Separator for fuel cell

Abstract

A separator for a fuel cell includes a plurality of flow channels configured to flow gas or product water, and the plurality of flow channels are provided with a plurality of protrusions protruding in a first direction and a second direction at a plurality of points, each of the plurality of flow channels is provided with a corresponding protrusion of the plurality of protrusions at a set point thereof, while an adjacent flow channel is not provided with a protrusion at a point corresponding to the set point of the previous flow channel, and a portion of the protrusions protruding in one of the first direction and the second direction are aligned on one straight line.

Description

Technical Field

[0001] The present invention relates to a separator for a fuel cell. Background Art

[0002] A fuel cell is a device that receives hydrogen and air from the outside and generates electrical energy through an electrochemical reaction in a fuel cell stack. Fuel cells can be used as power sources in various fields of fuel cell electric vehicles, fuel cells for power generation, and the like.

[0003] A typical fuel cell system includes a fuel cell stack in which a plurality of unit cells are stacked, a fuel supply system configured to supply hydrogen or the like as fuel for the fuel cell stack, an air supply system configured to supply oxygen as an oxidant required in the electrochemical reaction, a water and thermal management system configured to control the temperature of the fuel cell stack, and the like.

[0004] When hydrogen is supplied to the anode of the fuel cell stack and oxygen is supplied to the cathode of the fuel cell stack, hydrogen ions and oxygen ions are generated by the catalyst and electrochemically react with each other, thereby generating electric energy and water (product water).

[0005] A fuel cell stack is composed of hundreds of repeatedly stacked unit cells, and the unit cells include an anode, a cathode, an electrolyte membrane, and a separator. In particular, the separator has flow channels through which hydrogen and air flow. The design of the flow channels in the separator is one of the key areas for improving the performance of the fuel cell stack.

[0006] The details described as background art are only intended to facilitate understanding of the background of the invention and should not be construed as an admission that the prior art is known to the public. Summary of the invention

[0007] The present invention relates to a separator for a fuel cell constituting a unit cell of a fuel cell stack. Therefore, the present invention is made in view of the above problems, and an embodiment of the present invention can provide a separator for a fuel cell, wherein a vertical flow of air is established between adjacent flow channels formed in the separator, so that product water in the fuel cell stack can be easily discharged, the residence time of the gas introduced into the fuel cell stack is increased, and the utilization rate of the gas is increased, thereby improving the performance of the fuel cell stack.

[0008] According to an embodiment of the present invention, the above and other advantages can be achieved by providing a separator for a fuel cell, the separator including a plurality of flow channels through which gas or product water flows, and having protrusions protruding in a first direction and a second direction at a plurality of points thereof. In an embodiment, each of the plurality of flow channels can be provided with a corresponding protrusion at a preset, selected or designed point thereof, while an adjacent flow channel is not provided with a protrusion at a point corresponding to a preset, selected or designed point of the previous flow channel, and a portion of the protrusions protruding in one of the first direction and the second direction are aligned on the same straight line.

[0009] In an embodiment, the shape of each protrusion is a streamline shape having no corners therein or an angled shape having two or more corners.

[0010] In an embodiment, the plurality of flow channels may include a first flow channel having a protrusion protruding therein in a first direction and a second flow channel having a protrusion protruding therein in a second direction.

[0011] In an embodiment, the first flow channels and the second flow channels may be alternately arranged.

[0012] In an embodiment, the protrusions provided in the first flow channel or the protrusions provided in the second flow channel may be aligned on the same straight line.

[0013] In an embodiment, the plurality of flow channels may be defined between a plurality of boss members that protrude upward while extending in an extending direction of the plurality of flow channels, and the boss members are spaced apart from each other.

[0014] In an embodiment, the plurality of boss members may include a first boss member on which a protrusion is formed to protrude toward the flow channel, and a second boss member on which no protrusion is formed.

[0015] In an embodiment, the first boss members and the second boss members may be alternately arranged.

[0016] In an embodiment, each of the first boss members may have a straight line shape, and each of the second boss members may have a partially concave or convex streamline shape.

[0017] In an embodiment, the first boss member and the second boss member may be arranged in the direction of gravity.

[0018] In an embodiment, the surface area of ​​the second boss member gradually decreases towards the ground.

[0019] In an embodiment, a groove may be provided in a portion of the second boss member corresponding to the protrusion formed on the first boss member.

[0020] In an embodiment, the protrusion may protrude toward the second boss member such that a portion or all of the protrusion contacts the second boss member.

[0021] In an embodiment, a portion of each protrusion may have a groove formed therein through which gas flows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other features and other advantages of the embodiments of the present invention will be more clearly understood through the following detailed description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 is a view showing a portion of a separator according to a first embodiment of the present invention;

[0024] Figure 2 is a view showing the flow of air in a portion of a partition plate according to a first embodiment of the present invention;

[0025] Figure 3 is a cross-sectional view showing a separator according to a second embodiment of the present invention;

[0026] Figure 4 is a cross-sectional view showing a separator according to a third embodiment of the present invention;

[0027] Figure 5 is a cross-sectional view showing a separator according to a fourth embodiment of the present invention;

[0028] Figure 6 is a cross-sectional view showing a separator according to a fifth embodiment of the present invention;

[0029] Figure 7 is a cross-sectional view showing a separator according to a sixth embodiment of the present invention;

[0030] Figure 8 is a cross-sectional view showing a separator according to a seventh embodiment of the present invention; and

[0031] Fig. 9 It is a cross-sectional view showing a separator according to an eighth embodiment of the present invention. DETAILED DESCRIPTION

[0032] Now, the exemplary embodiments disclosed herein will be described in detail with reference to the accompanying drawings. For the sake of brevity in the description with reference to the accompanying drawings, the same or equivalent components may be represented by the same reference numerals, and their description will not necessarily be repeated.

[0033] In addition, in the following description of the embodiments disclosed herein, if it is determined that a detailed description of known functions or configurations related to the present invention will obscure the subject matter of the present invention, such detailed description may be omitted. The accompanying drawings may be used to help easily understand the various technical features, and it should be understood that the embodiments presented herein are not necessarily limited by the accompanying drawings. Therefore, in addition to those specifically listed in the accompanying drawings, the present invention may be interpreted as extending to any changes, equivalents, and alternatives.

[0034] It should be understood that although the terms "first", "second", etc. may be used to describe various elements in this article, these elements should not be interpreted as being limited by these terms. These terms may be used only to distinguish one element from another. Unless the context clearly indicates otherwise, a singular expression may include a plural expression.

[0035] The terms such as “including” or “having” used in this document should be regarded as indicating the existence of various features, numbers, steps, operations, elements, parts or their combinations disclosed in the specification, and it should be understood that the existence or addition of one or more other features, numbers, steps, operations, elements, parts or their combinations are not excluded.

[0036] Figure 1 It is a view showing a part of the separator according to the first embodiment of the present invention. Figure 2 This is a diagram showing the flow of air in a part of the partition plate according to the first embodiment of the present invention. Figure 3 It is a cross-sectional view showing a separator according to a second embodiment of the present invention. Figure 4 It is a cross-sectional view showing a separator according to a third embodiment of the present invention. Figure 5 : is a cross-sectional view showing a separator according to a fourth embodiment of the present invention. Figure 6 : is a cross-sectional view showing a separator according to a fifth embodiment of the present invention. Figure 7 : is a cross-sectional view showing a separator according to a sixth embodiment of the present invention. Figure 8 It is a cross-sectional view showing a separator according to a seventh embodiment of the present invention. Fig. 9 It is a cross-sectional view showing a separator according to an eighth embodiment of the present invention.

[0037] For reference, Figures 2 to 8 The cross section is shown when the partition is erected vertically relative to the ground.

[0038] The separator of the embodiment of the present invention to achieve the above-mentioned purpose may include a plurality of flow channels 100 through which gas or product water flows in the direction in which the separator extends, and the plurality of flow channels 100 include a plurality of protrusions 300 protruding from a plurality of points in one direction or in the opposite direction. In an embodiment, a flow channel adjacent to a flow channel provided with the protrusion 300 is not provided with the protrusion 300, and the protrusions 300 protruding in the same direction are located on the same straight line.

[0039] Figure 1 A part of the separator according to the first embodiment of the present invention is shown.

[0040] The separator of the first embodiment of the present invention is provided with a plurality of flow channels 100 through which gas (ie, air or hydrogen) and product water generated by the reaction of hydrogen with oxygen in the air can flow.

[0041] like Figure 1 As shown, specifically, the relatively concave portion of the partition may define the flow channel 100, and the relatively protruding portion of the partition may define the sidewall configured to guide the flow of gas. Hereinafter, it may be assumed that the gas is air, and embodiments of the present invention will be described based on the flow of air.

[0042] The flow channel 100 is provided with a protrusion 300 that protrudes in one direction or in the opposite direction. The protrusion 300 may be formed on the side wall of the flow channel, and air colliding with the protrusion 300 may be reflected by the protrusion 300 and then flow in the protruding direction of the protrusion 300. Figure 2 As shown, the air colliding with the protrusion 300 may flow over the side wall, and may be introduced into the adjacent flow channel 100. Therefore, the air may flow between the adjacent flow channels 100.

[0043] In other words, the protrusion 300 causes a portion of the air in the flow channel 100 to flow while having a wave shape, and causes a portion of the air in the flow channel 100 to flow into an adjacent flow channel to form a vertical flow of air between the adjacent flow channels 100 .

[0044] In the embodiment, the protrusion 300 provided in one flow channel 100 protrudes in one direction (one side) or in the opposite direction (opposite side), so that the flow channel 100 is provided with only the protrusion 300 protruding in one direction, and the adjacent flow channel 100 is provided with the protrusion 300 protruding in the opposite direction. Therefore, in the embodiment, there is no case where the protrusion protruding in one direction and the protrusion protruding in the opposite direction are provided in one flow channel 100 at the same time.

[0045] In other words, in the embodiment, the protrusion 300 is not provided at a point of one flow channel 100 corresponding to a point of an adjacent flow channel 100 at which the protrusion 300 is provided, but is provided at a point of the one flow channel spaced apart from the protrusion provided in the adjacent flow channel 100. Figure 1 Specifically, when a protrusion 300 protruding in one direction is provided in a flow channel 100, another protrusion 300 protruding in the opposite direction is not provided at a point of an adjacent flow channel 100 corresponding to the protrusion 300, but is provided at a point of the adjacent flow channel 100 spaced apart from the protrusion 300.

[0046] In other words, in the embodiment, a protrusion 300 protruding in one direction and another protrusion 300 protruding in the opposite direction are disposed at points spaced apart from each other in a diagonal (oblique) direction.

[0047] like Figure 1 As shown, in an embodiment, the protrusions 300 protruding in one direction are aligned on the same straight line A-A', and the protrusions 300 protruding in the opposite direction are aligned on another same straight line BB'. In other words, in an embodiment, the protrusions 300 protruding in the same direction may be located on the same straight line. Figure 1 In an embodiment, the protrusions 300 protruding in one direction are aligned on the line CC', and the protrusions 300 protruding in the opposite direction are aligned on the line BB'.

[0048] refer to Figure 1 and Figure 2 , a protrusion 300 protruding in one direction is arranged at a point of a flow channel 100 and at a corresponding point of a flow channel 100 of a flow channel 100 adjacent to the flow channel 100, and a protrusion 300 protruding in the opposite direction is also arranged at a point of a flow channel 100 and at a corresponding point of a flow channel 100 of a flow channel 100 adjacent to the flow channel 100.

[0049] Therefore, in an embodiment, air reflected by the protrusion 300 may stably flow into adjacent flow channels 100 , thereby ensuring smooth vertical movement between adjacent flow channels 100 .

[0050] In other words, in the embodiment, if the protrusion 300 protruding in the same direction is provided at one point of one flow channel 100 and at a corresponding point of an adjacent flow channel 100, the distance that the air moves vertically between the adjacent flow channels 100 can be increased. For this reason, in the embodiment, the protrusion 300 protruding in one direction and the protrusion 300 protruding in the opposite direction are provided at points of the adjacent flow channels spaced apart from each other in the diagonal (oblique) direction, rather than at corresponding points of the adjacent flow channels 100.

[0051] Therefore, by the embodiment, the residence time of air or hydrogen flowing in the separator can be increased, and the contact time between the separator and the air or hydrogen can be increased due to the increase in the residence time, thereby increasing the utilization rate of the gas. As a result, for the embodiment, the performance of the fuel cell stack can be improved.

[0052] For the embodiments, each protrusion 300 may be configured to have various shapes. Figure 3 As shown, the protrusion 300 according to the second embodiment may have a streamlined shape without a corner therein. Meanwhile, the protrusion 300 may have an angular shape having two or more corners therein, that is, a rectangular shape (third embodiment) or a triangular shape (fourth embodiment), respectively. Figure 4 and Figure 5 shown.

[0053] The shape of the protrusion 300 is not limited to the above-described shape, and the protrusion 300 of the embodiment may be configured in any shape among a shape having two or more corners and a shape having a streamlined portion.

[0054] In an embodiment, if Figure 1 and Figure 2 As shown, the flow channel 100 is provided with two types of protrusions 300 protruding in two directions. Among the flow channels 100, the flow channel 100 provided with the protrusions 300 protruding in one direction is referred to as the first flow channel 130, and the flow channel provided with the protrusions 300 protruding in the opposite direction is referred to as the second flow channel 170.

[0055] In another expression of the embodiment, the flow channel 100 defined in the partition may include a first flow channel 130 and a second flow channel 170, and the first flow channel 130 and the second flow channel 170 may be arranged alternately. In other words, the first flow channel 130 including the protrusion 300 protruding in one direction and the second flow channel 170 interposed between the first flow channels 130 are alternately formed.

[0056] like Figure 1As shown, the protrusions 300 disposed in the first flow channel 130 may be aligned on the same straight line (line AA' or line CC'), and the protrusions 300 disposed in the second flow channel 170 may be aligned on another straight line (line BB').

[0057] like Figure 1 and Figure 2 As shown, the side wall on which the protrusion 300 is formed may be referred to as a boss member 500. In an embodiment, the boss members 500 relatively protrude upward, and accordingly, a relatively recessed recessed portion is formed between the protruding boss members 500 and serves as a flow channel 100. A plurality of boss members 500 may be formed to be spaced apart from each other at a preset, selected, predetermined, or designed distance, thereby defining a flow channel 100 therebetween.

[0058] In an embodiment, if Figure 1 and Figure 2 As shown, the boss member 500 includes a first boss member 530 and a second boss member 570. The first boss member 530 is provided with a protrusion 300 protruding toward the flow channel 100, while the second boss member 570 is not provided with the protrusion 300. In the embodiment, like the first flow channel 130 and the second flow channel 170 that are alternately arranged, the first boss member 530 and the second boss member 570 may also be alternately arranged.

[0059] refer to Figure 1 and Figure 2 Each first boss member 530 includes a protrusion 300 protruding in one direction and a protrusion 300 protruding in the opposite direction. The protrusions 300 protruding in one direction and the protrusions 300 protruding in the opposite direction are formed on the first boss member 530 so as to be spaced apart from each other in an alternating manner in the extending direction of the flow channel 100.

[0060] Meanwhile, in the embodiment, each first boss member 530 formed with the protrusion 300 may be configured in a straight line shape, and each second boss member 570 not formed with the protrusion 300 may be configured in a streamlined shape having a partially concave or convex shape. Figure 6 Since each of the second boss members 570 that do not form the protrusion 300 has a streamlined shape (eg, wave-shaped), the wave motion of the air flowing in the flow channel may be increased, thereby further increasing the residence time of the air.

[0061] In an embodiment, the fuel cell stack may be oriented so that the introduction direction of air and hydrogen is perpendicular to the gravity direction. The reason for this is to enable product water generated by the reaction between air and hydrogen to move toward the lower side of the fuel cell stack due to gravity.

[0062] Therefore, the first boss member 530 and the second boss member 570 formed in the separator may be arranged in the gravity direction, and the flow channels defined by the first boss member 530 and the second boss member 570 may also be arranged in the gravity direction.

[0063] According to the sixth embodiment of the present invention (see Figure 7 ), the second boss member 570 may be configured such that the closer the second boss member 570 is to the ground, the smaller the protrusion height is. Figure 7 , which shows a sixth embodiment of the present invention, it should be noted that the surface area of ​​the second boss member 570 decreases gradually (in stages) in the direction of gravity.

[0064] When the surface area of ​​second boss member 570 decreases in a stepwise fashion from the upper end toward the lower end of the fuel cell stack, friction between product water collected at the lower end of the fuel cell stack due to gravity and second boss member 570 can be reduced, thereby facilitating discharge of product water.

[0065] According to the seventh embodiment of the present invention (see Figure 8 ), a groove 575 recessed from a portion of the second boss member 570 corresponding to the protrusion 300 formed on the first boss member 530 may be provided in the portion. Figure 8 The seventh embodiment of the present invention is shown together with an enlarged view of the second boss member 570 (a side view of the second boss member 570). Figure 8 In order to enable air reflected by the protrusion 300 formed on the first boss member 530 to move more easily to the adjacent first boss member 530 , a groove 575 recessed from the portion of the second boss member 570 corresponding to the protrusion 300 of the adjacent first boss member 530 may be provided.

[0066] In the seventh embodiment, since the air can move to the adjacent flow channels 100 along the grooves 575 formed in the second boss member 570 , the vertical movement of the air between the flow channels 100 can be further promoted, thereby further increasing the residence time of the air.

[0067] According to the eighth embodiment of the present invention (see Fig. 9 ), the protrusion 300 formed on the first boss member 530 may protrude toward the second boss member 570 so that a portion or all of the protrusion 300 formed on the first boss member 530 is in contact with (or connected to) the second boss member 570. Fig. 9 , Fig. 9Showing the eighth embodiment of the present invention and an enlarged view (front view) of the protrusion, the protrusion 300 protrudes from the first boss member 530 toward the second boss member 570 so that the end of the protrusion 300 contacts the second boss member 570 .

[0068] In the eighth embodiment, each protrusion 300 may be provided at one point thereof with a groove 350 through which gas flows. In other words, in order to enable gas to flow through the same flow channel, a groove 350 may be provided in a portion of each protrusion 300 that contacts the first boss member 530 or the second boss member 570, so that the protrusion 300 blocks only a portion of the flow channel 100 and defines a narrow path therein.

[0069] Therefore, in the eighth embodiment, by virtue of the narrow path defined by the groove 350 formed in the protrusion, the fluidity of the air flowing through the same flow channel can be improved.

[0070] It can be clearly seen from the above description that the advantage of the separator of the embodiment of the present invention is that a vertical flow of air can be established between adjacent flow channels formed in the separator, so that the product water in the fuel cell stack can be easily discharged, and the residence time of the gas introduced into the fuel cell stack can be increased, and thereby the utilization rate of the gas can be increased, thereby improving the performance of the fuel cell stack.

[0071] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art will appreciate that the present invention may be implemented in various other embodiments without changing the technical concept or key features of the present invention.

Claims

1. A separator for a fuel cell, comprising: a plurality of flow channels configured to flow gas or product water through the separator, wherein the plurality of flow channels are provided with a plurality of protrusions protruding in a first direction and a second direction at a plurality of points, Wherein, each of the multiple flow channels is provided with a corresponding protrusion of the multiple protrusions at its set point, while an adjacent flow channel is not provided with a protrusion at the same point corresponding to the set point of the previous flow channel, and a portion of the protrusions protruding in one of the first direction and the second direction are aligned in a straight line.

2. The separator according to claim 1, wherein The shape of each of the protrusions is a streamline shape having no corners therein or an angular shape having two or more corners.

3. The separator according to claim 1, wherein The plurality of flow channels include: a first flow channel, wherein the first flow channel is provided therein with a protrusion protruding in the first direction; and A second flow channel, wherein the second flow channel is provided therein with a protrusion protruding in the second direction.

4. The separator according to claim 3, wherein The first flow channels and the second flow channels are alternately arranged.

5. The separator according to claim 4, wherein The protrusions provided in the first flow channel or the protrusions provided in the second flow channel are aligned on the one straight line.

6. The separator according to claim 1, wherein The plurality of flow channels are defined between a plurality of boss members, wherein the boss members protrude upward while extending along an extending direction of the plurality of flow channels, and wherein the boss members are spaced apart from each other.

7. The separator according to claim 6, wherein The plurality of boss members include: a first boss member on which the protrusion is formed so that the protrusion protrudes toward the flow channel; and The second boss member has no protrusion formed thereon.

8. The separator according to claim 7, wherein The first boss members and the second boss members are arranged alternately.

9. The separator according to claim 7, wherein The shape of each of the first boss members is a straight line, and the shape of each of the second boss members is a partially concave or convex streamlined shape.

10. The separator according to claim 7, wherein The first boss member and the second boss member are arranged in a gravity direction.

11. The separator according to claim 10, wherein The surface area of ​​the second boss member gradually decreases toward the ground.

12. The separator according to claim 7, wherein A groove is provided in a portion of the second boss member corresponding to the protrusion formed on the first boss member.

13. The separator according to claim 7, wherein The protrusion protrudes toward the second boss member so that a part or all of the protrusion contacts the second boss member.

14. The separator according to claim 13, wherein A portion of each of the protrusions has a groove formed therein.

15. A separator for a fuel cell, comprising: A plurality of boss members extending substantially along a gas flow direction; a plurality of flow channels formed between the plurality of boss members; protrusions extending from a first set of the boss members, the protrusions being located at a plurality of points along the flow channel and projecting into the flow channel in a first direction and a second direction, wherein the first group of protrusions extend into the first group of flow channels at the first group of points along the first direction, wherein the second group of flow channels adjacent to the first group of flow channels are not provided with any protrusions at the first group of points, wherein the second group of protrusions extend into the second group of flow channels at the second group of points along the second direction, and Wherein, the first group of flow channels are not provided with any protrusions at the second group of points.

16. The separator according to claim 15, wherein Each of the protrusions is generally in the shape of a circular protrusion, a circular trapezoid, a rectangle or a triangle.

17. The separator according to claim 15, wherein The second group of boss members are streamlined or substantially sinusoidal in shape.

18. The separator according to claim 15, wherein At least a portion of the projections extend into and contact the second set of boss members.

19. The separator according to claim 15, wherein A second set of the boss members include recesses formed therein, the recesses being positioned opposite and adjacent the protrusions.

20. A separator for a fuel cell, comprising: a first boss member extending generally along a first longitudinal direction; a second boss member extending substantially along a gas flow direction, the second boss member being separated from the first boss member by a first flow passage; a first set of projections extending from the first boss member and into the first flow channel generally in a first lateral direction generally perpendicular to the first longitudinal direction; a third boss member extending substantially along the gas flow direction, the third boss member being separated from the first boss member by a second flow passage; as well as A second set of protrusions extends from the first boss member and into the second flow channel generally along a second lateral direction generally perpendicular to the first longitudinal direction and generally opposite to the first lateral direction.

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