Flow element
The flow element addresses material thinning and cracking issues by tapering raised sections in height and width, improving durability and reducing manufacturing rejects and costs in electrochemical systems.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-09-10
- Publication Date
- 2026-04-02
AI Technical Summary
Existing flow elements, particularly bipolar plates in electrochemical systems, face issues with material thinning and cracking at transition zones, leading to reduced durability and increased manufacturing rejects, and require high material and energy expenditure.
The flow element features a flat element with specially designed transition zones where the raised sections taper in height and width over varying lengths, minimizing thinning and cracking during manufacturing, and allowing for better support of adjacent cell components.
This design enhances durability, reduces manufacturing rejects, and lowers material and energy consumption while maintaining effective fluid distribution and electrical conductivity.
Smart Images
Figure EP2025075705_02042026_PF_FP_ABST
Abstract
Description
[0001] Flow element
[0002] The present invention relates to a flow element, which may in particular be a bipolar plate element for an electrochemical system, e.g. for a fuel cell system or an electrolysis system.
[0003] Document DE 102023207 174 A1 describes a separator plate for an electrochemical system, comprising a plurality of parallel and adjacent channels designed to guide a fluid at least along a region of the separator plate, wherein the channels each have a depth, a longitudinal extent, a channel bottom and two side walls, wherein the following applies to at least one of the channels:
[0004] - the depth of the canal is essentially constant in a first section of the canal along its longitudinal extent,
[0005] - the canal floor is essentially flat in the first section of the canal and
[0006] - the depth of the channel decreases along its longitudinal extent in a transition area adjacent to the first area, causing a channel floor extension to be curved in the transition area, wherein the channel floor extension in the transition area is curved in such a way that, if surface lines of the channel floor running parallel to each other along the longitudinal extent of the channel and in the first area are continued in the area of the channel floor extension, the surface lines in the area of the channel floor extension also run substantially parallel to each other.
[0007] The specification "essentially parallel" is intended, according to document DE 102023207 174 A1, to allow deviations from parallelism of a maximum of 12°. Such deviations from parallelism can arise, for example, because as the channel depth decreases, the width of the channel, or more precisely, the channel bottom extension, can increase slightly due to the reduced embossing height. The aforementioned deviations may apply to any two surface lines from all surface lines of the channel. In particular, the aforementioned deviations may apply to two surface lines of the channel that are at most far apart. It is described that the channel bottom extension should have a constant width in the transition zone.In summary, it should be noted regarding document DE 102023 207 174 A1 that for an element (bottom, wall) located in the first area of the channels described therein, a corresponding element (bottom extension, wall extension) is provided in the transition area, which connects to the element (bottom, wall) located in the first area along the longitudinal extent of the channel. For example, a channel bottom extension connects to the channel bottom and a side wall extension connects to the side wall.
[0008] The document DE 102023 207 174 A1 states that the separator plate described therein should have a higher durability and should exhibit higher process stability and reduced rejects in manufacturing.
[0009] There is a desire for further improvements.
[0010] The present invention is based on the objective of providing an effective flow element, which can be, for example, a bipolar plate element for an electrochemical system, in a simple manner.
[0011] The flow element can be effective, for example, with regard to the distribution of an operating fluid on an electrode surface of the electrochemical system and / or with regard to the durability of the flow element and / or with regard to its high electrical conductivity.
[0012] The flow element can be provided in a simple manner, particularly with regard to a low rate of rejects during production, such as flow elements that are unusable in electrochemical systems due to excessive thinning or cracking, and / or with regard to the low material and / or energy expenditure required for production.
[0013] The problem is solved according to the invention by the flow element according to the relevant independent claim.
[0014] The invention is based on the finding that, particularly with metallic bipolar plates featuring embossed channel structures, limitations exist in the degree of possible material deformation. Undesirable thinning of the material can occur, especially at the ends of raised sections. In the transition zones leading to the ends, the outermost edge region—that is, the transition from a base level to a raised section—proved to be particularly critical, as undesirable thinning was especially evident there.
[0015] The structures known from document DE 102023207 174 A1 did not prove to be entirely satisfactory.
[0016] In connection with the invention, it was found in particular that with specially designed transition zones, the undesirable thinning during forming can be avoided and greater embossing depths can thereby be achieved.
[0017] Alternatively or additionally, according to the invention, an approximately planar raised surface can be provided particularly well. This allows, for example, adjacent cell components in a fuel cell stack, which rest on the raised surface, to rest better and / or be supported.
[0018] The flow element includes a flat element. The flat element can, in particular, be a metallic flat element.
[0019] The flat element can be, for example, a sheet metal forming product.
[0020] The flat element can, for example, consist of a sheet metal forming product.
[0021] The thickness of the flat element, e.g. the sheet metal forming product, can preferably be at least 0.05 mm, more preferably at least 0.08 mm, e.g. at least 0.1 mm.
[0022] The thickness of the flat element, e.g., the sheet metal forming product, can preferably be at most 1 mm, more preferably at most 0.6 mm, e.g., at most 0.4 mm.
[0023] The thickness of the flat element, e.g., the sheet metal forming product, can preferably be 0.05 mm to 1 mm, more preferably 0.08 mm to 0.6 mm, e.g., 0.1 mm to 0.4 mm. The thickness specifications refer to the thickness of the flat element, e.g., the sheet metal forming product, in an unformed section of the flat element, e.g., the sheet metal forming product.
[0024] The flat element, e.g., the sheet metal forming product, may preferably contain, consist of, and / or be wholly or partially manufactured from one of the following metals and metal alloys: austenitic stainless steel, e.g., selected from alloys 304L, 316L, 904L, and 31OS; ferritic stainless steel, e.g., selected from alloys 430, 441, 444, and Crofer; nickel-based alloy, e.g., selected from alloys 200 / 201, 286, 600, and 625.
[0025] Titanium, e.g. selected from alloys Grade 1 or Grade 2,
[0026] - Aluminum alloy, e.g. selected from the alloys of the 1000 series and the 3000 series.
[0027] The flat element has a raised section, and it may be advantageous if the raised section, for example, borders a channel of the flow element on at least one side of the channel.
[0028] Preferably, the raised section is a ridge, e.g., a ridge introduced into the flat element by forming, e.g., embossed.
[0029] The elevation rises in a vertical direction orthogonal to two main extension directions of the flat element, starting from a base level to a maximum level of the elevation.
[0030] The main directions of extension can be orthogonal to each other.
[0031] The base level can be, in particular, a base level taken at the base of the elevation, e.g., a measurable one. The phrase "at the base of the elevation" can refer, in particular, to a surface of the flat element directly adjacent to the elevation. This surface of the flat element directly adjacent to the elevation can transition at the base of the elevation into the outer surface of the elevation described herein. The elevation can have an extension zone. In particular, within the extension zone, the elevation can rise vertically, orthogonal to the two principal extension directions of the flat element, from the base level to the highest level.
[0032] The highest level of the elevation can refer to a plateau formed at the very top of the elevation. The elevation may exhibit this plateau particularly in its extent zone.
[0033] The term "in particular" is used in this description and the attached claims preferably to describe optional features.
[0034] The elevation extends in a longitudinal direction essentially parallel to a principal plane defined by the two principal extension directions of the flat element, or in a principal plane defined by the two principal extension directions of the flat element, to one end of the elevation.
[0035] The increase has a transition zone.
[0036] In an elevation transition section of the transition zone, the height of the elevation decreases, for example, until it reaches zero at the end, where the elevation is measured in the vertical direction. Alternatively or additionally, in a latitudinal transition section of the transition zone, the width of the elevation changes, for example, until it reaches zero at the end, where the width is measured in a latitudinal direction parallel to the main plane and orthogonal to the longitudinal direction in the base level.
[0037] The statement that the height of the elevation is taken in the vertical direction can, for example, mean that the height of the elevation is measurable in the vertical direction.
[0038] The statement that the width of the elevation is measured in a lateral direction can, for example, mean that the width of the elevation is measurable in the lateral direction. The width transition section can advantageously include a width reduction section in which the width of the elevation decreases with increasing proximity to the end of the elevation.
[0039] It can be advantageous if the width transition section has a width reduction section in which the width of the elevation decreases in an approximately semicircular manner with increasing proximity to the end of the elevation, wherein an approximately semicircular reduction is present if the elevation at the base of the elevation runs completely between two concentric circles of different sizes lying in the base level throughout the entire width reduction section, wherein the diameter of the smaller circle is at least 55%, in particular at least 67%, preferably at least 73%, most preferably at least 83%, e.g. at least 87% of the diameter of the larger circle.
[0040] It can be particularly advantageous if the width transition section has a width reduction section in which the width of the elevation decreases in an approximately semicircular manner with increasing proximity to the end of the elevation, wherein an approximately semicircular reduction is present if the elevation at half its height, in particular in an intermediate plane oriented parallel to the main plane which lies between the base level and the highest level, runs completely between two concentric circles of different sizes lying in the intermediate plane throughout the entire width reduction section, wherein the diameter of the smaller circle is at least 67%, preferably at least 73%, particularly preferably at least 83%, e.g. at least 87% of the diameter of the larger circle.
[0041] The width transition section may include a width widening section in which the width of the elevation increases with increasing proximity to the end of the elevation.
[0042] The width transition section may include an intermediate extension section in which the width of the elevation remains essentially constant as it approaches the end of the elevation. It may be advantageous if, in the height transition section, the height of the elevation decreases until it reaches zero at the end, and if, in the width transition section, the width of the elevation changes until it reaches zero at the end.
[0043] Advantageously, the decrease in the height of the elevation in the elevation transition section can be a continuous decrease in the height of the elevation until the height of the elevation has decreased to zero at the end.
[0044] A continuous decrease refers in particular to a decrease that occurs essentially without an intermediate increase or without an intermediate rise.
[0045] The decrease occurs essentially without an intermediate rise if, along the longitudinal direction towards the end of the elevation, the height of the elevation at no point closer to the end of the elevation is more than 15% higher than at any point further away from the end of the elevation.
[0046] Advantageously, the decrease occurs essentially without intermediate increases if, along the longitudinal direction towards the end of the increase, the height of the increase at no point closer to the end of the increase is more than 10% higher than at any point further away from the end of the increase.
[0047] The decrease is particularly advantageous if, along the longitudinal direction towards the end of the increase, the height of the increase is not more than 5% higher at any point closer to the end than at any point further away from the end.
[0048] The decrease occurs without intermediate rises if, along the longitudinal direction towards the end of the rise, the height of the rise is not higher at any point closer to the end than at any point further away from the end. Advantageously, when determining any intermediate rises, all cross-sections that intersect the elevation transition section perpendicular to the longitudinal direction are considered, and the highest points of these cross-sections are compared.
[0049] The amount of the increase can, in particular, be a measurable increase taken from the base level to the maximum level.
[0050] It can be advantageous if a height transition length, which is a length of the height transition section taken in the longitudinal direction, e.g. measurable, is greater or smaller than a width transition length, which is a length of the width transition section taken in the longitudinal direction, e.g. measurable.
[0051] Advantageously, both transition lengths, i.e., the height transition length and the width transition length, can be measured in the longitudinal direction at the base level, e.g.
[0052] It can be advantageous if one of the two lengths chosen under the altitude transition length and the latitude transition length is at least 115% of the other of the two lengths chosen under the altitude transition length and the latitude transition length.
[0053] It can be particularly advantageous if one of the two lengths chosen under the altitude transition length and the width transition length is at least 120% of the other of the two lengths chosen under the altitude transition length and the width transition length.
[0054] It can be particularly advantageous if one of the two lengths chosen under the altitude transition length and the latitude transition length is at least 130% of the other of the two lengths chosen under the altitude transition length and the latitude transition length.
[0055] It can be extremely advantageous if one of the two lengths chosen under the altitude transition length and the latitude transition length is at least 170% of the other of the two lengths chosen under the altitude transition length and the latitude transition length.
[0056] For example, one of the two lengths chosen under the altitude transition length and the latitude transition length may be at least 180% of the other of the two lengths chosen under the altitude transition length and the latitude transition length.
[0057] One of the two transition lengths, namely the height transition length or the width transition length, can advantageously be at least 115%, particularly advantageously at least 120%, very particularly advantageously at least 130%, extremely advantageously at least 170%, e.g. at least 180%, of the other of the two transition lengths, namely the height transition length or the width transition length.
[0058] It can be advantageous if the length ratio, calculated by dividing the altitude transition length by the width transition length, is at least 1.3 or at most 0.8.
[0059] It can be particularly advantageous if the length ratio, calculated by dividing the altitude transition length by the width transition length, is at least 1.8 or at most 0.6.
[0060] Advantageously, the length ratio can be at most 7 if it is at least 1.3 or at least 1.8. It can advantageously be between 1.3 and 7, for example 1.8 and 7.
[0061] Advantageously, the length ratio can be at least 0.1 if it is at most 0.8 or at most 0.6. It can advantageously be between 0.1 and 0.8, for example, between 0.1 and 0.6.
[0062] It was found that fewer thinnings and cracks form at the ends of raised sections during the manufacturing of the flow element if the raised sections do not simultaneously taper from their maximum height and narrow from their maximum width at their ends. This is especially true if the decrease in height and width occurs over sections of the transition zone of varying lengths.
[0063] When forming a flat element along one direction (e.g., longitudinal direction), this process can partially occur in an area of the element that does not also need to be bent in the other direction (e.g., transversely to the longitudinal direction). Undesirable thinning and cracking occur particularly where the flat element is bent in multiple directions. Therefore, if the width transition length and the height transition length differ from each other—as described in connection with the invention—this can partially prevent forming in multiple directions. This can advantageously help to prevent thinning and cracking.
[0064] It can be advantageous if, in a width expansion section of the width transition section, the width of the elevation increases with increasing proximity to the end of the elevation.
[0065] This can lead, in particular, to the raised section in the transition zone being wider overall than if the raised section were designed without any widening section. Consequently, a larger area of the flat element is available for forming in different directions at the end of the raised section. Thus, a larger area can be formed, but less forming effort is required per defined area (e.g., one square millimeter), resulting in fewer thinning areas and cracks.
[0066] It can be advantageous if the increase in the width extension section of the width transition section is extended on both sides.
[0067] It can be advantageous if, in the width expansion section of the width transition section, the elevation is expanded on one side or is expanded more on one side of the elevation than on the other side of the elevation.
[0068] It can be advantageous if, at an end of the lateral transition section located longitudinally away from the end of the elevation, the residual height of the elevation, measured from the base level, is at most 95%, e.g., at most 75%, of the distance from the base level to the highest level.
[0069] It can be advantageous if, at an end of the width reduction section located longitudinally away from the end of the elevation, the residual height of the elevation, measured from the base level, is at most 95%, e.g., at most 75%, of the distance from the base level to the highest level.
[0070] In particular, if the latitudinal transition section includes a latitudinal expansion section, in a transition from the latitudinal expansion section to the latitudinal reduction section or in a transition from the intermediate expansion section to the latitudinal reduction section, the residual height of the increase, measured from the base level, e.g., may be at most 95%, e.g., at most 75%, of the distance from the base level to the highest level.
[0071] The distance from the base level to the highest level can, in particular, be a difference in altitude, e.g., a measurable difference. This distance can correspond to the elevation height mentioned herein.
[0072] It can be advantageous if the flat element within the height transition section in a frontal zone runs continuously straight or curved in all cross-sections parallel to the main plane. For each of these cross-sections, a center line running midway between an inner surface and an outer surface of the flat element can be used to determine its course.
[0073] A continuously straight or curved profile may be present, in particular, if even in the most curved 0.015 mm long section of the center line there is no change in direction of 30° or more.
[0074] A continuously straight or curved profile can be advantageous if, even in the most curved 0.025 mm section of the centerline, there is no change in direction of 30° or more. A continuously straight or curved profile can be particularly advantageous if, even in the most curved 0.040 mm section of the centerline, there is no change in direction of 30° or more.
[0075] It can be advantageous if the frontal zone begins at an altitude 25% above the base level and simultaneously 75% below the maximum level, and ends at an altitude 50% above the base level and simultaneously 50% below the maximum level.
[0076] It can be particularly advantageous if the frontal zone begins at an altitude 20% above the base level and simultaneously 80% below the maximum level, and ends at an altitude 50% above the base level and simultaneously 50% below the maximum level.
[0077] It can be particularly advantageous if the frontal zone begins at an altitude 25% above the base level and simultaneously 75% below the maximum level, and ends at an altitude 55% above the base level and simultaneously 45% below the maximum level.
[0078] It can be particularly advantageous if the frontal zone begins at an altitude 20% above the base level and simultaneously 80% below the maximum level, and ends at an altitude 55% above the base level and simultaneously 45% below the maximum level.
[0079] It can be advantageous if, within the height transition section, the flat element runs continuously straight or curved in all cross-sections parallel to the main plane wherever it has an inclination of 30° or more. For each of these cross-sections, a center line running midway between an inner surface and an outer surface of the flat element is used to determine its course. A continuously straight or curved course exists if, even in the most curved 0.015 mm section of the center line, there is no change in direction of 30° or more. A continuously straight or curved course can also be advantageous if, even in the most curved 0.025 mm section of the center line, there is no change in direction of 30° or more.A continuously straight or curved profile can be particularly advantageous if, even in the most curved 0.040 mm long section of the center line, there is no change in direction of 30° or more.
[0080] Whether the flat element has an inclination of 30° or more with respect to a main plane can be determined in particular on the outer surface of the flat element.
[0081] It can be advantageous if the elevation in the transition zone slopes more gently in the longitudinal direction than perpendicular to the longitudinal direction in an extension zone adjoining the transition zone along the longitudinal direction.
[0082] This can mean, for example, that the elevation in the transition zone slopes more gently on average in the longitudinal direction than perpendicular to the longitudinal direction in an extension zone adjoining the transition zone along the longitudinal direction. The determining factor for whether the elevation in the transition zone slopes more gently on average in the longitudinal direction than perpendicular to the longitudinal direction in an extension zone adjoining the transition zone along the longitudinal direction can be the shortest path along the outer surface of the elevation.If the shortest path in the transition zone, running longitudinally across the entire transition zone down to the end of the elevation, is longer than the shortest path in the extension zone, running perpendicular to the longitudinal direction down to the base level of the elevation, then the elevation in the transition zone slopes more gently on average in the longitudinal direction than perpendicular to the longitudinal direction in an extension zone adjoining the transition zone along the longitudinal direction.
[0083] This can alternatively or additionally mean that the elevation in the elevation transition section slopes more gently in the longitudinal direction at the steepest longitudinally sloping point on the outer surface of the elevation than in the extension zone transversely to the longitudinal direction at the steepest transversely sloping point on the outer surface of the elevation. For example, the steepest longitudinally sloping point on the outer surface of the elevation may slope at a longitudinal angle to the main plane, and the steepest transversely sloping point on the outer surface of the elevation may slope at a transverse angle to the main plane.
[0084] Advantageously, the transverse slope angle can be at least 10°, preferably at least 15°, particularly preferably at least 20°, greater than the longitudinal slope angle.
[0085] It can be advantageous if the flow element is a bipolar plate element for an electrochemical system, e.g. for a fuel cell system or an electrolysis system.
[0086] It can be advantageous if the flow element, e.g. the bipolar plate element, has channels, including a first, a second and a third channel, with the elevation extending between the first and the second channel.
[0087] Advantageously, a fluid-conducting connection between the first and second channels can exist at the end of the rise.
[0088] The elevation can be a first elevation and the flat element can have a second elevation, with the second elevation extending between the second and third channels.
[0089] At the end of the second rise, a fluid-conducting connection exists between the second and third channels.
[0090] Advantageously, the end of the first rise can be offset from the end of the second rise with respect to the direction of the second channel, which runs between the first rise and the second rise.
[0091] Advantageously, a multitude of elevations, including in particular the first and second elevations, can define a support level. The highest levels of the elevations, e.g., the plateaus formed on the elevations, which the elevations may exhibit especially in their extension zones, can define the support level. A membrane electrode assembly (MEA), in particular a gas diffusion layer (GDL) of an MEA, can be located in the support level of a fuel cell system.
[0092] The maximum level can be located at the support level and / or be defined by the support level.
[0093] Advantageously, multiple channels, including the first, second, and third channels, can have multiple channel bottoms, and these channel bottoms can define a channel bottom plane. Any channel bottom elevations that channels may have are disregarded when defining the channel bottom plane.
[0094] It can be advantageous if the channel bottom plane is the plane parallel to or coinciding with the main plane, in which the deepest zones contain several channels of the flow element, e.g., the bipolar plate element, where the several channels can include, for example, the first, the second, and the third channel.
[0095] It is possible that the flat element in a transition zone from a channel to an elevation is not shaped in such a way that a recognizable transition from the channel to the elevation is evident. For example, starting from the lowest zone of a channel, the flat element may rise continuously, initially gently, then increasingly steeply, and subsequently gently again, up to the highest level of an elevation that borders the channel.
[0096] In particular, but not only then, it can be advantageous if the base level is defined by means of a base plane, wherein the base plane is a plane parallel to the canal bottom plane, the distance of which to the highest level is 50 times greater than to the canal bottom plane, and wherein the base level lies in the base plane.
[0097] It is advantageous for the base of the elevation to be located in the base plane.
[0098] The end of the elevation can be advantageously located at the base level. The highest level of the elevation can refer to a plateau formed at the very top of the elevation. The elevation may exhibit this plateau particularly in its extension zone.
[0099] Further preferred features and / or advantages of the invention are the subject of the following description and the graphic representation of exemplary embodiments.
[0100] They show:
[0101] Fig. 1: a section of a flow element with one end of a raised section in perspective view;
[0102] Fig. 2: a section of a flow element with one end of a raised section in perspective view;
[0103] Fig. 3: a section through the elevation from Fig. 2 along the line 13-13;
[0104] Fig. 4: a section through the elevation from Fig. 2 along the line IV-IV indicated in Fig. 3;
[0105] Fig. 5: a section of a flow element with one end of a raised section in perspective view;
[0106] Fig. 6: a section through the elevation from Fig. 5 along the line Vl-Vl;
[0107] Fig. 7: a section through the elevation from Fig. 5 along the line VI1-VII indicated in Fig. 6;
[0108] Fig. 8: a section of a flow element with one end of a raised section in perspective view;
[0109] Fig. 9: a section through the elevation from Fig. 8 along line IX-IX; Fig. 10: a section through the elevation from Fig. 8 along line XX indicated in Fig. 9;
[0110] Fig. 11: a section of a flow element with one end of a raised section in perspective view;
[0111] Fig. 12: a section through the elevation from Fig. 11 along line X1-X1;
[0112] Fig. 13: a section through the elevation from Fig. 11 along the line XIII-XIII indicated in Fig. 12;
[0113] Fig. 14: a section of a flow element with one end of a raised section in perspective view;
[0114] Fig. 15: a section through the elevation from Fig. 14 along line XV-XV;
[0115] Fig. 16: a section through the elevation from Fig. 14 along the line XVI-XVI indicated in Fig. 15;
[0116] Fig. 17: a section of a flow element with one end of a raised section in perspective view;
[0117] Fig. 18: a section through the elevation from Fig. 17 along line XVIII-XVIII;
[0118] Fig. 19: a section through the elevation from Fig. 17 along the line XIX-XIX indicated in Fig. 18;
[0119] Fig. 20: a section of a flow element with one end of a raised section in perspective view;
[0120] Fig. 21: a section through the elevation from Fig. 20 along line XXI-XXI;
[0121] Fig. 22: a section through the elevation from Fig. 20 along the line XXI I-XXII indicated in Fig. 21; Fig. 23: a flow element present as a bipolar plate element and / or separator plate element;
[0122] Fig. 24: a perspective view of the elevation from Fig. 8 with the frontal zone indicated;
[0123] Fig. 25: another representation of the elevation from Fig. 8 with the frontal zone indicated;
[0124] Fig. 26: a cross-section through the elevation from Figs. 8, 24 and 25 at the lower end of the frontal zone;
[0125] Fig. 27: a cross-section through the elevation from Figs. 8, 24 and 25 at the upper end of the frontal zone; and
[0126] Figs. 28-34: Excerpts from Figs. 4, 7, 10, 13, 16, 19 and 22, with circles additionally drawn for a more precise definition of approximately semicircular contours.
[0127] Identical or functionally equivalent elements are designated with the same reference symbols in all figures.
[0128] Fig. 1 shows a section of a flow element 100. The flow element 100 has a flat element 102. The flat element 102 is a sheet metal forming product 104.
[0129] The flat element 102 has a raised section 106.
[0130] The elevation 106 limits channels 108 of the flow element 100 on each side of the channels 108.
[0131] The elevation rises in a vertical direction 110 orthogonal to two principal extension directions 112 and 114 of the flat element 102, starting from a base level 116 at the foot 118 of the elevation 106 to a maximum level 120 of the elevation 106. The elevation 106 extends in a longitudinal direction 122 substantially parallel to a principal plane 124 defined by the two principal extension directions 112 and 114 of the flat element 102 to an end 126 of the elevation 106.
[0132] The principal plane 124 is indicated in Fig. 1 by dotted lines that intersect the two principal extension directions 112 and 114.
[0133] Fig. 2 also shows a section of the flow element 100, which is also shown in part in Fig. 1.
[0134] The flow element 100 shown in partial view in Figs. 1 and 2 is referred to below as a first flow element 100.
[0135] Fig. 5 shows a section of a second flow element 100.
[0136] Fig. 8 shows a section of a third flow element 100.
[0137] Fig. 11 shows a section of a fourth flow element 100.
[0138] Fig. 14 shows a section of a fifth flow element 100.
[0139] Fig. 17 shows a section of a sixth flow element 100.
[0140] Fig. 20 shows a section of a seventh flow element 100.
[0141] The flow elements 100 mentioned can be, in particular, bipolar plate elements 128 and / or separator plate elements 130. A flow element 100 that is a bipolar plate element 128 and / or a separator plate element 130 is shown in Fig. 23.
[0142] Fig. 23 clearly shows that the sections shown in Figs. 1, 2, 5, 8, 11, 14, 17 and 20 can be very small sections of the flow element 100 shown therein. For example, the elevations 106 shown therein on a flow element 100 can extend to a reaction zone end 132, in which a reaction zone 134 of the flow element 100 transitions into an operating fluid distribution structure 136 or into an operating fluid collection structure 138.
[0143] Fig. 23 shows a schematically represented, greatly enlarged section at a reaction zone end 132, in which contours of elevations 106 are indicated by way of example.
[0144] Fig. 23 makes it clear that it can be advantageous if the flat element has, in addition to the elevation 106 shown in the respective section, a plurality of further elevations 106 which are not shown in the respective sections of Figs. 1, 2, 5, 8, 11, 14, 17 and 20.
[0145] The section shown in Fig. 3 reveals that the elevation 106 has a transition zone 140, in which the height 144 of the elevation 106, measurable in the vertical direction 110, decreases in a height transition section 142 of the transition zone 140. Fig. 3 shows that the height 144 decreases in the height transition section 142 of the transition zone 140 until the height 144 of the elevation 106 is reduced to zero at the end 126.
[0146] In a latitudinal transition section 146 of the transition zone 140, a width 150 of the elevation 106 changes. The width 150 is measured in a latitudinal direction 148. The latitudinal direction 148 runs parallel to the main plane 124 and orthogonal to the longitudinal direction 122 in the base level 116. This is shown in Fig. 4. The section shown therein runs in the base level 116.
[0147] The other elevations 106 shown in Figs. 5 to 22 also each have a transition zone 140, wherein in a height transition section 142 of the transition zone 140 a height 144 of the elevation (106?) decreases and in a width transition section 146 of the respective transition zone 140 a width 150 of the elevation 106 changes.
[0148] In all the elevations 106 shown in Figs. 1 to 22, as the elevation 106 is approached the end 126 of the respective elevation 106, the cross-section of the elevation 106, which can be generated orthogonally to the respective longitudinal direction 122, begins to change along the longitudinal direction 122 of the respective elevation 106 as it gets closer to the beginning of the transition zone 140.
[0149] For the elevations 106 shown in Figures 1 to 22, height transition lengths 152 and width transition lengths 154 are specified in various figures. The height transition length is defined as the length of the height transition section 142 measurable in the longitudinal direction 122. The width transition length 154 is defined as the length of the width transition section 146 measurable in the longitudinal direction 122.
[0150] In all the elevations 106 shown in Figs. 1 to 22, a height transition length 152, which is a length of the height transition section 142 measurable in the longitudinal direction 122, is greater or less than a width transition length 154, which is a length of the width transition section 146 measurable in the longitudinal direction 122.
[0151] For the elevations 106 shown in Figures 1 to 16, the vertical transition length is greater than the horizontal transition length. For these elevations (the elevations 106 in Figures 1 to 7?), the vertical transition length is significantly more than 115% of the horizontal transition length. For the elevations shown in Figures 8 to 16, the vertical transition length is significantly more than 180% of the horizontal transition length.
[0152] In the elevations shown in Figures 17 to 22, the vertical transition length 152 is in each case smaller than the horizontal transition length 154. The horizontal transition length 154 is in each case significantly more than 180% of the vertical transition length.
[0153] For all the elevations 106 shown in Figs. 1-22, a length ratio calculated by dividing the height transition length 152 by the width transition length 154 is at least 1.3 or at most 0.8.
[0154] For example, the length ratio, calculated by dividing the height transition length 152 by the width transition length 154, is at least 1.3 for the elevations 106 shown in Figures 1 to 16, and at least 1.8 for the elevations 106 shown in Figures 8 to 16. For example, a length ratio, calculated by dividing the height transition length 152 by the width transition length 154, is less than 0.6 but more than 0.1 for the elevations 106 shown in Figures 17 to 22.
[0155] In the elevations 106 shown in Figures 17 to 22, the width transition sections 146 each have a width expansion section 156. In the width expansion section 156 of the width transition section 146, the width 150 of the elevation 106 increases with increasing proximity to the end 126 of the elevation 106.
[0156] Figures 17 to 19 show an example of an elevation 106, wherein in the width extension section 156 of the width transition section 146 the elevation 106 is extended on both sides.
[0157] Figures 20 to 22 show an example of an elevation 106, wherein in the width extension section 156 of the width transition section 146 the elevation 106 is extended on one side.
[0158] In the flow elements 100 shown in Figures 1 to 23, the flat element 102 runs continuously in a straight or curved line within the height transition section 142 in a frontal zone in all cross-sections parallel to the main plane 124. The frontal zone 158 begins at a height 25% above the base level 116 and simultaneously 75% below the maximum level 120. The frontal zone ends at a height 50% above the base level 116 and simultaneously 50% below the maximum level 120.
[0159] Fig. 24 illustrates the course of the frontal zone 158 by way of example at the elevation 106 shown in Figs. 8 to 10. The frontal zone 158 is also shown in Fig. 25, which likewise shows an elevation 106 as depicted in Figs. 8 to 10.
[0160] For each of the cross-sections mentioned in connection with the frontal zone 158, a center line 164 running in the middle between an inner surface 160 of the flat element 102 and an outer surface 162 of the flat element 102 can be used to determine the course of the flat element 102, wherein the continuously straight or curved course is present if even in a most strongly curved 0.015 mm long section of the center line 164 there is no change in direction of 30° or more.
[0161] This is illustrated in Fig. 26 for a cross-section located at the lower end of the frontal zone 158 and in Fig. 27 for a cross-section located at the upper end of the frontal zone 158. The center line 164, which runs centrally between the inner surface 160 and the outer surface 162 in the respective cross-section, is indicated by a dotted line.
[0162] Figures 9 and 10 show, by way of example, the flow element 100 depicted therein, which at an end 168 of the lateral transition section 146 located in the longitudinal direction 122 from the end 126 of the elevation 106, the residual height 166 of the elevation 106, measurable from the base level 116, can be significantly less than 95% of the distance from the base level 116 to the maximum level 120.
[0163] Figures 9 and 24 clearly show that the elevation 106 in the elevation transition section 142 slopes more gently in the longitudinal direction 122 than transversely to the longitudinal direction 122 in an extension zone 170 adjoining the transition zone.
[0164] Figures 28 to 34 show details of Figures 4, 7, 10, 13, 16, 19, and 22. These figures show that in all the elevations 106 shown in the figures, the width transition section 146 has a width reduction section in which the width 150 of the elevation 106 decreases in an approximately semicircular shape as it approaches the end of the elevation. At its respective base 118, each elevation 106 lies entirely between two concentric circles of different sizes in the base level 116, the diameter of the smaller circle being more than 67% of the diameter of the larger circle in all elevations.
[0165] The elevations shown in the figures do not refer to a base plane as described herein. This is because each figure clearly shows a distinct transition from the channel to the elevation.
[0166] However, the figures represent ideally formed elevations. The edges and transitions shown in them often do not occur with the depicted precision in actual embossed elevations, so that to define the base level and the features relating to it in actual embossed elevations, one could refer back to a base plane, for example as described here.
[0167] Reference symbol list
[0168] Flow element flat element
[0169] Sheet metal forming product increase
[0170] channel
[0171] Altitude
[0172] Main extension direction Main extension direction Base level
[0173] Foot
[0174] top level
[0175] Longitudinal direction main plane end
[0176] Bipolar plate element, separator plate element, reaction zone end, reaction zone
[0177] Operating fluid distribution structure, operating fluid collection structure, transition zone
[0178] High-altitude transition section
[0179] Latitude transition section, latitude direction
[0180] Width
[0181] Altitude transition length, latitude transition length, latitude expansion section, frontal zone
[0182] Inner surface Outer surface
[0183] Center line, residual height, end of extension zone
Claims
Patent claims 1. Flow element (100) comprising a flat element (102), wherein the flat element (102) may be, for example, a sheet metal forming product (104), wherein the flat element (102) has a raised section (106), wherein it may be advantageous if the raised section (106) is, for example,a channel (108) of the flow element (100) bounded at least one side of the channel (108), the elevation (106) rising in a vertical direction (110) orthogonal to two principal extension directions (112, 114) of the flat element (102) from a base level (116), in particular at the base (118) of the elevation (106), to a maximum level (120) of the elevation (106), the elevation (106) extending in a longitudinal direction (122) substantially parallel to a principal plane (124) defined by the two principal extension directions (112, 114) of the flat element (102) or in a principal plane (124) defined by the two principal extension directions (112, 114) of the flat element (102) to an end (126) of the elevation (106), and the elevation (106) has a transition zone (140) wherein in a height transition section (142) of the transition zone (140) a height (144) of the elevation (106) decreases, e.g.until the height (144) of the elevation (106) has decreased to zero at the end (126), wherein the height (144) of the elevation (106) is taken in the vertical direction (110), and / or in a latitudinal transition section (146) of the transition zone (140) a width (150) of the elevation (106) changes, e.g. until the width (150) of the elevation (106) has decreased to zero at the end (126), wherein the width (150) of the elevation (106) is taken in a latitudinal direction (148) that is parallel to the main plane (124) and orthogonal to the longitudinal direction (122) in the base level (116).
2. Flow element (100) according to claim 1, characterized in that the width transition section (146) has a width reduction section in which the width of the elevation decreases in an approximately semicircular manner with increasing proximity to the end of the elevation, wherein an approximately semicircular reduction is present when the elevation (106) at the base (118) of the elevation (106) runs completely between two concentric circles of different sizes lying in the base level (116) throughout the entire width reduction section, wherein the diameter of the smaller circle is at least 67% of the diameter of the larger circle.
3. Flow element (100) according to claim 1 or 2, characterized in that in the height transition section (142) the height (144) of the elevation (106) decreases until the height (144) of the elevation (106) has decreased to zero at the end (126), and in the width transition section (146) the width (150) of the elevation (106) changes until the width (150) of the elevation (106) has decreased to zero at the end (126).
4. Flow element (100) according to one of the preceding claims, characterized in that a height transition length (152), which is a length of the height transition section (142) taken in the longitudinal direction (122), is greater or less than a width transition length (154), which is a length of the width transition section (146) taken in the longitudinal direction (122).
5. Flow element (100) according to claim 4, characterized in that one of the two transition lengths, namely the height transition length (152) or the width transition length (154), is at least 115%, e.g. at least 180%, of the other of the two transition lengths, namely the altitude transition length (152) or the latitude transition length (154).
6. Flow element (100) according to claim 4 or 5, characterized in that a length ratio, calculated by dividing the height transition length (152) by the width transition length (154), is at least 1.3 or at most 0.
8.
7. Flow element (100) according to one of claims 4 to 6, characterized in that a length ratio, which is calculated by dividing the height transition length (152) by the width transition length (154), is at least 1.8 or at most 0.
6.
8. Flow element (100) according to claim 6 or 7, characterized in that the length ratio, if it is at least 1.3 or at least 1.8, is at most 7, or the length ratio, if it is at most 0.8 or at most 0.6, is at least 0.
1.
9. Flow element (100) according to one of the preceding claims, characterized in that in a width expansion section (156) of the width transition section (146) the width (150) of the elevation (106) increases with increasing proximity to the end (126) of the elevation (106).
10. Flow element (100) according to claim 9, characterized in that in the width expansion section (156) of the width transition section (146) the elevation (106) is expanded on both sides.
11. Flow element (100) according to claim 9, characterized in that in the width expansion section (156) of the width transition section (146) the elevation (106) is expanded on one side or is expanded more on one side of the elevation (106) than on the other side of the elevation (106).
12. Flow element (100) according to one of the preceding claims, characterized in that at an end (168) of the width transition section (146) located in the longitudinal direction (122) from the end (126) of the elevation (106) a residual height (166) of the elevation (106) taken from the base level (116) is at most 95%, e.g. at most 75%, of a distance from the base level (116) to the maximum level (120).
13. Flow element (100) according to one of the preceding claims, characterized in that the flat element (102) within the height transition section (142) in a frontal zone (158) which begins at a height (144) 25% above the base level (116) and simultaneously 75% below the maximum level (120) and ends at a height (144) 50% above the base level (116) and simultaneously 50% below the maximum level (120), runs continuously straight or curved in all cross-sections parallel to the main plane (124), wherein for each of these cross-sections, a center line (164) running centrally between an inner surface (160) of the flat element (102) and an outer surface (162) of the flat element (102) is used to determine the course of the flat element (102), wherein the continuously straight or A curved path exists if even in the most strongly curved 0,No change of direction of 30° or more occurs in the 015 mm long section of the center line (164).
14. Flow element (100) according to one of the preceding claims, characterized in that the flat element (102) within the height transition section (142) wherever the flat element (102) has an inclination relative to the main plane (124). exhibits a curvature of 30° or more, and in all cross-sections parallel to the main plane (124) is continuously straight or curved, wherein for each of these cross-sections a center line (164) running centrally between an inner surface (160) of the flat element (102) and an outer surface (162) of the flat element (102) is used to determine the course of the flat element (102), wherein the continuous straight or curved course is present if even in the most strongly curved 0.015 mm long section of the center line (164) there is no change in direction of 30° or more.
15. Flow element (100) according to one of the preceding claims, characterized in that the elevation (106) in the height transition section (142) slopes more gently in the longitudinal direction (122) than transversely to the longitudinal direction (122) in an extension zone (170) adjoining the transition zone (140) along the longitudinal direction (122).
16. Flow element (100) according to one of the preceding claims, characterized in that the flow element (100) is a bipolar plate element (128) for an electrochemical system, e.g. for a fuel cell system or an electrolysis system.
Citation Information
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