Flow guide plate for an electrochemical cell and plate stack with a plurality of such flow guide plates

Abstract

Flow guide plate (1) for an electrochemical cell (3), comprising at least one planar flow guide area (5) having a center (7) and a periphery (9), wherein at least one flow guide (11) is arranged in the flow guide area (5), which fluidically connects a media inlet (13) with a media outlet (15), wherein a) a first flow guide section (17) of the flow guide (11) leads from the media inlet (13) arranged in the periphery (9) to the center (7) and transitions in the center (7) into a second flow guide section (19) of the flow guide (11), which leads from the center (7) back to the media outlet (15) also arranged in the periphery (9), or b) the first flow guide section (17) leads from the media inlet (13) arranged in the center (7) to the periphery (9) and in the periphery (9) transitions into the second flow guidance section (19),which leads from the periphery (9) back to the media outlet (15) also arranged in the center (7), wherein the first flow guidance section (17) and the second flow guidance section (19) run parallel to each other, characterized in that the flow guidance plate (1) has, in addition to the at least one media inlet (13) and the at least one media outlet (15) for a medium, at least one passage opening (23) for the same medium, wherein the passage opening (23) for the same medium is not fluidically connected to the flow guidance area (5), wherein the at least one passage opening (23) and the at least one media inlet (13) and / or the at least one media outlet (15) have the same cross-sectional size and shape, wherein the flow guidance plate (1) is designed in such a way thatthat, starting from a first position of the flow guide plate (1) in space, after a rotation of the flow guide plate (1) by a certain angle, the passage opening (23) in a second position of the flow guide plate (1) in space comes to be located at a first location where a functional opening, selected from the media inlet (13) and the media outlet (15), is arranged in the first position, and the functional opening in the second position comes to be located at a second location where the passage opening (23) is arranged in the first position.

Description

[0001] The invention relates to a flow guide plate for an electrochemical cell and to a stack of plates of an electrochemical cell with such a flow guide plate.

[0002] Such a flow-guiding plate has a planar flow-guiding area in which a flow guide is arranged that fluidically connects a media inlet to a media outlet. The flow guide is intended to distribute a fluid medium, particularly a gaseous or liquid medium, especially a coolant or a reaction medium, which participates in an electrochemical reaction in an electrochemical cell in which the flow-guiding plate is used, as uniformly as possible across the flow-guiding area and ultimately across the surface of the flow-guiding plate. The distribution of the reaction medium across the flow-guiding plate should be as uniform as possible with respect to both media pressure and media concentration in order to achieve the highest possible efficiency and performance for the electrochemical cell.In particular, energy flows across the surface of the flow guide plate should be designed to be as uniform as possible.

[0003] Typical flow paths run – possibly with multiple deflections of up to 180° – essentially diagonally across the flow guide plate, with the media inlet and outlet located opposite each other along a plate diagonal. This typically results in a significant pressure and concentration drop diagonally across the flow guide plate between the media inlet and outlet, which is detrimental to the efficiency and effectiveness of an electrochemical cell incorporating the flow guide plate.

[0004] The invention is based on the objective of providing a flow guide plate for an electrochemical cell and a stack of plates with a plurality of such flow guide plates, wherein the aforementioned disadvantages are reduced, preferably do not occur.

[0005] The problem is solved by providing the present technical teaching, in particular the teaching of the independent claims as well as the embodiments disclosed in the dependent claims and the description.

[0006] The problem is solved in particular by providing a flow-guiding plate in which a first flow-guiding section leads from the media inlet, located at the periphery of the flow-guiding area, to a center of the flow-guiding area, wherein the first flow-guiding section transitions into a second flow-guiding section at the center, the second flow-guiding section leading from the center back to the media outlet, also located at the periphery of the flow-guiding area. Alternatively, the first flow-guiding section leads from the media inlet located at the center to the periphery and transitions at the periphery into the second flow-guiding section, which leads from the periphery back to the center and to the media outlet, also located at the center.The media outlet and the media inlet are both located either at the periphery or at the center of the flow guidance area. The flow path runs from the media inlet to the media outlet either from the periphery into the center and back to the periphery, or from the center into the periphery and back to the center. A flow reversal occurs where the first flow guidance section transitions into the second, so that the medium flows back against the flow direction in the first flow guidance section to the media outlet located in the same area as the media inlet. The first and second flow guidance sections run parallel to each other.This method is particularly advantageous because it achieves a very uniform pressure and concentration distribution across the flow guidance area. Specifically, the flow guidance area incorporates zones of high and low pressure, as well as high and low concentration, both centrally and peripherally, resulting in an average pressure and concentration level across the entire flow guidance area. Consequently, this provides exceptionally high efficiency for an electrochemical cell incorporating the flow guidance plate.

[0007] An electrochemical cell is understood here to be, in particular, a device in which a medium undergoes an electrochemical reaction, either to generate electrical power through the electrochemical reaction of the medium or to obtain at least one specific product from the electrochemical reaction by applying electrical power. The electrochemical cell preferably comprises a plurality of galvanic cells that are electrically interconnected. The electrochemical cell can, in particular, be configured as a fuel cell: In this case, a reactant medium is electrochemically reacted with an oxidizing agent to form a product medium, in particular by oxidation, thereby generating electrical power. Hydrogen, methane, methanol, or another suitable reactant medium can, in particular, be used.The electrochemical cell can also be designed as an electrolysis cell, in which a reactant medium is electrochemically split into at least two product media by applying electrical power. In particular, water can be used as the reactant medium and split into hydrogen and oxygen. The electrochemical cell can be designed, in particular, as a fuel cell with a proton exchange membrane (PEM), especially with a polymer electrolyte membrane, or as a ceramic fuel cell, especially as a solid oxide fuel cell (SOFC), or in another suitable manner.

[0008] The flow guide plate is preferably a bipolar plate, a subplate of a bipolar plate (particularly one consisting of two subplates), or a monopole plate for the electrochemical cell. In this respect, the flow guide plate serves in particular to spatially define a galvanic cell within the electrochemical cell and preferably also to electrically connect adjacent galvanic cells. A bipolar plate can, in particular, be composed of two adjacent subplates, wherein one subplate of the bipolar plate can have a first flow guide area on a side facing a galvanic cell for guiding a reaction medium and a second flow guide area on a side facing the other subplate of the bipolar plate for guiding a coolant.In this case, it is possible that the coolant is guided between the sub-plates of a bipolar plate composed of two sub-plates.

[0009] The center of the flow guidance area is in particular a central area of ​​the flow guidance area, wherein the periphery is a peripheral area surrounding the center.

[0010] A galvanic cell of the electrochemical cell is specifically delimited by two flow guide plates, between which an electrolyte unit is arranged, for example, a proton exchange membrane or, in particular, a ceramic solid electrolyte. The electrolyte unit separates the two half-cells of the galvanic cell from each other. A gas diffusion layer is preferably arranged between the electrolyte unit and the two flow guide plates, which contributes to a better distribution of the reaction media across the electrolyte unit. In the case of a fuel cell, the reactant medium, for example, hydrogen, methane, or methanol, is supplied to one half-cell via the flow guide plate, while the oxidizing agent, in particular air or oxygen, is supplied to the other half-cell via the flow guide plate.The electrochemical reaction is effected by protons passing through the electrolyte system and thus migrating between the half-cells. Electron transport occurs via an electrical connection between the half-cells, particularly via the flow guide plates, which themselves can be electrically conductive, or via the electrolyte system, which is preferably coated accordingly. In the case of the fuel cell, the product medium, namely water, accumulates, in particular, in the cathodic half-cell, to which the flow guide plate is assigned, which carries the oxidizing agent. The product medium is then also discharged via this plate.

[0011] The flow guide is preferably recessed into the flow guide plate, in particular by forming, especially embossing, or by machining, especially milling. In particular, the flow guide is preferably designed as a groove.

[0012] The media inlet and outlet are preferably designed as openings in the flow guide plate, which are also referred to as functional openings in the following. These functional openings are then connected to the flow guide in a fluid-technical manner.

[0013] It is possible that the flow guide plate has further openings. In particular, the flow guide plate can additionally have at least one through-opening through which a medium can pass, whereby the through-opening is not fluidically connected to a flow guide. For example, such a through-opening can serve to convey coolant, or to convey a reaction medium that is not introduced into a flow guide of the flow guide plate but is, for example, directed to another flow guide plate.

[0014] Additionally or alternatively, the flow guide plate can have at least one mounting opening and / or at least one alignment opening, wherein the mounting and / or alignment opening can serve to align a plurality of flow guide plates relative to each other and to assemble them into a stack of plates. In particular, it is then possible to arrange a plurality of flow guide plates one behind the other with alignment openings aligned with each other.

[0015] According to a further development of the invention, the first flow guidance section and the second flow guidance section are arranged to run directly adjacent to each other. This means, in particular, that the first flow guidance section and the second flow guidance section run side by side, so that, in particular, a region of the second flow guidance section is always located next to a region of the first flow guidance section. However, it is possible that the first flow guidance section and the second flow guidance section do not run directly adjacent to each other in outlet regions where the media inlet flows into the first flow guidance section and where the second flow guidance section flows into the media outlet.In particular, the first flow guidance section and the second flow guidance section run directly adjacent to each other, especially alongside each other, except at the outlet areas. This has the advantage that areas of the flow guidance with high pressure and high concentration are always adjacent to those with low pressure and low concentration, so that a constant average value of pressure and concentration, and preferably also of the medium temperature, is achieved, especially across the area of ​​the flow guidance section. This contributes significantly to efficient operation and a high efficiency of the electrochemical cell.

[0016] According to a further development of the invention, at least one flow guidance section, selected from the first flow guidance section and the second flow guidance section, has a cumulative deflection of more than 180° along its length. Preferably, both the first flow guidance section and the second flow guidance section each have a cumulative deflection of more than 180° along their length. A cumulative deflection is understood in particular to be the sum of the deflection angles that the fluid flow experiences along the flow guidance in the considered flow guidance section. Deflections with the same direction of deflection, for example, to the right in the flow direction, are considered with the same sign, and deflections with the opposite direction of deflection, for example, to the left in the flow direction, are considered with opposite signs.Particularly preferably, the at least one flow-guiding section, selected from the first and second flow-guiding sections, has a cumulative deflection of at least 360° along its length. Preferably, the first and second flow-guiding sections together have cumulative deflections of at least 2 times 360° along their length, optionally with alternating directions of deflection between the cumulative deflections, particularly between the first and second flow-guiding sections. Such high cumulative deflections allow for a particularly suitable nested flow path, which contributes to a high degree of homogeneity in the distribution of pressure, concentration, and preferably also temperature of the medium across the flow-guiding area.

[0017] According to a further development of the invention, the at least one flow guide is designed in a spiral shape. In particular, the first flow guide section and the second flow guide section preferably run parallel to each other, i.e., side by side, along an imaginary spiral line or along an imaginary spiral. In other words, a double spiral is preferably formed by the two flow guide sections, each running spirally parallel to each other and fluidically connected, namely the first flow guide section and the second flow guide section. The spiral shape of the at least one flow guide enables a particularly favorable homogeneous distribution, especially of pressure, concentration, and / or temperature of a medium, across the flow guide area.

[0018] The fact that at least one flow guide is spirally shaped means, in particular, that it has the form of a spiral. This can be a curved spiral, for example, an Archimedean spiral or a spiral composed of circular arcs. A curved spiral shape has the advantage that no corners occur, thus avoiding undesirably high back pressures in the corner region and, in particular, a high pressure loss along the flow guide. This specifically reduces the pressure loss between the media inlet and outlet. Alternatively, it can be an angular spiral, in particular a spiral composed of segments. This represents a particularly simple geometry to manufacture. Most preferably, the at least one flow guide has the form of a spiral composed of segments, with intersecting segments preferably being arranged in pairs perpendicular to each other.

[0019] In particular, the media inflow and the media outflow are both arranged either - according to a first design - in the periphery, i.e. at the edge of the spiral, or - according to a second design - in the center of the spiral.

[0020] According to a further development of the invention, the at least one flow guidance area comprises a plurality of flow guides; thus, in this case, the at least one flow guide is a plurality of flow guides. The flow guides of the flow guidance area are preferably arranged nested within one another. With a plurality of flow guides per flow guidance area, and in particular with the nesting of the different flow guides, a particularly uniform distribution, especially of pressure, temperature, and / or concentration of the medium, can be achieved across the flow guidance area.

[0021] Particularly preferred are multiple helical flow guides nested within one another, especially by each outer helical flow guide surrounding an inner helical flow guide. By nesting the various flow guides, first and second flow guide sections are arranged alternately, so that average values ​​for temperature, pressure, and / or concentration of the medium are effectively established over the entire flow range.

[0022] Preferably, at least two of the flow paths are assigned a common media inlet. Alternatively or additionally, at least two of the flow paths are assigned a common media outlet. It is possible that all flow paths are assigned a common media inlet, while each flow path may also have a separate media outlet, or at least two flow paths may share a common media outlet. It is also possible that all flow paths are assigned a common media outlet, while each flow path may have a separate media inlet, or at least two flow paths may share a common media inlet. It is also possible that all flow paths within the flow path area are assigned both a common media inlet and a common media outlet.It is also possible that each flow path has both a separate media inlet and a separate media outlet.

[0023] According to a further development of the invention, the cross-section of at least one flow guide decreases in the flow direction from the media inlet to the media outlet. This advantageously allows, in particular, a pressure loss between the media inlet and the media outlet to be at least partially compensated or at least reduced. The cross-section of the flow guide is, in particular, the open passage cross-section for the medium flowing in the flow guide. This cross-section can be reduced in various ways: Preferably, at least one geometric dimension of the flow guide decreases along its path from the media inlet to the media outlet. In particular, it is possible for the width of a groove forming the flow guide to decrease from the media inlet to the media outlet; alternatively or additionally, the depth of the groove can decrease from the media inlet to the media outlet.

[0024] According to a further development of the invention, the at least one flow guide comprises exactly one flow channel. This represents a particularly simple embodiment of the flow guide. Such a flow channel is, in particular, a recess in the flow guide plate, especially a groove. Alternatively, it is possible for the at least one flow guide to have a plurality of flow channels, wherein the flow channels of the same flow guide are fluidically connected to the same media inlet and the same media outlet. Thus, starting from the media inlet, the flow guide branches into the various flow channels, all of which empty into the same media outlet. Preferably, they are brought together upstream of the media outlet and merged to form a single flow channel that empties into the media outlet.A higher number of finer partial flow channels is advantageously achieved when the flow path has multiple flow channels. This allows for better support of a solid electrolyte, such as a membrane. Furthermore, a more uniform ion distribution within the solid electrolyte is advantageously achieved, which reduces overvoltages and efficiency losses.

[0025] According to a further development of the invention, the flow guide plate is provided to have a plurality of flow guide areas. In this respect, the at least one flow guide area is thus a plurality of flow guide areas. This has the advantage over a single, large flow guide area on the flow guide plate that it is not necessary to arrange a single pair or a few pairs of media inlets and outlets closely next to each other in a specific area of ​​the flow guide plate, but rather that a plurality of media inlets and outlets can be distributed over the flow guide plate. This facilitates the connection of the media inlets and outlets to the end plates of a stack of plates comprising the flow guide plate.The flow-guiding areas of a flow-guiding plate are preferably arranged side by side or one above the other on the plate, particularly along Cartesian coordinates that define a Cartesian coordinate system on the flow-guiding plate. The coordinate axes are preferably oriented parallel to the edges of the flow-guiding plate. Reference will be made to these Cartesian coordinates in the following sections.

[0026] According to a further development of the invention, the media inlet and outlet of the at least one flow guide are arranged side by side. This has the advantage of a particularly space-saving configuration. In particular, the media inlet and outlet are preferably arranged directly adjacent to each other. Preferably, the media inlet and outlet are arranged on the same side, and especially on the same side, of the flow guide area. A side of the flow guide area is, in particular, the area around an imaginary boundary edge or next to an imaginary boundary edge of the flow guide area, especially in a top view of the flow guide area, to the right, left, top, bottom, or in a corner.

[0027] Alternatively, the media inlet and outlet of the at least one flow guide are preferably arranged on different sides of the flow guide area. This also results in a spatial separation of the respective connections, which are therefore easier to install. In particular, the media inlet and outlet can be arranged opposite each other along one of the Cartesian coordinates of the flow guide plate, or diagonally opposite each other above the flow guide area.

[0028] According to a further development of the invention, the flow guidance plate is provided to have a plurality of flow guidance areas. In this case, the at least one flow guidance area is therefore a plurality of flow guidance areas. Each flow guidance area is assigned at least one media inlet and at least one media outlet, wherein, along at least one Cartesian direction on the flow guidance plate, preferably along both Cartesian directions, a media outlet is arranged between each pair of media inlets. Alternatively or additionally, a media inlet is arranged between each pair of media outlets. This configuration has the advantage that the media inlets and media outlets are arranged alternately along the respective Cartesian direction.The media outlets and media inlets are therefore not located directly next to each other; that is, preferably no two media outlets are arranged immediately adjacent to each other, and preferably no two media inlets are arranged immediately adjacent to each other. Instead, media inlets and outlets preferably alternate. This configuration also contributes to achieving the most uniform distribution possible, particularly of pressure, concentration, and / or temperature, across the flow guide plate.

[0029] According to a further development of the invention, the flow guide plate, in addition to the at least one media inlet and the at least one media outlet, has at least one through-opening for the same medium. Thus, besides the functional openings, namely the media inlet and outlet, the flow guide plate has at least one through-opening for the medium, which is in particular selected from a reaction medium and a cooling medium. Such a through-opening has no fluidic connection to a flow guide area on the flow guide plate. While a functional opening is fluidic connected to a flow guide area, a through-opening has no such connection and serves only to allow a medium to pass through the flow guide plate, in particular to another flow guide plate.This has the advantage that not all flow guide plates in a plate stack need to be supplied by the same media inlets and outlets. Otherwise, especially with a large plate stack, this could lead to the last flow guide plates being supplied with insufficient pressure and / or concentration. Using the design described here, it is possible to supply the medium to a specific flow guide plate via at least one media inlet, and simultaneously supply the medium to another flow guide plate via the through-opening, thus creating separate flow channels for separate flow guide plates.

[0030] According to a further development of the invention, it is provided that the at least one passage opening and the at least one media inlet and / or the at least one media outlet have the same cross-sectional size and cross-sectional shape, wherein the flow guide plate is designed such that - starting from a first position of the flow guide plate in space - after a rotation of the flow guide plate by a certain angle, in particular by 90° or by 180°, the passage opening in a second position of the flow guide plate in space comes to be located at a first location where a functional opening, selected from the media inlet and the media outlet, is arranged in the first position, wherein the functional opening in the second position comes to be located at a second location where the passage opening in the first position is arranged.This allows for the alternating feeding of flow guide plates from different flow channels by using the same flow guide plate multiple times, but rotating it in a specific sequence with respect to its angular position, particularly by 90° or alternately by 180°. In the first layer of a flow guide plate, for example, its media inlet aligns with a first flow channel, while the opening aligns with a second flow channel. In the second layer, rotated by, for example, 180°, the opening of another flow guide plate aligns with the first flow channel, and its media inlet with the second flow channel. Thus, identical parts can be used for a stack of plates, and yet different flow guide plates can be fed from different flow channels.The fact that the flow guide plate is designed in this way means, in particular, that the through-opening, as well as the media inlet and outlet, are arranged on the flow guide plate in such a way as to result in the corresponding rotational property or symmetry. The rotation through the specified angle is preferably provided about a Cartesian axis that is either perpendicular to the flow guide plate or corresponds to one of the Cartesian directions of the flow guide plate. In particular, this is preferably a shorter axis of the flow guide plate, especially a vertical direction of the flow guide plate. Depending on the design or geometry of the flow guide plate, virtually any angle is possible, but integer divisors of 360° are particularly preferred, especially 90° for, for example, square plates, or 60° for hexagonal plates, or 45° for octagonal plates, etc.Circular flow guide plates are also possible, and in this case, even non-integer dividers of 360° are possible.

[0031] The problem is also solved by creating a stack of plates of an electrochemical cell comprising a plurality of flow-guiding plates according to the invention or flow-guiding plates according to one of the previously described embodiments. Each flow-guiding plate of the plurality of flow-guiding plates has functional openings in the form of at least one media inlet and at least one media outlet, as well as at least one through-opening that is not fluidically connected to a flow-guiding area. These openings of the flow-guiding plates are aligned with one another along a stacking direction of the plate stack, with the various mutually aligned openings each forming a flow channel for a medium along the stacking direction.This advantageously creates different flow channels, whereby different flow guide plates can be supplied via their respective media inlets from different flow channels.

[0032] In particular, the openings of adjacent flow guide plates are aligned with each other, especially in pairs. It is possible that functional openings and passage openings alternate along a flow channel. However, it is also possible that a different, especially grouped or loosely arranged, sequence of functional openings and passage openings is provided along a flow channel.

[0033] According to a preferred embodiment of the invention, the flow cross-section of at least one flow channel of the plate stack changes in the stack direction. In particular, it is possible for the flow cross-section of the flow channel to decrease in the direction of flow of a medium through the flow channel. In this way, a pressure loss along the flow channel can be compensated.

[0034] In this context, a stacking direction refers in particular to the direction along which the flow guide plates are arranged one behind the other, i.e., stacked.

[0035] According to a further development of the invention, functional openings and through-openings are arranged along at least one flow channel. In particular, through-openings and functional openings alternate along the flow channel, either in groups or alternately. Preferably, both functional openings and through-openings are arranged along all flow channels of the plate stack.

[0036] The aligned functional openings and the passage openings together form the flow channel.

[0037] According to a further development of the invention, the stack of plates comprises identical flow guide plates, wherein the identical flow guide plates are arranged in the stack of plates with a predetermined alternating angular position – in particular about the stacking direction – one after the other, preferably alternately rotated by 180° about a predetermined axis. This represents a particularly cost-effective and easy-to-assemble configuration of the plate stack, whereby identical parts can be used.This is particularly advantageous in conjunction with plates which – as described above – are designed such that, starting from a first layer of the respective flow-guiding plate in space, after a rotation of the plate by a certain angle, in particular by 90° or 180°, a passage opening in a second layer of the flow-guiding plate is located at a first location where a functional opening, selected from a media inlet and a media outlet, is arranged in the first layer, and a functional opening in the second layer is located at a second location where the passage opening in the first layer is arranged. At least one flow channel of such a plate stack then also has both functional openings and passage openings, preferably alternating, along its length.In particular, a certain periodicity in the angular position of the flow guide plates around the stacking direction results along the stacking direction, depending on the specified angle, whereby, for example, every fourth flow guide plate is arranged in the same angular position when the specified angle is 90°.

[0038] The invention will be explained in more detail below with reference to the drawing. The drawing shows: Fig. 1 a schematic representation of a first embodiment of a flow guide plate; Fig. 2 a schematic representation of a second embodiment of a flow guide plate; Fig. 3 a schematic representation of a third embodiment of a flow guide plate; Fig. 4 a schematic representation of a fourth embodiment of a flow guide plate; Fig. 5 a schematic representation of a fifth embodiment of a flow guide plate; Fig. 6 a schematic representation of a sixth embodiment of a flow guide plate; Fig. 7 a schematic representation of a seventh embodiment of a flow guide plate; Fig. 8 a schematic representation of an eighth embodiment of a flow guide plate; Fig. 9 a schematic representation of a ninth embodiment of a flow guide plate; Fig. 10 a schematic representation of a tenth embodiment of a flow guide plate; Fig. 11 a schematic representation of an eleventh embodiment of a flow guide plate; Fig. 12 a detailed representation of a flow guide of a further embodiment of a flow guide plate; Fig. 13 a schematic representation of an embodiment of a plate stack of an electrochemical cell, and Fig. 14 a schematic representation of a twelfth embodiment of a flow guide plate.

[0039] Fig. Figure 1 shows a schematic representation of a first embodiment of a flow guide plate. 1 for an electrochemical cell 3 , wherein the flow guide plate 1 a flat flow guidance area 5 features a center 7 and a periphery 9 exhibits. In the flow guidance area 5 is at least one flow guide 11 arranged. In the embodiment shown here, the flow guidance area 5 exactly three flow paths 11 on, namely a first flow guidance 11.1 , a second flow path 11.2, and a third flow path 11.3 Each of the flow paths 11 connects a media influx 13 with a media flow 15 Fluid dynamics. A first flow guidance section. 17 of each flow path 11 leads from the one in the periphery 9 arranged media flow 13 to the center 7 and goes to the center 7 into a second flow guidance section 19 over, whereby the second flow guidance section 19 from the center 7 back to the one also in the periphery 9 arranged media flow 15 leads to this. For the sake of clarity, this is only for the first flow. 11.1 Explicitly shown and provided with reference symbols, the same applies to the second flow path. 11.2 and the third flow pattern 11.3 .

[0040] Alternatively, according to another design, it is also possible that the first flow guidance section 17 from the center 7 arranged media flow 13 to the periphery 9 leads and in the periphery 9 into the second flow guidance section 19 transitions, which then originates from the periphery 9 back to what is also in the center 7 arranged media flow 15 leads.

[0041] The first flow guidance section 17 and the second flow guidance section 19 They run parallel to each other. This advantageously ensures that there is always a flow guidance section. 17 , 19 for a medium with high pressure, high concentration and / or low temperature next to another flow guidance section 17 , 19with low pressure, low concentration, and / or high temperature, so that across the entire area of ​​the flow guidance region 5 , preferably over the entire surface of the flow guide plate 1 , a constant mean value and thus a high homogeneity of the corresponding parameters is achieved.

[0042] The flow guide plate 1 is preferably a bipolar plate, a monopole plate, or a partial plate of a bipolar plate.

[0043] The electrochemical cell 3 preferably a fuel cell or an electrolysis cell.

[0044] The flow patterns 11 are preferably integrated into the flow guide plate 1 recessed, preferably in the form of a groove. It is possible that they are integrated into the flow guide plate. 1 are stamped or manufactured by machining, in particular milling.

[0045] The flow patterns 11 They are used in particular for conveying a gaseous or liquid medium, especially a reaction medium or a cooling medium.

[0046] In particular, the first flow guidance section 17 and the second flow guidance section 19 each immediately adjacent to one another, in particular side by side.

[0047] In particular, the first flow guidance section 17 and / or the second flow guidance section 19 along its length, a cumulative deflection of the media flow of more than 180° occurs, preferably at least once a 360° deflection. For example, the media flow along the first flow guide section is deflected. 17 deflected five times by 90° each time, resulting in a cumulative deflection of 450°. Considering a central transition region... 21 the flow guidance 11as a transition zone or fluid-technical connection between the first flow guidance section 17 and the second flow guidance section 19 The second flow guidance section also exhibits this. 19 five deflections of 90° each. However, it is also possible to use the transition area 21 mentally either the first flow guidance section 17 or the second flow guidance section 19 to assign, whereby the number of deflections then increases by 90° for the affected flow guidance section. 17 , 19 changes.

[0048] In the first embodiment shown here, the flow guides 11.1 , 11.2 , 11.3 a joint media influx 13 assigned, whereby each of the flow paths is simultaneously 11.1 , 11.2 , 11.3 a separate media flow 15.1 , 15.2 , 15.3is assigned.

[0049] The flow patterns 11 are spirally shaped here. In particular, in the first embodiment shown here, they have the form of an angular spiral composed of segments. The media inlet 13 and the media processes 15 They are arranged together at the edge of the spiral.

[0050] The different flow patterns 11.1 , 11.2 , 11.3 are nested within each other, each with an outer, spiral flow guide 11 an internal, spiral flow pattern 11 encompasses.

[0051] Preferably, a cross-section of the flow paths is provided. 11 in the direction of flow from the media inlet 13 to the respective media process 15 reduced. In particular, the width and / or depth of a flow path may change. 11forming groove in the direction of flow from the media inlet 13 to the media process 15 reduce. This reduction can be linear, or at least linear in certain areas.

[0052] Fig. Figure 2 shows a schematic representation of a second embodiment of a flow guide plate. 1 .

[0053] Identical and functionally equivalent elements are provided with the same reference symbols in all figures, so that reference is made to the preceding description in each case.

[0054] The second embodiment differs from the first embodiment in particular in that here each of the flow guides 11.1 , 11.2 , 11.3 both a separate media feed 13.1 , 13.2 , 13.3 as well as a separate media flow 15.1 , 15.2 , 15.3 are assigned.

[0055] Fig. Figure 3 shows a schematic representation of a third embodiment of the flow guide plate. 1 This includes all flow patterns. 11.1 , 11.2 , 11.3 a joint media influx 13 assigned, whereby the first flow path 11.1 , and the second flow pattern 11.2 a joint media workflow 15.1 is assigned. Separately from this is the third flow guide. 11.3 a separate media workflow 15.2 assigned.

[0056] Naturally, the media feed assignments shown here are... 13 and media processes 15 regarding the flow patterns 11 This is just one example. Of course, other assignments are possible.

[0057] Fig. Figure 4 shows a schematic representation of a fourth embodiment of the flow guide plate. 1 The flow pattern here 11the shape of a continuously curved spiral, for example an Archimedean spiral. Besides the media inflow. 13 and the media flow 15 The flow guide plate features functional openings. 1 Here, additionally, there are also penetrations. 23 on, which are not fluidly related to the flow guidance area 5 are connected and, in particular, for the transfer of medium to another flow guide plate 1 within a stack of flow guide plates 1 serve.

[0058] At the in Fig. The fourth embodiment shown in section 4 is the media inlet. 13 and the media flow 15 arranged on different sides of the flow guidance area - here on the one hand on the upper left and on the other hand on the upper right.

[0059] The design of the flow guidance 11The continuously curved spiral design avoids undesirably high back pressure along the flow path. 11 However, this method can create corners of the flow guidance area. 5 not through the flow guidance 11 They can be used. Therefore, functional penetrations and / or penetrations are preferred. 23 arranged in the corners.

[0060] Fig. Figure 5 shows a schematic representation of a fifth embodiment of the flow guide plate. 1 Here is the media influx. 13 and the media flow 15 side by side, especially on the same side of the flow guidance area 5 - located here at the top right. Especially when in the other corners of the flow guidance area 5 two penetrations each 23 are arranged, the same flow guide plate can be used 1They are used to build a stack of plates by rotating them at predetermined angles, i.e., in 90° increments around a point on the image plane. Fig. 5 perpendicularly oriented axis rotated, arranged one behind the other in relation to the stack of plates, preferably through the functional openings and passage openings aligned with each other. 23 Each specially designed flow channel is exposed to different media, so that the flow patterns are also varied. 11 the various flow guide plates 1 Depending on their arrangement within the stack of plates, they can be exposed to different media.

[0061] Fig. Figure 6 shows a schematic representation of a sixth embodiment of the flow guide plate. 1 This includes additional penetrations. 23 outside the flow guidance area 5The illustrated components serve in particular for the passage of a cooling medium. In a preferred embodiment, these components can be elongated and, in particular, rectangular.

[0062] Fig. Figure 7 shows a schematic representation of a seventh embodiment of the flow guide plate. 1 The additional penetrations are... 23 The design is interrupted here, providing space for assembly openings. 25 , especially for screw connections, arises. In particular, with the help of such a design, the surface area of ​​the flow guide plate can be increased. 1 can be utilized just as effectively as with a linear or rectangular flow path design. 11 .

[0063] Fig. Figure 8 shows a schematic representation of an eighth embodiment of the flow guide plate. 1 In this embodiment, the flow guide plate has... 1a plurality of flow guidance areas – in particular arranged side by side and / or one above the other – 5. Of course, the number of flow guidance areas is not limited to the four flow guidance areas shown. 5 limited. Rather, any number of flow guidance zones are possible. 5 on the flow guide plate 1 can be arranged. By arranging a plurality of flow guidance areas. 5 on the flow guide plate 1 In particular, media access can 13 and the media processes 15 The end plates of a stack of plates are further separated from each other, making them easier to connect.

[0064] Fig. Figure 9 shows a schematic representation of a ninth embodiment of the flow guide plate. 1 The flow guide plate features... 1 Here are a number of flow guidance areas. 5on, with each flow guidance area 5 at least some media attention 13 and at least one media flow 15 are assigned, wherein along at least one Cartesian direction x, y, here in particular along two Cartesian directions x, y, on the flow guidance plate 1 between each pair of media feeds 13 a media process 15 as well as between each pair of media processes 15 a media influx 13 is arranged. The media feeds 13 and media processes 15 They are therefore arranged alternately along the two Cartesian directions x and y. The two Cartesian directions x and y are perpendicular to each other and extend in the image plane of Fig. 9. Horizontal on the one hand and vertical on the other. This design has the advantage that a more uniform distribution, especially of the concentration and temperature of the medium, can be achieved, since no two inlet channels and / or outlet channels are ever located next to each other.

[0065] Fig. Figure 10 shows a schematic representation of a tenth embodiment of the flow guide plate. 1 , wherein a) a first embodiment of this exemplary embodiment – ​​as a sub-executive embodiment – ​​is shown, and b) a second embodiment of the exemplary embodiment – ​​as a second sub-executive embodiment – ​​is shown. The flow guide plate 1 In addition to this, it shows at least one media inflow. 13 and at least one media process 15 for the same medium, at least one penetration opening. 23the two sub-examples according to a) on the one hand and b) on the other hand differ in the assignment of the openings as functional openings, i.e. media inlets 13 and media processes 15 , and penetrations 23 They differ. A stack of these flow-guiding plates is preferred. 1 formed by flow guide plates 1 The plates can be arranged alternately in the stack according to the configurations a) and b). This allows every second flow-guiding plate to be used. 1 They are each fed from the same flow channels. This allows, in particular, an increase in pressure and / or concentration with which the final flow guide plates are exposed. 1 the stack of plates is fed.

[0066] Fig. Figure 11 shows a schematic representation of an eleventh embodiment of a flow guide plate. 1, which in a) are in a first position, also called the first rotation position, and in b) are rotated by 180° around a point on the image plane of Fig. The second position, also referred to as the second rotational position, is shown in 11. The flow guide plate also exhibits this characteristic. 1 in addition to the media feeds 13 and the media processes 15 penetrations for the same medium 23 open. The penetrations are... 23 and the functional openings, each having the same cross-sectional size and shape, are positioned on the flow guide plate in this manner 1 arranged so that, starting from the first rotational position of the flow guide plate shown in a), 1 in space after a 180° rotation around the image plane of Fig. 11. Vertical axis, the passage openings 23In the second rotational position, shown in b), the flow guide plates come to be located at the same position where functional openings are arranged in the first position, while simultaneously the functional openings in the second position come to be located at the same position where the through-holes are arranged in the first rotational position. This has the advantage that in a stack of identically designed flow guide plates... 1 according to Fig. 11, in which, however, the flow guide plates 1 arranged with a predetermined changing angular position, that is, alternately rotated by 180°, every second flow guide plate 1 can be fed from the same feeds, but unlike the embodiment according to Fig. 10 - Identical parts, i.e., identical flow guide plates 1 , which can be used, only needing to be arranged in an alternating, rotated or flipped manner.

[0067] In addition, the media inlets can be adjusted to ensure the most even media supply along the stack of discs. 13 and media processes 15 It should not only happen from one side, but from both sides.

[0068] The sequence of the flow guide plates must also be considered. 1 according to the tenth embodiment Fig. 10 or according to the eleventh embodiment according to Fig. 11 do not necessarily have to be alternating; rather, the flow guide plates can 1 They can also be arranged alternately in groups. The flow guide plates are also included in this arrangement. 1 arranged one behind the other with a predetermined, alternating angular position.

[0069] Fig. Figure 12 shows a schematic detail representation of a flow path 11 for another embodiment of a flow guide plate 1 The flow pattern exhibits... 11Here are several flow lines 27 , here exactly three flow lines 27 , each with the same media influx 13 and with the same media flow 15 are fluidically connected. In particular, the flow path branches out. 11 downstream of the media inlet 13 into the three flow lines 27 , whereby these are located upstream of the media flow 15 reunite. Through the correspondingly higher number of finer flow channels. 27 The solid electrolyte of an electrochemical cell 3 better supported. Furthermore, a more uniform ion distribution in the solid electrolyte is achieved, which reduces overvoltages and thus efficiency losses. This design is readily applicable to the embodiments according to the Fig. 1 to Fig. 11.

[0070] Alternatively, it is of course possible that the flow guidance 11 exactly one flow line 27 exhibits.

[0071] The flow lines 27 are preferably in the form of recesses, in particular grooves in the flow guide plate 1 trained.

[0072] Fig. Figure 13 shows a schematic representation of an embodiment of a stack of plates. 29 an electrochemical cell 3 , which includes a plurality of flow guide plates 1 according to one of the previously described embodiments. Each flow guide plate 1 at least one media outlet is involved 13 and at least one media flow 15 as functional penetrations, as well as at least one penetration penetration 23 , which are not fluidly controlled with a flow guidance area 5is connected. The functional openings as well as the penetration openings. 23 These are collectively referred to as openings. These openings in the flow guide plates 1 alignment along one stacking direction of the plate stack 29 together, with the aligned openings each forming a flow channel 31 for a medium along the stacking direction. The stacking direction extends in Fig. 13 along an arrow P.

[0073] Preferably, along at least one flow channel 31 both functional penetrations and penetrations 23 arranged.

[0074] Preferably the stack of plates 29 Identical flow guide plates 1 on, whereby the structurally identical flow guide plates 1preferably with a predetermined alternating angular position one after the other, for example alternately rotated by 180°, in the stack of plates 29 are arranged. In particular, such a stack of plates can 29 from a plurality of flow guide plates according to the eleventh embodiment according to Fig. 11 or according to the twelfth embodiment Fig. 14, but also according to the fifth embodiment after Fig. 5 must be formed.

[0075] Fig. Figure 14 shows a schematic representation of a twelfth embodiment of a flow guide plate. 1 , which in a) are in a first position or rotational position, in b) are rotated 90° clockwise around a position on the image plane of Fig. The second rotational position is shown in 14, with the axis rotated vertically; in c) in a third rotational position rotated by a further 90°, i.e., by 180° relative to a); and in d) in a fourth rotational position rotated by a further 90°, i.e., by 270° relative to a). For the sake of clarity, in Fig. 14 Only a few elements are shown for illustrative purposes, with reference symbols provided. Here too, the flow guide plate indicates 1 in addition to the media feeds 13 and the media processes 15 penetrations for the same medium 23 open. The penetrations are... 23 and the functional openings, each having the same cross-sectional size and shape, are positioned on the flow guide plate in this manner 1 arranged so that, starting from the first position of the flow guide plate shown in a), 1 in space after a 90° rotation around the image plane of Fig. 14 vertical axis penetrations 23 in the second position, as shown in b), come to be located at a place where functional openings are arranged in the first position, whereby at the same time the functional openings in the second position come to be located at a place where penetration openings are located in the first position. 23 are arranged, etc. Thus, every fourth flow guide plate can be used here. 1 are fed from the same feeds, with identical parts, i.e., identical flow guide plates. 1 , which can be used, but only need to be arranged in a specific sequence by a specific angle, here 90°, rotated or turned.

Claims

[1] Flow guide plate (1) for an electrochemical cell (3), with - at least one planar flow guidance area (5) which has a center (7) and a periphery (9), wherein - in the flow guidance area (5) at least one flow guide (11) is arranged which fluidically connects a media inlet (13) with a media outlet (15), wherein a) a first flow guidance section (17) of the flow guidance (11) leads from the media inlet (13) arranged in the periphery (9) to the center (7) and in the center (7) transitions into a second flow guidance section (19) of the flow guidance (11), which leads from the center (7) back to the media outlet (15) also arranged in the periphery (9), or b) the first flow guidance section (17) leads from the media inlet (13) located in the center (7) to the periphery (9) and transitions in the periphery (9) into the second flow guidance section (19), which leads from the periphery (9) back to the media outlet (15) also located in the center (7), wherein - the first flow guidance section (17) and the second flow guidance section (19) run parallel to each other. [2] Flow guide plate (1) according to claim 1, characterized by , that the first flow guidance section (17) and the second flow guidance section (19) run immediately adjacent to each other. [3] Flow guide plate (1) according to one of the preceding claims, characterized by , that the first flow guidance section (17) and / or the second flow guidance section (19) have a cumulative deflection of more than 180° along its / its extent. [4] Flow guide plate (1) according to one of the preceding claims, characterized by , that the flow guidance (11) is spiral in shape. [5] Flow guide plate (1) according to one of the preceding claims, characterized by , that the flow guidance area (5) has a plurality of flow guidances (11) as the at least one flow guidance (11), wherein the flow guidances (11) are preferably arranged nested within each other. [6] Flow guide plate (1) according to one of the preceding claims, characterized by , that a cross-section of the flow guide (11) decreases in the direction of flow from the media inlet (13) to the media outlet (15). [7] Flow guide plate (1) according to one of the preceding claims, characterized by, that the flow guide (11) has exactly one flow line (27) or a plurality of flow lines (27), wherein the flow lines (27) are fluidically connected to the same media inlet (13) and to the same media outlet (15). [8] Flow guide plate (1) according to one of the preceding claims, characterized by , that the flow guidance plate (1) has a plurality of flow guidance areas (5) as the at least one flow guidance area (5). [9] Flow guide plate (1) according to one of the preceding claims, characterized by , that the media inflow (13) and the media outflow (15) of the flow guidance (11) a) side by side, or b) on different sides of the flow guidance area (5) are arranged. [10] Flow guide plate (1) according to one of the preceding claims, characterized by, that the flow guidance plate (1) has a plurality of flow guidance areas (5) as the at least one flow guidance area (5), wherein each flow guidance area (5) is assigned at least one media inlet (13) and at least one media outlet (15), wherein along at least one Cartesian direction (x,y) on the flow guidance plate (1), preferably along both Cartesian directions (x,y) on the flow guidance plate (1), a media outlet (15) of the media outlets (15) is arranged between each pair of media inlets (13) of the media inlets (13) and / or between each pair of media outlets (15) of the media outlets (15) a media inlet (13) of the media inlets (13) is arranged. [11] Flow guide plate (1) according to one of the preceding claims, characterized by, that the flow guide plate (1) has, in addition to the at least one media inlet (13) and the at least one media outlet (15) for a medium, at least one passage opening (23) for the same medium. [12] Flow guide plate (1) according to claim 11, characterized by, that the at least one passage opening (23) and the at least one media inlet (13) and / or the at least one media outlet (15) have the same cross-sectional size and cross-sectional shape, wherein the flow guide plate (1) is designed such that, starting from a first position of the flow guide plate (1) in space, after a rotation of the flow guide plate (1) by a certain angle, the passage opening (23) in a second position of the flow guide plate (1) in space comes to be located at a first location where a functional opening, selected from the media inlet (13) and the media outlet (15), is arranged in the first position, and the functional opening in the second position comes to be located at a second location where the passage opening (23) in the first position is arranged. [13] A stack of plates (29) of an electrochemical cell (3), comprising a plurality of flow guide plates (1) according to any one of claims 1 to 12, wherein each flow guide plate (1) of the plurality of flow guide plates (1) has at least one media inlet (13) and at least one media outlet (15) as functional openings, and at least one through-opening (23) which is not fluidically connected to a flow guide area (5), wherein the openings of the flow guide plate (1) are aligned with each other along a stacking direction of the plate stack (29), wherein the openings aligned with each other each form a flow channel (31) for a medium along the stacking direction. [14] Stack of plates (29) according to claim 13, characterized by , that along at least one flow channel (31) both functional openings and passage openings (23) are arranged. [15] Stack of plates (29) according to one of claims 13 or 14, characterized by , that the stack of plates (19) has identical flow guide plates (1), wherein the identical flow guide plates (1) are arranged one behind the other in the stack of plates (29) with a predetermined changing angular position.

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