Plate heat exchanger

Abstract

The present disclosure relates to a plate heat exchanger (10) comprising a permanently joined plate (1) including a first heat transfer plate (1') and a second heat transfer plate (1''). The heat transfer pattern comprises ridges (36) and grooves (38). The ridges (36) extend along a ridge line (46), and the grooves (38) extend along a groove line (48). In a heat transfer region (34), the first heat transfer plate (1') is permanently joined to the second heat transfer plate (1'') at a plurality of joints (50) along the ridge line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1''). For each joint (50) of the plurality of joints (50), the quotient of the perimeter O of the joint (50) and the area A of the joint (50) is O / A ≧ 2.6 mm -1 is satisfied.

Description

Technical Field

[0001] The present invention relates to a plate heat exchanger.

Background Art

[0002] International Publication No. 2011 / 162659 discloses a plate heat exchanger including several heat exchanger plates arranged side by side with each other, forming first plate gaps and second plate gaps in an alternating order. All the second heat exchanger plates form primary plates, and all the second heat exchanger plates form secondary plates. Each heat exchanger plate extends in an extending plane and includes a heat transfer region and an edge region around the heat transfer region. The heat transfer region includes corrugated ridges and valleys, which each extend longitudinally. The ridges have two edge surfaces and a support surface between the edge surfaces having a first width transverse to the longitudinal direction. The valleys have two edge surfaces and a support surface between the edge surfaces having a second width transverse to the longitudinal direction. The support surface of the valleys of the primary plates is inclined with respect to the extending plane, and the support surface of the ridges of the secondary plates is inclined with respect to the extending plane.

[0003] In the plate heat exchanger of International Publication No. 2011 / 162659, the ridges and valleys of the primary plates extend intersecting the ridges and valleys of the secondary plates. Since the support surfaces of the valleys and ridges are inclined with respect to the extending plane, small-area contact points are formed at the intersections of the ridges and valleys of the primary and secondary plates.

[0004] In addition to the concept of the inclined support surfaces, International Publication No. 2011 / 162659 also discloses the common longitudinal arrangement of the ridges and valleys of adjacent plates intersecting each other. Thus, a plurality of individual contact points are formed across the heat transfer region, and the plates are permanently joined to each other, for example, by brazing with a copper or nickel-based brazing material.

[0005] U.S. Patent No. 4,915,165 discloses a plate heat exchanger, wherein the heat exchanger plates are provided by pressing in a corrugated pattern having ridges and valleys, and the ridges and valleys of adjacent plates extend parallel to each other. In each plate gap, the ridges of adjacent plates abut against each other such that the opposing valleys form parallel flow paths within the plate gap. At least some of the ridges of the heat exchanger plates are provided with recesses that form thresholds in the valleys formed on both sides of the plate by the ridges. Such thresholds are formed in the heat exchanger plates such that they provide a significantly greater flow resistance for the plate gap for one heat exchange medium compared to the plate gaps for other heat exchange media.

[0006] The ridges and valleys of each plate of the plate heat exchanger of U.S. Patent No. 4,915,165 are arranged in a main direction along the heat exchanger plate, i.e., along the longitudinal extension of the plate. U.S. Patent No. 4,915,165 mentions the possibility of permanently connecting the heat exchanger plates to each other by soldering or welding, but the present invention is described in the context of a plate heat exchanger in which gaskets are provided between adjacent heat exchanger plates of the plate heat exchanger. Accordingly, the characteristics and arrangement of the joints between adjacent heat transfer plates in embodiments of the plate heat exchanger that are soldered or welded are not described in U.S. Patent No. 4,915,165.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] It would be advantageous to achieve a plate heat exchanger having firmly joined heat transfer plates. In particular, it is desirable to provide a plate heat exchanger with a strong joint of each heat transfer surface between the heat transfer plates. To better address one or more of these concerns, a plate heat exchanger having the features defined in the independent claims is provided.

Means for Solving the Problems

[0009] According to one aspect, a plate heat exchanger is provided that includes a plate package of permanently joined heat transfer plates. Each of the first heat transfer plate and the adjacent second heat transfer plate of the plate package includes a first end, a central portion, and a second end that are continuously arranged along the longitudinal axis of the respective heat transfer plate. At least one port hole is provided at the first end, at least one port hole is provided at the second end, and the central portion includes a heat transfer region provided with a heat transfer pattern. The heat transfer pattern includes ridges and grooves, the top of the ridge extends in a first plane, the bottom of the groove extends in a second plane, the first plane and the second plane are parallel to each other, and form the outer boundary of the heat transfer pattern in a direction perpendicular to the longitudinal axis. The ridge is interrupted by an intermediate section extending at a height different from the first plane and / or the groove is interrupted by an intermediate section extending at a height different from the second plane. The ridge extends along a plurality of ridge lines, the groove extends along a plurality of groove lines, the ridge lines and the groove lines are alternately arranged and extend parallel to each other. In the heat transfer region, the first heat transfer plate is permanently joined to the second heat transfer plate at a plurality of joints along the ridge lines of the first heat transfer plate and the groove lines of the second heat transfer plate. For each joint of the plurality of joints, the quotient of the perimeter O of the joint and the area A of the joint is O / A≧2.6mm -1 is.

[0010] In the heat transfer region, the first heat transfer plate is permanently joined to the second heat transfer plate at a plurality of joints along the raised line of the first heat transfer plate and the groove line of the second heat transfer plate. Also, for each joint of the plurality of joints, the quotient of the perimeter O of the joint and the area A of the joint is O / A ≧ 2.6 mm -1 Therefore, the joints arranged along the raised line and the groove line are configured in a particularly preferred way from the viewpoint of the strength of the joints. These strong joints are provided in the heat transfer regions of the first heat transfer plate and the second heat transfer plate. Thus, a plate heat exchanger having the intended strength characteristics is achieved.

[0011] Since the plurality of joints between the first heat transfer plate and the second heat transfer plate in the heat transfer region extend along the raised line and the groove line, each individual joint of the plurality of joints has a length along the raised line and the groove line. That is, each individual joint of the plurality of joints has a length along the raised line and the groove line that is longer than the width intersecting the raised line and the groove line. For example, each individual joint of the plurality of joints may have an elliptical shape, a super-elliptical shape with a convex perimeter, or a substantially rectangular shape.

[0012] The inventor has recognized that the length of the joint between two permanently joined heat transfer plates is more important than the area of the joint. Looking at a conventional joint of a substantially circular shape between heat transfer plates subjected to a load, it was found that in the cross-section of the joint, the joint becomes longer at the periphery of the joint than at the center of the joint. Therefore, the periphery of the joint was locally subjected to a higher load at its periphery than at its center.

[0013] The inventor recognized that by providing an elongated joint, the length around the joint increases compared to a circular joint having the same area. Accordingly, the load is distributed over the long perimeter, and the load received by the long perimeter is smaller per unit length than that of a circular joint. Thus, the inventor recognized that by ensuring that the joint is long compared to its width, which can be defined by the quotient of the perimeter O of the joint and the area A of the joint, efficient joining of the heat transfer plates is achieved. For joints of relevant sizes in a plate heat exchanger of a general size, the quotient is O / A ≧ 2.6 mm -1 is satisfied.

[0014] Compared with International Publication No. 2011 / 162659, in this plate heat exchanger, a longer and thus stronger joint is provided between two adjacent heat transfer plates.

[0015] In International Publication No. 2011 / 162659, due to the intersection of the ridges and valleys, the joint formed between two adjacent plates provides only spot-shaped contact points. To increase the strength of the adhesion between two adjacent plates, the number of contact points between two adjacent plates has to be increased. Such means requires increasing the number of valleys and ridges, which reduces the distance between two adjacent plates, and thus, this significantly changes the flow characteristics of the heat transfer fluid passing through the heat exchanger.

[0016] In this specification, the plate heat exchanger may sometimes be simply referred to as a heat exchanger.

[0017] In this specification, the heat transfer plate may sometimes be referred to as a plate. In the art, the heat transfer plate may also be referred to as a heat exchanger plate or a heat exchange plate.

[0018] Each of the heat transfer plates may have a substantially rectangular shape when viewed perpendicular to the first plane and the second plane.

[0019] The main part of the heat transfer plates, such as all the heat transfer plates of the plate package, may be of the same type as the first heat transfer plate and the second heat transfer plate.

[0020] If not all the heat transfer plates are of the same type, at least the heat transfer patterns of all the heat transfer plates may be the same.

[0021] The plate heat exchanger is arranged for heat exchange between at least two fluids. The two fluids flow through both sides of each of the heat transfer plates through the plate package. The fluid flows through the gaps between the heat transfer plates.

[0022] At least one of the fluids flows into and out of the plate package through a port hole flow path formed by at least one port hole at each of the first end and the second end and the corresponding port holes of the other heat transfer plates. Further fluids may also flow into and out of the plate package through further port hole flow paths formed by the port holes of the heat transfer plates. Alternatively, the alternating gaps between the plates are opened from the side of the plate package so that one of the fluids can flow through the plate package in a direction intersecting the longitudinal axis.

[0023] Together with the port holes of the adjacent heat transfer plates, at least one port hole at the first end of the first heat transfer plate and the second heat transfer plate forms a port hole flow path penetrating the plate package perpendicular to the longitudinal axis. Similarly, together with the port holes of the adjacent heat transfer plates, at least one port hole at the second end of the first heat transfer plate and the second heat transfer plate forms a port hole flow path penetrating the plate package perpendicular to the longitudinal axis.

[0024] The gap formed between the first heat transfer plate and the second heat transfer plate within the plate package may be arranged in fluid communication with the two port hole flow paths described above. Alternatively, the gap between the first heat transfer plate and the second heat transfer plate may be arranged in fluid communication with two additional port hole flow paths. The additional port hole flow paths are formed by additional port holes at the first and second ends of the first heat transfer plate and the second heat transfer plate, and the port holes of the adjacent heat transfer plates within the plate package.

[0025] A further alternative may be to open the gap between the first heat transfer plate and the second heat transfer plate from the side of the plate. In the latter case, the port holes at the first and second ends of the first heat transfer plate and the second heat transfer plate form a port hole flow path together with the adjacent heat transfer plates. The port hole flow path thus formed is in fluid communication with the gap formed between the first heat transfer plate, the second heat transfer plate, and the adjacent heat transfer plates.

[0026] During the use of the plate heat exchanger, heat transfer between two fluids or two media such as heat transfer fluids mainly occurs through the heat transfer regions of the respective heat transfer plates. The number of heat transfer plates and the size and shape of the heat transfer regions of each plate give a specific heat exchange capacity to a specific flow rate of fluid flowing through the heat exchanger.

[0027] The general shape of the heat transfer region of the heat transfer plate is defined by the raised portions and the groove portions as described above. Within this general shape, various modifications are expected to adapt a specific heat exchanger to a specific heat exchange capacity, such as changing the distance between the raised portion and the groove portion, changing the distance between the first plane and the second plane, and changing the length of the intermediate section.

[0028] The raised portion of the first heat transfer plate and the groove portion of the second heat transfer plate are in contact with each other along the raised line of the first heat transfer plate and the groove line of the second heat transfer plate in the heat transfer region. In a corresponding manner, the raised portions and groove portions of further heat transfer plates of the plate package are in contact with each other along the raised line and the groove line.

[0029] By the raised portion and the groove portion of adjacent heat transfer plates being in contact with each other along the raised line and the groove line, a flow path is formed in the gap formed between the plates. In other words, due to the contact of the raised portion and the groove portion of adjacent heat transfer plates along the raised line and the groove line in the heat transfer region, the gap between the first plate and the second plate is formed by flow paths extending in parallel.

[0030] In the gap between the first heat transfer plate and the second heat transfer plate, the middle section of the raised portion and the middle section of the groove portion enable the fluid passing through the gap to flow between the flow paths formed by the contact of the raised portion and the groove portion of the first heat transfer plate and the second heat transfer plate. For example, this can contribute to the fluid passing through the entire heat transfer region and / or adapting the flow resistance within the gap.

[0031] The raised line may be a line along which the raised portion of the heat transfer plate extends. The raised line may be, for example, straight or may have a serrated shape such as a zigzag shape. The raised line may be interrupted by an intermediate section. The raised line extends parallel to the heat transfer region of the heat transfer plate. Similarly, the groove line may be a line along which the groove portion of the heat transfer plate extends. The groove line may be, for example, straight or may have a serrated shape such as a zigzag shape. The groove line may be interrupted by an intermediate section. The groove line extends parallel to the heat transfer region of the heat transfer plate.

[0032] In the heat transfer regions of adjacent heat transfer plates, the ridges of one plate abut against the grooves of the adjacent plate along their respective ridge lines and groove lines. That is, in the heat transfer regions, the ridges and grooves of adjacent plates do not cross each other.

[0033] The ridges and grooves of the heat transfer plates, together with their respective intermediate sections of the ridges and grooves, form a heat transfer pattern. The heat transfer pattern can provide a desired flow resistance to the heat transfer fluid and / or promote turbulence of the heat transfer fluid, and thus can achieve a specific heat transfer capacity of the plate heat exchanger associated with the use of the plate heat exchanger.

[0034] The joints may be formed by a joining method in which the plates are subjected to heat lower than the melting point of the heat transfer plates. Such joining methods may be, for example, brazing with a brazing material added in the form of a foil, paste, or powder containing copper or nickel, or joining using the material of the heat transfer plates with a drop melting composition applied to the heat transfer plates before heating, as described, for example, in WO 2013 / 144211.

[0035] According to an embodiment, the first heat transfer plate and the second heat transfer plate may be of the same type. In the plate package, the second heat transfer plate may be rotated 180 degrees parallel to the first plane and the second plane with respect to the first heat transfer plate. In this way, at least a part of the plate package may include only one type of heat transfer plate. This facilitates the manufacture of the plates included in the plate package.

[0036] The remaining heat transfer plates of the plate package may be arranged adjacent to each other in the same manner, that is, rotated 180 degrees parallel to the first plane and the second plane with respect to the adjacent heat transfer plates.

[0037] According to an embodiment, a part of each intermediate section of the raised portion extends at the height of the second plane, and / or a part of each intermediate section of the groove portion extends at the height of the first plane. In this way, an opening having a height of the distance between the first plane and the second plane may be formed by the intermediate section. The opening fluidly connects adjacent flow paths formed by the abutting raised portion and groove portion within the gap between two adjacent heat transfer plates, such as between the first heat transfer plate and the second heat transfer plate.

[0038] According to an embodiment, the top or the raised portion may be wider than the bottom of the groove portion in the second plane in the first plane, or the bottom of the groove portion may be wider than the top of the raised portion in the first plane in the second plane. In this way, a narrow width of the joint of the plurality of joints can be achieved. Furthermore, in this way, it can be ensured that the raised portion of one plate abuts against the groove portion of the adjacent plate. Therefore, even if there is a certain degree of inaccuracy in the lateral positioning of the raised portion and the groove portion of the heat transfer pattern of the adjacent plates, the abutment can be achieved.

[0039] According to an embodiment, at the first end, the first heat transfer plate and the second heat transfer plate may be joined by a first series of joints arranged at least partially circumferentially around at least one port hole at the first end. At the second end, the first heat transfer plate and the second heat transfer plate may be joined by a second series of joints arranged at least partially circumferentially around at least one port hole at the second end. The heat transfer pattern in the central portion may be arranged directly adjacent to and extend between the first series of joints and the second series of joints. In this way, most of the heat transfer plate can be formed by the central portion, and thus most of the heat transfer plate can form a heat transfer region. Therefore, the heat transfer plate can be utilized for optimal heat transfer.

[0040] According to an embodiment, the raised portion lines and the groove lines may extend along a straight line, and the raised portion lines and the groove lines may extend at one or more angles within a range of 0 to 90 degrees with respect to the longitudinal axis. In this way, the raised portions and the groove portions may extend at a smaller or lesser angle with respect to the overall direction of at least one of the heat transfer fluids intended to flow through the plate heat exchanger substantially parallel to the longitudinal axis. Therefore, the flow resistance of at least one heat transfer fluid can be adapted, inter alia, by the angles of the raised portion lines and the groove lines with respect to the longitudinal axis.

[0041] Further features and advantages of the present invention will become apparent when considering the appended claims and the following detailed description.

[0042] Various aspects and / or embodiments of the present invention, including its specific features and advantages, will be readily understood from the exemplary embodiments described in the following detailed description and the accompanying drawings.

Brief Description of the Drawings

[0043]

Figure 1a

Figure 1b

Figure 2a

Figure 2b

Figure 3a

Figure 3b

Figure 4

Figure 5a

Figure 5b

Figure 6

Mode for Carrying Out the Invention

[0044] Next, aspects and / or embodiments of the present invention are described more fully. The same numbers refer to the same elements throughout. Well-known functions or structures are not necessarily described in detail for the sake of brevity and / or clarity.

[0045] Figures 1a and 1b show a plate heat exchanger 10 according to an embodiment.

[0046] The plate heat exchanger 10 includes a plurality of heat transfer plates 1 according to any of the embodiments described herein, a first end plate 2 provided beside one of the outermost heat transfer plates 1, and a second end plate 3 provided beside the outermost heat transfer plate 1 on the opposite side. Since the second end plate 3 is arranged within the flange 7 of the associated outermost heat transfer plate 1, it is not visible in the view of Figure 1a. Therefore, in Figure 1a, the second end plate 3 is shown by a dashed line. The longitudinal axis LA extends along the length of the plate 1.

[0047] The heat transfer plates 1 are manufactured by sheet metal forming and are arranged side by side with each other. The first end plate 2, the second end plate 3, and the heat transfer plates 1 are permanently joined to each other to form a plate package 4. Each heat transfer plate 1 includes a flange 7 extending around the heat transfer plate 1. The flanges 7 of adjacent plates 1 may overlap and are permanently joined to each other.

[0048] Within the plate package 4, adjacent heat transfer plates 1 define therebetween a first plate gap for a first medium and a second plate gap for a second medium (see, for example, FIGS. 3a and 3b). The first medium and the second medium may be any suitable fluid through which heat is transferred during use of the plate heat exchanger 10.

[0049] The plate heat exchanger 10 of the disclosed embodiment has four port hole flow paths S1, S2, S3, and S4 formed by the port holes of the individual plates 1. The port hole flow path S1 is connected to the connecting pipe 11 and communicates with the first plate gap. The port hole flow path S2 is connected to the connecting pipe 12 and communicates with the first plate gap. The port hole flow path S3 is connected to the connecting pipe 13 and communicates with the second plate gap, and the port hole flow path S4 is connected to the connecting pipe 14 and communicates with the second plate gap.

[0050] It should be noted that the plate heat exchanger may have a different number of port hole flow paths provided by a corresponding number of port holes in the heat transfer plates 1 other than those disclosed, such as 2, 3, 5, 6, 7, or 8 port hole flow paths.

[0051] The connecting pipes in fluid communication with the port hole flow paths may be provided to extend from the first end plate 2 and / or from the second end plate 3 as disclosed.

[0052] FIGS. 2a and 2b show a heat transfer plate 1 according to an embodiment. FIG. 2a shows a top view of the entire plate 1, and FIG. 2b shows a top view of a part of the plate 1. For simplicity, in FIGS. 2a and 2b, the circumferential flange portions of the plate 1 are omitted.

[0053] The plate 1 is of the same type as the plate 1 of the plate heat exchanger 10 shown in FIGS. 1a and 1b. Thus, the plate heat exchanger can be assembled by permanently joining the plurality of plates 1 shown in FIGS. 2a and 2b.

[0054] The heat transfer plate 1 has a rectangular shape with two long side edges 16 and two short side edges 18. The longitudinal axis LA extends transversely to the short side edges 18, parallel to the long side edges 16.

[0055] In a plate heat exchanger, the heat transfer plate 1 is permanently joined to adjacent heat transfer plates of the same or a similar type in order to form a plate package.

[0056] The first heat transfer plate 1 and the adjacent second heat transfer plate 1 of the plate package may be of the same type. In the plate package, the second heat transfer plate may be rotated 180 degrees with respect to the first heat transfer plate in a plane including the longitudinal axis LA as well as the long side edges 16 and the two short side edges 18. In this way, the first plate 1, the second plate 1 of the same type, and further heat transfer plates 1 can be utilized to form at least a major part of the plate package.

[0057] Each of the heat transfer plates 1 of the plate package and further heat transfer plates comprises a first end 20, a central part 22, and a second end 24 that are arranged successively along the longitudinal axis LA of the respective heat transfer plate 1. At least one port hole 26, 32 is provided in the first end 20, and at least one port hole 28, 30 is provided in the second end 24.

[0058] In these embodiments, two port holes 26 - 32 are provided in each of the first end 20 and the second end 24.

[0059] The central part 22 comprises a heat transfer region 34 provided with a heat transfer pattern. The heat transfer region 34 forms a region where the major part of the heat transfer between the first medium and the second medium on both sides of the plate 1 occurs during the use of the plate heat exchanger.

[0060] At each of the first end 20 and the second end 24, each port hole 26 - 32 is surrounded by a port hole region 35 as illustrated at the first end 20 of FIG. 2b. In a known method, the port hole regions 35 are shaped such that along each port hole flow path within the heat exchanger, the heat transfer plates 1 alternately seal against each other to define flow-through paths that enter and exit each gap between the plates 1.

[0061] More specifically, in each port hole region 35 of the first end 20 and the second end 24, the heat transfer plates 1 are provided with unevenness configured to abut against corresponding unevenness of adjacent heat transfer plates 1. The port holes within each port hole region 35 of each heat transfer plate 1 may be cut out in different diameters or in different shapes along each port hole flow path to alternately open between the plates 1 and provide sealed gaps.

[0062] A series of joints are arranged at positions where such unevenness abuts against each other. The joints are arranged at least partially circumferentially around the port holes 26 - 32 of the ends 20, 24.

[0063] Here too, as mentioned by way of example, in a known method, the heat transfer plates 1 may be of the same type. Within the plate package 4, the individual heat transfer plates 1 are stacked on respective second heat transfer plates 1 rotated 180 degrees about an axis perpendicular to the plane including the long edge portion 16 and the short edge portion 18 of the plate 1. Thus, abutment and sealing against each other in the port hole regions 35 to define flow-through paths that enter and exit each gap between the plates 1 can be achieved. Alternatively, other known methods of achieving alternating sealing and flow-through may be used, for example, by providing port hole regions of corresponding shapes for more than one type of heat transfer plate 1.

[0064] The heat transfer region 34 of the central portion 22 has a heat transfer pattern of alternately arranged ridges 36 and grooves 38 that extend parallel to each other. The top of the ridge 36 extends in a first plane, and the bottom of the groove 38 extends in a second plane.

[0065] The ridge 36 is interrupted by an intermediate section 44 that extends at a height different from the first plane. Additionally or alternatively, the groove 38 is interrupted by a corresponding intermediate section (not shown) that extends at a height different from the second plane. More specifically, the intermediate section 44 forms a portion of the heat transfer pattern that interrupts the ridge 36 and / or the groove 38, respectively.

[0066] The ridge 36 extends along a plurality of ridge lines 46 (shown in dashed double lines), and the groove 38 extends along a plurality of groove lines 48 (shown in dotted lines). The ridge lines 46 and the groove lines 48 are alternately arranged in the heat transfer region 34 and extend parallel to each other.

[0067] Further reference is made below with reference to FIGS. 3a and 3b regarding the arrangement of the ridges 36 and grooves 38 of two adjacent plates 1, and the arrangement of the top of the ridge 36 extending in the first plane and the bottom of the groove 38 extending in the second plane.

[0068] According to some embodiments, such as the illustrated embodiment, as clearly shown in FIG. 2b, the heat transfer pattern of the central portion 22 is arranged directly adjacent to the port hole region 35, that is, the heat transfer pattern extends to the unevenness of the port hole region 35 at each of the first end 20 and the second end 24 of the heat transfer plate 1. Thus, most of the heat transfer plate 1 can be formed by the heat transfer region 34 including the heat transfer pattern.

[0069] More specifically, according to the embodiment, at the first end 20, the first heat transfer plate 1 and the second heat transfer plate 1 may be joined by a first series of joints disposed at least partially circumferentially around at least one port hole 26, 32 of the first end 20. At the second end 24, the first heat transfer plate 1 and the second heat transfer plate 1 may be joined by a second series of joints disposed at least partially circumferentially around at least one port hole 28, 30 of the second end 24. The heat transfer pattern of the central portion 22 is disposed directly adjacent to and may extend between a first series of joints and a second series of joints disposed at least partially circumferentially around at least one of the port holes 26-32 of the first end 20 and the second end 24, respectively.

[0070] In these embodiments, the rib lines 46 and the groove lines 48 extend along a straight line. The rib lines 46 and the groove lines 48 extend at one or more angles α within the range of 0 to 90 degrees with respect to the longitudinal axis LA. In FIG. 2b, the angle α is shown to be about 45 degrees.

[0071] According to some embodiments, the rib lines 46 and the groove lines 48 extend along a straight line, and the rib lines 46 and the groove lines 48 extend at one or more angles α within the range of >0 to 80 degrees with respect to the longitudinal axis LA.

[0072] The size of the angle α affects the flow resistance of at least one heat transfer fluid flowing through the gap between the plates 1. The angle α can be selected to provide a desired flow resistance to the plate heat exchanger in which the plates 1 form a plate package.

[0073] FIGS. 3a and 3b show cross-sectional perspective views of three heat transfer plates 1 of a plate package 4 of a plate heat exchanger according to an embodiment. The cross-section extends along the edge of the plate package 4, and in FIGS. 3a and 3b, the gap 6 between the plates 1 is shown. FIG. 3b shows a more enlarged view of the cross-section of FIG. 3a.

[0074] The plate 1 shown in FIGS. 3a and 3b may be of the same type as the plate 1 shown in FIGS. 2a and 2b. The plate heat exchanger including the plate 1 in FIGS. 3a and 3b may be of the same type as the plate heat exchanger 10 described above with reference to FIG. 1. Therefore, FIGS. 1 to 2b are also referred to below.

[0075] The plate package 4 of the plate heat exchanger comprises a plurality of permanently joined heat transfer plates 1.

[0076] Each of the first heat transfer plate 1' and the adjacent second heat transfer plate 1'' of the plate package 4 comprises a first end 20, a central portion 22, and a second end 24 as described above with reference to FIGS. 2a and 2b. In FIGS. 3a and 3b, the second plate 1'' is stacked on the first plate 1'.

[0077] Here too, at least one port hole is provided at the first end, at least one port hole is provided at the second end (not shown in FIG. 3a), and the central portion comprises a heat transfer region 34 provided with a heat transfer pattern.

[0078] Here too, the heat transfer pattern comprises a raised portion 36 and a groove portion 38. The top of the raised portion 36 extends within a first plane 40 (shown by a dashed line), and the bottom of the groove portion 38 extends within a second plane 42 (shown by a dashed-dotted line). The first plane 40 and the second plane 42 extend parallel to each other and form the outer boundary of the heat transfer pattern in a direction perpendicular to the longitudinal axis LA.

[0079] In the heat transfer region 34, the first heat transfer plate 1' is permanently joined to the second heat transfer plate 1'' at a plurality of joints along the raised portions 36 of the first heat transfer plate 1' and the groove portions 38 of the second heat transfer plate 1''. Similarly, throughout the plate package 4, further heat transfer plates are joined along the raised and groove portions of adjacent heat transfer plates 1. Thus, within the plate package 4, adjacent heat transfer plates 1 define between them a first plate gap 6 for a first medium and a second plate gap 6' for a second medium.

[0080] The gaps 6, 6' formed in this way are constituted by flow paths 39 extending between a first plane 40 and a second plane 42, and the flow paths 39 are formed between the joined raised portions 36 and groove portions 38 of adjacent heat transfer plates 1.

[0081] The raised portion 36 is interrupted by an intermediate section 44 extending at a height different from that of the first plane 40, and / or the groove portion 38 is interrupted by an intermediate section extending at a height different from that of the second plane 42.

[0082] Due to the intermediate section 44, during use of the heat exchanger, the fluid passing along the gaps 6, 6' between the two plates 1 can flow between the flow paths 39.

[0083] A part of each intermediate section 44 of the raised portion 36 may extend at the height of the second plane 42, and / or a part of each intermediate section of the groove portion 38 may extend at the height of the first plane 40.

[0084] The raised portion 36 extends along a plurality of raised portion lines 46 (shown by a two-dot chain line in Fig. 3a), and the groove portion 38 extends along a plurality of groove lines 48 (shown by a dotted line in Fig. 3a). The raised portion lines 46 and the groove lines 48 are arranged alternately and extend in parallel.

[0085] Correspondingly, the raised portions and groove portions of the remaining heat transfer plates 1 of the plate package 4 also extend along the raised portion lines and groove lines.

[0086] In FIGS. 3a and 3b, the raised portion 36 and the groove portion 38, the first plane 40 and the second plane 42, and the raised portion line 46 and the groove line 48 are shown with respect to the second heat transfer plate 1''. Each of the first heat transfer plate 1' and the remaining heat transfer plates 1 of the plate package 4 has corresponding raised portions and groove portions, a first plane and a second plane, and a raised portion line and a groove line.

[0087] In the heat transfer region 34, the first heat transfer plate 1' is permanently joined to the second heat transfer plate 1'' at a plurality of joints along the raised portion line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1''. That is, the raised portion 36 of the first plate 1' is joined to the groove portion 38 of the second plate 1''.

[0088] For each joint of the plurality of joints, the quotient of the perimeter O of the joint and the area A of the joint is O / A ≧ 2.6 mm -1 is.

[0089] As initially explained, joints having a quotient O / A ≧ 2.6 mm -1 have been found to provide a strong joint between the heat transfer plates 1 in the heat transfer region 34 of the heat transfer plate 1, and thus a strong adhesion of the plate package 4.

[0090] Since each of the joints of the plurality of joints extends along the raised portion line 46 and the groove line 48, each individual joint of the plurality of joints has a length along the raised portion line 46 and the groove line 48. Also, each individual joint of the plurality of joints has a length along the raised portion line and the groove line that is longer than the width intersecting the raised portion line and the groove line. See further below with reference to FIG. 4.

[0091] According to an embodiment, the heat transfer plate 1 that is permanently joined may be joined by a joint containing at least 50 wt% of a metal of the same type as the metal of the heat transfer plate 1. In this way, the joint may be formed by a method of joining the heat transfer plate 1 using a fluxing composition that lowers the melting temperature of the metal of the heat transfer plate.

[0092] Merchant O / A ≧ 2.6 mm -1 The joint defined in this specification having [the above condition] is well suited to provide strong adhesion between the heat transfer plates 1 by a joint containing at least 50 wt% of a metal of the same type as the metal of the heat transfer plate 1.

[0093] The joint may contain at least 85 wt% of a metal of the same type as the metal of the heat transfer plate 1, for example, up to 100 wt% of a metal of the same type as the metal of the heat transfer plate 1.

[0094] For example, as described in International Publication No. 2013 / 144211, the heat transfer plate 1 may be joined using a method of joining a first metal heat transfer plate 1' and a second metal heat transfer plate 1''. The metal has a solidus temperature exceeding 1100°C. This method applying a fluxing composition to a surface portion of the first heat transfer plate 1', the fluxing composition containing boron B, or a combination of boron B and silicon Si, bringing the second heat transfer plate 1'' into contact with the fluxing composition at a contact point on the surface and includes.

[0095] The first heat transfer plate 1' and the second heat transfer plate 1'' are heated to a suitable temperature lower than the solidus temperature together with other similarly prepared plates of the plate heat exchanger, and this suitable temperature melts at least the metal of the first heat transfer plate 1' at the surface portion where the fluxing composition is applied. When the plate is cooled, the molten metal solidifies and permanently joins the heat transfer plate 1.

[0096] According to the embodiment, in the heat transfer region 34, the first heat transfer plate 1' can be permanently joined to the second heat transfer plate 1'' only along the raised line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1''. In this way, in the heat transfer region 34 of each of the first heat transfer plate 1' and the second heat transfer plate 1'', no other joints may be provided.

[0097] The upside-down FIGS. 3a and 3b show an embodiment of the plate package 4 in which the raised portion 36 forms a groove portion, and thus the groove portion 38 forms a raised portion. Such an embodiment includes a groove portion interrupted by an intermediate section 44 similar to the intermediate section 44 of the raised portion 36 described above.

[0098] FIG. 4 schematically shows the cross-sectional shape of one joint 50 among a plurality of joints along the raised line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1'' as described above with reference to FIGS. 3a and 3b. Therefore, FIGS. 3a and 3b are also referred to below.

[0099] The cross-section of the joint 50 shown in FIG. 4 is seen in a plane parallel to one of the first plane 40 and the second plane 42.

[0100] According to the embodiment, each joint 50 of the plurality of joints has a length L along the raised line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1'', and this length L is longer than the width W of each joint 50 that intersects the raised line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1''. In this way, the quotient O / A ≧ 2.6 mm -1 can be achieved in the joint 50 having an appropriate shape used in an industrially manufactured plate heat exchanger.

[0101] Such shapes may include rectangular, substantially rectangular, elliptical (non-circular), and super-elliptical shapes with a convex perimeter.

[0102] According to the embodiment, each joint of the plurality of joints may have a width W that intersects the raised portion line 46 of the first heat transfer plate 1' and the groove line 48 of the second heat transfer plate 1'', and this width W is within the range of 0.4 ≦ W ≦ 0.8 mm. In this way, the quotient O / A ≧ 2.6 mm -1 can be achieved in the joint 50 that is appropriately formed so as to be used in an industrially manufactured plate heat exchanger, and the heat characteristics of such a plate heat exchanger are achieved for efficient heat transfer between two heat transfer fluids.

[0103] In the illustrated embodiment, the joint 50 has a rectangular cross-section with rounded corners, that is, the cross-section of the joint 50 is substantially rectangular and can approximate a rectangle having a length L along the associated raised portion 36 and the abutting groove portion 38 and a width W across the raised portion 36 and the groove portion 38.

[0104] According to these embodiments, the perimeter O is calculated, O = 2×L + 2×W, the area A is calculated, A = L×W.

[0105] Within the size of the joint associated with the heat exchanger having the permanently joined heat transfer plate 1, in order to provide a strong joint, the quotient O / A ≧ 2.6 mm -1 is set.

[0106] For example, the quotient O / A may be in the range of 2.6 mm -1 ≦ O / A ≦ 5.4 mm -1 with respect to the size of the joint 50 within a length L in the range of 5 to 20 mm and a width W in the range of 0.4 to 0.8 mm. Speaking purely as four examples, the joint 50 may have the following dimensions that achieve the following quotients. L = 5 mm, W = 0.4 mm, and O / A = 5.4 mm -1 , L = 10 mm, W = 0.5 mm, and O / A = 4.2 mm -1 , L = 10 mm, W = 0.8 mm, and O / A = 2.7 mm -1 , L = 20 mm, W = 0.8 mm, and O / A = 2.6 mm -1 。

[0107] In comparison, a typical size circular joint of a prior art plate heat exchanger having a diameter of 2.5 mm achieves a commercial O / A = 1.6 mm -1 and a joint having a diameter of 5 mm achieves a commercial O / A = 0.8 mm -1 is achieved.

[0108] For a circular joint to have a commercial O / A ≥ 2.6 mm -1 it should be noted that the joint must have a diameter smaller than 0.65 mm, which is not achievable with a normally sized plate heat exchanger.

[0109] Instead of the rectangular or substantially rectangular shape of joint 50 shown in FIG. 4, for example, an elliptical shape (non - circular), or a super - elliptical shape having a convex perimeter with a length L along the raised line 46 and groove line 48 that is longer than the width W intersecting the raised line 46 and groove line 48 may be utilized.

[0110] Also, in such an embodiment of the joint, a commercial O / A ≥ 2.6 mm -1 achieves a strong joint for a plate heat exchanger of the relevant size.

[0111] FIG. 5a shows a top view of the heat transfer plate 1 according to an embodiment, and FIG. 5b shows a cross - sectional perspective view of the first heat transfer plate 1' and the second heat transfer plate 1'' of the plate package of the plate heat exchanger according to the embodiment. The cross - section extends along the edge of the plate package such that the gap 6 between the plates 1 is shown. These embodiments are very similar to the embodiments of FIGS. 1 - 4. Therefore, in the following, mainly the differences will be described.

[0112] Here too, each of the heat transfer plates 1, 1', 1'' has a heat transfer pattern with raised portions 36 and groove portions 38. The top of the raised portion 36 extends in a first plane, and the bottom of the groove portion 38 extends in a second plane. The raised portion 36 extends along a plurality of raised portion lines 46, and the groove portion 38 extends along a plurality of groove lines 48. The raised portion lines 46 and the groove lines 48 are alternately arranged and extend parallel to each other.

[0113] According to these embodiments, the raised portion lines 46 and the groove lines 48 extend along zigzag lines.

[0114] The zigzag lines 46, 48 may meander parallel to the longitudinal axis LA, as shown in FIG. 4a. Alternatively, the zigzag lines 46, 48 may intersect the longitudinal axis LA.

[0115] Here too, the raised portion 36 is interrupted by an intermediate section 44 that extends at a height different from the first plane. Additionally or alternatively, the groove portion 38 is interrupted by a corresponding intermediate section (not shown) that extends at a height different from the second plane.

[0116] According to these embodiments, the intermediate section 44 of the raised portion 36 and / or the intermediate section of the groove portion 38 is disposed at a portion of the zigzag line where the zigzag line changes direction.

[0117] FIG. 6 shows a cross-section of a first heat transfer plate 1' and a second heat transfer plate 1'' according to an embodiment. The heat transfer plates 1', 1'' may be heat transfer plates of a plate package included in any of the plate heat exchangers described above with reference to FIGS. 1 to 5b. Accordingly, FIGS. 1 to 5b are also referred to below.

[0118] Here too, each of the first heat transfer plate 1' and the second heat transfer plate 1'' has a heat transfer pattern with raised portions 36 and groove portions 38. The top of the raised portion 36 extends in a first plane 40, and the bottom of the groove portion 38 extends in a second plane 42.

[0119] According to these embodiments, the bottom of the groove portion 38 is wider than the top of the raised portion 36 in the first plane 40 in the second plane 42.

[0120] According to an alternative embodiment, as can be shown by inverting FIG. 6 upside down, the top of the raised portion may be wider than the bottom of the groove portion in the second plane in the first plane.

[0121] In these embodiments, the wide bottom or wide top can ensure that the raised portion 36 of the first plate 1' abuts against the groove portion 48 of the second plate 1'', and thus it can be ensured that the joint 50 between the raised portion 36 and the groove portion 38 is provided throughout the plate package. Also, the smaller top or smaller bottom can ensure that the joint 50 has a narrow width W.

[0122] The above are examples of various exemplary embodiments, and it should be understood that the present invention is defined only by the appended claims. Those skilled in the art will understand that the exemplary embodiments may be modified without departing from the scope of the present invention defined by the appended claims, and different features of the exemplary embodiments may be combined to form embodiments other than those described herein.

Explanation of Reference Numerals

[0123] 1 Heat transfer plate 1' First heat transfer plate 1'' Second heat transfer plate 2 First end plate 3 Second end plate 4 Plate package 6 First plate gap 6' Second plate gap 7 Flange 10 Plate heat exchanger 11 Connecting pipe 12 Connecting pipe 13 Connecting pipe 14 Connecting pipe 16 Long side edge 18 Short side edge 20 First end 22 Central part 24 Second end 26 Port hole 28 Port hole 30 Port hole 32 Port hole 34 Heat transfer region 35 Port hole region 36 Protrusion 38 Groove part 39 Flow path 40 First plane 42 Second plane 44 Intermediate section 46 Protrusion line 48 Groove line 50 Joint part L Length LA Longitudinal axis S1 Port hole flow path S2 Port hole flow path S3 Port hole flow path S4 Port hole flow path W Width α Angle

Claims

1. A plate heat exchanger (10) comprising a plate package (4) of permanently joined heat transfer plates (1), Each of the first heat transfer plate (1') and the adjacent second heat transfer plate (1'') of the plate package (4) comprises a first end (20), a central portion (22), and a second end (24) arranged continuously along the longitudinal axis (LA) of each heat transfer plate (1), wherein the first end (20) is provided with at least one port hole (26, 32), the second end (24) is provided with at least one port hole (28, 30), and the central portion (22) comprises a heat transfer region (34) provided with a heat transfer pattern. The heat transfer pattern comprises a plurality of raised portions (36) and a plurality of groove portions (38), the tops of the raised portions (36) extending into a first plane (40), the bottoms of the groove portions (38) extending into a second plane (42), the first plane (40) and the second plane (42) being parallel to each other and forming the outer boundary of the heat transfer pattern in a direction perpendicular to the longitudinal axis (LA). The raised portion (36) is interrupted by an intermediate section (44) extending at a different height from the first plane (40), and / or the groove (38) is interrupted by an intermediate section extending at a different height from the second plane (42), In a plate heat exchanger (10), the raised portion (36) extends along a plurality of raised portion lines (46), and the groove portion (38) extends along a plurality of groove lines (48), and the raised portion lines (46) and the groove lines (48) are arranged alternately and extend in parallel. In the heat transfer region (34), the first heat transfer plate (1') is permanently joined to the second heat transfer plate (1'') by a plurality of joints (50) along the raised line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1''), With respect to each of the plurality of joints (50), the quotient between the outer circumference O of the joint (50) and the area A of the joint (50) is O / A ≥ 2.6 mm. －１ A plate heat exchanger (10) characterized by the following:

2. The plate heat exchanger (10) according to claim 1, wherein each of the plurality of joints (50) has a length L along the raised line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1''), and the length L is longer than the width W of each joint (50) that intersects the raised line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1'').

3. Each of the plurality of joints (50) has a width W that intersects the raised line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1''), and the width W is in the range of 0.4 ≤ W ≤ 0.8 mm, as described in claim 1 or 2, for the plate heat exchanger (10).

4. In the heat transfer region (34), the first heat transfer plate (1') is permanently joined to the second heat transfer plate (1'') only along the raised line (46) of the first heat transfer plate (1') and the groove line (48) of the second heat transfer plate (1''), according to any one of claims 1 to 3.

5. The plate heat exchanger (10) according to any one of claims 1 to 4, wherein the first heat transfer plate (1') and the second heat transfer plate (1'') are of the same type, and in the plate package (4), the second heat transfer plate (1'') is rotated 180 degrees relative to the first heat transfer plate (1') parallel to the first plane and the second plane.

6. A plate heat exchanger (10) according to any one of claims 1 to 5, wherein a portion of each intermediate section (44) of the raised portion (36) extends to the height of the second plane (42), and / or a portion of each intermediate section of the groove (38) extends to the height of the first plane (40).

7. The plate heat exchanger (10) according to any one of claims 1 to 6, wherein the top of the raised portion (36) is wider in the first plane (40) than the bottom of the groove portion (38) in the second plane (42), or the bottom of the groove portion (38) is wider in the second plane (42) than the top of the raised portion (36) in the first plane (40).

8. At the first end (20), the first heat transfer plate (1') and the second heat transfer plate (1'') are joined by a first series of joints at least partially circumferentially arranged around the at least one port hole (26, 32) of the first end (20); at the second end (24), the first heat transfer plate (1') and the second heat transfer plate (1'') are joined by a second series of joints at least partially circumferentially arranged around the at least one port hole (28, 30) of the second end (42); and the heat transfer pattern of the central portion (22) is positioned directly adjacent to the first series of joints and the second series of joints and extends between the first series of joints and the second series of joints, according to any one of claims 1 to 7.

9. The plate heat exchanger (10) according to any one of claims 1 to 8, wherein the raised portion line (46) and the groove line (48) extend along a straight line, and the raised portion line (46) and the groove line (48) extend at one or more angles (α) in the range of 0 to 90 degrees with respect to the longitudinal axis (LA).

10. The plate heat exchanger (10) according to any one of claims 1 to 8, wherein the raised line (46) and the groove line (48) extend along a zigzag line.

11. The plate heat exchanger (10) according to claim 10, wherein the intermediate section (44) of the raised portion (36) and / or the intermediate section of the groove portion (38) are located in the portion of the zigzag line where the zigzag line changes direction.

12. The plate heat exchanger (10) according to any one of claims 1 to 11, wherein the permanently joined heat transfer plate (1) is joined by the joint (50) which contains at least 50 wt% of the same type of metal as the heat transfer plate (1).

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