Air-cooled fuel cell system

Abstract

The present invention provides an air-cooled fuel cell system capable of efficiently preheating a fuel cell. The air-cooled fuel cell system is characterized in that it includes a fuel cell, a reaction air supply unit that supplies reaction air to the reaction air inlet of the fuel cell, a reaction air supply flow path that connects the reaction air supply unit to the reaction air inlet of the fuel cell, a reaction air discharge flow path that connects the reaction air outlet of the fuel cell to the outside of the air-cooled fuel cell system, a housing unit, a temperature acquisition unit that acquires the temperature of the internal air discharged from the cooling air outlet, and a control unit. The control unit controls the opening / closing and opening degree of the opening / closing unit based on the temperature measured by the temperature acquisition unit.

Description

Technical Field

[0001] The present disclosure relates to an air-cooled fuel cell system. Background Art

[0002] A fuel cell (FC) is a power generation device composed of a single cell (hereinafter, there are cases where it is described as a unit) or a fuel cell stack formed by stacking a plurality of single cells (hereinafter, there are cases where it is only described as a stack), and extracts electrical energy through an electrochemical reaction between a fuel gas such as hydrogen and an oxidant gas such as oxygen. In addition, in practice, the fuel gas and oxidant gas supplied to the fuel cell are mostly mixtures with gases that do not contribute to oxidation and reduction. In particular, the oxidant gas is often air containing oxygen.

[0003] In addition, hereinafter, there are also cases where the fuel gas and the oxidant gas are not particularly distinguished and are simply referred to as "reaction gas" or "gas". In addition, there are cases where both a single cell and a fuel cell stack formed by stacking single cells are called fuel cells.

[0004] Regarding fuel cells used in fuel cell vehicles (hereinafter, there are cases where it is described as a vehicle), various technologies have been proposed.

[0005] For example, Patent Document 1 discloses a fuel cell stack assembly that includes a stack of fuel cells, each fuel cell having a cooling air passage and having an inlet / outlet ventilation opening disposed on the ventilation surface of the stack.

[0006] Patent Document 2 discloses a fuel cell system that suppresses a voltage drop as much as possible and prevents blockage of a flow path caused by condensed water.

[0007] Patent Document 3 discloses a boiler automatic number control method including a blowing operation.

[0008] Patent Document 4 discloses an operation method for an in-vehicle fuel cell stack that can rapidly raise the temperature of an air-cooled fuel cell to an appropriate power generation reaction temperature.

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-520500

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2001-015136

[0011] Patent Document 3: Japanese Patent Application Laid-Open No. 1990-021102

[0012] Patent Document 4: Japanese Patent Application Laid-Open No. 2005-216783

[0013] An air-cooled fuel cell distributes the external air introduced from the air inlet into reaction air and cooling air. On the other hand, similar to a water-cooled fuel cell, an air-cooled fuel cell needs to use the heat generated during power generation to circulate the cooling air in order to raise the temperature to a level suitable for power generation of the fuel cell.

[0014] In the above Patent Document 1, multiple cooling fans are required, so there are concerns such as an increase in weight, the need for a special fan when reversing the cooling fan, and the possibility of local overheating due to a decrease in flow rate when stopping some of the multiple fans. In addition, in the above Patent Document 1, since the reacted air is circulated in the fuel cell system, the liquid water and water vapor contained in the reacted air are also circulated at the same time, resulting in condensation and water accumulation in the system, thus there is a concern of causing a decrease in the performance of the fuel cell and deterioration of the fuel cell.

[0015] In addition, it is also possible to consider not adopting the circulation of the reacted air, but promoting the temperature rise of the fuel cell by reducing the flow rate of the cooling air as in Patent Document 4. However, since the thermal conductivity of air as a refrigerant is low, there is a possibility of local overheating. Summary of the Invention

[0016] The present disclosure is completed in view of the above actual situation, and its main object is to provide an air-cooled fuel cell system capable of efficiently preheating a fuel cell.

[0017] The air-cooled fuel cell system of the present disclosure is characterized in that the air-cooled fuel cell system includes: a fuel cell; a reaction air supply unit that supplies reaction air to the reaction air inlet of the fuel cell; a reaction air supply flow path that connects the reaction air supply unit to the reaction air inlet of the fuel cell; a reaction air discharge flow path that connects the reaction air outlet of the fuel cell to the outside of the air-cooled fuel cell system; a housing unit; a temperature acquisition unit that acquires the temperature of the internal air discharged from the cooling air outlet; and a control unit. The fuel cell has a structure in which the reaction air manifold and the cooling air manifold are independent. The housing unit houses the fuel cell, the reaction air supply unit, the reaction air supply flow path, the reaction air discharge flow path, and the temperature acquisition unit. The housing unit has a cooling air circulation flow path that connects the cooling air outlet of the fuel cell to the cooling air inlet of the fuel cell. The cooling air circulation flow path has a cooling air driving unit that is disposed at a position downstream of the cooling air outlet of the fuel cell and supplies cooling air to the cooling air inlet of the fuel cell. The housing unit has an air inlet and an air outlet. Pressure loss bodies are respectively disposed at the air inlet and the inlet of the reaction air supply flow path. The air outlet has an opening / closing unit. The control unit controls the opening / closing and the opening degree of the opening / closing unit based on the temperature measured by the temperature acquisition unit.

[0018] It may also be configured that, based on the air-cooled fuel cell system of the present disclosure, when it is determined that the internal air temperature measured by the temperature acquisition unit is lower than a specified first temperature threshold, the control unit makes the opening / closing unit lower than a specified opening degree to circulate the cooling air in the housing unit. When it is determined that the internal air temperature measured by the temperature acquisition unit is equal to or higher than the specified first temperature threshold and lower than a second temperature threshold, the control unit makes the opening / closing unit have a specified opening degree to circulate a part of the cooling air in the housing unit. When it is determined that the internal air temperature measured by the temperature acquisition unit is equal to or higher than the specified second temperature threshold, the control unit makes the opening / closing unit larger than the specified opening degree to discharge the cooling air to the outside of the housing unit.

[0019] It can also be configured as follows: Based on the air-cooled fuel cell system of the present disclosure, an external air temperature sensor is provided. When it is determined that the external air temperature is lower than a specified first temperature threshold, the control unit makes the opening and closing unit lower than a specified opening degree to circulate the cooling air in the accommodation part. When it is determined that the external air temperature is equal to or higher than the specified first temperature threshold and lower than the second temperature threshold, the control unit makes the opening and closing unit at a specified opening degree to circulate a part of the cooling air in the accommodation part. When it is determined that the external air temperature is equal to or higher than the specified second temperature threshold, the control unit makes the opening and closing unit greater than the specified opening degree to discharge the cooling air to the outside of the accommodation part.

[0020] According to the air-cooled fuel cell system of the present disclosure, the fuel cell can be preheated efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram showing an example of the air-cooled fuel cell system of the present disclosure and a diagram showing an example of the one-shot mode.

[0022] Figure 2 It is a schematic structural diagram showing another example of the air-cooled fuel cell system of the present disclosure and a diagram showing an example of the circulation mode.

[0023] Figure 3 It is a schematic structural diagram showing another example of the air-cooled fuel cell system of the present disclosure and a diagram showing an example of the intermediate mode.

[0024] Figure 4 It is a schematic structural diagram showing another example of the air-cooled fuel cell system of the present disclosure and a diagram showing another example of the circulation mode.

[0025] Figure 5 It is a flowchart showing an example of the control of the air-cooled fuel cell system of the present disclosure.

[0026] REFERENCE NUMERAL DESCRIPTION

[0027] 10... fuel cell; 20... air system; 21... air inlet; 22... reaction air inlet; 23... cooling air inlet; 30... oxidant gas system; 31... filter; 32... reaction air supply part; 33... reaction air supply flow path; 34... reaction air discharge flow path; 35... first valve; 36... second valve; 40... cooling system; 41... cooling air circulation flow path; 42... opening and closing part; 43... cooling air driving part; 60... control unit; 70... converter; 100... accommodation part; T1... external air temperature sensor; T2... temperature acquisition part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The air-cooled fuel cell system of the present disclosure is characterized in that the air-cooled fuel cell system includes: a fuel cell; a reaction air supply unit that supplies reaction air to the reaction air inlet of the fuel cell; a reaction air supply flow path that connects the reaction air supply unit to the reaction air inlet of the fuel cell; a reaction air discharge flow path that connects the reaction air outlet of the fuel cell to the outside of the air-cooled fuel cell system; a housing unit; a temperature acquisition unit that acquires the temperature of the internal air discharged from the cooling air outlet; and a control unit. The fuel cell has a structure in which the reaction air manifold and the cooling air manifold are independent. The housing unit houses the fuel cell, the reaction air supply unit, the reaction air supply flow path, the reaction air discharge flow path, and the temperature acquisition unit. The housing unit has a cooling air circulation flow path that connects the cooling air outlet of the fuel cell to the cooling air inlet of the fuel cell. The cooling air circulation flow path has a cooling air driving unit that is disposed at a position downstream of the cooling air outlet of the fuel cell and supplies cooling air to the cooling air inlet of the fuel cell. The housing unit has an air inlet and an air outlet. Pressure loss bodies are respectively disposed at the air inlet and the inlet of the reaction air supply flow path. The air outlet has an opening / closing unit. The control unit controls the opening / closing and the opening degree of the opening / closing unit based on the temperature measured by the temperature acquisition unit.

[0029] The air-cooled fuel cell system of the present disclosure has a structure that can prevent condensation and the like and can warm the fuel cell and auxiliary components as a whole by circulating cooling air inside the housing as the housing unit. The housing as the housing unit is provided with louvers for circulation ratio adjustment. In addition, when having the same structure in a water-cooled fuel cell system, since water as the refrigerant has conductivity, it causes a short circuit inside the fuel cell system, so it is difficult to install.

[0030] By circulating the cooling air, the overall temperature inside the housing of the air-cooled fuel cell system can be raised, and the periphery of the fuel cell, auxiliary components, etc. can also be heated. And according to the present disclosure, the risk of freezing and blocking of auxiliary components, pipes (flow paths), etc. below the freezing point can be reduced.

[0031] In addition, by not circulating the reaction air containing liquid water and water vapor after the reaction, the generation of condensation, water accumulation, oxygen concentration reduction, etc. can be suppressed. And according to the present disclosure, since it is not necessary to reduce the flow rate of the cooling air, the risk of short circuit, corrosion, etc. of the internal electronic circuit, cell, etc. caused by the generation of condensation, water accumulation, etc. can be reduced.

[0032] In addition, it is possible to warm up the fuel cell while making the temperature inside the fuel cell relatively uniform without reducing the flow rate of the cooling air. Therefore, it is possible to reduce the occurrence of local overheating caused by fluctuations in the flow rate of the cooling air due to water blockage in the refrigerant flow path, and it is possible to reduce the risk of deterioration of the power generation performance of the fuel cell, such as a decrease in power generation performance caused by local water accumulation due to an increase in the temperature difference within the cell surface, etc., so that the power generation performance of the fuel cell is stable.

[0033] The fuel cell system of the present disclosure is an air-cooled fuel cell system.

[0034] The air-cooled fuel cell system uses air as a refrigerant. In the present disclosure, there are cases where the air used as a refrigerant is referred to as cooling air. In the present disclosure, there are cases where the air used as an oxidant gas is referred to as reaction air.

[0035] The air-cooled fuel cell system includes a fuel cell, a reaction air supply unit, a reaction air supply flow path, a reaction air discharge flow path, a housing unit, a temperature acquisition unit, a control unit, etc.

[0036] The fuel cell generally has a single cell.

[0037] The fuel cell may have only one single cell, or may be a fuel cell stack formed by laminating a plurality of single cells.

[0038] The number of stacked single cells is not particularly limited. For example, it may be 2 to several hundred, may be 20 to 600, or may be 40 to 200.

[0039] The fuel cell stack may also include end plates, current collector plates, pressure plates, etc. at both ends in the stacking direction of the single cells.

[0040] The single cell of the fuel cell may also have a membrane electrode gas diffusion layer assembly (MEGA). The single cell of the fuel cell may also have a first separator and a second separator that sandwich the membrane electrode gas diffusion layer assembly.

[0041] The membrane electrode gas diffusion layer assembly sequentially has a first gas diffusion layer, a first catalyst layer, an electrolyte membrane, a second catalyst layer, and a second gas diffusion layer.

[0042] Specifically, the membrane electrode gas diffusion layer assembly sequentially has an anode-side gas diffusion layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, and a cathode-side gas diffusion layer.

[0043] One of the first catalyst layer and the second catalyst layer is a cathode catalyst layer, and the other is an anode catalyst layer.

[0044] The cathode (oxidant electrode) includes a cathode catalyst layer and a cathode-side gas diffusion layer.

[0045] The anode (fuel electrode) includes an anode catalyst layer and a gas diffusion layer on the anode side.

[0046] The first catalyst layer and the second catalyst layer are collectively referred to as the catalyst layer. The cathode catalyst layer and the anode catalyst layer are collectively referred to as the catalyst layer.

[0047] One of the first gas diffusion layer and the second gas diffusion layer is the gas diffusion layer on the cathode side, and the other is the gas diffusion layer on the anode side.

[0048] When the first catalyst layer is the cathode catalyst layer, the first gas diffusion layer is the gas diffusion layer on the cathode side, and when the first catalyst layer is the anode catalyst layer, the first gas diffusion layer is the gas diffusion layer on the anode side.

[0049] When the second catalyst layer is the cathode catalyst layer, the second gas diffusion layer is the gas diffusion layer on the cathode side, and when the second catalyst layer is the anode catalyst layer, the second gas diffusion layer is the gas diffusion layer on the anode side.

[0050] The first gas diffusion layer and the second gas diffusion layer are collectively referred to as the gas diffusion layer or the diffusion layer. The gas diffusion layer on the cathode side and the gas diffusion layer on the anode side are collectively referred to as the gas diffusion layer or the diffusion layer.

[0051] The gas diffusion layer can also be a conductive member having air permeability, etc.

[0052] Examples of the conductive member include carbon porous bodies such as carbon cloth and carbon paper, and metal porous bodies such as metal mesh and foamed metal.

[0053] The fuel cell may also have a microporous layer (MPL) between the catalyst layer and the gas diffusion layer. The microporous layer may also contain a mixture of a hydrophobic resin such as PTFE and a conductive material such as carbon black.

[0054] The electrolyte membrane can also be a solid polymer electrolyte membrane. Examples of the solid polymer electrolyte membrane include fluorine-based electrolyte membranes such as thin films containing perfluorosulfonic acid with water, and hydrocarbon-based electrolyte membranes. As the electrolyte membrane, for example, a perfluorosulfonic acid membrane (manufactured by DuPont) can also be used.

[0055] One of the first separator and the second separator is the separator on the cathode side, and the other is the separator on the anode side.

[0056] When the first catalyst layer is the cathode catalyst layer, the first separator is the separator on the cathode side, and when the first catalyst layer is the anode catalyst layer, the first separator is the separator on the anode side.

[0057] When the second catalyst layer is the cathode catalyst layer, the second separator is the cathode-side separator, and when the second catalyst layer is the anode catalyst layer, the second separator is the anode-side separator.

[0058] The first separator and the second separator are collectively referred to as separators. The anode-side separator and the cathode-side separator are collectively referred to as separators.

[0059] The membrane electrode gas diffusion layer assembly is clamped by the first separator and the second separator.

[0060] The separator may also have supply holes and discharge holes for allowing fluids such as reaction gases and refrigerants to flow in the stacking direction of the single cell. As the refrigerant, in the case of a gas, air for cooling or the like can be used.

[0061] Examples of the supply holes include a fuel gas supply hole, an oxidant gas supply hole, and a refrigerant supply hole.

[0062] Examples of the discharge holes include a fuel gas discharge hole, an oxidant gas discharge hole, and a refrigerant discharge hole.

[0063] The separator may have one or more fuel gas supply holes, may have one or more oxidant gas supply holes, may have one or more refrigerant supply holes as needed, may have one or more fuel gas discharge holes, may have one or more oxidant gas discharge holes, and may also have one or more refrigerant discharge holes as needed.

[0064] The separator may also have a reaction gas flow path on the surface in contact with the gas diffusion layer. In addition, the separator may have a refrigerant flow path on the surface opposite to the surface in contact with the gas diffusion layer for keeping the temperature of the fuel cell constant.

[0065] When the separator is the anode-side separator, it may have one or more fuel gas supply holes, may have one or more oxidant gas supply holes, may have one or more refrigerant supply holes as needed, may have one or more fuel gas discharge holes, may have one or more oxidant gas discharge holes, and may also have one or more refrigerant discharge holes as needed. The anode-side separator may have a fuel gas flow path on the surface in contact with the anode-side gas diffusion layer for allowing the fuel gas to flow from the fuel gas supply hole to the fuel gas discharge hole, and may also have a refrigerant flow path on the surface opposite to the surface in contact with the anode-side gas diffusion layer for allowing the refrigerant to flow from the refrigerant supply hole to the refrigerant discharge hole as needed.

[0066] In the case where the separator is a cathode-side separator, it may have more than one fuel gas supply hole, more than one oxidant gas supply hole, may have more than one refrigerant supply hole as needed, may have more than one fuel gas discharge hole, may have more than one oxidant gas discharge hole, and may also have more than one refrigerant discharge hole as needed. The cathode-side separator may have an oxidant gas flow path on the surface in contact with the cathode-side gas diffusion layer for the oxidant gas to flow from the oxidant gas supply hole to the oxidant gas discharge hole, and may also have a refrigerant flow path on the surface opposite to the surface in contact with the cathode-side gas diffusion layer for the refrigerant to flow from the refrigerant supply hole to the refrigerant discharge hole as needed.

[0067] The separator may also be an airtight conductive component or the like. As the conductive component, for example, it may also be resin materials such as thermosetting resin, thermoplastic resin, resin fiber, etc., carbon composite materials formed by stamping a mixture containing carbon materials such as carbon powder and carbon fiber, carbon compressed into airtight dense carbon, and stamped metal (e.g., titanium, iron, aluminum, and SUS, etc.) plates. In addition, the separator may also have a current collecting function.

[0068] The shape of the separator may also be rectangular, horizontally long hexagon, horizontally long octagon, circular, oval, etc.

[0069] The fuel cell may also have manifolds such as an inlet manifold where each supply hole communicates and an outlet manifold where each discharge hole communicates.

[0070] Examples of the inlet manifold include an anode inlet manifold, a reaction air inlet manifold (cathode inlet manifold), and a cooling air inlet manifold.

[0071] Examples of the outlet manifold include an anode outlet manifold, a reaction air outlet manifold (cathode outlet manifold), and a cooling air outlet manifold.

[0072] In the present disclosure, the reaction air inlet manifold (cathode inlet manifold) and the reaction air outlet manifold (cathode outlet manifold) are collectively referred to as the reaction air manifold.

[0073] In the present disclosure, the cooling air inlet manifold and the cooling air outlet manifold are collectively referred to as the cooling air manifold.

[0074] The fuel cell has a structure in which the reaction air manifold and the cooling air manifold are independent.

[0075] In the present disclosure, the fuel gas and the oxidant gas are collectively referred to as the reaction gas. The reaction gas supplied to the anode is the fuel gas, and the reaction gas supplied to the cathode is the oxidant gas. The fuel gas is a gas mainly containing hydrogen and may also be hydrogen gas. The oxidant gas may also be oxygen, air, dry air, etc.

[0076] The fuel cell may also include a resin frame.

[0077] It may also be configured such that the resin frame is disposed on the outer periphery of the membrane electrode gas diffusion layer assembly and between the first separator and the second separator.

[0078] In addition, the resin frame may also be a component for preventing cross leakage and electrical short - circuit between the catalyst layers of the membrane electrode gas diffusion layer assembly.

[0079] The resin frame may also have a skeleton portion, an opening portion, a supply hole, and a discharge hole.

[0080] The skeleton portion is the main part of the resin frame connected to the membrane electrode gas diffusion layer assembly.

[0081] The opening portion is a holding area of the membrane electrode gas diffusion layer assembly and is a through - hole that penetrates a part of the skeleton portion for accommodating the membrane electrode gas diffusion layer assembly. The opening portion may be disposed in the resin frame at a position where the skeleton portion is disposed around (outer peripheral portion) the membrane electrode gas diffusion layer assembly, or may have an opening portion in the center of the resin frame.

[0082] The supply hole and the discharge hole allow reaction gases, refrigerants, etc. to flow in the stacking direction of the single cell. The supply hole of the resin frame may be aligned and disposed in a manner that communicates with the supply hole of the separator. The discharge hole of the resin frame may be aligned and disposed in a manner that communicates with the discharge hole of the separator.

[0083] The resin frame may also include a frame - shaped core layer and two frame - shaped shell layers provided on both sides of the core layer, namely, the first shell layer and the second shell layer.

[0084] The first shell layer and the second shell layer may also be provided in a frame shape on both sides of the core layer in the same manner as the core layer.

[0085] The core layer may be a structural component having gas tightness and insulation, and may also be formed of a material whose structure does not change even under the temperature conditions during hot pressing in the fuel cell manufacturing process. Specifically, the material of the core layer may be, for example, resins such as polyethylene, polypropylene, PC (polycarbonate), PPS (polyphenylene sulfide), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PA (polyamide), PI (polyimide), PS (polystyrene), PPE (polyphenylene ether), PEEK (polyetheretherketone), cycloolefin, PES (polyethersulfone), PPSU (polyphenylsulfone), LCP (liquid crystal polymer), epoxy resin, etc. The material of the core layer may also be rubber materials such as EPDM (ethylene - propylene - diene monomer rubber), fluorine - based rubber, and silicone rubber.

[0086] From the viewpoint of ensuring insulation, the thickness of the core layer can be 5 μm or more, or can be 30 μm or more. From the viewpoint of reducing the unit thickness, it can be 200 μm or less, or can be 150 μm or less.

[0087] The first shell layer and the second shell layer have a relatively high adhesiveness to other substances, soften under the temperature conditions during hot pressing, and have a lower viscosity and melting point than the core layer in order to bond the core layer to the anode-side separator and the cathode-side separator to ensure sealing. Specifically, the first shell layer and the second shell layer can be thermoplastic resins such as polyester-based and modified olefin-based resins, or can be thermosetting resins such as modified epoxy resins. The first shell layer and the second shell layer can also be the same type of resin as the adhesive layer.

[0088] The resin constituting the first shell layer and the resin constituting the second shell layer can be the same type of resin or different types of resins. By providing shell layers on both sides of the core layer, the adhesion between the resin frame and the two separators based on hot stamping becomes easier.

[0089] From the viewpoint of ensuring adhesiveness, the thickness of each of the first shell layer and the second shell layer can be 5 μm or more, or can be 20 μm or more. From the viewpoint of reducing the unit thickness, it can be 100 μm or less, or can be 40 μm or less.

[0090] In the resin frame, the first shell layer and the second shell layer can be provided only in the portions that are bonded to the anode-side separator and the cathode-side separator, respectively. The first shell layer provided on one surface of the core layer can also be bonded to the cathode-side separator. The second shell layer provided on the other surface of the core layer can also be bonded to the anode-side separator. Moreover, the resin frame can also be clamped by a pair of separators.

[0091] The fuel cell can also have a gasket between two adjacent single cells.

[0092] As the material of the gasket, ethylene propylene diene monomer (EPDM), silicone rubber, thermoplastic elastomer resin, etc. can also be used.

[0093] The fuel cell can also have a cooling plate between two adjacent single cells.

[0094] The cooling plate is a corrugated plate having a plurality of grooves that function as refrigerant flow paths.

[0095] As the cooling plate, a plate obtained by bending a metal plate such as aluminum into a corrugated shape can be used. The cooling plate can also be subjected to conductive treatment such as silver, nickel, carbon, etc. on the surface.

[0096] The grooves of the cooling plate can also be formed by bending processing.

[0097] The depth of the groove can also be, for example, 1.0 to 2.0 mm.

[0098] For bending processing, for example, concavo-convex forming can also be performed at intervals with a groove depth of 1.0 to 2.0 mm and a width of 1.0 to 2.0 mm.

[0099] The cooling plate only needs to be arranged between two adjacent single cells, and can also be arranged in at least a part of the area in the plane direction between two adjacent single cells.

[0100] The cooling plate can also be arranged in at least the area opposite to MEGA in the plane direction between two adjacent single cells.

[0101] The cooling plate can also be arranged in the area other than the area where the gasket is arranged between two adjacent single cells in the plane direction.

[0102] The cooling plate can also have a protruding part protruding from the outer shape of the single cell.

[0103] The shape of the cooling plate can also be rectangular, horizontally long hexagon, horizontally long octagon, circular, oval, etc.

[0104] The accommodating part accommodates a fuel cell, an air supply part for reaction, an air supply flow path for reaction, an air discharge flow path for reaction, and a temperature acquisition part. The accommodating part can also be, for example, a housing. The material of the accommodating part is not particularly limited, and can also be metal, resin, carbon-based material, etc.

[0105] The accommodating part is equipped with a cooling system for the fuel cell. The accommodating part has a cooling air circulation flow path as the cooling system for the fuel cell. The cooling air circulation flow path can also be an area inside the accommodating part where components such as fuel cells, oxidant gas systems, fuel gas systems, and auxiliary machines are not arranged. As auxiliary machines, an ECU, a converter, an air compressor, etc. can be cited.

[0106] The cooling air circulation flow path connects the cooling air outlet of the fuel cell to the cooling air inlet of the fuel cell. The cooling air inlet can also be a refrigerant supply hole, a cooling air inlet manifold, etc. The cooling air outlet can also be a refrigerant discharge hole, a cooling air outlet manifold, etc.

[0107] The cooling air circulation flow path has a cooling air driving part.

[0108] The cooling air driving part is arranged at a position downstream of the cooling air outlet of the fuel cell and supplies cooling air to the cooling air inlet of the fuel cell.

[0109] The air driving unit for cooling is electrically connected to the control unit. The air driving unit for cooling is driven according to a control signal from the control unit. The air driving unit for cooling is controlled by the control unit to control the flow rate of the cooling air supplied from the air driving unit for cooling to the fuel cell. Thereby, the temperature of the fuel cell can also be controlled.

[0110] Examples of the air driving unit for cooling can include an air pump, an air compressor, a blower, an air fan, etc.

[0111] By providing the air driving unit for cooling on the outlet side of the cooling air of the fuel cell, the cooling system can make the pressure in the cooling air manifold of the fuel cell below atmospheric pressure.

[0112] The cooling system has an atmospheric connection structure without a valve. By making the cooling air at a pressure equal to the external air pressure (for example, -0.01 to -0.3 kPaG), it is possible to prevent differential pressure stress on the structure of the fuel cell and use inexpensive and lightweight housing components.

[0113] The accommodating part has an air inlet and an air outlet.

[0114] The air inlet introduces air from the outside of the air-cooled fuel cell system.

[0115] The air outlet exhausts air to the outside of the air-cooled fuel cell system.

[0116] The air outlet has an opening / closing part.

[0117] Examples of the opening / closing part can include a movable vent hole, a movable baffle, etc.

[0118] By having the opening / closing part, it is possible to select and control the "circulation mode" and "once-through mode" of the cooling air by opening and closing the opening / closing part.

[0119] The opening / closing part is electrically connected to the control unit. The opening and closing and the opening degree of the opening / closing part are controlled according to a control signal from the control unit. Thereby, the circulation flow rate and the exhaust flow rate of the cooling air can also be controlled.

[0120] Pressure loss elements are respectively arranged at the air inlet and the inlet of the reaction air supply flow path. Examples of the pressure loss element can include a filter, etc. By providing the pressure loss element at the air inlet, the heated air can be kept inside the accommodating part. In addition, by providing the pressure loss element at the air inlet, the efficiency of the air circulation inside the accommodating part is improved. By providing the pressure loss element at the inlet of the reaction air supply flow path, it is possible to suppress impurities from mixing into the oxidant gas system.

[0121] The accommodation part may also be provided with an air distribution part. The air distribution part distributes the air introduced from the air inlet into reaction air and cooling air before introducing it into the fuel cell. In addition, in the case of having a reaction air inlet for introducing reaction air from the outside and a cooling air inlet for introducing cooling air from the outside as the air inlet, an air distribution part is not necessarily required.

[0122] The distribution ratio of the reaction air and the cooling air for which the air distribution part distributes air may also be 1:20 to 1:50 by flow rate ratio.

[0123] The fuel cell system is provided with an oxidant gas system (reaction air system).

[0124] The oxidant gas system may also be provided with a reaction air supply part, a reaction air supply flow path, a reaction air discharge flow path, a reaction air bypass flow path, a bypass valve, a reaction air flow sensor, etc. Specifically, the reaction air supply flow path, the reaction air discharge flow path, and the reaction air bypass flow path may also be pipes.

[0125] The reaction air supply part supplies reaction air to the fuel cell. Specifically, the reaction air supply part supplies reaction air to the cathode of the fuel cell.

[0126] The enclosed volume of the oxidant gas system may also be 5 times or less of the enclosed volume of the fuel gas system.

[0127] The reaction air supply part supplies reaction air to the reaction air inlet of the fuel cell.

[0128] Examples of the reaction air supply part include an air pump, an air compressor, a blower, an air fan, etc.

[0129] The oxidant gas system is provided with a reaction air supply part independent before introducing the reaction air into the fuel cell. By independently providing a cooling air drive part and a reaction air supply part in each of the cooling system and the oxidant gas system, the flow rates of the cooling air and the reaction air can be independently controlled, the drainage control and the humidity control can be performed with high precision, and the power generation performance of the fuel cell can be improved.

[0130] The reaction air supply part is electrically connected to the control part. The reaction air supply part is driven according to a control signal from the control part. The reaction air supply part may also be controlled by the control part to control at least one selected from the group consisting of the flow rate and the pressure of the reaction air supplied from the reaction air supply part to the cathode.

[0131] The reaction air supply flow path connects the reaction air supply part and the reaction air inlet of the fuel cell.

[0132] The reaction air supply passage enables the supply of reaction air from the reaction air supply section to the cathode of the fuel cell. The reaction air inlet may also be an oxidant gas supply hole, a cathode inlet manifold, etc. The reaction air supply passage may also branch from the air distribution section. The reaction air supply passage may also branch from the cooling air circulation passage.

[0133] The reaction air supply passage may have a first valve in a region downstream of the reaction air supply section and upstream of the reaction air inlet of the fuel cell.

[0134] The first valve may be directly disposed at the reaction air inlet of the fuel cell.

[0135] The first valve may be disposed upstream of the reaction air supply section.

[0136] The first valve is electrically connected to the control section, and by opening the first valve through the control section, reaction air is supplied from the reaction air supply passage to the reaction air inlet of the fuel cell.

[0137] A pressure loss body is provided at the inlet of the reaction air supply passage. A pressure loss body may also be provided upstream of the reaction air supply section of the reaction air supply passage. Examples of the pressure loss body include a filter. The pressure loss body provided in the reaction air supply passage may use a filter with a higher pressure loss and finer pores than the pressure loss body provided at the air inlet. If the entire air introduction system is cleaned, the energy loss of the fuel cell increases, but by cleaning only the oxidant gas system, the energy loss of the fuel cell can be suppressed. In addition, since a finer filter is used, contamination of the cooling air can be reduced, and the durability of the fuel cell can be improved.

[0138] The reaction air discharge passage connects the reaction air outlet of the fuel cell to the outside of the air-cooled fuel cell system. The reaction air discharge passage enables the discharge of the reaction air discharged from the cathode of the fuel cell to the outside of the air-cooled fuel cell system. The reaction air outlet may also be an oxidant gas discharge hole, a cathode outlet manifold, etc.

[0139] The reaction air discharge passage may have a second valve downstream of the reaction air outlet of the fuel cell. The second valve may be a seal valve or an oxidant gas pressure adjustment valve.

[0140] The second valve is electrically connected to the control section, and by opening the second valve through the control section, the reaction air is discharged from the reaction air discharge passage to the outside. In addition, the pressure of the reaction air supplied to the cathode (cathode pressure) may be adjusted by adjusting the opening degree of the second valve.

[0141] The reaction air bypass flow path branches from the reaction air supply flow path, bypasses the fuel cell, and connects the branch portion of the reaction air supply flow path to the confluence portion of the reaction air discharge flow path.

[0142] A bypass valve is arranged in the reaction air bypass flow path.

[0143] The bypass valve is electrically connected to the control unit. By opening the bypass valve through the control unit, when the supply of reaction air to the fuel cell is not required, the reaction air can be discharged to the outside from the reaction air discharge flow path while bypassing the fuel cell.

[0144] A reaction air flow sensor may also be arranged in the reaction air supply flow path.

[0145] The reaction air flow sensor detects the flow rate of the reaction air in the oxidant gas system. The reaction air flow sensor is electrically connected to the control unit. The control unit may also infer the rotational speed of the air compressor based on the flow rate of the reaction air detected by the reaction air flow sensor. The reaction air flow sensor may also be arranged at a position upstream of the reaction air supply portion in the reaction air supply flow path.

[0146] The reaction air flow sensor can adopt a conventionally well-known flow meter or the like.

[0147] For the oxidant gas system, through the reaction air supply portion and the second valve, the pressure in the reaction air manifold of the fuel cell can be made above atmospheric pressure (for example, 5 - 15 kPaG).

[0148] Through the second valve of the oxidant gas system, the pressure of the reaction air can be increased. Therefore, the performance of the fuel cell can be improved by increasing the oxygen partial pressure and preventing the fuel cell from drying.

[0149] Without separating the oxidant gas system and the cooling system, it is necessary to increase the pressure of the cooling air by about 30 times the flow rate of the reaction air, and the energy loss becomes more than 30 times.

[0150] The fuel cell system is equipped with a fuel gas system.

[0151] The fuel gas system supplies fuel gas to the fuel cell.

[0152] The fuel gas system is equipped with a fuel gas supply portion.

[0153] The fuel gas supply portion supplies fuel gas to the anode of the fuel cell.

[0154] As the fuel gas supply portion, for example, a fuel tank or the like can be cited. Specifically, a liquid hydrogen tank, a compressed hydrogen tank, etc. can be cited.

[0155] The fuel gas supply unit is electrically connected to the control unit. The fuel gas supply unit may also be configured to control the opening and closing of the main shut-off valve of the fuel gas supply unit according to a control signal from the control unit, thereby controlling the opening and closing of the supply of fuel gas to the fuel cell.

[0156] The fuel gas system includes a fuel gas supply flow path. Specifically, the fuel gas supply flow path may also be a pipe.

[0157] The fuel gas supply flow path connects the fuel gas supply unit to the fuel gas inlet of the fuel cell. The fuel gas supply flow path enables the supply of fuel gas to the anode of the fuel cell. The fuel gas inlet may also be a fuel gas supply hole, an anode inlet manifold, etc.

[0158] The fuel gas supply flow path has a third valve upstream of the fuel gas inlet of the fuel cell.

[0159] The third valve may also be directly disposed at the fuel gas inlet of the fuel cell.

[0160] The third valve may also be disposed upstream of the ejector.

[0161] The third valve is electrically connected to the control unit, and by opening the third valve through the control unit, the fuel gas is supplied from the fuel gas supply flow path to the fuel gas inlet of the fuel cell.

[0162] An ejector may also be disposed in the fuel gas supply flow path.

[0163] The ejector may be disposed, for example, at the confluence of the fuel gas supply flow path and the recycle flow path. The ejector supplies a mixed gas including fuel gas and recycle gas to the anode of the fuel cell. As the ejector, a conventionally known ejector can be adopted.

[0164] A pressure regulating valve and a medium-pressure hydrogen sensor may also be disposed in the region between the fuel gas supply unit and the ejector of the fuel gas supply flow path.

[0165] The pressure regulating valve regulates the pressure of the fuel gas supplied from the fuel gas supply unit to the ejector.

[0166] It may also be configured such that the pressure regulating valve is electrically connected to the control unit, and the opening and closing and the opening degree of the pressure regulating valve are controlled through the control unit, thereby adjusting the pressure of the fuel gas supplied to the ejector.

[0167] It may also be configured such that the medium-pressure hydrogen sensor is electrically connected to the control unit, the control unit detects the pressure of the fuel gas measured by the medium-pressure hydrogen sensor, and controls the opening and closing and the opening degree of the pressure regulating valve according to the detected pressure, thereby adjusting the pressure of the fuel gas supplied to the ejector.

[0168] The fuel gas system has a fuel exhaust gas discharge flow path. Specifically, the fuel exhaust gas discharge flow path can also be a pipe.

[0169] The fuel exhaust gas discharge flow path connects the fuel gas outlet of the fuel cell to the outside of the fuel cell system.

[0170] In the fuel exhaust gas discharge flow path, a gas-liquid separator can also be arranged in the area between the fuel gas outlet and the outside of the fuel cell system.

[0171] The fuel exhaust gas discharge flow path can also branch from the circulation flow path via the gas-liquid separator.

[0172] The fuel exhaust gas discharge flow path discharges the fuel exhaust gas discharged from the fuel gas outlet of the fuel cell to the outside of the fuel cell system. The fuel gas outlet can also be a fuel gas discharge hole, an anode outlet manifold, etc.

[0173] The fuel exhaust gas discharge flow path has a fourth valve (fuel exhaust gas discharge valve, exhaust and drainage valve) downstream of the fuel gas outlet of the fuel cell.

[0174] The fourth valve can also be directly arranged at the fuel gas outlet of the fuel cell.

[0175] The fourth valve can also be arranged at a position downstream of the gas-liquid separator in the fuel exhaust gas discharge flow path.

[0176] The fourth valve can discharge fuel exhaust gas, moisture, etc. to the outside (outside the system).

[0177] In addition, the outside can be the outside of the fuel cell system or the outside of the vehicle.

[0178] It can also be configured that the fourth valve is electrically connected to the control unit, and the opening and closing of the fourth valve are controlled by the control unit, thereby adjusting the discharge flow rate of fuel exhaust gas to the outside and the drainage flow rate of moisture (liquid water). In addition, the fuel gas pressure (anode pressure) supplied to the anode of the fuel cell can also be adjusted by adjusting the opening degree of the fourth valve.

[0179] The fuel exhaust gas can also contain fuel gas that remains unreacted in the anode and directly passes through, and moisture such as generated water generated at the cathode reaching the anode. There are cases where the fuel exhaust gas contains corrosive substances generated in the catalyst layer, electrolyte membrane, etc., and oxidant gas that can be supplied to the anode during scavenging.

[0180] The fuel gas system can also have a circulation flow path. Specifically, the circulation flow path can also be a pipe.

[0181] The circulation flow path can also connect the fuel gas outlet of the fuel cell to the ejector.

[0182] It can also be configured such that the circulation flow path branches from the fuel exhaust gas discharge flow path and is connected to an ejector disposed in the fuel gas supply flow path, and thus merges with the fuel gas supply flow path.

[0183] It can also be configured such that the circulation flow path branches from the fuel exhaust gas discharge flow path via a gas-liquid separator and is connected to an ejector disposed in the fuel gas supply flow path, and thus merges with the fuel gas supply flow path.

[0184] The circulation flow path can recover fuel exhaust gas, which is fuel gas discharged from the fuel gas outlet of the fuel cell, and supply it as recycled gas to the fuel cell.

[0185] A gas circulation pump can also be disposed in the circulation flow path. The gas circulation pump circulates the fuel exhaust gas as recycled gas. It can also be configured such that the gas circulation pump is electrically connected to the control unit, and the control unit controls the on / off and rotational speed, etc. of the drive of the gas circulation pump, thereby adjusting the flow rate of the recycled gas.

[0186] A gas-liquid separator (anode gas-liquid separator) can also be disposed in the circulation flow path.

[0187] The gas-liquid separator is disposed at the branch point of the fuel exhaust gas discharge flow path and the circulation flow path.

[0188] Therefore, the flow path from the fuel gas outlet to the gas-liquid separator can be the fuel exhaust gas discharge flow path or the circulation flow path.

[0189] The gas-liquid separator is disposed at a position upstream of the fourth valve in the fuel exhaust gas discharge flow path.

[0190] The gas-liquid separator separates fuel exhaust gas, which is fuel gas discharged from the fuel gas outlet, from moisture (liquid water). Thereby, the fuel exhaust gas can be returned as recycled gas to the circulation flow path, or the exhaust drain valve of the fuel exhaust gas discharge flow path can be opened to discharge unnecessary gas and moisture, etc. to the outside. In addition, through the gas-liquid separator, the flow of excess moisture into the circulation flow path can be suppressed, and thus the generation of freezing of the circulation pump, etc. caused by this moisture can be suppressed.

[0191] The temperature acquisition unit acquires the temperature of the air inside the housing discharged from the cooling air outlet of the fuel cell.

[0192] The temperature acquisition unit is electrically connected to the control unit, and the control unit detects the temperature of the air inside the housing measured by the temperature acquisition unit.

[0193] The temperature acquisition unit can use conventionally known temperature sensors, thermometers, etc.

[0194] The fuel cell system can also include a secondary battery.

[0195] A secondary battery (storage battery) only needs to be able to charge and discharge. For example, well-known secondary batteries in the past such as nickel-metal hydride secondary batteries and lithium-ion secondary batteries can be cited. In addition, the secondary battery may also include a power storage element such as an electric double layer capacitor. The secondary battery may also have a structure in which a plurality are connected in series. The secondary battery supplies power to an electric motor, an air compressor, etc. The secondary battery can also be charged from a power source outside the vehicle, for example. The secondary battery can also be charged by the output of a fuel cell. The charge and discharge of the secondary battery can be controlled by a control unit.

[0196] Physically, the control unit has, for example, an arithmetic processing device such as a CPU (central processing unit), a ROM (read-only memory) that stores a control program, control data, etc. processed by the CPU, and a RAM (random access memory) that is mainly used as various working areas for control processing, etc. storage devices, as well as an input / output interface. In addition, the control unit can also be a control device such as an electronic control unit (ECU: Electronic Control Unit), for example.

[0197] The control unit can also be electrically connected to an ignition switch, and the above ignition switch can also be mounted on a vehicle. Even if the ignition switch is turned off, the control unit can operate through an external power source.

[0198] The control unit monitors the temperature measured by the temperature acquisition unit. The control unit can also monitor the temperature measured by the temperature acquisition unit during the operation of the fuel cell.

[0199] The control unit controls the opening and closing and the opening degree of the opening / closing unit based on the temperature measured by the temperature acquisition unit.

[0200] Based on the temperature measured by the temperature acquisition unit and the operating state of the fuel cell, it is determined whether it is necessary to warm up the fuel cell. When warming up the fuel cell, the opening / closing unit such as a shutter is closed, so that the cooling air circulates in the accommodation part, thereby enabling preheating operation.

[0201] Even during the normal operation of the fuel cell, by making the opening / closing unit such as a shutter in a semi-open state, it is possible to become a circulation mode of obtaining a part of the external air and become an "intermediate mode" of operating the fuel cell at a target temperature.

[0202] When it is determined that the internal air temperature measured by the temperature acquisition unit is lower than a specified first temperature threshold, the control unit can also make the opening / closing unit lower than a specified opening degree to circulate the cooling air in the accommodation part. The specified opening degree can also be, for example, that the opening degree of the opening / closing unit is 0% or more and less than 5%.

[0203] When it is determined that the internal air temperature measured by the temperature acquisition unit is equal to or higher than a specified first temperature threshold and lower than a second temperature threshold, the control unit may also set the opening / closing unit to a specified opening degree to circulate a part of the cooling air within the accommodation unit. The specified opening degree may be, for example, 5% or more and 90% or less of the opening degree of the opening / closing unit.

[0204] When it is determined that the internal air temperature measured by the temperature acquisition unit is equal to or higher than the specified second temperature threshold, the control unit may also set the opening / closing unit to a degree greater than the specified opening degree to discharge the cooling air to the outside of the accommodation unit. The specified opening degree may be, for example, more than 90% and 100% or less of the opening degree of the opening / closing unit.

[0205] For the control unit, in the case where the internal air temperature is lower than the appropriate temperature, the circulation mode may be executed; in the case where the internal air temperature is within the appropriate temperature range, the intermediate mode may be executed; and in the case where the internal air temperature is higher than the appropriate temperature range, the one-shot mode may also be executed.

[0206] The specified first temperature threshold and second temperature threshold may also be changed at any time according to the power generation state and performance of the fuel cell.

[0207] The first temperature threshold may be, for example, 0°C or higher, 10°C or higher, 20°C or higher, 30°C or higher, 40°C or higher, etc.

[0208] The second temperature threshold may be, for example, 80°C or lower, 70°C or lower, 60°C or lower, 50°C or lower, 40°C or lower, etc.

[0209] The air-cooled fuel cell system may also be provided with an external air temperature sensor.

[0210] The external air temperature sensor acquires the external air temperature.

[0211] The external air temperature sensor is electrically connected to the control unit, and the control unit detects the external air temperature measured by the external air temperature sensor.

[0212] As the external air temperature sensor, a conventionally known temperature sensor, thermometer, etc. may be used.

[0213] As long as the external air temperature sensor can measure the external air temperature, it may be arranged outside the accommodation unit or inside the accommodation unit.

[0214] When it is determined that the external air temperature is lower than the specified first temperature threshold, the control unit may also set the opening / closing unit to a degree smaller than the specified opening degree to circulate the cooling air within the accommodation unit. The specified opening degree may be, for example, 0% or more and less than 5% of the opening degree of the opening / closing unit.

[0215] When it is determined that the external air temperature is equal to or higher than a specified first temperature threshold and lower than a second temperature threshold, the control unit may also set the opening / closing unit to a specified opening degree to circulate a part of the cooling air within the accommodating unit. The specified opening degree may be, for example, 5% or more and 90% or less of the opening degree of the opening / closing unit.

[0216] When it is determined that the external air temperature is equal to or higher than the specified second temperature threshold, the control unit may also set the opening / closing unit to a degree greater than the specified opening degree to discharge the cooling air to the outside of the accommodating unit. The specified opening degree may be, for example, more than 90% and 100% or less of the opening degree of the opening / closing unit.

[0217] The specified first temperature threshold and second temperature threshold may also vary at any time according to the power generation state and performance of the fuel cell.

[0218] For the control unit, in the case where the external air temperature is lower than the reference value, the circulation mode may be executed; in the case where the external air temperature is within the range of the reference value, the intermediate mode may be executed; and in the case where the external air temperature is higher than the reference value, the one-shot mode may also be executed.

[0219] The first temperature threshold may be, for example, -20°C or lower, -10°C or lower, 0°C or lower, etc.

[0220] The second temperature threshold may be, for example, 10°C or higher, 20°C or higher, 30°C or higher, etc.

[0221] In the case where the optimal operating conditions of the fuel cell are an inlet temperature of the cooling air of 30°C and an outlet temperature of the cooling air of 60°C, the rotational speed of the fan, which is the cooling air driving unit, may also be set to a flow rate at which the temperature difference ΔT between the internal air temperature and the external air temperature is 30°C according to the calorific value of the operating point of the fuel cell.

[0222] It may also be configured such that when the external air temperature T1 is 30°C, the fuel cell is operated in a one-shot mode without circulating the cooling air.

[0223] It may also be configured such that when the external air temperature T1 is 0°C, the shutter, which is the opening / closing unit, is closed at the start of the fuel cell to start the operation of the fuel cell in the circulation mode.

[0224] It may also be configured such that the temperature within the accommodating unit rises slowly, and when the internal air temperature T2 changes from 0°C to 60°C, the shutter is set to half-open to enter the intermediate mode.

[0225] If the flow rate ratio of the air becomes external air: internal circulation = 1:1, the external air at 0°C and the circulating air at 60°C are mixed at 1:1, and the inlet temperature of the cooling air for the fuel cell becomes 30°C and the outlet temperature becomes 60°C, thereby enabling the target operating environment to be achieved.

[0226] In addition, when the flow rate of the cooling air is reduced to half without circulation, the cooling air outlet can reach 60°C, but the inlet side of the cooling air for the fuel cell becomes 0°C, the temperature difference within the cell surface becomes large, water accumulates in the colder parts, and the air flow rate fluctuates, etc., making the operation of the fuel cell prone to instability. From the perspective of improving the circulation efficiency, a part of the auxiliary equipment can also be isolated from the cooling system without heating up.

[0227] Figure 1 It is a schematic structural diagram showing an example of the air-cooled fuel cell system of the present disclosure and is a diagram showing an example of the one-shot mode. In addition, in Figure 1 the illustration of the fuel gas system, details of the auxiliary equipment, etc. are omitted.

[0228] Figure 1 The air-cooled fuel cell system shown has a housing part 100. The housing part 100 has a fuel cell 10, an air system 20, an oxidant gas system 30, a cooling system 40, a control part 60, an external air temperature sensor T1, and a temperature acquisition part T2.

[0229] The air system 20 includes the oxidant gas system 30 and the cooling system 40.

[0230] The housing part 100 has an air inlet 21 equipped with a filter.

[0231] The air obtained through the air inlet 21 is distributed to the oxidant gas system 30 and the cooling system 40.

[0232] The oxidant gas system 30 has a filter 31, a reaction air supply part 32, a reaction air supply flow path 33, and a reaction air discharge flow path 34.

[0233] In the reaction air supply flow path 33, the filter 31 and the reaction air supply part 32 are arranged along the air flow direction.

[0234] The cooling system 40 has a cooling air circulation flow path 41, an opening / closing part 42, and a cooling air driving part 43. The opening / closing part 42 is arranged at the exhaust port of the housing part 100.

[0235] The external air temperature sensor T1 acquires the external air temperature, and a control part (not shown) detects the external air temperature acquired by the external air temperature sensor T1.

[0236] The temperature acquisition part T2 acquires the internal air temperature discharged from the cooling air outlet of the fuel cell 10, and a control part (not shown) detects the temperature acquired by the temperature acquisition part T2.

[0237] In the one-shot mode, the opening / closing part 42 is fully opened to exhaust the cooling air to the outside.

[0238] Figure 2 FIG. is a schematic configuration diagram showing another example of the air-cooled fuel cell system of the present disclosure, and is a diagram showing an example of the circulation mode. In Figure 2 For the same structure as Figure 1 the same reference numerals are assigned, and the description thereof is omitted.

[0239] In Figure 2 the circulation mode shown, the opening / closing part 42 is fully closed to circulate the cooling air inside the housing part 100.

[0240] Figure 3 FIG. is a schematic configuration diagram showing another example of the air-cooled fuel cell system of the present disclosure, and is a diagram showing an example of the intermediate mode. In Figure 3 For the same structure as Figure 1 the same reference numerals are assigned, and the description thereof is omitted.

[0241] In Figure 3 the intermediate mode shown, the opening / closing part 42 is semi-closed to circulate a part of the cooling air inside the housing part 100, and exhaust the remaining part to the outside.

[0242] Figure 4 FIG. is a schematic configuration diagram showing another example of the air-cooled fuel cell system of the present disclosure, and is a diagram showing another example of the circulation mode. In Figure 4 For the same structure as Figure 1 the same reference numerals are assigned, and the description thereof is omitted.

[0243] In Figure 4 the air-cooled fuel cell system of, the air system 20 has a reaction air inlet 22 for supplying air to the oxidant gas system 30 and a cooling air inlet 23 for supplying air to the cooling system 40. The reaction air inlet 22 and the cooling air inlet 23 each have a filter.

[0244] The oxidant gas system 30 and the cooling system 40 each obtain air from the atmosphere through the filter.

[0245] The oxidant gas system 30 has a filter 31, a reaction air supply part 32, a reaction air supply flow path 33, a reaction air discharge flow path 34, a first valve 35, and a second valve 36.

[0246] The filter 31, the reaction air supply part 32, and the first valve 35 are arranged along the air flow direction in the reaction air supply flow path 33.

[0247] The second valve 36 is arranged in the reaction air discharge flow path 34.

[0248] In Figure 4 In the air-cooled fuel cell system, auxiliary devices such as the reaction air supply section 32, the control section 60, and the converter 70 are isolated from the cooling air circulation flow path 41.

[0249] Figure 5 It is a flowchart showing an example of the control of the air-cooled fuel cell system of the present disclosure.

[0250] During the operation of the fuel cell, the control section monitors the temperature measured by the temperature acquisition section.

[0251] When it is determined that the internal air temperature measured by the temperature acquisition section is lower than the specified first temperature threshold, the control section executes the circulation mode.

[0252] When it is determined that the internal air temperature measured by the temperature acquisition section is equal to or higher than the specified first temperature threshold and lower than the second temperature threshold, the control section executes the intermediate mode.

[0253] When it is determined that the internal air temperature measured by the temperature acquisition section is equal to or higher than the specified second temperature threshold, the control section executes the one-shot mode.

Claims

1. An air-cooled fuel cell system, characterized in that, the air-cooled fuel cell system includes: a fuel cell; a reaction air supply unit that supplies reaction air to the reaction air inlet of the fuel cell; a reaction air supply flow path that connects the reaction air supply unit to the reaction air inlet of the fuel cell; a reaction air discharge flow path that connects the reaction air outlet of the fuel cell to the outside of the air-cooled fuel cell system; a housing portion; an external air temperature sensor; a temperature acquisition unit that acquires the internal air temperature discharged from the cooling air outlet; and a control unit, the fuel cell has a structure in which the reaction air manifold and the cooling air manifold are independent, the housing portion houses the fuel cell, the reaction air supply unit, the reaction air supply flow path, the reaction air discharge flow path, and the temperature acquisition unit, the housing portion has a cooling air circulation flow path that connects the cooling air outlet of the fuel cell to the cooling air inlet of the fuel cell, the cooling air circulation flow path has a cooling air driving unit that is disposed at a position downstream of the cooling air outlet of the fuel cell and supplies cooling air to the cooling air inlet of the fuel cell, the housing portion has an air inlet and an air outlet, filters are respectively disposed at the air inlet and the inlet of the reaction air supply flow path, the air outlet has an opening / closing portion, the control unit controls the opening / closing and the opening degree of the opening / closing portion based on the temperature measured by the temperature acquisition unit, when it is determined that the external air temperature is lower than a specified first temperature threshold, the control unit makes the opening degree of the opening / closing portion be 0% or more and less than 5%, so as to circulate the cooling air in the housing portion, when it is determined that the external air temperature is equal to or higher than the specified first temperature threshold and lower than a specified second temperature threshold, the control unit makes the opening degree of the opening / closing portion be 5% or more and 90% or less, so as to circulate a part of the cooling air in the housing portion, when it is determined that the external air temperature is equal to or higher than the specified second temperature threshold, the control unit makes the opening degree of the opening / closing portion be more than 90% and 100% or less, so as to discharge the cooling air to the outside of the housing portion.

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