Air-cooled fuel cell system

Abstract

To provide a fuel cell system that can prevent the occurrence of dew condensation on or freezing of a valve or piping.SOLUTION: An air-cooled fuel cell system is provided. The fuel cell system comprises a fuel cell, a hydrogen system that supplies hydrogen 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. The fuel cell has a reaction air channel and a cooling air channel having independent channel structures of the reaction air and the cooling air. The hydrogen system has a circulation system that circulates the hydrogen to be supplied to the fuel cell. The fuel cell system has a case. The case accommodates the fuel cell. The case has an upstream side space and a downstream side space in a flow direction of the cooling air in the case with respect to the fuel cell. The circulation system of the hydrogen system is arranged in the downstream side space.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to air-cooled fuel cell systems. [Background technology]

[0002] Various technologies have been proposed regarding fuel cells (FCs), such as those disclosed in Patent Documents 1-4. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-185248 A [Patent Document 2] JP 2006-209994 A [Patent Document 3] JP 2022-185251 A [Patent Document 4] JP 2022-185247 A Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, no consideration is given to temperature management of the reaction air system and hydrogen system, and condensation may occur when the fuel cell system is not in operation, causing valves and piping to freeze if the environmental temperature of the fuel cell system is low. In addition, in order to suppress condensation, additional configuration for suppressing condensation is required, which makes it unavoidable to increase the size of the fuel cell system.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has as its main object to provide an air-cooled fuel cell system that can suppress the occurrence of condensation and freezing of valves and piping. [Means for solving the problem]

[0006] In a first embodiment of the present disclosure, there is provided an air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the hydrogen system has a circulation system that circulates the hydrogen to be supplied to the fuel cell, The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, The fuel cell system is characterized in that the circulation system of the hydrogen system is disposed in the downstream space.

[0007] In a second embodiment of the present disclosure, there is provided an air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the hydrogen system has a hydrogen purge valve at the hydrogen outlet of the fuel cell; The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, The fuel cell system is characterized in that the hydrogen purge valve of the hydrogen system is disposed in the downstream space.

[0008] In a third embodiment of the present disclosure, there is provided an air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the reaction air system has an inlet-side sealing valve at an inlet of the reaction air of the fuel cell, and an outlet-side sealing valve at an outlet of the reaction air of the fuel cell, The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, The present invention provides a fuel cell system, characterized in that at least the outlet side sealing valve of the reaction air system is disposed in the downstream side space.

[0009] In a fourth embodiment of the present disclosure, in the first embodiment, 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 may be disposed in the downstream space.

[0010] In a fifth embodiment of the present disclosure, in the first embodiment, 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 an inlet of the reaction air of the fuel cell, and an outlet-side sealing valve at an outlet of the reaction air of the fuel cell, The circulation system of the hydrogen system, the hydrogen purge valve, and at least the outlet side sealing valve of the reaction air system may be disposed in the downstream space. Effect of the Invention

[0011] The fuel cell system of the present disclosure can suppress the occurrence of condensation and freezing of valves and piping. [Brief description of the drawings]

[0012] [Figure 1] 1 is an exploded perspective view showing an example of a single cell of a fuel cell provided in a fuel cell system according to the present disclosure; [Diagram 2] 1 is a schematic perspective view showing an example of a fuel cell stack provided in a fuel cell system according to the present disclosure. [Diagram 3] FIG. 1A is a system configuration diagram showing an example of a fuel cell system according to the present disclosure, and FIG. 1B is a system configuration diagram showing an example of a conventional fuel cell system. [Figure 4] FIG. 1(1) is a system configuration diagram showing another example of a fuel cell system according to the present disclosure, and FIG. 1(2) is a system configuration diagram showing another example of a conventional fuel cell system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described. Note that matters other than those specifically mentioned in this specification and necessary for implementing the present disclosure (for example, the general configuration and manufacturing process of a fuel cell system that does not characterize the present disclosure) can be understood as design matters of a person skilled in the art based on the prior art in the field. The present disclosure can be implemented based on the contents disclosed in this specification and the technical common sense in the field. Furthermore, the dimensional relationships (length, width, thickness, etc.) in the drawings do not reflect the actual dimensional relationships. In the present disclosure, the gas supplied to the anode of the fuel cell is a fuel gas (anode gas), and the gas supplied to the cathode of the fuel cell is an oxidant gas (cathode gas). The fuel gas is a gas that mainly contains hydrogen and may be hydrogen. The oxidant gas is a gas that contains oxygen and may be oxygen, air, etc. In the present disclosure, air as the oxidant gas is referred to as reaction air, and air as the cooling gas is referred to as cooling air.

[0014] The present disclosure provides an air-cooled fuel cell system, comprising: the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the hydrogen system has a circulation system that circulates the hydrogen to be supplied to the fuel cell, The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, The fuel cell system is characterized in that the circulation system of the hydrogen system is disposed in the downstream space.

[0015] If a heater is installed to heat supply devices such as valves in order to prevent condensation and clogging, problems such as an increase in the size of the case, an increase in the cost of the device, and an increase in power consumption occur. According to the present disclosure, by disposing supply devices such as valves in the downstream space in the case of an air-cooled fuel cell system, the temperature of the cooling air in the downstream space in the case is high, so that condensation, clogging, and subsequent freezing are suppressed. For example, in order to suppress condensation and clogging in the hydrogen system, the piping after gas-liquid separation and the hydrogen pump of the circulation system are disposed in the downstream space, and these can be warmed by the high-temperature cooling air, and the temperature is raised higher than the hydrogen exhaust temperature of the fuel cell, thereby suppressing condensation.

[0016] The fuel cell system includes a fuel cell that generates electricity by reacting hydrogen with air, a hydrogen system that supplies the hydrogen needed to generate electricity 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.

[0017] The fuel cell may have only one unit cell (cell) of the fuel cell, or may be a fuel cell stack (stack) which is a laminate of a plurality of cells. In this disclosure, both cells and fuel cell stacks may be referred to as fuel cells. The number of cells stacked in the fuel cell stack is not particularly limited, and may be, for example, from 2 to several hundred. The fuel cell stack may have wavy cooling fins for each cell to provide cooling air flow paths. The fuel cell stack may have current collector plates, pressure plates, etc. at the ends in the stacking direction.

[0018] A fuel cell has a reactant air flow path (oxidant gas flow path) and a cooling air flow path (cooling gas flow path) with independent flow path structures for the reactant air and the cooling air, and may further have a hydrogen gas flow path (fuel gas flow path). A flow path structure in which the reaction air and the cooling air are separate means that there is no sharing of air between the flow paths from the supply of air to the fuel cell to the exhaust of air from the fuel cell. Note that the flow path for exhausting the air exhausted from the fuel cell to the outside of the fuel cell system may or may not be separate.

[0019] The cell may have a flow path structure for passing the reaction air and the cooling air such that the flow of the cooling air and the flow of the reaction air cross each other in a plan view. The flow of the cooling air and the flow of the reaction air may cross each other or be perpendicular to each other. The cell may have a power generation portion. The power generating section may have a rectangular shape in a plan view. The power generating section may be a membrane electrode assembly (MEA) including an electrolyte membrane and two electrodes. The electrolyte membrane may be a solid polymer electrolyte membrane. Examples of the solid polymer electrolyte membrane include a fluorine-based electrolyte membrane such as a thin film of perfluorosulfonic acid containing water, and a hydrocarbon-based electrolyte membrane. The electrolyte membrane may be, for example, a Nafion membrane (manufactured by DuPont). The two electrodes are the anode (fuel electrode or hydrogen electrode) and the cathode (oxygen electrode or air electrode). The electrodes include a catalyst layer and may include a gas diffusion layer as necessary, and the power generating portion may be a membrane electrode gas diffusion layer assembly (MEGA). The catalyst layer includes a catalyst, and the catalyst may include a catalytic metal that promotes an electrochemical reaction, an electrolyte having proton conductivity, and a carrier having electron conductivity. Examples of the catalytic metal that can be used include platinum (Pt) and alloys of Pt with other metals (e.g., Pt alloys mixed with cobalt and nickel, etc.) The catalytic metal used as the cathode catalyst and the catalytic metal used as the anode catalyst may be the same or different. The electrolyte may be a fluorine-based resin, etc. As the fluorine-based resin, for example, a Nafion solution, etc. may be used. The catalytic metal is supported on a carrier, and in each catalyst layer, the carrier supporting the catalytic metal (catalyst-supporting carrier) and the electrolyte may be mixed. The support for supporting the catalytic metal may be, for example, a carbon material such as carbon that is generally available commercially. The gas diffusion layer may be a conductive member having air holes. Examples of the conductive member include porous carbon materials such as carbon cloth and carbon paper, and porous metal members such as metal mesh and foamed metal. The fuel cell may include a separator. The separators collect the electric current generated by power generation and function as partition walls. In a fuel cell, the separators are usually arranged on both sides of the power generation section in the stacking direction so that the power generation section is sandwiched between a pair of separators. One of the pair of separators is an anode separator and the other is a cathode separator. The anode separator may have grooves that serve as hydrogen gas flow paths on the surface facing the power generation section. The cathode separator may have grooves that serve as reaction air channels on the surface facing the power generation section. The separator may have holes forming manifolds such as supply holes and discharge holes for circulating a fluid in the stacking direction of the cells. The separator may be made of, for example, dense carbon obtained by compressing carbon to make it gas impermeable, or a press-molded metal (for example, iron, titanium, stainless steel, etc.). The cell may include an insulating resin frame disposed on the outer side (periphery) of the membrane electrode assembly in the planar direction between the anode separator and the cathode separator. The resin frame is molded into a plate-like and frame-like shape using a thermoplastic resin, and seals the gap between the anode separator and the cathode separator while holding the membrane electrode assembly in its central region. For the resin frame, for example, a resin such as PE, PP, PET, or PEN can be used. The resin frame may be a three-layer sheet composed of three layers with an adhesive layer disposed on the surface layer.

[0020] The fuel cell system may include a control device. The control device may control the reaction air system, the hydrogen system, the cooling air system, etc., and may control the entire fuel cell system. The control device physically has, for example, a processing device such as a CPU (central processing unit), a ROM (read-only memory) that stores control programs and control data processed by the CPU, a storage device such as a RAM (random access memory) that is mainly used as various working areas for control processing, and an input / output interface, and may be an ECU (electronic control unit), etc.

[0021] The hydrogen system supplies hydrogen to the fuel cell as a fuel gas and adjusts the flow rate of the hydrogen. The hydrogen system may have a circulation system that circulates hydrogen supplied to the fuel cell. The hydrogen system includes a hydrogen tank, a hydrogen inlet valve, an injector, a hydrogen purge valve, hydrogen piping, etc., and may include a gas-liquid separator, a hydrogen pump, an ejector, and a hydrogen circulation piping, etc., as a circulation system. The hydrogen circulation piping connects the gas-liquid separator, the hydrogen pump, or the ejector in this order from the hydrogen outlet of the fuel cell to the hydrogen inlet of the fuel cell, enabling hydrogen circulation.

[0022] The reaction air system supplies reaction air to the fuel cell as an oxidant gas, and adjusts the flow rate of the reaction air. The reaction air system may have an inlet sealing valve at the inlet of the reaction air of the fuel cell and an outlet sealing valve at the outlet of the reaction air of the fuel cell. The inlet sealing valve and the outlet sealing valve may be disposed in an upstream space in the case or in a downstream space in the case. In the present disclosure, the fuel cell has an independent flow path structure for the reaction air and the cooling air, and valves (an inlet side sealing valve and an outlet side sealing valve) are installed at the inlet and outlet of the reaction air of the fuel cell in the reaction air system, making it possible to seal the cathode of the fuel cell with a smaller volume than when the fuel cell has a flow path structure in which the reaction air and the cooling air are common.

[0023] The reaction air system may have a reaction air intake port and a reaction air blowing means. A pressure loss body (air filter) may be installed in the reaction air intake port. The reaction air blowing means may be an air compressor, an air pump, an air blower, an air fan, or the like.

[0024] The cooling air system supplies cooling air as a cooling gas to the fuel cell, and adjusts the flow rate of the cooling air. The cooling air system may have a cooling air blowing means for generating a flow of cooling air. The cooling air system has an intake port for drawing air from the outside. A pressure loss body (air filter) may be installed in the intake port. The cooling air blowing means may be an air compressor, an air pump, an air blower, an air fan, or the like.

[0025] The fuel cell system has a case. The case houses a fuel cell. The case has an upstream space on the intake side and a downstream space on the exhaust side in the direction of cooling air flow within the case relative to the fuel cell. The case has an intake port and an exhaust port for a cooling air system. 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 blowing means.

[0026] 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.

[0027] In the second embodiment, the hydrogen purge valve of the hydrogen system is disposed 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 closing valve and an outlet-side closing valve.

[0028] In the third embodiment, at least the outlet sealing valve of the reaction air system may be disposed in the downstream space, and both the inlet sealing valve and the outlet sealing valve may be disposed in the downstream space. In the third embodiment, the hydrogen system may or may not have a circulation system.

[0029] In the fourth embodiment, the hydrogen circulation system and the hydrogen purge valve are disposed in the downstream space. In the fourth embodiment, the reaction air system may or may not have an inlet-side closing valve and an outlet-side closing valve.

[0030] In the fifth embodiment, it is sufficient that at least the outlet side sealing valve of the hydrogen system circulation system, the hydrogen purge valve, and the reaction air system are arranged in the downstream space, and the hydrogen system circulation system, the hydrogen purge valve, and the outlet side sealing valve of the reaction air system may be arranged in the downstream space, or the hydrogen system circulation system, the hydrogen purge valve, and the inlet side sealing valve and the outlet side sealing valve of the reaction air system may be arranged in the downstream space.

[0031] FIG. 1 is an exploded perspective view showing an example of a single cell of a fuel cell provided in a fuel cell system of the present disclosure. 1 includes cooling fins (cooling air flow paths) 2 that serve as flow paths for cooling air (cooling gas) 7, a reaction air inlet 3, a reaction air outlet 4, a hydrogen gas inlet 5, a hydrogen gas outlet 6, two separators 11, and an MEA and a resin frame 12 sandwiched between the two separators 11. As shown in FIG. 1, the fuel cell 1 has a flow path structure in which the reaction air 9 and the cooling air 7 are independent of each other.

[0032] FIG. 2 is a schematic perspective view showing an example of a fuel cell stack included in the fuel cell system of the present disclosure. The fuel cell stack shown in FIG. 2 is a laminate in which a plurality of cells 1 are stacked, and includes a current collector plate 13 and a pressure plate 14 on both ends in the stacking direction.

[0033] FIG. 3(1) is a system configuration diagram showing an example of a fuel cell system according to the present disclosure, and (2) is a system configuration diagram showing an example of a conventional fuel cell system. The fuel cell system shown in Fig. 3 includes a case 50, a fuel cell stack 10, a reaction air system 20, a cooling air system 30, and a hydrogen system 40. For convenience, the reaction air system 20 is omitted from Fig. 3. The cooling air system 30 includes a cooling fan 31 and an 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 intake port 32 may include an intake filter. Case 50 has an upstream space 52 and a downstream space 53 separated by a partition wall 51 in the flow direction of cooling air 7 inside case 50 with respect to fuel cell stack 10. The upstream space 52 is a separated space from the air intake port 32 to the fuel cell stack 10, and the downstream space 53 is a separated space from the fuel cell stack 10 to the cooling fan 31.

[0034] The fuel cell system shown in FIG. 3(1) has a hydrogen inlet valve 42 for the hydrogen system, a hydrogen purge valve 44, a gas-liquid separator 43 for the circulation system, a hydrogen pump 45, and piping including hydrogen circulation piping shown by dotted lines, housed in a space 53 downstream of the cooling air. As a result, the hydrogen outlet temperature T3 of the fuel cell stack 10 becomes lower than the average cooling air outlet temperature T2 of the fuel cell stack 10. Since the temperature T3 of the exhaust hydrogen is lower than the temperature T2 of the piping in the hydrogen circulation system, condensation in the circulation system can be prevented. The exhaust hydrogen containing droplets at temperature T3 passes through gas-liquid separator 43 and becomes a mixed gas of hydrogen and water vapor at the dew point T3, but the piping in the circulation system is then warmed to T2, allowing hydrogen to flow to the inlet of fuel cell stack 10 without condensation. As shown in Fig. 3(2), when the hydrogen circulation system is installed in the upstream space 52 or exposed to the outside air (≈T1) outside the case, the dew point T3 of the hydrogen gas in the circulation system becomes higher than the piping temperature T1 of the circulation system, and the hydrogen gas cools during circulation and condenses. Water puddles may form in the piping of the circulation system, causing an increase in pressure loss or freezing and clogging at low temperatures. In an air-cooled fuel cell, a large amount of cooling air is drawn directly into the fuel cell, so by providing at least the hydrogen circulation system in the space 53 downstream of the cooling air, condensation in the hydrogen circulation system can be prevented, and by using hot air directly connected to the fuel cell, measures can be taken compactly without additional equipment.

[0035] FIG. 4(1) is a system configuration diagram showing another example of the fuel cell system of the present disclosure, and (2) is a system configuration diagram showing another example of a conventional fuel cell system. The fuel cell system shown in FIG. 4 includes a case 50, a fuel cell stack 10, a reaction air system 20, a cooling air system 30, and a hydrogen system 40. In FIG. 4, the hydrogen system 40 is omitted for convenience. 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 include an intake filter. The fuel cell system shown in FIG. 4 includes sealing valves 23 and 24 at the inlet and outlet of the reaction air system 20, and includes independent blowing means 22 and 31 for the reaction air system 20 and the cooling air system 30. The reaction air intake port 21 may include an air filter. The fuel cell stack 10 has a flow path structure in which reaction air and cooling air have independent flow paths. Case 50 has an upstream space 52 and a downstream space 53 separated by a partition wall 51 in the flow direction of cooling air 7 inside case 50 with respect to fuel cell stack 10. The upstream space 52 is a separated space from the air intake port 32 to the fuel cell stack 10, and the downstream space 53 is a separated space from the fuel cell stack 10 to the cooling fan 31. In the fuel cell system shown in FIG. 4(1), the inlet side sealing valve 23, the outlet side sealing valve 24, and piping of the reaction air system 20 are housed in a space 53 downstream of the cooling air. As a result, the reaction air outlet temperature T3 of the fuel cell stack 10 becomes lower than the average cooling air outlet temperature T2 of the fuel cell stack 10. In addition, the air blower 22 and the inlet side sealing valve 23 may be located in either space since liquid water will not adhere to them. 4(2), when the outlet side sealing valve 24 of the reaction air system 20 is installed in the upstream space 52 or exposed to the outside air (≈T1) outside the case, the dew point T3 of the reaction air in the reaction air system becomes higher than the piping temperature T1 of the reaction air system, and the reaction air cools and condenses. Puddles may form in the piping of the reaction air system, increasing the pressure loss and causing freezing blockage at low temperatures. [Explanation of symbols]

[0036] 1. Cell 2. Cooling fins (cooling air flow path) 3.Reaction air inlet 4.Reaction air outlet 5. Hydrogen gas inlet 6. Hydrogen gas outlet 7. Cooling air (cooling gas) 8. Hydrogen gas 9.Reaction air 10. Fuel Cell Stack 11. Separator 12.MEA, resin frame 13. Current collector plate 14. Pressure plate 20.Reaction air system 21.Reaction air intake 22. Air Blower 23. Inlet side sealing valve 24.Outlet side sealing valve 30. Cooling air system 31. Cooling fan 32. Air intake 40. Hydrogen 41. Hydrogen tank 42. Hydrogen inlet valve 43. Gas-liquid separator 44. Hydrogen purge valve 45. Hydrogen pump 50. Case 51. Bulkhead 52. Upstream space 53. Downstream space

Claims

1. An air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the hydrogen system has a circulation system that circulates the hydrogen to be supplied to the fuel cell, The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, a circulation system for the hydrogen system disposed in the downstream space;

2. An air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the hydrogen system has a hydrogen purge valve at the hydrogen outlet of the fuel cell; The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, a hydrogen purge valve for the hydrogen system disposed in the downstream space.

3. An air-cooled fuel cell system, the fuel cell system includes a fuel cell, a hydrogen system that supplies hydrogen 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; the fuel cell has a reaction air flow path and a cooling air flow path having an independent flow path structure for the reaction air and the cooling air, the reaction air system has an inlet-side sealing valve at an inlet of the reaction air of the fuel cell, and an outlet-side sealing valve at an outlet of the reaction air of the fuel cell, The fuel cell system has a case, the case accommodates the fuel cell; the case has an upstream space and a downstream space in a flow direction of the cooling air inside the case based on the fuel cell, A fuel cell system, characterized in that at least the outlet side sealing valve of the reaction air system is disposed in the downstream side space.

4. the hydrogen system includes the circulation system and a hydrogen purge valve at the hydrogen outlet of the fuel cell; 2. The fuel cell system according to claim 1, wherein the circulation system of the hydrogen system and the hydrogen purge valve are disposed in the downstream space.

5. the hydrogen system includes 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 an inlet of the reaction air of the fuel cell, and an outlet-side sealing valve at an outlet of the reaction air of the fuel cell, 2. The fuel cell system according to claim 1, wherein the circulation system of the hydrogen system, the hydrogen purge valve, and at least the outlet side sealing valve of the reaction air system are disposed in the downstream space.

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