Stack for fuel battery and high temperature electrolysis

Abstract

One embodiment of the present invention provides a fuel cell and a stack for high-temperature water electrolysis, comprising a fuel cell having a fuel supply section and a fuel discharge section and an internal flow path, and a plurality of separator modules including a separator plate disposed on top of the fuel cell, wherein the plurality of separator modules are stacked and some of the plurality of separator modules have internal flow paths having an area different from that of the remaining portions.

Description

Technology Field

[0001] The present invention relates to a device, and more specifically to a fuel cell and a stack for high-temperature water electrolysis. Background Technology

[0002] Fuel cells and high-temperature water electrolysis stacks are attracting attention as next-generation hydrogen production technologies due to their high operating efficiency. However, problems generally exist, such as durability issues caused by high operating temperatures and performance degradation across different stack regions resulting from uneven steam and fuel supply when multiple unit stacks are stacked.

[0003] Accordingly, it is necessary to develop fuel cell and high-temperature water electrolysis stacks capable of improving the efficiency of the entire stack by uniformly supplying steam (or fuel) to each region of the cell constituting the water electrolysis or fuel cell stack, thereby inducing a uniform electrochemical reaction throughout the stack. The problem to be solved

[0004] The technical problem to be solved by the present invention is to provide a fuel cell and a high-temperature water electrolysis stack in which fuel can move in a uniform flow regardless of the stacking position of the fuel cell cells within a stack having a multilayer structure.

[0005] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0006] To achieve the above technical objective, a fuel cell and a stack for high-temperature water electrolysis according to one embodiment of the present invention comprises a fuel cell having a fuel supply section and a fuel discharge section and an internal flow path, and a plurality of separator modules including a separator plate disposed on top of the fuel cell, wherein the plurality of separator modules are stacked, and some of the plurality of separator modules may have an internal flow path having an area different from that of the remaining portions.

[0007] In an embodiment of the present invention, the stacking order of each of the plurality of separator modules can be adjusted based on a distance from at least one of the fuel supply unit and the fuel discharge unit.

[0008] In an embodiment of the present invention, a plurality of separator modules may be stacked such that the separator and the fuel cell alternately, thereby forming a separator module stacking structure.

[0009] In an embodiment of the present invention, the stacking order of each of the plurality of separator modules can be adjusted based on a distance from at least one of the fuel supply unit and the fuel discharge unit.

[0010] In an embodiment of the present invention, a separator module having an internal flow path of a relatively narrow area may be disposed at a location adjacent to either the fuel supply unit or the fuel discharge unit.

[0011] In an embodiment of the present invention, when the fuel supply unit and the fuel discharge unit are disposed at the lower end of the separator module stacking structure, a separator module having an internal flow path with a wider area than that of the lower end may be disposed at the upper end of the separator module stacking structure.

[0012] In an embodiment of the present invention, the area of ​​the internal flow path of the plurality of unit stacks can gradually increase from the bottom to the top of the separator module stacking structure.

[0013] In an embodiment of the present invention, when the fuel supply unit is positioned at the bottom of the separator module stacking structure and the fuel discharge unit is positioned at the top of the separator module stacking structure, a separator module having an internal flow path with a larger area than that of the top and bottom parts may be positioned in the middle part of the separator module stacking structure.

[0014] In an embodiment of the present invention, the area of ​​the internal flow path gradually decreases from the middle part to the upper part of the separator module stacking structure, and the area of ​​the internal flow path may gradually decrease from the middle part to the lower part of the separator module stacking structure. Effects of the invention

[0015] A fuel cell and high-temperature water electrolysis stack according to embodiments of the present invention can enable uniform fuel flow throughout the entire interior of the fuel cell and high-temperature water electrolysis stack by configuring the stack by arranging fuel cell cells having internal flow paths of different areas based on the stacking order of separator modules and distances from the fuel supply section and the fuel discharge section.

[0016] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the composition of the invention described in the description or claims of the present invention. Brief explanation of the drawing

[0017] FIG. 1 is a perspective view illustrating a fuel cell and a stack for high-temperature water electrolysis according to one embodiment of the present invention. FIG. 2 is a perspective view illustrating a state before a plurality of separator plates and a plurality of fuel cell cells are stacked according to one embodiment of the present invention. FIG. 3 is a perspective view illustrating a stacked separator module structure in which a plurality of separator plates and a plurality of fuel cell cells of FIG. 2 are stacked. FIG. 4 is a schematic cross-sectional view illustrating the interior of a conventional solid oxide fuel cell and a high-temperature water electrolysis stack. FIG. 5(a) is a cross-sectional view schematically illustrating the interior of a solid oxide fuel cell and a high-temperature water electrolysis stack according to one embodiment of the present invention, and FIG. 5(b) is a cross-sectional view schematically illustrating the interior of a solid oxide fuel cell and a high-temperature water electrolysis stack according to another embodiment of the present invention. FIG. 6 is a schematic cross-sectional view illustrating the interior of a solid oxide fuel cell and a high-temperature water electrolysis stack according to another embodiment of the present invention. Specific details for implementing the invention

[0018] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0019] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0020] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0021] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0022] FIG. 1 is a perspective view illustrating a fuel cell and a stack for high-temperature water electrolysis according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a state before a plurality of separator plates and a plurality of fuel cell cells are stacked according to an embodiment of the present invention. FIG. 3 is a perspective view illustrating a stacked separator plate module structure in which a plurality of separator plates and a plurality of fuel cell cells of FIG. 2 are stacked.

[0023] Referring to FIGS. 1 to 3, a fuel cell and high-temperature water electrolysis stack (hereinafter, fuel cell and high-temperature water electrolysis stack) (1) may include a plurality of separator modules (10a). At this time, the separator module (10a) may include a separator (100) and a fuel cell cell (200). The separator module (10a) may have a structure in which the separator (100) is stacked on the upper surface of the fuel cell cell (200).

[0024] The separator plate (100) may include a separator plate body (110), a support part (120), a first opening (130), and a second opening (140).

[0025] The separator body (110) is a portion where the first opening (130) is placed, and may have a shape corresponding to the shape of the fuel cell cell (200) stacked together with the separator (100). In the drawing, an embodiment is shown in which the separator body (110) is a plate having a thin rectangular shape or a similar shape so as to correspond to the fuel cell cell (200), but the present invention is not limited thereto.

[0026] A first opening (130) may be provided in the separator body (110). The first opening (130) may be formed by penetrating the separator body (110). More specifically, the first opening (130) may extend from the bottom of the separator body (110) to the top of the separator body (110) along the height direction (e.g., Z-axis direction) and penetrate the separator body (110). At this time, the first opening (130) may extend along the width direction (e.g., Y-axis direction) of the separator body (110). Accordingly, the first opening (130) may be an elongated through hole.

[0027] A plurality of first openings (130) may be provided. These plurality of first openings (130) may be arranged along the longitudinal direction (X-axis direction) of the separator body (110) between both ends of the separator body (110). At this time, the first openings (130) may be spaced apart from each other along the longitudinal direction (X-axis direction). Additionally, the plurality of first openings (130) may be arranged to form at least two rows. For example, the first openings (130) may be arranged to form two rows arranged side by side.

[0028] In this way, by providing a plurality of first openings (130) between both ends of the separator plate body (110), the amount of metal used in manufacturing the separator plate (100) is reduced, thereby enabling the fuel cell and high-temperature water electrolysis stack (1) to be lighter and cheaper.

[0029] The support member (120) can form a “fuel flow path (T)” together with other support members (120) provided in a plurality of separator modules (10a) that are stacked when manufacturing a fuel cell and a stack (10) for high-temperature water electrolysis. At this time, the support member (120) can be formed integrally with the separator body (110).

[0030] A second opening (140) may be provided in the support member (120). The second opening (140) may be formed by penetrating the support member (120). More specifically, the second opening (140) may extend from the bottom of the support member (120) to the top of the support member (120) along the height direction (Z-axis direction) and penetrate the support member (120). This support member (120) may extend in the width direction (Y-axis direction) of the separator plate (100).

[0031] The above-described support members (120) may be provided in pairs. These pairs of support members (120) may be placed at each end of the separator body (110). Accordingly, the pairs of support members (120) may be symmetrically arranged relative to each other with respect to the separator body (110). When a pair of support members (120) is provided in this manner, a pair of second openings (140) may also be provided, with one opening placed in each support member (120).

[0032] The fuel cell (200) may include an electrolyte layer (not shown), a fuel electrode (negative electrode) (not shown), and an air electrode (positive electrode) (not shown). Additionally, the fuel cell (200) may further include an inlet / outlet section (210) and an internal flow path (P).

[0033] The electrolyte layer (not shown) may have a dense structure so that the fuel and gas are not mixed. Also, the fuel electrode and the air electrode may be placed on both sides of the electrolyte layer. At this time, the materials constituting the electrolyte may include at least one of the ceria-based and lanthanum gallate-based materials.

[0034] The material of the fuel electrode (not shown) is a composite of one selected from nickel, nickel alloy, copper, copper alloy, and iron-based alloy and an ion-conducting electrolyte material, and the ion-conducting electrolyte material may be composed of one or more materials selected from yttria-stabilized zirconia (YSZ), scandia-stabilized zirconia (ScSZ), gadolinium-doped ceria (Gd-doped ceria, GDC), samarium-doped ceria (Sm-doped ceria), and lanthanum gallates. In addition, the material of the ion-conducting electrolyte may be one or more selected from Y (e.g., Y2O3-doped zirconia), zirconia doped with Sc or Yb, ceria doped with Y, Gd, or Sm, and LaGaO3 doped with both Sr and Mg.

[0035] The material of the air electrode (not shown) is selected from ceramics and ceramic-ion-conductive electrolyte material composites, and the ceramic is one or more selected from the group consisting of strontium titanium ferrite (STF), lanthanum strontium ferrite (LSF), lanthanum strontium cobaltite (LSC), strontium cobalt ferrite (SFC), barium strontium cobalt ferrite (BSCF), lanthanum strontium cobalt ferrite (LSCF), and lanthanum nickelate (LNO), and the ion-conductive electrolyte material is zirconia with added Y, Sc, or Yb, Y, Gd, or It may be one or more selected from ceria with Sm added and LaGaO3 with Sr and Mg simultaneously added.

[0036] The inlet / outlet section (210) may be a passage for fuel supplied from the outside to flow into the interior of the fuel cell (200), or for fuel that has passed through the interior of the fuel cell (200) (i.e., the internal flow path) (P) to be discharged to the outside of the fuel cell (200). Here, the fuel may include hydrogen (H2) and water (H2O) or high-temperature steam (H2O) as a reactant to react with oxygen ions generated through the reduction reaction of oxygen at the air electrode.

[0037] Multiple inlet / outlet sections (210) may be provided and positioned at both ends of the fuel cell (200). More specifically, multiple inlet / outlet sections (210) may be positioned at mutually corresponding locations at both ends of the fuel cell (200). Accordingly, at each end of the fuel cell (200), inlet / outlet sections (210) of the same position and number may be symmetrically positioned.

[0038] An internal flow path (P) may be formed inside the fuel cell (200). At this time, the internal flow path (P) may be formed by penetrating both ends of the fuel cell (200). That is, the internal flow path (P) may extend from one end of the fuel cell (200) to the other end located on the opposite side. This internal flow path (P) may communicate with the inlet / outlet section (210) through a plurality of moving holes (220) provided in the inlet / outlet section (210).

[0039] The separator module (10a) may be in the form of a separator (100) stacked on a fuel cell (200). At this time, the separator (100) and the fuel cell (200) may have the same or similar shape and size. When the separator (100) and the fuel cell (200) are stacked, the second opening (140) provided in the separator (100) and the inlet / outlet (210) provided in the fuel cell (200) may be positioned at corresponding locations in the vertical direction (Z-axis direction). Accordingly, at the end of the separator module (10a), a “unit flow path” in which two inlet / outlet (210) are connected may be formed on the lower surface of the second opening (140). At this time, a sealing material (300) is placed between both ends of the separator plate (100) and both ends of the fuel cell (200) to seal the space between the second opening (140) and the inlet / outlet section (210).

[0040] A plurality of separator modules (10a) may be provided. These plurality of separator modules (10a) may be stacked to form a “separator module stacking structure (10)”.

[0041] More specifically, the lower surface of a fuel cell (200) included in another separator module (10a) can be stacked so that it contacts the upper surface of a separator (100) included in one separator module (10a). In this way, a plurality of separator modules (10a) can be stacked sequentially to form the aforementioned “separator module stacking structure (10).”

[0042] In the separator module stacking structure (10), when a plurality of separator modules (10a) are stacked, the 'unit flow paths' provided in each separator module (10a) are connected along the stacking direction (up and down direction) (Z-axis direction) to form a “fuel flow path (T).”

[0043] A fuel transfer channel (T) may be formed at each end of the separator module stacking structure (10). In this case, the fuel transfer channel (T) formed at either end of the separator module stacking structure (10) may be a “fuel supply channel (T10)” connected to a fuel supply unit (S10) to be described later. And, the fuel transfer channel (T) formed at the other end of the separator module stacking structure (10) may be a “fuel discharge channel (T20)” connected to a fuel supply unit (D10) to be described later.

[0044] A sealant (300) may be placed between the stacked separator modules (10a). That is, a sealant (300) may be placed between the ends of the separator (100) of one separator module (10a) and the ends of the fuel cell (200) of another separator module (10a) stacked directly on top of the separator module (10a). The sealant (300) placed in this manner seals the spaces between the stacked multiple separator modules (10a), thereby preventing fuel passing through the fuel supply path (T10) and fuel discharge path (T20) from leaking to the outside.

[0045] FIG. 4 is a schematic cross-sectional view illustrating the interior of a conventional solid oxide fuel cell and high-temperature water electrolysis stack. FIG. 5(a) is a schematic cross-sectional view illustrating the interior of a solid oxide fuel cell and high-temperature water electrolysis stack according to one embodiment of the present invention, and FIG. 5(b) is a schematic cross-sectional view illustrating the interior of a solid oxide fuel cell and high-temperature water electrolysis stack according to another embodiment of the present invention. FIG. 6 is a schematic cross-sectional view illustrating the interior of a solid oxide fuel cell and high-temperature water electrolysis stack according to yet another embodiment of the present invention.

[0046] Referring again to FIG. 1, the fuel cell and high-temperature water electrolysis stack (1) may further include an upper manifold (20) and a lower manifold (30). Additionally, the fuel cell and high-temperature water electrolysis stack (1) may further include an upper cover (40), a lower cover (50), and an air supply unit (400).

[0047] The upper manifold (20) may be positioned at the top of the separator module stacking structure (10), and the lower manifold (30) may be positioned at the bottom of the separator module stacking structure (10). Additionally, although not shown in the drawing, an upper metal plate (not shown) may be positioned between the upper manifold (20) and the top of the separator module stacking structure (10), and a lower metal plate (not shown) may be positioned between the lower manifold (30) and the bottom of the separator module stacking structure (10).

[0048] A fuel supply unit (S10) may be provided in either the upper manifold (20) or the lower manifold (30), and a fuel supply unit (D10) may be provided in the other. For convenience of explanation, the following description focuses on an embodiment in which a fuel supply unit (S10) is provided in the lower manifold (30) and a fuel discharge unit (D10) is provided in the upper manifold (20), but the present invention is not limited thereto.

[0049] The upper cover (40) may be positioned on the upper side of the upper manifold (20). The upper cover (40) may be provided with a plurality of upper fastening holes (42). And, the lower cover (50) may be positioned on the lower side of the lower manifold (30) so as to face the upper cover (40). The lower cover (50) may be provided with a plurality of lower fastening holes (52).

[0050] In this case, the lower fastening holes (52) and the upper fastening holes (42) can be arranged to face each other. Accordingly, the lower fastening holes (52) and the upper fastening holes (42) can be arranged symmetrically in a one-to-one manner and aligned along the height direction (Z-axis direction). In this way, a second connecting member (C10) can be simultaneously inserted through the upper fastening holes (42) and the lower fastening holes (52) facing each other, and can be joined and fixed in a manner such as screw connection. Accordingly, the upper manifold (20), the separator module stacking structure (10), and the lower manifold (30) can be fixed in a stacked state between the upper cover (40) and the lower cover (50) while being pressed in the vertical direction. As a result, both ends of the stacked separator plates (100) and both ends of the fuel cell cells (200) are completely in close contact, thereby preventing the fuel moving through the fuel transfer path (T) from leaking to the outside.

[0051] The air supply unit (400) is connected to an externally positioned air supply device (not shown) to supply air to the separator module (10a). The air (oxygen) introduced through the air supply unit (400) can be supplied to the air electrode of the fuel cell cell (200).

[0052] In one embodiment, the air supply unit (400) is positioned on one side of the separator module stacking structure (10) and can spray air so as to pass from one side of a plurality of separator modules (10a) toward the other side. In another embodiment, the air supply unit (400) may be connected to an upper manifold (20) or a lower manifold (30) to supply air into the plurality of separator modules (10a).

[0053] In the fuel cell and high-temperature water electrolysis stack (1) as described above, the overall process of generating current using fuel and air supplied to the fuel cell cell (200) may be as follows.

[0054] Air can be supplied to the stacked separator module structure (10) through the air supply unit (400). More specifically, air can be injected toward the stacked separator modules (10a) through a plurality of air injection holes (not shown) provided in the air supply unit (400). By doing so, oxygen can be supplied to the air electrode of the fuel cell (200).

[0055] Additionally, fuel can be supplied to the fuel cell and the high-temperature water electrolysis stack (1) through the fuel supply unit (S10) provided in the lower manifold (30). The fuel supply unit (S10) can be connected to any one of the fuel transfer paths (hereinafter, fuel supply paths) (T). And, the fuel supply paths (T) can be connected to the transfer holes (220) of the fuel cell cells (200) constituting the stacked plurality of separator modules (10a).

[0056] Subsequently, the supplied fuel can move toward the top of the separator module stacking structure (10) through the fuel supply channel (T). As it passes through the fuel supply channel (T) and moves from the bottom to the top of the separator module stacking structure (10), some of the fuel can flow into the interior of the fuel cell (200) through the moving holes (220) provided at one end of the fuel cell (200) and flow along the internal channel.

[0057] In this process, oxygen ions generated by the reduction reaction of oxygen at the air electrode of the fuel cell (200) move to the fuel electrode through the electrolyte and react with hydrogen supplied to the fuel electrode to produce water, and at this time, electrons are generated at the fuel electrode and electrons are consumed at the air electrode, thereby connecting the two electrodes to generate an electric current.

[0058] Afterward, the fuel passing through the internal flow path of the fuel cell (200) can be discharged into the fuel discharge flow path (T) through the moving holes (220) provided at the other end of the fuel cell (200). The fuel discharged in this way can move along the fuel discharge flow path (T) toward the fuel supply unit (D10) provided in the upper manifold (20) and be discharged to the outside of the fuel cell and the high-temperature water electrolysis stack (1).

[0059] Meanwhile, referring to FIG. 4, in the case of a conventional fuel cell and high-temperature water electrolysis stack (hereinafter, conventional stack) (2), regardless of the position of the fuel supply section (S10') and the fuel discharge section (D10'), the internal flow paths (P') provided in the stacked plurality of separator modules (10b) are all configured to have the same area.

[0060] For example, when both the fuel supply unit (S10') and the fuel discharge unit (D10') are positioned at the bottom of the fuel cell and high-temperature water electrolysis stack (2), i.e., the lower manifold (not shown) [see FIG. 4 (a)], or in another example, when the fuel supply unit (S10') is positioned at the lower manifold (not shown) and the fuel discharge unit (D10') is positioned at the upper manifold (not shown) as shown in FIG. 4 (b) [see FIG. 4 (b)], the internal flow paths (P') formed inside the stacked plurality of fuel cell cells (200') are configured to have the same area.

[0061] However, when the internal channels (P') formed in the stacked structure have the same area, as such, when fuel and steam supplied to the lower manifold move from the bottom to the top of the fuel cell and high-temperature water electrolysis stack (2) of the stacked structure, the flow in the internal channels (P') located at the bottom of the fuel cell and high-temperature water electrolysis stack (2) is smooth, whereas the resistance within the internal channels (P') increases as it moves toward the top of the fuel cell and high-temperature water electrolysis stack (2). Accordingly, there is a problem in that a deviation in the flow of fuel and steam occurs between the bottom and top of the fuel cell and high-temperature water electrolysis stack (2).

[0062] Referring to FIG. 5, a fuel cell and a high-temperature water electrolysis stack (1', 1'') according to embodiments of the present invention may include various types of separator modules (10a) having internal flow paths (P) of different areas. In this case, flow deviations occurring within the stack (1', 1'') can be mitigated by adjusting the stacking order of the various types of separator modules (10a) based on the positions of the fuel supply unit (S10) and the fuel discharge unit (D10).

[0063] More specifically, in a stacked separator module structure (10) in which a plurality of separator modules (10a) are stacked, a separator module (10) having an internal flow path (P) with a large area can be placed at a stacking position relatively far from the fuel supply unit (S10) and the fuel discharge unit (D10). And, a separator module (10) having an internal flow path (P) with a narrow area can be placed at a stacking position relatively close to the fuel supply unit (S10) and the fuel discharge unit (D10). At this time, the internal flow path (P) may be provided with three or more types of flow paths having different areas, but for convenience of explanation, the following description will focus on an embodiment having two types of flow paths (P10, P20) having different areas.

[0064] In one embodiment, as illustrated in 5(a), when both the fuel supply section (S10) and the fuel discharge section (D10) are positioned at the bottom of the stack (1'), the fuel passing through the internal passages (P) descends along the fuel discharge passage (T20) toward the fuel discharge section (D10) positioned at the bottom of the stack (1). In this case, as with the conventional stack (2), if the internal passages (P') are all formed with the same area, the flow of fuel in the internal passages (P') located at the bottom near the fuel supply section (S10) and the fuel discharge section (D10) is smooth, whereas the resistance increases as it goes toward the top, causing the flow rate within the internal passages (P') to decrease.

[0065] To solve these problems, a fuel cell and a high-temperature water electrolysis stack (1') according to one embodiment of the present invention may have a first flow path (P10) having a relatively narrow area at the bottom of the stack (1) and a second flow path (P20) having a relatively wide area at the top of the stack (1'). In this case, as the flow path area at the top of the stack (1'), which is a stacking position far from the fuel supply unit (S10) and the fuel discharge unit (D10), increases, the flow rate of fuel passing through the top can increase. As a result, the flow deviation between the bottom and top of the stack (1') is reduced, so that the flow of fuel passing through all internal flow paths (P) provided in the stack (1') can be made uniform regardless of the stacking order (or stacking position) of the separator module (10a).

[0066] In addition, although not shown in the drawing, in order to further improve the uniformity of fuel flow within the fuel cell and high-temperature water electrolysis stack (1), it is also possible to construct the stack (1) by stacking separator modules (10a) such that an internal flow path (P) having the narrowest area is placed at the bottom of the stack (1), and the area of ​​the internal flow path (P) gradually increases toward the top of the stack (1), so that an internal flow path (P) having the widest area is placed at the top of the stack (1).

[0067] In another embodiment, as illustrated in FIG. 5(b), when a fuel supply unit (S10) is positioned at the bottom of the stack (1) and a fuel discharge unit (D10) is positioned at the top of the stack (1), the fuel passing through the internal passages (P) rises along the fuel discharge passage (T20) toward the fuel discharge unit (D10) positioned at the top of the stack (1'').

[0068] In this case, when the internal passages (P') are all formed with the same area as in a conventional stack (2), the flow of fuel in the internal passages (P') located at the lowest part adjacent to the fuel supply section (S10) and the upper part adjacent to the fuel discharge section (D10) is smooth, whereas the flow rate of fuel passing through the internal passages (P') decreases as it goes toward the middle part.

[0069] To solve these problems, a fuel cell and high-temperature water electrolysis stack (1'') according to another embodiment of the present invention may have a first flow path (P10) having a relatively narrow area at the bottom and top of the stack (1), and a second flow path (P20) having a relatively wide area at the middle of the stack (1''). In this case, as the flow path area at the middle of the stack (1''), which is a stacking position far from the fuel supply unit (S10) and the fuel discharge unit (D10), increases, the flow rate of fuel passing through the internal flow path, i.e., the second flow path (P20), placed at the middle of the stack (1) can increase. As a result, the flow deviation between the middle of the stack (1'') and the bottom and top is reduced, so that the flow of fuel passing through all internal flow paths (P) provided in the stack (1'') can become uniform regardless of the stacking order (or stacking position) of the separator module (10a).

[0070] In addition, although not shown in the drawing, in order to further improve the uniformity of fuel flow within the fuel cell and high-temperature water electrolysis stack (1), the stack (1) may be configured by stacking separator modules (10a) such that the area of ​​the internal flow path (P) has the narrowest area at the bottom and top of the stack (1), the area of ​​the internal flow path (P) gradually increases from the bottom of the stack (1) toward the center, the area of ​​the internal flow path (P) has the widest area at the center of the stack (1), and the area of ​​the internal flow path (P) gradually decreases from the center of the stack (1) toward the top.

[0071] Referring to FIG. 6, a large-capacity fuel cell and high-temperature water electrolysis stack (1''') can be constructed by combining fuel cell and high-temperature water electrolysis stacks (1) according to the embodiments described above. In this case as well, by arranging internal flow paths (P) having various areas based on the distance (or stacking position) from the fuel supply unit (S10) and the fuel discharge unit (D10), the fuel flow can be configured to be uniform throughout the stack (1''').

[0072] For example, as illustrated in FIG. 6, a fuel supply unit (S10) may be positioned in the center of the stack (1'''), and fuel discharge units (D10, D20) may be provided at the top and bottom of the stack (1'''), respectively. In this case, fuel supplied to the fuel supply unit (S10) may travel along two fuel supply channels (T10) connected to the fuel supply unit (S10) and extending upward and downward, and may flow into and pass through the separator modules (10a) and their internal channels (P) located in the middle of the stack (1'''). Subsequently, the fuel may be supplied to each separator module (10a) stacked at the top and bottom through the intermediate connecting channel (T20') and the intermediate supply channel (T10') connected thereto, pass through the internal channels (P), and then be discharged through the fuel discharge units (D10).

[0073] At this time, a fuel cell and high-temperature water electrolysis stack (1''') may have a first flow path (P10) with a relatively narrow area disposed at a location adjacent to the fuel supply section (S10) (i.e., the center) and at a location adjacent to the fuel discharge section (D10) (i.e., the top and bottom sections). Additionally, a second flow path (P20) with a relatively wide area may be disposed between the aforementioned center and top section of the stack (1''') and between the aforementioned center and bottom section.

[0074] Accordingly, the flow path area in the middle part of the stack (1'''), which is a stacking location far from the fuel supply unit (S10) and the fuel discharge unit (D10), is increased, so that the flow rate of fuel passing through the internal flow path, i.e., the second flow path (P20), located in the middle part of the stack (1''') can be increased. As a result, the flow deviation between the internal flow path (first flow path) (P10) located at a location adjacent to the fuel supply unit (S10) or the fuel discharge unit (D10) and the internal flow path (second flow path) (P20) located at a location far from the fuel supply unit (S10) and the fuel discharge unit (D10) is reduced, so that the flow of fuel passing through all internal flow paths (P) provided in the stack (1''') can be made uniform regardless of the stacking order (or stacking location) of the separator module (10a).

[0075] A fuel cell and high-temperature water electrolysis stack (1) according to the embodiments of the present invention as described above can be configured by arranging fuel cell cells (200) having internal flow paths (P) of different areas based on the stacking order of separator modules (10a) and distances from the fuel supply unit (S10) and the fuel discharge unit (D10), thereby enabling uniform flow of fuel throughout the interior of the fuel cell and high-temperature water electrolysis stack (1).

[0076] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0077] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0078] 1, 1', 1'', 1''': Stack for fuel cells and high-temperature water electrolysis 2: Conventional fuel cell and high-temperature water electrolysis stacks 10: Separator module stacking structure 10a: Separator module 100: Separator 200: Fuel cell 210: Inlet / Outlet 220: Moving hole S10: Fuel supply unit D10, D20: Fuel discharge section P: Internal Euro P10: First Euro P20: The 2nd Euro

Claims

Claim 1 A plurality of separator modules comprising a fuel cell having a fuel supply section and a fuel discharge section and an internal flow path for fuel movement, and a separator plate disposed on the upper part of the fuel cell; wherein the plurality of separator modules are stacked, and some of the plurality of separator modules have internal flow paths having an area different from that of the remaining parts, and the plurality of separator modules are stacked such that the separator plate and the fuel cell alternately form a separator module stacking structure, and a second opening formed at both ends of the separator plate and an inlet / outlet section formed at both ends of the fuel cell are each symmetrical according to the width direction (Y-axis direction) and length direction (X-axis direction) of the separator plate and the fuel cell, respectively, and when the separator plate and the fuel cell are stacked, each second opening formed in the separator plate overlaps and aligns with two or more inlet / outlet sections formed in adjacent fuel cells along the stacking direction (Z-axis direction) and is connected in the vertical direction to form a fuel movement path that communicates with the internal flow path. A stack for high-temperature water electrolysis that forms. Claim 2 delete Claim 3 A stack for high-temperature water electrolysis according to claim 1, wherein the stacking order of each separator module is controlled based on a distance from at least one of the fuel supply unit and the fuel discharge unit. Claim 4 A stack for high-temperature water electrolysis according to claim 3, wherein a separator module having an internal flow path of a relatively narrow area is disposed at a location adjacent to either the fuel supply unit or the fuel discharge unit. Claim 5 A stack for high-temperature water electrolysis according to claim 3, wherein when the fuel supply unit and the fuel discharge unit are disposed at the lower end of the separator module stacking structure, a separator module having an internal flow path with a wider area than the lower end is disposed at the upper end of the separator module stacking structure. Claim 6 A stack for high-temperature water electrolysis according to claim 5, wherein the area of ​​the internal flow path gradually increases from the bottom to the top of the separator module stacking structure. Claim 7 A stack for high-temperature water electrolysis according to claim 3, wherein the fuel supply unit is disposed at the lower end of the separator module stacking structure and the fuel discharge unit is disposed at the upper end of the separator module stacking structure, and a separator module having an internal flow path with a wider area than the upper end and the lower end is disposed in the middle part of the separator module stacking structure. Claim 8 A stack for high-temperature water electrolysis according to claim 7, wherein the area of ​​the internal flow path gradually decreases from the middle part to the upper part of the separator module stacking structure, and the area of ​​the internal flow path gradually decreases from the middle part to the lower part of the separator module stacking structure.

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