A heat exchanger plate and a plate heat exchanger

Abstract

The disclosure relates to a heat exchanger plate (1a, 1b) for a plate heat exchanger (2), the heat exchanger plate (1a, 1b) is divided into a left half (6) and a right half (6) by a longitudinal center axis (Y), which left half (4) and right half (6) are delimited by a first long side (8) and second long side (10), respectively, and wherein the heat exchanger plate (1a, 1b) further is divided into an upper half (12) and a lower half (14) by a transverse center axis (X), which upper half (12) and a lower half (14) are delimited by a first short side (16) and second short side (18), respectively, and wherein the heat exchanger plate (1a, 1b) comprises a porthole (20a) arranged within the left half (4) and the upper half (12). The shape of the porthole (20a) is defined by a number of circular arcs (A1, A2, A3, A4, A5), wherein individual radiuses (R1, R2, R3, R4, R5) of the circular arcs (A1, A2, A3, A4, A5) have a sequence of decreasing and increasing relationships in a clockwise direction of the porthole (20a) starting from the largest radius (R1, R2, R3, R4, R5). The disclosure further relates to a plate heat exchanger (2).

Description

[0001] A heat exchanger plate and a plate heat exchanger

[0002] Technical field

[0003] The present disclosure relates to a heat exchanger plate for a plate heat exchanger and a plate heat exchanger. More specifically, the disclosure relates to a heat exchanger plate for a plate heat exchanger and a plate heat exchanger as defined in the introductory parts of the independent claims.

[0004] Background art

[0005] Plate heat exchangers, which are permanently joined to each other, do not require separate sealings between the plates and no external frame to hold the plates together. Instead of an external frame, the plates can be permanently joined by brazing, soldering, welding or gluing. The joints between the plates have a pressure bearing function and can thus resist pressures from the heat exchange medium in the plate heat exchangers. Joints may be formed by a joining method in which the plates are subjected to a heat lower than the melting point of the plates. Such joining methods may be one of brazing with an added brazing material in the form of a foil, a paste, or a powder comprising e.g., copper or nickel, or joining by means of the material of the plates by application of a melting depressant composition applied to the plates prior to being heated.

[0006] The inlet and outlet channels in the port portions of the plates have large projected areas and are provided with connecting joints between the heat exchanger plates. In order to enable a large volume flow of the heat exchange medium though the plate heat exchanger, the diameter of the inlet and outlet channels is increased, so that the exposed area of the channels in direction of flow passages in the heat exchanger increases. Further, the flow of the heat exchange medium between the plates in the heat exchanger is more evenly distributed when the diameter of the inlet and outlet channels is increased.

[0007] Document EP2728293 A1 discloses a plate heat exchanger comprising heat exchanger plates, which are provided with portholes with a reference point coinciding with a center point of a biggest imaginary circle that can be fitted into the port hole. The portholes are defined by a number of corner points of an imaginary plane geometric figure of which at least one is displaced from an arc of the circle. A number of thoroughly curved lines connect the corner points. A first corner point of the corner points is arranged closest to a transition between a first short side and a first long side of the plate, and on a first distance from the reference point A second one of the corner points is arranged corner point in a clockwise direction and on a second distance from the reference point. A third one of the corner points is arranged closest to the first corner point in a counter clockwise direction and on a third distance from the reference point. Such a heat exchanger plate is associated with a relatively low pressure drop and can be used in connection with relatively less powerful peripheral equipment.

[0008] Summary

[0009] Distribution of the heat exchange medium from the portholes in the heat exchanger plates to the flow passages in the plate heat exchanger is critical, since the distribution of the heat exchange medium to the flow passages affects the heat transfer performance of the plate heat exchanger. An uneven distribution of the heat exchange medium in the flow passages may decrease the heat transfer performance and also result in a pressure drop in the plate heat exchanger.

[0010] Despite known solutions in the field, it would be desirable to develop a plate heat exchanger, which overcome or alleviate at least some of the issues connected to the prior art plate heat exchangers.

[0011] It is an objective of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified issues of the prior art and solve at least the above- mentioned difficulties.

[0012] Further, it is an objective of the present invention is to provide a plate heat exchanger with increased heat exchange performance.

[0013] These objectives are achieved with the above-mentioned heat exchanger plate and the plate heat exchanger according to the appended claims.

[0014] According to a first aspect there is provided a plate heat exchanger comprising a heat exchanger plate, the heat exchanger plate is divided into a left half and a right half by a longitudinal center axis, which left half and right half are delimited by a first long side and second long side, respectively, and wherein the heat exchanger plate further is divided into an upper half and a lower half by a transverse center axis, which upper half and a lower half are delimited by a first short side and second short side, respectively, and wherein the heat exchanger plate comprises a porthole arranged within the left half and the upper half. The shape of the porthole is defined by a number of circular arcs, wherein individual radiuses of the circular arcs have a sequence of decreasing and increasing relationships in a clockwise direction of the porthole starting from the largest radius. The heat exchanger plate may be symmetrically or asymmetrically shaped relation to the longitudinal and transverse axis. The longitudinal and transverse axis of the heat exchanger plate may be a part of the heat exchange plate. The longitudinal and transverse axis of the heat exchanger plate may not be a part of the heat exchange plate. The longitudinal and transverse axis of the heat exchanger plate may not be a physical entity but only axis to which physical parts of the heat exchanger plate may relate to. The porthole arranged within the left half and the upper half. Further portholes may be arranged in the heat exchanger plate. A further porthole may be arranged in the right half and the upper half, in left half and the lower half, and in the right half and the lower half. Thus, four portholes may be arranged in the heat exchanger plate. The circular arc is defined by part of the circular periphery of a circle. The number of circular arcs together define the circumferential of the porthole. Arranging the number of circular arcs with individual radiuses, which are different from each other, in a sequence of decreasing and increasing relationships in a clockwise direction of the porthole, starting from the largest radius may define a shape of the porthole, which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged. Such shape of the porthole is beneficial for an even distribution of the heat exchange medium in flow passages of the plate heat exchanger, which may reduce or eliminate any pressure drop in the plate heat exchanger. Further, turbulence in the flow of the heat exchange medium in the flow passages may be reduced or eliminated as a result of the shape of the portholes, which will increase the heat transfer performance of the plate heat exchanger. Distribution of the heat exchange medium from the portholes in the heat exchanger plates to the flow passages in the plate heat exchanger may in different situations be critical, since the distribution of the heat exchange medium to the flow passages affects the heat transfer performance of the plate heat exchanger. An uneven distribution of the heat exchange medium in the flow passages may decrease the heat transfer performance and also result in a pressure drop in the plate heat exchanger. Further, when increasing the overall dimensions of the plate heat exchanger, the flow of the heat exchange medium in the flow passages may be subjected to turbulence affecting the heat transfer performance of the plate heat exchanger. The plate heat exchanger may comprise a number of heat exchanger plates, which are arranged above each other between an upper, outer cover plate and a lower, outer cover plate. The portholes of the heat exchanger plates are aligned, so that they form an inlet channel and an outlet channel, which at the bottom are limited by the lower, outer cover plate and which at the top communicate with an inlet pipe and an outlet pipe, respectively. The heat exchanger may have one inlet channel and one outlet channel for a first and a second heat exchange medium, which inlet and outlet channels may be located in the end portions of the heat exchanger plates. The heat exchanger can alternatively be provided with several inlet or outlet channels. The location of the channels can be chosen freely. The flow of the first and second heat exchange medium may be in parallel in the heat exchanger. However, the first inlet and outlet channels may be diagonally arranged in relation to the parallel flow in the heat exchanger. Further, the second inlet and outlet channels may be diagonally arranged in relation to the parallel flow in the heat exchanger. Alternatively, the first inlet and outlet channels may be aligned in relation to the parallel flow in the heat exchanger. Further, the second inlet and outlet channels may be aligned in relation to the parallel flow in heat exchanger. The number of heat exchanger plates of the heat exchanger form together a package of heat exchanger plates. The heat exchanger plates may have a rectangular form, but other forms could be possible, such as round heat exchanger plates. The number of heat exchanger plates of the heat exchanger is depending on desired capacity. For the joining of the heat exchanger a suitable amount of plates are piled on each other, whereupon adjacent plates are joined together by brazing, soldering, welding or gluing. Adjacent heat exchanger plates are permanently joined to each other. Therefore, no separate gaskets are required between the plates and neither any outer frame to hold the plates together. The expression permanently joined refers mainly to brazing, but also for example soldering, welding or gluing. Joints may be formed by a joining method in which the plates are subjected to a heat lower than the melting point of the plates. Such joining methods may be one of brazing with an added brazing material in the form of a foil, a paste, or a powder comprising e.g., copper or nickel, or joining by means of the material of the plates by application of a melting depressant composition applied to the plates prior to being heated. The peripheral portion of the heat exchanger plates may be provided with a flank and a brim. The flank of one heat exchanger plates may be joined to the flank of one adjacent heat exchanger plate. The joined flanks will ensure a fluid tight connection along the peripheral portion of the heat exchanger plates. The brim increases the stiffness and overall strength of the plate heat exchanger. The brim may however be excluded from the heat exchanger plate. Flow passages are configured between adjacent plates. In the flow passages the heat exchange medium flows through the plate heat exchanger. Adjacent heat exchanger plates are connected and bounded together at several positions on their surfaces. Between these bonding positions, the flow passages are left. A heat exchange portion is arranged between adjacent plates and between the end portions of the heat exchanger. In the heat exchange portion heat is transferred from one of the heat exchange medium to the other heat exchange medium. Stacking the individual heat exchanger plates on each other will align the through flow portholes of the plates. The aligned through flow portholes form inlet and outlet channels through the package of plates. The first inlet and outlet channels communicate with every other flow passage between the heat exchanger plates. The second inlet and outlet channels communicate with the remaining flow passages between the heat exchanger plates. There is only heat exchange between every other flow passage and the remaining flow passages but no fluid communication between these separated passages.

[0015] The number of circular arcs are five circular arcs: a first circular arc with a first radius, a second circular arc with a second radius, a third circular arc with a third radius, a fourth circular arc with a fourth radius and a fifth circular arc with a fifth radius arranged in sequence in a clockwise direction of the porthole. The five circular arcs may have different radiuses. Arranging the five circular arcs with individual radiuses, which are different from each other, in such a sequence will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged.

[0016] The sequence of decreasing and increasing relationships of the individual radiuses of the circular arcs may be: first radius > second radius; second radius < third radius; third radius > fourth radius; fourth radius < fifth radius. Thus the first radius may be larger than the second radius, the second radius may be smaller than the third radius, the third radius may be larger than the fourth radius, and the fourth radius may be smaller than the fifth radius. Arranging the five circular arcs in such a sequence will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged. The second radius may be in the range of 17 - 23% of the first radius, the third radius may be in the range of 84 - 90% of the first radius; the fourth radius may be in the range of 28 - 34 % of the first radius, and the fifth radius may be in the range of 41 - 47% of the first radius. Arranging the five circular arcs within these ranges in relation to each other will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged.

[0017] The second radius may be 19,7% of the first radius, the third radius may be 87,5% of the first radius; the fourth radius may be 31 ,2 % of the first radius, and the fifth radius may be 43,8% of the first radius. Such relation of the radiuses of the circular arcs will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged. The first radius may be 80 mm. When defining a value of the first radius, also the values of the second, third, fourth and the fifth radiuses are defined by the above mentioned ranges and relations. The value of the first radius may depend on the expected performance and capacity of the plate heat exchanger in which the heat exchanger plates are arranged. A value of 80 mm of the first radius may create a porthole with a shape, which is adapted to a heat exchanger plate with dimensions that create a plate heat exchanger with a performance and capacity defined by such shape and size of the portholes.

[0018] The second circular arc may be arranged closest to the longitudinal center axis in relation to the first circular arc, the third circular arc, the fourth circular arc and the fifth circular arc. Arranging the second circular arc closest to the longitudinal center axis may position the porthole in the heat exchanger plate so that the heat exchanging media can pass through the portholes and the flow passages in the plate heat exchanger with a low pressure drop and a large heat exchange performance. The position of the third circular arc in relation to the second circular arc in the heat exchanger plate, when second circular arc is arranged closest to the longitudinal center axis may be favorable for the passage of the heat exchanger media to pass through the portholes and further the flow passages in the plate heat exchanger. Another way to define the position of the porthole in the heat exchanger plate is to introduce an imaginary circle, wherein the fifth circular arc is a part of the imaginary circle. The fifth circular arc may have a center point in common with the imaginary circle. A peripheral portion of the heat exchanger plate may be provided with rounded corners. The rounded corner positioned at the left half and the upper half of the heat exchanger plate may represent a sixth circular arc with a radius. The sixth circular arc may have the center point in common with the fifth circular arc.

[0019] The fourth circular arc may be arranged closest to the transverse center axis in relation to the first circular arc, the second circular arc, the third circular arc, and the fifth circular arc. Arranging the fourth circular arc closest to the transverse center axis may position the porthole in the heat exchanger plate so that the heat exchanging media can pass through the portholes and the flow passages in the plate heat exchanger with a low pressure drop and a large heat exchange performance. The position of the third circular arc in relation to the fourth circular arc in the heat exchanger plate, when third circular arc is arranged closest to the transverse center axis may be favorable for the passage of the heat exchanger media to pass through the portholes and further the flow passages in the plate heat exchanger.

[0020] The plate comprises a port portion arranged adjacent to the porthole, wherein guiding ribs are arranged in the port portion, which guiding ribs are configured to define fluid guide channels between the porthole and a heat exchange portion of the plate, and wherein the fluid guide channels open at the position of the third circular arc. The port portions may surround the inlet or outlet channels formed by the portholes. The port portions may be placed in the two end planes of the plates, located furthest from each other. The guiding ribs may be configured as separate parts or as integral parts of the heat exchanger plate. The guiding ribs are arranged at the port portions of the plates. The guiding ribs may extend between the area of the portholes and the area of the heat exchange portion. The guiding ribs may be configured to guide the first and second heat exchange medium in both directions along and between the ribs. When the heat exchange medium flows in the direction from the portholes to the heat exchange portion, the heat exchange medium will be spread out at a larger area than the area at the porthole. When the heat exchange medium flows in the direction from the heat exchange portion to the portholes, the heat exchange medium will be concentrated to a smaller area than the area at the heat exchange portion. The plate heat exchanger provided with the above-mentioned guiding ribs will increase the heat exchange performance of the plate heat exchanger.

[0021] The shape of the porthole defined by a number of circular arcs is beneficial compared to other shapes, i.e. , circular ports, especially in very compact designs. In such units, the distribution area is quite small compared to the heat transfer area so using the above-mentioned shape allows for a better utilization of the distribution area and works in synergy with the ribs to guarantee an improved flow distribution before the fluid enters the fins at the heat transfer area where no mixing occurs due to the micro-channels they form. Moreover, the above-mentioned shape allows for a smaller buoyancy effect under the port compared to for example, a circular one, which if this (the port) is located relatively close to the inlet of the fin area because of the compact design, it can create a shadow effect and block the entrance of the fluid into some fins, and thus, loosing effective heat transfer area.

[0022] The first circular arc has a first arc length, the second circular arc has a second arc length, the third circular arc has a third arc length, the fourth circular arc has a fourth arc length, and the fifth circular arc has a fifth arc length, wherein the second arc length is 65% of the first arc length, the third arc length is 153% of the first arc length, the fourth arc length is 83 % of the first arc length and the fifth arc length is 134% of the first arc length. These relative lengths between the arc lengths will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged. According to an example the first circular arc may have a first arc length of 39,8 mm, the second circular arc may have a second arc length of 26 mm, the third circular arc may have a third arc length of 61 mm, the fourth circular arc may have a fourth arc length of 33 mm, and the fifth circular arc may have a fifth arc length of 53,3 mm.

[0023] The first circular arc may be connected to the second circular arc at a first point, the second circular arc may be connected to the third circular arc at a second point, the third circular arc may be connected to the fourth circular arc at a third point, and the fourth circular arc may be connected to the fifth circular arc at a fourth point. The connection between the circular arcs at the above-mentioned points results in a coherent number of circular arcs, which together defines the shape of the porthole.

[0024] A first distance is defined between the first point and the third point , a second distance is defined between the first point and the fourth point, a third distance is defined between the second point and the fourth point, a fourth distance is defined between the second point and the fifth point, and a fifth distance is defined between the third point and the fifth point, wherein the second distance is 115% of the first distance, the third distance is 112% of the first distance, the fourth distance is 78% of the first distance, the fifth distance is 91 % of the first distance. These relative distances between the connection points of the circular arcs will create a shape of the porthole which is beneficial for the heat transfer performance of the plate heat exchanger in which such heat exchanger plates are arranged. According to an example the first distance between the first point and the third point may be 69,7 mm, the second distance between the first point and the fourth point may be 80,3 mm, the third distance between the second point and the fourth point may be 78 mm, the fourth distance between the second point and the fifth point may be 54,4 mm, and the fifth distance between the third point and the fifth point may be 63,7 mm.

[0025] The transition between the circular arcs, which are adjacent to each other, may be so arranged that there is a tangential constraint between the adjacent circular arcs. The tangential constraint between the adjacent circular arcs results in a smooth transition between the circular arcs. Such shape of the portholes will increase the strange of the portholes. Such shape of the portholes results in that the portholes can withstand large pressures from the heat exchange medium.

[0026] The guiding ribs of the plate heat exchanger may be straight and extend in an oblique angle relative to the longitudinal axis. The guiding ribs may further be formed as corrugations in the heat exchanger plate. The guide ribs will allow the heat exchange medium to spread out at a larger area than the area at the porthole and provide well defined contact points for guiding ribs of an opposing heat exchanger plate.

[0027] A number of the guiding ribs, such as all of the guiding ribs or all of the guiding ribs except the outermost guiding ribs, may extend to a position at a distance from a respective end portion of the fins. The resulting gap may be configured as a mixing zone. The mixing zone will allow the fluid to mix better and achieve an even and thereby technically desired fluid distribution in the heat exchange portion. The mixing zone should be kept small as in this area there is no mechanical support between the plates.

[0028] The outermost guiding ribs may extend into the mixing zone and abut against the respective end portion of the fins. In this way the fins are held in place and a well- defined distance between the ribs and the fins is established for the mixing zone. The plate heat exchanger may comprise at least two opposing heat exchanger plates with opposing guiding ribs contacting each other to establish the guide channels. The guiding ribs of opposing heat exchanger plates may form a cross-corrugated pattern. The guiding ribs may be brazed together at contact points where guiding ribs of opposing heat exchanger plates contact each other.

[0029] The plate heat exchanger may comprise a number of heat exchanger plates, which are arranged above each other between an upper, outer cover plate and a lower, outer cover plate. The portholes of the heat exchanger plates are aligned, so that they form an inlet channel and an outlet channel, which at the bottom are limited by the lower, outer cover plate and which at the top communicate with an inlet pipe and an outlet pipe, respectively. The heat exchanger may have one inlet channel and one outlet channel for a first and a second heat exchange medium, which inlet and outlet channels may be located in the end portions of the heat exchanger plates. The heat exchanger can alternatively be provided with several inlet or outlet channels. The location of the channels can be chosen freely. The flow of the first and second heat exchange medium may be in parallel in the heat exchanger. However, the first inlet and outlet channels may be diagonally arranged in relation to the parallel flow in the heat exchanger. Further, the second inlet and outlet channels may be diagonally arranged in relation to the parallel flow in the heat exchanger. Alternatively, the first inlet and outlet channels may be aligned in relation to the parallel flow in the heat exchanger. Further, the second inlet and outlet channels may be aligned in relation to the parallel flow in heat exchanger. The number of heat exchanger plates of the heat exchanger form together a package of heat exchanger plates. The heat exchanger plates may have a rectangular form, but other forms could be possible, such as round heat exchanger plates. The number of heat exchanger plates of the heat exchanger is depending on desired capacity. Flow passages are configured between adjacent plates. In the flow passages the heat exchange medium flows through the plate heat exchanger. A heat exchange portion is arranged between adjacent plates and between the end portions of the heat exchanger. In the heat exchange portion heat is transferred from one of the heat exchange medium to the other heat exchange medium. Stacking the individual heat exchanger plates on each other will align the through flow portholes of the plates. The aligned through flow portholes form inlet and outlet channels through the package of plates. The first inlet and outlet channels communicate with every other flow passage between the heat exchanger plates. The second inlet and outlet channels communicate with the remaining flow passages between the heat exchanger plates. There is only heat exchange between every other flow passage and the remaining flow passages but no fluid communication between these separated passages.

[0030] The heat exchanger is a permanently bonded heat exchanger. For the joining of the heat exchanger a suitable amount of plates are piled on each other, whereupon adjacent plates are joined together by brazing, soldering, welding or gluing. Adjacent heat exchanger plates are permanently joined to each other. Therefore, no separate gaskets are required between the plates and neither any outer frame to hold the plates together. The expression permanently joined refers mainly to brazing, but also for example soldering, welding or gluing. Joints may be formed by a joining method in which the plates are subjected to a heat lower than the melting point of the plates. Such joining methods may be one of brazing with an added brazing material in the form of a foil, a paste, or a powder comprising e.g., copper or nickel, or joining by means of the material of the plates by application of a melting depressant composition applied to the plates prior to being heated. The peripheral portion of the heat exchanger plates may be provided with a flank and a brim. The flank of one heat exchanger plates may be joined to the flank of one adjacent heat exchanger plate. The joined flanks will ensure a fluid tight connection along the peripheral portion of the heat exchanger plates. The brim increases the stiffness and overall strength of the plate heat exchanger. The brim may however be excluded from the heat exchanger plate. Adjacent heat exchanger plates are connected and bounded together at several positions on their surfaces. Between these bonding positions, the flow passages are left.

[0031] Fins are arranged in the heat exchange portion, which fins are configured to create a number of parallel fin channels for a heat exchange medium. The fins may create a number of parallel fin channels for the heat exchange medium. The fins may guide the flow of the heat exchange medium in parallel through the heat exchange portion. The fins may be made of thermally conductive material, such as steel or an aluminum alloy. A number of individual fins may be arranged in parallel in the heat exchange portion, extending in a longitudinal direction of the heat exchanger, and creating fin channels between the individual fins. Alternatively, the individual fins may be connected to each other. Each parallel fin channel may be delimited by walls of the fins and a heat exchanger plate. Each fin may extend between two adjacent heat exchanger plates. The surfaces of the two adjacent plates and the surfaces of two adjacent fins may define one fin channel. The fins may be brazed, soldered, welded or glued to the surfaces of two adjacent plates. The distance between the fins and the distance between the plates affects the shape and size of the cross-sectional area of the individual guide channel. The distance between the fins may also decide the number of fins and channels in the heat exchange portion. The shape and the size of the cross-sectional area of the individual fin channel may have an impact on the volume flow of the heat exchange medium in the guide channel. The fins may be created by a corrugated sheet metal, which has wave peaks and wave troughs. The fins may be created by a pleated sheet of thermally conductive material. The fins may have a wave shape. The parallel guide channels may be created between wave peaks and between wave troughs of the wave shaped fins.

[0032] The shape of the ports is critical in relation to the fins being arranged in the heat exchange portion because it is necessary to have an even flow distribution before the fluid enters the heat exchange portion provided with the fins. Tthe fluid distribution will not change when the fluid is inside the flow channels as the fluid cannot flow between the flow channels. In a normal herringbone pressed plate there are no separated flow channels and thus the flow distribution is not as critical as the fluid can distribute itself even after entering the heat exchange portion. Thus, the non-circular shape of the port hole allows to create more space for a pattern in the distribution area and to facilitate flow around the ports. Further, the risk of dead spots and thermal stresses is reduced.

[0033] Additional objectives, advantages and novel features of the invention will be apparent to one skilled in the art from the following details, and through exercising the invention. While the invention is described below, it should be apparent that the invention may not be limited to the specifically described details. One skilled in the art, having access to the teachings herein, will recognize additional applications, modifications and incorporations in other areas, which are within the scope of the invention.

[0034] Brief descriptions of the drawings

[0035] The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

[0036] Fig. 1 schematically illustrates a heat exchanger plate in a view from above according to a first example;

[0037] Fig. 2 schematically illustrates a heat exchanger plate in a view from above according to a second example;

[0038] Fig. 3 schematically illustrates a perspective view of an upper half of four heat exchanger plates arranged in a package;

[0039] Fig. 4 schematically illustrates a plate heat exchanger in a perspective view according to an example;

[0040] Fig. 5 schematically illustrates a package of the four heat exchanger plates in a section view along line A - A in fig. 4 according to an example;

[0041] Fig. 6 schematically illustrates the package of the four heat exchanger plates in a section view along line B - B in fig. 4 according to an example; and

[0042] Figures 7 - 9 schematically illustrate the portholes of a heat exchanger plate in a detail view according to an example.

[0043] Detailed description

[0044] The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

[0045] Fig. 1 schematically illustrates a heat exchanger plate 1a in a view from above according to a first example. Heat exchanger plates 1a according to the first example in fig. 1 are configured to be arranged in a package together with heat exchanger plates 1 b according to a second example in fig. 2. The package of a number of heat exchanger plates 1a, 1 b will form a plate heat exchanger 2, which will be described in connection with fig. 4. A vertical or longitudinal center axis Y divides the heat exchanger plate 1a into a left half 4 and a right half 6 delimited by a first long side 8 and second long side 10, respectively. A horizontal or a transverse center axis X divides the heat exchanger plate 1a into an upper half 12 and a lower half 14 delimited by a first short side 16 and second short side 18, respectively. A porthole 20a is arranged within the left half 4 and the upper half 12. A porthole 21a is also arranged within the right half 4 and the upper half 12. Portholes 20a, 21a are also arranged correspondingly within the lower half 14. The plate 1a comprises a port portion 22a arranged adjacent to the portholes 20a, 21a, wherein guiding ribs 24a are arranged in the port portion 22a, which guiding ribs 24a are configured to define fluid guide channels 26a between the porthole 20a and a heat exchange portion 28a of the plate 1a.

[0046] Fig. 2 schematically illustrates a heat exchanger plate 1 b in a view from above according to a second example. The guiding ribs 24b in the port portion 22b of the heat exchanger plate 1 b according to the second example are arranged in a mirror shaped pattern in relation to the guiding ribs 24a in the heat exchanger plate 1a according to the first example. The heat exchanger plate 1 b according to the second example comprises a heat exchange portion 28b. When arranging the heat exchanger plate 1a according to the first example on the heat exchanger plate 1b according to the second example, flow passages for a first and second heat exchange medium 34, 35 (fig. 4) are created in spaces between the heat exchanger plates 1a, 1 b according to the first and second examples. Four portholes 20b, 21b are arranged in the heat exchanger plate 1 b according to the second example.

[0047] Fig. 3 schematically illustrates a perspective view of an upper half of four heat exchanger plates 1a, 1 b arranged in a package. The portholes 20a, 20b, 21a, 21b of the heat exchanger plates 1a, 1 b are aligned and sealingly connected. A peripheral portion 36 of the heat exchange plates 1a, 1 b are provided with a flank 23 and are sealingly connected. Fins 30 are arranged in the heat exchange portions 28a, 28b, which fins 30 are configured to create a number of parallel fin channels 32.

[0048] Figure 4 schematically illustrates a plate heat exchanger 2 in a perspective view according to an example. The plate heat exchanger 2 comprising a package of heat exchanger plates 1a, 1 b, each having four portholes 20a, 21a, 20b, 21 b. The heat exchanger plates 1a, 1 b are permanently joined to adjacent heat exchanger plates 1a, 1 b of the package along their peripheral portions 36 in such manner that they leave flow passages in port portions 22a, 22b and heat exchange portions 28a, 28b between adjacent heat exchanger plates 1a, 1 b. The portholes 20a of the heat exchanger plates 1a, 1 b are aligned and form first inlet and outlet channels 38, 39 through the package for the first heat exchange medium 34, which communicate with every other flow passages 22a, 22b, 28a, 28b between the heat exchanger plates 1a, 1b, and second inlet and outlet channels 40, 41 through the package, formed by the portholes 21a for the second heat exchange medium 35, which communicate with remaining flow passages 22a, 22b, 28a, 28b between the heat exchanger plates 1a, 1 b.

[0049] Fig. 5 schematically illustrates a package of the four heat exchanger plates 1a, 1 b in a section view along line A - A in fig. 4 according to an example. The heat exchanger plates 1a, 1 b are permanently joined to adjacent heat exchanger plates 1a, 1 b of the package along their peripheral portions 36 in such manner that they leave flow passages in the heat exchange portion 28a, 28b between adjacent heat exchanger plates 1a, 1 b. Fins 30 are arranged in the heat exchange portion 28a, 28b, which fins 30 are configured to create a number of parallel fin channels 32 for each of the first and second heat exchange medium 34, 35, respective. The peripheral portion 36 of each heat exchange plate 1a, 1 b is provided with a flank 23.

[0050] Fig. 6 schematically illustrates the package of the four heat exchanger plates 1a, 1 b in a section view along line B - B in fig. 4 according to an example. The connection between the heat exchanger plates 1a, 1 b creates according to this example a solid line 42 around the first inlet channel 38 and a solid line 44 around the second outlet channel 41 , respectively. The second outlet channel 41 communicate with every other flow passage between the heat exchanger plates 1a, 1b. The first inlet channel 38 communicates with the remaining flow passages between the heat exchanger plates 1a, 1 b.

[0051] Figures 7 - 9 schematically illustrate the portholes 20a, 21a of the heat exchanger plate 1a in detail views according to examples. The shape of the porthole 20a is defined by a number of circular arcs A1 , A2, A3, A4, A5, wherein individual radiuses R1 , R2, R3, R4, R5 of the circular arcs A1 , A2, A3, A4, A5 have a sequence of decreasing and increasing relationships in a clockwise direction of the porthole 20a starting from the largest radius R1 , R2, R3, R4, R5. The number of circular arcs A1 , A2, A3, A4, A5 are five circular arcs A1 , A2, A3, A4, A5: a first circular arc A1 with a first radius R1 , a second circular arc A2 with a second radius R2, a third circular arc A3 with a third radius R3, a fourth circular arc A4 with a fourth radius R4 and a fifth circular arc A5 with a fifth radius R5 arranged in sequence in a clockwise direction of the porthole 20a. The first circular arc A1 is connected to the second circular arc A2 at a first point P1 , the second circular arc A2 is connected to the third circular arc A3 at a second point P2, the third circular arc A3 is connected to the fourth circular arc A4 at a third point P3, and the fourth circular arc A4 is connected to the fifth circular arc A5 at a fourth point P4. the transition between the circular arcs A1 , A2, A3, A4, A5, which are adjacent to each other, are so arranged that there is a tangential constraint between the adjacent circular arcs A1 , A2, A3, A4, A5.

[0052] The sequence of decreasing and increasing relationships of the individual radiuses R1 , R2, R3, R4, R5 of the circular arcs A1 , A2, A3, A4, A5 are: first radius R1 > second radius R2; second radius R2 < third radius R3; third radius R3 > fourth radius R4; fourth radius R4 < fifth radius R5.

[0053] The second radius R2 is in the range of 17 - 23% of the first radius R1 , the third radius R3 is in the range of 84 - 90% of the first radius R1 ; the fourth radius R4 is in the range of 28 - 34 % of the first radius R1 , and the fifth radius R5 is in the range of 41 - 47% of the first radius R1. According to another example the second radius R2 is 19,7% of the first radius R1 , the third radius R3 is 87,5% of the first radius R1 ; the fourth radius R4 is 31 ,2 % of the first radius R1 , and the fifth radius R5 is 43,8% of the first radius R1 . The first radius R1 may according to an example be 80 mm.

[0054] The second circular arc A2 is arranged closest to the longitudinal center axis Y in relation to the first circular arc A1 , the third circular arc A3, the fourth circular arc A4 and the fifth circular arc A5. The fourth circular arc A4 is arranged closest to the transverse center axis X in relation to the first circular arc A1 , the second circular arc A2, the third circular arc A3, and the fifth circular arc A5.

[0055] The port portion 22 is arranged adjacent to the porthole 20a, comprising the guiding ribs 24, which define fluid guide channels 26 between the porthole 20a and a heat exchange portion 28 of the plate 1 . The fluid guide channels 26 open at the position of the third circular arc A3.

[0056] The fifth circular arc A5 is a part of a circle C5, which is indicated in fig. 7 with a dashed line. The fifth circular arc A5 has a center point CP1 in common with the circle C5. A peripheral portion 46 of the heat exchanger plate 1a is provided rounded comers 48. The rounded corner 48 positioned at the left half 4 and the upper half 12 of the heat exchanger plate 1a represents a sixth circular arc A6 with a radius R6. The sixth circular arc A6 has the center point CP1 in common with the fifth circular arc A5.

[0057] According to an example in fig. 8 a first distance D1 is defined between the first point P1 and the third point P3, a second distance D2 is defined between the first point P1 and the fourth point P4, a third distance D3 is defined between the second point P2 and the fourth point P4, a fourth distance D4 is defined between the second point P2 and the fifth point P5, and a fifth distance D5 is defined between the third point P3 and the fifth point P5, wherein the second distance D2 is 115% of the first distance D1 , the third distance D3 is 112% of the first distance D1 , the fourth distance D4 is 78% of the first distance D1 , the fifth distance D2 is 91 % of the first distance D1. According to an example, the first distance D1 between the first point P1 and the third point P3 is 69,7 mm, the second distance D2 between the first point P1 and the fourth point P4 is 80,3 mm, the third distance D3 between the second point P2 and the fourth point P4 is 78 mm, the fourth distance D4 between the second point P2 and the fifth point P5 is 54,4 mm, and the fifth distance D5 between the third point P3 and the fifth point P5 is 63,7 mm.

[0058] According to an example in fig. 9 the first circular arc A1 has a first arc length L1 , the second circular arc A2 has a second arc length L2, the third circular arc A3 has a third arc length L3, the fourth circular arc A4 has a fourth arc length L4, and the fifth circular arc A5 has a fifth arc length L5, wherein the second arc length L2 is 65% of the first arc length L1 , the third arc length L3 is 153% of the first arc length L1 , the fourth arc length L4 is 83 % of the first arc length L1 and the fifth arc length L5 is 134% of the first arc length L1 . The first circular arc A1 has a first arc length L1 of 39,8 mm, the second circular arc A2 has a second arc length L2 of 26 mm, the third circular arc A3 has a third arc length L3 of 61 mm, the fourth circular arc A4 has a fourth arc length L4 of 33 mm, and the fifth circular arc A5 has a fifth arc length L5 of 53,3 mm.

[0059] Fig. 10 schematically illustrates a heat exchanger plate 1a similar to Fig. 1 including the fins 30. The fins 30 are situated in the heat exchange portion 28. In the present embodiment, a number of guiding ribs 24a extend only to a position at a distance 50 from a respective end portion of the fins 30, which distance being configured as a mixing zone 50. The mixing zone 50 will allow the fluid to mix better and achieve an even and thereby technically desired fluid distribution in the heat exchange portion 28. The mixing zone 50 should be kept small as in this area there is no mechanical support between the plates. To hold the fins 30 in place for defining the mixing zone 50, the outermost ribs 24a’ extend into the mixing zone 50 and abut against the respective end portion of the fins 30. The foregoing description of the embodiments has been furnished for illustrative and descriptive purposes. It is not intended to be exhaustive, or to limit the embodiments to the variations described. Many modifications and variations will obviously be apparent to one skilled in the art. The embodiments have been chosen and described in order to best explicate principles and practical applications, and to thereby enable one skilled in the art to understand the invention in terms of its various embodiments and with the various modifications that are applicable to its intended use. The components and features specified above may, within the framework of the disclosure, be combined between different embodiments specified.

Claims

CLAIMS1 . A plate heat exchanger (2) comprising a heat exchanger plate (1 a, 1 b) being divided into a left half (4) and a right half (6) by a longitudinal center axis (Y), which left half (4) and right half (6) are delimited by a first long side (8) and second long side (10), respectively, and wherein the heat exchanger plate (1 a, 1 b) further is divided into an upper half (12) and a lower half (14) by a transverse center axis (X), which upper half (12) and a lower half (14) are delimited by a first short side (16) and second short side (18), respectively, and wherein the heat exchanger plate (1 a, 1 b) comprises a porthole (20a) arranged within the left half (4) and the upper half (12), characterized in that the shape of the porthole (20a) is defined by a number of circular arcs (A1 , A2, A3, A4, A5), wherein individual radiuses (R1 , R2, R3, R4, R5) of the circular arcs (A1 , A2, A3, A4, A5) have a sequence of decreasing and increasing relationships in a clockwise direction of the porthole (20a) starting from the largest radius (R1 , R2, R3, R4, R5), wherein the plate (1 ) comprises a port portion (22) arranged adjacent to the porthole (20a), wherein guiding ribs (24) are arranged in the port portion (22), which guiding ribs (24) are configured to define fluid guide channels (26) between the porthole (20a) and a heat exchange portion (28) of the plate (1 a, 1 b), and wherein the fluid guide channels (26) open at the position of the third circular arc (A3), the heat exchanger (2) is a permanently bonded heat exchanger (2), wherein fins (30) are arranged in the heat exchange portion (28), which fins (30) are configured to create a number of parallel fin channels (32) for heat exchange medium (34, 35).

2. The plate heat exchanger (2) according to claim 1 , wherein the number of circular arcs (A1 , A2, A3, A4, A5) are five circular arcs (A1 , A2, A3, A4, A5): a first circular arc (A1 ) with a first radius (R1 ), a second circular arc (A2) with a second radius (R2), a third circular arc (A3) with a third radius (R3), a fourth circular arc (A4) with a fourth radius (R4) and a fifth circular arc (A5) with a fifth radius (R5) arranged in sequence in a clockwise direction of the porthole (20a).

3. The plate heat exchanger (2) according to claim 2, wherein the sequence of decreasing and increasing relationships of the individual radiuses (R1 , R2, R3, R4, R5) of the circular arcs (A1 , A2, A3, A4, A5) are: first radius (R1 ) > second radius (R2);second radius (R2) < third radius (R3); third radius (R3) > fourth radius (R4); fourth radius (R4) < fifth radius (R5).

4. The plate heat exchanger (2) according to any one of the claims 2 and 3, wherein the second radius (R2) is in the range of 17 - 23% of the first radius (R1 ), the third radius (R3) is in the range of 84 - 90% of the first radius (R1 ); the fourth radius (R4) is in the range of 28 - 34 % of the first radius (R1), and the fifth radius (R5) is in the range of 41 - 47% of the first radius (R1 ).

5. The plate heat exchanger (2) according to any one of the claims 2 and 3, wherein the second radius (R2) is 19,7% of the first radius (R1 ), the third radius (R3) is 87,5% of the first radius (R1 ); the fourth radius (R4) is 31 ,2 % of the first radius (R1 ), and the fifth radius (R5) is 43,8% of the first radius (R1 ).

6. The plate heat exchanger (2) according to any one of the claims 2 - 5, wherein the second circular arc (A2) is arranged closest to the longitudinal center axis (Y) in relation to the first circular arc (A1 ), the third circular arc (A3), the fourth circular arc (A4) and the fifth circular arc (A5).

7. The plate heat exchanger (2) according to any one of the claims 2 - 6, wherein the fourth circular arc (A4) is arranged closest to the transverse center axis (X) in relation to the first circular arc (A1 ), the second circular arc (A2), the third circular arc (A3), and the fifth circular arc (A5).

8. The plate heat exchanger (2) according to any one of the claims 2 - 7, wherein the first circular arc (A1 ) has a first arc length (L1 ), the second circular arc (A2) has a second arc length (L2), the third circular arc (A3) has a third arc length (L3), the fourth circular arc (A4) has a fourth arc length (L4), and the fifth circular arc (A5) has a fifth arc length (L5), wherein the second arc length (L2) is 65% of the first arc length (L1), the third arc length (L3) is 153% of the first arc length (L1 ), the fourth arc length (L4) is 83 % of the first arc length (L1 ) and the fifth arc length (L5) is 134% of the first arc length (L1).

9. The plate heat exchanger (2) according to any one of the claims 2 - 8, wherein the first circular arc (A1 ) is connected to the second circular arc (A2) at a firstpoint (P1 ), the second circular arc (A2) is connected to the third circular arc (A3) at a second point (P2), the third circular arc (A3) is connected to the fourth circular arc (A4) at a third point (P3), and the fourth circular arc (A4) is connected to the fifth circular arc (A5) at a fourth point (P4).

10. The plate heat exchanger (2) according to claim 9, wherein a first distance (D1 ) is defined between the first point (P1 ) and the third point (P3), a second distance (D2) is defined between the first point (P1 ) and the fourth point (P4), a third distance (D3) is defined between the second point (P2) and the fourth point (P4), a fourth distance (D4) is defined between the second point (P2) and the fifth point (P5), and a fifth distance (D5) is defined between the third point (P3) and the fifth point (P5), wherein the second distance (D2) is 115% of the first distance (D1 ), the third distance (D3) is 112% of the first distance (D1), the fourth distance (D4) is 78% of the first distance (D1 ), the fifth distance (D5) is 91 % of the first distance (D1 ).

11. The plate heat exchanger (2) according to any one of the preceding claims, wherein the transition between the circular arcs (A1 , A2, A3, A4, A5), which are adjacent to each other, are so arranged that there is a tangential constraint between the adjacent circular arcs (A1 , A2, A3, A4, A5).

12. The plate heat exchanger (2) according to any one of the preceding claims, wherein the guiding ribs (24) are straight and extend in an oblique angle relative to the longitudinal axis (Y), the guiding ribs (24) being formed as corrugations in the heat exchanger plate (1a, 1 b).

13. The plate heat exchanger (2) according to any of the preceding claims, wherein a number of the guiding ribs (24a) extend to a position at a distance from a respective end portion of the fins (30), which distance being configured as a mixing zone (50).

14. The plate heat exchanger (2) according to claim 13, wherein the outermost guiding ribs (24a’) extend into the mixing zone (50) and abut against the respective end portion of the fins (30).

15. The plate heat exchanger (2) according to one of the preceding claims, wherein the heat exchanger (2) comprising at least two opposing heat exchanger plates (1a, 1 b) with opposing guiding ribs (24) contact each other to establish the guide channels, the guiding ribs (24) of opposing heat exchanger plates forming a cross- corrugated pattern.

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