Fuel cell system and method for cold start of fuel cell system

Abstract

The present invention relates to a fuel cell system and a low-temperature startup method for the fuel cell system. In the fuel cell system (10), a first rubber seal (94) is sandwiched between a top portion (92a) of a first sealing protrusion (92) and an MEA component (46). The first sealing protrusion (92) is formed to protrude from a first separator body (78). The low-temperature startup method for the fuel cell system (10) includes: a preheating step in which oxidant gas ejected from a compressor (154) is circulated through a pressure loss component (166) and introduced into a housing inner space (S) in a heated state to preheat the fuel cell stack (12); and a power generation step in which power generation is started after the preheating step.

Description

Technical Field

[0001] The present invention relates to a fuel cell system and a low-temperature starting method of the fuel cell system. Background Art

[0002] A fuel cell system includes a fuel cell stack. The fuel cell stack comprises a plurality of stacked power-generating cells. Each power-generating cell includes an electrochemically activated molecular assemblies (MEA) component and a set of metal separators. The MEA component is disposed between the metal separators. The MEA component generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas. The fuel cell system includes an oxidant gas supply path for supplying oxidant gas to the fuel cell stack. A compressor is provided in the oxidant gas supply path.

[0003] For example, Patent Document 1 discloses that when the temperature of a fuel cell stack is below a predetermined temperature (eg, below 0° C.), relatively high-temperature oxidant gas discharged from a compressor is supplied into the fuel cell stack to preheat the fuel cell stack.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-59922 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, each metal separator has a sealing protrusion that prevents leakage of the oxidant gas, fuel gas, or coolant fluid. The sealing protrusion is integrally formed with the metal separator, protruding from the metal separator toward the MEA component. A rubber seal is sometimes sandwiched between the top of the sealing protrusion and the MEA component. This rubber seal tends to leak fuel gas at low temperatures. Therefore, in such a fuel cell system, there is a possibility that a small amount of fuel gas may leak from the rubber seal when the power generation cell is operating in a low-temperature environment.

[0009] The present invention aims to solve the above-mentioned problems.

[0010] Solutions for solving problems

[0011] 19. The fuel cell system of claim 18, wherein the plurality of power generation cells include an MEA component for generating electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components arranged on both sides of the MEA component; a stack casing for accommodating the fuel cell stack; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged in the oxidant gas supply path, wherein the two separator components each have a metal separator body, a sealing protrusion integrally formed with the separator body, the sealing protrusion being used to prevent leakage of a fluid serving as the oxidant gas, the fuel gas or the cooling medium, the sealing protrusion protruding from the separator body in the stacking direction of the plurality of power generation cells, a rubber seal being sandwiched between the top of the sealing protrusion and the MEA component, and a compressor arranged in the oxidant gas supply path. 19. The fuel cell system of claim 18, wherein the fuel cell system comprises: a preheating inlet passage for introducing the oxidant gas ejected from the compressor to the oxidant gas supply passage into the space inside the shell between the stack shell and the fuel cell stack; and a switching unit capable of switching between a first state and a second state, the first state being a state in which the oxidant gas is allowed to be supplied from the oxidant gas supply passage to the fuel cell stack and the introduction of the oxidant gas from the oxidant gas supply passage to the space inside the shell via the preheating inlet passage is blocked, the second state being a state in which the oxidant gas is blocked from being supplied from the oxidant gas supply passage to the fuel cell stack and the introduction of the oxidant gas from the oxidant gas supply passage to the space inside the shell via the preheating inlet passage, wherein a pressure loss component is installed in the preheating inlet passage, and the pressure loss component is used to increase the pressure loss of the oxidant gas flowing through the preheating inlet passage.

[0012] 19. The fuel cell system of claim 18, wherein the fuel cell stack comprises a plurality of stacked power generation cells, a first end plate disposed at one end of the stacked power generation cells, and a second end plate disposed at the other end of the stacked power generation cells, wherein the plurality of power generation cells include an MEA component for generating electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components disposed on both sides of the MEA component; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor disposed in the oxidant gas supply path, wherein the two separator components each have a metal separator body, a sealing protrusion integrally formed with the separator body, the sealing protrusion being used to prevent leakage of a fluid serving as the oxidant gas, the fuel gas or the cooling medium, the sealing protrusion protruding from the separator body in the stacking direction of the plurality of power generation cells, and a rubber seal. The component is sandwiched between the top of the sealing protrusion and the MEA component, and each of the multiple power generation cells has an oxidant gas supply connecting hole for supplying the oxidant gas to the power generation area of the multiple power generation cells. In the fuel cell system, the first end panel has an oxidant gas inlet for introducing the oxidant gas from the oxidant gas supply path to the oxidant gas supply connecting hole, and the second end panel has a preheating oxidant gas outlet for exporting the oxidant gas from the oxidant gas supply connecting hole to the outside of the fuel cell stack. The fuel cell stack has an export valve that can be switched between a first state and a second state, the first state is a state allowing the oxidant gas to be exported from the preheating oxidant gas outlet to the outside of the fuel cell stack, and the second state is a state blocking the export of the oxidant gas from the preheating oxidant gas outlet to the outside of the fuel cell stack.

[0013] A third embodiment of the present invention relates to a low-temperature startup method for a fuel cell system, wherein the fuel cell system comprises: a fuel cell stack having a single-cell stack formed by stacking a plurality of power-generating cells, the plurality of power-generating cells including an MEA component for generating electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components arranged on both sides of the MEA component; a stack housing for accommodating the fuel cell stack; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged in the oxidant gas supply path, the two separator components each having a metal separator body, a sealing protrusion integrally formed with the separator body, and the sealing protrusion for preventing the oxidant gas from , the fluid of the fuel gas or cooling medium leaks, the sealing protrusion protrudes from the partition body in the stacking direction of the multiple power generation cells, and the rubber seal is sandwiched between the top of the sealing protrusion and the MEA component. In the low-temperature start-up method of the fuel cell system, it includes: a preheating process, in which the oxidant gas ejected from the compressor is circulated in the pressure loss component and introduced into the shell space between the stack shell and the fuel cell stack in a heated state to preheat the fuel cell stack; and a power generation process, after the preheating process, the oxidant gas ejected from the compressor is supplied to the power generation cell and the fuel gas is supplied to the power generation cell to start power generation.

[0014] A fourth embodiment of the present invention relates to a low-temperature start-up method for a fuel cell system, the fuel cell system comprising: a fuel cell stack having a single cell stack formed by stacking a plurality of power generation cells, a first end plate arranged at one end of the single cell stack, and a second end plate arranged at the other end of the single cell stack, the plurality of power generation cells including an MEA component that generates electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components arranged on both sides of the MEA component; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged at the oxygen The two separator members each have a metal separator body, and the sealing protrusion is integrally formed with the separator body. The sealing protrusion is used to prevent leakage of the fluid serving as the oxidant gas, the fuel gas or the cooling medium. The sealing protrusion protrudes from the separator body in the stacking direction of the multiple power generation cells. The rubber seal is sandwiched between the top of the sealing protrusion and the MEA member. The multiple power generation cells each have an oxidant gas supply connecting hole for supplying the oxidant gas to the power generation area of the multiple power generation cells. In the startup method, the first end panel has an oxidant gas inlet for introducing the oxidant gas from the oxidant gas supply path to the oxidant gas supply connecting hole, and the second end panel has a preheating oxidant gas outlet for discharging the oxidant gas from the oxidant gas supply connecting hole to the outside of the fuel cell stack. The fuel cell stack has an outlet valve that can be switched between a first state and a second state, the first state is a state that allows the oxidant gas to be discharged from the preheating oxidant gas outlet to the outside of the fuel cell stack, and the second state is a state that blocks the oxidant gas from being discharged from the preheating oxidant gas outlet to the outside of the fuel cell stack. The low-temperature startup method of the fuel cell system includes: a preheating process, in which the outlet valve is set to the first state, and the oxidant gas ejected from the compressor is caused to flow through the oxidant gas supply connecting hole, thereby preheating the fuel cell stack; and a power generation process, in which, after the preheating process, the outlet valve is set to the second state, the oxidant gas ejected from the compressor is supplied to the power generation area of the multiple power generation cells, and the fuel gas is supplied to the power generation area of the multiple power generation cells, thereby starting power generation.

[0015] Effects of the Invention

[0016] According to the first aspect of the present invention, when the power generation cell is generating electricity in a low-temperature environment, the switching unit is set to the second state and the compressor is driven. This allows the relatively high-temperature oxidant gas ejected from the compressor to be introduced into the space within the housing while being heated by the pressure loss component. This effectively heats the rubber seal of the fuel cell stack. Furthermore, when the rubber seal is sufficiently heated, the switching unit is set to the first state, allowing the oxidant gas ejected from the compressor to be supplied to the fuel cell stack, thereby enabling the power generation of the power generation cell to commence. Thus, the rubber seal can be efficiently heated using a simple structure. This effectively prevents fuel gas leakage from the rubber seal when the power generation cell is generating electricity in a low-temperature environment.

[0017] According to the second embodiment of the present invention, when generating electricity from a power generation cell in a low-temperature environment, the outlet valve can be placed in the first position and the compressor can be driven, thereby allowing the relatively high-temperature oxidant gas ejected from the compressor to flow through the oxidant gas supply passage. This allows the fuel cell stack's rubber seal to be efficiently heated. Furthermore, after the rubber seal has been sufficiently heated, the outlet valve is placed in the second position, allowing the oxidant gas ejected from the compressor to be supplied to the power generation area of each power generation cell. Thus, power generation from the power generation cell can be initiated. Thus, the rubber seal can be efficiently heated using a simple structure. This effectively prevents fuel gas leakage from the rubber seal when generating electricity from the power generation cell in a low-temperature environment.

[0018] According to the third aspect of the present invention, a preheating process is performed, whereby the relatively high-temperature oxidant gas ejected from the compressor is circulated through the pressure loss component and introduced into the space within the housing in a heated state to preheat the fuel cell stack. This allows the fuel cell stack's rubber seals to be efficiently heated in a low-temperature environment. Furthermore, after the preheating process, a power generation process is performed, whereby the oxidant gas ejected from the compressor is supplied to the power generation cells, and fuel gas is supplied to the power generation cells, thereby initiating power generation. Thus, the rubber seals can be efficiently heated using a simple structure. This effectively prevents fuel gas from leaking from the rubber seals when the power generation cells generate electricity in a low-temperature environment.

[0019] According to the fourth aspect of the present invention, a preheating step is performed, in which the outlet valve is set to the first position, allowing the relatively high-temperature oxidant gas discharged from the compressor to flow through the oxidant gas supply passage, thereby preheating the fuel cell stack. This allows the fuel cell stack's rubber seal to be efficiently heated in a low-temperature environment. Furthermore, a power generation step is performed, and after the preheating step, the outlet valve is set to the second position, supplying the oxidant gas discharged from the compressor to the power generation area of the power generation cell, and fuel gas to the power generation area of the power generation cell, thereby initiating power generation. This allows the rubber seal to be efficiently heated using a simple structure, effectively suppressing fuel gas leakage from the rubber seal during power generation in a low-temperature environment.

[0020] The above-mentioned objects, features, and advantages will be easily understood by referring to the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic configuration diagram of a fuel cell system according to a first embodiment of the present invention.

[0022] Figure 2 yes Figure 1 A cross-sectional illustration of a fuel cell stack and a stack casing.

[0023] Figure 3 It is along Figure 2 A cross-sectional illustration of line III-III in FIG.

[0024] Figure 4 yes Figure 2 A three-dimensional diagram of a fuel cell stack.

[0025] Figure 5 yes Figure 4 A partially exploded perspective view of a single cell stack.

[0026] Figure 6 It is along Figure 5 A partially omitted cross-sectional view of the VI-VI line.

[0027] Figure 7 This is a plan view of the bonded separators as viewed from the first separator member toward the second separator member.

[0028] Figure 8 This is a plan view of the bonded separators as viewed from the second separator member toward the first separator member.

[0029] Figure 9 Graph showing the relationship between the temperature of the rubber seal and the amount of fuel gas leakage.

[0030] Figure 10A It is an explanation Figure 1Flowchart of a low-temperature startup method for a fuel cell system.

[0031] Figure 10B It is an explanation Figure 10A Flowchart of the preheating process.

[0032] Figure 11 This is a diagram illustrating the preheating process.

[0033] Figure 12 This diagram illustrates the power generation process.

[0034] Figure 13 It is a cross-sectional explanatory diagram of a stack casing according to a modified example.

[0035] Figure 14 It is along Figure 13 A cross-sectional illustration of the line XIV-XIV in FIG.

[0036] Figure 15 This is a schematic configuration diagram of a fuel cell system according to a second embodiment of the present invention.

[0037] Figure 16 yes Figure 15 A cross-sectional illustration of a fuel cell stack and a stack casing.

[0038] Figure 17 It is an explanation Figure 15 Flowchart of the preheating process of the low-temperature startup method of the fuel cell system.

[0039] Figure 18 This is a schematic configuration diagram of a fuel cell system according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0040] (First embodiment)

[0041] The first embodiment of the present invention relates to Figure 1 The fuel cell system 10 shown is mounted on a fuel cell vehicle (not shown) such as a fuel cell electric vehicle, etc. Furthermore, the fuel cell system 10 may be a stationary type.

[0042] like Figure 1 As shown, the fuel cell system 10 includes a fuel cell stack 12 , a stack case 14 , an anode system device 16 , a cathode system device 18 , and a cooling device 20 .

[0043] exist Figures 2 to 4In the figure, the fuel cell stack 12 includes a cell stack 24 formed by stacking a plurality of power generation cells 22 in the direction indicated by arrow A. Each power generation cell 22 generates electricity through an electrochemical reaction between an oxidant gas (e.g., oxygen-containing gas) and a fuel gas (e.g., hydrogen-containing gas). In the following description, the stacking direction of the plurality of power generation cells 22 may be simply referred to as the "stacking direction."

[0044] At one end of the stacking direction of the cell stack 24 (the end in the direction of arrow A1), a first wiring member 26a, a first insulating plate 28a, and a first end plate 30a are disposed in this order, facing outward (in the direction of arrow A1). At the other end of the stacking direction of the cell stack 24 (the end in the direction of arrow A2), a second wiring member 26b, a second insulating plate 28b, and a second end plate 30b are disposed in this order, facing outward (in the direction of arrow A2). Fuel cell stack 12 includes first wiring member 26a, first insulating plate 28a, first end plate 30a, second wiring member 26b, second insulating plate 28b, and second end plate 30b.

[0045] First wiring member 26a and second wiring member 26b collect (collect) the electricity generated by each power generating cell 22. First wiring member 26a and second wiring member 26b are formed in a plate shape (a square plate shape). First wiring member 26a and second wiring member 26b are conductive.

[0046] exist Figure 2 as well as Figure 3 In the embodiment, first wiring member 26a is disposed in first recess 32a formed on the inner surface (the surface in the direction of arrow A2) of first insulating plate 28a. First wiring member 26a is electrically connected to first terminal portion 34a protruding from first end plate 30a (see FIG. Figure 4 ).

[0047] Second wiring member 26b is disposed in second recess 32b formed on the inner surface of second insulating plate 28b (the surface in the direction of arrow A1). Second wiring member 26b is electrically connected to second terminal portion 34b protruding from second end plate 30b (see FIG. 1 ). Figure 4 The first insulating plate 28a and the second insulating plate 28b have electrical insulation properties.

[0048] exist Figure 4 In the embodiment, the first end panel 30a and the second end panel 30b have a horizontally long rectangular shape. A connecting rod 36 is arranged between each side of the first end panel 30a and the second end panel 30b. Figure 2 as well as Figure 3 In the figure, the connecting rod 36 is omitted for convenience.

[0049] One end of the connecting rod 36 (the end in the direction of arrow A1) is fastened to the inner surface of the first end panel 30a by a bolt 38. The other end of the connecting rod 36 (the end in the direction of arrow A2) is fastened to the inner surface of the second end panel 30b by a bolt (not shown). The connecting rod 36 applies a compressive load in the stacking direction to the cell stack 24.

[0050] like Figure 4 As shown, the first end panel 30a and the first insulating plate 28a have an oxidant gas inlet 40a, a coolant inlet 42a, and a fuel gas outlet 44b at one end of their longitudinal sides. The longitudinal ends of the first end panel 30a and the first insulating plate 28a are those of the first end panel 30a and the first insulating plate 28a in the direction of arrow B1. The oxidant gas inlet 40a, the coolant inlet 42a, and the fuel gas outlet 44b are arranged in a row along the lateral direction of the first end panel 30a. The lateral direction of the first end panel 30a is along the direction of arrow C.

[0051] The oxidant gas inlet 40a is used to introduce oxidant gas into the fuel cell stack 12. The cooling medium inlet 42a is used to introduce a cooling medium (e.g., pure water, ethylene glycol, oil, etc.) into the fuel cell stack 12. The fuel gas outlet 44b is used to discharge the fuel gas consumed by power generation, i.e., the fuel exhaust (including unreacted fuel gas), from the fuel cell stack 12.

[0052] The other longitudinal edge of the first end panel 30a and the first insulating plate 28a includes a fuel gas inlet 44a, a coolant outlet 42b, and an oxidant gas outlet 40b. The other longitudinal edge of the first end panel 30a and the first insulating plate 28a is the edge of the first end panel 30a and the first insulating plate 28a in the direction of arrow B2. The fuel gas inlet 44a, the coolant outlet 42b, and the oxidant gas outlet 40b are arranged in the direction of arrow C.

[0053] The fuel gas inlet 44a is used to introduce fuel gas into the fuel cell stack 12. The coolant outlet 42b is used to discharge the coolant from the fuel cell stack 12. The oxidant gas outlet 40b is used to discharge the oxidant gas consumed by power generation, that is, the oxidant exhaust (including unreacted oxidant gas), from the fuel cell stack 12.

[0054] like Figure 5As shown, each power generating cell 22 has a horizontally long rectangular shape. Each power generating cell 22 includes an MEA member 46 (MEA with a resin frame), a first separator member 48, and a second separator member 50. The MEA member 46 is disposed between the first separator member 48 and the second separator member 50. The first separator member 48 and the second separator member 50 are joined to each other by a plurality of bonding wires (not shown) to form a bonded separator 52.

[0055] MEA component 46 generates electricity through an electrochemical reaction between oxidant gas and fuel gas. MEA component 46 includes MEA 54 (electrolyte membrane-electrode assembly) and a resin frame component 56. Resin frame component 56 protrudes outward from the outer periphery of MEA 54. Resin frame component 56 is attached to the outer periphery of MEA component 46.

[0056] exist Figure 6 In the embodiment, MEA 54 includes an electrolyte membrane 58, a first electrode 60, and a second electrode 62. The first electrode 60 is disposed on one surface 58a of the electrolyte membrane 58. The second electrode 62 is disposed on the other surface 58b of the electrolyte membrane 58. The electrolyte membrane 58 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). The solid polymer electrolyte membrane is, for example, a thin film of perfluorosulfonic acid containing water. The electrolyte membrane 58 is sandwiched between the first electrode 60 and the second electrode 62. The electrolyte membrane 58 may also be a fluorine-based electrolyte or an HC (hydrocarbon)-based electrolyte.

[0057] The first electrode 60 includes a first electrode catalyst layer 64 and a first gas diffusion layer 66. The first electrode catalyst layer 64 is bonded to one surface 58a of the electrolyte membrane 58. The first gas diffusion layer 66 is laminated on the first electrode catalyst layer 64. The second electrode 62 includes a second electrode catalyst layer 68 and a second gas diffusion layer 70. The second electrode catalyst layer 68 is bonded to the other surface 58b of the electrolyte membrane 58. The second gas diffusion layer 70 is laminated on the second electrode catalyst layer 68.

[0058] The first electrode catalyst layer 64, for example, comprises porous carbon particles with a platinum alloy supported on their surfaces. These porous carbon particles are uniformly applied to the surface of the first gas diffusion layer 66 together with an ion-conductive polymer binder. The second electrode catalyst layer 68, for example, comprises porous carbon particles with a platinum alloy supported on their surfaces. These porous carbon particles are uniformly applied to the surface of the second gas diffusion layer 70 together with an ion-conductive polymer binder. The first gas diffusion layer 66 and the second gas diffusion layer 70 are made of carbon paper, carbon cloth, or the like.

[0059] The resin frame member 56 has electrical insulation properties. Examples of materials for the resin frame member 56 include PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), silicone resin, fluororesin, m-PPE (modified polyphenylene ether resin), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), and modified polyolefins.

[0060] The resin frame member 56 is formed into a quadrilateral ring shape (see Figure 5 The inner peripheral portion 56i of the resin frame member 56 is disposed between the outer peripheral portion 60o of the first electrode 60 and the outer peripheral portion 62o of the second electrode 62. Specifically, the inner peripheral portion 56i of the resin frame member 56 is sandwiched between the outer peripheral portion 58o of the electrolyte membrane 58 and the outer peripheral portion 62o of the second electrode 62. Alternatively, the inner peripheral portion 56i of the resin frame member 56 may be sandwiched between the outer peripheral portion 58o of the electrolyte membrane 58 and the outer peripheral portion 60o of the first electrode 60.

[0061] like Figure 5 As shown, each power generation cell 22 has an oxidant gas supply manifold 72a, a coolant supply manifold 74a, and a fuel gas exhaust manifold 76b at one end of its longitudinal direction. This end of each power generation cell 22 corresponds to the end of each power generation cell 22 in the direction of arrow B1. The oxidant gas supply manifold 72a, the coolant supply manifold 74a, and the fuel gas exhaust manifold 76b are arranged in a row along the transverse direction of each power generation cell 22. The transverse direction of each power generation cell 22 is along the direction of arrow C.

[0062] exist Figure 4 as well as Figure 5 In the embodiment, the oxidant gas introduced from the oxidant gas inlet 40a flows through the oxidant gas supply passage 72a in the direction of arrow A2. The oxidant gas flowing through the oxidant gas supply passage 72a is supplied to the power generation region 23 of each power generation cell 22. The coolant introduced from the coolant inlet 42a flows through the coolant supply passage 74a in the direction of arrow A2. The exhaust fuel gas flows through the fuel gas discharge passage 76b in the direction of arrow A1. The exhaust fuel gas flowing through the fuel gas discharge passage 76b is discharged from the fuel gas outlet 44b.

[0063] like Figure 5As shown, the other longitudinal edge of each power generation cell 22 includes a fuel gas supply manifold 76a, a coolant discharge manifold 74b, and an oxidant gas discharge manifold 72b. The other longitudinal edge of each power generation cell 22 corresponds to the edge of each power generation cell 22 in the direction of arrow B2. The fuel gas supply manifold 76a, the coolant discharge manifold 74b, and the oxidant gas discharge manifold 72b are arranged in the direction of arrow C.

[0064] exist Figure 4 as well as Figure 5 In FIG. 4 , the fuel gas introduced from the fuel gas inlet 44a flows through the fuel gas supply manifold 76a in the direction of arrow A2. The fuel gas flowing through the fuel gas supply manifold 76a is supplied to the power generation region 23 of each power generation cell 22. The coolant flows through the coolant discharge manifold 74b in the direction of arrow A1. The coolant flowing through the coolant discharge manifold 74b is discharged from the coolant outlet 42b. The oxidant exhaust flows through the oxidant gas discharge manifold 72b in the direction of arrow A1. The oxidant exhaust flowing through the oxidant gas discharge manifold 72b is discharged from the oxidant gas outlet 40b.

[0065] The number, arrangement, shape, and size of the aforementioned communication holes (such as the oxidant gas supply communication hole 72a) are not limited to those of the present embodiment and may be appropriately set according to the required specifications. The same applies to the aforementioned oxidant gas inlet 40a, oxidant gas outlet 40b, fuel gas inlet 44a, fuel gas outlet 44b, coolant inlet 42a, and coolant outlet 42b.

[0066] like Figure 7 As shown, the first partition member 48 includes a rectangular first partition body 78. The first partition body 78 is formed by stamping a thin metal plate into a corrugated cross-section. The thin metal plate may be, for example, a steel plate, a stainless steel plate, an aluminum plate, or a plated steel plate. Alternatively, the thin metal plate may be a stainless steel plate or an aluminum plate with a surface treatment for corrosion resistance.

[0067] The surface of the first separator body 78 facing the MEA component 46 (hereinafter referred to as "surface 78a") includes an oxidant gas flow path 80 (reactant gas flow path) extending along the longitudinal direction (direction of arrow B) of each power generation cell 22. The oxidant gas flow path 80 is fluidically connected to the oxidant gas supply passage 72a and the oxidant gas discharge passage 72b. The oxidant gas flow path 80 supplies oxidant gas to the first electrode 60.

[0068] The oxidant gas flow path 80 has a plurality of first flow path grooves 84. Each first flow path groove 84 is located between a plurality of first flow path protrusions 82 extending in the direction of arrow symbol B. That is, in the oxidant gas flow path 80, the first flow path protrusions 82 and the first flow path grooves 84 are alternately arranged in the flow path width direction (the direction of arrow symbol C). The plurality of first flow path protrusions 82 and the plurality of first flow path grooves 84 are integrally formed with the first separator body 78 by stamping. The first flow path protrusions 82 and the first flow path grooves 84 extend linearly in the direction of arrow symbol B. However, the first flow path protrusions 82 and the first flow path grooves 84 may also extend in a wavy manner in the direction of arrow symbol B.

[0069] A first sealing portion 86 is provided on the surface 78a of the first separator body 78. This first sealing portion 86 prevents leakage of a fluid serving as a reactant gas (oxidant gas or fuel gas) or a coolant. When viewed in the separator thickness direction (direction indicated by arrow A), the first sealing portion 86 extends linearly. However, when viewed in the separator thickness direction (the stacking direction), the first sealing portion 86 may extend in a wavy pattern.

[0070] The first sealing portion 86 includes a plurality of first communication hole sealing portions 88 and a first flow path sealing portion 90. The plurality of first communication hole sealing portions 88 individually surround the plurality of communication holes (such as the oxidizing gas supply communication hole 72a). The first flow path sealing portion 90 is located on the outer periphery of the first separator body 78.

[0071] Hereinafter, the sealing portion of the plurality of first communication hole sealing portions 88 surrounding the oxidant gas supply communication hole 72a will be referred to as the "first communication hole sealing portion 88a," and the sealing portion surrounding the oxidant gas discharge communication hole 72b will be referred to as the "first communication hole sealing portion 88b." Furthermore, the sealing portion of the plurality of first communication hole sealing portions 88 surrounding the fuel gas supply communication hole 76a will be referred to as the "first communication hole sealing portion 88c," and the sealing portion surrounding the fuel gas discharge communication hole 76b will be referred to as the "first communication hole sealing portion 88d." Furthermore, the sealing portion of the plurality of first communication hole sealing portions 88 surrounding the coolant supply communication hole 74a will be referred to as the "first communication hole sealing portion 88e," and the sealing portion surrounding the coolant discharge communication hole 74b will be referred to as the "first communication hole sealing portion 88f."

[0072] The first flow path sealing portion 90 prevents leakage of the reaction gas (oxidant gas). The first flow path sealing portion 90 surrounds the oxidant gas flow path 80 and the plurality of first communication hole sealing portions 88a to 88d. The first communication hole sealing portions 88e and 88f are located outside the first flow path sealing portion 90.

[0073] like Figure 6As shown, the first sealing portion 86 includes a first sealing protrusion 92 and a first rubber seal 94 (microseal). The first sealing protrusion 92 is integrally formed with the first separator body 78 by stamping so as to protrude toward the MEA component 46. The first rubber seal 94 is mounted on the top 92a of the first sealing protrusion 92. The cross-sectional shape of the first sealing protrusion 92 is trapezoidal. In other words, the cross-sectional shape of the first sealing protrusion 92 is tapered toward the protruding direction of the first sealing protrusion 92. In other words, the first sealing protrusion 92 is elastically deformed by the compressive load in the direction of the arrow symbol A. Alternatively, the cross-sectional shape of the first sealing protrusion 92 may be rectangular or square.

[0074] The first rubber seal 94 is an elastic member fixed to the top 92a (protruding end surface) of the first sealing protrusion 92. The first rubber seal 94 is made of, for example, fluororubber foam (fluororubber foam). Fluororubber foam is suitable as a structural material for the first rubber seal 94 due to its excellent sealing properties (gas permeability), heat resistance, and chemical resistance.

[0075] Alternatively, the first rubber seal 94 can be formed by affixing a fluororubber foam seal to the top 92a of the first sealing protrusion 92. In this case, there is no need to apply the rubber material to the top 92a of the first sealing protrusion 92 using a dispenser or coater, thereby reducing manufacturing costs.

[0076] The structural material of the first rubber seal 94 is not limited to the above-mentioned materials, and may also be EPDM (ethylene-propylene rubber), NBR (nitrile rubber), silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber, as well as porous bodies (foams) of the above-mentioned rubbers.

[0077] The thickness of the first rubber seal 94 is, for example, not less than 30 μm and not more than 200 μm. However, the thickness of the first rubber seal 94 can be set as appropriate. The first rubber seal 94 is sandwiched between the top 92 a of the first sealing protrusion 92 and the resin frame member 56 . Alternatively, the first rubber seal 94 may be fixed to the resin frame member 56 rather than to the first sealing protrusion 92 .

[0078] like Figure 8 As shown, the second partition member 50 includes a rectangular second partition body 96. The second partition body 96 is formed by stamping a thin metal plate into a corrugated cross-section. The thin metal plate may be, for example, a steel plate, a stainless steel plate, an aluminum plate, or a plated steel plate. Alternatively, the thin metal plate may be a stainless steel plate with a surface treatment for corrosion resistance or an aluminum plate with a surface treatment for corrosion resistance.

[0079] The surface of the second separator body 96 facing the MEA component 46 (hereinafter referred to as "surface 96a") includes a fuel gas flow path 98 (reactant gas flow path) extending along the longitudinal direction (direction of arrow B) of each power generating cell 22. The fuel gas flow path 98 is fluidically connected to the fuel gas supply passage 76a and the fuel gas discharge passage 76b. The fuel gas flow path 98 supplies fuel gas to the second electrode 62.

[0080] The fuel gas flow path 98 has a plurality of second flow path grooves 102. Each second flow path groove 102 is located between a plurality of second flow path protrusions 100 extending in the direction of arrow symbol B. That is, in the fuel gas flow path 98, the second flow path protrusions 100 and the second flow path grooves 102 are alternately arranged in the flow path width direction (the direction of arrow symbol C). The plurality of second flow path protrusions 100 and the plurality of second flow path grooves 102 are integrally formed with the second separator body 96 by stamping. The second flow path protrusions 100 and the second flow path grooves 102 extend linearly in the direction of arrow symbol B. However, the second flow path protrusions 100 and the second flow path grooves 102 may also extend in a wavy manner in the direction of arrow symbol B.

[0081] A second sealing portion 104 is provided on the surface 96a of the second partition body 96. The second sealing portion 104 is used to prevent leakage of a fluid serving as a reaction gas (oxidant gas or fuel gas) or a cooling medium. When viewed from the partition thickness direction (direction of arrow symbol A), the second sealing portion 104 extends in a straight line. However, it is also possible that the second sealing portion 104 extends in a wavy shape when viewed from the partition thickness direction (stack direction). When viewed from the partition thickness direction (stack direction), the second sealing portion 104 overlaps with the first sealing portion 86 (refer to FIG. Figure 6 ).

[0082] The second sealing portion 104 includes a plurality of second communication hole sealing portions 106 and a second flow path sealing portion 108. The plurality of second communication hole sealing portions 106 individually surround the plurality of communication holes (such as the oxidizing gas supply communication hole 72a). The second flow path sealing portion 108 is located on the outer periphery of the first separator body 78.

[0083] Hereinafter, the sealing portion of the plurality of second communication hole sealing portions 106 that surrounds the oxidant gas supply communication hole 72a will be referred to as the "second communication hole sealing portion 106a," and the sealing portion that surrounds the oxidant gas discharge communication hole 72b will be referred to as the "second communication hole sealing portion 106b." Furthermore, the sealing portion of the plurality of second communication hole sealing portions 106 that surrounds the fuel gas supply communication hole 76a will be referred to as the "second communication hole sealing portion 106c," and the sealing portion that surrounds the fuel gas discharge communication hole 76b will be referred to as the "second communication hole sealing portion 106d." Furthermore, the sealing portion of the plurality of second communication hole sealing portions 106 that surrounds the coolant supply communication hole 74a will be referred to as the "second communication hole sealing portion 106e," and the sealing portion that surrounds the coolant discharge communication hole 74b will be referred to as the "second communication hole sealing portion 106f."

[0084] Second flow path sealing portion 108 prevents leakage of reaction gas (fuel gas). Second flow path sealing portion 108 surrounds fuel gas flow path 98 and multiple second communication hole sealing portions 106a to 106d. Second communication hole sealing portions 106e and 106f are located outside second flow path sealing portion 108.

[0085] like Figure 6 As shown, the second sealing portion 104 includes a second sealing protrusion 110 and a second rubber seal 112 (microseal). The second sealing protrusion 110 is integrally formed with the second separator body 96 by stamping so as to protrude toward the MEA component 46. The second rubber seal 112 is attached to the top 110a of the second sealing protrusion 110. The cross-sectional shape of the second sealing protrusion 110 is trapezoidal. In other words, the cross-sectional shape of the second sealing protrusion 110 is tapered toward the protruding direction of the second sealing protrusion 110. In other words, the second sealing protrusion 110 is elastically deformed by the compressive load in the direction of arrow A. Alternatively, the cross-sectional shape of the second sealing protrusion 110 may be rectangular or square.

[0086] The second rubber seal 112 is an elastic member fixed to the top 110a (protruding end surface) of the second sealing protrusion 110. The second rubber seal 112 is made of the same structural material as the first rubber seal 94 described above.

[0087] The second rubber seal 112 is sandwiched between the top portion 110a of the second sealing protrusion 110 and the resin frame member 56. Alternatively, the second rubber seal 112 may be fixed to the resin frame member 56 instead of the second sealing protrusion 110.

[0088] like Figure 5As shown, coolant flow path 114 is located between surface 78b of first separator body 78 and surface 96b of second separator body 96. Coolant flow path 114 is fluidically connected to coolant supply passage 74a and coolant discharge passage 74b. Coolant flow path 114 is formed by overlapping the back surface shapes of first separator body 78 and second separator body 96.

[0089] like Figure 2 as well as Figure 3 As shown, the stack casing 14 accommodates the fuel cell stack 12. The stack casing 14 has a lower wall portion 122, an upper wall portion 124, and a pair of side walls 126. The lower wall portion 122 covers the fuel cell stack 12 from below (in the direction of arrow symbol C1). The upper wall portion 124 covers the fuel cell stack 12 from above (in the direction of arrow symbol C2). The pair of side walls 126 covers the fuel cell stack 12 from the sides (in the direction of arrow symbol B). In addition, the stack casing 14 has a first end wall portion 128 and a second end wall portion 130. The first end wall portion 128 covers the fuel cell stack 12 from the direction of arrow symbol A1. The second end wall portion 130 covers the fuel cell stack 12 from the direction of arrow symbol A2.

[0090] The first mounting member 132 fixed to the first end panel 30a is fixed by bolts (not shown) or the like to a portion of the lower wall 122 between the center in the direction of arrow A and the first end wall 128. The second mounting member 134 fixed to the second end panel 30b is fixed by bolts (not shown) or the like to a portion of the lower wall 122 between the center in the direction of arrow A and the second end wall 130.

[0091] The inlet interface 136 is located at the lower portion of the first end wall 128 and is used to introduce the preheating oxidant gas into the inner space S between the stack casing 14 and the fuel cell stack 12 (see FIG. Figure 2 The introduction interface portion 136 is located approximately in the center of the stack housing 14 (first end wall portion 128) in the width direction (direction of arrow B) (see Figure 3 ).

[0092] The outlet port 138 is located at the upper portion of the second end wall 130 and is used to guide the gas (oxidant gas for heating) in the housing inner space S to the outside of the stack housing 14 (see FIG. Figure 2 The outlet port 138 is located approximately in the center of the stack housing 14 (second end wall 130) in the width direction (direction of arrow B) (see Figure 3 The outlet interface portion 138 is located above the inlet interface portion 136 (in the direction of arrow symbol C2).

[0093] like Figure 1As shown, the anode system device 16 includes a fuel gas tank 140, a fuel gas supply path 142, and a fuel gas exhaust path 144. The fuel gas tank 140 stores high-pressure fuel gas (e.g., high-pressure hydrogen). The fuel gas supply path 142 supplies the fuel gas in the fuel gas tank 140 to the fuel gas inlet 44a of the fuel cell stack 12. The fuel exhaust gas guided from the fuel gas outlet 44b of the fuel cell stack 12 is guided to the fuel gas exhaust path 144. Although not shown in detail, the anode system device 16 includes anode system auxiliary equipment. The anode system auxiliary equipment includes an injector, a valve, a gas-liquid separator, and the like.

[0094] The cathode system 18 includes an oxidant gas supply path 146, an oxidant gas exhaust path 148, a bypass flow path 150, and a preheating inlet path 152. The oxidant gas supply path 146 supplies oxidant gas (air) to the oxidant gas inlet 40a of the fuel cell stack 12. The oxidant exhaust gas discharged from the oxidant gas outlet 40b of the fuel cell stack 12 is directed to the oxidant gas exhaust path 148. The bypass flow path 150 connects the oxidant gas supply path 146 and the oxidant gas exhaust path 148. The preheating inlet path 152 supplies the oxidant gas directed from the oxidant gas supply path 146 to the bypass flow path 150 to the inlet interface portion 136.

[0095] A compressor 154, an intercooler 156, and a switching valve 158 (switching unit) are installed in the oxidant gas supply path 146. The compressor 154 compresses the oxidant gas (air) introduced from an air filter (not shown). The temperature of the oxidant gas discharged from the compressor 154 is higher than the temperature of the oxidant gas sucked into the compressor 154.

[0096] Intercooler 156 cools the oxidant gas discharged from compressor 154 during power generation. Intercooler 156 is water-cooled. In this case, the cooling medium guided from cooling device 20 flows through intercooler 156. Specifically, heat exchange occurs between the oxidant gas discharged from compressor 154 and the cooling medium flowing through intercooler 156, thereby cooling the oxidant gas.

[0097] A switching valve 158 is provided at the connection between the oxidizing gas supply line 146 and the bypass flow path 150. The switching valve 158 is a three-way valve 160. The switching valve 158 connects the upstream flow path 146a, the downstream flow path 146b, and the bypass flow path 150. The upstream flow path 146a is the portion of the oxidizing gas supply line 146 upstream of the connection with the bypass flow path 150. The downstream flow path 146b is the portion of the oxidizing gas supply line 146 downstream of the connection with the bypass flow path 150.

[0098] The switching valve 158 is configured to be switchable between a first state and a second state. In the first state, the switching valve 158 connects the upstream flow path 146a and the downstream flow path 146b to each other, blocks the bypass flow path 150 from connecting to the upstream flow path 146a, and blocks the bypass flow path 150 from connecting to the downstream flow path 146b. In the second state, the switching valve 158 connects the upstream flow path 146a and the bypass flow path 150 to each other, blocks the downstream flow path 146b from connecting to the upstream flow path 146a, and blocks the downstream flow path 146b from connecting to the bypass flow path 150.

[0099] In other words, in the first state, the switching valve 158 allows the supply of oxidant gas from the oxidant gas supply path 146 into the fuel cell stack 12, and blocks the introduction of oxidant gas from the oxidant gas supply path 146 into the housing inner space S via the preheating inlet path 152. In the second state, the switching valve 158 blocks the supply of oxidant gas from the oxidant gas supply path 146 into the fuel cell stack 12, and allows the introduction of oxidant gas from the oxidant gas supply path 146 into the housing inner space S via the preheating inlet path 152.

[0100] A back pressure valve 162 is installed in the oxidant gas discharge passage 148. By adjusting the opening of the back pressure valve 162, the pressure in the oxidant gas flow passage 80 of the fuel cell stack 12 can be adjusted. Furthermore, when the back pressure valve 162 is closed, it blocks the oxidant gas discharge passage 148.

[0101] A bypass valve 164 is provided in the bypass flow path 150. The bypass valve 164 is switchable between an open state in which the bypass flow path 150 is opened and a closed state in which the bypass flow path 150 is closed.

[0102] The preheating introduction path 152 is a flow path for introducing the oxidant gas (heated gas) discharged from the compressor 154 into the casing internal space S. The preheating introduction path 152 is connected between the bypass valve 164 and the switching valve 158 in the bypass flow path 150 .

[0103] A pressure-reducing component 166 is attached to the preheating inlet passage 152. Pressure-reducing component 166 increases the temperature of the oxidant gas by reducing the pressure of the oxidant gas. Pressure-reducing component 166 includes, for example, a throttle portion 168 having a smaller cross-sectional area than that of the oxidant gas supply passage 146. Throttle portion 168 may be a throttle valve or an orifice.

[0104] However, pressure loss member 166 can have an appropriate structure. Specifically, pressure loss member 166 may have multiple bent portions attached to preheating inlet passage 152. Although not shown in detail, cathode system device 18 includes cathode auxiliary equipment. These include an air filter, a gas-liquid separator, and valves (other than those described above).

[0105] The cooling device 20 includes a coolant supply path 170, a coolant discharge path 172, and a radiator 174. The coolant supply path 170 supplies coolant stored in a coolant tank (not shown) to the coolant inlet 42a of the fuel cell stack 12. The coolant discharged from the coolant outlet 42b of the fuel cell stack 12 is directed to the coolant discharge path 172. The radiator 174 cools the coolant directed to the coolant discharge path 172 by dissipating heat. The coolant cooled by the radiator 174 returns to the coolant supply path 170.

[0106] A refrigerant pump 176 and an intercooler inlet line 178 are provided in the cooling medium supply line 170. The refrigerant pump 176 delivers the cooling medium to the fuel cell stack 12. Furthermore, the refrigerant pump 176 also delivers the cooling medium to the intercooler 156 and other components. The intercooler inlet line 178 is connected to the cooling medium supply line 170 downstream of the refrigerant pump 176. The intercooler inlet line 178 guides the cooling medium flowing through the cooling medium supply line 170 to the intercooler 156.

[0107] An intercooler lead-out path 179 is connected to the cooling medium discharge path 172. The intercooler lead-out path 179 guides the cooling medium flowing through the intercooler 156 to the cooling medium discharge path 172. The cooling device 20 includes cooling system auxiliary equipment. The cooling system auxiliary equipment includes a cooling medium tank, a filter, and the like.

[0108] The circuit for cooling the fuel cell stack 12 and the circuit for cooling the intercooler 156 may be separate systems. In this case, the refrigerant pump 176 and the pump for circulating the cooling medium in the intercooler 156 are provided separately.

[0109] Such a fuel cell system 10 includes a control unit 180 (ECU) that controls the operation of each component of the fuel cell system 10 and enables the fuel cell stack 12 to generate power. The control unit 180 is a computer, such as a microcomputer, and includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and other memory components. The CPU reads and executes programs stored in the ROM, thereby functioning as a various function implementation unit (function implementation means).

[0110] The output signal of the temperature sensor 182 for detecting the temperature of the junction spacer 52 (the first spacer member 48 or the second spacer member 50) is input to the control unit 180. The temperature sensor 182 is a contact temperature sensor directly provided on the junction spacer 52. For example, a thermocouple, a thermistor, or the like is used as such a temperature sensor 182.

[0111] Preferably, the temperature sensor 182 detects the temperature of the portion of the fuel cell stack 12 that is most difficult to heat up when the fuel cell stack 12 is preheated. Figure 2 As shown, the temperature sensor 182 detects the temperature of the lower end portion of the joining spacer 52 closest to the second end panel 30b (the joining spacer 52 adjacent to the second insulating plate 28b).

[0112] The temperature sensor 182 is attached to the junction separator 52. The temperature sensor 182 may detect the temperature of the junction separator 52 closest to the first end panel 30a. Alternatively, the temperature sensor 182 may detect the temperature of the junction separator 52 located in the middle portion of the stacking direction of the cell stack 24. Furthermore, the temperature sensor 182 may detect the temperature of the upper end portion (the end in the direction of arrow C2) or the side end portion (the end in the direction of arrow B) of the junction separator 52. The temperature sensor 182 may also be a non-contact temperature sensor such as an infrared temperature sensor.

[0113] The temperature sensor 182 may be attached to the stack case 14 so as to detect the temperature of the case internal space S. In this case, the temperature sensor 182 can be attached to the stack case 14 more easily than attaching the temperature sensor 182 to the junction spacer 52 .

[0114] exist Figure 1 In FIG. 1 , the control unit 180 includes a compressor control unit 184 , a valve control unit 186 , a pump control unit 188 , a temperature determination unit 190 , and a storage unit 192 .

[0115] Compressor control unit 184 controls the operation of compressor 154. Valve control unit 186 controls the operation of multiple valves (such as switching valve 158, back pressure valve 162, and bypass valve 164). Pump control unit 188 controls the operation of refrigerant pump 176. Temperature determination unit 190 determines whether the temperature T detected by temperature sensor 182 is below a predetermined temperature threshold value Ta. Temperature threshold value Ta is preset and stored in storage unit 192.

[0116] like Figure 9As shown, the temperature threshold value Ta is set based on the relationship between the temperature of the first rubber seal 94 and the second rubber seal 112 of the fuel cell stack 12 and the amount of leakage (leakage) of fuel gas from the fuel cell stack 12. In the following description, the first rubber seal 94 and the second rubber seal 112 may be simply referred to as "rubber seals 194."

[0117] For example, when the rubber seal 194 is made of foamed fluororubber, when the fuel cell stack 12 is first started, Figure 9 As shown by the dotted line L1 in FIG, the fuel gas leaks in the temperature range lower than the temperature T0. However, as the fuel cell stack 12 is used for a longer time, the surface pressure of the rubber seal 194 decreases due to creep of the rubber seal 194. Figure 9 As shown by the solid line L2 in FIG. 3 , the fuel gas leakage start temperature T1 is higher than the temperature T0 .

[0118] Therefore, in this embodiment, the temperature threshold value Ta is set to a temperature of the bonded separator 52 such that the leakage of the fuel gas after the creep of the rubber seal 194 begins to occur at the temperature T1. Furthermore, the temperature threshold value Ta is lower than 0°C.

[0119] Next, a low-temperature startup method of the fuel cell system 10 will be described.

[0120] like Figure 10A As shown, in the low-temperature startup method of the fuel cell system 10 , first, the control unit 180 obtains the detected temperature T of the temperature sensor 182 (step S1 ).

[0121] Next, the temperature determination unit 190 determines whether the detected temperature T is below the temperature threshold Ta (step S2). If the detected temperature T is below the temperature threshold Ta (step S2: Yes), there is a possibility of fuel gas leakage from the rubber seal 194, so the preheating process is started (step S3). If the detected temperature T is higher than the temperature threshold Ta (step S2: No), the power generation process is started (step S10).

[0122] Specifically, if Figure 10B As shown, during the preheating process, the valve control unit 186 sets the switching valve 158 (three-way valve 160) to the second state (step S4). As a result, the upstream flow path 146a and the bypass flow path 150 are connected to each other, and the downstream flow path 146b is blocked from connecting to the upstream flow path 146a and the downstream flow path 146b is blocked from connecting to the bypass flow path 150.

[0123] In addition, the valve control unit 186 controls the bypass valve 164 to be in a closed state (step S5). Furthermore, the pump control unit 188 stops driving the refrigerant pump 176 (step S6). Thereafter, the compressor control unit 184 drives the compressor 154 (step S7). Furthermore, during the warm-up process, the valve control unit 186 controls the supply valve of the fuel gas tank 140 to be in a closed state. Therefore, fuel gas is not supplied from the fuel gas tank 140 to the fuel cell stack 12.

[0124] In this way, Figure 11 As shown, the oxidant gas (air having a higher temperature than the outside air) discharged from the compressor 154 passes through the intercooler 156. At this time, the driving of the refrigerant pump 176 is stopped, so that the cooling medium does not flow into the intercooler 156, thereby preventing the oxidant gas from being cooled by the intercooler 156.

[0125] The oxidant gas that has passed through the intercooler 156 is directed to the preheating inlet passage 152 via the switching valve 158 (three-way valve 160) and the bypass passage 150. Since the bypass valve 164 is closed at this time, the oxidant gas directed to the bypass passage 150 is not discharged into the oxidant gas discharge passage 148. Furthermore, the oxidant gas directed to the preheating inlet passage 152 is further heated while passing through the pressure drop component 166 (throttle portion 168) and is then directed to the inlet port 136 of the stack casing 14.

[0126] like Figure 2 as well as Figure 3 As shown, the oxidant gas introduced into the inlet interface 136 of the stack casing 14 diffuses in the casing internal space S in the width direction of the stack casing 14 (in the direction of arrow B). The oxidant gas then flows in the casing internal space S from one end of the stack casing 14 toward the other end (in the direction of arrow A2) and upward (in the direction of arrow C2). This directly heats the rubber seals 194 of each power generation cell 22 due to the oxidant gas, effectively increasing the temperature of the rubber seals 194. The oxidant gas that has flowed to the other end of the stack casing 14 (in the direction of arrow A2) is then discharged to the exterior of the stack casing 14 through the outlet interface 138.

[0127] In addition, Figure 10B In step S8 , the temperature determination unit 190 determines whether the detected temperature T is higher than the temperature threshold value Ta (step S8 ). If the detected temperature T is lower than the temperature threshold value Ta (step S8 : No), the process of step S8 is repeated.

[0128] If the detected temperature T is higher than the temperature threshold Ta (step S8: Yes), the control unit 180 maintains the preheating process for only the predetermined heating time (step S9). In other words, the control unit 180 continues the preheating process until the time elapsed after the detected temperature T exceeds the temperature threshold Ta reaches the predetermined heating time.

[0129] Because the fuel cell stack 12 has a relatively large heat capacity, it takes longer for its temperature to rise compared to the area surrounding the fuel cell stack 12 (the space within the casing S). Consequently, there is a possibility that the entire fuel cell stack 12 (all rubber seals 194) may not have been sufficiently heated by the time the temperature T detected by the temperature sensor 182 exceeds the temperature threshold Ta. Therefore, to keep the temperature of all rubber seals 194 above the aforementioned leakage start temperature T1, the preheating process is continued even after the detected temperature T exceeds the temperature threshold Ta.

[0130] Afterwards, if Figure 10A As shown, the power generation process (step S10) is performed. Specifically, during the power generation process, the valve control unit 186 switches the switching valve 158 to the first state. This causes the upstream flow path 146a and the downstream flow path 146b to communicate with each other, and the bypass flow path 150 is blocked from communicating with the upstream flow path 146a and the downstream flow path 146b.

[0131] Therefore, if Figure 12 As shown, the oxidant gas ejected from the compressor 154 is supplied to the oxidant gas inlet 40a of the fuel cell stack 12. At this time, the oxidant gas does not flow in the bypass flow path 150.

[0132] Furthermore, the controller 180 opens the supply valve of the fuel gas tank 140 . As a result, the fuel gas in the fuel gas tank 140 is supplied to the fuel gas inlet 44 a of the fuel cell stack 12 via the fuel gas supply path 142 .

[0133] Furthermore, the pump control unit 188 drives the coolant pump 176 , so that the coolant in the coolant tank (not shown) is supplied to the coolant inlet 42 a of the fuel cell stack 12 by the coolant pump 176 .

[0134] Furthermore, the coolant discharged from refrigerant pump 176 is guided from intercooler inlet passage 178 to intercooler 156. After circulating through intercooler 156, the coolant returns to coolant discharge passage 172 via intercooler outlet passage 179. Thus, the oxidant gas discharged from compressor 154 is cooled in intercooler 156. The coolant returned to coolant discharge passage 172 is cooled in radiator 174 and then guided to coolant supply passage 170.

[0135] like Figure 4 、 Figure 5 as well as Figure 7 As shown, the oxidant gas supplied to the oxidant gas inlet 40a is introduced from the oxidant gas supply passage 72a into the oxidant gas flow path 80 of the first separator member 48. After being introduced into the oxidant gas flow path 80, the oxidant gas moves along the oxidant gas flow path 80 in the direction of arrow B and is supplied to the first electrode 60 of the MEA 54.

[0136] like Figure 4 、 Figure 5 as well as Figure 8 As shown, the fuel gas supplied to the fuel gas inlet 44a is introduced from the fuel gas supply passage 76a into the fuel gas flow path 98 of the second separator body 96. After being introduced into the fuel gas flow path 98, the fuel gas moves in the direction of arrow B along the fuel gas flow path 98 and is supplied to the second electrode 62 of the MEA 54.

[0137] Therefore, in each MEA 54, the oxidant gas supplied to the first electrode 60 and the fuel gas supplied to the second electrode 62 are consumed by electrochemical reactions within the first electrode catalyst layer 64 and the second electrode catalyst layer 68. As a result, power generation is performed.

[0138] Then, in Figure 1 、 Figure 4 as well as Figure 5 In the embodiment of the present invention, the oxidant exhaust gas supplied to and consumed by the first electrode 60 flows from the oxidant gas flow path 80 to the oxidant gas discharge passage 72b. After flowing through the oxidant gas discharge passage 72b, the oxidant gas is discharged from the oxidant gas outlet 40b to the oxidant gas discharge passage 148. The fuel exhaust gas supplied to and consumed by the second electrode 62 flows from the fuel gas flow path 98 to the fuel gas discharge passage 76b. After flowing through the fuel gas discharge passage 76b, the fuel gas is discharged from the fuel gas outlet 44b to the fuel gas discharge passage 144.

[0139] In addition, Figure 5 In the embodiment, the cooling medium supplied to the cooling medium supply passage 74a is introduced into the cooling medium flow path 114 formed between the first separator member 48 and the second separator member 50. After being introduced into the cooling medium flow path 114, the cooling medium flows in the direction of arrow symbol B. After cooling the MEA 54, the cooling medium flows to the cooling medium discharge passage 74b. After flowing through the cooling medium discharge passage 74b, the cooling medium is discharged from the cooling medium outlet 42b to the cooling medium discharge passage 172 (see FIG. Figure 1 、 Figure 4 as well as Figure 5). After the power generation process, a series of action processes are completed.

[0140] This embodiment achieves the following effects.

[0141] According to the fuel cell system 10 of this embodiment, when the multiple power generation cells 22 are generating electricity in a low-temperature environment, the switching valve 158 is set to the second state and the compressor 154 is driven. This allows the relatively high-temperature oxidant gas discharged from the compressor 154 to be introduced into the housing interior space S while being heated by the pressure loss member 166. This allows the rubber seal 194 of the fuel cell stack 12 to be efficiently heated. Furthermore, by setting the switching valve 158 to the first state while the rubber seal 194 is sufficiently heated, the oxidant gas discharged from the compressor 154 is supplied to the fuel cell stack 12, enabling the multiple power generation cells 22 to commence power generation. Thus, the rubber seal 194 can be efficiently heated using a simple structure. This effectively prevents fuel gas from leaking from the rubber seal 194 when the multiple power generation cells 22 are generating electricity in a low-temperature environment.

[0142] According to the low-temperature startup method of the fuel cell system 10 of this embodiment, a preheating process is performed, in which the relatively high-temperature oxidant gas ejected from the compressor 154 is circulated through the pressure loss component 166 and introduced into the housing interior space S in a heated state to preheat the fuel cell stack 12. Therefore, the rubber seal 194 of the fuel cell stack 12 can be efficiently heated in a low-temperature environment. Furthermore, after the preheating process, a power generation process is performed, in which the oxidant gas ejected from the compressor 154 is supplied to each power generation cell 22, and fuel gas is supplied to each power generation cell 22, thereby starting power generation. Thus, the rubber seal 194 can be efficiently heated using a simple structure. As a result, it is possible to effectively suppress leakage of fuel gas from the rubber seal 194 when multiple power generation cells 22 are generating power in a low-temperature environment.

[0143] The pressure loss member 166 includes a throttle portion 168 having a flow path cross-sectional area smaller than the flow path cross-sectional area of the oxidizing gas supply path 146 .

[0144] According to such a configuration, the pressure loss of the oxidizing gas can be increased with a simple structure.

[0145] The stack casing 14 includes an inlet port 136 and an outlet port 138 . The inlet port 136 introduces the oxidant gas guided from the preheating inlet passage 152 into the casing interior space S. The outlet port 138 discharges the gas in the casing interior space S to the outside of the stack casing 14 .

[0146] In the preheating process, oxidant gas is introduced into the casing inner space S from the inlet port 136 of the stack casing 14 , and the gas in the casing inner space S is discharged to the outside of the stack casing 14 from the outlet port 138 of the stack casing 14 .

[0147] In this case, the gas in the casing inner space S is led out from the outlet interface 138 to the outside of the stack casing 14 . Therefore, the oxidant gas can be efficiently introduced into the casing inner space S from the inlet interface 136 .

[0148] The inlet interface 136 is located at the lower portion of the stack housing 14 , and the outlet interface 138 is located at the upper portion of the stack housing 14 .

[0149] With this configuration, the oxidant gas introduced into the casing inner space S from the inlet port 136 can flow from the lower portion to the upper portion of the stack casing 14. This allows the entire fuel cell stack 12 to be efficiently heated.

[0150] The inlet interface portion 136 is located at one end portion of the stack case 14 in the stacking direction. The outlet interface portion 138 is located at the other end portion of the stack case 14 in the stacking direction.

[0151] With this configuration, the oxidant gas introduced from the inlet port 136 into the casing inner space S can flow from one end toward the other end of the stack casing 14. This allows the entire fuel cell stack 12 to be efficiently heated.

[0152] The fuel cell system 10 includes a temperature sensor 182 that detects the temperature of the junction separator 52 located farthest from the inlet port 136. A warm-up process is performed when the temperature T detected by the temperature sensor 182 is below a temperature threshold Ta, and a power generation process is performed after the detected temperature T exceeds the temperature threshold Ta.

[0153] According to such a method, the power generation process can be performed after the temperature of the rubber seal 194 is raised to a temperature higher than the leakage occurrence start temperature T1.

[0154] The fuel cell system 10 includes an oxidant gas exhaust passage 148, a bypass passage 150, and a bypass valve 164. The oxidant gas exhaust passage 148 discharges the oxidant gas from the fuel cell stack 12 after flowing through each power generation cell 22. The bypass passage 150 connects the oxidant gas exhaust passage 148 to the oxidant gas supply passage 146. The bypass valve 164 opens and closes the bypass passage 150. The bypass passage 150 includes a first end connected to the oxidant gas supply passage 146 and a second end connected to the oxidant gas exhaust passage 148. The preheating inlet passage 152 is connected to the portion of the bypass passage 150 between the bypass valve 164 and the first end of the bypass passage 150.

[0155] In the preheating process, the oxidant gas discharged from the compressor 154 is introduced into the housing interior space S via the oxidant gas supply path 146 , the bypass flow path 150 , and the preheating introduction path 152 . Furthermore, in the preheating process, the bypass valve 164 is closed to block the bypass flow path 150 .

[0156] In this case, the oxidizing gas discharged from compressor 154 can be guided to preheating inlet passage 152 via switching valve 158 and bypass passage 150 using a simple configuration. Furthermore, by closing bypass valve 164 at this time, the oxidizing gas can be prevented from being discharged into oxidizing gas discharge passage 148.

[0157] The fuel cell system 10 includes an intercooler 156 and a refrigerant pump 176. Intercooler 156 is installed upstream of the connection with bypass flow path 150 in oxidant gas supply path 146 and cools the oxidant gas. Refrigerant pump 176 circulates the cooling medium within intercooler 156. During the warm-up process, refrigerant pump 176 is stopped. During the power generation process, refrigerant pump 176 is driven.

[0158] According to such a method, during the warm-up process, the oxidant gas discharged from the compressor 154 can be prevented from being cooled by the intercooler 156. Furthermore, during the power generation process, the oxidant gas discharged from the compressor 154 can be appropriately cooled.

[0159] Next, a stack case 14a according to a modified example will be described. In the stack case 14a, the same components as those of the stack case 14 described above are denoted by the same reference numerals, and their description will be omitted.

[0160] like Figure 13 as well as Figure 14 As shown, in the stack casing 14a, the inlet interface 136 is located at the lower wall 122. The inlet interface 136 is located between the center of the stack casing 14a in the stacking direction and one end of the stack casing 14a (the first end wall 128). Specifically, the inlet interface 136 is located below one end of the cell stack 24. The opening 200 of the inlet interface 136 on the side of the casing internal space S faces the center of the width direction (the direction indicated by arrow B) of the cell stack 24.

[0161] In such a stack case 14 a , the opening 200 of the introduction interface portion 136 on the case internal space S side faces the cell stack 24 .

[0162] According to such a configuration, the oxidizing gas introduced from the introduction interface portion 136 can be directly introduced into the cell stack 24. Thus, the temperature of the rubber seal 194 can be efficiently increased by the oxidizing gas.

[0163] (Second embodiment)

[0164] Next, a fuel cell system 10A according to a second embodiment of the present invention will be described. Components of the fuel cell system 10A according to the second embodiment that are identical to those of the above-described fuel cell system 10 are denoted by the same reference numerals, and their description will be omitted.

[0165] like Figure 15 As shown, the fuel cell system 10A includes a fuel cell stack 12 a , a stack casing 14 b , an anode system device 16 , a cathode system device 18 a , and a cooling device 20 .

[0166] exist Figure 16 In the fuel cell stack 12a, a single cell stack 24 is provided, along with a first wiring member 26a, a first insulating plate 28a, a first end plate 30a, a second wiring member 26b, a second insulating plate 28b, and a second end plate 30b. Single cell stack 24 includes a plurality of stacked power-generating cells 22. Second insulating plate 28b and second end plate 30b have preheating oxidant gas outlets 202 for discharging oxidant gas from oxidant gas supply passages 72a to the exterior of fuel cell stack 12a.

[0167] The fuel cell stack 12a has an outlet valve 204 that can be switched between a first state and a second state. In the first state, the outlet valve 204 allows the oxidant gas to be discharged from the preheating oxidant gas outlet 202 to the outside. In the second state, the outlet valve 204 blocks the oxidant gas from being discharged from the preheating oxidant gas outlet 202 to the outside. The outlet valve 204 is provided on the second end panel 30b. In addition, the valve control unit 186 (see Figure 15 ) controls the action of the export valve 204.

[0168] The stack housing 14b includes a cover 206, a first end panel 30a, and a second end panel 30b. The cover 206 covers the cell stack 24 from a direction perpendicular to the stacking direction (the direction indicated by arrows B and C). The first end panel 30a and the second end panel 30b are part of the stack housing 14b. The cover 206 includes, for example, four panels 208. Each panel 208 is secured to the side of the first end panel 30a and the side of the second end panel 30b by bolts (not shown). However, the cover 206 may also be extruded integrally into a quadrangular cylindrical shape.

[0169] like Figure 15As shown, cathode system device 18a includes an oxidant gas supply line 146, an oxidant gas exhaust line 148, and a bypass flow path 150. A compressor 154, an intercooler 156, and an on-off valve 210 are installed in oxidant gas supply line 146. On-off valve 210 is installed in downstream flow path 146b. Specifically, on-off valve 210 can switch between an open state, which opens downstream flow path 146b, and a closed state, which blocks downstream flow path 146b. The valve control unit 186 controls the operation of on-off valve 210.

[0170] The low-temperature startup method of the fuel cell system 10A according to the present embodiment differs only in the warm-up step from the low-temperature startup method of the above-described fuel cell system 10. Therefore, the warm-up step will be described below.

[0171] like Figure 17 As shown, during the preheating process, the valve control unit 186 puts the on-off valve 210 and the outlet valve 204 into an open valve state (step S11). In addition, the valve control unit 186 puts the bypass valve 164 and the back pressure valve 162 into a closed valve state (step S12). In addition, the pump control unit 188 stops driving the refrigerant pump 176 (step S13). Then, the compressor control unit 184 drives the compressor 154 (step S14). Moreover, during the preheating process, the valve control unit 186 controls the supply valve of the fuel gas tank 140 to be in a closed valve state. Therefore, fuel gas is not supplied to the fuel cell stack 12a from the fuel gas tank 140.

[0172] Thus, the oxidant gas (air having a higher temperature than the outside air) discharged from the compressor 154 passes through the intercooler 156. At this time, the driving of the refrigerant pump 176 is stopped, so that the cooling medium does not flow into the intercooler 156, thereby suppressing the cooling of the oxidant gas by the intercooler 156.

[0173] The oxidizing gas that has passed through the intercooler 156 is supplied to the oxidizing gas inlet 40a via the downstream flow path 146b. At this time, the bypass valve 164 is closed, so the oxidizing gas is not discharged to the oxidizing gas discharge path 148.

[0174] like Figure 16As shown, the oxidant gas ejected from the compressor 154 and supplied to the oxidant gas inlet 40a flows through the oxidant gas supply passage 72a toward the second end panel 30b (in the direction of arrow A2). After flowing through the oxidant gas supply passage 72a, the oxidant gas is discharged to the outside of the fuel cell stack 12a (outside the stack casing 14b) via the preheating oxidant gas outlet 202 and the outlet valve 204. At this time, the back pressure valve 162 is in a closed state, thereby suppressing the flow of the oxidant gas from the oxidant gas supply passage 72a to the oxidant gas flow path 80 (power generation area 23). This prevents the electrolyte membrane 58 from being excessively dried out by the oxidant gas. In addition, it prevents the catalyst of the first electrode catalyst layer 64 from being degraded by the oxidant gas.

[0175] The oxidant gas flowing through the oxidant gas supply passage 72 a raises the temperature of the entire fuel cell stack 12 a , thereby efficiently raising the temperature of the rubber seal 194 of each power generating cell 22 .

[0176] Afterwards, proceed Figure 17 The processing of step S15 and step S16 is the same as that of the above step S15 and step S16. Figure 10B The processing of step S8 and step S9 is the same, so their description is omitted.

[0177] According to the fuel cell system 10A of this embodiment, when multiple power generation cells 22 are generating electricity in a low-temperature environment, the outlet valve 204 is set to the first position and the compressor 154 is driven. This allows the relatively high-temperature oxidant gas discharged from the compressor 154 to flow through the oxidant gas supply passage 72a. This effectively raises the temperature of the rubber seal 194 of the fuel cell stack 12a. Furthermore, when the rubber seal 194 is sufficiently heated, the outlet valve 204 is set to the second position. This allows the oxidant gas discharged from the compressor 154 to be supplied to the power generation area 23 of each power generation cell 22. This allows the multiple power generation cells 22 to start generating electricity. Thus, the rubber seal 194 can be efficiently heated with a simple structure. This effectively prevents fuel gas from leaking from the rubber seal 194 when multiple power generation cells 22 are generating electricity in a low-temperature environment.

[0178] According to the low-temperature startup method of the fuel cell system 10A according to this embodiment, a warm-up step is performed, in which the outlet valve 204 is set to the first position to allow the relatively high-temperature oxidant gas discharged from the compressor 154 to flow through the oxidant gas supply passage 72a, thereby preheating the fuel cell stack 12a. Consequently, the rubber seal 194 of the fuel cell stack 12a can be efficiently heated in a low-temperature environment. Following the warm-up step, a power generation step is performed, in which the outlet valve 204 is set to the second position to supply the oxidant gas discharged from the compressor 154 to the power generation region 23 of each power generation cell 22, and fuel gas is also supplied to the power generation region 23 of each power generation cell 22, thereby starting power generation. Thus, the rubber seal 194 can be efficiently heated with a simple structure. This effectively prevents fuel gas from leaking from the rubber seal 194 when multiple power generation cells 22 generate power in a low-temperature environment.

[0179] The fuel cell system 10A includes an oxidant gas exhaust passage 148 and a backpressure valve 162. The oxidant gas exhaust passage 148 discharges the oxidant gas from the fuel cell stack 12a after flowing through the plurality of power generation cells 22. The backpressure valve 162 opens and closes the oxidant gas exhaust passage 148. During the warm-up process, the backpressure valve 162 is in a closed state, blocking the oxidant gas exhaust passage 148.

[0180] According to this method, by keeping backpressure valve 162 closed during the preheating process, it is possible to prevent the oxidant gas flowing through oxidant gas supply passage 72a from being directed to power generation region 23 (oxidant gas flow path 80). This prevents the electrolyte membrane 58 from being excessively dried out by the oxidant gas during the preheating process. Furthermore, it is possible to prevent the catalyst in first electrode catalyst layer 64 from being degraded by the oxidant gas.

[0181] (Third embodiment)

[0182] Next, a fuel cell system 10B according to a third embodiment of the present invention will be described. Components of the fuel cell system 10B according to the third embodiment that are identical to those of the above-described fuel cell system 10 are denoted by the same reference numerals, and their description will be omitted.

[0183] like Figure 18As shown, the fuel cell system 10B includes a stack casing 14, an anode system device 16, a cathode system device 18b, and a cooling device 20. The cathode system device 18b includes a switching unit 220 that can switch between a first state and a second state. In the first state, the switching unit 220 allows the supply of oxidant gas from the oxidant gas supply path 146 into the fuel cell stack 12 and blocks the supply of oxidant gas from the oxidant gas supply path 146 into the casing inner space S via the preheating inlet path 152. In the second state, the switching unit 220 blocks the supply of oxidant gas from the oxidant gas supply path 146 into the fuel cell stack 12 and allows the supply of oxidant gas from the oxidant gas supply path 146 into the casing inner space S via the preheating inlet path 152.

[0184] Switching unit 220 includes an on-off valve 222 and a bypass valve 224. On-off valve 222 is attached to downstream flow path 146b. Bypass valve 224 is attached to the connection between bypass flow path 150 and preheating inlet path 152. In the first state of switching unit 220, on-off valve 222 opens downstream flow path 146b. In the second state of switching unit 220, on-off valve 222 blocks downstream flow path 146b.

[0185] The bypass valve 224 is a three-way valve. In the first state of the switching unit 220, the bypass valve 224 connects the flow path 150a between the bypass valve 224 and the oxidant gas supply path 146 in the bypass flow path 150 with the preheating introduction path 152, blocks the flow path 150a from communicating with the flow path 150b between the bypass valve 224 and the oxidant gas exhaust path 148 in the bypass flow path 150, and blocks the flow path 150b from communicating with the preheating introduction path 152. In the second state of the switching unit 220, the bypass valve 224 connects the flow path 150a with the preheating introduction path 152, blocks the flow path 150a from communicating with the flow path 150b, and blocks the flow path 150b from communicating with the preheating introduction path 152.

[0186] In this embodiment, during the preheating process, valve control unit 186 controls on-off valve 222 and bypass valve 224 so that switching unit 220 is in the second state. Consequently, oxidant gas (air with a higher temperature than the outside air) discharged from compressor 154 is guided to preheating inlet passage 152 via intercooler 156, flow passage 150a, and bypass valve 224. Consequently, this embodiment achieves the same effects as the fuel cell system 10 according to the first embodiment described above.

[0187] Furthermore, the present invention is not limited to the above-described embodiment, and various configurations are possible without departing from the gist of the present invention.

[0188] The above embodiments are summarized as follows.

[0189] The above embodiment discloses a fuel cell system comprising: a fuel cell stack (12, 12a) having a cell stack 24 formed by stacking a plurality of power generation cells 22, wherein the plurality of power generation cells include an MEA component 46 for generating electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components (48, 50) arranged on both sides of the MEA component; a stack casing (14, 14a, 14b) for accommodating the fuel cell stack; an oxidant gas supply path 146 for supplying the oxidant gas to the fuel cell stack; Oxidant gas; and a compressor 154, which is arranged in the oxidant gas supply path, the two partition members each have a metal partition body (78, 96), the sealing protrusion (92, 110) is integrally formed with the partition body, the sealing protrusion is used to prevent the fluid as the oxidant gas, the fuel gas or the cooling medium from leaking, the sealing protrusion protrudes from the partition body in the stacking direction of the plurality of power generation cells, and the rubber seal 194 is clamped on the top of the sealing protrusion (92a, 11 0a) and the MEA component, in the fuel cell system (10, 10A, 10B), there are: a preheating inlet path 152, which is used to introduce the oxidant gas ejected from the compressor to the oxidant gas supply path into the shell inner space S between the stack shell and the fuel cell stack; and a switching part (158, 220), which can switch between a first state and a second state, the first state is a state in which the oxidant gas is allowed to be supplied from the oxidant gas supply path to the fuel cell stack and the oxidant gas is blocked from being introduced from the oxidant gas supply path to the shell inner space, and the second state is a state in which the oxidant gas is blocked from being supplied from the oxidant gas supply path to the fuel cell stack and the oxidant gas is allowed to be introduced from the oxidant gas supply path to the shell inner space via the preheating inlet path, and a pressure loss component 166 is installed in the preheating inlet path, and the pressure loss component is used to increase the pressure loss of the oxidant gas flowing through the preheating inlet path.

[0190] In the above-described fuel cell system, the pressure loss member may include a throttle portion 168 having a flow path cross-sectional area smaller than a flow path cross-sectional area of the oxidant gas supply path.

[0191] In the above-mentioned fuel cell system, the stack shell may also include: an inlet interface portion 136, which is used to introduce the oxidant gas guided from the preheating inlet path into the space inside the shell; and an outlet interface portion 138, which is used to discharge the gas in the space inside the shell to the outside of the stack shell.

[0192] In the above-mentioned fuel cell system, the inlet interface portion may be located at a lower portion of the stack case, and the outlet interface portion may be located at an upper portion of the stack case.

[0193] In the above-mentioned fuel cell system, the inlet interface portion may be located between the center of the stacking direction of the stack shell and one end portion of the stack shell or located at the one end portion of the stack shell, and the outlet interface portion may be located between the center of the stacking direction of the stack shell and the other end portion of the stack shell or located at the other end portion of the stack shell.

[0194] In the above-described fuel cell system, the opening 200 of the introduction interface portion, which is in communication with the space within the casing, may face the single cell stack.

[0195] In the above-mentioned fuel cell system, it may also be equipped with: an oxidant gas exhaust path 148, which is used to discharge the oxidant exhaust gas from the fuel cell stack after circulating through the multiple power generation cells; a bypass flow path 150, which connects the oxidant gas exhaust path with the oxidant gas supply path; and a bypass valve 164, which opens and closes the bypass flow path, and the bypass flow path includes: a first end connected to the oxidant gas supply path; and a second end connected to the oxidant gas exhaust path, and the preheating inlet path is connected to the part between the bypass valve and the first end in the bypass flow path.

[0196] In the above fuel cell system, the rubber seal may be made of porous fluororubber.

[0197] The above embodiment discloses a fuel cell system, comprising: a fuel cell stack, which has a single cell stack formed by stacking a plurality of power generation cells, a first end plate 30a arranged at one end of the single cell stack, and a second end plate 30b arranged at the other end of the single cell stack, the plurality of power generation cells including an MEA component that generates electricity by an electrochemical reaction between an oxidant gas and a fuel gas, two separator components arranged on both sides of the MEA component; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged in the oxidant gas supply path, the two separator components each having a metal separator body, a sealing protrusion integrally formed with the separator body, the sealing protrusion being used to prevent leakage of a fluid serving as the oxidant gas, the fuel gas or the cooling medium, the sealing protrusion protruding from the separator body in the stacking direction of the plurality of power generation cells, and a rubber seal being clamped therein. Between the top of the sealing protrusion and the MEA component, each of the multiple power generation cells has an oxidant gas supply connecting hole 72a for supplying the oxidant gas to the power generation area 23 of the multiple power generation cells. In the fuel cell system, the first end panel has an oxidant gas inlet 40a for introducing the oxidant gas from the oxidant gas supply path to the oxidant gas supply connecting hole, and the second end panel has a preheating oxidant gas outlet 202 for exporting the oxidant gas from the oxidant gas supply connecting hole to the outside of the fuel cell stack. The fuel cell stack has an export valve 204 that can switch between a first state and a second state. The first state is a state that allows the oxidant gas to be exported from the preheating oxidant gas outlet to the outside of the fuel cell stack, and the second state is a state that blocks the export of the oxidant gas from the preheating oxidant gas outlet to the outside of the fuel cell stack.

[0198] The above embodiment discloses a low-temperature start-up method for a fuel cell system, wherein the fuel cell system comprises: a fuel cell stack having a single cell stack formed by stacking a plurality of power generation cells, wherein the plurality of power generation cells include an MEA component for generating electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components arranged on both sides of the MEA component; a stack casing for accommodating the fuel cell stack; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged in the oxidant gas supply path, wherein the two separator components each have a metal separator body, a sealing protrusion integrally formed with the separator body, and the sealing protrusion is used to prevent the oxidant gas, the fuel gas, from being heated by the gas. The fuel gas or cooling medium fluid leaks, the sealing protrusion protrudes from the partition body in the stacking direction of the multiple power generation cells, and the rubber seal is sandwiched between the top of the sealing protrusion and the MEA component. In the low-temperature startup method of the fuel cell system, it includes: a preheating process, allowing the oxidant gas ejected from the compressor to flow through the pressure loss component and be introduced into the shell space between the stack shell and the fuel cell stack in a heated state to preheat the fuel cell stack; and a power generation process, after the preheating process, supplying the oxidant gas ejected from the compressor to the multiple power generation cells and supplying the fuel gas to the multiple power generation cells to start power generation.

[0199] In the above-mentioned low-temperature startup method of the fuel cell system, it may also be that, in the preheating process, the oxidant gas is introduced into the space inside the shell from the inlet interface portion of the stack shell and the gas in the space inside the shell is discharged to the outside of the stack shell from the outlet interface portion of the stack shell.

[0200] In the above-mentioned low-temperature startup method of the fuel cell system, the inlet interface portion may be provided at a lower portion of the stack casing, and the outlet interface portion may be provided at an upper portion of the stack casing.

[0201] In the above-mentioned low-temperature start-up method of the fuel cell system, the inlet interface portion may be located between the center of the stacking direction of the stack shell and one end portion of the stack shell, or located at the one end portion of the stack shell, and the outlet interface portion may be located between the center of the stacking direction of the stack shell and the other end portion of the stack shell, or located at the other end portion of the stack shell.

[0202] In the above-mentioned low-temperature start-up method of the fuel cell system, the fuel cell system may also have a temperature sensor 182, which detects the temperature of the partition member located at the position farthest from the inlet interface part, and performs the preheating process when the detection temperature T of the temperature sensor is below the temperature threshold Ta, and performs the power generation process after the detection temperature is higher than the temperature threshold.

[0203] In the above-mentioned low-temperature start-up method of the fuel cell system, the fuel cell system may also include: an oxidant gas exhaust path, which is used to discharge the oxidant exhaust gas from the fuel cell stack after circulating through the multiple power generation cells; a bypass flow path, which connects the oxidant gas exhaust path with the oxidant gas supply path; and a preheating inlet path, which connects the bypass flow path with the stack shell, and in the preheating process, the oxidant gas ejected from the compressor is guided to the space inside the shell via the oxidant gas supply path, the bypass flow path and the preheating inlet path.

[0204] In the above-mentioned low-temperature start-up method of the fuel cell system, a bypass valve for opening and closing the bypass flow path is installed in the bypass flow path, and the preheating inlet path is connected between the bypass valve and the oxidant gas supply path in the bypass flow path. During the preheating process, the bypass valve is set to a closed valve state for closing the bypass flow path.

[0205] In the above-mentioned low-temperature start-up method of the fuel cell system, the fuel cell system may also include: an intercooler 156, which is installed in the oxidant gas supply path upstream of the connection portion with the bypass flow path to cool the oxidant gas; and a refrigerant pump 176, which allows the cooling medium to circulate in the intercooler, stops driving the refrigerant pump in the preheating process, and drives the refrigerant pump in the power generation process.

[0206] The above embodiment discloses a low-temperature start-up method for a fuel cell system, wherein the fuel cell system comprises: a fuel cell stack having a single cell stack formed by stacking a plurality of power generation cells, a first end plate arranged at one end of the single cell stack, and a second end plate arranged at the other end of the single cell stack, wherein the plurality of power generation cells include an MEA component that generates electricity by an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components arranged on both sides of the MEA component; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; and a compressor arranged at the oxidant gas supply path. The two separator members each have a metal separator body, and the sealing protrusion is integrally formed with the separator body. The sealing protrusion is used to prevent leakage of the fluid serving as the oxidant gas, the fuel gas or the cooling medium. The sealing protrusion protrudes from the separator body in the stacking direction of the multiple power generation cells. The rubber seal is sandwiched between the top of the sealing protrusion and the MEA member. The multiple power generation cells each have an oxidant gas supply connecting hole for supplying the oxidant gas to the power generation area of the multiple power generation cells. During the low temperature startup of the fuel cell system In the method, the first end panel has an oxidant gas inlet for introducing the oxidant gas from the oxidant gas supply path to the oxidant gas supply connecting hole, the second end panel has a preheating oxidant gas outlet for discharging the oxidant gas from the oxidant gas supply connecting hole to the outside of the fuel cell stack, the fuel cell stack has an outlet valve capable of switching between a first state and a second state, the first state being a state allowing the oxidant gas to be discharged from the preheating oxidant gas outlet to the outside of the fuel cell stack, and the second state being a state blocking the discharge of the oxidant gas from the preheating oxidant gas outlet to the outside of the fuel cell stack, the low-temperature start-up method of the fuel cell system includes: a preheating process, in which the outlet valve is set to the first state, the oxidant gas ejected from the compressor is circulated in the oxidant gas supply connecting hole, thereby preheating the fuel cell stack; and a power generation process, in which, after the preheating process, the outlet valve is set to the second state, the oxidant gas ejected from the compressor is supplied to the power generation area of the multiple power generation cells and the fuel gas is supplied to the power generation area of the multiple power generation cells, thereby starting power generation.

[0207] In the above-mentioned low-temperature start-up method of the fuel cell system, the fuel cell system may also include: an oxidant gas exhaust path, which is used to discharge the oxidant exhaust gas from the fuel cell stack after circulating through the multiple power generation cells; and a back pressure valve 162, which opens and closes the oxidant gas exhaust path, and in the preheating process, the back pressure valve is set to a closed valve state to close the oxidant gas exhaust path.

Claims

1. A fuel cell system comprising: A fuel cell stack comprising a single cell stack formed by stacking a plurality of power generation cells, wherein the plurality of power generation cells include an MEA component that generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components disposed on both sides of the MEA component; a stack housing accommodating the fuel cell stack; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; an oxidant gas exhaust path for exhausting the oxidant gas from the fuel cell stack after flowing through the plurality of power generation cells; a bypass flow path connecting the oxidant gas exhaust path and the oxidant gas supply path; and a compressor provided in the oxidant gas supply path, Each of the two partition members has a metal partition body. The sealing protrusion is integrally formed with the separator body, and the sealing protrusion is used to prevent leakage of the fluid serving as the oxidant gas, the fuel gas or the cooling medium. The sealing protrusion protrudes from the separator body in the stacking direction of the plurality of power generation cells. A rubber seal is sandwiched between the top of the sealing protrusion and the MEA component. In the fuel cell system, A shell inner space is provided between the fuel cell stack and the stack shell, The fuel cell system comprises: a preheating inlet passage for introducing the oxidant gas ejected from the compressor to the oxidant gas supply passage from the oxidant gas supply passage into the casing inner space between the stack casing and the fuel cell stack via the bypass flow passage; and a switching portion capable of switching between a first state and a second state, wherein the first state is a state in which the oxidant gas is allowed to be supplied from the oxidant gas supply path to the fuel cell stack and the oxidant gas is blocked from being introduced from the oxidant gas supply path to the space inside the shell via the preheating introduction path, and the second state is a state in which the oxidant gas is blocked from being supplied from the oxidant gas supply path to the fuel cell stack and the oxidant gas is allowed to be introduced from the oxidant gas supply path to the space inside the shell via the preheating introduction path. The downstream flow path of the oxidizing gas supply path, which is located downstream of the connection portion with the bypass flow path, guides the oxidizing gas discharged from the compressor into the power generation area of the plurality of power generation cells. A pressure loss member is attached to the preheating introduction passage. The pressure loss member is configured to increase the pressure loss of the oxidizing gas flowing through the preheating introduction passage.

2. The fuel cell system according to claim 1, wherein: The pressure loss member includes a throttle portion having a flow path cross-sectional area smaller than a flow path cross-sectional area of the oxidizing gas supply path.

3. The fuel cell system according to claim 1, wherein: The stack housing comprises: an introduction interface portion for introducing the oxidant gas guided from the preheating introduction path into the space within the housing; and The outlet interface is used to discharge the gas in the space inside the casing to the outside of the stack casing.

4. The fuel cell system according to claim 3, wherein: The introduction interface is located at the lower part of the stack housing. The outlet interface is located at an upper portion of the stack housing.

5. The fuel cell system according to claim 3, wherein: The introduction interface portion is located between the center of the stack housing in the stacking direction and one end of the stack housing or is located at the one end of the stack housing. The lead-out interface portion is located at a portion between the center of the stack housing in the stacking direction and the other end portion of the stack housing, or at the other end portion of the stack housing.

6. The fuel cell system according to claim 3, wherein: An opening of the introduction interface portion, which communicates with the space within the case, faces the cell stack.

7. The fuel cell system according to any one of claims 1 to 6, characterized in that have: a bypass valve that opens and closes the bypass flow path, The bypass flow path includes: a first end portion connected to the oxidant gas supply path; and a second end portion connected to the oxidant gas discharge path, The preheating introduction passage is connected to a portion of the bypass flow passage between the bypass valve and the first end portion.

8. A low-temperature startup method for a fuel cell system, the fuel cell system comprising: A fuel cell stack comprising a single cell stack formed by stacking a plurality of power generation cells, wherein the plurality of power generation cells include an MEA component that generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas, and two separator components disposed on both sides of the MEA component; a stack housing accommodating the fuel cell stack; an oxidant gas supply path for supplying the oxidant gas to the fuel cell stack; an oxidant gas exhaust path for exhausting the oxidant gas from the fuel cell stack after flowing through the plurality of power generation cells; a bypass flow path connecting the oxidant gas exhaust path and the oxidant gas supply path; and a compressor provided in the oxidant gas supply path, Each of the two partition members has a metal partition body. The sealing protrusion is integrally formed with the separator body, and the sealing protrusion is used to prevent leakage of the fluid serving as the oxidant gas, the fuel gas or the cooling medium. The sealing protrusion protrudes from the separator body in the stacking direction of the plurality of power generation cells. The rubber seal is sandwiched between the top of the sealing protrusion and the MEA component. In the low temperature startup method of the fuel cell system, A shell inner space is provided between the fuel cell stack and the stack shell, The low-temperature starting method of the fuel cell system comprises: a preheating step of causing the oxidant gas discharged from the compressor to flow from the oxidant gas supply path through the bypass flow path and the pressure loss component and to be introduced in a heated state into the casing inner space between the stack casing and the fuel cell stack to preheat the fuel cell stack; as well as The power generation process is to supply the oxidant gas ejected from the compressor to the power generation area of the plurality of power generation cells through the downstream side flow path in the oxidant gas supply path that is downstream of the connection part of the bypass flow path, and to supply the fuel gas to the plurality of power generation cells to start power generation.

Images