Fluid guiding structure for electrochemical energy converter and electrochemical energy converter

Abstract

The invention relates to a fluid-conducting structure (50) for an electrochemical energy converter (11), comprising a separator plate (10) having a coolant passage opening (12, 13), coolant passage beads (14, 15) located at the coolant passage opening (12, 13), an active field (16) having a guide structure for guiding the coolant, edge beads (17) extending adjacent to the active field (16) and adjacent to the coolant passage beads (14, 15), 13) and the edge bead (17), a channel structure (41) for introducing the sealant (42) through the channel structure (41) into the edge bead (17), an inlet opening (43) for introducing the sealant (42) in the stacking direction (39) into the channel structure (41), and a deflection section (44) for deflecting the introduced sealant (42) from the stacking direction (39) in a transverse direction (40) to the edge bead (17). An electrochemical energy converter (11) with a fluid guiding structure (50) according to the invention.

Description

Technical Field

[0001] The invention relates to a fluid-conducting structure for an electrochemical energy converter and to an electrochemical energy converter having a plurality of fluid-conducting structures, in particular an electrochemical energy converter in the form of a fuel cell stack. Background Art

[0002] In order to make the electrochemical reaction in the fuel cell stack evenly carried out in the active field of the separator plate (especially the separator plate in the form of a bipolar plate), it is required to distribute the medium flowing on the separator plate as evenly as possible. In addition, the entire coolant flow is used for the temperature control of the active field as much as possible. However, for the known separator plates, a large part of the coolant flow will pass through the edge beads around the active field as a bypass flow, and the desired cooling effect will not be achieved. More precisely, the edge beads will inadvertently pass through the so-called through-holes, which are configured as a through-hole for guiding the coolant to flow from the coolant through-hole to the active field. For example, such a separator plate can be found in German utility model DE 20 2017 103229U1. DE 20 2017103229U1 proposes various measures to reduce and / or prevent bead bypass flow. However, the system proposed in DE 20 2017 103229U1 cannot satisfactorily avoid bypass flow or satisfactorily guide coolant. This leads to reduced cooling capacity, a negative impact on the distribution of the coolant in the active field and thus a reduced efficiency of the electrochemical system using the separator plate. The increase in the coolant flow leads to the inlet and outlet having to withstand significantly higher medium flows and thus having a correspondingly increased pressure drop. The pressure drop then has a negative impact on the desired uniform distribution. Summary of the invention

[0003] Within the scope of the invention, a fluid guide structure according to claim 1 and an electrochemical energy converter according to claim 10 are proposed, with which a more efficient and / or more effective utilization of the coolant can be achieved compared to the prior art. Further embodiments of the invention are given in the dependent claims, the description and the drawings. Here, features relating to the separator plate also apply to the energy converter according to the invention and vice versa, so that aspects of the invention can always be referred to interchangeably in the present disclosure.

[0004] According to a first aspect of the present invention, a fluid guiding structure for an electrochemical energy converter is provided, which has a separator plate. The separator plate has:

[0005] a first coolant through-opening and a second coolant through-opening for guiding the coolant through the separator plates in a stacking direction, respectively,

[0006] - a first coolant through-hole bead at the first coolant through-hole and a second coolant through-hole bead at the second coolant through-hole,

[0007] an active field having a guide structure on the front side of the active field for guiding the coolant on the front side in a lateral direction orthogonal to the stacking direction, and having a guide structure on the rear side of the active field for guiding the process fluid on the rear side in a lateral direction, and

[0008] an edge bead extending next to the active field, next to the first coolant feedthrough bead and next to the second coolant feedthrough bead,

[0009] The fluid guiding structure further comprises:

[0010] a channel structure between the first coolant through-opening and / or the second coolant through-opening and the edge bead, for guiding the sealant through the channel structure into the edge bead,

[0011] - an inlet opening for introducing sealing agent into the channel structure in the stacking direction, and

[0012] A deflecting section for deflecting the sealant introduced from the stacking direction in the transverse direction to the edge bead.

[0013] In the context of the present invention, it was first recognized that the introduction of the sealant into the edge bead can easily and reliably avoid the coolant bypass described at the outset. The sealant can be introduced particularly easily at the desired position in the edge bead by means of the channel structure proposed here and, in particular, the inlet opening for introducing the sealant in the stacking direction. In particular, the flow guiding structure according to the invention makes it possible to introduce the sealant into the channel structure in a simple and reliable manner in a mechanical and / or automatic manner.

[0014] The channel structure can have a plurality of channel sections or blind holes spaced apart from each other. At least one blind hole is preferably configured as a tunnel and / or through-hole, but can also be configured as a channel. The blind hole preferably extends obliquely or perpendicularly to the corresponding bead. The inlet opening can be understood as at least one inlet opening as described below, i.e. the fluid guiding structure can have at least one inlet opening. The fluid guiding structure preferably has a plurality of inlet openings, in particular two or four. By the configuration according to the invention of the inlet opening for introducing the sealant in the stacking direction, the inlet opening can be contacted in the axial or stacking direction without problems at the same time through a simple interface. The channel structure can in particular be configured by two mutually welded single layers of the separator plate.

[0015] Sealing agent can be understood as a kind of hardenable and / or foamable sealing fluid, and described sealing fluid can be guided to the desired position in the edge bead by the channel structure and harden there.The sealing agent hardened in the edge bead can be understood as a blocking device, which is used to block the fluid flow through the edge bead.The sealing agent can have an elastomer or be configured as an elastomer.It can be realized like this that the blocking device produced by the sealing agent will not change the deformation characteristics of the bead, and therefore the geometric shape of the matrix of the above-mentioned separator plate will not be produced to the influence of shaping.

[0016] The previously occurring bypass flow can be effectively prevented by the blocking device in the edge bead, or at least reduced to an acceptable level. The proposed solution can be easily integrated into existing systems. Existing structures hardly need to be changed. This leads to low costs for implementing the solution according to the invention.

[0017] The separator plate can be understood as a bipolar plate, a monopolar plate and / or a part of a bipolar plate. The electrochemical energy converter can be understood as a fuel cell, and in particular a fuel cell stack. The separator plate preferably has an integral and / or monolithic matrix, which has a first coolant through-opening, a second coolant through-opening, a first coolant through-bead, a second coolant through-bead, an active field and an edge bead. The terms "front side" and "rear side" are selected only to distinguish between different outer sides. Therefore, the terms can also be used interchangeably.

[0018] The first coolant passage is preferably configured to introduce a coolant into the electrochemical system, and the second coolant passage is preferably configured to discharge a coolant from the electrochemical system. The coolant passage beads and the edge beads are separated or spaced apart from each other at least in sections by a spacer (eg an edge bead).

[0019] The channel structure is preferably configured to guide the sealant into the edge bead next to the corresponding coolant through-bead. This can be understood to mean that the sealant can be guided into a section of the edge bead that extends next to and / or along the corresponding coolant through-bead, in particular adjacent to it. The blocking means generated by the sealant can extend within the edge bead or at least substantially within the edge bead, preferably bend linearly next to the corresponding coolant through-bead. Thus, the sealant can be introduced into a portion of the groove or recess formed by the edge bead by means of the channel structure.

[0020] The first coolant permeation bead and the second coolant permeation bead each preferably extend completely around the corresponding coolant permeation opening. The edge bead preferably extends through along a portion of the coolant permeation bead and along the outer edge of the active field. The coolant permeation bead is preferably configured outside the ring or closed loop formed by the edge bead. The process fluid can be understood as hydrogen, a hydrogen-containing fluid, oxygen and / or an oxygen-containing fluid, especially air.

[0021] Furthermore, it is possible that the separator plate according to the invention has

[0022] a first hydrogen through-opening for conducting hydrogen through the separator plate and a first hydrogen through-opening bead on the first hydrogen through-opening,

[0023] a first oxygen through-opening for conducting oxygen through the separator plate and a first oxygen through-opening bead on the first oxygen through-opening,

[0024] - a second hydrogen feedthrough opening for passing hydrogen through the separator plate and a second hydrogen feedthrough bead on the second hydrogen feedthrough opening, and

[0025] a second oxygen through-opening for conducting oxygen through the separator plate and a second oxygen through-opening bead at the second oxygen through-opening,

[0026] The channel structure is configured to guide the sealant to a portion of the edge bead in which the edge bead extends between the first coolant through-bead and the first hydrogen through-bead, between the first coolant through-bead and the first oxygen through-bead, between the second coolant through-bead and the second hydrogen through-bead, and / or between the second coolant through-bead and the second oxygen through-bead. At these locations, an effective blocking effect or a desired sealing effect can be achieved at low cost and material expenditure.

[0027] It has also proven to be particularly advantageous if the channel structure in the separator plate is configured so that the channel leading to

[0028] - a portion of the edge bead in which the edge bead extends between the first coolant feed-through bead and the first hydrogen feed-through bead,

[0029] - a portion of the edge bead in which the edge bead extends between the first coolant feedthrough bead and the first oxygen feedthrough bead,

[0030] - a portion of the edge bead in which the edge bead extends between the second coolant feedthrough bead and the second hydrogen feedthrough bead, and

[0031] - in a portion of the edge bead in which the edge bead extends between the second coolant feed-through bead and the second oxygen feed-through bead.

[0032] In this way, the blocking means can be produced at a point where a particularly effective sealing effect is produced to prevent bypass flows, so that the coolant can be conducted into the active field as loss-free as possible, as desired.

[0033] Alternatively to the above-mentioned configuration variant, the channel structure is configured so that the sealing agent can be guided only to

[0034] - a portion of the edge bead in which the edge bead extends between the first coolant feedthrough bead and the first hydrogen feedthrough bead, and

[0035] - in a portion of the edge bead in which the edge bead extends between the second coolant feed-through bead and the second hydrogen feed-through bead.

[0036] It is also possible that in the separator plate according to the invention the channel structure is designed such that the sealing agent is only directed to the

[0037] - a portion of the edge bead in which the edge bead extends between the first coolant feedthrough bead and the first hydrogen feedthrough bead, and

[0038] - in a portion of the edge bead in which the edge bead extends between the first coolant feed-through bead and the first oxygen feed-through bead.

[0039] In addition, the channel structure can be configured so that the sealant can be guided into the first coolant through-bead next to the edge bead and / or the second coolant through-bead next to the edge bead, so that at least one additional blocking device can be formed there for blocking the flow of fluid through the first coolant through-bead and / or the second coolant through-bead. At least one additional blocking device can extend linearly and / or curvedly in the corresponding coolant through-bead, corresponding to the above-mentioned blocking device, following the corresponding coolant through-spacer. By means of at least one additionally configured blocking device, the blocking and / or sealing effect can be simply and cost-effectively enhanced.

[0040] According to another embodiment of the invention, it is possible that the inlet opening is configured in a funnel shape. This allows the sealing agent to be reliably conveyed into the channel structure in a simple manner. High-precision automated operations for introducing the sealing agent into the channel structure can be omitted.

[0041] It is also possible that the channel structure of the fluid-conducting structure according to the invention is formed by two sheet metal structures welded to one another, wherein at least one weld seam is configured to partially surround and / or partially annularly surround the inlet opening in order to connect the two sheet metal structures to one another in a materially bonded manner. The weld seam or corresponding welding can reliably prevent the sealing material from penetrating into the port region or the coolant opening in a simple manner. Furthermore, it can be prevented that the individual layers of the separator plate are pressed apart in the event of a possible foaming of the sealant.

[0042] It is also feasible that, according to the present invention, the channel structure of the fluid guiding structure can be formed by two mutually welded sheet structures, wherein at least one weld is configured between the first coolant through-hole and the first coolant through-hole bead and / or between the second coolant through-hole and the second coolant through-hole bead, for connecting the two sheet structures to each other in a material-locked manner. Such a weld or a corresponding welding process can reliably prevent the sealant from penetrating in the direction of the active area and / or distributor area of ​​the separator plate in a simple manner. This means that the weld can be configured not only around the inlet opening, but also along the coolant through-hole bead. The weld can be configured as a separate weld, or as a part of the entire weld, and the entire weld includes the above-mentioned weld extending around the inlet opening. The weld or welded portion can partially extend along the corresponding coolant through-hole bead.

[0043] According to another embodiment variant of the invention, it is possible that in the fluid guiding structure the inlet opening can be configured in and / or on the first coolant through-opening and / or the second coolant through-opening. In this area, the inlet opening can be configured without, or at least substantially without, affecting the sealing function of the separator plate, and can be retrofitted and / or adjusted in an existing separator plate design.

[0044] It is also possible that in the fluid guiding structure according to the invention the channel structure is designed as an integrated and / or integral component of the first coolant through-bead, the second coolant through-bead and / or the edge bead. This makes it possible to realize the channel structure in a particularly space-saving manner. In particular, the channel structure can be designed as part of the embossing pattern of the separator plate.

[0045] In the fluid guiding structure according to the present invention, the inlet structure with the inlet opening and the deflection section can also be configured as an integrated and / or integral component of the separator plate. That is, the inlet opening or the structural member including the inlet opening and the deflection section can be provided as an integrated and / or integral component of the separator plate and / or two single layers of the separator plate. Alternatively or additionally, it is feasible that in the fluid guiding structure according to the present invention, the inlet structure is configured to be loosened from the separator plate without loss, or to be separated from the separator plate after the sealant is introduced. That is, in addition to or instead of the integrated inlet structure, the inlet structure can also be provided as an adapter component, which is fastened to the separator plate and / or positioned on the separator plate so as to introduce the sealant at a desired position in the separator plate and / or on the separator plate, and can be removed again afterwards. This brings the following advantages in particular, that the inlet structure can be removed from the coolant through-port when the electrochemical energy converter is running.

[0046] Furthermore, in the fluid guiding structure according to the present invention, the channel structure can be configured to guide the sealant through the channel structure into the first coolant through-bead and / or the second coolant through-bead. That is, the sealant can not only enter the edge bead by means of the channel structure, but also enter the corresponding coolant through-bead. Therefore, a space-saving and functionally reliable measure is provided by the channel structure for simply manufacturing the blocking device in the first coolant through-bead and / or the second coolant through-bead.

[0047] According to another aspect of the invention, an electrochemical energy converter having a plurality of the above-described fluid guiding structures is proposed. The energy converter according to the invention thus has the same advantages as the fluid guiding structure according to the invention described in detail. The electrochemical energy converter can be understood in particular as a fuel cell or a fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Further measures for improving the invention are described below in the description of various embodiments of the invention, which are schematically shown in the drawings. All features and / or advantages arising from the claims, the description or the drawings, including structural details and spatial arrangements, are essential to the invention, either individually or in any combination.

[0049] It schematically shows:

[0050] Figure 1 According to the fluid guiding structure of the first embodiment of the present invention,

[0051] Figure 2 According to the channel structure of the fluid guiding structure of the second embodiment of the present invention,

[0052] Figure 3 A fluid guiding structure according to a third embodiment of the present invention, and

[0053] Figure 4 Electrochemical energy converter with a separator plate according to the invention.

[0054] Elements having the same function and mode of action are provided with the same reference symbols in the figures. DETAILED DESCRIPTION

[0055] Figure 1 FIG. 1 shows a method for Figure 4. The fluid guiding structure 50 of the electrochemical energy converter 11 shown in FIG. The fluid guiding structure 50 has a separator plate 10, which has a first coolant through-hole 12 for guiding the coolant through the separator plate 10 in the stacking direction 39. The separator plate 10 also includes a first coolant through-hole 14 and an active field 16 at the first coolant through-hole 12, the active field having a guide structure on the front side of the active field 16 for guiding the coolant on the front side in a transverse direction 40 orthogonal to the stacking direction 39, and a guide structure on the rear side of the active field 16 for guiding the process fluid on the rear side in the transverse direction 40. In addition, the separator plate 10 also has an edge bead 17, which extends beside the active field 16 and the first coolant through-hole 14 or partially along it. The fluid guiding structure 50 has a channel structure 41 between the first coolant through-hole 12 and the edge bead 17, which is used to guide the sealant 42 through the channel structure 41 into the edge bead 17. For this purpose, the fluid guiding structure 50 also has an inlet opening 43 for introducing the sealant 42 into the channel structure 41 in the stacking direction 39 and a deflection section 44 for deflecting the sealant 42 introduced from the stacking direction 39 in the transverse direction 40 to the edge bead 17. Figure 1 As can be seen in the figure, the channel structure 41 is formed by two sheet metal structures welded to each other, wherein the weld 45 for connecting the two sheet metal structures to each other in a material-locked manner is configured to be partially annular or partially surround the inlet opening 43. The weld is also configured along a portion of the first coolant penetration bead 14. Another weld 45 is configured along the edge bead 17. The inlet opening 43 and the deflection section 44 are configured as part of the inlet structure 46, wherein the inlet structure 46 is configured as an integrated component of the separator plate 10. The inlet structure 46 is configured in the first coolant through-hole 12. The channel structure 41 is configured as an integrated component of the first coolant penetration bead 14 and the edge bead 17. The channel structure 41 is also configured to guide the sealant 42 into the first coolant penetration bead 14.

[0056] Figure 2 The channel structure 41 of the fluid guiding structure 50 according to the second embodiment is shown. According to this embodiment, the inlet structure 46, which has the inlet opening 43 and the deflection section 44, is configured as an adapter component, which can be positioned at the channel opening in the first coolant passage 12 of the separator plate 10 in order to introduce the sealant 42 into a part of the channel structure 41 in the direction of the edge bead 17 and can then be released again in a non-destructive manner.

[0057] Figure 3A fluid guiding structure 50 with a separator plate 10 according to another embodiment is shown. The separator plate 10 shown has a first coolant through-hole 12 and a second coolant through-hole 13 for guiding the coolant through the separator plate 10 accordingly. In addition, the separator plate 10 also includes a first coolant through-hole 14 at the first coolant through-hole 12, a second coolant through-hole 15 at the second coolant through-hole 13, and an active field 16, the active field having a guide structure on the front side of the active field for guiding the coolant on the front side, and having a guide structure on the rear side of the active field 16 for guiding the process fluid on the rear side. In addition, the separator plate has an edge bead 17, which extends through the active field 16, the first coolant through-hole bead 14, and the second coolant through-hole bead 15. Two blocking devices 18 are configured in the edge bead 17 next to the first coolant through-hole bead 14 and the second coolant through-hole bead 15, respectively, for blocking the fluid flow through the edge bead 17 at these positions. The barrier device 18 is formed by introducing a sealant 42 into the Figure 1 The channel structure 41 shown in FIG. 4 is then formed by curing the sealant 42. Figure 3 In the separator plate 10 shown in FIG, two blocking means 19 are respectively configured in the first coolant through-bead 14 next to the edge bead 17 and in the second coolant through-bead 15 next to the edge bead 17 for blocking the fluid flow through the first coolant through-bead 14 and through the second coolant through-bead 15 at these locations. In order to produce the blocking means 19, a channel structure 41 with four blind holes 26, 27, 28, 29 is configured in the separator plate 10, wherein the channel structure 41 or the blind holes 26, 27, 28, 29 are respectively configured to guide a sealing agent 42 into the first coolant through-bead 14 and the second coolant through-bead 15 in order to produce the corresponding blocking means 18, 19 there.

[0058] like Figure 3 As shown, the separator plate 10 also includes a first hydrogen through-hole 30 for guiding hydrogen or a fluid containing hydrogen to pass through the separator plate 10 and first hydrogen through-hole beads 34 surrounding the first hydrogen through-hole 30, a first oxygen through-hole 31 for guiding oxygen or a fluid containing oxygen (especially air) to pass through the separator plate 10 and first oxygen through-hole beads 35 surrounding the first oxygen through-hole 31, a second hydrogen through-hole 32 for guiding hydrogen to pass through the separator plate 10 and second oxygen through-hole beads 36 surrounding the second hydrogen through-hole 32, and a second oxygen through-hole 33 for guiding oxygen to pass through the separator plate 10 and second oxygen through-hole beads 37 surrounding the second oxygen through-hole 33.

[0059] exist Figure 3The embodiment shown in the figure also includes a first coolant through-spacer 22 configured between the first coolant through-opening 12 and the first coolant through-bead 14, a second coolant through-spacer 23 configured between the second coolant through-opening 13 and the second coolant through-bead 15, a first edge bead spacer 24 configured between the first coolant bead 14 and the edge bead 17, and a second edge spacer 25 configured between the second coolant bead 15 and the edge bead 17. The separator plate 10 shown also has conventional through holes 38 for introducing coolant into the active field 16.

[0060] Figure 4 An electrochemical energy converter 11 is shown in the form of a fuel cell stack, wherein separator plates 10 are shown symbolically. In a real fuel cell stack, a large number of separator plates 10 are naturally arranged in this manner.

[0061] In addition to the embodiments shown, the present invention also allows other configurations. That is, the present invention should not be considered to be limited to the embodiments explained with reference to the drawings.

Claims

1. A fluid guiding structure (50) for an electrochemical energy converter (11), comprising a separator plate (10) having a first coolant through-opening (12) and a second coolant through-opening (13) for guiding a coolant through the separator plate (10) in a stacking direction (39), - a first coolant through-hole (14) at the first coolant through-hole (12) and a second coolant through-hole (15) at the second coolant through-hole (13), - an active field (16) with guide structures on the front side of the active field (16) for guiding the coolant on the front side in a transverse direction (40) orthogonal to the stacking direction (39), and with guide structures on the rear side of the active field (16) for guiding the process fluid on the rear side in the transverse direction (40), and an edge bead (17) extending next to the active region (16), next to the first coolant passage bead (14) and next to the second coolant passage bead (15), It is characterized in that - a channel structure (41) is provided between the first coolant through-hole (12) and / or the second coolant through-hole (13) and the edge bead (17), for guiding a sealant (42) through the channel structure (41) and into the edge bead (17), - an inlet opening (43) is provided for introducing the sealing agent (42) into the channel structure (41) along the stacking direction (39), and A deflection section (44) is provided for deflecting sealing agent (42) introduced from the stacking direction (39) in the transverse direction (40) towards the edge bead (17).

2. The fluid guiding structure (50) according to claim 1, It is characterized in that The inlet opening (43) is designed in a funnel-like manner.

3. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that The channel structure (41) is formed by two sheet metal structures welded to one another, wherein at least one weld seam (45) serves to connect the two sheet metal structures to one another in a materially bonded manner, the at least one weld seam being designed to partially surround the inlet opening (43).

4. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that The channel structure (41) is formed by two sheet metal structures welded to each other, wherein at least one weld seam (45) is used to connect the two sheet metal structures to each other in a material-locked manner, and the at least one weld seam is configured between the first coolant through-hole (12) and the first coolant through-hole bead (14), and / or between the second coolant through-hole (13) and the second coolant through-hole bead (15).

5. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that The inlet opening (43) is formed in and / or on the first coolant passage (12) and / or the second coolant passage (13).

6. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that The channel structure (41) is configured as an integrated and / or monolithic component of the first coolant passage bead (14), the second coolant passage bead (15) and / or the edge bead (17).

7. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that An inlet structure (46) is provided, which has the inlet opening (43) and the deflection section (44), wherein the inlet structure (46) is designed as an integrated and / or monolithic component of the separator plate (10).

8. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that An inlet structure (46) is provided, which has the inlet opening (43) and the deflection section (44), wherein the inlet structure (46) is configured to be non-destructively releasable from the separator plate (10).

9. The fluid guiding structure (50) according to any one of the preceding claims, It is characterized in that The channel structure (41) is configured to guide the sealant (42) through the channel structure (41) into the first coolant penetration bead (14) and / or the second coolant penetration bead (15).

10. An electrochemical energy converter (11) having a plurality of fluid-conducting structures (50) according to any one of the preceding claims.

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