Fuel cell unit

Abstract

When viewing the fuel cell unit (100) in a planar manner from the side of the auxiliary device (30), the area enclosed by the outer edge of the first auxiliary device (30A) is designated as Area A, the area enclosed by the outer edge of the fuel cell stack (10) is designated as Area B1, the area enclosed by the outer edge of the power converter (20) is designated as Area B2, and the area formed by summing Area B1 and Area B2 is designated as Area B3. Area A overlaps with at least a portion of Area B1 and at least a portion of Area B2. The entirety of Area A is contained within the inner side of Area B3.

Description

Technology Field

[0001] The present disclosure relates to a fuel cell unit. Background Technology

[0002] A fuel cell is a battery that generates electrical energy through a chemical reaction between an oxidant gas containing oxygen and a fuel gas containing hydrogen. A cell (single cell), which serves as the basic unit of a fuel cell (fuel cell stack), generally comprises a Membrane Electrode Assembly (MEA) in which electrode catalyst layers are formed on both sides of a solid polymer electrolyte membrane. A Gas Diffusion Layer (GDL) is disposed on the outer side of the MEA. A separator having a gas flow path is disposed on the outer side of the Gas Diffusion Layer.

[0003] In addition, the fuel cell unit comprises at least a fuel cell stack and a power converter. Furthermore, the fuel cell unit typically comprises an auxiliary device that assists in the operation of the fuel cell. For example, in the fuel cell unit disclosed in Japanese Patent Publication No. 2017-135093, a converter in which the arrangement of reactors is approximately parallel to the stacking direction of the single cell is disposed above or below the fuel cell stack. The problem to be solved

[0004] When a fuel cell unit is mounted, for example, in a fuel cell vehicle (FCEV), it is desirable that the fuel cell unit has good installability. The present disclosure provides a fuel cell unit with good installability. means of solving the problem

[0005] A fuel cell unit according to the present disclosure comprises a fuel cell stack, a power converter configured to convert the power of the fuel cell stack, and at least a first auxiliary device configured to assist in the operation of the fuel cell stack. The power converter is disposed on a first surface of the fuel cell stack. The auxiliary device is connected to a second surface of the fuel cell stack through a stack manifold. The normal direction of the first surface and the normal direction of the second surface intersect. When viewing the fuel cell unit in a plane from the side of the auxiliary device, the area enclosed by the outer edge of the first auxiliary device is designated as Area A, the area enclosed by the outer edge of the fuel cell stack is designated as Area B1, the area enclosed by the outer edge of the power converter is designated as Area B2, and the area formed by summing Area B1 and Area B2 is designated as Area B3. Area A overlaps with at least a portion of Area B1 and at least a portion of Area B2, and the entirety of Area A is contained within Area B3.

[0006] The above fuel cell unit may have a second auxiliary device as the auxiliary device. If, when viewed from the above plane, the area enclosed by the outer edge of the second auxiliary device is defined as area C, the entirety of area C may be contained within either area B1 or area B2.

[0007] The above fuel cell unit does not need to have an auxiliary device protruding from area B3 as the auxiliary device.

[0008] The first auxiliary device above may be at least one of a gas-liquid separator, a humidifier, and an ejector.

[0009] The above fuel cell unit may have a converter and an inverter as the power converter. The converter and the inverter may be arranged in sequence on the first side.

[0010] For the entirety of the fuel cell unit, the ratio of the portion of the region A that overlaps with the region B1 may be 50% or more.

[0011] For the entirety of the fuel cell unit, the ratio of the portion of the region A that overlaps with the region B2 may be 50% or more.

[0012] In the present disclosure, the effect of being able to provide a fuel cell unit with good mounting capability is achieved.

[0013] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which similar elements are indicated by similar reference numerals. Brief explanation of the drawing

[0014] FIG. 1a is a schematic plan view of a fuel cell unit according to the present disclosure, viewed in plan from the auxiliary device side. FIG. 1b is a schematic plan view of a fuel cell unit according to the present disclosure, viewed from the left-right direction of the ground in FIG. 1a. FIG. 2a is a schematic plan view of a fuel cell unit of a comparative example seen in plan from the auxiliary device side. FIG. 2b is a schematic plan view of a fuel cell unit of a comparative example seen from the left-right direction of the ground in FIG. 2a. FIG. 3 is a schematic plan view illustrating a fuel cell unit according to the present disclosure. FIG. 4 is a schematic plan view illustrating a fuel cell unit according to the present disclosure. FIG. 5a is a schematic plan view illustrating a fuel cell unit according to the present disclosure. FIG. 5b is a schematic plan view illustrating a fuel cell unit according to the present disclosure. FIG. 6a is a schematic cross-sectional view illustrating a fuel cell stack according to the present disclosure. FIG. 6b is a schematic cross-sectional view illustrating a single cell in the present disclosure. FIG. 7a is a schematic plan view illustrating a fuel cell unit according to the present disclosure. FIG. 7b is a schematic plan view illustrating a fuel cell unit according to the present disclosure. Specific details for implementing the invention

[0015] Hereinafter, the fuel cell unit of the present disclosure will be described in detail. Each drawing shown below is schematically illustrated, and the size and shape of each part are appropriately exaggerated to facilitate understanding. Furthermore, in the present specification, when describing an arrangement of another member relative to a certain member, if simply indicated as "above" or "below," unless otherwise specified, it includes both cases: the case where another member is placed directly above or below a certain member in contact with it, and the case where another member is placed above or below a certain member through a separate member.

[0016] FIGS. 1a and 1b are schematic plan views illustrating a fuel cell unit according to the present disclosure. FIG. 1a is a plan view of the fuel cell unit viewed from the side of the auxiliary device. FIG. 1b is a plan view of the fuel cell unit viewed from the left-right direction of FIG. 1a. As illustrated in FIGS. 1a and 1b, the fuel cell unit (100) has a fuel cell stack (10), a power converter (20) that converts the power of the fuel cell stack (10), and an auxiliary device (30) that assists in the operation of the fuel cell stack (10). Also, as illustrated in FIGS. 1a and 1b, the power converter (20) is positioned on a first surface X of the fuel cell stack (10). The auxiliary device (30) is connected to a second surface Y of the fuel cell stack (10) through a stack manifold (not illustrated). Additionally, as shown in FIG. 1b, the normal direction M of the first surface X and the normal direction N of the second surface Y intersect. Furthermore, the fuel cell unit (100) has a first auxiliary device (30A) as an auxiliary device (30). Also, as shown in FIG. 1a, when the fuel cell unit (100) is viewed as a plane from the side of the auxiliary device (30), the area enclosed by the outer edge of the first auxiliary device (30A) is designated as area A, the area enclosed by the outer edge of the fuel cell stack (10) is designated as area B1, the area enclosed by the outer edge of the power converter (20) is designated as area B2, and the area formed by summing area B1 and area B2 is designated as area B3, then area A overlaps with at least a part of area B1 and at least a part of area B2, and the entire area of ​​area A is contained within the inner side of area B3.

[0017] According to the present disclosure, when the fuel cell unit (100) is viewed in a planar manner from the side of the auxiliary device (30), the region A enclosed by the outer edge of the first auxiliary device (30A) overlaps with at least a part of the region B1 enclosed by the outer edge of the fuel cell stack (10) and at least a part of the region B2 enclosed by the outer edge of the power converter (20), and furthermore, the entire region A is included within the inner side of the region B3, which is the sum of the regions B1 and B2. Because of this, the fuel cell unit (100) has good mounting capabilities.

[0018] The effect of the fuel cell stack (10) in the present disclosure is explained using FIGS. 2a and 2b. FIGS. 2a is a plan view corresponding to FIGS. 1a, and FIGS. 2b is a plan view corresponding to FIGS. 1b. As shown in FIGS. 2a and 2b, when an auxiliary device (30) protrudes from the fuel cell stack (10) and the power converter (20), extra space is required to mount the fuel cell stack, as indicated by the dotted line in the drawing, and thus the mounting capability is deteriorated. In contrast, in the fuel cell unit of the present disclosure, as shown in FIG. 1a, the entire area A enclosed by the outer edge of the first auxiliary device (30A) is included within the area B3, which is the sum of the area B1 enclosed by the outer edge of the fuel cell stack (10) and the area B2 enclosed by the outer edge of the power converter (20). Therefore, the mounting capability of the fuel cell unit (100) can be improved.

[0019] Here, the fuel cell stack (10) and the power converter (20) are typically housed in the fuel cell case and the power converter case, respectively. Accordingly, in the present disclosure, region B1 can be understood as a region enclosed by the outer edge of the fuel cell case. Likewise, region B2 can be understood as a region enclosed by the outer edge of the power converter case. Furthermore, in the present disclosure, the "inner" of the region also includes the outer edge portion of the region.

[0020] As illustrated in FIG. 1a and FIG. 1b, the power converter (20) in the present disclosure is positioned on a first surface X of a fuel cell stack (10). The normal direction M of the first surface X may be parallel to the stacking direction D (Fig. 6a) of the fuel cell (single cell) described later, or it may be orthogonal to the stacking direction D of the single cell. Additionally, the first surface X of the fuel cell stack (10) is preferably the lower surface in the direction of gravity of the fuel cell stack (10). Here, in the present disclosure, "parallel" includes not only strictly parallel but also cases where the angle formed by the two directions is 10° or less. The angle may be 5° or less. Additionally, in the present disclosure, "orthogonal" includes not only strictly orthogonal but also cases where the angle formed by the two directions is 80° or more and 100° or less. The angle may be 85° or more and 95° or less.

[0021] As illustrated in FIGS. 1a and 1b, the auxiliary device (30) in the present disclosure is connected to the second surface Y of the fuel cell stack (10). The normal direction N of the second surface Y may be parallel to the stacking direction D of the fuel cell (single cell) described later, or it may be orthogonal to the stacking direction D of the single cell. "Parallel" and "orthogonal" are as described above. In addition, the normal direction M of the first surface X and the normal direction N of the second surface Y intersect. The normal direction M and the normal direction N may be orthogonal or not orthogonal, but it is preferable that they be orthogonal. "Orthogonal" is as described above.

[0022] The fuel cell unit (100) in the present disclosure has a first auxiliary device (30A) as an auxiliary device (30). For the first auxiliary device (30A), region A overlaps with at least a part of region B1 and at least a part of region B2. For example, as shown in FIG. 1a, the ratio of the portion of region A that overlaps with region B1 with respect to the entire region A may be 50% or more. Meanwhile, as shown in FIG. 3, the ratio of the portion of region A that overlaps with region B2 with respect to the entire region A may be 50% or more. Also, the ratio of the portion of region B1 that overlaps with region A with respect to the entire region B1 may be, for example, 5% or more and 10% or more. Meanwhile, the ratio of the portion of region B1 that overlaps with region A with respect to the entire region B1 may be 100% or less, 70% or less, or 50% or less. For the entirety of region B2, the proportion of the portion of region B2 that overlaps with region A is the same as that of the aforementioned region B1.

[0023] In addition, regarding the first auxiliary device (30A) in the present disclosure, the entirety of region A is included within region B3. The ratio of the portion of region B3 that overlaps with region A to the entirety of region B3 is, for example, 5% or more, 10% or more, or 30% or more. Meanwhile, the ratio of the portion of region B3 that overlaps with region A to the entirety of region B3 is, for example, 90% or less, 70% or less, or 50% or less.

[0024] Additionally, as illustrated in FIG. 1a, when viewed from the plane, the first auxiliary device (30A) may be extended in the normal direction M of the first surface X of the fuel cell stack (10). Meanwhile, as illustrated in FIG. 4, when viewed from the plane, the first auxiliary device (30A) may be extended in a direction that intersects the normal direction M of the first surface X of the fuel cell stack (10). The intersection may be orthogonal or not orthogonal. Orthogonality is as described above. Additionally, when viewed from the plane, the shape of the first auxiliary device (30A) (the plane shape of area A) may be a square such as a square or a rectangle, a polygonal shape such as a triangle, a circular shape such as a circle or an ellipse, or a shape that is a combination of a polygonal shape and a circular shape. Furthermore, the "polygonal shape" includes not only strict polygons but also shapes in which parts corresponding to the corners of the polygon are formed in an arc shape.

[0025] FIGS. 5a and 5b are schematic plan views illustrating a fuel cell unit (100) according to the present disclosure, and are plans of the fuel cell unit (100) viewed from the side of an auxiliary device not shown. As shown in FIG. 5a, in the fuel cell unit (100), the width W1 of region B1 and the width W2 of region B2 may be the same. On the other hand, as shown in FIG. 5b, in the fuel cell unit (100), the width W1 of region B1 and the width W2 of region B2 may be different. "Same" means that the W2 / W1 described below is 0.95 or more and 1.05 or less. When the width W1 and the width W2 are different, the ratio of W2 to W1 (W2 / W1) may be, for example, 0.5 or more, 0.7 or more, or 0.9 or more. On the other hand, W2 / W1 is, for example, 1.2 or less. Here, “width W1” refers to the length of the first surface X of the fuel cell stack (10) when the fuel cell unit (100) is viewed in a planar view from the auxiliary device side, as shown in FIGS. 5a and 5b. Also, “width W2” refers to the length of the surface Z of the power converter (20) opposite to the first surface X of the fuel cell stack (10) when the fuel cell unit (100) is viewed in a planar view from the auxiliary device side.

[0026] Additionally, as illustrated in FIGS. 5a and 5b, the shapes (planar shapes) of regions B1 and B2 may each be squares. The term "square" includes not only strict squares but also shapes in which the portions corresponding to the corners of the square are formed in an arc shape. Furthermore, the planar shape of region B3 may be square as illustrated in FIG. 5a, or it may be a convex shape as illustrated in FIG. 5b. The term "convex shape" includes not only the strict convex shape of FIG. 5b but also shapes in which the portions corresponding to the corners of the convex shape are formed in an arc shape.

[0027] 1. Fuel cell stack

[0028] FIGS. 6a and 6b are schematic cross-sectional views illustrating a fuel cell stack (10) and a fuel cell (single cell (40)) according to the present disclosure. As shown in FIG. 6a, the fuel cell stack (10) according to the present disclosure typically has a stacked structure in which a plurality of single cells (40) are stacked. The number of single cells (40) (stacked number) is typically 2 or more, may be 5 or more, or 10 or more. As described above, the stacking direction D of the plurality of single cells (40) may be parallel to or orthogonal to the normal direction M of the first surface X of the fuel cell stack (10) shown in FIG. 1a, etc. Additionally, the stacking direction D of the plurality of single cells (40) may be parallel to or orthogonal to the normal direction N of the second surface Y of the fuel cell stack (10) shown in FIG. 1b, etc. In addition, as shown in FIG. 6a, it is preferable that the surface of the fuel cell stack (10) at the end of the stacking direction D of the single cell (40) is the second surface Y.

[0029] Additionally, as illustrated in FIG. 6a, the fuel cell stack (10) in the present disclosure is housed in a fuel cell case (50). The fuel cell case (50) has an opening formed therein for electrically connecting the fuel cell stack (10) (e.g., FIG. 1a) and the power converter (20) (e.g., FIG. 1a). The material of the fuel cell case (50) is not particularly limited and can be made of various materials.

[0030] The shape of the fuel cell stack (10) is preferably a rectangular prism shape as a whole. The "rectangular prism shape" includes not only a strict rectangular prism but also a shape that can approximate a rectangular prism shape. Additionally, the shape of the fuel cell stack (10) may be understood as the shape of the fuel cell case (50).

[0031] As shown in FIG. 6b, the fuel cell (single cell) (40) has a membrane-electrode assembly (MEA) (46) in which a cathode-side gas diffusion layer (41), a cathode catalyst layer (42), an electrolyte membrane (43), an anode catalyst layer (44), and an anode-side gas diffusion layer (45) are stacked in this order, and two separators (47, 48) that support the MEA (46).

[0032] As for the electrolyte membrane (43), examples include a fluorine-based electrolyte membrane such as a perfluorosulfonic acid membrane and a non-fluorine-based electrolyte membrane. As for the non-fluorine-based electrolyte membrane, examples include a hydrocarbon-based electrolyte membrane. The thickness of the electrolyte membrane (43) is, for example, 5 μm or more and 100 μm or less.

[0033] The cathode catalyst layer (42) and the anode catalyst layer (44) comprise, for example, a catalyst metal that promotes an electrochemical reaction, a base material that supports the catalyst metal, an electrolyte having proton conductivity, and carbon particles having electron conductivity. Examples of catalyst metals include, for example, a single metal such as Pt (platinum) or Ru (ruthenium), or an alloy containing Pt. Examples of electrolytes include fluorine-based resins. Additionally, examples of carbon materials such as carbon can be used as the base material and the conductive material. The thickness of the cathode catalyst layer (42) and the anode catalyst layer (44) is, for example, 5 μm or more and 100 μm or less, respectively.

[0034] The anode-side gas diffusion layer (45) and the cathode-side gas diffusion layer (41) may be conductive materials having gas permeability. Examples of conductive materials include carbon porous materials such as carbon cloth and carbon paper, and metal porous materials such as metal mesh and foamed metal. The thickness of the anode-side gas diffusion layer (45) and the cathode-side gas diffusion layer (41) is, for example, 5 μm or more and 100 μm or less, respectively.

[0035] The separator (47) may have a gas path on the surface facing the cathode-side gas diffusion layer (41). The separator (48) may have a gas path on the surface facing the anode-side gas diffusion layer (45). For the materials of the separators (47, 48), metal materials such as stainless steel and carbon materials such as carbon composite materials may be used. In addition, these separators (47, 48) have electronic conductivity and also function as current collectors for generated electricity.

[0036] 2. Power converter

[0037] The position of the power converter (20) in the present disclosure is as described above. In addition, the power converter (20) in the present disclosure is typically housed in a power converter case. The power converter case typically has an opening formed therein for electrically connecting the fuel cell stack (10) and the power converter (20). The material of the power converter case is not particularly limited and can be made of various materials.

[0038] The power converter (20) is not particularly limited as long as it is a component that converts the power of the fuel cell stack (10). The power converter (20) may be a converter such as a boost converter, a step-down converter, or a step-down converter capable of both boosting and stepping down, or it may be an inverter that converts DC power into AC power. Additionally, the fuel cell unit (100) may have one of the above devices as the power converter (20), or may have two or more. For example, when the fuel cell unit (100) has a converter and an inverter as the power converter (20), it is preferable that the converter and the inverter be arranged in order on the first side X. This allows the electricity generated from the fuel cell stack (10) to flow to the converter and the inverter without diverting it, and improves the mounting capability of the fuel cell unit (100).

[0039] 3. Assistive devices

[0040] The auxiliary device (30) in the present disclosure is connected to the fuel cell stack (10) through a stack manifold. Additionally, the fuel cell unit (100) in the present disclosure has at least a first auxiliary device (30A) as the auxiliary device (30). The locations of the auxiliary device (30) and the first auxiliary device (30A) are as described above. The stack manifold is a piping component that supplies, for example, oxidizer gas, fuel gas, and coolant to the fuel cell stack (10). The shape and material of the stack manifold are not particularly limited and can be appropriately adjusted.

[0041] The type of the first auxiliary device (30A) is not particularly limited, but examples include devices related to water circulation of the fuel cell stack (10), such as a gas-liquid separator, a humidifier, and an ejector. Additionally, the fuel cell unit (100) may have only one first auxiliary device (30A) or may have two or more first auxiliary devices (30A).

[0042] Additionally, the fuel cell unit (100) in the present disclosure may have a second auxiliary device (30B) as an auxiliary device (30). As shown in FIG. 7a and FIG. 7b, the entire area C enclosed by the outer edge of the second auxiliary device (30B) is contained within the inner side of either the aforementioned area B1 or area B2. As shown in FIG. 7a, the entire area C may be contained within the inner side of area B1. On the other hand, as shown in FIG. 7b, the entire area C may be contained within the inner side of area B2.

[0043] In addition, regarding the shape of the second auxiliary device (30B) and the extension direction of the second auxiliary device (30B) when viewed from the above plane, it can be made in the same way as the shape and direction described for the first auxiliary device (30A).

[0044] As for the second auxiliary device (30B), for example, a device for water circulation of the fuel cell stack (10), such as a gas-liquid separator, a humidifier, and an ejector, may be used. Additionally, the fuel cell unit (100) may have only one second auxiliary device (30B) or may have two or more second auxiliary devices (30B).

[0045] In addition, the fuel cell unit (100) in the present disclosure preferably does not have an auxiliary device (30) protruding from area B3 as an auxiliary device (30). This improves the mounting capability of the fuel cell unit (100).

[0046] 4. Fuel cell unit

[0047] For use of the fuel cell unit (100) in the present disclosure, for example, a vehicle such as a fuel cell vehicle (FCEV). In addition, the fuel cell unit (100) in the present disclosure may be used in a moving object other than a vehicle (e.g., a railway, a ship, an aircraft), or may be used in a moving object other than a moving object.

[0048] The present disclosure is not limited to the above embodiments. The above embodiments are examples, and any configuration substantially identical to the technical concept described in the claims of the present disclosure and exhibiting the same functional effects is included within the technical scope of the present disclosure.

Claims

Claim 1 A fuel cell stack (10), a power converter (20) configured to convert the power of the fuel cell stack (10), and an auxiliary device (30) configured to assist in the operation of the fuel cell stack (10), comprising at least a first auxiliary device (30A), wherein the power converter (20) is positioned on a first surface (X) of the fuel cell stack (10), and the auxiliary device (30) is connected to a second surface (Y) of the fuel cell stack (10) through a stack manifold, and the normal direction (M) of the first surface (X) and the normal direction (N) of the second surface (Y) intersect, and when viewing the fuel cell unit (100) as a plane from the side of the auxiliary device (30), the area enclosed by the outer edge of the first auxiliary device (30A) is designated as area A, the area enclosed by the outer edge of the fuel cell stack (10) is designated as area B1, and the area enclosed by the outer edge of the power converter (20) is designated as area B2. And, when the area formed by summing the above area B1 and the above area B2 is defined as area B3, the above area A overlaps with at least a part of the above area B1 and at least a part of the above area B2, and the entirety of the above area A is included within the area B3, and for the entirety of the above area A, the ratio of the part of the above area A that overlaps with the above area B1 is 50% or more, and the fuel cell unit (100) includes a second auxiliary device (30B) as the auxiliary device (30), and when the area enclosed by the outer edge of the second auxiliary device (30B) is defined as area C when viewed from the above plane, the entirety of the above area C is included within the area B1, and the first auxiliary device (30A) and the second auxiliary device (30B) are each connected to the second surface (Y) of the fuel cell stack (10), the fuel cell unit (100). Claim 2 delete Claim 3 In claim 1, the fuel cell unit (100) is a fuel cell unit (100) that does not have an auxiliary device (30) protruding from area B3. Claim 4 In claim 1, the first auxiliary device (30A) is a fuel cell unit (100) which is at least one of a gas-liquid separator, a humidifier, and an ejector. Claim 5 In claim 1, the fuel cell unit (100) has a converter and an inverter as the power converter (20), and the converter and the inverter are arranged in order on the first side (X). Claim 6 delete Claim 7 delete

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