TUBE ASSEMBLY FOR A TUBE-TYPE HEAT EXCHANGER DEVICE

Description

Technical Field

[0001] The invention relates to a tube assembly for a tube-type heat exchanger device, and to a tube-type heat exchanger device that includes such a tube assembly.

Background Art

[0002] Various heat exchanger (HE) devices are known that are specifically adapted for industrial applications. Such conventional HE devices typically comprise a plurality of HE plates or tubes, which form thermally connected fluid channels through which fluid streams with different temperatures can flow. This allows thermal energy from the hotter fluid to be transferred to the colder fluid without matter being exchanged between these fluids.

[0003] One known type is the plate-type HE device, which comprises flat and parallel plates that form heat transfer (HT) areas and flat fluid channels in between each pair of plates. The plate-type HE device can be made relatively compact and allows the fluids to flow in a uniform and non-detached manner on both sides of the HE device. During operation, high mechanical stresses may occur in the plates, even at moderate pressure differential on the two sides of the plate. A plate-type HE device is unable to cope with high overpressures in the flowing fluids. Typically, the allowed overpressures are limited to a range of 0.5 to 1.5 bar gauge (barg).

[0004] Another known type is the conventional tube-type HE device, in which the heat transfer areas are formed by an array of cylindrical tubes. An advantage of conventional tube-type HE devices lies in their ability to cope with high overpressures inside the tubes (e.g. hundreds of bars). The fluid flows are highly non-uniform outside the tubes of this conventional HE device. In addition, the conventional tube-type HE is bulky and imposes great demands on manufacturing efforts and costs.

[0005] Chinese patent document CN104101235 describes a tube-type HE device that comprises a housing and HE tubes with rectangular cross-sections. These rectangular tubes are arranged alongside but at distances from each other. The housing comprises two oppositely disposed mounting plates onto which opposite distal ends of the rectangular tubes are mounted. Each mounting plate is provided with an array of rectangular fluid discharge holes, each hole being fluidly connected to a fluid passage that extends through a respective tube. This known HE device has low mechanical strength, sub-optimal heat-transfer efficiency, and is relatively difficult to manufacture.

[0006] DE 102012220435 A1 discloses a tube assembly according to the preamble of claim 1.

[0007] It would be desirable to provide a tube assembly for a tube-type HE device, in which at least one of the mechanical strength properties and the heat transfer efficiency is improved.

Summary of Invention

[0008] Therefore, according to a first aspect of the invention, there is provided a tube assembly for a tube-type heat exchanger (HE) device according to claim 1.

[0009] The proposed tube assembly forms an alternating (interleaved) arrangement of first and second fluid channels, with first channels formed by a row of adjacent tubes, and with second channels formed by spaces between distinct tube rows. The complementary surface shapes of the lateral wall portions of the tubes allow these tubes to adjoin and be (interconnected to form a tube row. The flow passages of the tubes in a tube row may jointly form one first fluid channel that provides passage to a first fluid with initial physical properties (e.g. composition, pressure, temperature, velocity, etc.).

[0010] Alternatively, the adjacent flow passages of tubes in one tube row may provide passage to distinct fluids. For instance, the first fluid may flow through a first selection of the tubes in this row, and a further fluid with different composition, pressure, temperature, and/or velocity may flow through a further (i.e. distinct) selection of the tubes in this row.

[0011] In each of these cases, combining tubes with complementary lateral surfaces into rows of laterally adjoining tubes yields a compact tube arrangement that can sustain high pressures for the first fluid(s) inside the first channels, and which is highly resistant to mechanical stress exerted on the tube rows. The arrangement of rows with closely adjoining tubes (i.e. without passages between tubes in the same row) prevents fluid in one second channel from passing between two tubes and mixing with fluid in the next second channel, which would cause unwanted pressure differentials near tube edges. The adjoining tubes do not increase the flow resistance in a mannerthat negatively impacts the heat transfer efficiency. The ordered tube arrangement may further ensure that the flow distributions for the first and second fluids remain relatively uniform and non-detached inside the first and second channels as well as outside the inlets and outlets of the HE device.

[0012] In embodiments, the outer surfaces of adjacent tubes are interrupted by level variations (for instance grooves or protrusions) in the third direction, which are elongated in the first direction along the tubes but localized in the second direction, and which are adapted to generate local turbulence in the second fluid flow that passes through a second fluid channel along the outer surfaces when the tube-type HE device is in operation. Preferably, the tubes in the tube row extend transversely to an associated second fluid channel that is bordered by the outer surfaces of these tubes. At least two of these outer surfaces may be interrupted by a level variation in the third direction. This level variation extends in the first direction along a boundary line between two directly adjacent tubes, and is adapted to generate local turbulence in the second fluid flow that passes predominantly in the second direction through the second fluid channel and across the outer surfaces and the level variation, when the tube-type HE device is in operation.

[0013] In known plate-type HE devices with HT plates having flat main HT regions and rectangular ducts with large aspect ratio, for instance as disclosed in patent document CA2030577, a transition from laminar to turbulent flow in a fluid passing the HT plates may be triggered at Reynolds numbers below 10000. Such a transition typically involves a sequence of stages that may be described as 1) Tollmien Schlichting waves, 2) deformed Tollmien Schlichting waves with three-dimensional vorticity, 3) three-dimensional breakdown, 4) turbulent spots, and 5) fully turbulent flow. In this context, "fully developed" means that transverse cross-sectional velocity and velocity fluctuation distributions of a turbulent fluid stream at various downstream positions are essentially identical.

[0014] By contrast, the local level variations between and along pairs of adjacent tubes, which are highly localized in the direction along the second fluid flow, disrupt the boundary layer of the second fluid flow (i.e. the flow layers close to the further tube wall portions). The local turbulent flow perturbations triggered by the level variations improve the attachment of the second fluid flow to the outer surfaces of the further tube wall portions, thus enhancing the heat transfer efficiency. The level variations may be provided between each pair of adjacent tubes, or between selected pairs of adjacent tubes. The level variations may be formed by grooves that are receded with respect to the outer surfaces of the further tube wall portions, or by ridges that are elevated with respect to the outer surfaces.

[0015] According to embodiments, one or more of the tube rows comprises at least one plate structure that is fixed to and interposed between two tubes, and extends along the first and third directions. This plate structure protrudes along the third direction with a height relative to at least one of the outer surfaces of the further tube wall portions and into part of the respective second fluid channel, to form one of the level variations for generating local turbulence in the second fluid flow. The height of the protrusion may be in a range between 10% and 20% of a height of the corresponding second fluid channel.

[0016] The plate structure protrudes only into a part of the respective second fluid channel near the outer wall surface, to trigger turbulent flow perturbations in the boundary layer of the second fluid flow close to the further tube wall portions, while shortening or even bypassing the above sequence of stages. This plate structure may help to trigger local turbulent flow inside the second fluid channel at low Reynolds numbers (as low as Re = 500), thus extending the operational range and heat transfer efficiency of the HE device.

[0017] The plate structures may extend in the first direction along essentially the entire length of the tubes. The structures may protrude relative to the further wall portions to define height profiles along the third direction that vary with position along the first direction. These height profiles may alternate along the positive and negative third direction as function of position along the first direction. The height profiles may include symmetrical or asymmetrical shapes, and may for instance (viewed along the second direction) resemble a sine profile, a chirped profile, or a profile with a sequence of edges that are mutually oriented at non-zero angles to define sharp corners. These sharply cornered edges induce small-scale flow perturbations along both transverse directions (X and Z) in the impinging second flow. The height profile may for instance define a polygonal contour. In this context, the term "polygonal" implies that a projection of a protruding part in the plate structure has the shape of (part of) a simple polygon (e.g. a triangle, tetragon, pentagon, etc.). A profile with a polygonal contour has relatively sharp edges in the plane perpendicular to the direction of the second fluid flow.

[0018] In a further embodiment, the plate structure protrudes in opposite directions along the third direction relative to both the outer surfaces of the further wall portions into part of the second fluid channels on both sides of the at least one tube row.

[0019] In embodiments, the tubes are interconnected by being mutually fixed via weld lines that extend along lateral edges of the respective lateral wall portions of the tubes. The lateral edges may be leading lateral edges located at inlets of the flow passages, or trailing lateral edges located at outlets of the flow passages, or both. In addition, the tubes may be interconnected without using direct bonds along the length of the lateral tube walls.

[0020] The tubes can be connected together via welding along their leading and/or trailing lateral tube edges, which allows for simple and efficient construction methods. The welding can be performed one a tube-by-tube basis, or in a continuous manner along multiple tubes that have been properly aligned in advance.

[0021] According to embodiments, the tube assembly comprises spacers that extend in the second flow direction and along the further wall portions of the tubes, and extend in the third direction along a full height of a respective second fluid channel, to provide non-zero mutual spacing between the tube rows along the third direction. The tube assembly may thus be formed by simple construction methods that involve repetitive and alternating stacking of rows of tubes and spacers.

[0022] For a tube assembly in which the further wall portions are substantially flat and level, the spaces are preferably formed by elongated members, each having upper and lower surfaces that are substantially flat and mutually parallel, to support and be supported along edges of mutually parallel tube rows. Lateral surfaces of such elongated spacer members may have a flat, polygonal, or curved shape. The lateral surface that faces inwards towards the second fluid channel may for instance have a single concave shape, to form a smooth transition with the above- and below-situated flat tube arrays, and to form a second fluid channel with a cross-sectional contour resembling a stadium. Alternatively or in addition, the lateral surface facing outwards may have a concave shape with upper and lower edges projecting laterally outwards and being aligned with the lateral surfaces of the outer tubes, to provide crests that facilitate welding of the spacer member to the above- and below-situated tube rows. In a particularly simple alternative, the spacers may be formed by bars with regular polygonal (e.g. rectangular) cross-sections.

[0023] The spacers may include leading spacers located at or near leading further edges of the further wall portions at inlets of the flow passages, or trailing spacers located at or near trailing further edges of the further wall portions at outlets of the flow passages, or both.

[0024] In embodiments wherein the spacers and tube rows are mutually fixed, the spacers and tubes may consist essentially of the same material. This mitigates in-plane differential thermal expansion effects between a spacer and the tube rows directly connected thereto, when the HE device is in operation.

[0025] In further embodiments, the tube assembly comprises a further tube row formed of tubes that are consecutively arranged along the second direction. This further tube row is adjacent to the at least one row and aligned therewith relative to the second direction, so that lateral wall portions of the tubes in the adjacent tube rows line up in the third direction. Here, the weld lines may form continuous weld lines that extend along consecutive adjacent lateral edges of the lateral wall portions as well as across the spacers.

[0026] In further embodiments, the tubes in the at least one tube row are fixed to an adjacent leading spacer via a further weld line along the leading further edges of the tubes and a leading surface of the leading spacer, or to an adjacent trailing spacer via a further weld line along the trailing further edges of the tubes and a trailing surface of the trailing spacer, or both.

[0027] In alternative embodiments, each of the tubes comprises a leading section that extends along the respective flow passage from a respective inlet, a trailing section extending along the flow passage from a respective outlet, and a medial section extending along the flow passage between the leading and trailing sections. At least one of the further tube wall portions may converge along the third direction towards the nominal axis in the leading section, so that the flow passage narrows with position along the first direction. Alternatively or in addition, at least one of the further wall portions of the tubes may diverge along the third direction away from the nominal axis in the trailing section, so that the flow passage widens with position along the first direction.

[0028] In a further embodiment, adjacent tube rows of tubes may adjoin along leading further edges of the further tube wall portions located at inlets of the flow passages. Alternatively or in addition, these adjacent tube rows may adjoin along trailing further edges of the further tube wall portions located at outlets of the flow passages. Throughout the medial sections, the adjacent tube rows are mutually spaced in the third direction, to enclose the second fluid channels.

[0029] The adjacent tube rows may be mutually fixed via continuous further weld lines along the leading further edges, and/or via continuous further weld lines along the trailing further edges. Fixing tube rows with continuous further weld lines along the leading and/or trailing further edges obviates the need for intermediary spacers and reduces the number of required welding operations. Also in this case, the tubes may be interconnected without using direct bonds along the length of the lateral tube walls.

[0030] In embodiments, the bounding wall of each tube has a substantially uniform thickness in the second and third directions. The wall thickness may for instance range from 0.5 to 5 millimeters, preferably between 1 and 2 millimeters, and for instance be approximately 1.5 millimeters. In embodiments that include plate structures between tubes, these plate structures may have a thickness in the second direction that is comparable to or smaller than the tube wall thickness, and one or two orders of magnitude smaller than a total width of a tube. The plate thickness may for instance be in a range from 0.1 to 2 millimeters, and more particular between 0.2 and 0.5 millimeters.

[0031] According to embodiments, the bounding wall of each tube forms a unitary wall structure, in which each of the lateral wall portions extends on both its opposite edge regions via an interconnecting edge portion into a respective one of the further wall portions. These edge portions may form the rounded or chamfered outer surfaces.

[0032] In embodiments, the bounding wall of each tube has substantially quadrilateral cross-sectional shapes, and preferably substantially rectangular cross-sectional shapes, in planes perpendicular to the first direction. The cross-sectional shapes of distinct tubes may be identical or different.

[0033] The tubes may have a width ΔY1 along the second direction Y and a height ΔZ1 along the third direction Z. A ratio of ΔY1 to ΔZ1 may range from 1 to 10, thus allowing a wide range of differential overpressures in the first fluid flows (e.g. about 2 to 30 barg) to be accommodated by the tubes. Preferably, the ratio of ΔY1 to ΔZ1 ranges between 1 and 5.

[0034] According to the invention, at least one of the further wall portions of the tubes in the at least one row comprises a medial wall region that is displaced along the third direction and away from the nominal axis, to define a local widening of the flow passage relative to the lateral wall portions and a local narrowing of the second fluid channel.

[0035] The resulting local deformations of the medial wall regions confer a periodically undulated form upon the second fluid channel. The resulting periodic height alternation along the second channel imparts a pulsating effect on the second fluid flow when the HE device is in operation. The further wall portions of the tubes may for instance be deformed so that each pair of tubes on opposite sides of the second fluid channel defines a Venturi profile viewed in cross-section along the second and third directions Y, Z. The resulting second fluid channels may thus be bounded in the third direction Z by a plurality of Venturi-shaped walls that form a repeating pattern along the second flow direction. In embodiments where grooves are provided between tubes for triggering local turbulences, the resulting agitation in the second fluid flow yields a higher turbulence level even at low Reynolds numbers (down to Re ≈ 500), thus enhancing the heat transfer efficiency.

[0036] In embodiments, the tubes may consist essentially of a metal, a metal alloy, a ceramic, or a glass. Tubes formed from these materials can be made thermally and mechanically stable, and able to withstand high temperature and pressure conditions.

[0037] In alternative embodiments, the tubes are formed from semi-finished tubes that consists essentially of metal or metal alloy, which are coated one or more sides of the tube with an enamel material, for instance a vitreous enamel (i.e. glass) layer, prior to arranging the tubes into the tube rows. Ceramics, full-glass, and enameled tube materials allow the tube assembly to operate in hostile environments in which at least one of the fluids is corrosive.

[0038] In embodiments, the bounding wall of the tube forms a unitary (i.e. monocoque) structure. Such unitary tubes may for instance be formed by known methods, e.g. by extrusion or casting methods, or by folding an elongated rectangular plate blank at least three times (preferably four times) along substantially parallel folding lines in a developable (i.e. single curved) manner and laterally closing the resulting tubular shape by bonding the long edges of the folded blank. For metal plate blanks, edge bonding may be achieved via known welding techniques, for instance high frequency electric welding, tungsten inert gas (TIG) welding, metal inert gas (MIG) welding, laser welding, etc.

[0039] According to a second aspect of the invention, and in accordance with the advantages and effects described herein above, there is provided a tube-type heat exchanger HE device comprising a frame, and a tube assembly according to the first aspect, which is mounted on an inner side of the frame.

[0040] In various HE device embodiments, the tubes in a tube row may either be straight, or be bent to form first channels that jointly curve and change direction along the flow path of the first fluid while maintaining lateral contact, for instance to form tube rows with a macroscopically Z-type, U-type, or undulated shape. Alternatively or in addition, the shapes of the second fluid channels may be varied along the flow path of the second fluid, by placing specifically shaped (e.g. curved) internal guiding vanes at various positions inside the second fluid channels, and/or by forming inlets and outlets of the second fluid channels at positions and with widths that span only part of the full width of the second fluid channels. Also the first fluid channels may thus be formed into macroscopically curved configurations, for instance of the Z-type, or U-type. Alternatively or in addition, the cross-sectional shape of the tube arrangement may be made to deviate from a uniform rectangular shape, by varying the widths of the distinct tube rows as function along the third direction, and/or by using spacer members with outer lateral surfaces that are slanted or curved to interconnect the above- and below-situated tube rows having edges that are mutually displaced.

Brief Description of Drawings

[0041] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts. In the drawings, like numerals designate like elements. Multiple instances of an element may each include separate letters and numbers appended to the reference number. For example, two instances of a particular element "30" may be labeled as "30a1" and "30b1". The reference number may be used without an appended letter and number (e.g. "30") to generally refer to an unspecified instance or to all instances of that element, while the reference number will include an appended letter and/or number (e.g. "30a1") to refer to a specific instance of the element.

Figure 1 shows a tube-type HE device according to an embodiment.

Figure 2a shows part of a tube assembly according to an embodiment.

Figures 2b and 2c show cross-sectional views of wall portions of adjacent tubes from the tube assembly in Figure 2a.

Figure 3 shows part of a tube assembly according to another embodiment.

Figure 4 shows part of a tube assembly according to yet another embodiment.

Figure 5a shows a cross-sectional view of part of a tube assembly according to another embodiment.

Figure 5b shows a plate structure from the tube assembly of Figure 5a.

Figure 6 shows a cross-sectional view of part of a tube assembly according to yet another embodiment.

Figure 7 shows a cross-sectional view of part of a tube assembly according to yet another embodiment.

[0042] The figures are meant for illustrative purposes only, and do not serve as restriction of the scope or the protection as laid down by the claims.

Description of Embodiments

[0043] The following is a description of exemplary embodiments of the invention, given by way of example only and with reference to the figures. Cartesian coordinates are used in the next figures to describe spatial relations for exemplary embodiments of the tube assembly.

[0044] Figure 1 schematically shows a perspective view of an embodiment of a heat exchanger (HE) device 10. The HE device 10 is of a tube-type, and includes a mounting frame 14 and a tube assembly 12 that is mounted in a receiving space enclosed by the frame 14. The tube assembly 12 defines a plurality of first fluid channels 22 that provide passage to a first fluid flow 26, and a plurality of second fluid channels 24 that provide passage to a second fluid flow 28.

[0045] The exemplary HE device 10 shown in figure 1 is of a cross-flow type, wherein the first and second fluid channels 22, 24 open up in an alternating manner on different but adjacent sides of the tube assembly 12. These first and second fluid channels 22, 24 form two distinct channel groups, which are connectable to distinct supply and discharge conduits (not shown) for fluid streams with different temperatures and compositions. In industrial applications, the temperatures and compositions of the fluids that make up the first and second fluid flows 26, 28 differ to such an extent that mixture of these fluids should be avoided. The preferred connections of the fluid channels 22, 24 to hot or cold fluid supply and discharge conduits will be determined by the desired operating conditions of the HE device 10 via methods known to the skilled person.

[0046] The frame 14 comprises two end panels 18a, 18b and four support members 16. The end panels 18 may be structurally reinforced plates that protect outer surfaces of the HE device 10. The end panels 18 are located on opposite sides of the tube assembly 12, and are oriented substantially parallel with the first and second fluid channels 22, 24.

[0047] In this example, the tube assembly 12 has a box-shaped outer contour, and the support members 16 are formed by four support beams 16a, 16b, 16c (16d) that are located at four corners of the HE device 10. The beams 16 are connected to the end panels 18 in respective beam connection regions 17, and jointly form a frame structure that encloses the receiving space in which the tube assembly 12 is mounted. For illustration purposes, only the upper end panel 18a in figure 1 is depicted in an exploded arrangement, and only three support beams 16a-c, one beam connection region 17d and part of sealing bellows 20d are shown.

[0048] In this exemplary embodiment, the heat exchanger 10 has sealing means 20a, 20b, 20c, 20d that are formed by bellows structures 20. Each bellows structure is provided between a corresponding beam 16 and a corner edge of the tube assembly 12, and extends along this corresponding beam 16 and the end panels 18. The bellows structures 20 serve to prevent leakage between, the first fluid flows 26 in the first channels 22 on the one hand, and the second fluid flows 28 in the second channels 24 on the other hand. The bellows structures 20 are sufficiently rigid to hold the tube assembly 12 in a fixed orientation between the frame components 16, 18 when the HE device 10 is in an inoperative state. Nevertheless, the bellows structures 20 are slightly flexible so that the tube assembly 12 is allowed to move and deform along the first and second directions X, Y relative to the beams 16 over a predetermined limited extent. The bellows 20 accommodate local differential expansion effects between the tube assembly 12 and the frame 14 during operation of the HE device 10. Further sealing means (not shown) similar to the bellows 20 may be provided between the end panels 18 and corresponding adjacent upper or lower edges of the tube assembly 12. These further sealing means may also be sufficiently rigid to hold the tube assembly 12 in a fixed orientation between the frame components 16, 18 when the HE device 10 is in an inoperative state, but slightly flexible so that the tube assembly 12 is allowed to move and deform along the third direction Z relative to the end panels 18 over a limited extent. The connections and orientations of the sealing means 20 may be adapted to the desired properties of the fluid flows 26, 28 and operating conditions of the HE device 10.

[0049] Figure 2a schematically shows details of the exemplary tube assembly 12 from the HE device 10 of figure 1. The tube assembly 12 comprises a plurality of tubes 30ij, which are grouped into a plurality of tube rows 32i. Here, i represents an index associated with distinct tube rows 32i (i.e. i = a, b, c, d,....), and j is an index associated with distinct tubes within one tube row (i.e. j = 1, 2, 3, 4,....). Additional tubes may be present in each tube row, but these are not shown in figure 2a for clarity reasons. The tube assembly 12 further comprises a plurality of spacers 54i, 55i arranged between vertically nearest tube rows 32i and 32i-1.

[0050] Each tube 30 includes a bounding wall 34 that surrounds a flow passage 36. This flow passage 36 extends in the first direction X and is centered on a nominal tube axis A. In this example, each tube 30 consists essentially of solid metal, and is formed as a rectangular structure with a shape in the first direction X that is elongated relative to its dimensions in the second and third directions Y, Z. The cross-sectional shape of the tube wall 34 perpendicular to the first direction X is substantially rectangular. This wall 34 includes two lateral wall portions 40, 41 on opposite lateral sides along the flow passage 36 (associated with the second direction Y), and two further wall portions 42, 43 on further opposite sides along the flow passage 36 (associated with the third direction Z). Each lateral wall portion 40/41 extends on both its opposite edge regions into a respective further wall portions 42/43. In this example, each tube 30 forms a unitary structure, and each tube wall 34 has a substantially uniform thickness Dt.

[0051] The tubes 30 all extend along the first direction X, such that the flow passages 36 jointly define first fluid channels 22 (see figure 1). Multiple tubes 30 are grouped and positioned alongside each other to form respective tube rows 32. Distinct tube rows 32 are mutually spaced along the third direction Z, such that a second fluid channel 24 is defined between each vertically adjacent pair of tube rows 32.

[0052] The tubes 30ij in each respective tube row 32i (i.e. varying j for one i) are joined and consecutively arranged along the second direction Y, so that the lateral wall portions 40, 41 of the tubes 30 adjoin. The flow passages 36 through the tubes 30 of one row 32 jointly form a linear array that defines one of the first fluid channels 22. In this example, the lateral wall portions 40, 41 of adjacent tubes 30 directly abut along their lateral outer surfaces, without an intervening structure being present between adjoining tubes 30. The upper further wall portions 42 of the tubes 30 in the row 32 lie in line and are substantially level, and define outer wall surfaces 44 that bound a second fluid channel 24 on an upper side of this row 32. Similarly, the lower further wall portions 43 of the tubes 30 in the tube row 32 lie in line and are substantially level, and define outer wall surfaces 45 that bound another second fluid channel 24 on a lower side of this row 32.

[0053] The outer surfaces 44, 45 of adjacent tubes 30 are interrupted by V-shaped grooves 62, 63 that extend in the first direction X in the direction of the tubes 30, but which extend only down/up to about 1 to 2 millimeters from the outer surfaces 44, 45. These grooves 62, 63 serve to generate local turbulence 64, 65 in the second fluid flows 28 that pass through the second fluid channels 24 when the tube-type HE device 10 is in operation.

[0054] Adjoining tubes 30 in each row 32 are mutually fixed by weld lines 60 that extend along leading lateral edges 46, 47 of the respective tube wall portions 40, 41. The leading lateral edges 46, 47 are located at the inlet 38 of the corresponding tube 30 (i.e. at the entrance side for the first flow 26). Similar interconnections are provided by weld lines 61 that extend along trailing lateral edges 50, 51 of the respective tube wall portions 40, 41. These trailing lateral edges 50, 51 are located at the outlet 39 of this tube 30 (i.e. at the exit side for the first flow 26).

[0055] In this example, the spacers are rectangular spacer bars 54, 55 that are formed from the same metal as the tubes 30. The spacer bars 54, 55 extend in the second flow direction Y along consecutive further tube wall portions 42/43 in a row 32. The spacer bars 54, 55 include leading spacer bars 54 located at or near leading further edges 48/49 of the further wall portions 42/43 at the inlets 38, and trailing spacer bars 55 located at or near trailing further edges 52/53 of the further wall portions 42/43 at the outlets 39. Each time, a second fluid channel 24i is bounded in the first direction X between a leading bar 54i and a trailing bar 55i. A height of the spacer bars 54, 55 along the third direction Z approximately equals a height ΔZ1 of the tubes 30, so that the second fluid channels 24 have heights ΔZ2 that are similar to the tube height ΔZ1.

[0056] In the example of figure 2a, the tubes 30 in distinct tube rows 32 are aligned in a lateral-vertical fashion, so that lateral wall portions 40, 41 of vertically adjacent tubes 30 line up in the third direction Z. The weld lines 58 and/or 59 can thus be made in a continuous manner, to extend along consecutive adjacent lateral wall edges 46-47 and/or 50-51, as well as across multiple spacer bars 54 and/or 55.

[0057] In the example of figure 2a, the leading/trailing surfaces 56/57 of the spacer bars 54/55 are arranged slightly receded inwards along the first direction X relative to the leading/trailing wall edges 46-49/50-53 of the tubes 30. The tubes 30 in each tube row 32 are fixed to an adjacent leading spacer bar 54 via a further weld line 60 near to and parallel with the leading further tube edges 48/49 and along a leading surface 56 of the leading spacer bar 54. Similarly, the tubes 30 in each tube row 32 are fixed to an adjacent trailing spacer bar 55 via another further weld line 61 near to and parallel with the trailing further tube edges 52/53 and along a trailing surface 57 of the trailing spacer bar 55.

[0058] The skilled person will appreciate that in alternative embodiments, the leading/trailing surfaces 56/57 may be level in the first direction X relative to the leading/trailing wall edges 46-49/50-53. In this case, the further weld lines 60/61 may extend directly along the leading/trailing further tube edges 48, 49 or 52, 53.

[0059] Figure 2b schematically shows a cross sectional view of two adjacent tubes 30 having lateral wall portions 40, 41 that are mutually fixed by a weld line 58. Each of the lateral wall portions 40, 41 has a leading lateral edge 46 resp. 47 that is tapered slightly outward relative to the flow passages 36 of the corresponding tubes 30. The tapered leading lateral edges 46, 47 of adjoining tubes 30 together form a V-groove inside and along which welding material is applied to form a robust mechanical connection.

[0060] Figure 2c illustrates the grooves 62, 63 between the outer wall surfaces 44, 45 in more detail. The tubes 30 are formed by unitary wall structures, with edge portions 66, 67 that each connect a respective lateral wall portion 40/41 to a further wall portion 42/43. The edge portions 66, 67 are curvedly bent with a radius of curvature R of about 1.5 millimeters, yielding a depth ΔZg of the grooves 62, 63 along the third direction Z and relative to the corresponding further wall portion 42, 43 which in this example is about 10% of a characteristic height ΔZ2 of the second channels 24.

[0061] Figure 3 shows another embodiment of a tube assembly 112. Features in this tube assembly 112 that have already been described above with reference to the tube assembly 12 (see figures 1-2b) may also be present in the tube assembly 112 in figure 3, and will not all be discussed here again. For the discussion with reference to figure 3, like features are designated with similar reference numerals preceded by 100 to distinguish the embodiments.

[0062] In the example of figure 3, each of the tubes 130 comprises a leading section 168 that extends from a respective inlet 138 into the associated flow passage 136, a trailing section 170 that extends from a respective outlet 139 into the flow passage 136, and a medial section 169 that extends along the flow passage 136 between the leading and trailing sections 168, 170.

[0063] In the leading section 168, the further wall portions 142, 143 of the tubes 130 converge in the third direction Z towards the nominal axis A, so that the flow passage 136 has a flared cross-sectional shape in a XZ-plane that narrows down with increasing X. Similarly, in the trailing section 170, the further wall portions 142, 143 diverge in the third direction Z away from the nominal axis A, so that the flow passage 136 has a flared cross-sectional shape in the XZ-plane that widens along increasing X.

[0064] In this example, adjacent tube rows 132 are joined along leading further edges 148, 149 of the further tube wall portions 142, 143 located at the inlets 138, and along trailing further edges 152, 153 of the further wall portions 142, 143 located at the outlets 139. Continuous further weld lines 160, 161 are provided along the leading further edges 148, 149 and the trailing further edges 152, 153 respectively.

[0065] The tube rows 132 remain mutually spaced in the third direction Z throughout the medial sections 169, so that the further tube wall portions 142, 143 of vertically adjacent tube rows 132 bound the second fluid channels 124 along the third direction Z.

[0066] Figure 4 shows another embodiment of a tube assembly 212. Features in this tube assembly 212 that have already been described above for the preceding embodiments (see figures 1-3) may also be present in the tube assembly 212 in figure 4, and will not all be discussed here again. For the discussion with reference to figure 4, like features are designated with similar reference numerals preceded by 200 to distinguish the embodiments.

[0067] This embodiment largely corresponds to the embodiment from figure 3, but in this case, the further wall portions 242, 243 converge and diverge along only part of the leading and trailing sections 268, 270.

[0068] At the inlet 238 of the leading section 268, each of the further wall portions 242, 243 comprises a non-inclined planar part that extends parallel to the planar parts of the further wall portions 242, 243 in the medial section 269. The further wall portions 242, 243 may include similar non-inclined planar parts at the outlet of the trailing section (not shown). The planar parts facilitate in the positioning and aligning of vertically adjacent tube rows 232, and provide larger surfaces along which the tube rows can be connected.

[0069] Figure 4 illustrates that plate structures 274 may also be arranged in between adjacent pairs of tubes 230, which also serve to promote local turbulence 264 in the second fluid flow 228 that passes the outer wall surfaces 244. Further details on these plate structures 274 are discussed below with reference to figures 5a-b and 6.

[0070] Intermediate spacers 272 may be provided inside the second fluid channels 224, and extending between adjacent tube rows 232. Such intermediate spacers 272 have lower ends that abut outer surfaces 244 of upper further tube wall portions 242, and upper ends that abut outer surfaces 245 of lower further wall portions 243 of above-lying tubes. The intermediate spacers 272 keep the tube rows 232 mutually spaced in the third direction Z, so that a relatively uniform height ΔZ2 of the second fluid channels 224 is maintained along the length of the tubes 230. In this example, the intermediate spacers are plate spacers 272, each being formed by a plate that is relatively thin (e.g. in the order of millimeters) in the first direction X, elongated along the second direction Y to extend across a plurality of tubes 230 (e.g. five to ten tubes), and having a height in the third direction Z that approximately equals the channel height ΔZ2. Only two intermediate plate spacers 272b, 272c are shown in figure 4 for illustration purposes. Each plate spacer 272 is mechanically attached via a welding line 273b, 273c to the upper further wall portion 242b2, 242c2 of the corresponding tube 230b2, 230c2, and extends along neighboring tubes 230b, 230c in the same tube row 232b, 232c to be supported by the respective further wall portions 242b, 242c, without being permanently attached thereto. It should be understood that the number and distribution of intermediate spacers 272 may be varied within one second channel 224 and/or in any or all of the other second channels 224, to maintain desired spacing of the tubes within the second fluid channels 224. Preferably, the intermediate spacers 272 in vertically adjacent second channels 224 are lined up along the third direction Z.

[0071] The above plate spacers and line welding technique and/or other intermediate spacer designs (e.g. pin spacers) and attachment techniques known in the art may employed in all tube assembly embodiments described herein.

[0072] In the exemplary tube assembly 212 of figure 4, first groups of tubes in each tube row 232 provide passage to a first fluid 226, and second groups of tubes in each tube row provide passage to a further fluid 227 that has different physical properties than the first fluid 226. As schematically indicated, the first group in the first tube row 232a may include i.a. tube 230a1, and the second group in the first tube row 232a may include i.a. tube 230a2. (Additional tubes 230 may be present, but these are not shown in the figures).

[0073] For vertically adjacent tube rows 232a, 232b, 232c, the first groups associated with the first fluid 226 (not shaded in figure 4) and the second groups associated with the further fluid 227 (shaded in figure 4) may for instance be arranged in a staggered pattern along the second direction Y. The HE device may be provided with a supply manifold (not shown) that is fluidly coupled to an inlet side 238 of the tube assembly 212, and which is configured to convey the first and further fluids 226, 227 towards and into the flow passages 236 of corresponding first and second groups of tubes 230. Alternatively or in addition, the HE device may be provided with a discharge manifold (not shown) that is fluidly coupled to an outlet side of the tube assembly 212, and which is configured to convey the first and further fluids 226, 227 out of and away from the flow passages 236 of corresponding first and second groups of tubes.

[0074] Figures 5a-5b show yet another embodiment of a tube assembly 312. Features that have been described in preceding embodiments may also be present in the tube assembly 312 and will not all be discussed here again. Like features have similar reference numerals, but preceded by 300.

[0075] This tube assembly 312 comprises grooves 362, 363 as well as plate structures 374 for locally generating small scale turbulences 364, 365 in the second fluid flows 328 that pass along the further wall portions 342, 343 when the tube-type HE device is in operation. The distribution of plates 374 and grooves 362, 363 may be varied to balance between optimal heat transfer performance (i.e. plates/grooves between each pair of tubes) and spatial compactness (i.e. no plates/grooves between any pair of tubes). For instance, one may conceive an alternating pattern with a plate/groove between two tubes followed by no plate/groove between the next tubes in the same row, and/or a pattern of plates/grooves on one side of the second fluid channel that is staggered relative to the pattern on the opposite side of the second fluid channel.

[0076] The plate structures 374 are interposed between two tubes 330, and fixed to the tubes 330 via a known welding technique e.g. electric resistance welding. Each plate structure 374 extends in the first direction X along the two bordering tubes 330, and protrudes with a first height profile F1 and/or a second height profile F2 in the third direction Z relative to the upper and/or lower further tube wall portion 342, 343 into the corresponding second fluid channel 324. The protruding plate portions 376, 377 may extend perpendicular to the further wall portions 342-343, or may be tilted at an angle α in a range 0° < α < 180° relative to the further wall portions 342-343. For instance, exemplary plate structure 374b protrudes at α = 90° in both positive and negative third directions ±Z relative to both further wall portions 342b, 343b into the second fluid channels 324 on both sides of the tube row 332b.

[0077] As shown in figure 5a, the wall 334 of each tube 330 has a substantially uniform thickness Dt of about 1.5 millimeters. In this example, the plate structures 374 have a thickness Dp that is about 0.2 millimeters (i.e. smaller than the wall thickness Dt).

[0078] Each of the rectangular tubes 330 has a tube width ΔY1 along the second direction Y and a tube height ΔZ1 along the third direction Z. In this example, a ratio of ΔY1 to ΔZ1 ranges between 2 and 3. The second channel 324 has a height ΔZ2 along the third direction Z, which is comparable to the tube height ΔZ1. (Figure 5a shows a channel height ΔZ2 that is larger than the tube height ΔZ1, only for illustration purposes). Plate structures 374 protrude along the third direction ±Z with heights ΔZp relative to the outer surfaces 344, 345 of further tube wall portions 342, 343, which heights ΔZp are about 10% of the second channel height ΔZ2.

[0079] Figure 5b shows a cross-section of a plate structure 374 in a downstream view along the second direction Y. The plate structure 374 extends in the first direction X along essentially the entire length of the tubes 330, and has upper and lower protrusions 376, 377 relative to both upper and lower further wall portions 342, 343, to define profiles F1, F2 that vary in height as a function of position along the first direction X. In this exemplary plate structure 374, the height profiles F1, F2 alternate between constant low values that are level with the outer surface 344/345 of the tube 330, and constant extreme values that protrude with respective heights ΔZp1/ΔZp2 relative to the outer surface 344/345, thus forming rectangular teeth patterns. The resulting periodic height profiles F1, F2 with sharply angled edges serve to induce local flow turbulences along both XY- and YZ planes and with a periodic pattern along the channel width, to efficiently promote laminar-to-turbulent transitions in the second fluid flows 328 near the further wall portions 342, 343. Other plate structures 374 in the tube assembly 312 may have different height profiles. In figure 5b, the protrusions 376, 377 on both sides of the structure 374 are vertically aligned, and the periodicities of the protrusions 376, 377 on plate structures 374 in adjacent tube rows 330 are essentially identical and in phase. As a result, the sequence of local vertical constrictions will be periodic and symmetric on both sides of the second fluid channel 324.

[0080] Figure 5b also schematically shows localized welding regions 378a, 378b, which are provided along and centered on a nominal centerline of the plate structure 374. This centerline extends along the first direction X, and forms a mirror or rotational symmetry axis of the plate structure 374 relative to the third direction Z. In this example, the plate structure 374 is fixed in these welding regions 378 to its two enclosing tubes via electric resistance welding.

[0081] Figure 6 shows a cross-sectional view downstream along the first direction X of yet another embodiment of a tube assembly 412. Features in embodiments described above may also be present in the tube assembly 412 and will not all be discussed here again. Like features are designated with similar reference numerals preceded by 400.

[0082] In this example, the bounding wall 434 of each tube 430 forms a unitary structure. Each lateral wall portion 440 or 441 extends on both its opposite edge regions via a curved edge portion 466, 467 into a respective one of the further wall portions 442 or 443, to form a tubular geometry with rounded edges. The curved edge portions of two adjacent tubes 430 jointly define a groove 462 or 463 that extends along the first direction X, and which is recessed along the third direction Z relative to the further wall portions 442 or 443. These grooves 462 or 463 are adapted to generate local turbulences 464, 465 in the second fluid flows 428 that pass along the further wall portions 442 or 443 when the tube-type HE device is operational. These local turbulences 464, 465 will break the boundary layer in the second fluid flow 428, and improve the attachment of the flow to the further tube wall portions 442-443, to enhance the heat transfer efficiency.

[0083] The curvature of the edge portions 466, 467 can be chosen differently, to change the intensity and characteristics of the generated local turbulences 464, 465. In this example, grooves 462, 463 are formed on both sides of the tube row 432 and between each pair of tubes 430. Other patterns of tubes and grooves may be conceived, though.

[0084] In addition, the upper and lower further wall portions 442, 443 of the tubes 430 comprise upper and lower medial wall regions 480, 481 that are displaced away from the nominal axis A and along the third direction Z, to define a local widening of the flow passage 436 relative to the lateral wall portions 440, 441 and a local narrowing of the second fluid channel 424. The tubes 430 have a tube height ΔZ1 near the lateral wall portions 440, 441, and the second channel 424 has a height ΔZ2 along the third direction Z. At the upper and lower medial wall regions 480-481, the tubes 430 have a height ΔZ3 > ΔZ1, and the second channel 424 has a height ΔZ4 < ΔZ2. A ratio of ΔZ2 to ΔZ4 is preferably larger than zero but smaller than 1.2, to avoid flow recirculation zones in the expanded part of the second channel 424. The local deformations of the medial wall regions 480-481 confer upon the second fluid channel 424 a periodically undulated shape with a symmetric unit cell, for which the height alternates as function of position along the second direction Y. This resulting periodic local narrowing of the second fluid channel 424 imparts a pulsating effect on the second fluid flow 428 (via Bernoulli's principle) between the turbulence trigger points near the grooves 462, 463. The resulting agitation of the flow yields a higher turbulence level even at low Reynolds numbers (down to Re ≈ 500), thus enhancing the heat transfer efficiency.

[0085] The resulting cross-sectional shape of the tubes 430 perpendicular to the first direction X is gradually and smoothly curved and has two inflections points around the medial wall region 480, 481. The local slope of the further wall portions 442, 443 towards the third direction Z and relative to and away from the second direction Y may be described by a set of local angles β. The angle β preferably stays within a range of -4° ≤ β ≤ +4° to ensure that the wall curvature remains smooth and relatively small, and to prevent flow separation effects in the second fluid flow 428. The smoothly curved tube converges towards an elliptical shape, thereby reducing the flow resistance for the first fluid flow 426 inside the flow passages 436 and the pressure drop in the first fluid flow 426 across the tubes 430.

[0086] For embodiments wherein the bounding tube walls 434 are formed of stainless steel with a thickness Dt of up to 2 millimeters, the outward displacement of the upper and lower medial wall regions 480, 481 away from the nominal axis A along Z and local widening of the flow passage 436 may be obtained by initially deforming a plurality of individual semi-finished tubes with rectangular cross-sections, and assembling the obtained deformed tubes into a tube assembly. The semi-finished tube may initially be sealingly enclosed within inner walls of a rigid casing, such that the inner casing walls abut only the lateral wall portions 440, 441 of the tube 430, while enclosing the further wall portions 442, 443 of the tube 430 at distances of about ½·(ΔZ3 - ΔZ1) without abutting. By introducing compressed gas (e.g. air) into the flow passage 436, a substantial overpressure can be applied to the flow passage 436 relative to the region inside the inner casing that surrounds the tube 430. The resulting forces may force and thereby permanently deflect the upper and lower medial wall regions 480, 481 locally outwards from the initial tube wall shape over the available deflection distance ½·(ΔZ3 -ΔZ1), until these regions abut the inner casing walls. For embodiments wherein the bounding walls 434 of the tubes 430 are formed of stainless steel with a thickness Dt of 2 millimeters or more, the outward displacement of the upper and lower medial wall regions 480, 481 may be obtained by subjecting the tube 430 to an overpressure inside the flow passage 436 using hydraulic pressurization techniques.

[0087] Figure 7 shows a cross-sectional view downstream along the first direction X of yet another embodiment of a tube assembly 512. Features of embodiments described above may also be present in this tube assembly 512 and will not all be discussed here again. Like features are designated with similar reference numerals preceded by 500.

[0088] Again, the upper and lower medial wall regions 580, 581 of the upper and lower further tube wall portions 542, 543 are displaced away from the nominal axis A and along the third direction Z, to define a local widening of the flow passage 536 relative to the lateral wall portions 540, 541 and a local narrowing of the second fluid channel 524. In this example, the tube deformation is asymmetric relative to the nominal tube axis A and along second direction Y. In particular, the maximum deflection of the medial wall regions 580, 581 of each tube 530 is located on a lateral side of the nominal axis A that is closer to the lateral wall portion 541 facing the incoming second fluid flow 528. In the example of figure 7, the outer wall surfaces 544, 545 of adjacent tube rows 532 on opposite sides of the second fluid channel 524 define a periodic sequence of Venturi-shaped profiles. The outer wall surfaces 544, 545 in an individual Venturi-profile first converges and then diverges in the third direction Z as function of position along the second direction Y. As a result, the incoming second fluid flow 528 first traverses a bell mouth shaped narrowing of the second channel 524 to a locally reduced height ΔZ4, which causes the flow velocity in the second flow 528 to increase. Beyond the narrow portion of the second channel 524 at the crests of medial wall regions 580, 581, the second channel 524 widens again in an approximately linear fashion, to finish at an increased channel height ΔZ2 at the end of the individual Venturi profile. The extent of narrowing and widening is drawn in an exaggerated manner in figure 7. In reality, the ratio of ΔZ2 to ΔZ4 preferably is larger than zero but smaller than 1.2. In addition, the subsequent widening of the respective wall surface 544, 545 is preferably oriented at an (half) angle β in a range of -4° ≤ β ≤ +4° away from the second direction Y, to ensure that a pressure drop in the second fluid flow 528 remains minimal.

[0089] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description.

[0090] Note that for reasons of conciseness, the reference numbers corresponding to similar elements in the various embodiments (e.g. elements 112, 212 being similar to element 12) have been collectively indicated in the claims by their base numbers only i.e. without the multiples of hundreds. However, this does not suggest that the claim elements should be construed as referring only to features corresponding to base numbers. Although the similar reference numbers have been omitted in the claims, their applicability will be apparent from a comparison with the figures.

[0091] It will be apparent to the person skilled in the art that alternative and equivalent embodiments of the invention can be conceived and reduced to practice. For instance, features from the above-described exemplary embodiments may be combined to form other embodiments. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[0092] In the above exemplary embodiments, the channel heights ΔZ1, ΔZ2 of the first and second fluid channels were described as approximately equal, merely for illustration purposes. The use of a tube assembly wherein the first fluid channels (i.e. the flow passage inside each tube) and second fluid channels (i.e. the space between vertically adjacent tubes) have similar heights (i.e. ΔZ1 ≈ ΔZ2) may be preferred in HE applications wherein the first and second fluids are both gasses with comparable pressure and low saturation. In HE applications wherein the second fluid is a low- or non-pressurized unsaturated gas and wherein the first fluid is a pressurized and saturated vapor with diffused liquid substance that is to condense on the inner walls of the tubes when passing through the flow passages, a tube assembly may be preferred wherein the second fluid channels are at least an order of magnitude larger than the first fluid channels (i.e. ΔZ2 ≥ 10·ΔZ1 e.g. ΔZ2 ≈ 20·ΔZ1).

[0093] In the plate structure 370 described in figure 5b, the protrusions 376, 377 on both sides of the structure were vertically aligned and the periodicities of the protrusions on plate structures in adjacent tube rows were essentially identical and in phase. However, in alternative embodiments, the periodicity of the protrusions in adjacent tube rows may be identical, but may be shifted in phase along the first direction X, for instance over half the spatial period. Such half-phase offset between protrusions on both sides of a second fluid channel ensures that the crests in the first height profile on one vertical side of a second fluid channel will coincide with the troughs of the second height profile on the other side of the same second fluid channel, to create a second fluid channel with an effective height that stays essentially constant along the first direction X. The resulting fluid flow and turbulence effects within the second channel may thus stay relatively uniform along X. The shape of the protrusions may be similar or different, within the same height profile on one side of a single plate structure, and/or between the first and second height profiles on both sides of the same plate structure, and/or between adjacent plate structures on both sides of the same second fluid channel.

[0094] In addition, the technical features disclosed herein are not restricted to the exemplary cross-flow plate-type HE device and tube arrangements described above, but may also be applied to other heat exchanger types, for example based on concurrent flow or counter flow principles and/or having Z-type or U-type configurations. For instance, the tubes in the above-described exemplary embodiments were substantially linear in shape, and extended predominantly along the first direction X. In alternative embodiments, it is possible for the tubes to curve away as function along the flow trajectory of the first fluid through the tubes. In these cases, the three directions X, Y, Z should be considered local spatial properties, which vary with position along the flow trajectory. The tube rows may for instance have a Z-shape, U-type, or undulated shape. The shapes of the second fluid channels may also be varied along the flow path of the second fluid, to form macroscopically curved configurations, for instance of the Z-type, or U-type. Alternatively or in addition, the cross-sectional shape of the entire tube arrangement may deviate from a uniform rectangular shape, by varying widths of distinct tube rows as function along the third direction, and/or by using spacer members with outer lateral surfaces that interpolatingly interconnect the mutually displaced tube edges of above- and below-situated tube rows.

[0095] It will also be appreciated that the tubes may be formed of different materials than metal. The tubes may for instance consist essentially of metal alloys, a ceramics, glass, glass coated metals, or glass coated metal alloys. Different materials may be selected for distinct tubes and/or for distinct tube rows, depending on the mechanical and thermal requirements of the resulting HE device.

[0096] It should also be understood that the tubes may have other cross-sectional shapes, provided that the lateral tube wall portions have complementary outer surfaces that allow adjacent tubes to adjoin and interconnect to form a tube row. Preferably, the lateral tube wall portions are flat. The tubes may for instance have quadrilateral cross-sectional shapes e.g. rectangular (e.g. square), rhomboidal (e.g. diamond), trapezoidal, or parallelogram shapes. The cross-sectional shapes of distinct tubes may be identical or different.

[0097] In the majority of above-described examples, the flow passages of the tubes in each tube row jointly formed one first fluid channel to provide passage to the same first fluid with initial physical properties (e.g. composition, pressure, temperature, velocity, etc.). It should be understood that in alternative embodiments, the adjacent flow passages of tubes in one tube row may provide passage to distinct fluids with different composition, pressure, temperature, and/or velocity characteristics. For instance, a first selection of the tubes in this row may provide passage to the first fluid, and a further (i.e. distinct) selection of the tubes in this row may provide passage to a further fluid with different composition, pressure, temperature, and/or velocity characteristics. The HE device may be provided with fluid supply and/or discharge manifolds that are configured to convey the distinct fluid flows towards and/or away from their corresponding flow passages through the tube assembly.

[0098] Furthermore, the above-described concepts do not only pertain to tube-type HE devices of a unitary kind, i.e. a single tube assembly mounted in a single frame with connections for incoming and outgoing fluid streams. It should be understood that a multitude of HE units - of similar or diverse configurations as described herein and/or in combination with known HE unit types (e.g. shell-and-tube-type HE units, plate-type HE units, etc.) - may be combined to create large HE networks, without any limitation in size or operating performance and for a large diversity of industrial applications.

List of Reference Symbols

[0099] Similar reference numbers that have been used in the description to indicate similar elements (but differing only in the hundreds) have been omitted from the list below, but should be considered implicitly included.

10

heat exchanger device

12

tube assembly

14

heat exchanger frame

16

support member

17

connection region

18

end panel

20

sealing means

22

first fluid channel

24

second fluid channel

26

first fluid flow

28

second fluid flow

30

tube

32

tube row

34

bounding wall

36

flow passage

38

inlet

39

outlet

40

lateral wall portion

41

lateral wall portion

42

further wall portion

43

further wall portion

44

outer wall surface

45

outer wall surface

46

leading lateral edge

47

leading lateral edge

48

leading further edge

49

leading further edge

50

trailing lateral edge

51

trailing lateral edge

52

trailing further edge

53

trailing further edge

54

leading spacer (e.g. rectangular bar)

55

trailing spacer (e.g. rectangular bar)

56

leading surface (of leading spacer)

57

trailing surface (of trailing spacer)

58

weld line

59

weld line

60

further weld line

61

further weld line

62

groove

63

groove

64

local turbulence

65

local turbulence

66

edge portion

67

edge portion

168

leading tube section

169

medial tube section

170

trailing tube section

227

further fluid flow

272

intermediate spacer (e.g. plate spacer)

273

spacer connection

274

plate structure

374

plate structure

376

protrusion

377

protrusion

378

plate welding region

480

medial wall region

481

medial wall region

X

first direction (e.g. longitudinal direction)

Y

second direction (e.g. transversal direction)

Z

third direction (e.g. vertical direction)

F1

first height profile

F2

second height profile

A

nominal tube axis

Dt

thickness (of tube wall)

Dp

thickness (of plate structure)

ΔY1

tube width

ΔZ1

tube height

ΔZ2

second channel height

ΔZ3

widened tube height

ΔZ4

reduced second channel height

ΔZg

groove depth

ΔZp(i)

maximum protrusion height (of i^th height profile)

Claims

1. A tube assembly (412) for a tube-type heat exchanger, HE, device, wherein the tube assembly comprises a plurality of tubes (430), wherein each tube is formed by a bounding wall (434) that surrounds a flow passage (436) along a nominal axis (A) in a first direction (X), the bounding wall having two lateral wall portions (440, 441) on opposite sides along the flow passage, and two further wall portions (442, 443) on further opposite sides along the flow passage;

wherein the tubes are adjacently arranged into tube rows (432a, 432b) that co-extend along the first direction (X) to define first fluid channels the tube rows being mutually spaced along a third direction (Z) to define second fluid channels (424a) between adjacent pairs of tube rows (432);

wherein at least one tube row (432) is formed of tubes (430a2, 430a3) that are consecutively arranged along a second direction (Y), so that the lateral wall portions (440, 441) of the tubes adjoin, and that the further wall portions (442, 443) of the tubes jointly define outer surfaces (445) that border respective second fluid channels (424);

characterized in that the further wall portions (442, 443) of the tubes (430) in the at least one row (432) comprise medial wall regions (480) that are displaced along the third direction (Z) and away from the nominal axis (A), to define local widenings of the flow passages (436) relative to the lateral wall portions (440, 441) and local narrowings of the second fluid channel (424) in order to confer an undulated shape upon the outer surfaces (444, 445) bordering the second fluid channel.

2. The tube assembly according to claim 1, wherein the tubes in the tube row extend transversely to an associated second fluid channel, wherein at least two of the outer surfaces are interrupted by a level variation in the third direction (Z), the level variation extending in the first direction (X) along a boundary line between two directly adjacent tubes, the level variation being formed by at least one plate structure (374) that is fixed to and interposed between the adjacent tubes, the plate structure protruding along the third direction (Z) with a height (ΔZp) relative to at least one of the outer surfaces and being adapted to generate local turbulence in the second fluid flow that passes predominantly in the second direction (Y) through the second fluid channel and across the outer surfaces and the level variation, when the tube-type HE device is in operation.

3. The tube assembly (312) according to claim 2, wherein the plate structure (374) protrudes along the third direction (Z) with a height (ΔZp) relative to at least one of the outer surfaces (344, 345) of the further tube wall portions (342, 343), the height being in a range between 10% and 20% of a height (ΔZ2) of the respective second fluid channel (324) in order to generate the local turbulence (364, 365) in the second fluid flow (328).

4. The tube assembly (312) according to claim 3, wherein the plate structure (374) extends in the first direction (X) along essentially the entire length of the tubes (330), and protrudes relative to the at least one of the outer surfaces (344, 345) of the further wall portions (342, 343) to define a height profile (F1, F2) along the third direction (Z) that varies with position along the first direction (X).

5. The tube assembly (312) according to claim 4, wherein the height profile (F1, F2) varies in an alternating manner along the third direction (Z) with position along the first direction (X), wherein the height profile preferably defines a sequence of edges that are mutually oriented at non-zero angles to define sharp corners, and for instance forms a polygonal height profile.

6. The tube assembly (312) according to any one of claims 2-5, wherein the plate structure (374) protrudes bi-directionally along the third direction (Z) relative to both the outer surfaces (344, 345) of the further wall portions (342, 343) into part of the second fluid channels (324) on both sides of the at least one tube row (332).

7. The tube assembly (512) according to any one of claims 1-6, wherein the further wall portions (544, 545) have displaced medial wall regions (580, 581) such that outer wall surfaces (544, 545) of pairs of tubes (530) from directly adjacent tube rows (532) on opposite sides of the second fluid channel (524) define a periodic sequence of Venturi profiles, viewed in a cross-section along the second and third directions (Y, Z).

8. The tube assembly (12) according to any one of claims 1-7, wherein the tubes (30) are mutually fixed via weld lines (58, 59) that extend along lateral edges (46, 47, 50, 51) of the respective lateral wall portions (40, 41) of the tubes;
and wherein the lateral edges are leading lateral edges (46, 47) located at inlets (38) of the flow passages (36), or trailing lateral edges (50, 51) located at outlets (39) of the flow passages, or both.

9. The tube assembly (12) according to any one of claims 1-8, comprising spacers (54, 55) that extend in the second flow direction (Y) and along the further wall portions (42, 43) of the tubes to provide non-zero mutual spacing between the tube rows (32) along the third direction (Z), wherein the spacers include at least one of:

leading spacers (54) located at or near leading further edges (48, 49) of the further wall portions (42, 43) at inlets (38) of the flow passages (36), and

trailing spacers (55) located at or near trailing further edges (52, 53) of the further wall portions at outlets (39) of the flow passages;

the tube assembly additionally comprising a further tube row (32b) formed of tubes (30b1, 30b2, 30b3) that are consecutively arranged along the second direction (Y), wherein the further tube row is adjacent to the at least one row (32a) and aligned therewith relative to the second direction (Y) so that lateral wall portions (40, 41) of the tubes (30) in the adjacent tube rows line up in the third direction (Z);

and wherein weld lines (58, 59) form continuous weld lines that extend along consecutive adjacent lateral edges (46, 47, 50, 51) of the lateral wall portions (40, 41) as well as across the spacers (54, 55).

10. The tube assembly (12) according to claim 9, wherein the tubes (30) in the at least one tube row (32) are fixed to an adjacent leading spacer (54) via a further weld line (60) along the leading further edges (48, 49) of the tubes and a leading surface (56) of the leading spacer, or to an adjacent trailing spacer (55) via a further weld line (61) along the trailing further edges (52, 53) of the tubes and a trailing surface (57) of the trailing spacer, or both.

11. The tube assembly (112) according to any one of claims 1-8, wherein each of the tubes (130) comprises a leading section (168) extending along the respective flow passage (136) from a respective inlet (138), a trailing section (170) extending along the flow passage from a respective outlet (139), and a medial section (169) extending along the flow passage between the leading and trailing sections;

wherein, within the leading section, at least one of the further wall portions (142, 143) of the tubes converges along the third direction (Z) towards the nominal axis (A), so that the flow passage (136) narrows with position along the first direction (X);

or wherein, within the trailing section, at least one of the further wall portions of the tubes diverges along the third direction away from the nominal axis, so that the flow passage widens with position along the first direction, or both.

12. The tube assembly (112) according to claim 11, wherein adjacent tube rows (132a, 132b, 132c) adjoin along leading further edges (148, 149) of the further wall portions (142, 143) of the tubes (130) located at inlets (138) of the flow passages (136), or adjoin along trailing further edges (152, 153) of the further wall portions located at outlets (139) of the flow passages, or both;

wherein the adjacent tube rows are mutually spaced in the third direction (Z) throughout the medial sections (169) to delimit the second fluid channels (124);

and wherein the adjacent tube rows (132) are mutually fixed via continuous further weld lines (160) along the leading further edges (148, 149), or via continuous further weld lines (161) along the trailing further edges (152, 153), or both.

13. The tube assembly (12) according to any one of claims 1-12, wherein the bounding wall (34) of each tube (30) forms a continuous unitary wall, having a substantially uniform thickness (Dt) in directions perpendicular to the first direction (X),
optionally wherein each lateral wall portion (40, 41) has a cross-sectional shape forming a convex curve, or wherein the bounding wall (34) of each tube (30) has a cross-sectional shape forming a closed convex curve.

14. The tube assembly (12) according to any one of claims 1-13, wherein the bounding wall (34) of each tube (30) has a substantially quadrilateral cross-sectional shape, preferably a substantially rectangular cross-sectional shape, in planes perpendicular to the first direction (X).

15. The tube assembly (12) according to any one of claims 1-14, wherein each of the tubes (30) is formed from a semi-finished tube that consists essentially of metal or metal alloy, of which one or more surfaces are coated with a glass layer prior to arranging the tubes into the tube rows (32), or wherein each of the tubes (30) consists essentially of a metal, a metal alloy, a ceramic, or a glass.

16. A tube-type heat exchanger, HE, device (10), comprising:

- a frame (14), and

- a tube assembly (212) according to any one of claims 1-15, mounted on an inner side of the frame;
optionally wherein a first group (230a1) of tubes in one tube row (232a) provides passage to the first fluid (226), and a second group (230a2) of tubes in the one tube row (232a) provides passage to a further fluid (227) that differs from the first fluid.

Ansprüche

1. Rohranordnung (412) für eine Rohrtypwärmetauscher Vorrichtung, wobei die Rohranordnung eine Vielzahl von Rohren (430) umfasst, wobei jedes Rohr durch eine Begrenzungswand (434) ausgebildet ist, die einen Strömungsdurchgang (436) entlang einer Nennachse (A) in einer ersten Richtung (X) umgibt, wobei die Begrenzungswand zwei Seitenwandabschnitte (440, 441) auf gegenüberliegenden Seiten entlang des Strömungsdurchgangs und zwei weitere Wandabschnitte (442, 443) auf weiteren gegenüberliegenden Seiten entlang des Strömungsdurchgangs aufweist,

wobei die Rohre in Rohrreihen (432a, 432b) angrenzend eingerichtet sind, die sich entlang der ersten Richtung (X) gemeinsam erstrecken, um erste Fluidkanäle zu definieren, wobei die Rohrreihen entlang einer dritten Richtung (Z) voneinander beabstandet sind, um zweite Fluidkanäle (424a) zwischen angrenzenden Paaren von Rohrreihen (432) zu definieren,

wobei mindestens eine Rohrreihe (432) aus Rohren (430a2, 430a3) ausgebildet ist, die entlang einer zweiten Richtung (Y) aufeinanderfolgend eingerichtet sind, so dass die Seitenwandabschnitte (440, 441) der Rohre aneinandergrenzen, und dass die weiteren Wandabschnitte (442, 443) der Rohre zusammen Außenoberflächen (445) definieren, die jeweilige zweite Fluidkanäle (424) umranden;

dadurch gekennzeichnet, dass die weiteren Wandabschnitte (442, 443) der Rohre (430) in der mindestens einen Reihe (432) mittlere Wandregionen (480) umfassen, die entlang der dritten Richtung (Z) und weg von der Nennachse (A) versetzt sind, um örtliche Erweiterungen der Strömungsdurchgänge (436) relativ zu den Seitenwandabschnitten (440, 441) und örtliche Verengungen des zweiten Fluidkanals (424) zu definieren, um den Außenoberflächen (444, 445) eine gewellte Form zu verleihen, die den zweiten Fluidkanal umranden.

2. Rohranordnung nach Anspruch 1, wobei sich die Rohre in der Rohrreihe quer zu einem zugeordneten zweiten Fluidkanal erstrecken, wobei mindestens zwei der Außenoberflächen durch eine Ebenenvariation in der dritten Richtung (Z) unterbrochen sind, wobei sich die Ebenenvariation in der ersten Richtung (X) entlang einer Grenzlinie zwischen zwei unmittelbar angrenzenden Rohren erstreckt, wobei die Ebenenvariation durch mindestens eine Plattenstruktur (374) ausgebildet wird, die an den angrenzenden Rohren befestigt und zwischen diesen eingefügt ist, wobei die Plattenstruktur entlang der dritten Richtung (Z) mit einer Höhe (ΔZp) relativ zu mindestens einer der Außenoberflächen vorsteht und angepasst ist, um lokale Turbulenzen in der zweiten Fluidströmung zu erzeugen, die überwiegend in der zweiten Richtung (Y) durch den zweiten Fluidkanal hindurch und über die Außenoberflächen und die Ebenenvariation hinweg verläuft, wenn die Rohrtypwärmetauscher Vorrichtung in Betrieb ist.

3. Rohranordnung (312) nach Anspruch 2, wobei die Plattenstruktur (374) entlang der dritten Richtung (Z) mit einer Höhe (ΔZp) relativ zu mindestens einer der Außenoberflächen (344, 345) der weiteren Rohrwandabschnitte (342, 343) vorsteht, wobei die Höhe in einem Bereich zwischen 10 % und 20 % einer Höhe (ΔZ2) des jeweiligen zweiten Fluidkanals (324) liegt, um die lokale Turbulenz (364, 365) in dem zweiten Fluidstrom (328) zu erzeugen.

4. Rohranordnung (312) nach Anspruch 3, wobei sich die Plattenstruktur (374) in der ersten Richtung (X) entlang im Grunde der gesamten Länge der Rohre (330) erstreckt und relativ zu mindestens einer der Außenoberflächen (344, 345) der weiteren Wandabschnitte (342, 343) vorsteht, um ein Höhenprofil (F1, F2) entlang der dritten Richtung (Z) zu definieren, das mit der Position entlang der ersten Richtung (X) variiert.

5. Rohranordnung (312) nach Anspruch 4, wobei das Höhenprofil (F1, F2) entlang der dritten Richtung (Z) auf eine alternierende Weise mit der Position entlang der ersten Richtung (X) variiert, wobei das Höhenprofil vorzugsweise eine Abfolge von Kanten definiert, die in Winkeln ungleich Null zueinander orientiert sind, um scharfe Ecken zu definieren, und beispielsweise ein polygonales Höhenprofil ausbildet.

6. Rohranordnung (312) nach einem der Ansprüche 2 bis 5, wobei die Plattenstruktur (374) in zwei Richtungen entlang der dritten Richtung (Z) relativ zu beiden der Außenoberflächen (344, 345) der weiteren Wandabschnitte (342, 343) in einen Teil der zweiten Fluidkanäle (324) auf beiden Seiten der mindestens einen Rohrreihe (332) vorsteht.

7. Rohranordnung (512) nach einem der Ansprüche 1 bis 6, wobei die weiteren Wandabschnitte (544, 545) versetzte mittlere Wandregionen (580, 581) derart aufweisen, dass äußere Wandoberflächen (544, 545) von Paaren von Rohren (530) von unmittelbar angrenzenden Rohrreihen (532) auf gegenüberliegenden Seiten des zweiten Fluidkanals (524) eine periodische Abfolge von Venturi-Profilen definieren, in einem Querschnitt entlang der zweiten und dritten Richtung (Y, Z) betrachtet.

8. Rohranordnung (12) nach einem der Ansprüche 1 bis 7, wobei die Rohre (30) über Schweißlinien (58, 59) zueinander befestigt sind, die sich entlang Seitenkanten (46, 47, 50, 51) der jeweiligen Seitenwandabschnitte (40, 41) der Rohre erstrecken,
und wobei die Seitenkanten vordere Seitenkanten (46, 47), die sich an Einlässen (38) der Strömungsdurchgänge (36) befinden, oder hintere Seitenkanten (50, 51), die sich an Auslässen (39) der Strömungsdurchgänge befinden, oder beides sind.

9. Rohranordnung (12) nach einem der Ansprüche 1 bis 8, umfassend Abstandshalter (54, 55), die sich in der zweiten Strömungsrichtung (Y) und entlang der weiteren Wandabschnitte (42, 43) der Rohre erstrecken, um gegenseitigen Abstand ungleich Null zwischen den Rohrreihen (32) entlang der dritten Richtung (Z) bereitzustellen, wobei die Abstandshalter mindestens eines beinhalten von:

vordere Abstandshalter (54), die sich an oder in der Nähe vorderer weiterer Kanten (48, 49) der weiteren Wandabschnitte (42, 43) an Einlässen (38) der Strömungsdurchgänge (36) befinden, und

hintere Abstandshalter (55), die sich an oder nahe hinterer weiterer Kanten (52, 53) der weiteren Wandabschnitte an Auslässen (39) der Strömungsdurchgänge befinden,

die Rohranordnung umfassend zusätzlich eine weitere Rohrreihe (32b), die aus Rohren (30b1, 30b2, 30b3) ausgebildet ist, die entlang der zweiten Richtung (Y) aufeinanderfolgend eingerichtet sind, wobei die weitere Rohrreihe an die mindestens eine Reihe (32a) angrenzt und damit relativ an der zweiten Richtung (Y) ausgerichtet ist, so dass Seitenwandabschnitte (40, 41) der Rohre (30) in den angrenzenden Rohrreihen in der dritten Richtung (Z) aufgestellt sind,

und wobei die Schweißlinie (58, 59) kontinuierliche Schweißlinien ausbilden, die sich entlang aufeinanderfolgender angrenzender Seitenränder (46, 47, 50, 51) der Seitenwandabschnitte (40, 41) sowie über die Abstandshalter (54, 55) hinweg erstrecken.

10. Rohranordnung (12) nach Anspruch 9, wobei die Rohre (30) in der mindestens einen Rohrreihe (32) an einem angrenzenden vorderen Abstandshalter (54) über eine weitere Schweißlinie (60) entlang der vorderen weiteren Kanten (48, 49) der Rohre und einer vorderen Oberfläche (56) des vorderen Abstandshalters oder an einem angrenzenden hinteren Abstandshalter (55) über eine weitere Schweißlinie (61) entlang der hinteren weiteren Kanten (52, 53) der Rohre und einer hinteren Oberfläche (57) des hinteren Abstandshalters oder beidem befestigt sind.

11. Rohranordnung (112) nach einem der Ansprüche 1 bis 8, wobei jedes der Rohre (130) einen vorderen Abschnitt (168), der sich entlang des jeweiligen Strömungsdurchgangs (136) von einem jeweiligen Einlass (138) erstreckt, einen hinteren Abschnitt (170), der sich entlang des Strömungsdurchgangs von einem jeweiligen Auslass (139) erstreckt, und einen mittleren Abschnitt (169) umfasst, der sich entlang des Strömungsdurchgangs zwischen dem vorderen und dem hinteren Abschnitt erstreckt,

wobei, innerhalb des vorderen Abschnitts, mindestens einer der weiteren Wandabschnitte (142, 143) der Rohre entlang der dritten Richtung (Z) zu der Nennachse (A) hin konvergiert, so dass sich der Strömungsdurchgang (136) mit der Position entlang der ersten Richtung (X) verengt;

oder wobei, innerhalb des hinteren Abschnitts, mindestens einer der weiteren Wandabschnitte der Rohre entlang der dritten Richtung von der Nennachse weg divergiert, so dass sich der Strömungsdurchgang mit der Position entlang der ersten Richtung erweitert, oder beides.

12. Rohranordnung (112) nach Anspruch 11, wobei angrenzende Rohrreihen (132a, 132b, 132c) entlang vorderer weiterer Kanten (148, 149) der weiteren Wandabschnitte (142, 143) der Rohre (130) aneinandergrenzen, die sich an Einlässen (138) der Strömungsdurchgänge (136) befinden, oder entlang hinterer weiterer Kanten (152, 153) der weiteren Wandabschnitte aneinandergrenzen, die sich an Auslässen (139) der Strömungsdurchgänge befinden, oder beides;

wobei die angrenzenden Rohrreihen in der dritten Richtung (Z) im Verlauf der mittleren Abschnitte (169) voneinander beabstandet sind, um die zweiten Fluidkanäle (124) abzugrenzen;

und wobei die angrenzenden Rohrreihen (132) über kontinuierliche weitere Schweißlinien (160) entlang der vorderen weiteren Kanten (148, 149) oder über kontinuierliche weitere Schweißlinien (161) entlang der hinteren weiteren Kanten (152, 153) zueinander befestigt sind, oder beide.

13. Rohranordnung (12) nach einem der Ansprüche 1 bis 12, wobei die Begrenzungswand (34) jedes Rohrs (30) eine kontinuierliche einheitliche Wand ausbildet, die eine im Wesentlichen gleichmäßige Dicke (Dt) in Richtungen senkrecht zu der ersten Richtung (X) aufweist,
optional wobei jeder Seitenwandabschnitt (40, 41) eine Querschnittsform aufweist, die eine konvexe Kurve ausbildet, oder wobei die Begrenzungswand (34) jedes Rohrs (30) eine Querschnittsform aufweist, die eine geschlossene konvexe Kurve ausbildet.

14. Rohranordnung (12) nach einem der Ansprüche 1 bis 13, wobei die Begrenzungswand (34) jedes Rohrs (30) eine im Wesentlichen vierseitige Querschnittsform, vorzugsweise eine im Wesentlichen rechteckige Querschnittsform, in Ebenen senkrechten zu der ersten Richtung (X) aufweist.

15. Rohranordnung (12) nach einem der Ansprüche 1 bis 14, wobei jedes der Rohre (30) aus einem halbfertigen Rohr ausgebildet ist, das im Grunde aus Metall oder Metalllegierung besteht, wovon eine oder mehrere Oberflächen mit einer Glasschicht vor dem Einrichten der Rohre in den Rohrreihen (32) beschichtet sind, oder wobei jedes der Rohre (30) im Grunde aus einem Metall, einer Metalllegierung, einer Keramik oder einem Glas besteht.

16. Rohrtypwärmetauscher Vorrichtung (10), umfassend:

- einen Rahmen (14), und

- eine Rohranordnung (212) nach einem der Ansprüche 1 bis 15, die auf einer Innenseite des Rahmens angebracht ist,

optional wobei eine erste Gruppe (230a1) von Rohren in einer Rohrreihe (232a) einen Durchgang zu dem ersten Fluid (226) bereitstellt und eine zweite Gruppe (230a2) von Rohren in der einen Rohrreihe (232a) den Durchgang zu einem weiteren Fluid (227) bereitstellt, das sich von dem ersten Fluid unterscheidet.

Revendications

1. Ensemble tube (412) destiné à un dispositif échangeur de chaleur à tube dans lequel l'ensemble tube comprend une pluralité de tubes (430), dans lequel chaque tube est formé par une paroi de délimitation (434) qui entoure un passage d'écoulement (436) le long d'un axe nominal (A) dans une première direction (X), la paroi de délimitation ayant deux parties de paroi latérales (440, 441) sur des côtés opposés le long du passage d'écoulement, et deux autres parties de paroi (442, 443) sur d'autres côtés opposés le long du passage d'écoulement ;

dans lequel les tubes sont agencés de manière adjacente en rangées de tubes (432a, 432b) qui s'étendent conjointement le long de la première direction (X) pour définir des premiers canaux de fluide, les rangées de tubes étant mutuellement espacées le long d'une troisième direction (Z) pour définir des seconds canaux de fluide (424a) entre des paires adjacentes de rangées de tubes (432) ;

dans lequel au moins une rangée de tubes (432) est formée de tubes (430a2, 430a3) qui sont agencés consécutivement le long d'une deuxième direction (Y), de sorte que les parties de paroi latérales (440, 441) des tubes soient contiguës, et que les autres parties de paroi (442, 443) des tubes définissent conjointement des surfaces externes (445) qui bordent des seconds canaux de fluide respectifs (424) ;

caractérisé en ce que les autres parties de paroi (442, 443) des tubes (430) dans l'au moins une rangée (432) comprennent des régions de paroi médianes (480) qui sont déplacées le long de la troisième direction (Z) et éloignées de l'axe nominal (A), pour définir des élargissements locaux des passages d'écoulement (436) par rapport aux parties de paroi latérales (440, 441) et des rétrécissements locaux du second canal de fluide (424) afin de conférer une forme ondulée aux surfaces externes (444, 445) bordant le second canal fluidique.

2. Ensemble tube selon la revendication 1, dans lequel les tubes de la rangée de tubes s'étendent transversalement à un second canal de fluide associé, dans lequel au moins deux des surfaces externes sont interrompues par une variation de niveau dans la troisième direction (Z), la variation de niveau s'étendant dans la première direction (X) le long d'une ligne de démarcation entre deux tubes directement adjacents, la variation de niveau étant formée par au moins une structure de plaque (374) fixée et interposée entre les tubes adjacents, la structure de plaque faisant saillie selon la troisième direction (Z) avec une hauteur (ΔZp) par rapport à au moins une des surfaces externes et étant adaptée pour générer une turbulence locale dans le second écoulement de fluide qui passe principalement dans la seconde direction (Y) à travers le second canal de fluide et à travers les surfaces externes et la variation de niveau, lorsque le dispositif échangeur de chaleur à tube est en fonctionnement.

3. Ensemble tube (312) selon la revendication 2, dans lequel la structure de plaque (374) fait saillie le long de la troisième direction (Z) avec une hauteur (ΔZp) par rapport à au moins une des surfaces externes (344, 345) des autres parties de paroi (342, 343) de tube, la hauteur étant comprise entre 10 % et 20 % d'une hauteur (ΔZ2) du second canal de fluide respectif (324) afin de générer la turbulence locale (364, 365) dans le second écoulement de fluide (328).

4. Ensemble tube (312) selon la revendication 3, dans lequel la structure de plaque (374) s'étend dans la première direction (X) le long d'essentiellement toute la longueur des tubes (330), et fait saillie par rapport à au moins l'une des surfaces externes (344, 345) des autres parties de paroi (342, 343) pour définir un profil de hauteur (F1, F2) le long de la troisième direction (Z) qui varie avec la position le long de la première direction (X).

5. Ensemble tube (312) selon la revendication 4, dans lequel le profil de hauteur (F1, F2) varie de manière alternée le long de la troisième direction (Z) avec la position le long de la première direction (X), dans lequel le profil de hauteur définit de préférence une séquence de bords mutuellement orientés à des angles non nuls pour définir des angles vifs, et forme par exemple un profil de hauteur polygonal.

6. Ensemble tube (312) selon l'une quelconque des revendications 2 à 5, dans lequel la structure de plaque (374) fait saillie de manière bidirectionnelle le long de la troisième direction (Z) par rapport aux deux surfaces externes (344, 345) des autres parties de paroi (342, 343) dans une partie des seconds canaux de fluide (324) sur les deux côtés de l'au moins une rangée de tubes (332).

7. Ensemble tube (512) selon l'une quelconque des revendications 1 à 6, dans lequel les autres parties de paroi (544, 545) ont des régions de paroi médianes déplacées (580, 581) de sorte que les surfaces de paroi externes (544, 545) de paires de tubes (530) de rangées de tubes (532) directement adjacentes sur des côtés opposés du second canal de fluide (524) définissent une séquence périodique de profils Venturi, vus en coupe transversale le long des deuxième et troisième directions (Y, Z).

8. Ensemble tube (12) selon l'une quelconque des revendications 1 à 7, dans lequel les tubes (30) sont mutuellement fixés par l'intermédiaire de lignes de soudure (58, 59) qui s'étendent le long des bords latéraux (46, 47, 50, 51) des parties de paroi latérales respectives (40, 41) des tubes ;
et dans lequel les bords latéraux sont des bords latéraux d'attaque (46, 47) situés au niveau des entrées (38) des passages d'écoulement (36), ou des bords latéraux de fuite (50, 51) situés au niveau des sorties (39) des passages d'écoulement, ou les deux.

9. Ensemble tube (12) selon l'une quelconque des revendications 1 à 8, comprenant des entretoises (54, 55) qui s'étendent dans la seconde direction d'écoulement (Y) et le long des autres parties de paroi (42, 43) des tubes pour fournir un espacement mutuel non nul entre les rangées de tubes (32) le long de la troisième direction (Z), dans lequel les entretoises comportent au moins l'un parmi :

des entretoises d'attaque (54) situées au niveau ou à proximité d'autres bords d'attaque (48, 49) des autres parties de paroi (42, 43) au niveau des entrées (38) des passages d'écoulement (36), et

des entretoises de fuite (55) situées au niveau ou à proximité d'autres bords de fuite (52, 53) des autres parties de paroi au niveau des sorties (39) des passages d'écoulement ;

l'ensemble tube comprenant en outre une autre rangée de tubes (32b) formée de tubes (30b1, 30b2, 30b3) qui sont agencés consécutivement le long de la deuxième direction (Y), dans lequel l'autre rangée de tubes est adjacente à l'au moins une rangée (32a) et alignée avec celle-ci par rapport à la deuxième direction (Y) de sorte que les parties de paroi latérales (40, 41) des tubes (30) dans les rangées de tubes adjacentes s'alignent dans la troisième direction (Z) ;

et dans lequel les lignes de soudure (58, 59) forment des lignes de soudure continues qui s'étendent le long des bords latéraux adjacents consécutifs (46, 47, 50, 51) des parties de paroi latérales (40, 41) ainsi qu'à travers les entretoises (54, 55).

10. Ensemble tube (12) selon la revendication 9, dans lequel les tubes (30) dans l'au moins une rangée de tubes (32) sont fixés à une entretoise d'attaque adjacente (54) par l'intermédiaire d'une autre ligne de soudure (60) le long des autres bords d'attaque (48, 49) des tubes et une surface d'attaque (56) de l'entretoise d'attaque, ou à une entretoise de fuite adjacente (55) par l'intermédiaire d'une autre ligne de soudure (61) le long des autres bords de fuite (52, 53) des tubes et une surface de fuite (57) de l'entretoise de fuite, ou les deux.

11. Ensemble tube (112) selon l'une quelconque des revendications 1 à 8, dans lequel chacun des tubes (130) comprend une section d'attaque (168) s'étendant le long du passage d'écoulement respectif (136) à partir d'une entrée respective (138), une section de fuite (170) s'étendant le long du passage d'écoulement à partir d'une sortie respective (139), et une section médiane (169) s'étendant le long du passage d'écoulement entre les sections d'attaque et de fuite ;

dans lequel, à l'intérieur de la section d'attaque, au moins une des autres parties de paroi (142, 143) des tubes converge le long de la troisième direction (Z) vers l'axe nominal (A), de sorte que le passage d'écoulement (136) se rétrécit avec la position le long de la première direction (X) ;

ou dans lequel, à l'intérieur de la section de fuite, au moins une des autres parties de paroi des tubes diverge le long de la troisième direction en s'éloignant de l'axe nominal, de sorte que le passage d'écoulement s'élargit avec la position le long de la première direction, ou les deux.

12. Ensemble tube (112) selon la revendication 11, dans lequel des rangées de tubes adjacentes (132a, 132b, 132c) sont contiguës le long d'autres bords d'attaque (148, 149) des autres parties de paroi (142, 143) des tubes (130) situés au niveau des entrées (138) des passages d'écoulement (136), ou sont contiguës le long d'autres bords de fuite (152, 153) des autres parties de paroi situées au niveau des sorties (139) des passages d'écoulement, ou les deux ;

dans lequel les rangées de tubes adjacentes sont mutuellement espacées dans la troisième direction (Z) à travers les sections médianes (169) pour délimiter les deuxièmes canaux de fluide (124) ;

et dans lequel les rangées de tubes adjacentes (132) sont mutuellement fixées par l'intermédiaire d'autres lignes de soudure continues (160) le long des autres bords d'attaque (148, 149), ou par l'intermédiaire d'autres lignes de soudure continues (161) le long des autres bords de fuite (152, 153), ou les deux.

13. Ensemble tube (12) selon l'une quelconque des revendications 1 à 12, dans lequel la paroi de délimitation (34) de chaque tube (30) forme une paroi unitaire continue, ayant une épaisseur sensiblement uniforme (Dt) dans des directions perpendiculaires à la première direction (X),
éventuellement dans lequel chaque partie de paroi latérale (40, 41) a une forme en coupe transversale formant une courbe convexe, ou dans lequel la paroi de délimitation (34) de chaque tube (30) a une forme en coupe transversale formant une courbe convexe fermée.

14. Ensemble tube (12) selon l'une quelconque des revendications 1 à 13, dans lequel la paroi de délimitation (34) de chaque tube (30) a une forme en coupe transversale sensiblement quadrilatérale, de préférence une forme en coupe transversale sensiblement rectangulaire, dans des plans perpendiculaires à la première direction (X).

15. Ensemble tube (12) selon l'une quelconque des revendications 1 à 14, dans lequel chacun des tubes (30) est formé à partir d'un tube semi-fini qui est constituté essentiellement d'un métal ou d'un alliage métallique, dont une ou plusieurs surfaces sont revêtues d'une couche de verre avant d'agencer les tubes dans les rangées de tubes (32), ou dans lequel chacun des tubes (30) est constitué essentiellement d'un métal, d'un alliage métallique, d'une céramique ou d'un verre.

16. Dispositif échangeur de chaleur à tube (10), comprenant :

- un cadre (14), et

- un ensemble tube (212) selon l'une quelconque des revendications 1 à 15, monté sur un côté interne du cadre ;

éventuellement dans lequel un premier groupe (230a1) de tubes dans une rangée de tubes (232a) fournit un passage au premier fluide (226), et un second groupe (230a2) de tubes dans une rangée de tubes (232a) fournit un passage à un autre fluide (227) qui diffère du premier fluide.

Drawing