Air-cooled fuel cell system

Abstract

The invention provides a fuel cell system capable of suppressing the occurrence of condensation and freezing of valves and piping. The fuel cell system is an air-cooled fuel cell system provided with a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell. The fuel cell has a reaction air flow path and a cooling air flow path each having a flow path structure in which the reaction air and the cooling air are independent, the hydrogen system has a circulation system for circulating the hydrogen supplied to the fuel cell, and the fuel cell system has a housing for accommodating the fuel cell. The housing has an upstream-side space and a downstream-side space in the direction of flow of the cooling air within the housing with respect to the fuel cell, and the circulation system of the hydrogen system is disposed in the downstream-side space.

Description

Technical Field

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

[0002] Various technologies have been proposed regarding fuel cells (FC) such as those disclosed in Patent Documents 1 to 4.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-185248

[0004] Patent Document 2: Japanese Patent Application Publication No. 2006-209994

[0005] Patent Document 3: Japanese Patent Application Publication No. 2022-185251

[0006] Patent Document 4: Japanese Patent Application Publication No. 2022-185247

[0007] In the prior art, the temperature management of the reaction air system and the hydrogen system is not considered. Due to the generation of condensation during the shutdown of the fuel cell system, when the ambient temperature of the fuel cell system is low, freezing may occur on the valves and piping. In addition, in order to suppress condensation, an additional structure for suppressing condensation is required, which inevitably increases the size of the fuel cell system. Summary of the invention

[0008] The present disclosure has been made in view of the above-mentioned actual situation, and a main object thereof is to provide an air-cooled fuel cell system capable of suppressing the occurrence of condensation and freezing of valves and piping.

[0009] In the first embodiment of the present disclosure, a fuel cell system is provided, which is an air-cooled fuel cell system, characterized in that the fuel cell system includes a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell, the fuel cell has a reaction air flow path and a cooling air flow path with independent flow path structures for the reaction air and the cooling air, the hydrogen system has a circulation system for circulating the hydrogen supplied to the fuel cell, the fuel cell system has a casing, the casing accommodates the fuel cell, the casing has an upstream space and a downstream space in the flow direction of the cooling air in the casing based on the fuel cell, and the circulation system of the hydrogen system is arranged in the downstream space.

[0010] In the second embodiment of the present disclosure, a fuel cell system is provided, which is an air-cooled fuel cell system, characterized in that the fuel cell system comprises a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell, the fuel cell having a reaction air flow path and a cooling air flow path with independent flow path structures for the reaction air and the cooling air, the hydrogen system having a hydrogen purge valve at an outlet of the hydrogen of the fuel cell, the fuel cell system having a casing for accommodating the fuel cell, the casing having an upstream space and a downstream space in a flow direction of the cooling air in the casing with the fuel cell as a reference, and the hydrogen purge valve of the hydrogen system is arranged in the downstream space.

[0011] In the third embodiment of the present disclosure, a fuel cell system is provided, which is an air-cooled fuel cell system, characterized in that the fuel cell system comprises a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell, the fuel cell having a reaction air flow path and a cooling air flow path with independent flow path structures for the reaction air and the cooling air, the reaction air system having an inlet side sealing valve at the inlet of the reaction air of the fuel cell and an outlet side sealing valve at the outlet of the reaction air of the fuel cell, the fuel cell system having a casing which accommodates the fuel cell, the casing having an upstream side space and a downstream side space in the flow direction of the cooling air in the casing with the fuel cell as a reference, and at least the outlet side sealing valve in the reaction air system is arranged in the downstream side space.

[0012] In the fourth embodiment of the present disclosure, it can also be constructed as follows: on the basis of the first embodiment, the above-mentioned hydrogen system has the above-mentioned circulation system, and has a hydrogen purge valve at the above-mentioned hydrogen outlet of the above-mentioned fuel cell, and the above-mentioned circulation system and the above-mentioned hydrogen purge valve of the above-mentioned hydrogen system are arranged in the above-mentioned downstream side space.

[0013] In the fifth embodiment of the present disclosure, it can also be constructed as follows: on the basis of the first embodiment, the hydrogen system has the circulation system, and has a hydrogen purge valve at the hydrogen outlet of the fuel cell, the reaction air system has an inlet side sealing valve at the reaction air inlet of the fuel cell, and has an outlet side sealing valve at the reaction air outlet of the fuel cell, and the circulation system of the hydrogen system, the hydrogen purge valve, and at least the outlet side sealing valve in the reaction air system are arranged in the downstream side space.

[0014] The fuel cell system of the present disclosure can suppress the occurrence of condensation and freezing of valves and pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an exploded perspective schematic diagram showing an example of a single cell of a fuel cell included in the fuel cell system of the present disclosure.

[0016] Figure 2 It is a perspective schematic diagram showing an example of a fuel cell stack included in the fuel cell system of the present disclosure.

[0017] Figure 3 (1) is a system configuration diagram showing an example of a fuel cell system of the present disclosure, Figure 3 (2) is a system configuration diagram showing an example of a conventional fuel cell system.

[0018] Figure 4 (1) is a system configuration diagram showing another example of the fuel cell system disclosed in the present invention. Figure 4 (2) is a system configuration diagram showing another example of a conventional fuel cell system.

[0019] Description of Reference Numerals

[0020] 1…battery cell; 2…cooling fin (cooling air flow path); 3…reaction air inlet; 4…reaction air outlet; 5…hydrogen inlet; 6…hydrogen outlet; 7…cooling air (cooling gas); 8…hydrogen; 9…reaction air; 10…fuel cell stack; 11…diaphragm; 12…MEA, resin frame; 13…collector plate; 14…pressurizing plate; 20…reaction air system; 21…reaction air intake port; 22…air blower; 23…inlet side sealing valve; 24…outlet side sealing valve; 30…cooling air system; 31…cooling fan; 32…intake port; 40…hydrogen system; 41…hydrogen tank; 42…hydrogen inlet valve; 43…gas-liquid separator; 44…hydrogen purge valve; 45…hydrogen pump; 50…housing; 51…partition wall; 52…upstream side space; 53…downstream side space. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present disclosure. In addition, matters required for the implementation of the present disclosure other than matters specifically mentioned in this specification (for example, the general structure and manufacturing process of the fuel cell system that does not characterize the present disclosure) can be understood as design matters for those skilled in the art based on the prior art in the art. The present disclosure can be implemented based on the contents disclosed in this specification and the technical common sense in the art.

[0022] In addition, the dimensional relationships (length, width, thickness, etc.) in the drawings do not reflect the actual dimensional relationships.

[0023] In the present disclosure, the gas supplied to the anode of the fuel cell is the fuel gas (anode gas), and the gas supplied to the cathode of the fuel cell is the oxidant gas (cathode gas). The fuel gas is a gas mainly containing hydrogen, and may also be hydrogen. The oxidant gas is a gas containing oxygen, and may also be oxygen, air, etc. In the present disclosure, the air serving as the oxidant gas is referred to as reaction air, and the air serving as the cooling gas is referred to as cooling air.

[0024] In the present disclosure, a fuel cell system is provided, which is an air-cooled fuel cell system, characterized in that the fuel cell system includes a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell, the fuel cell has a reaction air flow path and a cooling air flow path with independent flow path structures for the reaction air and the cooling air, the hydrogen system has a circulation system for circulating the hydrogen supplied to the fuel cell, the fuel cell system has a shell, the shell accommodates the fuel cell, the shell has an upstream side space and a downstream side space in the flow direction of the cooling air in the shell based on the fuel cell, and the circulation system of the hydrogen system is arranged in the downstream side space.

[0025] If a heater is provided to heat supply devices such as valves in order to prevent condensation and water blockage, the housing will be enlarged, the device cost will be increased, and the power consumption will increase. According to the present disclosure, by arranging supply devices such as valves in the downstream space of the housing of an air-cooled fuel cell system, the temperature of the cooling air in the downstream space of the housing is high, thereby suppressing condensation, water blockage, and subsequent freezing of these devices. For example, in order to suppress condensation and water blockage in a hydrogen system, the piping after gas-liquid separation and the hydrogen pump of the circulation system are arranged in the downstream space, thereby heating these devices with the cooling air at a higher temperature to make it higher than the hydrogen exhaust temperature of the fuel cell, thereby suppressing condensation.

[0026] The fuel cell system includes a fuel cell that generates electricity by reacting hydrogen with air, a hydrogen system that supplies hydrogen required for power generation to the fuel cell, a reaction air system that supplies reaction air to the fuel cell, and a cooling air system that supplies cooling air to the fuel cell to cool the heat generated by power generation.

[0027] The fuel cell may be a single cell (battery cell) having only one fuel cell, or may be a fuel cell stack (battery stack) which is a stacked body in which a plurality of cells are stacked.

[0028] In the present disclosure, there are cases where both a battery cell and a fuel cell stack are referred to as a fuel cell.

[0029] The number of stacked cells in the fuel cell stack is not particularly limited, and may be, for example, 2 to several hundred.

[0030] The fuel cell stack may include corrugated cooling fins serving as cooling air flow paths in each cell.

[0031] The fuel cell stack may have a current collecting plate, a pressure plate, etc. at the end portions in the stacking direction.

[0032] The fuel cell has a reaction air flow path (oxidant gas flow path) and a cooling air flow path (cooling gas flow path) with independent flow paths for reaction air and cooling air, and may further have a hydrogen flow path (fuel gas flow path).

[0033] The independent flow path structure of reaction air and cooling air means that there is no communication between the flow paths from the supply of air to the fuel cell to the exhaust of air from the fuel cell. In addition, the flow path for exhausting the air exhausted from the fuel cell to the outside of the fuel cell system may be independent or not.

[0034] The cell may also include a flow path structure that allows the reaction air and the cooling air to flow so that the flow of the cooling air intersects with the flow of the reaction air in a plan view. The flow of the cooling air and the flow of the reaction air may intersect or be orthogonal.

[0035] The battery cell may have a power generation unit.

[0036] The shape of the power generation unit may be a rectangle in a plan view.

[0037] The power generation unit may be a membrane electrode assembly (MEA) including an electrolyte membrane and two electrodes.

[0038] The electrolyte membrane may also be a solid polymer electrolyte membrane. As the solid polymer electrolyte membrane, for example, a fluorine electrolyte membrane such as a film of perfluorosulfonic acid containing water, and a hydrocarbon electrolyte membrane may be cited. As the electrolyte membrane, for example, a Nafion membrane (manufactured by DuPont) may also be used.

[0039] The two electrodes are the anode (fuel or hydrogen) and the cathode (oxygen or air).

[0040] The electrode includes a catalyst layer and may include a gas diffusion layer as required, and the power generation unit may be a membrane electrode gas diffusion layer assembly (MEGA).

[0041] The catalyst layer may include a catalyst including a catalyst metal that promotes an electrochemical reaction, an electrolyte having proton conductivity, and a carrier having electron conductivity.

[0042] As the catalyst metal, for example, platinum (Pt) and alloys composed of Pt and other metals (for example, Pt alloys mixed with cobalt, nickel, etc.) can be used. The catalyst metal used as the cathode catalyst and the catalyst metal used as the anode catalyst may be the same or different.

[0043] The electrolyte may be a fluorine-based resin or the like. For example, a Nafion solution or the like may be used as the fluorine-based resin.

[0044] The above-mentioned catalyst metal is supported on a carrier, and in each catalyst layer, the carrier supporting the catalyst metal (catalyst-supporting carrier) and the electrolyte may be present in a mixed state.

[0045] Examples of the carrier for supporting the catalyst metal include carbon materials such as carbon generally available on the market.

[0046] The gas diffusion layer may be a conductive member having pores or the like.

[0047] Examples of the conductive member include carbon porous bodies such as carbon cloth and carbon paper, and metal porous members such as metal mesh and foamed metal.

[0048] The cells of the fuel cell may also include a membrane.

[0049] The diaphragm collects the current generated by power generation and functions as a partition. In the battery cell of a fuel cell, the diaphragm is usually arranged on both sides of the stacking direction of the power generation part in a way that a pair of diaphragms sandwich the power generation part. One side of the pair of diaphragms is the anode diaphragm and the other side is the cathode diaphragm.

[0050] The anode separator may have grooves serving as hydrogen flow paths on the surface on the power generation portion side, and may have grooves serving as cooling air flow paths on the surface on the opposite side to the power generation portion.

[0051] The cathode separator may have grooves serving as reaction air flow paths on the surface facing the power generation portion, and may have grooves serving as cooling air flow paths on the surface facing the opposite side to the power generation portion.

[0052] The separator may have holes constituting manifolds such as supply holes and discharge holes for allowing the fluid to flow in the stacking direction of the battery cells.

[0053] The separator may be, for example, dense carbon obtained by compressing carbon to be airtight, or press-formed metal (for example, iron, titanium, stainless steel, etc.).

[0054] The battery cell may also be provided with an insulating resin frame disposed on the outside (periphery) of the surface direction of the membrane electrode assembly between the anode separator and the cathode separator. The resin frame is formed into a plate-like and frame-like shape using a thermoplastic resin, and the anode separator and the cathode separator are sealed while the membrane electrode assembly is maintained in its central area. As the resin frame, for example, resins such as PE, PP, PET, and PEN can be used. The resin frame may also be a three-layer sheet body consisting of three layers in which an adhesive layer is disposed on the surface layer.

[0055] The fuel cell system may also include a control device, which controls the reaction air system, the hydrogen system, the cooling air system, etc., and may also control the entire fuel cell system.

[0056] The control device physically has, for example, a processing unit such as a CPU (central processing unit), a ROM (read-only memory) for storing control programs and control data processed by the CPU, a storage device such as a RAM (random access memory) mainly used as various work areas for control processing, and an input / output interface. It can also be an ECU (electronic control unit), etc.

[0057] The hydrogen system supplies hydrogen as a fuel gas to the fuel cell and adjusts the flow rate of the hydrogen. The hydrogen system may also have a circulation system for circulating the hydrogen supplied to the fuel cell. The hydrogen system includes a hydrogen tank, a hydrogen inlet valve, an ejector, a hydrogen purge valve, a hydrogen piping, etc. As a circulation system, the hydrogen system may also include a gas-liquid separator, a hydrogen pump, an ejector, and a hydrogen circulation piping, etc. The hydrogen circulation piping is connected to the gas-liquid separator, the hydrogen pump or the ejector in sequence from the hydrogen outlet of the fuel cell to the hydrogen inlet of the fuel cell, thereby making hydrogen circulation possible.

[0058] The reaction air system supplies reaction air as an oxidant gas to the fuel cell and adjusts the flow rate of the reaction air.

[0059] The reaction air system may also have an inlet side sealing valve at the reaction air inlet of the fuel cell and an outlet side sealing valve at the reaction air outlet of the fuel cell. The inlet side sealing valve and the outlet side sealing valve may be arranged in the upstream side space in the housing or in the downstream side space in the housing.

[0060] In the present disclosure, the fuel cell has an independent flow path structure for reaction air and cooling air, and in the reaction air system, valves (inlet side sealing valve and outlet side sealing valve) are set at the inlet and outlet of the reaction air of the fuel cell, thereby enabling the fuel cell to seal the cathode of the fuel cell with a smaller volume than the case of having a flow path structure shared by the reaction air and the cooling air.

[0061] The reaction air system may include a reaction air intake port and a reaction air supply mechanism. A pressure loss body (air filter) may be provided at the reaction air intake port.

[0062] The reaction air supply mechanism may also be an air compressor, an air pump, an air blower, an air fan, etc.

[0063] The cooling air system supplies cooling air as cooling gas to the fuel cell and adjusts the flow rate of the cooling air.

[0064] The cooling air system may include a cooling air supply mechanism for generating a flow of cooling air. The cooling air system may include an air intake port for sucking air from the outside. A pressure loss body (air filter) may be provided at the air intake port.

[0065] The cooling air supply mechanism may also be an air compressor, an air pump, an air blower, an air fan, etc.

[0066] The fuel cell system has a housing.

[0067] The housing houses the fuel cell.

[0068] The housing has an upstream space as an air intake side and a downstream space as an air exhaust side in the flow direction of cooling air in the housing with the fuel cell as a reference. The housing has an air intake port and an air exhaust port of the cooling air system.

[0069] The upstream space is a partitioned space from the air intake port to the fuel cell, and the downstream space is a partitioned space from the fuel cell to the cooling air supply mechanism.

[0070] In the first embodiment, the circulation system of the hydrogen system is arranged in the downstream space. In the first embodiment, the reaction air system may or may not have an inlet-side sealing valve and an outlet-side sealing valve.

[0071] In the second embodiment, the hydrogen purge valve of the hydrogen system is arranged in the downstream space. In the second embodiment, the hydrogen system may or may not have a circulation system. In the second embodiment, the reaction air system may or may not have an inlet side sealing valve and an outlet side sealing valve.

[0072] In the third embodiment, at least the outlet sealing valve in the reaction air system only needs to be arranged in the downstream space, and both the inlet sealing valve and the outlet sealing valve may be arranged in the downstream space. In the third embodiment, the hydrogen system may or may not have a circulation system.

[0073] In the fourth embodiment, the circulation system and the hydrogen purge valve of the hydrogen system are arranged in the downstream space. In the fourth embodiment, the reaction air system may or may not have an inlet-side sealing valve and an outlet-side sealing valve.

[0074] In the fifth embodiment, the circulation system of the hydrogen system, the hydrogen purge valve, and at least the outlet side sealing valve in the reaction air system only need to be arranged in the downstream side space. The circulation system of the hydrogen system, the hydrogen purge valve, and the outlet side sealing valve of the reaction air system can also be arranged in the downstream side space. The circulation system of the hydrogen system, the hydrogen purge valve, and the inlet side sealing valve and the outlet side sealing valve of the reaction air system can also be arranged in the downstream side space.

[0075] Figure 1 It is an exploded perspective schematic diagram showing an example of a single cell of a fuel cell included in the fuel cell system of the present disclosure.

[0076] Figure 1 The cell 1 shown in the figure has cooling fins (cooling air flow path) 2 which serve as a flow path for cooling air (cooling gas) 7, a reaction air inlet 3, a reaction air outlet 4, a hydrogen inlet 5, a hydrogen outlet 6, two diaphragms 11, and an MEA and a resin frame 12 sandwiched between the two diaphragms 11. Figure 1 As shown, the cell 1 of the fuel cell has a flow path structure in which the reaction air 9 and the cooling air 7 are independent.

[0077] Figure 2 It is a perspective schematic diagram showing an example of a fuel cell stack included in the fuel cell system of the present disclosure.

[0078] Figure 2 The fuel cell stack shown is a stacked body in which a plurality of battery cells 1 are stacked, and includes current collector plates 13 and pressure plates 14 at both ends in the stacking direction.

[0079] Figure 3 (1) is a system configuration diagram showing an example of a fuel cell system of the present disclosure, Figure 3 (2) is a system configuration diagram showing an example of a conventional fuel cell system.

[0080] Figure 3 The fuel cell system shown includes a housing 50, a fuel cell stack 10, a reaction air system 20, a cooling air system 30, and a hydrogen system 40. Figure 3 For the sake of convenience, the description of the reaction air system 20 is omitted. The cooling air system 30 includes a cooling fan 31 and an air intake port 32. The hydrogen system 40 includes a hydrogen tank 41, a hydrogen inlet valve 42, a gas-liquid separator 43, a hydrogen purge valve 44, and a hydrogen pump 45. The air intake port 32 may also include an air intake filter.

[0081] The housing 50 is based on the fuel cell stack 10, and has an upstream space 52 and a downstream space 53 separated by a partition wall 51 in the flow direction of the cooling air 7 in the housing 50. The upstream space 52 is a space separated from the air intake port 32 to the fuel cell stack 10, and the downstream space 53 is a space separated from the fuel cell stack 10 to the cooling fan 31.

[0082] for Figure 3 For the fuel cell system shown in (1), the hydrogen inlet valve 42, hydrogen purge valve 44, gas-liquid separator 43, hydrogen pump 45, and piping including the hydrogen circulation piping indicated by dotted lines of the hydrogen system are housed in the downstream side space 53 of the cooling air.

[0083] Thus, the hydrogen outlet temperature T3 of the fuel cell stack 10 is lower than the average cooling air outlet temperature T2 of the fuel cell stack 10 .

[0084] Since the exhaust hydrogen temperature T3 is lower than the temperature T2 of the piping of the circulation system of the hydrogen system, condensation in the circulation system can be prevented. The exhaust hydrogen containing liquid droplets at temperature T3 passes through the gas-liquid separator 43 and becomes a mixed gas of hydrogen and water vapor at a dew point T3, but the piping of the circulation system is then heated to T2, so that hydrogen can flow to the inlet of the fuel cell stack 10 without condensation.

[0085] like Figure 3 As shown in (2), when the circulation system of the hydrogen system is set in the upstream space 52 or is exposed to the external air outside the shell (≈T1), the dew point T3 of the hydrogen in the circulation system is higher than the piping temperature T1 of the circulation system, and the hydrogen cools during the circulation to produce condensation. Water blockage occurs in the piping of the circulation system, resulting in increased pressure loss and freezing and closure at low temperatures.

[0086] In an air-cooled fuel cell, a large amount of cooling air is directly drawn into the fuel cell. Therefore, by placing at least the circulation system of the hydrogen system in the downstream space 53 of the cooling air, condensation in the circulation system of the hydrogen system can be prevented. In addition, by using hot air directly connected to the fuel cell, compact handling can be achieved without additional equipment.

[0087] Figure 4 (1) is a system configuration diagram showing another example of the fuel cell system disclosed in the present invention. Figure 4 (2) is a system configuration diagram showing another example of a conventional fuel cell system.

[0088] Figure 4 The fuel cell system shown includes a housing 50, a fuel cell stack 10, a reaction air system 20, a cooling air system 30, and a hydrogen system 40. Figure 4For convenience, the description of the hydrogen system 40 is omitted. The reaction air system 20 includes a reaction air intake port 21, an air blower 22, an inlet side sealing valve 23, and an outlet side sealing valve 24. The cooling air system 30 includes a cooling fan 31 and an intake port 32. The intake port 32 may also include an intake filter. Figure 4 The fuel cell system shown in the figure is provided with sealing valves 23 and 24 at the inlet and outlet of the reaction air system 20, and with independent air supply mechanisms 22 and 31 in the reaction air system 20 and the cooling air system 30. The reaction air intake port 21 may be provided with an air filter.

[0089] The fuel cell stack 10 has a flow path structure in which reaction air and cooling air flow independently.

[0090] The housing 50 is based on the fuel cell stack 10, and has an upstream space 52 and a downstream space 53 separated by a partition wall 51 in the flow direction of the cooling air 7 in the housing 50. The upstream space 52 is a space separated from the air intake port 32 to the fuel cell stack 10, and the downstream space 53 is a space separated from the fuel cell stack 10 to the cooling fan 31.

[0091] for Figure 4 In the fuel cell system shown in (1), the inlet-side sealing valve 23, the outlet-side sealing valve 24, and the piping of the reaction air system 20 are accommodated in the downstream-side space 53 of the cooling air.

[0092] Thus, the reaction air outlet temperature T3 of the fuel cell stack 10 is lower than the average cooling air outlet temperature T2 of the fuel cell stack 10 .

[0093] In addition, since liquid water does not adhere to the air blower 22 and the inlet-side sealing valve 23, they can be located in any space.

[0094] like Figure 4 As shown in (2), when the outlet sealing valve 24 of the reaction air system 20 is installed in the upstream space 52 or is exposed to the outside air (≈T1) outside the housing, the dew point T3 of the reaction air in the reaction air system is higher than the piping temperature T1 of the reaction air system, and the reaction air is cooled to generate condensation. Water blockage occurs in the piping of the reaction air system, resulting in an increase in pressure loss and freezing and closure at low temperatures.

Claims

1. A fuel cell system, which is an air-cooled fuel cell system, characterized in that: The fuel cell system includes a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell. The fuel cell has a reaction air flow path and a cooling air flow path in a structure in which the reaction air and the cooling air have independent flow paths. The hydrogen system includes a circulation system for circulating the hydrogen supplied to the fuel cell. The fuel cell system comprises a housing, The housing accommodates the fuel cell, The housing has an upstream space and a downstream space in the flow direction of the cooling air in the housing with the fuel cell as a reference. The circulation system of the hydrogen system is arranged in the downstream space.

2. A fuel cell system, which is an air-cooled fuel cell system, characterized in that: The fuel cell system includes a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell. The fuel cell has a reaction air flow path and a cooling air flow path in a structure in which the reaction air and the cooling air have independent flow paths. The hydrogen system has a hydrogen purge valve at the hydrogen outlet of the fuel cell, The fuel cell system comprises a housing, The housing accommodates the fuel cell, The housing has an upstream space and a downstream space in the flow direction of the cooling air in the housing with the fuel cell as a reference. The hydrogen purge valve of the hydrogen system is arranged in the downstream space.

3. A fuel cell system, which is an air-cooled fuel cell system, characterized in that: The fuel cell system includes a fuel cell, a hydrogen system for supplying hydrogen to the fuel cell, a reaction air system for supplying reaction air to the fuel cell, and a cooling air system for supplying cooling air to the fuel cell. The fuel cell has a reaction air flow path and a cooling air flow path in a structure in which the reaction air and the cooling air have independent flow paths. The reaction air system has an inlet-side sealing valve at the reaction air inlet of the fuel cell and an outlet-side sealing valve at the reaction air outlet of the fuel cell. The fuel cell system comprises a housing, The housing accommodates the fuel cell, The housing has an upstream space and a downstream space in the flow direction of the cooling air in the housing with the fuel cell as a reference. At least the outlet-side sealing valve in the reaction air system is arranged in the downstream-side space.

4. The fuel cell system according to claim 1, characterized in that: The hydrogen system has the circulation system and a hydrogen purge valve at the hydrogen outlet of the fuel cell. The circulation system of the hydrogen system and the hydrogen purge valve are arranged in the downstream space.

5. The fuel cell system according to claim 1, characterized in that: The hydrogen system has the circulation system and a hydrogen purge valve at the hydrogen outlet of the fuel cell. The reaction air system has an inlet-side sealing valve at the reaction air inlet of the fuel cell and an outlet-side sealing valve at the reaction air outlet of the fuel cell. The circulation system of the hydrogen system, the hydrogen purge valve, and at least the outlet-side sealing valve in the reaction air system are arranged in the downstream-side space.

6. The fuel cell system according to claim 1, characterized in that: The fuel cell has at least one single cell, which has an anode diaphragm, a power generation unit, and a cathode diaphragm in sequence. The cathode diaphragm has the reaction air flow path on one side of the power generation unit and the cooling air flow path on the opposite side of the power generation unit.

7. The fuel cell system according to claim 6, characterized in that: The single cell has corrugated cooling fins as the cooling air flow path.

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