Heat transfer plate

Abstract

A heat transfer plate (2a) is provided having an upward transition region (16). The upward transition region (16) is provided with a transition pattern (50) comprising alternately arranged support transition peaks (60) and support transition valleys (62). At least one upper portion (60t) of each of the support transition peaks (60) extends in a first plane (P1), and at least one bottom portion (62b) of each of the support transition valleys (62) extends in a second plane (P2). An infinite virtual transition line (68) extends through two opposite endpoints (70, 72) of each of the support transition peaks (60) and support transition valleys (62). The heat transfer plate (2a) further comprises a front gasket groove (46) having a region front gasket groove portion (46a). The bottom (55) of the front gasket groove (46) extends between the first and second planes (P1, P2) along at least half the length of the front gasket groove portion (46a). The heat transfer plate is characterized in that a virtual transfer line (68) extends parallel to the longitudinal central axis (L) of the heat transfer plate (2a) with respect to at least a number of support transfer peaks (60) and support transfer valleys (62).

Description

Technical Field

[0001] The present invention relates to a heat transfer plate and its design.

Background Art

[0002] A plate heat exchanger (PHE) typically consists of two end plates between which several heat transfer plates are stacked or packed side by side. The heat transfer plates of a PHE can be of the same or different types and can be stacked in different ways. In some PHEs, the front and back sides of one heat transfer plate face the back and front sides of another heat transfer plate respectively, and every other heat transfer plate is stacked in a state where it is rotated upside down with respect to the remaining heat transfer plates. Typically, this is referred to as the heat transfer plates being "rotated" relative to each other. In other PHEs, the front and back sides of one heat transfer plate face the front and back sides of another heat transfer plate respectively, and every other heat transfer plate is stacked in a state where it is rotated upside down with respect to the remaining heat transfer plates. Typically, this is referred to as the heat transfer plates being "reversed" relative to each other.

[0003] In a certain well-known type of PHE, a so-called gasketed PHE, gaskets are placed between the heat transfer plates. The end plates, and by extension the heat transfer plates, are pressed against each other by a certain type of clamping means, whereby the gaskets seal between the heat transfer plates. One passage is provided between each pair of adjacent heat transfer plates, and counterflow passages are formed between the heat transfer plates. Two fluids, initially at different temperatures, that are sent through the inlet / outlet to enter and exit the PHE can flow alternately through every other passage in order to transfer heat from one fluid to the other, and the fluids enter and exit the passages through inlet port holes / outlet port holes in the heat transfer plates that communicate with the inlet / outlet of the PHE.

[0004] Typically, a heat transfer plate comprises two end portions and a central portion. The end portions include inlet port holes, outlet port holes, and distribution areas pressed with a corrugated distribution pattern of peaks and valleys. Similarly, the central portion includes a heat transfer area pressed with a corrugated heat transfer pattern of peaks and valleys. The peaks and valleys of the distribution pattern and heat transfer pattern of one heat transfer plate are arranged to contact the peaks and valleys of the distribution pattern and heat transfer pattern of other adjacent heat transfer plates in a plate heat exchanger in a contact area. Typically, the contact area provides mechanical strength to the plate pack.

[0005] The primary function of the distribution region of a heat transfer plate is to distribute the fluid across the width of the heat transfer plate before it reaches the heat transfer region, and to collect the fluid after it has passed through the heat transfer region and guide it out of the passage. On the other hand, the primary function of the heat transfer region is heat transfer. Because the distribution region and the heat transfer region have different primary functions, the distribution pattern is usually different from the heat transfer pattern. In the transition between the distribution region and the heat transfer region, that is, where the plate pattern changes, there may be relatively small contacts between adjacent heat transfer plates of the plate pack. As a result, the stiffness of the plate pack in the transition may be somewhat reduced when compared to the stiffness of the rest of the plate pack.

[0006] A solution to the above problem is presented in the applicant's patent EP1899671. This solution involves providing a narrow band between the heat transfer plate distribution region and the heat transfer region. The narrow band is provided with a herringbone pattern, more specifically, with closely spaced "steep angle" peaks and valleys that result in closely spaced point contact regions between the heat transfer plates when the heat transfer plates are lined up in the plate pack. This improves the rigidity of the plate pack at the transition between the heat transfer region and the distribution region.

[0007] The aforementioned narrow bandwidth can result in relatively large pressure losses within the passage, even if it solves the rigidity problem in the transition area. This can be disadvantageous, particularly if the heat transfer plate has a heat transfer region where a heat transfer pattern that results in relatively small pressure losses within the passage is provided, as it can reduce the efficiency of the heat transfer plate. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] European Patent No. 1899671 [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a heat transfer plate that at least partially solves the problems of the prior art described above. The basic concept of the present invention is to provide a narrow band in the transition between the heat transfer region and the distribution region of the heat transfer plate that promotes mechanical strength but is designed to have lower pressure loss compared to the prior art. A heat transfer plate, sometimes simply referred to herein as a “plate,” for achieving the above object is defined in the appended claims and is discussed below. [Means for solving the problem]

[0010] The heat transfer plate according to the present invention comprises an upper end portion, a central portion, and a lower end portion, which are continuously arranged along the longitudinal central axis of the heat transfer plate. The longitudinal central axis divides the heat transfer plate into a first half and a second half and extends perpendicular to the transverse central axis of the heat transfer plate. The central portion comprises a heat transfer region. The upper end portion comprises a first port hole, a second port hole, an upward distribution region, and an upward transition region. The upward transition region is adjacent to the upward distribution region along a first boundary line and adjacent to the heat transfer region along a second boundary line. The lower end portion comprises a third port hole, a fourth port hole, a downward distribution region, and a downward transition region. The downward transition region is adjacent to the downward distribution region along a third boundary line and adjacent to the heat transfer region along a fourth boundary line. A distribution pattern is provided in the upper distribution region. A transition pattern is provided in the upward transition region. A heat transfer pattern is provided in the heat transfer region. The transition pattern differs from the distribution pattern and the heat transfer pattern. The transition pattern comprises supporting transition peaks and supporting transition valleys that are alternately arranged when viewed from the front of the heat transfer plate. At least several, preferably at least most, upper portions of each supporting transition peak extend in a first plane, and at least several, preferably at least most, lower portions of each supporting transition valley extend in a second plane. Infinite virtual transition lines extend between the two opposite endpoints of each of the supporting transition peaks and supporting transition valleys. The heat transfer plate defines several separate virtual transition lines. The heat transfer plate further comprises a front gasket groove on the front side. Furthermore, the front gasket groove comprises a region front gasket groove portion that encloses a heat transfer region, upper and lower transition regions, upper and lower distribution regions, and two of the first, second, third, and fourth port holes. The bottom of the front gasket groove extends between the first and second planes along at least half the length of the front gasket groove portion of the region. The heat transfer plate is characterized in that there are at least several virtual migration lines, preferably with respect to at least most of the supporting migration peaks and supporting migration valleys, that extend parallel to the longitudinal central axis of the heat transfer plate.

[0011] In this specification, unless otherwise stated, the peaks and valleys of a heat transfer plate are the peaks and valleys when the front side of the heat transfer plate is viewed. Essentially, what is a peak when viewed from the front side of the plate is a valley when viewed from the opposite rear side of the plate, and what is a valley when viewed from the front side of the plate is a peak when viewed from the rear side of the plate, and vice versa.

[0012] The first, second, third, and fourth boundaries intersect the longitudinal central axis of the heat transfer plate. The first and / or second boundary, like the third and / or fourth boundary, may be straight and as parallel as possible to the transverse central axis, or it may be curved, for example, bulging inward when viewed from the center of the heat transfer plate.

[0013] The first plane and the second plane can be parallel.

[0014] In this specification, “most” means more than half.

[0015] The virtual transfer line may be positioned equidistant across part or all of the heat transfer plate. Furthermore, the two port holes surrounded by the front gasket groove region may be positioned on the same side of the longitudinal central axis of the heat transfer plate. Both of these configurations can enable plate packing of the heat transfer plate according to the present invention, which may be either "reversed" or "rotated" relative to each other.

[0016] The heat transfer plate may further comprise an outer edge portion extending along the outer edge or periphery of the plate, the outer edge portion comprising a corrugation extending between the first plane and the second plane. The entire outer edge portion, or only one or more portions thereof, may comprise the corrugation. The corrugation can be distributed evenly or unevenly along the edge portion, and may appear uniform or not. The corrugation defines peaks and valleys that can give the edge portion a wavy design. When the heat transfer plate is placed in a plate heat exchanger, the corrugation can be positioned on the front side of the heat transfer plate to abut against a first adjacent heat transfer plate, and on the opposite rear side of the heat transfer plate to abut against a second adjacent heat transfer plate.

[0017] The heat transfer plates are arranged to be combined with other heat transfer plates in the plate pack. All heat transfer plates in the plate pack may be of the same type. Alternatively, the heat transfer plates in the plate pack may be of different types, but preferably all are configured according to claim 1.

[0018] If the virtual migration line extends parallel to the longitudinal central axis of the heat transfer plate at points where it passes through at least several support migration peaks and troughs, the upward distribution region can provide a relatively small but relatively large contact area between the heat transfer plate and adjacent heat transfer plates in the plate pack. Furthermore, this can provide good mechanical strength and relatively small pressure loss in the upward distribution region.

[0019] The heat transfer plate may be configured such that the bottom of the front gasket groove is parallel to the first and second planes and extends along a central plane, a so-called half-plane, that extends in the halfway between the first and second planes, for at least half the length of the front gasket groove region. Such a configuration can enable plate packing of the heat transfer plate according to the present invention, which is either "reversed" or "rotated" relative to each other.

[0020] The support transition ridges may have the same or different, any suitable shape and / or size. Similarly, the support transition valleys may have the same or different, any suitable shape and / or size. As an example, at least several, preferably at least most, support transition ridges and valleys may be elongated, i.e., have a length greater than their width, which is beneficial with respect to flow resistance and pressure loss across the heat transfer plate. Additional / alternatively, at least several, preferably at least most, support transition ridges and valleys may be straight, i.e., have a longitudinal central axis, which can make the heat transfer plate suitable for use in plate packs of heat transfer plates that are "inverted" as well as "rotated".

[0021] Furthermore, the heat transfer plate can be configured such that the virtual transfer lines are at least multiple, preferably, for at least a majority of each of the supporting transfer peaks and valleys, they coincide with the respective longitudinal central axis of the supporting transfer peak or valley. Such a configuration allows for supporting transfer peaks and valleys having two symmetrical axes parallel to the longitudinal and transverse central axes of the heat transfer plate. Moreover, such a configuration makes the heat transfer plate suitable for use in plate packs of heat transfer plates that are "inverted" as well as "rotated".

[0022] The total number of support migration peaks and support migration valleys may exceed the number of virtual migration lines defined by the heat transfer plate, such that one identical virtual migration line extends through two or more of the support migration peaks and support migration valleys. However, according to one embodiment of the present invention, at least a number, preferably at least most, of the virtual migration lines defined by the heat transfer plate extend through only one of the support migration peaks and support migration valleys. Such a design allows for a heat transfer plate in which the upper distribution region has only one row of alternately arranged support migration peaks and support migration valleys.

[0023] There can be at least a plurality of heat transfer plates, and preferably, the central points of at least most of the support transition ridges and support transition valleys can be arranged along a virtual center line that intersects the longitudinal central axis of the heat transfer plate. The virtual center line can be straight and as parallel as possible to the transverse central axis of the heat transfer plate. Alternatively, the virtual center line can be curved.

[0024] The heat transfer plate can define an even number x of virtual transition straight lines. This can result in an odd number x - 1 of gaps between the virtual transition straight lines. Further, particularly when the virtual straight lines are evenly distributed across the heat transfer plate, the longitudinal central axis may divide, at half, the central gap in the length direction of the gaps, and (x - 2) / 2 complete gaps, that is, the gaps not divided by the longitudinal central axis, may be arranged in each of the first half and the second half of the heat transfer plate. Such a design can be made suitable for use in a plate pack including plates "rotated" relative to each other and a plate pack including plates "reversed" relative to each other.

[0025] Excluding the support transition ridges and support transition valleys, the transition pattern may further include turbulent transition ridges and turbulent transition valleys. The upper portions of at least a plurality, and preferably at least most, of the turbulent transition ridges can extend in a third plane that is parallel to the first plane and the second plane between the first plane and the second plane. The bottom portions of at least a plurality, and preferably at least most, of the turbulent transition valleys can extend in a fourth plane that is parallel to the second plane and the third plane between the second plane and the third plane. At least a plurality, and preferably at least most, of the turbulent transition ridges and turbulent transition valleys can be arranged alternately in the gaps between the virtual transition straight lines, and for adjacent ones of the virtual transition straight lines, the support transition ridges and the support transition valleys can be connected.

[0026] The third plane and the fourth plane may or may not be arranged at the same distance from the central plane.

[0027] The turbulent transition ridges and the turbulent transition valleys can have an advantageous effect of increasing the turbulence brought about by the heat transfer plate, thereby increasing the heat transfer capacity of the heat transfer plate. The ridges and valleys of the transitional turbulent flow can be arranged higher / deeper and more closely, and the heat transfer capacity can be improved more.

[0028] At least a plurality, preferably at least most of the turbulent transition ridges and the turbulent transition valleys can extend inclined with respect to the transverse central axis of the heat transfer plate along at least the central portion of their longitudinal extension.

[0029] When the heat transfer plate has inclined turbulent transition ridges and turbulent transition valleys, it can be avoided that the turbulent transition ridges and turbulent transition valleys of the heat transfer plate are aligned with the turbulent ridges and turbulent valleys of other similar heat transfer plates that are "rotated" or "reversed" and in contact with the first heat transfer plate in the plate pack. This can result in a passage having a depth that varies along the longitudinal central axis of the heat transfer plate between the heat transfer plates by the aligned turbulent transition ridges and turbulent transition valleys, which can further result in an intermittent restriction of the flow through the passage.

[0030] At least a number of turbulent transition peaks and valleys, preferably at least the majority, that are fully positioned within the first half of the heat transfer plate, i.e., positioned with a full gap, can extend along their central portions at a minimum angle α such that 0 < α < 90, clockwise with respect to the transverse central axis of the heat transfer plate. At least a number of remaining turbulent transition peaks and valleys, preferably at least the majority, can extend along their central portions at a minimum angle β such that 0 < β < 90, counterclockwise with respect to the transverse central axis of the heat transfer plate. Thus, the opposing turbulent transition peaks and valleys of two adjacent heat transfer plates configured in this way in a plate pack extend parallel to each other when the plates are "reversed" as well as "rotated" relative to each other. Such parallel extensions can result in unnecessary restriction of flow between the plates.

[0031] α can be different from β. Alternatively, α may be equal to β. In the case of the equal choice, the opposing turbulent transition peaks and troughs of two adjacent heat transfer plates thus configured in a plate pack can result in them extending equally with respect to each other, regardless of whether the plates are "rotated" or "inverted" relative to each other.

[0032] The heat transfer plate may be configured such that the upward and downward transfer regions are symmetrical with respect to the transverse central axis of the heat transfer plate to at least 50 percent. Such a design can make the heat transfer plate suitable for use in plate packs with plates that are "rotated" relative to each other, and plate packs with plates that are "inverted" relative to each other.

[0033] The heat transfer (HT) pattern of a heat transfer plate may comprise supporting HT peaks and supporting HT valleys. At least a number, preferably most, of the supporting HT peaks and valleys can extend longitudinally parallel to the longitudinal central axis of the heat transfer plate. At least a number, preferably most, of the upper portions of each supporting HT peak can extend in a first plane, and at least a number, preferably most, of the bottom portions of each supporting HT valley can extend in a second plane. At least a number, preferably most, of the supporting HT peaks and valleys can be alternately arranged along several separate virtual longitudinal HT lines extending parallel to the longitudinal central axis of the heat transfer plate, and along several separate virtual transverse HT lines extending parallel to the transverse central axis of the heat transfer plate. At least a number, preferably most, of the supporting HT peaks and valleys can be centered on the virtual longitudinal HT lines and can extend between adjacent virtual transverse HT lines. The heat transfer pattern may further comprise turbulent HT peaks and turbulent HT valleys. At least several, preferably the upper portions of most turbulent HT peaks, may extend in a fifth plane positioned parallel to the first and second planes between the first and second planes. At least several, preferably the bottom portions of most turbulent HT valleys, may extend in a sixth plane positioned parallel to the second and fifth planes between the second and fifth planes. At least several, preferably at least most turbulent HT peaks and valleys may be arranged alternately in the gaps between virtual longitudinal HT lines, connecting supporting HT peaks and supporting HT valleys along adjacent virtual longitudinal HT lines. Such an HT pattern can allow for relatively little contact between adjacent heat transfer plates in a plate pack, which can be advantageous in some applications, for example, when hygiene is particularly important.

[0034] Turbulent heat transfer plates (HTs) can increase the turbulence induced by the heat transfer plates, thereby increasing the heat transfer capacity of the heat transfer plates. The higher / deeper and more densely packed the turbulent HTs are positioned, the greater the heat transfer capacity can be.

[0035] The fifth and sixth planes may or may not be located at the same distance from the central plane. The fifth plane may or may not coincide with the third plane referenced above. Similarly, the sixth plane may or may not coincide with the fourth plane referenced above.

[0036] The number of virtual longitudinal heat transfer lines (HTs) can be even or odd. These virtual longitudinal HTs can be equidistant across part or all of the heat transfer region.

[0037] The number of virtual transverse heat transfer lines (HTs) can be even or odd. These virtual transverse heat transfer lines can be equidistant across part or all of the heat transfer region.

[0038] At least several, preferably at least most, virtual longitudinal HT lines can coincide with one of each of the virtual transition lines. This allows the supporting transition peaks and valleys to align with the supporting HT peaks and valleys. This can be beneficial with respect to flow resistance across the heat transfer plate.

[0039] The HT pattern of the heat transfer plate is at least one or more along at least the central portion of its longitudinal extension, and preferably at least most of the turbulent HT peaks and turbulent HT valleys may be further made to extend at an inclination with respect to a virtual transverse HT straight line.

[0040] Where turbulent HT crests and turbulent HT valleys extend diagonally between virtual longitudinal HT lines along at least a portion of their length, they can connect supporting HT crests and valleys that are not located between the same two virtual transverse HT lines. The “rotation” and “reversal” of two heat transfer plates having non-diagonal turbulent crests and turbulent HT valleys relative to each other can result in a passage where a turbulent HT crest or turbulent HT valley of one plate is eventually directly aligned with a turbulent HT crest or turbulent HT valley of the other plate. Such a passage can have a depth that varies along the longitudinal central axis of the heat transfer plates, which can consequently result in intermittent restriction of flow through the passage. If the two heat transfer plates instead have oblique turbulent HT crests and turbulent HT troughs, the directly aligned turbulent HT crests and troughs, and consequently the changing depth of the passage, can be avoided when the plates are "reversed" and "rotated" relative to each other.

[0041] The heat transfer plates may consist of at least a number of plates, preferably designed such that the longitudinal extension of at least most of the support transition peaks and support transition valleys is smaller than the longitudinal extension of the support HT peaks and support HT valleys. This may be beneficial with respect to the mechanical strength of the plate pack comprising the heat transfer plates.

[0042] It should be emphasized that most, if not all, of the advantages of the heat transfer plate described above for the present invention become apparent when combined with other well-constructed heat transfer plates in a plate pack.

[0043] Further purposes, features, embodiments, and advantages of the present invention will become apparent not only from the following detailed description but also from the drawings.

[0044] The present invention will now be described in more detail with reference to the accompanying schematic drawings. [Brief explanation of the drawing]

[0045] [Figure 1a] This is a schematic plan view of the heat transfer plate. [Figure 1b] This is a schematic cross-sectional view along line AA in Figure 1a. [Figure 2a] This is a schematic plan view of the heat transfer plate in Figure 1a, which works in conjunction with the gasket. [Figure 2b] This is a schematic cross-sectional view along line BB in Figure 2a. [Figure 3] This is a schematic diagram of the outer edges of adjacent heat transfer plates in a plate pack, as viewed from the outside of the plate pack. [Figure 4] This is a magnified view of a portion of the heat transfer plate in Figure 1a. [Figure 5a] Figure 1a is a schematic diagram of the cross-section of the support transition peak of the heat transfer plate. [Figure 5b] Figure 1a is a schematic diagram of the cross-section of the support transition valley of the heat transfer plate. [Figure 6] Figure 1a shows schematic cross-sections of the turbulent transition peaks and valleys of the heat transfer plate, and the turbulent HT peaks and valleys. [Figure 7] This is a magnified view of a portion of the heat transfer plate in Figure 1a. [Figure 8] This is a magnified view of a portion of the heat transfer plate in Figure 1a. [Figure 9] Figure 1a is a schematic diagram of the cross-section of the heat transfer plate's support HT peaks and support HT valleys. [Figure 10] This is a magnified view of a portion of the heat transfer plate in Figure 1a. [Modes for carrying out the invention]

[0046] Figures 1a and 2a show heat transfer plates 2a of a gasketed plate heat exchanger as described in the introduction. A gasketed PHE, although not fully shown, consists of packs of heat transfer plates 2, such as heat transfer plate 2a, separated by a gasket 1, and similarly comprising one pack of heat transfer plates similar to that shown in Figure 2a. Referring to Figure 3, in the plate pack, the front side 4 of plate 2a (shown in Figures 1a and 2a) faces the adjacent plate 2b, and the rear side 6 of plate 2a (not visible in Figures 1a and 2a, but indicated in Figure 3) faces another adjacent plate 2c.

[0047] Referring to Figure 1a, the heat transfer plate 2a is a basically rectangular sheet of stainless steel. The heat transfer plate 2a comprises an upper end portion 8 having a first port hole 10, a second port hole 12, an upper distribution region 14, and an upper transition region 16. The upper transition region 16 is adjacent to the upper distribution region 14 along a first boundary line bl1 (shown as a dashed line) which is parallel to the transverse central axis T of the heat transfer plate 2a. The plate 2a further comprises a lower end portion 18 having a third port hole 20, a fourth port hole 22, a lower distribution region 24, and a lower transition region 26. The lower transition region 26 is adjacent to the lower distribution region 24 along a third boundary line bl3 (shown as a dashed line) which is parallel to the transverse central axis T of the heat transfer plate 2a. The plate 2a further comprises a central portion 28 having a heat transfer region 30, and an outer edge portion 32 extending around an upper distribution region 14, a lower distribution region 24, an upper transition region 16, a lower transition region 26, the heat transfer region 30, and port holes 10, 12, 20, and 22. The heat transfer region 30 is adjacent to the upper transition region 16 along a second boundary line bl2 (shown as a dashed line) and adjacent to the lower transition region 26 along a fourth boundary line bl4 (shown as a dashed line), with the second boundary line bl2 and the fourth boundary line bl4 being parallel to the transverse central axis T.

[0048] As is evident from Figure 1a, the upper portion 8, the central portion 28, and the lower portion 18 are continuously arranged along the longitudinal central axis L of plate 2a, and the longitudinal central axis L extends parallel to the first longitudinal side 34 and the second longitudinal side 36 in the half between the opposite first longitudinal side 34 and the second longitudinal side 36 of plate 2a. The longitudinal central axis L divides plate 2a into a first half 38 and a second half 40. Furthermore, the longitudinal central axis L extends perpendicular to the transverse central axis T of plate 2a, and the transverse central axis T extends parallel to the first short side 42 and the second short side 44 in the half between the opposite first short side 42 and the second short side 44 of plate 2a. Furthermore, the heat transfer plate 2a has a front gasket groove 46 on its front side 4 and a rear gasket groove 47 (indicated in Figures 1b and 2b) on its rear side 6. The front and rear gasket grooves are surrounded by an outer edge portion 32, partially aligned with each other, and arranged to receive their respective gaskets 1, as illustrated for the front gasket groove 46 in Figure 2a. The front gasket groove 46 comprises a region front gasket groove portion 46a that surrounds the heat transfer region 30, the upper distribution region 14, the lower distribution region 24, the upper transition region 16, the lower transition region 26, the first port hole 10, and the third port hole 20. The front gasket groove 46 further comprises two annular front gasket groove portions 46b, each surrounding one of the second port hole 12 and one of the fourth port hole 22. The region front gasket groove portion 46a and the annular front gasket groove portion 46b are formed integrally. Referring also to Figure 2a, the regional gasket groove portion 46a is positioned to receive the regional gasket portion 1a of gasket 1 (as also shown in Figure 2b), while each of the annular front gasket groove portions 46b is positioned to receive the annular gasket portion 1b of gasket 1.

[0049] The heat transfer plate 2a is pressed in a conventional manner with a pressurizing tool so as to give the desired structure, more specifically, the front and rear gasket grooves and different corrugation patterns in different parts of the heat transfer plate. As discussed in the introduction, the corrugation patterns are optimized for the specific function of each plate part. Thus, the upper distribution region 14 and the lower distribution region 24 are provided with a distribution pattern 48, the upper transition region 16 and the lower transition region 26 are provided with a transition pattern 50, and the heat transfer region 30 is provided with a heat transfer pattern 52. The distribution pattern 48, the transition pattern 50, and the heat transfer pattern 52 are all different from each other. Furthermore, the outer edge portion 32 is provided with a corrugation 54 that makes the outer edge portion 32 more rigid, thereby making the heat transfer plate 2a more resistant to deformation. Furthermore, the corrugation 54 forms a support structure that is positioned to abut against the corrugation of adjacent heat transfer plates in the plate pack of the PHE. Referring again to Figure 3, which shows the periphery contact between the heat transfer plate 2a of the plate pack and the two adjacent heat transfer plates 2b and 2c along the main longitudinal parts 34, 36 (Figure 1a), the corrugation 54 extends in the first plane P1 and the second plane P2, which are parallel to the plane of the diagram in Figure 1a. The central plane CP extends in the half between the first plane P1 and the second plane P2. As is clear from Figure 1b, the bottom 55 of the front gasket groove 46 and the bottom 57 of the rear gasket groove 47 extend in this central plane CP, that is, in the so-called half-plane.

[0050] Referring to Figure 1a, the distribution pattern 48 is of the so-called chocolate type, comprising elongated distribution peaks 56 and distribution valleys 58 arranged to form their respective grids within the upper distribution region 14 and the lower distribution region 24, respectively. The upper portion of each distribution peak 56 extends in the first plane P1, and the bottom portion of each distribution valley 58 extends in the second plane P2. The distribution peaks 56 and distribution valleys 58 are positioned to abut the distribution peaks and distribution valleys of adjacent heat transfer plates in the plate pack of the PHE. The chocolate type of distribution pattern is well known and will not be described in further detail herein.

[0051] Referring to Figure 4, which includes an enlargement of the upward transition region 16, the transition pattern 50 comprises elongated, straight support transition peaks 60 and support transition valleys 62 that extend longitudinally parallel to the longitudinal central axis L of plate 2a (Figure 1a). Referring to Figure 5a, which shows the central cross-section of the support transition peaks 60 and support transition valleys 62, cut parallel to their longitudinal extensions, i.e., cut parallel to the longitudinal central axis L of plate 2a, and Figure 5b, which shows the central cross-section of the support transition valleys 62, the upper portions 60t of each support transition peak 60 extend in a first plane P1, while the bottom portions 62b of each support transition valley 62 extend in a second plane P2.

[0052] Referring to Figures 1a and 4, within the upward transition region 16, there are five support transition peaks 60 and five support transition valleys 62. These are arranged alternately in rows parallel to the transverse central axis T of the heat transfer plate 2a, with the center point c of each of them located on a virtual central line cl perpendicular to the longitudinal central axis L of the heat transfer plate 2a. An infinite virtual transition line 68, parallel to the longitudinal central axis L of the heat transfer plate 2a, extends through two opposite endpoints 70 and 72 of the support transition peaks 60 and support transition valleys 62, and coincides with one of the longitudinal central axes lt of each of the support transition peaks 60 and support transition valleys 62. This means that the heat transfer plate 2a defines x = 10 infinite virtual transition lines 68.

[0053] Referring to Figures 4 and 7, the transition pattern 50 further comprises elongated turbulent transition peaks 74 and elongated turbulent transition valleys 76. Some of the turbulent transition peaks 74 and valleys 76 are alternately arranged in the gaps 78 (78a, 78b) between adjacent virtual transition lines 68, and some of these turbulent transition peaks 74 and valleys 76 are positioned to connect supporting transition peaks 60 and supporting transition valleys 62 along adjacent virtual transition lines 68. The remaining turbulent transition peaks 74 and valleys 76 are alternately arranged outside the outermost virtual transition lines 68 that extend from the outermost supporting transition peaks 60 and supporting transition valleys 62.

[0054] Since the number x of the virtual transition lines 68 is 10, there are 9 gaps 78. The longitudinal central axis L of plate 2a (Figure 1a) divides the central gap 78a in half lengthwise, leaving four complete gaps 78b on each side of the longitudinal central axis L of plate 2a. The virtual transition line 68 that defines the central gap 78a forms the central virtual longitudinal transition lines 68a and 68b.

[0055] As is evident from the figure, the turbulent transition peaks 74 and turbulent transition valleys 76, or more specifically, their respective central portions 74a and 76a (Figure 7), extend obliquely to the transverse central axis T of the heat transfer plate 2a (Figure 1a). In the central virtual longitudinal transition line 68a, the transition pattern 50 changes. More specifically, referring to Figures 4 and 7, to the left of line 68a (as seen in Figure 4), the central portions 74a and 76a of the turbulent transition peaks 74 and turbulent transition valleys 76 (Figure 7) extend clockwise at a minimum angle α (maximum angle = α + 180) degrees with respect to the transverse central axis T of the heat transfer plate 2a (Figure 1a). Furthermore, the central portions 74a and 76a of the turbulent transition peak 74 and turbulent transition valley 76 extend counterclockwise with respect to the transverse central axis T at a minimum angle β (maximum angle = β + 180) degrees, respectively, to the right of line 68a (as seen in Figure 4). Here, α = β = 25, but this may not be the case in alternative embodiments where α can be different from β, and α and β may have other values ​​in the range of 15 to 75.

[0056] Furthermore, referring to Figure 6, which shows the central cross-sections of the turbulent transition peaks 74 and turbulent transition valleys 76 cut perpendicular to their longitudinal extension, the upper portions 74t of each turbulent transition peak 74 extend in the third plane P3, while the bottom portions 76b of each turbulent transition valley 76 extend in the fourth plane P4.

[0057] The third plane P3 is parallel to the first plane P1 and the central plane CP, and is located between the first plane P1 and the central plane CP, while the fourth plane P4 is parallel to the central plane CP and is located just below the central plane CP, i.e., between the second plane P2 and the central plane CP. The turbulent transition peaks 74 and turbulent transition valleys 76 are positioned and designed within the upward transition region 16 so that the first volume V1 surrounded by plate 2a and the first plane P1 is smaller than the second volume V2 surrounded by plate 2a and the second plane P2.

[0058] The upper end portion 8 and the lower end portion 18 of the heat transfer plate 2a, and consequently the upward transition region 16 and the downward transition region 26, are symmetrical with respect to the transverse central axis T of the heat transfer plate 2a.

[0059] Referring to Figures 1a and 8, which include an enlargement of a portion of the heat transfer region 30, the heat transfer (HT) pattern 52 comprises straight, elongated support HT peaks 80 and support HT valleys 82 that extend longitudinally parallel to the longitudinal central axis L of the plate 2a (Figure 1a). Referring to Figure 9, which shows the central cross-section of the support HT peaks 80 and support HT valleys 82 cut parallel to their longitudinal extension, i.e., cut parallel to the longitudinal central axis L of the plate 2a, the upper portion 80t of each support HT peak 80 extends in a first plane P1, while the bottom portion 82b of each support HT valley 82 extends in a second plane P2. For example, as is clear from Figures 4 and 7, the longitudinal extension of the support HT peaks 80 and support HT valleys 82 is greater than the longitudinal extension of the support transition peaks 60 and support transition valleys 62.

[0060] Referring to Figures 1a and 8, the supporting HT peaks 80 and supporting HT valleys 82 are alternately arranged along a virtual longitudinal HT line 84 that is equidistant at y=10 and extends parallel to the longitudinal central axis L of plate 2a. The virtual longitudinal HT line 84 extends through the centers of each of the supporting HT peaks 80 and supporting HT valleys 82 and coincides with one of each of the virtual transition lines 68. Furthermore, the supporting HT peaks 80 and supporting HT valleys 82 are alternately arranged along several equidistant virtual transverse HT lines 86 that extend parallel to the transverse central axis T of plate 2a. Only half of these virtual transverse HT lines 86 are shown in Figure 1a. The supporting HT peaks 80 and supporting HT valleys 82 are arranged between the virtual transverse HT lines 86. The two outermost of the virtual transverse HT lines 86 coincide with one of each of the second boundary line bl2 and the fourth boundary line bl4.

[0061] Referring to Figures 1a and 8, the heat transfer pattern 52 further comprises elongated turbulent HT peaks 88 and elongated turbulent HT valleys 90. Some of the turbulent HT peaks 88 and turbulent HT valleys 90 are alternately arranged in the gaps 92 (92a, 92b) between adjacent virtual longitudinal HT lines 84, and some of these turbulent HT peaks 88 and turbulent HT valleys 90 are positioned to connect supporting HT peaks 80 and supporting HT valleys 82 along adjacent virtual longitudinal HT lines 84. The remainder of the turbulent HT peaks 88 and turbulent HT valleys 90 are alternately arranged outside the outermost virtual longitudinal HT lines 84 extending from the outermost supporting HT peaks 80 and supporting HT valleys 82.

[0062] Since the number y of the virtual longitudinal HT line 84 is 10, there are 9 gaps 92. The longitudinal central axis L of plate 2a (Figure 1a) divides the central gap 92a in half lengthwise, leaving 4 complete gaps 92b on each side of the longitudinal central axis L of plate 2a. The virtual longitudinal HT line 84 that defines the central gap 92a forms the central virtual longitudinal HT lines 84a and 84b.

[0063] In particular, as is evident from Figure 10, the turbulent HT peaks 88 and turbulent HT valleys 90, or more specifically, their respective central portions 88a and 90a, extend obliquely to the transverse central axis T of the heat transfer plate 2a (Figure 1a). In the central virtual longitudinal HT line 84a, the heat transfer pattern 52 changes. More specifically, referring to Figures 1a and 10, the central portions 88a and 90a of the turbulent HT peaks 88 and turbulent HT valleys 90 extend clockwise at a minimum angle α (maximum angle = α + 180) degrees with respect to the transverse central axis T of the heat transfer plate 2a (Figure 1a) toward the left side of line 84a (as seen in the figures). Furthermore, the central portions 88a and 90a of the turbulent HT crest 88 and turbulent HT valley 90 extend counterclockwise with respect to the transverse central axis T at a minimum angle β (maximum angle = β + 180) degrees, respectively, toward the right side of line 84a (as seen in the figure). Here, α = β = 25, but this may not be the case in alternative embodiments where α can be different from β, and α and β may have other values ​​in the range of 15 to 75.

[0064] Furthermore, referring to Figure 6, which shows the central partial cross-sections of the turbulent HT crests 88 and turbulent HT valleys 90 cut perpendicular to their longitudinal extension, the upper portions 88t of each turbulent HT crest 88 extend in the fifth plane P5, while the bottom portions 90b of each turbulent HT valley 90 extend in the sixth plane P6. The fifth plane P5 coincides with the third plane P3, and the sixth plane P6 coincides with the fourth plane P4. Since the turbulent HT crests 88 and turbulent HT valleys 90 are positioned and designed within the heat transfer region 30, the first volume V1 enclosed by the plate 2a and the first plane P1 is smaller than the second volume V2 enclosed by the plate 2a and the second plane P2.

[0065] Therefore, the heat transfer plate 2a includes turbulent transfer peaks 74 and turbulent transfer valleys 76 that connect supporting transfer peaks 60 and supporting transfer valleys 62 along adjacent virtual transfer lines 68. Furthermore, the heat transfer plate 2a includes turbulent HT peaks 88 and turbulent HT valleys 90 that connect supporting HT peaks 80 and supporting HT valleys 82 along adjacent virtual longitudinal HT lines 84. In particular, as is evident from the figures 4 and 7, some of the turbulent transfer peaks 74 and turbulent transfer valleys 76 connect one of the supporting transfer peaks 60 and supporting transfer valleys 62 to one of the supporting HT peaks 80 and supporting HT valleys 82. Similarly, some of the turbulent HT peaks 88 and turbulent HT valleys 90 connect one of the supporting HT peaks 80 and supporting HT valleys 82 to one of the supporting transfer peaks 60 and supporting transfer valleys 62.

[0066] As previously stated and as shown in Figure 3, in the plate pack, plate 2a is positioned between plates 2b and 2c. In the heat transfer pattern design specified earlier, plates 2b and 2c may be positioned either "inverted" or "rotated" relative to plate 2a.

[0067] When plates 2b and 2c are arranged “inverted” with respect to plate 2a, the front side 4 and the rear side 6 of plate 2a face the front side 4 of plate 2b and the rear side 6 of plate 2c, respectively. This means that the support transition crest 60 and the support HT crest 80 of plate 2a abut against the support transition crest and the support HT crest of plate 2b, and the support transition trough 62 and the support HT trough 82 of plate 2a abut against the support transition trough and the support HT trough of plate 2c. Further, the turbulent flow transition crest 74 and the turbulent flow HT crest 88 of plate 2a face the turbulent flow transition crest and the turbulent flow HT crest of plate 2b but do not abut, and extend at an angle 2α = 2β with respect to those crests, and the turbulent flow transition trough 76 and the turbulent flow HT trough 90 of plate 2a face the turbulent flow transition trough and the turbulent flow HT trough of plate 2c but do not abut, and extend at an angle 2α = 2β with respect to those troughs. Among the heat transfer region 30, the upper transition region 16, and the lower transition region 26, plates 2a and 2b form a passage with a volume of 2×V1, and plates 2a and 2c form a passage with a volume of 2×V2, that is, since V1 < V2, two asymmetric passages are formed.

[0068] When plates 2b and 2c are positioned "rotated" relative to plate 2a, the front 4 and rear 6 of plate 2a face the rear 6 of plate 2b and the front 4 of plate 2c, respectively. This means that the support transition peaks 60 and support HT peaks 80 of plate 2a abut the support transition valleys and support HT valleys of plate 2b, and the support transition valleys 62 and support HT valleys 82 of plate 2a abut the support transition peaks and support HT peaks of plate 2c. Furthermore, the turbulent transition peaks 74 and turbulent HT peaks 88 of plate 2a face the turbulent transition valleys and turbulent HT valleys of plate 2b but do not abut them, and the turbulent transition valleys 76 and turbulent HT valleys 90 of plate 2a face the turbulent transition peaks and turbulent HT peaks of plate 2c but do not abut them. In all gaps 78 and 92 except for the central gaps 78a and 92a, the turbulent transition peaks 74, turbulent transition valleys 76, turbulent HT peaks 88, and turbulent HT valleys 90 of plate 2a extend at an angle of 2α=2β with respect to the turbulent transition valleys and turbulent HT valleys of plate 2b and the turbulent transition peaks and turbulent HT peaks of plate 2c, respectively. In the central gaps 78a and 92a, the turbulent transition peaks 74, turbulent transition valleys 76, turbulent HT peaks 88, and turbulent HT valleys 90 of plate 2a extend parallel to the turbulent transition valleys and turbulent HT valleys of plate 2b and the turbulent transition peaks and turbulent HT peaks of plate 2c, respectively. Within the heat transfer region 30, the upward transfer region 16, and the downward transfer region 26, plates 2a and 2b form a passage of volume V1 + V2, and plates 2a and 2c form a passage of volume V1 + V2, that is, two symmetrical passages are formed.

[0069] The embodiments described earlier in this invention should be viewed merely as examples. Those skilled in the art will understand that the embodiments under consideration can be modified in several ways without departing from the concept of the invention.

[0070] For example, the number of virtual transition lines x does not have to be 10, like the number of virtual longitudinal HT lines y; it can be more or less. Plates designed in this way can be "inverted" relative to each other but cannot be "rotated". Furthermore, in alternative embodiments, x may be different from y.

[0071] Furthermore, the transition pattern and heat transfer pattern do not need to change along the central virtual transition line and the central virtual longitudinal HT line, respectively, as described above. For example, turbulent peaks and turbulent valleys can instead have the same orientation within the complete transition and heat transfer patterns. Plates with such patterns can be "reversed" relative to each other, but they cannot be "rotated".

[0072] The turbulent transition peaks, turbulent hard peaks, turbulent transition valleys, and / or turbulent hard peak valleys do not need to be designed as shown in the drawings and may have any suitable design, or may be omitted or not exist at all.

[0073] Support transition peaks, support HT peaks, support transition valleys, and / or support HT valleys do not need to be elongated parallel to the longitudinal central axis of the plate and can have any suitable design. For example, they can be secondary or elongated parallel to the transverse central axis of the plate.

[0074] α and β do not need to be the same in the transfer pattern and heat transfer pattern.

[0075] Essentially, the distribution pattern doesn't have to be of the same kind as chocolate; it could be of any other kind.

[0076] The heat transfer plate does not need to be asymmetrical; it may be symmetrical. Therefore, referring to Figures 6 and 9, the plate may be designed such that V1 = V2.

[0077] The bottom of the front gasket groove does not need to extend in a half-plane. Furthermore, the bottom of the front gasket groove does not need to extend in the same plane along its full extension.

[0078] The plate pack described above contains only one type of plate. Instead, a plate pack may contain two or more different types of plates, such as plates with differently configured heat transfer and / or distribution patterns.

[0079] The heat transfer plate does not have to be rectangular and may have other shapes, such as essentially rectangular, circular, or elliptical, with rounded corners instead of right angles. The heat transfer plate does not have to be made of stainless steel and may be made of other materials such as titanium or aluminum.

[0080] It should be emphasized that attributes such as front, back, top, bottom, first, second, and third are used herein solely for the purpose of distinguishing between sub-items and are not used herein to represent any kind of orientation or relative order among sub-items.

[0081] Furthermore, it should be emphasized that details unrelated to the present invention are omitted, and that the figures are only schematic and not drawn to a consistent scale. It should also be noted that some of the figures are simpler than others. Therefore, some components may be shown in one figure but excluded in others. [Explanation of symbols]

[0082] 1 Gasket 1a Area gasket portion 1b Annular gasket portion 2, 2a, 2b, 2c Heat transfer plates 4 Front 6 Rear side 8 End part 10 First port hole 12 Second port hole 14 Upper distribution area 16 Upward transition region 18 Lower end part 20 Third port hole 22 Fourth port hole 24 Downward distribution area 26 Downward transition area 28 Central part 30 Heat transfer region 32 Outer edge part 34 First Longitudinal Side 36 Second Long Side 38. The first half 40. The second half 42 First short side 44 Second short side 46 Front gasket groove 46a Front gasket groove area 46b Annular front gasket groove portion 47 Rear gasket groove 48 distribution patterns 50 Transition Patterns 52 Heat transfer patterns 54 Waveform 55 bottom 56 Distribution Mountain 57 bottom 58 Distribution Valley 60 Support Transition Yamabe 60t upper part 62 Support Transition Valley 62b bottom part 68, 68a, 68b Virtual transition lines 70 end points 72 Endpoint 74 Turbulent transition mountain area 74a central part 74t upper part 76 Turbulent transition valley 76a central part 76b bottom part 78, 78a, 78b gap 80 Support HT Yamabe 80t upper part 82 Support HT Tanibe 82b bottom part 84, 84a, 84b Virtual longitudinal HT line 86 Virtual transverse HT straight line 88 Turbulence HT Yamabe 88a central part 88t upper part 90 Turbulent HT Valley 90a central part 90b bottom part 92, 92a, 92b gap bl1 The first boundary line bl2 The second boundary bl3 The Third Boundary bl4 The Fourth Boundary c center point cl center line CP center plane lt Longitudinal central axis L Longitudinal central axis P1 First Plane P2 Second Plane P3 Third Plane P4 The fourth plane P5 Fifth Plane P6 The sixth plane T Transverse central axis V1 First volume V2 Second volume x Number of virtual migration lines y: Number of virtual longitudinal HT lines α angle β angle

Claims

1. A heat transfer plate (2a), The heat transfer plate (2a) is divided into first and second halves (38, 40), and comprises an upper end portion (8), a central portion (28), and a lower end portion (18) which are continuously arranged along the longitudinal central axis (L) of the heat transfer plate (2a) that extends perpendicular to the transverse central axis (T) of the heat transfer plate (2a), the central portion (28) comprises a heat transfer region (30), and the upper end portion (8) comprises first and second port holes (10, 12), an upward distribution region (14), and a second boundary line (bl1) adjacent to the upward distribution region (14) along a first boundary line (bl1). 2) The lower end portion (18) comprises a third and fourth port hole (20, 22), a downward distribution region (24), and a downward distribution region (26) adjacent to the downward distribution region (24) along the third boundary line (bl3) and adjacent to the heat transfer region (30) along the fourth boundary line (bl4). The upper distribution region (14) is provided with a distribution pattern (48), the upward distribution region (16) is provided with a transfer pattern (50), and the heat transfer region (30) is provided with a heat transfer pattern (52). The transition pattern (50) differs from the distribution pattern (48) and the heat transfer pattern (52) in that the transition pattern (50) comprises support transition peaks (60) and support transition valleys (62) that are alternately arranged when viewed from the front side (4) of the heat transfer plate (2a), the upper portion (60t) of each of at least a plurality of support transition peaks (60) extending in a first plane (P1), and the bottom portion (62b) of each of at least a plurality of support transition valleys (62) extending in a second plane (P2), and the infinite virtual transition line (68) is the support transition peak ( 60) and extending through two opposite endpoints (70, 72) of each of the support transition valleys (62), the heat transfer plate (2a) defines a plurality of separate virtual transition lines (68), and the heat transfer plate (2a) further comprises a front gasket groove (46) having a front gasket groove portion (46a) that surrounds the heat transfer region (30), the upper and lower transition regions (16, 26), the upper and lower distribution regions (14, 24), and two of the first, second, third, and fourth port holes (10, 12, 20, 22) on the front side (4),The bottom (55) of the front gasket groove (46) extends between the first and second planes (P1, P2) along at least half the length of the front gasket groove portion (46a) of the region, The heat transfer plate (2a) is characterized in that the virtual transfer line (68) extends parallel to the longitudinal central axis (L) of the heat transfer plate (2a) with respect to at least a plurality of the support transfer peaks (60) and support transfer valleys (62).

2. The heat transfer plate (2a) according to claim 1, wherein the bottom (55) of the front gasket groove (46) is parallel to the first and second planes (P1, P2) and extends along a central plane (CP) that extends in half the distance between the first and second planes (P1, P2) for at least half the length of the front gasket groove portion (46a).

3. The heat transfer plate (2a) according to claim 1 or 2, wherein at least a plurality of the support transition peaks (60) and support transition valleys (62) are elongated and / or straight.

4. The heat transfer plate (2a) according to any one of claims 1 to 3, wherein the virtual transfer line (68) coincides with the longitudinal central axis (lt) of each of the support transfer peaks (60) or support transfer valleys (62) for at least one of the plurality of support transfer peaks (60) and support transfer valleys (62).

5. The heat transfer plate (2a) according to any one of claims 1 to 4, wherein at least a plurality of the virtual transfer lines (68) defined by the heat transfer plate (2a) extend through only one of the support transfer peaks (60) and the support transfer valleys (62).

6. The heat transfer plate (2a) according to any one of claims 1 to 5, wherein the center points (c) of at least a plurality of the support transition peaks (60) and support transition valleys (62) are positioned on a virtual center line (cl) that intersects the longitudinal central axis (L) of the heat transfer plate (2a).

7. A heat transfer plate (2a) according to any one of claims 1 to 6, wherein the number of virtual transition lines (68) is an even number x.

8. The transition pattern (50) further comprises turbulent transition peaks (74) and turbulent transition valleys (76), wherein the upper portion (74t) of each of the turbulent transition peaks (74) extends in a third plane (P3) which is arranged parallel to the first and second planes (P1, P2) between the first and second planes (P1, P2), and the bottom portion (76b) of each of the turbulent transition valleys (76) extends between the second and third planes (52, 72). A heat transfer plate (2a) according to any one of claims 1 to 7, extending in a fourth plane (P4) arranged parallel to the second and third planes (52, 72), wherein at least a plurality of the turbulent transfer peaks and turbulent transfer valleys (74, 76) are alternately arranged in the gaps (78) between the virtual transfer lines (68), and connecting the supporting transfer peaks (60) and supporting transfer valleys (62) with respect to adjacent virtual transfer lines (68).

9. The heat transfer plate (2a) according to claim 8, wherein at least a plurality of the turbulent transition peaks (74) and turbulent transition valleys (76) extend inclined with respect to the transverse central axis (T) of the heat transfer plate (2a) along at least the central portions (74a, 76a) of their longitudinal extensions.

10. The heat transfer plate (2a) according to claim 8 or 9, wherein at least a plurality of the turbulent transfer peaks (74) and turbulent transfer valleys (76) that are fully positioned on the first half (38) of the heat transfer plate (2a) along the central portion (74a, 76a) extend clockwise with respect to the transverse central axis (T) of the heat transfer plate (2a) at a minimum angle α of 0 < α < 90, and the remainder of the at least a plurality of the turbulent transfer peaks (74) and turbulent transfer valleys (76) along the central portion (74a, 76a) extend counterclockwise with respect to the transverse central axis (T) of the heat transfer plate (2a) at a minimum angle β of 0 < β < 90.

11. The heat transfer plate (2a) according to claim 10, wherein α is equal to β.

12. The heat transfer plate (2a) according to any one of claims 1 to 11, wherein the upward transition region (16) and the downward transition region (26) are symmetrical to at least 50 percent with respect to the transverse central axis (T) of the heat transfer plate (2a).

13. The heat transfer pattern (52) comprises support HT peaks (80) and support HT valleys (82), and at least a plurality of the support HT peaks (80) and support HT valleys (82) extend longitudinally parallel to the longitudinal central axis (L) of the heat transfer plate (2a), and at least the upper portion (80t) of each of the plurality of support HT peaks (80) extends in the first plane (P1), and at least the bottom portion (82b) of each of the plurality of support HT valleys (82) extends in the second plane (P2), at The plurality of support HT peaks (80) and support HT valleys (82) are alternately arranged along several separate virtual longitudinal HT lines (84) extending parallel to the longitudinal central axis (L) of the heat transfer plate (2a), and along several separate virtual transverse HT lines (86) extending parallel to the transverse central axis (T) of the heat transfer plate (2a), and at least a plurality of the support HT peaks (80) and support HT valleys (82) are centered relative to the virtual longitudinal HT lines (84). The heat transfer pattern (52) extends between adjacent virtual transverse HT straight lines (86), and further comprises turbulent HT peaks (88) and turbulent HT valleys (90), with at least a plurality of the upper portions (88t) of each of the turbulent HT peaks (88) extending in a fifth plane (P5) arranged parallel to the first and second planes (P1, P2) between the first and second planes (P1, P2), and at least a plurality of the bottom portions (90b) of each of the turbulent HT valleys (90) being the second and A heat transfer plate (2a) according to any one of claims 1 to 12, extending in a sixth plane (P6) arranged parallel to the second and fifth planes (P2, P5) between the fifth planes (P2, P5), wherein at least a plurality of turbulent HT peaks and turbulent HT valleys (88, 90) are alternately arranged in the gaps (92) between the virtual longitudinal HT lines (84), and connecting the supporting HT peaks (80) and supporting HT valleys (82) along adjacent virtual longitudinal HT lines (84).

14. The heat transfer plate (2a) according to claim 13, wherein at least a plurality of the virtual longitudinal HT lines (84) coincide with one of the virtual transition lines (68).

15. The heat transfer plate (2a) according to claim 13 or 14, wherein the longitudinal extension of at least a plurality of the support transition peaks (60) and support transition valleys (62) is smaller than the longitudinal extension of the support HT peaks (80) and support HT valleys (82).

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