Heat transfer plate, cassette and heat exchanger
By designing an upper transition area and a transition corrugated pattern on the heat transfer plate, the problem of uneven flow distribution is solved, the flow resistance is optimized, and the heat transfer capacity and flow efficiency of the heat transfer plate assembly are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ALFA LAVAL CORP AB
- Filing Date
- 2024-12-06
- Publication Date
- 2026-07-14
AI Technical Summary
The existing heat transfer plate has uneven flow distribution in the transition zone, which leads to a decrease in heat transfer capacity, and the flow velocity is inconsistent in different flow paths, affecting the heat transfer effect.
Design a heat transfer plate that includes an upper transition region with a transition corrugation pattern and distribution that differs from the heat transfer corrugation pattern. The bottom pitch is constant, and the maximum rear cross-section varies between different pairs to optimize flow resistance and ensure uniform fluid distribution.
By optimizing the flow resistance, a uniform fluid distribution within the heat transfer plate assembly was achieved, thereby improving heat transfer capacity and flow efficiency.
Smart Images
Figure CN122396895A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to heat transfer plates, boxes comprising two such heat transfer plates, and heat exchangers comprising multiple such boxes. Background Technology
[0002] A plate heat exchanger (PHE) typically comprises two end plates, between which multiple heat transfer plates are arranged in alignment (i.e., in a stack or group). The heat transfer plates of a PHE can be stacked in different ways. In some PHEs, the heat transfer plates are stacked such that the front and rear sides of one heat transfer plate face the rear and front sides of the other heat transfer plates, respectively, and every other heat transfer plate is inverted relative to the rest. In other words, every other heat transfer plate is rotated 180 degrees relative to the rest of the plates about its normal. Typically, this is referred to as the heat transfer plates “rotating” relative to each other. In other PHEs, the heat transfer plates are stacked such that the front and rear sides of one heat transfer plate face the front and rear sides of the other heat transfer plates, respectively, and every other heat transfer plate is inverted relative to the rest of the heat transfer plates. In other words, every other heat transfer plate is rotated 180 degrees relative to the rest of the plates about its transverse central axis. Typically, this is referred to as the heat transfer plates “flipping” relative to each other. In other PHEs, heat transfer plates are stacked such that the front and rear sides of one heat transfer plate face the front and rear sides of the other heat transfer plates, respectively. In other words, every other heat transfer plate is rotated 180 degrees relative to the rest of the plates about its longitudinal central axis. Typically, this is referred to as the heat transfer plates “rotating” relative to each other. Parallel flow channels are formed between the heat transfer plates, one channel between each pair of heat transfer plates. Two fluids initially at different temperatures can flow through every other channel to transfer heat from one fluid to the other, these fluids entering and exiting the channels through inlet and outlet port holes in the heat transfer plates.
[0003] Typically, a heat transfer plate includes two end portions and a central portion. The end portions include inlet and outlet port openings and distribution areas with a pattern of protrusions and depressions (such as ridges and valleys) pressed relative to a reference plane of the heat transfer plate. Similarly, the central portion includes heat transfer areas with a heat transfer pattern of protrusions and depressions (such as ridges and valleys) pressed relative to the reference plane. The distribution and ridges and valleys of the heat transfer pattern of a heat transfer plate are arranged to contact the upper and lower adjacent heat transfer plates in contact areas, respectively, within the corresponding distribution and heat transfer areas of the upper and lower adjacent heat transfer plates.
[0004] The primary function of the distribution area of a heat transfer plate is to spread the fluid across the width of the plate before it reaches the heat transfer area, and to collect and guide the fluid out of the channel after it has passed through the heat transfer area. Conversely, the primary function of the heat transfer area is heat transfer. Because the distribution area and the heat transfer area have different primary functions, the distribution pattern typically differs from the heat transfer pattern. The distribution pattern provides relatively low flow resistance in its primary flow direction. A common distribution pattern is the so-called chocolate chip pattern, which provides relatively few elongated contact areas arranged between adjacent heat transfer plates along the primary flow direction. The heat transfer pattern provides an optimal combination of strength, flow resistance, and surface area gain for a given application or task. A common heat transfer pattern is the so-called herringbone pattern, which is versatile and strong due to its relatively dense arrangement of elongated corrugations (resulting in a cross-corrugated pattern in the contact areas between adjacent heat transfer plates). PHE heat transfer plates can be of the same type or two or more different types. If the heat transfer plates are of different types, the difference typically lies in the design of the heat transfer pattern.
[0005] As described in the applicant's PCT application WO 2014 / 067757, at the transition between the distribution area and the heat transfer area, i.e., where the plate pattern changes, the strength of the heat transfer plate assembly may be slightly lower than that of the rest of the assembly due to the uneven distribution of the contact areas. The more dispersed the contact areas are at the transition, the worse the strength may be, as the contact areas may be locally spaced far apart, which could lead to high loads in each contact area. Plate assemblies with similar but mirror-reversed patterns of steep, densely arranged ridges and valleys are typically stronger at the transition than plate assemblies with different patterns of less steep, less densely arranged ridges and valleys. WO2014 / 067757 proposes a solution to this problem by providing a transition area between the distribution area and the heat transfer area of the heat transfer plate, regardless of the plate type (i.e., what the heat transfer pattern looks like). This transition area has a so-called herringbone pattern of steep and densely arranged ridges and valleys. Therefore, regardless of the types of heat transfer plates contained in the plate assembly, the transition from the heat transfer area to the distribution area will be the same and likely relatively strong.
[0006] However, for certain combinations of heat transfer plate channel depth and length / width ratios, the transition region can negatively impact the flow distribution across the heat transfer plate. Typically, different flow paths exist across the heat transfer plate at varying lengths, with longer flow paths associated with lower flow velocities. This can lead to a non-uniform fluid distribution across the heat transfer plate, which in turn can negatively affect the heat transfer capacity of the heat transfer plate. Summary of the Invention
[0007] The objective of this invention is to provide a heat transfer plate that allows for the generation of a plate assembly that provides a strong yet uniform fluid distribution across the plate surface at the transition from the heat transfer region to the distribution region. The fundamental concept of this invention is to vary the flow resistance along the transition region of the heat transfer plate. Therefore, in a plate assembly comprising heat transfer plates, a more uniform flow velocity can be achieved along the transition region, which improves the fluid distribution within the plate assembly. Another objective of this invention is to provide a box comprising two such heat transfer plates and a heat exchanger comprising multiple such boxes. The heat transfer plate (which is also referred to herein simply as a "plate"), the box, and the heat exchanger are defined in the appended claims and discussed below.
[0008] The heat transfer plate according to the invention has a front side and an opposite rear side. It includes an upper distribution region, an upper transition region, and a heat transfer region continuously arranged along the longitudinal central axis of the heat transfer plate. The longitudinal central axis divides the heat transfer plate into a first half and a second half. The upper transition region adjoins the upper distribution region along a first boundary line and the heat transfer region along a second boundary line. The heat transfer region, the upper distribution region, and the upper transition region are respectively provided with a heat transfer corrugated pattern, a distribution corrugated pattern, and a transition corrugated pattern. The transition corrugated pattern differs from the distribution corrugated pattern and the heat transfer corrugated pattern. The transition corrugated pattern includes a top extending in an imaginary top plane facing the front side of the heat transfer plate and a bottom extending in an imaginary bottom plane facing the rear side of the heat transfer plate. The bottom pitch between the bottoms is substantially constant over 50% of the upper transition region. The heat transfer plate is characterized in that the corresponding maximum rear cross-section of the rear corrugated volume between every two adjacent bottoms in the bottom and surrounded by the bottom plane and the heat transfer plate varies, and this rear cross-section is truncated perpendicular to the longitudinal extension of the top extending between the two adjacent bottoms in the bottom. In other words, the heat transfer plate is characterized in that each pair of adjacent bottoms in the bottom, together with the bottom plane and the heat transfer plate, defines a corresponding rear corrugated volume, the rear cross-section of which is truncated perpendicular to the longitudinal extension of the top extending between the two adjacent bottoms in the bottom, and each pair of the two adjacent bottoms in the bottom, together with the bottom plane and the heat transfer plate, defines a corresponding maximum rear cross-section, wherein the maximum rear cross-section varies between the two adjacent bottoms in the bottom. In other words, each pair of adjacent bottoms in the upper transition region defines a corresponding rear corrugated volume between the heat transfer plate and the bottom plane. This rear corrugated volume has a rear cross-section perpendicular to the longitudinal extension of the corresponding bottom. This rear cross-section has a maximum value—the maximum rear cross-section—and can be constant along the longitudinal extension of the corresponding bottom, and therefore equal to the maximum rear cross-section, or vary. The maximum rear cross section defined by the bottom of different pairs is different between pairs.
[0009] The maximum rear cross-sections defined by different pairs of bottoms may all be different. Alternatively, some of the maximum rear cross-sections defined by different pairs of bottoms may be equal to each other and have the same value among two or more different values. The maximum rear cross-sections defined by different pairs of bottoms may gradually increase along the longitudinal extension of the upper transition region, i.e., typically in a direction perpendicular to the longitudinal central axis of the heat transfer plate.
[0010] The first boundary line between the upper transition region and the upper distribution region, just like the second boundary line between the upper transition region and the heat transfer region, can have different forms, such as a straight shape or a curved shape or any combination thereof.
[0011] Transition corrugated patterns, like distribution and heat transfer corrugated patterns, can have different designs. For example, at least most of the top and bottom of a transition corrugated pattern can be elongated or beam-shaped, and / or straight, curved, bent, or angled.
[0012] The bottom pitch between the bottoms, i.e., the distance between two adjacent bottoms, can be substantially constant throughout the upper transition region. This constant bottom pitch allows the heat transfer plate to have a rear cross-section within the upper transition region that is symmetrical with respect to a corresponding volume axis extending perpendicular to the longitudinal and transverse central axes of the heat transfer plate and passing through the center of the top between the bottoms arranged in the corresponding pair. This, in turn, allows for a relatively simple heat transfer plate design. Furthermore, it optimizes the possible surface area increase for the transition corrugation pattern.
[0013] Because the maximum rear cross section varies between the bottoms of different pairs in the upper transition region, while the bottom pitch remains constant for more than half of the upper transition region, the flow resistance along the upper transition region varies, which can optimize the flow distribution across the heat transfer plate and thus optimize the heat transfer capacity of the heat transfer plate.
[0014] The heat transfer plate can be designed such that the top pitch between the tops is substantially constant over more than 50% of the upper transition region. The top pitch between the tops, i.e., the distance between two adjacent tops, can be substantially constant throughout the entire upper transition region. This constant top pitch allows the heat transfer plate to have a rear cross-section in the upper transition region that is symmetrical with respect to a corresponding volume axis extending perpendicular to the longitudinal and transverse central axes of the heat transfer plate and passing through the center of the bottom between the tops arranged in the corresponding pair of tops. This, in turn, allows for a relatively simple heat transfer plate design. Furthermore, it optimizes the possible surface enlargement of the transition corrugation pattern.
[0015] The heat transfer plate can be designed such that the upper transition region includes a first transition sub-region and a second transition sub-region. Each of the first and second transition sub-regions can extend between a first boundary line and a second boundary line. The maximum rear cross-section of more than 50% of the first transition sub-region can be greater than the maximum rear cross-section of more than 50% of the second transition sub-region.
[0016] The maximum rear cross section in the first transition subregion can be greater than the maximum rear cross section in the second transition subregion.
[0017] With this design of the heat transfer plate, the upper transition region can include two or more transition sub-regions, which can define different maximum rear cross-sections designed to optimize the flow distribution across the heat transfer plate. The maximum rear cross-section within the same transition sub-region can be variable or constant.
[0018] The first transition sub-region may be the first outermost sub-region of the upper transition region, and the second transition sub-region may be the second outermost sub-region of the upper transition region. The first and second transition sub-regions may be adjacent to each other. According to this embodiment, the upper transition region is composed of two transition sub-regions that allow for a heat transfer plate with a simple design.
[0019] The heat transfer plate can be designed such that the maximum rear cross-section is constant over 50% of the first transition sub-region. Alternatively, the heat transfer plate can be designed such that the maximum rear cross-section is constant over 50% of the second transition sub-region. These features allow for a heat transfer plate with a simple design.
[0020] The maximum rear cross-section can be constant across substantially the entire first transition subregion. Alternatively, the maximum rear cross-section can be constant across substantially the entire second transition subregion.
[0021] The heat transfer plate allows the first transition sub-region to constitute 30-70% of the upper transition region. This type of interval allows for optimized flow distribution across the heat transfer plate.
[0022] The heat transfer plate can be designed such that the front transition volume in the upper transition region of the first half of the heat transfer plate, and between the heat transfer plate and the top plane, differs from the rear transition volume in the upper transition region of the first half of the heat transfer plate, and between the heat transfer plate and the bottom plane. This design allows for an asymmetric heat transfer plate in the upper transition region.
[0023] As described in the introduction, the heat transfer plates of PHE can be stacked with respect to each other by “rotation,” “flipping,” or “turning.” In a plate assembly containing asymmetric heat transfer plates, the characteristics of the channels between the plates depend on how the plates are stacked. If the plates are “rotated” relative to each other, the channels between the plates can all have substantially the same volume. Conversely, if the plates are “flipped” or “turned” relative to each other, the channels between the plates can have two distinct volumes; every other channel has a smaller volume, while the remaining channels have a larger volume.
[0024] The heat transfer plate according to the invention may include an upper portion, a central portion, and a lower portion continuously arranged along the longitudinal central axis of the heat transfer plate. The upper portion may include a first port hole and a second port hole, and the lower portion may include a third port hole and a fourth port hole. The central portion may include a heat transfer region. Viewed from the front, the heat transfer plate may also include a sealing groove. The sealing groove may include a field sealing groove portion that surrounds the heat transfer region and two of the first, second, third, and fourth port holes. The heat transfer plate may also include a gasket groove arranged to receive a gasket. The gasket groove may include a field gasket groove portion that surrounds the heat transfer region and two of the first, second, third, and fourth port holes not surrounded by the field sealing groove portion. This design of the heat transfer plate allows it to be permanently attached to another heat transfer plate to form a box suitable for use in so-called semi-welded plate heat exchangers.
[0025] The field sealing groove and the field gasket groove may at least partially overlap.
[0026] The second and fourth port holes can be dedicated to the same fluid, while the first and third port holes can be dedicated to the same and another fluid. The second and fourth port holes, like the first and third port holes, can be arranged on opposite sides of the longitudinal central axis of the heat transfer plate. This port hole arrangement allows for so-called diagonal flow type heat transfer plates, as well as heat exchangers comprising heat transfer plates according to the invention that are "rotated" relative to each other. Such heat exchangers typically require two different designs of gaskets, and may also require two different designs of heat transfer plates. Alternatively, the first and third port holes can be arranged on one side of the longitudinal central axis of the heat transfer plate, while the second and fourth port holes can be arranged on the other side. This port hole arrangement allows for so-called parallel flow type heat transfer plates, as well as heat exchangers comprising similar heat transfer plates according to the invention that are "flipped" relative to each other.
[0027] The heat transfer plate can be configured such that the field sealing groove portion of the sealing groove surrounds the second port hole and the fourth port hole. Such a configuration can be advantageous for heat transfer plates arranged to be permanently connected along the sealing groove (e.g., by welding extending within the sealing groove) to another heat transfer plate to form a box.
[0028] In the configuration described above, the field gasket recess portion of the gasket recess (as described above, the gasket recess may be arranged to accommodate a gasket for sealing against another heat transfer plate) may surround the first port hole and the third port hole.
[0029] The heat transfer plate is designed such that the bottom of the field-sealing groove extends in the bottom plane for at least more than half the length of the field-sealing groove. This design facilitates a durable connection of the heat transfer plate to another heat transfer plate.
[0030] The heat transfer plate allows the sealing groove, when viewed from the front side of the heat transfer plate, to include a first annular sealing groove portion surrounding a first port hole and a third annular sealing groove portion surrounding a third port hole. The bottom of the first annular sealing groove portion may extend in a bottom plane for at least more than half its length. Furthermore, the bottom of the third annular sealing groove portion may extend in a bottom plane for at least more than half its length. This design facilitates a durable connection of the heat transfer plate to another heat transfer plate.
[0031] The heat transfer plate can be configured such that the gasket recess further includes a second annular gasket recess portion surrounding the second port hole and a fourth annular gasket recess portion surrounding the fourth port hole. The bottom of the second annular gasket recess portion may extend between a top plane and a bottom plane for at least more than half the length of the second annular gasket recess portion. The bottom of the fourth annular gasket recess portion may extend between a top plane and a bottom plane for at least more than half the length of the fourth annular gasket recess portion. This design allows fluid to flow between the second port hole and the fourth port hole on the rear side of the heat transfer plate.
[0032] The box according to the invention comprises two heat transfer plates. The rear side of one of the two heat transfer plates faces the rear side of the other. The two heat transfer plates are welded to each other along a sealing groove.
[0033] Within the container, one of the two heat transfer plates can rotate 180 degrees about the normal of the other heat transfer plate. In other words, one of the heat transfer plates can be "flipped" or rotated 180 degrees about its transverse central axis. Alternatively, the other of the two heat transfer plates can be "rotated" or rotated 180 degrees about the longitudinal central axis of the other heat transfer plate.
[0034] The heat exchanger according to the invention includes a plurality of heat transfer plates as described above. The heat exchanger also includes gaskets. Each of the gaskets can be arranged in a gasket recess of two adjacent heat transfer plates.
[0035] In a heat exchanger, heat transfer plates can be welded together in pairs, back to back, along sealing grooves to form a box. Furthermore, each gasket can be arranged in a gasket groove of two adjacent boxes within the box.
[0036] The advantages discussed above regarding the different embodiments of the heat transfer plate naturally extend to the box and heat exchanger according to the present invention.
[0037] As a general overview, when this article refers to a part, component, or section of a heat transfer plate extending in a plane, it refers to the main extension of that part, component, or section. Naturally, parts, components, or sections may have local extensions that deviate from the main extension, such as at the transition to another adjacent part, component, or section.
[0038] Furthermore, the phrase "within 50%" is used in various places to describe a general or principal characteristic of a region or subregion. Typically, a much larger percentage (e.g., 75% or 90%, or even 100%) of a region or subregion possesses this characteristic, but deviations in characteristics that result in a percentage less than 100% can also exist. These variations are also covered in this invention.
[0039] It should be emphasized that the advantages discussed above regarding the different embodiments of the heat transfer plate according to the invention become apparent first when the heat transfer plate is arranged in the PHE together with other heat transfer plates (which may also be designed according to the invention), gaskets, and other components required for proper operation of the PHE.
[0040] Other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and from the figures. Attached Figure Description
[0041] The invention will now be described in more detail with reference to the accompanying drawings, in which... Figure 1 This is a schematic front view of a heat exchanger according to the present invention. Figure 2 yes Figure 1 A schematic side view of the heat exchanger in the middle. Figure 3 This is a plan view of the heat transfer plate according to the present invention. Figure 4 yes Figure 1 A schematic side view of a portion of the plate assembly included in the heat exchanger. Figure 5 yes Figure 3 An enlarged view of a portion of the heat transfer plate in the image. Figure 6a It is along Figure 5 The cross section intercepted by line aa in the diagram. Figure 6b It is along Figure 5 The cross-section of line bb in the middle, and Figure 7 This is a plan view of the box according to the present invention. Detailed Implementation
[0042] Figure 1 and Figure 2 A semi-welded plate heat exchanger 2 is shown. It includes a frame plate 4, a pressure plate 6, a heat transfer plate 8 assembly, a fluid inlet and outlet 10, a clamping device 12, an upper rod 14, and a lower rod 16.
[0043] At least most of the heat transfer plates 8 (hereinafter referred to simply as "plates") are similar. As will be discussed further below, the plates 8 are welded in pairs, back to back, to form a tight box, with gaskets arranged between the boxes. The frame plate 4 and the pressure plate 6, and thus the boxes, are pressed together by the tightening device 12, thereby sealing the gaskets between the boxes. Parallel flow channels are formed between the heat transfer plates 8, one channel between each pair of adjacent heat transfer plates 8. Two fluids initially at different temperatures (supplying to / from the plate heat exchanger 2 through fluid inlet and outlet 10) can flow alternately through every other channel to transfer heat from one fluid to the other. These fluids enter / exit the channels through inlet / outlet port holes in the heat transfer plates 8, which form inlet / outlet ports communicating with the fluid inlet and outlet 10 of the plate heat exchanger 2.
[0044] exist Figure 3 The image further illustrates one of the plates 8 of the plate heat exchanger 2, designated 8a. Plate 8a is a generally rectangular stainless steel sheet. It includes first and second opposite long sides 18, 20 and first and second opposite short sides 22, 24. Furthermore, plate 8a has a longitudinal central axis L, which is parallel to the long sides 18, 20 and extends midway between them, dividing plate 8a into a first half 19 and a second half 21. Plate 8a also has a transverse central axis T, which is parallel to the short sides 22, 24 and extends midway between them (and therefore perpendicular to the longitudinal central axis L).
[0045] Plate 8a has a front side 30 (in Figure 3 and Figure 4 (shown in) and the opposite rear side 32 (in) Figure 4(As shown in the diagram). Furthermore, plate 8a includes an upper portion 34, a central portion 36, and a lower portion 38 continuously arranged along the longitudinal central axis L of the heat transfer plate 8a. The upper portion 34 includes a first port hole 40, a second port hole 42, a first insulating region 39, a second insulating region 41, an upper distribution region 44, and an upper transition region 45. A first boundary line 47 defines the boundary between the upper distribution region 44 and the upper transition region 45. The central portion 36 includes a heat transfer region 46. A second boundary line 55 defines the boundary between the upper transition region 45 and the heat transfer region 46. The lower portion 38 includes a third port hole 48, a fourth port hole 50, a third insulating region 49, a fourth insulating region 51, a lower distribution region 52, and a lower transition region 53. The first port hole 40 and the third port hole 48 are arranged on one side of the longitudinal central axis L, while the second port hole 42 and the fourth port hole 50 are arranged on the other side of the longitudinal central axis L.
[0046] The heat transfer plate 8a is pressed in a pressing tool in a conventional manner to give a desired structure, such as different corrugated patterns in different sections of the heat transfer plate. The corrugated patterns are optimized for the specific function of the respective plate sections. Thus, the upper distribution area 44 and the lower distribution area 52 each include a distribution corrugated pattern suitable for an optimized fluid distribution across the heat transfer plate 8a. Furthermore, the heat transfer area 46 includes a heat transfer corrugated pattern suitable for optimized heat transfer between two fluids flowing on opposite sides of the heat transfer plate 8a. The upper transition area 45 and the lower transition area 53 include transition corrugated patterns suitable for an optimized combination of intensity and fluid distribution. Additionally, the first insulating area 39, the second insulating area 41, the third insulating area 49, and the fourth insulating area 51 each include a corrugated pattern suitable for conveying fluid between the port orifice and the distribution area with the lowest possible pressure drop. Furthermore, the plate 8a includes an outer edge portion 54 extending along the outer edge 56 of the plate. The outer edge portion 54 includes an imaginary parallel top plane TP and a bottom plane BP. Figure 4 Corrugations 58 extending between them, with the top plane TP and bottom plane BP facing the front side 30 and rear side 32 of plate 8a, respectively. These corrugations 58 are arranged to abut against the corrugations of adjacent plates 8b and 8c in the plate assembly of the plate heat exchanger 2. Similarly, refer to Figure 3 and Figure 4 The transition corrugated pattern includes corrugations, more specifically, alternating ridges with tops 60 and valleys with bottoms 62 when viewed from the front side 30 of plate 8a, these tops 60 and bottoms 62 extending in the top plane TP and bottom plane BP, respectively. These tops 60 and bottoms 62 are arranged to abut the tops and bottoms of adjacent plates 8b and 8c in the plate assembly of the plate heat exchanger 2. Furthermore, the distribution and heat transfer corrugated pattern includes corrugations arranged to abut the corrugations of adjacent plates in the plate assembly of the plate heat exchanger 2. However, this is not discussed further herein.
[0047] In the following text, reference will be made to Figure 5 , Figure 6a and Figure 6b To further describe the transition ripple pattern. Figure 5 This includes an enlarged view of the upper transition region 45, which comprises a first transition sub-region A and a second transition sub-region B. The first transition sub-region A and the second transition sub-region B are located along the transverse central axis T of plate 8a. Figure 3 The transition regions 45 and 66 are arranged continuously, with each of them extending between the first boundary line 47 and the second boundary line 55. A line cc extending between two adjacent tops in the top 60 defines the boundary between the first transition sub-region A and the second transition sub-region B. On a particular heat transfer plate 8a, the line cc extends approximately in the central portion of the plate 8a, such that the first transition sub-region A extends substantially on the first half 19 of the plate 8a, while the second transition sub-region B extends substantially on the second half 21 of the plate 8a. Thus, the first transition sub-region A and the second transition sub-region B each occupy approximately 50% of the upper transition region 45 of the plate 8a. However, on another plate designed according to the invention, the first transition sub-region A may occupy anywhere between 30% and 70% of the upper transition region 45, while the second transition sub-region B may occupy the remaining portion of the upper transition region 45.
[0048] Reference Figure 6a and 6bThe top pitch tp between the tops 60 is constant within the upper transition region 45, and therefore identical within transition sub-regions A and B. Similarly, the bottom pitch bp between the bottoms 62 is constant within the upper transition region 45, and therefore identical within transition sub-regions A and B, and equal to the top pitch tp. Again, the transition corrugation pattern differs within transition sub-regions A and B. The upper transition region 45 of plate 8a, together with the top plane TP, defines a volume comprising a front corrugated volume FV extending between the tops 60, with one front corrugated volume FV extending between every two adjacent tops in the tops 60. Similarly, the upper transition region 45 of plate 8a, together with the bottom plane BP, defines a volume comprising a rear corrugated volume BV extending between the bottoms 62, with one rear corrugated volume BV extending between every two adjacent bottoms in the bottoms 62. Each of the front corrugated volumes FV has a front cross section FC, which is cut perpendicularly to the longitudinal extension lb of the bottom 62 extending between two adjacent tops 60 defining the respective front corrugated volume FV. The front cross section FC may vary between a minimum and a maximum front cross section, or, as in this case, the longitudinal extension lb along the respective bottom 62 may be constant. Each of the rear corrugated volumes BV has a rear cross section BC, which is cut perpendicularly to the longitudinal extension lt of the top 60 extending between two adjacent bottoms 62 defining the respective rear corrugated volume BV. The rear cross section BC may vary between a minimum and a maximum rear cross section, or, as in this case, the longitudinal extension lt along the respective top 60 may be constant.
[0049] Even for the same front corrugated volume FV, the front cross section FC is constant. The front cross section FC varies between different front corrugated volumes FV within the upper transition region 45, so that it has a substantially constant value in the first transition sub-region A and another substantially constant value in the second transition sub-region B. More specifically, the front cross section FC is 10-40% larger in the second transition sub-region B than in the first transition sub-region A, in this case, 30%. Furthermore, even for the same rear corrugated volume BV, the rear cross section BC is constant. The rear cross section BC varies between different rear corrugated volumes BV within the upper transition region 45, so that it has a substantially constant value in the first transition sub-region A and another substantially constant value in the second transition sub-region B. More specifically, the rear cross section BC is 10-40% larger in the first transition sub-region A than in the second transition sub-region B, in this case, 30%.
[0050] Reference Figure 3Viewed from the front side 30 of the plate, the sealing groove 64 is pressed into the plate 8a. The sealing groove 64 includes a field sealing groove portion 64a, a first annular sealing groove portion 64b, and a third annular sealing groove portion 64c. The sealing groove 64... Figure 3 The field sealing groove portion 64a is shown in the diagram. It surrounds the heat transfer region 46 and the second port hole 42 and the fourth port hole 50. The bottom 66a of the field sealing groove portion 64a extends along its entire length along the bottom plane BP. Figure 4 The first annular sealing groove portion 64b surrounds the first port hole 40. The bottom 66b of the first annular sealing groove portion 64b extends along the entire length of the first annular sealing groove portion 64b in the bottom plane BP. The third annular sealing groove portion 64c surrounds the third port hole 48. The bottom 66c of the third annular sealing groove portion 64c extends along the entire length of the third annular sealing groove portion 64c in the bottom plane BP.
[0051] In addition, refer to Figure 3 and Figure 7 Viewed from the front side 30 of the plate, a gasket groove 68 for receiving the gasket 59 (including a field gasket portion and two annular gasket portions) is also pressed into the plate 8a. The gasket groove 68 includes a field gasket groove portion 68a, a second annular gasket groove portion 68b, and a fourth annular gasket groove portion 68c. The field gasket groove portion 68a surrounds the heat transfer region 46 and the first port hole 40 and the third port hole 48. The field gasket groove portion 68a partially overlaps with the field sealing groove portion 64a. Therefore, the bottom 70a of the field gasket groove portion 68a is on the bottom plane BP (…). Figure 4 Extending along the second annular gasket recess 68a, the field gasket recess 68a coincides with the field sealing recess 64a. In fact, except at the two diagonal segments 68a' of the field gasket recess 68a, the bottom 70a of the field gasket recess 68a extends in the bottom plane BP, and along the two diagonal segments 68a', the bottom 70a extends between the top plane TP and the bottom plane BP (here, midway between the top plane TP and the bottom plane BP). The second annular gasket recess 68b surrounds the second port hole 42. The bottom 70b of the second annular gasket recess 68b extends along its entire length between the top plane TP and the bottom plane BP (here, midway between the top plane TP and the bottom plane BP). The fourth annular gasket recess 68c surrounds the fourth port hole 50. The bottom 70c of the fourth annular gasket groove portion 68c extends along the entire length of the fourth annular gasket groove portion 68c between the top plane TP and the bottom plane BP (in this case, midway between the top plane TP and the bottom plane BP).
[0052] The lower portion 38 of plate 8a is a mirror image of the upper portion 34 of plate 8a along the transverse central axis T of plate 8a. Furthermore, plate 8a is a so-called asymmetric plate, meaning that the front volume defined between plate 8a and the top plane TP is different from the rear volume defined between plate 8a and the back plane BP. Looking at the upper transition region 45, the front transition volume on the first half 19 of plate 8a (which is essentially the aggregated volume of the front corrugated volume FV within the first transition sub-region A) is different from the rear transition volume on the first half 19 of plate 8a (which is essentially the aggregated volume of the rear corrugated volume BV within the first transition sub-region A). Similarly, still looking at the upper transition region 45, the front transition volume on the second half 21 of plate 8a (which is essentially the aggregated volume of the front corrugated volume FV within the second transition sub-region B) is different from the rear transition volume on the second half 21 of plate 8a (which is essentially the aggregated volume of the rear corrugated volume BV within the second transition sub-region B).
[0053] In the plate assembly of the plate heat exchanger 2, the plates 8 are arranged such that the front side 30 and rear side 32 of one of the plates 8 face the front and rear sides of the adjacent heat transfer plates, respectively. Furthermore, every other plate 8 is positioned relative to a reference orientation around the normal direction. Figure 3 The normal direction N of the plane is inverted and rotated 180 degrees. In other words, every other plate 8 is "flipped" relative to the rest of the plates, that is, rotated 180 degrees around its transverse central axis.
[0054] As mentioned above, the plates 8 of the assembly are welded together in pairs along their respective sealing grooves 64, rear side 32 to rear side 32, to form a box 57. Figure 7 One of the boxes 57 is shown, which includes Figure 3 Plate 8a shown in the figure and in Figure 4 Visible in (but in Figure 7 Plate 8c (not visible in the image). Plate 8c is "flipped" relative to plate 8a. In the plate assembly of the plate heat exchanger 2, the welded box 57 is separated by gaskets 59, at least most of which are similar, one of which is in... Figure 7 As shown in the diagram. Consistent with the above, the gasket 59 is accommodated in the gasket groove 68 of the plate 8, as... Figure 7 As shown in the diagram. Therefore, the heat exchanger 2 includes two different types of channels: welded channels inside the housing 57 and gasketed channels between the housings 57.
[0055] Plates 8 are in contact with each other in the contact areas. In the upper and lower distribution areas 44 and 52, which have a so-called chocolate-shaped corrugated pattern, the contact areas are elongated. In the heat transfer area 46, which has a so-called herringbone-shaped heat transfer corrugated pattern, the contact areas are dotted. In the upper and lower transition areas 45 and 53, which have a transition corrugated pattern with elongated beams, the contact areas are dotted. Consistent with the initial discussion, providing upper and lower transition areas 45 and 53 on plate 8 makes the plate assembly mechanically strong between the heat transfer areas and each of the upper and lower distribution areas. Furthermore, since the transition corrugated pattern is designed as described above to provide varying flow resistance in the upper and lower transition areas 45 and 53, the fluid flow distribution within the channels of the plate assembly is improved. More specifically, refer to... Figure 3 and Figure 5 There exist an infinite number of distinct, non-separated flow paths for conveying fluid from the first port hole 40 of plate 8a across the front side 30 of plate 8a to the third port hole 48 of plate 8a. Shorter flow paths are guided along the first long side 18 and through the first transition sub-region A of the upper and lower transition regions 45 and 53 of plate 8a, while longer flow paths are guided along the second long side 20 and through the second transition sub-region B of the upper and lower transition regions 45 and 53 of plate 8a. The inventive design of the transition corrugation pattern will cause variations in flow resistance through the upper and lower transition regions 45 and 53 of plate 8a, such that shorter flow paths provide higher flow resistance and longer flow paths provide lower flow resistance. This, in turn, optimizes the flow distribution across the front side 30 of plate 8a. Correspondingly, there will be shorter and longer flow paths from the fourth port hole 50 of plate 8a across the rear side 32 of plate 8a to the second port hole 42 of plate 8a. For shorter flow paths, the flow resistance will be higher, and for longer flow paths, the flow resistance will be lower, which will optimize the flow distribution across the rear side 32 of plate 8a.
[0056] The embodiments described above are to be considered as examples only. Those skilled in the art will recognize that the described embodiments can be varied and combined in many ways without departing from the inventive concept.
[0057] As examples, the distribution, transition, and heat transfer corrugated patterns specified above are merely exemplary. Naturally, the invention can be applied in conjunction with other types of corrugated patterns. As an example, a transition corrugated pattern may consist of straight beams that all extend at the same angle of inclination relative to the longitudinal central axis of the heat transfer plate, rather than just some of them extending at the same angle of inclination relative to the longitudinal central axis as shown in the figures. A transition corrugated pattern may also consist of beams extending at different angles of inclination relative to the longitudinal central axis of the plate. As another example, a transition corrugated pattern may include arrow-shaped beams, and thus top and bottom, with these arrows pointing to one of the first and second long sides of the heat transfer plate, or to one of the first and second short sides of the heat transfer plate.
[0058] The upper transition region of the plate shown in the figure includes first and second (i.e., two) transition sub-regions. Therefore, the first transition sub-region is the first outermost sub-region of the upper transition region, and the second transition sub-region is the second outermost sub-region of the upper transition region, with the first and second transition sub-regions adjacent to each other. However, alternative designs for the upper transition region are possible. For example, the plate according to the invention may include more than two transition sub-regions having different values of the maximum rear cross-section. The maximum rear cross-section within the same transition sub-region may be constant or variable. The maximum rear cross-section within one or more transition sub-regions may be variable, while the maximum rear cross-section within one or more transition sub-regions may be constant.
[0059] The first boundary line of the plate shown in the figure has a curved portion and a straight portion, while the second boundary line is straight. The first and / or second boundary lines may have alternative designs on other plates according to the invention. As an example, both the first and second boundary lines may be straight. As another example, both the first and second boundary lines may be curved. The first and second boundary lines may be parallel.
[0060] The plate heat exchanger described above includes only one type of plate. Naturally, a plate heat exchanger can be modified to include two or more different types of heat transfer plates arranged alternately. Furthermore, the heat transfer plates can be made of materials other than stainless steel.
[0061] This invention can be used in conjunction with other types of plate heat exchangers besides semi-welded plate heat exchangers, such as fully welded, (fully) gasketed, and brazed plate heat exchangers.
[0062] The bottom of the field gasket recess does not need to extend midway between the top and bottom planes at the two diagonal sections of the field gasket recess, but can instead extend closer to one of the top and bottom planes. Similarly, the bottom of the second annular gasket recess, like the bottom of the fourth annular gasket recess, does not need to extend midway between the top and bottom planes along its entire length, but can instead extend along a portion of its length or its entire length in another plane, for example, closer to the top plane than the bottom plane. If the invention is used in conjunction with a gasketed plate heat exchanger, the bottom of the field gasket recess does not need to extend in the bottom plane at all, but instead extends along its entire length between the top and bottom planes.
[0063] It should be emphasized that the terms "before," "after," "upper," "lower," "first," "second," and "third" in this article are only used to distinguish details and are not used to indicate any kind of orientation or the order between details.
[0064] Furthermore, it should be emphasized that details unrelated to the present invention have been omitted, and the figures are schematic and not drawn to scale. It should also be noted that some figures are simplified than others. Therefore, some components may be shown in one figure and omitted in another.
Claims
1. A heat transfer plate (8, 8a) having a front side (30), a rear side (32), and including an upper distribution region (44), an upper transition region (45), and a heat transfer region (46) continuously arranged along a longitudinal central axis (L) of the heat transfer plate (8, 8a), the longitudinal central axis (L) dividing the heat transfer plate into a first half (19) and a second half (21), the upper transition region (45) being adjacent to the upper distribution region (44) along a first boundary line (47) and adjacent to the heat transfer region (46) along a second boundary line (55), the heat transfer region (46), the upper distribution region (44), the upper transition region (45), the upper transition region (46), the upper transition ... Partial fabric area (44) and the upper transition area (45) are respectively provided with heat transfer corrugated pattern, distribution corrugated pattern and transition corrugated pattern, the transition corrugated pattern is different from the distribution corrugated pattern and the heat transfer corrugated pattern and includes a top (60) extending in an imaginary top plane (TP) facing the front side (30) of the heat transfer plate (8, 8a) and a bottom (62) extending in an imaginary bottom plane (BP) facing the rear side (32) of the heat transfer plate (8, 8a), the bottom pitch (bp) between the bottoms (62) is substantially constant in more than 50% of the upper transition area (45), characterized in that, The maximum rear cross section (BC) of the rear corrugated volume (BV) between every two adjacent bottoms in the bottom (62) and surrounded by the bottom plane (BP) and the heat transfer plates (8, 8a) varies, and the rear cross section (BC) is cut perpendicular to the longitudinal extension (lt) of the top (60) extending between the two adjacent bottoms in the bottom (62).
2. The heat transfer plate (8, 8a) according to claim 1, wherein, The top pitch (tp) between the tops (60) is substantially constant over 50% of the upper transition region (45).
3. The heat transfer plate (8, 8a) according to any one of the preceding claims, wherein, The upper transition region (45) includes a first transition sub-region (A) and a second transition sub-region (B), each of the first transition sub-region (A) and the second transition sub-region (B) extending between the first boundary line (47) and the second boundary line (55), wherein more than 50% of the maximum rear cross section (BC) in the first transition sub-region (A) is greater than more than 50% of the maximum rear cross section (BC) in the second transition sub-region (B).
4. The heat transfer plate (8, 8a) according to claim 3, wherein, The first transition sub-region (A) is the first outermost sub-region of the upper transition region (45) and the second transition sub-region (B) is the second outermost sub-region of the upper transition region (45), and the first transition sub-region (A) and the second transition sub-region (B) are adjacent to each other.
5. The heat transfer plate (8, 8a) according to any one of claims 3-4, wherein, The maximum rear cross section (BC) is constant within more than 50% of the first transition sub-region (A).
6. The heat transfer plate (8, 8a) according to any one of claims 3-5, wherein, The maximum rear cross section (BC) is constant within more than 50% of the second transition sub-region (B).
7. The heat transfer plate (8, 8a) according to any one of claims 3-6, wherein, The first transition sub-region (A) constitutes 30-70% of the upper transition region (45).
8. The heat transfer plate (8, 8a) according to any one of the preceding claims, wherein, The front transition volume in the upper transition region (45) on the first half (19) of the heat transfer plate (8, 8a) and between the heat transfer plate (8, 8a) and the top plane (TP) is different from the rear transition volume in the upper transition region (45) on the first half (19) of the heat transfer plate (8, 8a) and between the heat transfer plate (8, 8a) and the bottom plane (BP).
9. The heat transfer plate (8, 8a) according to any one of the preceding claims, comprising an upper portion (34), a central portion (36), and a lower portion (38) continuously arranged along the longitudinal central axis (L) of the heat transfer plate (8, 8a), wherein the upper portion (34) includes a first port hole (40) and a second port hole (42), the lower portion (38) includes a third port hole (48) and a fourth port hole (50), and the central portion (36) includes the heat transfer region (46), wherein, When viewed from the front side (30), the heat transfer plate (8, 8a) further includes a sealing groove (64), the sealing groove (64) including a field sealing groove portion (64a) surrounding the heat transfer area (46) and two of the first port hole (40), the second port hole (42), the third port hole (48) and the fourth port hole (50), and wherein the heat transfer plate (8, 8a) further includes a gasket groove (68), the gasket groove (68) including a field gasket groove portion (68a), the field gasket groove portion (68a) surrounding the heat transfer area (46) and two of the first port hole (40), the second port hole (42), the third port hole (48) and the fourth port hole (50) not surrounded by the field sealing groove portion (64a).
10. The heat transfer plate (8, 8a) according to claim 9, wherein, The first port hole (40) and the third port hole (48) are arranged on one side of the longitudinal central axis (L) of the heat transfer plate (8, 8a), and the second port hole (42) and the fourth port hole (50) are arranged on the other side of the longitudinal central axis (L) of the heat transfer plate (8, 8a).
11. The heat transfer plate (8, 8a) according to any one of claims 9-10, wherein, The field sealing groove portion (64a) surrounds the second port hole (42) and the fourth port hole (50).
12. The heat transfer plate (8, 8a) according to any one of claims 9-11, wherein, The bottom (66a) of the field sealing groove portion (64a) extends in the bottom plane (BP) for at least more than half of the length of the field sealing groove portion (64a).
13. The heat transfer plate (8, 8a) according to any one of claims 9-12, wherein, Viewed from the front side (30) of the heat transfer plates (8, 8a), the sealing groove (64) further includes a first annular sealing groove portion (64b) surrounding the first port hole (40) and a third annular sealing groove portion (64c) surrounding the third port hole (48), wherein the bottom (66b) of the first annular sealing groove portion (64b) extends in the bottom plane (BP) for at least more than half the length of the first annular sealing groove portion (64b), and the bottom (66c) of the third annular sealing groove portion (64c) extends in the bottom plane (BP) for at least more than half the length of the third annular sealing groove portion (64c).
14. A box (57) comprising two heat transfer plates (8, 8a) according to any one of claims 9-13, wherein, The rear side (32) of one of the two heat transfer plates (8, 8a) faces the rear side (32) of the other of the two heat transfer plates (8, 8a), and the two heat transfer plates (8, 8a) are welded to each other along the sealing groove (64).
15. A heat exchanger (2) comprising a plurality of heat transfer plates (8, 8a) according to any one of claims 1-13 and gaskets (59), each of the gaskets (59) being disposed in a gasket groove (68) of two adjacent heat transfer plates in the heat transfer plates (8, 8a).