Bipolar plate, fuel cell system and electrolyser

Abstract

The present invention relates to a bipolar plate (100) for a chemical energy converter (200, 300). The bipolar plate (100) comprises: - a plurality of channels (101) for guiding operating media of the energy converter (200, 300), - a plurality of supply openings (103) for supplying the plurality of channels (101) with operating media, - a plurality of distribution channels (105) for distributing operating media to the plurality of channels (101), wherein respective distribution channels (105) of the plurality of distribution channels (105) extend between respective supply openings (103) of the plurality of supply openings (103) and respective channels (101) of the plurality of channels (101), and wherein respective supply openings (103) of the plurality of supply openings (103) have, on a distribution channel side which faces respective distribution channels (105) of the plurality of distribution channels (105), a curved edge region, at least in some regions.

Description

[0001] Description

[0002] title

[0003] Bipolar plate, fuel cell system and electrolyzer

[0004] The presented invention relates to a bipolar plate, a fuel cell system and an electrolyzer.

[0005] State of the art

[0006] In the cells of an energy converter, such as an electrolyzer or a fuel cell system, the respective operating media, such as reactants, must be evenly distributed across a reactive surface of the respective cells to achieve the best possible performance of the energy converter. Distribution channels, which are usually arranged in a distribution array, are used to distribute the operating media supplied through supply openings, i.e., so-called "ports," to a reactive surface.

[0007] Supply openings that are the same size as a distribution panel typically result in mechanically weak bipolar plates, so such supply openings must be reinforced with webs. However, such webs have a detrimental effect on the volume flow flowing out of a particular supply opening.

[0008] Disclosure of the invention

[0009] Within the scope of the invention presented, a bipolar plate, a fuel cell system, and an electrolyzer are presented. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the bipolar plate according to the invention naturally also apply in connection with the fuel cell system according to the invention or the electrolyzer according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0010] The invention presented serves in particular to enable efficient and robust operation of an energy converter.

[0011] Thus, according to a first aspect of the invention presented, a bipolar plate for a chemical energy converter, such as a fuel cell or an electrolyzer, is presented.

[0012] The presented bipolar plate comprises a plurality of channels for conducting operating media of the energy converter, a plurality of supply openings for supplying the plurality of channels with operating media and a plurality of supply openings for distributing operating media provided by the plurality of supply openings to the plurality of channels, wherein respective distribution channels of the plurality of distribution channels extend between respective supply openings of the plurality of supply openings and respective channels of the plurality of channels, and wherein respective supply openings of the plurality of supply openings have an edge region that is at least partially curved at least on one distribution channel side that faces respective distribution channels of the plurality of distribution channels.

[0013] In the context of the invention presented, a supply opening is understood to be a so-called “port” that supplies the bipolar plate with operating media, such as fuel or water, during operation.

[0014] In the context of the present invention, a distribution channel is understood to be a flow guide device that directs operating medium flowing out of a supply opening to respective channels or a reactive field of the bipolar plate. A distribution channel can be formed integrally from a channel or as a separate unit, particularly made of a different material than a respective channel of the bipolar plate. Of course, a distribution channel can also be made of the same material as a respective channel of the bipolar plate.

[0015] The presented invention is based on the principle that respective supply openings of the plurality of supply openings have a curved edge region at least on one distribution channel side facing respective distribution channels of the plurality of distribution channels.

[0016] The curved edge area of ​​the supply channels of the proposed bipolar plate allows the distribution channels to be arranged in such a way that they are evenly supplied with operating media, even when the distribution channels are routed around respective webs for stabilizing the bipolar plate. Accordingly, a so-called "flow shadow," i.e., a negative influence on the flow behavior of operating media flowing out of a distribution opening, is prevented or minimized.

[0017] Furthermore, the curved edge area of ​​the supply channels enables particularly advantageous flow dynamics in the distribution field with a particularly compact distribution field geometry.

[0018] It can be provided that all distribution channels are of equal length. Equally long distribution channels ensure a uniform supply of energy to the channels of the proposed bipolar plate. The curved edge area of ​​the supply openings allows the distribution channels to be of equal length and to be routed around the respective stabilizing bars.

[0019] It can further be provided that the respective supply openings are adjacent to the respective distribution channels with their distribution channel side and that the respective distribution channels extend from the respective supply openings to the respective channels.

[0020] By aligning the curved distribution channel side of each

[0021] Supply openings to respective distribution ducts are provided with additional space or additional area in which the distribution ducts can extend due to the curvature of the edge area of ​​the supply openings compared to a straight edge area.

[0022] It can further be provided that the respective distribution channels run at least partially obliquely between the distribution channel side and the respective channels.

[0023] Inclined distribution channels, i.e., distribution channels that run, for example, at an acute angle or an angle of less than 90° to a vertical axis of the bipolar plate, allow the respective distribution channels to be routed around or past the stabilizing bar in the edge areas of a stabilizing bar, thus minimizing the influence of the stabilizing bar on the flow behavior of the medium flowing through the distribution channels. The vertical axis can, for example, extend parallel to a long side of the bipolar plate.

[0024] Of course, the plurality of distribution channels provided according to the invention can comprise straight distribution channels, i.e., distribution channels running parallel to the vertical axis, and inclined distribution channels. In particular, respective distribution channels adjacent to a stabilizing web can run at an angle, and respective distribution channels arranged in a central region of a respective distribution field can run straight.

[0025] It can further be provided that an angle between a respective distribution channel and a vertical axis of the bipolar plate differs from an angle between another distribution channel and the vertical axis.

[0026] By arranging distribution channels at different angles to the vertical axis of the proposed bipolar plate, i.e., by means of a distribution channel-specific inclination or slope, the inclination of the distribution channels can be matched to the radius of curvature of a respective distribution opening, so that, regardless of the slope of a particular distribution channel, all distribution channels direct an identical or comparable volume flow of operating medium to the channels of the proposed bipolar plate. Furthermore, the distribution channels and the channels can be made of different materials.

[0027] It may also be provided that the distribution channels are made of a plastic and the channels are made of a metal.

[0028] To ensure precise shaping of the distribution channels provided according to the invention according to a predetermined arrangement, the distribution channels can be made of a particularly easy-to-shape material, such as a plastic. Accordingly, the distribution channels can be preconfigured in the form of a distribution array and incorporated into a base body of the proposed bipolar plate, which base body is made of metal, for example.

[0029] It can further be provided that the edge region of a respective supply opening is bent towards a center of the supply opening.

[0030] By means of an edge region bent towards a center of the supply opening, an area for distribution channels running between the edge region and the respective channels of the presented bipolar plate is maximized.

[0031] It can further be provided that the bipolar plate comprises a number of stabilizing webs, which in particular comprise a number of compensation channels for pressure and / or flow compensation between the supply openings.

[0032] Stabilizing webs maximize the mechanical load-bearing capacity of the bipolar plate. By integrating compensating channels into the stabilizing webs, a uniform distribution of pressure and / or flow forces is achieved between the respective regions of the bipolar plate separated by the stabilizing webs. According to a second aspect, the present invention relates to a fuel cell system with a possible embodiment of the present bipolar plate.

[0033] According to a third aspect, the presented invention relates to an electrolyzer with a possible embodiment of the presented bipolar plate.

[0034] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show:

[0035] Figure 1 is a schematic representation of a possible design of the presented bipolar plate,

[0036] Figure 2 shows a possible design of the presented fuel cell system,

[0037] Figure 3 shows a possible design of the electrolyzer presented.

[0038] Figure 1 shows a bipolar plate 100 for an energy converter, such as a fuel cell system or an electrolyzer.

[0039] The bipolar plate 100 comprises a plurality of channels 101 for conducting the operating media of the energy converter. For example, the channels 101 form a reactive field or a reactive region of the bipolar plate 100.

[0040] Furthermore, the bipolar plate 100 comprises a plurality of supply openings 103 for supplying the channels 101 with operating media or an operating medium, and a plurality of distribution channels 105 extending between the supply openings 103 and the channels 101. The supply openings 103 are bent in an edge region 107 on a distribution channel side facing the distribution channels 105.

[0041] Furthermore, Figure 1 clearly shows that the majority of the distribution channels 105 extend obliquely to a vertical axis 109. All distribution channels 105 are of equal length and are routed around stabilizing webs 111.

[0042] Optionally, the stabilizing webs 111 may comprise compensation channels 117, which enable pressure and flow compensation between the supply openings 103.

[0043] While a distribution field 113 comprises distribution channels 105 that are straight, ie parallel to the vertical axis 109, only in a central region and otherwise inclined distribution channels 105, in a distribution field 115 inclined distribution channels 105 and otherwise straight distribution channels 105 are arranged only in the outer edge region.

[0044] Due to the geometry of the distribution openings 103 and the distribution channels 105, the channels 101 are evenly supplied with operating media.

[0045] Figure 2 shows a fuel cell system 200. The fuel cell system 200 comprises a fuel cell stack 201 with a plurality of bipolar plates 100, as shown, for example, in Figure 1.

[0046] Figure 3 shows an electrolyzer 300. The electrolyzer 300 comprises a cell stack 301 with a plurality of bipolar plates 100, as shown, for example, in Figure 1.

Claims

Claims 1. Bipolar plate (100) for a chemical energy converter (200, 300), the bipolar plate (100) comprising: - a plurality of channels (101) for conducting operating media of the energy converter (200, 300), - a plurality of supply openings (103) for supplying the plurality of channels (101) with operating media, - a plurality of distribution channels (105) for distributing operating media to the plurality of channels (101), wherein respective distribution channels (105) of the plurality of distribution channels (105) extend between respective supply openings (103) of the plurality of supply openings (103) and respective channels (101) of the plurality of channels (101), and wherein respective supply openings (103) of the plurality of supply openings (103) have, at least on one distribution channel side facing respective distribution channels (105) of the plurality of distribution channels (105), an edge region (107) which is at least partially curved.

2. Bipolar plate (100) according to one of the preceding claims, characterized in that all distribution channels (105) are of equal length.

3. Bipolar plate (100) according to claim 1 or 2, characterized in that the respective supply openings (103) adjoin the respective distribution channels (105) with their distribution channel side and the respective distribution channels (105) extend from the respective supply openings (103) to the respective channels (101). Bipolar plate (100) according to one of the preceding claims, characterized in that the respective distribution channels (105) run at least partially obliquely between the distribution channel side and the respective channels (101). Bipolar plate (100) according to claim 4, characterized in that an angle between a respective distribution channel (105) and a vertical axis (109) of the bipolar plate (100) differs from an angle between a further distribution channel (105) and the vertical axis (109). Bipolar plate (100) according to one of the preceding claims, characterized in that the distribution channels (105) and the channels (101) are made of different materials. Bipolar plate (100) according to claim 6, characterized in that the distribution channels (105) are made of a plastic and the channels (101) are made of a metal.Bipolar plate (100) according to one of the preceding claims, characterized in that the edge region of a respective supply opening (103) is curved toward a center of the supply opening (103). Bipolar plate (100) according to one of the preceding claims, characterized in that the bipolar plate comprises a number of stabilizing webs (111), which in particular comprise a number of equalizing channels (117) for pressure and / or flow equalization between the supply openings (103). Fuel cell system (200). wherein the fuel cell system (200) comprises a number of bipolar plates (100) according to one of claims 1 to 9. Electrolyzer (300), wherein the electrolyzer (300) comprises a number of bipolar plates (100) according to one of claims 1 to 9.

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