Manifold, and fuel cell stack and water electrolysis cell stack comprising same

Abstract

A manifold according to one embodiment of the present invention may comprise: a first thin plate having a plurality of first holes; a second thin plate which is disposed on the upper portion of the first thin plate and has a plurality of expansion holes that respectively communicate with the plurality of first holes and increase in width from the inside toward the edges; and a third thin plate which is disposed on the upper portion of the second thin plate and has a plurality of gas channel slits corresponding to the respective edges of the plurality of expansion holes.

Description

Manifold and fuel cell stack and water electrolysis cell stack including the same

[0001] The present invention relates to a manifold for distributing fuel / air gas within a stack of a solid oxide fuel cell (SOFC) or a plurality of solid oxide electrolysis cells (SOEC), and to a fuel cell stack and an electrolysis cell stack including the same.

[0002] Generally, solid oxide fuel cells (SOFCs) or solid oxide electrolysis cells (SOECs) are stacked in multiple numbers on a manifold to form a battery stack structure.

[0003] A solid oxide fuel cell or a solid oxide water electrolysis cell has a plate-shaped anode, a solid electrolyte, a cathode, and a separator, and functions as a unit cell in a battery stack structure.

[0004] Since the reaction of a solid oxide water electrolysis cell (H2O → H2 + 1 / 2O2) is the reverse reaction of a solid oxide fuel cell (H2 + 1 / 2O2 → H2O), the stacks of solid oxide fuel cells and solid oxide water electrolysis cells are mutually compatible.

[0005] In fuel cell mode, water and electric current are generated using hydrogen and oxygen, and when switched to high-temperature water electrolysis mode, hydrogen and oxygen are generated using water and electric current.

[0006] The manifold supplies hydrogen gas and oxygen gas to a solid oxide fuel cell or oxygen gas and water vapor to a solid oxide water electrolysis cell. The hydrogen gas and oxygen gas, or oxygen gas and water vapor, come into contact with the anode and cathode of the solid oxide fuel cell or the solid oxide water electrolysis cell.

[0007] The anode, solid electrolyte, and cathode generate electricity using hydrogen gas and oxygen gas in a solid oxide fuel cell, and generate hydrogen using oxygen gas and water vapor in a solid oxide water electrolysis cell.

[0008] Here, the manifold acts as a source of hydrogen gas and oxygen gas or oxygen gas and water vapor, and the membrane receives hydrogen gas and oxygen gas or oxygen gas and water vapor from the manifold and distributes them to at least one of the anode and the cathode.

[0009] Therefore, in order to maintain good performance of a solid oxide fuel cell or a solid oxide water electrolysis cell, the separator must uniformly receive hydrogen gas and oxygen gas, or oxygen gas and water vapor, from the manifold.

[0010] Conventional manifolds have gas injection pipes connected to the sides and have diffused gas based on the pressure difference within the manifold's internal space.

[0011] This method requires a large space inside the manifold and necessitates gas piping connections on the side, which leads to the problem of wasting stack space.

[0012] In Patent Document 1, gas is injected and diffused into the internal space from the side of the manifold to supply gas to the stack. This makes it difficult to modularize the stack and makes spatial density and efficient insulation of the hot box impossible.

[0013] (Patent Document 1) KR 1020240008203 A

[0014] One of the various objectives of the present invention is to provide a manifold that blocks the upward flow of gas supplied from below and diffuses it into a predetermined space so that the gas supplied to the stack is evenly diffused within the manifold.

[0015] Another of the various objectives of the present invention is to provide a fuel cell stack and a water electrolysis cell stack that are coupled to a modular lower plate or hot box communicating with a gas pipe formed at the bottom of a manifold, thereby enabling space density and efficient insulation.

[0016] A manifold according to one embodiment of the present invention may include: a first thin plate having a plurality of first holes; a second thin plate disposed on the upper part of the first thin plate and having a plurality of expansion holes that are each in communication with the plurality of first holes and widen from the inner side toward the edge; and a third thin plate disposed on the upper part of the second thin plate and having a plurality of gas channel slits corresponding to the edges of each of the plurality of expansion holes.

[0017] In addition, a manifold according to one embodiment of the present invention may further include a fourth plate disposed below the first plate and having a plurality of second holes communicating with each of the plurality of first holes.

[0018] In addition, the diameter of the plurality of second holes of the manifold according to one embodiment of the present invention may be larger than the diameter of the plurality of first holes.

[0019] In addition, the thickness of the second thin plate of the manifold according to one embodiment of the present invention may be greater than the thickness of the first thin plate and the fourth thin plate.

[0020] In addition, the plurality of first holes and the plurality of second holes of the manifold according to one embodiment of the present invention each include four, and each may be a fuel gas inlet hole, a fuel gas outlet hole, an oxygen gas inlet hole, and an oxygen gas outlet hole.

[0021] In addition, the inner side of each of the plurality of expansion holes of the manifold according to one embodiment of the present invention includes a first region that overlaps with the plurality of first holes in the stacking direction, and the edge of each of the plurality of expansion holes includes a second region that overlaps with the plurality of gas channel slits in the stacking direction, and each of the plurality of expansion holes may include a triangular shape connected from the first region to the second region by two tangents.

[0022] In addition, a plurality of guide ribs directed from the first region toward the second region may be disposed in the plurality of expansion holes of the manifold according to one embodiment of the present invention.

[0023] In addition, the guide rib of the manifold according to one embodiment of the present invention protrudes from the third thin plate and can be inserted into the interior of the expansion hole.

[0024] In addition, a manifold according to one embodiment of the present invention is [Equation 1] below,

[0025] [Equation 1] … … It can satisfy the above, where R1 is the radius of the first hole and T2 is the thickness of the second thin plate.

[0026] In addition, a fuel cell stack according to another embodiment of the present invention may include the above-described manifold; and unit cell cells repeatedly stacked on the manifold.

[0027] In addition, a water electrolysis cell stack according to another embodiment of the present invention may include the above-described manifold; and unit cell cells that are repeatedly stacked on the manifold.

[0028] According to a manifold according to an embodiment of the present invention and a fuel cell stack and a water electrolysis cell stack including the same, gas supplied from the lower part of the manifold and uniformly diffused gas can be provided to the stack part through a slit at the upper part of the manifold.

[0029] In addition, since gas is supplied from the bottom, the fuel cell stack can be modularized, making it easy to assemble into hot boxes or lower piping, and enabling space saving and efficient insulation.

[0030] FIG. 1 is a schematic perspective view of a fuel cell stack in one embodiment of the present invention.

[0031] Figure 2 is a cross-sectional view of I-I' in Figure 1.

[0032] FIG. 3 is a schematic perspective view of a manifold according to one embodiment of the present invention.

[0033] Fig. 4 is an exploded perspective view of Fig. 3.

[0034] FIGS. 5(a) to 5(d) are plan views of each thin plate of FIG. 3 in plan.

[0035] FIG. 6 is a schematic plan view according to another embodiment of the present invention.

[0036] FIG. 7 is a schematic perspective view illustrating the combination of the first thin plate and the second thin plate.

[0037] Figure 8 is a schematic diagram illustrating the installation of a modularized fuel cell stack in a hot box.

[0038] Figure 9 is a schematic diagram illustrating a modularized fuel cell stack installed in a lower-type pipe.

[0039] Some of the drawings are included as schematics. The drawings are illustrated for illustrative purposes only and should not be considered as drawn to actual scale. Additionally, drawings as schematics are provided to aid understanding and may not include all aspects or information compared to realistic representations, and may include exaggerated information.

[0040] Embodiments of the present invention may be modified in various different forms and are provided to explain more completely to those with average knowledge in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clarity, and elements indicated by the same reference numeral in the drawings refer to the same elements.

[0041] In the present invention, expressions such as "side" and "side" are used for convenience to refer to the left / right direction or the surface in that direction based on the drawings; expressions such as "upper side," "upper," and "upper surface" are used for convenience to refer to the upward direction or the surface in that direction based on the drawings; and expressions such as "lower side," "lower," and "lower surface" are used for convenience to refer to the downward direction or the surface in that direction. Furthermore, the concept of being located on the side, upper side, upper, lower side, or lower side is used to include not only cases where the subject component is in direct contact with the reference component in the corresponding direction, but also cases where it is located in the corresponding direction but does not make direct contact. However, this is a definition of direction for the convenience of explanation, and the scope of the patent claims is not specifically limited by such description of directions, and the concepts of upper / lower, etc., may change at any time.

[0042] In the present invention, the meaning of "connection" is a concept that includes not only "directly connected" but also "indirectly connected" through other configurations. Furthermore, depending on the case, it is a concept that includes all "electrically connected" components.

[0043] In the present invention, expressions such as "first," "second," etc., are used to distinguish one component from another and do not limit the order and / or importance of said components. In some cases, without departing from the scope of the rights, the first component may be named the second component, and similarly, the second component may be named the first component.

[0044] The expression "an example" as used in this invention does not imply identical embodiments, but is provided to emphasize and describe distinct features of each. However, the examples presented above do not exclude implementation in combination with features of other examples. For example, even if a matter described in a specific example is not described in another example, it may be understood as a description related to that other example, provided that there is no description in that other example that contradicts or conflicts with such matter.

[0045] The expression "substantially identical" used in this invention does not mean complete identity, but rather means identical including process errors, positional deviations, and measurement errors that occur during the manufacturing process.

[0046] The terms used in this invention are for illustrative purposes only and are not intended to limit the invention. In this context, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0047] The present invention will be described below with reference to the attached drawings. In the drawings, the shapes and sizes of the elements may be exaggerated or reduced for clearer explanation.

[0048]

[0049] Fuel cell stack / Electrolyze cell stack

[0050] FIG. 1 is a schematic perspective view of a fuel cell stack in one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along I-I' of FIG. 1.

[0051] Referring to FIGS. 1 and 2, in one embodiment of the present invention, a fuel cell stack or water electrolysis cell stack (1) includes a manifold (10), a stack section (20), and an end plate (40).

[0052] The following description explains a fuel cell stack as an example, and the water electrolysis stack can be understood as the reverse reaction of the fuel cell stack. In the water electrolysis stack, the fuel is water vapor, and at the fuel electrode, the water vapor is decomposed into hydrogen, and the oxygen ions produced by water electrolysis move through the electrolyte layer to the air electrode. Electrons are supplied from externally applied power to generate oxygen.

[0053] The manifold (10) of the embodiments of the present invention described below is applicable to both fuel cell stacks and water electrolysis cells.

[0054] The stack portion (20) can be configured by repeatedly stacking a separator plate (22) and a unit cell frame (25) on the upper part of the manifold (10).

[0055] A sealing layer (24) that adjusts the height to form a fuel gas passage and an air passage may be placed between the separator (22) and the unit cell frame (25).

[0056] The manifold (10) and the end plate (40) can be placed at the bottom and top of the stack section (20), respectively.

[0057] The manifold (10) supplies fuel and gas to the stack section (20), collects the remaining reaction gas, and discharges it to the outside, and the end plate (40) pressurizes the stack section (20) to apply a constant surface pressure. In addition, current can be applied to the unit cell (250) within the stack section (20) using a current terminal (not shown).

[0058] A unit cell (250) disposed in a unit cell frame (25) comprises an electrolyte support layer (255), a fuel electrode (252) disposed on the lower surface of the electrolyte support layer (255), and an air electrode (254) disposed on the upper surface of the electrolyte support layer (255). The electrolyte support layer (255) is made of a solid oxide with a dense structure that does not allow gas to pass through.

[0059] On one side of the separator plate (22) facing the fuel electrode (252), a gas channel hole for supplying fuel (hydrogen gas) to the fuel electrode (252) is located, and on the separator plate (22) facing the air electrode (254), an air channel hole for supplying air (oxygen gas) may be located.

[0060] When air is supplied to the air electrode (254) and fuel (hydrogen) is supplied to the fuel electrode (252), oxygen generated by the reduction reaction of oxygen at the air electrode (254) moves to the fuel electrode (252) through the electrolyte support layer (255) and reacts with the hydrogen supplied to the fuel electrode (252) to produce water.

[0061] At this time, electrons generated at the fuel electrode (252) are transferred to the air electrode (254) and consumed, and electrons flow into the external circuit, and the unit cell (250) produces electrical energy using this flow of electrons.

[0062] Fuel (hydrogen gas) and air (oxygen gas) are supplied and discharged through separate channels throughout the solid oxide fuel cell stack (1).

[0063] In the manifold (10), two types of gases, fuel (hydrogen gas) and air (oxygen gas), are supplied and discharged through channel holes formed therein, and in the embodiment of the present invention, hydrogen and oxygen gases are supplied from the lower part of the manifold to facilitate modularization.

[0064]

[0065] Hereinafter, a manifold according to one embodiment of the present invention will be described in detail.

[0066] manifold

[0067] FIG. 3 is a schematic perspective view of a manifold according to one embodiment of the present invention, FIG. 4 is an exploded perspective view of FIG. 3, and FIG. 5(a) to FIG. 5(d) are plan views showing each thin plate of FIG. 3 in a plan view.

[0068] Referring to FIGS. 3 to 5, a manifold (10) according to one embodiment of the present invention includes a structure in which a first thin plate (120), a second thin plate (140), and a third thin plate (160) are laminated.

[0069] The first thin plate (120) may have a plurality of first holes (122, 124). In this embodiment, four holes are formed, and fuel gas and oxygen gas flow into the plurality of first holes (122, 124) from the lower part of the manifold (10) and are transmitted to the stack portion (20).

[0070] In addition, the reaction gas remaining after passing through the stack section (20) is discharged downward through each flow path hole of the manifold (10).

[0071] The second thin plate (140) is placed on the upper part of the first thin plate (120) and may be provided with a plurality of expansion holes (142, 144) that are connected to a plurality of first holes (122, 124) of the first thin plate (120) and widen from the inner side toward the edge.

[0072] Additionally, the third thin plate (160) is positioned on top of the second thin plate (140) and may be provided with a plurality of gas channel slits (162, 164) corresponding to the edges of each of the plurality of expansion holes (142, 144) of the second thin plate (140).

[0073] Meanwhile, the manifold (10) may further include a fourth plate (150) which is positioned at the bottom of the first plate (120) and has a plurality of second holes (152, 154) communicating with each of the plurality of first holes (122, 124).

[0074] The plurality of first holes (122, 124) of the first thin plate (120) and the plurality of second holes (152, 154) of the fourth thin plate (150) each include four, and each may be a fuel gas inlet hole, a fuel gas outlet hole, an oxygen gas inlet hole, and an oxygen gas outlet hole.

[0075] The diameter of the plurality of second holes (152, 154) of the fourth plate (150) may be larger than the diameter of the plurality of first holes (122, 124) of the first plate (120). Thus, the fourth plate (150) can guide the connection with the first plate (120) when the lower reaction gas pipe is inserted.

[0076] Additionally, the centers of the multiple second holes (152, 154) of the fourth sheet (150) can be aligned with the centers of the multiple first holes (122, 124) of the first sheet (120).

[0077] Meanwhile, the thickness of the second thin plate (140) having a plurality of expansion holes (142, 144) formed therein may be greater than the sum of the thicknesses of the first thin plate (120) and the fourth thin plate (150). For example, the thickness of the first thin plate (120) may be about 3 mm to 4 mm, the thickness of the fourth thin plate (150) may be about 5 mm to 10 mm, and the thickness of the second thin plate (140) may be about 15 mm.

[0078] The thickness of the second thin plate (140) can facilitate the flow of gas entering from the bottom.

[0079] FIG. 6 is a schematic plan view according to another embodiment of the present invention.

[0080] Referring to FIG. 6, the inner side of each of the plurality of expansion holes (142, 144) of the second thin plate (140) includes a first region (220) that overlaps with the plurality of first holes (122, 124) of the first thin plate (120) in the stacking direction, and the edge of each of the plurality of expansion holes (142, 144) may include a second region (240) that overlaps with the plurality of gas channel slits (162, 164) of the third thin plate (160) in the stacking direction.

[0081] Here, the first region (220) substantially corresponds to the region of the plurality of first holes (122, 124) of the first sheet (120), and the second region substantially corresponds to the region of the plurality of gas channel slits (162, 164) of the third sheet (160).

[0082] Additionally, each of the multiple expansion holes (142, 144) may include a triangular shape connected from the first region (220) to the second region (240) by two tangents (222, 224).

[0083] Meanwhile, a plurality of guide ribs (225) extending from the first region (220) to the second region (240) may be arranged in the plurality of expansion holes (142, 144) of the second sheet (140).

[0084] Here, the guide rib (225) protrudes downward from the third sheet (160) and can be inserted into the expansion holes (142, 144) of the second sheet (140).

[0085] Gas flow in the multiple expansion holes (142, 144) of the second thin plate (140) is blocked from moving upward by the third thin plate and spreads to the gas channel slits (162, 164) of the third thin plate (160) by the triangular expansion holes (142, 144) and guide ribs (225).

[0086] A uniform gas diffused through a plurality of expansion holes (142, 144) via the gas channel slits (162, 164) of the third thin plate (160) is supplied to the stack portion (20).

[0087] FIG. 7 is a schematic perspective view illustrating the combination of the first thin plate and the second thin plate.

[0088] Referring to FIG. 7, the inlet area (A1) of the gas flow rate entering through the first hole (122, 124) of the first thin plate (120) and the minimum inlet area (A2) of the gas entering through the expansion hole (142, 144) are shown.

[0089] A1 is the area of ​​the first hole (122, 124) of the first thin plate (120), A2 is the minimum inlet area (A) of the gas flowing into the expansion hole (142, 144), and is the product (D×T2) of the diameter (D) of the first hole (122, 124) and the thickness (T2) of the second thin plate (140).

[0090] The relationship between these A1 and A2 satisfies [Equation 1] below.

[0091] [Equation 1] … …

[0092] Here, R1 is the radius of the first hole, and T2 is the thickness of the second thin plate.

[0093] In other words, since A2 is larger than A1, the gas flow can move stably from the bottom to the top.

[0094] FIG. 8 is a schematic diagram showing a modular fuel cell stack installed in a hot box, and FIG. 9 is a schematic diagram showing a modular fuel cell stack installed in a bottom-type pipe.

[0095] Referring to FIG. 8, a fuel cell stack (1) having a manifold (10) with gas inlet holes and gas outlet holes formed in the lower part, as in the embodiment described above, is installed in a hot box (2).

[0096] The fuel cell stack (1) is installed within a common outer casing called a "hotbox" and can be thermally integrated with other components of the fuel cell power generation system (e.g., one or more anode tail gas oxidizers, fuel reformers, fuel conduits and manifolds, etc.).

[0097] The gas supply pipe (4) installed at the bottom of the hot box (2) can be easily installed by inserting the gas inlet hole and gas outlet hole formed at the bottom of the manifold (10) of the fuel cell stack (1).

[0098] Referring to FIG. 9, a fuel cell stack (1) having a manifold (10) with gas inlet holes and gas outlet holes formed in the lower part, as in the above-described embodiment, is installed in a lower pipe (5).

[0099] It can be easily installed by inserting it into the gas supply pipe (4) of the lower type pipe (5).

[0100] The lower connection method shown in FIGS. 8 and 9 can save space and be compact compared to the method in which the gas supply pipe (4) is connected from the side of the manifold (10).

[0101]

[0102] The invention disclosed herein is not limited by the embodiments described above and the accompanying drawings, but is limited by the appended claims. Accordingly, various substitutions, modifications, and changes may be made by those skilled in the art without departing from the technical spirit of the invention as described in the claims, and such are also to be considered to fall within the scope of the invention.

[0103]

[0104] (Explanation of symbols)

[0105] 1: Fuel cell stack / Electrolyze cell stack

[0106] 10: Manifold

[0107] 120: First Plate 140: Second Plate

[0108] 160: Third Plate 150: Fourth Plate

[0109] 142, 144: Expansion Hall 220: First Area

[0110] 240: Second Zone

Claims

1. A first thin plate having a plurality of first holes; A second thin plate disposed on the upper portion of the first thin plate and having a plurality of expansion holes that are each in communication with the plurality of first holes and widen in width from the inside toward the edge; and A manifold comprising: a third thin plate disposed on the upper portion of the second thin plate and having a plurality of gas channel slits corresponding to the edges of each of the plurality of expansion holes.

2. In Paragraph 1, A manifold further comprising: a fourth plate disposed below the first plate and having a plurality of second holes communicating with each of the plurality of first holes.

3. In Paragraph 2, A manifold in which the diameter of the plurality of second holes is larger than the diameter of the plurality of first holes.

4. In Paragraph 2, A manifold in which the thickness of the second thin plate is greater than the thickness of the first thin plate and the fourth thin plate.

5. In Paragraph 2, The plurality of first holes and the plurality of second holes each include four, A manifold, each having a fuel gas inlet hole, a fuel gas outlet hole, an oxygen gas inlet hole, and an oxygen gas outlet hole.

6. In Paragraph 1, The inner side of each of the plurality of expansion holes includes a first region that overlaps with the plurality of first holes in the stacking direction, and the edge of each of the plurality of expansion holes includes a second region that overlaps with the plurality of gas channel slits in the stacking direction. A manifold in which each of the plurality of expansion holes comprises a triangular shape connected by two tangents from the first region to the second region.

7. In Paragraph 6, A manifold in which a plurality of guide ribs facing from the first region to the second region are disposed in the plurality of expansion holes.

8. In Paragraph 7, The above guide rib protrudes from the third thin plate and is a manifold inserted into the expansion hole.

9. In Paragraph 1, Below [Equation 1], [Equation 1] … … Satisfying, Here, R1 is the radius of the first hole and T2 is the thickness of the second thin plate in the manifold.

10. A manifold conforming to any one of paragraphs 1 through 9; and A fuel cell stack comprising unit cell cells repeatedly stacked on the above manifold.

11. A manifold conforming to any one of paragraphs 1 through 9; and A water electrolysis cell stack comprising unit cell cells repeatedly stacked on the above manifold.

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