, as shown, and when they are added together, the overall tension diagram is obtained.

[0180] The first sub - diagram, as shown in Figure 8 shows beam T1 with a distributed load q supported at both ends.

[0181] Looking at Figure 8 beam T1 has:

[0182] - Moment: where it is maximum at the mid - point (t = L) and equal to:

[0183] - Deflection: where 0 < t < 2L, and it is maximum at the mid - point (t = L) and equal to:

[0184] The second sub - diagram, as shown in Figure 9 shows beam T2 with a concentrated load k at the mid - point supported at both ends.

[0185] Looking at Figure 9 beam T2 has:

[0186] - Moment: where it is maximum at the mid - point (t = L) and equal to: ;

[0187] - Deflection: where 0 < t < L, and it is maximum at the mid - point (t = L) and equal to:

[0188] Therefore, Figure 7 the overall deflection of beam T in

[0189]

[0190] The case where k = 0 corresponds to the conditions described in the first sub - figure, as Figure 8 shown.

[0191] The case where k = qL corresponds to the rigid static support condition, such that f sys = 0.

[0192] The case where k < qL corresponds to the condition of a yielding connection, which is schematically represented by the sixth spacer 28 (hot side, data center).

[0193] In order to reduce the overall camber f sys , it is necessary to act on at least one of the parameters on which it depends: E, q, L or I:

[0194] - It is not possible to act on the Young's modulus (E) to increase it, because the material and its Young's modulus are design parameters,

[0195] - It is not possible to reduce the range of the distributed load q, because this would limit the thermodynamic performance,

[0196] - It is possible to reduce the length L of the beam, but an appropriate compromise must be made between thermodynamic performance and mechanical strength, because an excessive reduction in the length L would make the density per unit surface area of the spacer 14 greater, and consequently a local flow resistance would arise, which would impair the thermodynamic performance;

[0197] - It is possible to increase the static moment of inertia I, but an appropriate compromise must be made between thermodynamic performance and mechanical strength, because an excessive change in the cross - section would create a critical state at the technical / production level due to implementation difficulties and would also impair the thermodynamic performance.

[0198] As previously mentioned, the distribution of the protrusions and spacers enables satisfactory thermodynamic performance to be obtained by optimizing the geometry (especially the profile) of the plate 1, thereby increasing the static moment of inertia I while ensuring sufficient mechanical strength.

[0199] Reference Figure 10 and Figure 11 , in terms of the cross - section of the plate taken along the Q section, the contribution of the static moment of inertia I is shown below, and the differences between common profiles of flat plates are analyzed, represented as a flat beam in Figure 10 and an optimized profile, represented as a beam with a Ω - shaped cross - section in Figure 11 , such as in the case of the Q section of the plate according to the present invention.

[0200] The aim is to highlight the benefits brought by the optimized profile of the geometry of the plate according to the present invention.

[0201] For the sake of simplicity, the effect of ripples has been ignored.

[0202] by Figure 10 The beam shown is an example with a flat cross-section, wherein:

[0203] - Width w = 30mm

[0204] -Thickness h=0.3mm,

[0205] The static moment of inertia I of the flat cross-section relative to its centroid G is:

[0206] Regarding the lower side of the cross-section at a height Regarding the center of gravity G.

[0207] To increase the static moment of inertia I, we can manipulate the parameters w and h.

[0208] However, increasing the width w leads to an increase in the surface area of ​​the plate, thereby increasing the distributed load acting on it, while decreasing the width leads to a decrease in the static moment of inertia, a decrease in the surface area of ​​the plate, thereby decreasing the distributed load acting on the plate.

[0209] Therefore, the choice of width w must be a compromise to obtain sufficient thermodynamic properties.

[0210] On the other hand, increasing the thickness h will lead to the use of more plastic material to manufacture the sheet, resulting in increased costs.

[0211] Furthermore, from the perspective of plate manufacturing, thickness h is an important parameter.

[0212] Therefore, the minimum thickness h that allows for successful thermoforming must be selected.

[0213] Alternatively, with Figure 11 The beam shown here has an Ω-shaped cross-section as an example, wherein:

[0214] - Width w = 30mm

[0215] -Thickness h=0.3mm,

[0216] -First feature dimension a = 2mm,

[0217] -Second feature dimension b = 14 mm,

[0218] The static moment of inertia I of the Ω-shaped cross section relative to its centroid G is:

[0219] Regarding the lower side of the cross-section at a height Regarding the center of gravity G.

[0220] It can be seen that, for the same width w and thickness h, introducing an Ω-shaped section instead of a flat section will significantly increase the static moment of inertia I.

[0221] Using CFD (Computational Fluid Dynamics) simulations, it has been verified that the proposed geometry can achieve satisfactory heat exchange conditions.

[0222] Furthermore, the specific arrangement of the spacers, as well as the size, shape, and number of these spacers, allows for the restriction of the deformation of cell 10 and its bending toward the cold side.

[0223] Figure 12 and Figure 13 The results of two finite element simulations of a portion of plate 1, with a thickness of 0.3 mm, are shown graphically as examples, under operating conditions with a pressure of 3000 Pa on one side of the second surface 12.

[0224] In the simulation, the Young's modulus of the material was set to E = 2250 MPa, and the Poisson's ratio was set to ν = 0.34.

[0225] Figure 12 The tension distribution on a portion of the plate according to the von Mises yield criterion is illustrated graphically, where:

[0226] - The region represented by 65 is the region with zero tension.

[0227] - The region represented by 64 is the region with a tension of 1 MPa.

[0228] - The region represented by 62 is the region with a tension of 2 MPa.

[0229] - The region represented by 63 is the region with a tension of 3.1 MPa.

[0230] - The region indicated by 61 is the region at the longitudinal end of the spacer where the tension is the maximum and equal to 4.7 MPa. These regions are surrounded by region 63.

[0231] Figure 13 The finite element simulation results of the deformation of the plate according to the invention on a portion of the plate during operation are shown graphically, wherein:

[0232] - The area represented by 71 is the region with the maximum displacement equal to 0.11 mm.

[0233] - The area represented by 72 is the area where the displacement is equal to 0.07 mm.

[0234] - The area represented by 73 is the region where the displacement is equal to 0.04 mm.

[0235] - The area represented by 74 is the area where the displacement is equal to 0.009 mm.

[0236] - The area represented by 75 is the area with negative displacement, which is equal to -0.0025mm.

[0237] It should be noted that the plate according to the invention is advantageous for low flow resistance relative to the hot side of the plate under partial vacuum, so as to achieve improved energy consumption.

[0238] Furthermore, due to the symmetry of the lateral contact points in the partial vacuum between the plates, the tension is balanced at the contact points. This results in displacement and thus reduces the deformation of the plates.

[0239] In practice, it has been found that the present invention fully achieves the intended goals and objectives by providing a plate for a heat exchanger, wherein the pressure difference between the hot and cold sides does not cause deformation of the plate, and / or results in minimal deformation even if the plate is made of a material with a low Young's modulus.

[0240] This invention has led to the design of a plate for heat exchangers made of a material with low Young's modulus, which makes it possible to obtain better benefits by limiting flow resistance compared to similar conventional plates.

[0241] Furthermore, according to the present invention, the heat exchanger is provided with a plate capable of achieving the above-mentioned objectives.

[0242] This invention, conceived in this way, allows for a variety of modifications and variations, all of which are within the scope of the appended claims. Furthermore, all details can be replaced by other technically equivalent elements.

[0243] In practice, the materials used, as well as the possible sizes and shapes, can be determined based on requirements and the level of existing technology, provided they are compatible with the specific application.

[0244] This application claims priority to Italian patent applications No. 102020000023473 and No. 102021000023270, the disclosures of which are incorporated herein by reference.

[0245] Where a technical feature mentioned in any claim is followed by a reference numeral, the sole purpose of including such reference numerals is to increase the comprehensibility of the claim; therefore, such reference numerals do not limit the interpretation of each element identified by way of such reference numerals.

Claims

1. A plate for a heat exchanger, the plate comprising a plurality of cells (10), each cell (10) comprising a first surface (11) and a second surface (12) opposite to the first surface (11), the first surface (11) and the second surface (12) having a plurality of spacers (14, 16) arranged to create mutually perpendicular flow directions between the first surface (11) and the second surface (12). in, Each of the cells (10) has a quadrilateral outline, and the first face (11) and the second face (12) have corrugations. The first axis (X) of each cell (10) is substantially centered and perpendicular to the direction of the ripples. The second axis (Y) of each cell (10) is substantially centered and parallel to the direction of the ripples. The first face (11) comprises two parts: a first part (13a) and a second part (13b). The second face (12) comprises two parts: a third part (15a) which corresponds to and is opposite to the first part (13a); and the fourth part (15b), which corresponds to and is the opposite of the second part (13b), The plurality of spacers (14, 16) differ in at least one aspect of number, shape, and size between the first surface (11) and the second surface (12). The first surface (11) has two or more longitudinal end protrusions (21a, 21b) extending parallel to the first axis (X), each longitudinal end protrusion being located at the peripheral edge of each cell (10). Each of the two or more longitudinal end protrusions includes two or more longitudinal end spacers of the plurality of spacers, the two or more longitudinal end spacers rising from the two or more longitudinal end protrusions and being substantially mirror-symmetrical with respect to a plane of symmetry perpendicular to the first axis (X) and passing through the second axis (Y).

2. The plate for a heat exchanger according to claim 1, characterized in that, The plate is made of a material with a low Young's modulus.

3. The plate for a heat exchanger according to claim 1, characterized in that, The plate is made of plastic materials such as PVC and / or PP and / or PET.

4. The plate for a heat exchanger according to claim 1, characterized in that, The plate is made of a material whose Young's modulus is substantially between 1000 MPa and 3000 MPa.

5. The plate for a heat exchanger according to claim 1, characterized in that, Each of the spacers (14, 16) has a facade perpendicular to the plane of the corresponding face (11, 12) and is integrally formed with the rest of the plate (1).

6. The plate for a heat exchanger according to claim 1, characterized in that: At each spacer (14) on the first surface (11), there is a complementary cavity / forming portion (17) on the second surface (12). At each spacer (16) of the second surface (12), there is a complementary cavity / formed portion (18) on the first surface (11).

7. The plate for a heat exchanger according to claim 1, characterized in that, The first surface (11) has a longitudinal first protrusion (19) extending along the first axis (X) and two first spacers (20a, 20b) raised from the first protrusion (19), the two first spacers (20a, 20b) being substantially mirror-symmetric with respect to a plane of symmetry of a second axis (Y) perpendicular to the first axis (X) and passing through each of the cells (10).

8. The plate for a heat exchanger according to claim 1, characterized in that, The two or more longitudinal end protrusions are respectively: The second protrusion (21a) and two second spacers (22a, 22b) rise from the second protrusion (21a) and are substantially mirror-symmetrical with respect to the plane of symmetry that is perpendicular to the first axis (X) and passes through the second axis (Y). The third protrusion (21b) and two third spacers (23a, 23b) rise from the third protrusion (21b) and are substantially mirror-symmetrical with respect to the plane of symmetry that is perpendicular to the first axis (X) and passes through the second axis (Y).

9. The plate for a heat exchanger according to claim 1, characterized in that, The first portion (13a) has two fourth protrusions (24a, 24b), each of which extends along a fundamental central axis of the first portion parallel to the first axis (X), and fourth spacers (25a, 25b) extend from each of the fourth protrusions (24a, 24b) at a corresponding peripheral edge of each cell (10) parallel to the second axis (Y).

10. The plate for a heat exchanger according to claim 1, characterized in that, The second part (13b) has a longitudinal fifth protrusion (26) extending along a fundamental central axis of the second part parallel to the first axis (X), and a fifth spacer (27) protruding from the fifth protrusion (26) at the second axis (Y).

11. The plate for a heat exchanger according to claim 1, characterized in that, The third part (15a) has a sixth spacer (28) extending along the second axis (Y).

12. The plate for a heat exchanger according to claim 1, characterized in that, The fourth part (15b) has two seventh spacers (29a, 29b), each seventh spacer being located at the peripheral edge of each cell (10) parallel to the second axis (Y).

13. The plate for a heat exchanger according to claim 1, characterized in that, The protrusions (19, 21a, 21b, 24a, 24b, 26) are integrally formed with the rest of the plate (1).

14. The plate for a heat exchanger according to claim 1, characterized in that, At each protrusion (19, 21a, 21b, 24a, 24b, 26) on the first surface (11), there is a complementary groove / formed portion on the second surface (12).

15. The plate for a heat exchanger according to claim 1, characterized in that: All spacers (14) of the first surface (11) have the same height relative to the first surface. All spacers (16) of the second surface (12) have the same height relative to the second surface.

16. The plate for a heat exchanger according to claim 1, characterized in that, The surface shape of each cell (10) is defined as follows: The first part (13a) and the corresponding third part (15a) have domes (100) with elliptical outlines. In the second part (13b) and the corresponding fourth part (15b), there are two semi-elliptical domes (100a, 100b) that are mirror-symmetrical with respect to the second axis (Y), and the domes (100) and the semi-elliptical domes (100a, 100b) are provided with protrusions facing the second surface (12).

17. A plate heat exchanger, characterized in that, The plate-type heat exchanger includes a plurality of plates (1), each of which is a plate for heat exchanger according to any one of claims 1 to 16.

18. The plate heat exchanger according to claim 17, characterized in that, The plates (1) are connected so that they face each other with the same first face (11) or second face (12) of the corresponding cells (10), and such that: Each spacer (14) of the first face (11) of cell (10) faces and contacts the corresponding spacer (14) of the first face (11) of the next cell (10). And / or, each spacer (16) of the second face (12) of cell (10) faces and contacts the corresponding spacer (16) of the second face (12) of the next cell (10).

19. The plate heat exchanger according to claim 17 or 18, characterized in that, The plate (1) is arranged to rotate 180° relative to its own plane of arrangement.

20. The plate heat exchanger according to claim 19, characterized in that, The connection between the plates (1) is achieved in such a way that only the spacers (14, 16) contact the corresponding edges of the two continuous plates (1).

21. The plate heat exchanger according to claim 18, characterized in that, The exchanger has pipes (81) for hot fluids and pipes (80) for cold fluids arranged in mutually parallel planes at 90° to each other.

22. The plate heat exchanger according to claim 21, characterized in that, Since the two consecutive plates (1) are connected by pointing to the same face (11, 12) of the two consecutive plates (1), the cross section of the pipe (80, 81) is hexagonal.

23. The plate heat exchanger according to claim 22, characterized in that, The hexagonal cross-section of the pipe (80, 81) has two elongated sides (82a, 82b, 83a, 83b) that are opposite each other and four other sides (84a, 84b, 84c, 84d, 85a, 85b, 85c, 85d) that taper relative to the elongated sides and toward the points (86, 87) of mutual support / contact between two continuous plates of the plate (1).

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