Fuel cell system

Abstract

Noise reduction measures will be implemented to suppress turbulence generated downstream of the bypass valve in the fuel cell system and reduce noise. [Solution] The fuel cell system 10 includes a bypass channel 98 that bypasses the fuel cell stack 12 and connects a cathode gas supply channel 82 and a cathode off gas discharge channel 94, and a bypass valve 100 provided in the bypass channel 98 and including a valve body 106 that adjusts the gas flow rate by rotating. The fuel cell system 10 further includes a first rectifier plate 120 provided downstream of the valve body 106 in the bypass channel 98 and extending along the extending direction of the bypass channel 98, including a first proximal end 120A that is close to the outer edge 106A of the valve body 106 at a predetermined rotation angle.

Description

[Technical Field]

[0001] The present invention relates to a fuel cell system. [Background Art]

[0002] In recent years, research and development have been conducted on fuel cells that contribute to energy efficiency in order to enable more people to secure access to affordable, reliable, sustainable and advanced energy. As a fuel cell system, in order to dilute anode off-gas and cathode off-gas discharged from a fuel cell stack, there is known a fuel cell system that includes a bypass flow path that bypasses the fuel cell stack and connects a cathode gas supply flow path and a cathode off-gas discharge flow path, and a bypass valve that adjusts the flow rate of gas flowing through the bypass flow path (for example, Patent Document 1). [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2006-32151 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] When the bypass valve is configured as a butterfly valve including a valve body that adjusts the gas flow rate through rotation, turbulent flow occurs on the downstream side of the valve body, which causes noise generation. In particular, when the gas passing through the bypass valve is compressed air and the rotation angle of the valve body is small, a large differential pressure is generated between the upstream side and the downstream side of the valve body, and strong turbulent flow occurs on the downstream side of the valve body. This turbulent flow generates noise.

[0005] In view of the above background, an object of the present invention is to implement noise countermeasures that suppress the generation of turbulent flow occurring on the downstream side of the bypass valve and reduce noise, which ultimately contributes to improvement of energy efficiency. [Means for Solving the Problem]

[0006] To solve the above problems, one aspect of the present invention provides a fuel cell system comprising: a fuel cell stack; a cathode gas supply channel connected to the fuel cell stack; a cathode off-gas discharge channel connected to the fuel cell stack; a bypass channel that bypasses the fuel cell stack and connects the cathode gas supply channel and the cathode off-gas discharge channel; and a bypass valve provided in the bypass channel and including a valve body that adjusts the gas flow rate by rotation, further comprising a first flow-rectifying plate-like portion provided downstream of the valve body in the bypass channel and extending along the direction of extension of the bypass, including a first proximal end that is close to the outer edge of the valve body at a predetermined rotation angle. [Effects of the Invention]

[0007] According to the above embodiment, the generation of turbulence downstream of the valve body is suppressed, and noise reduction measures are taken to reduce noise. [Brief explanation of the drawing]

[0008] [Figure 1] Configuration diagram of the fuel cell system according to this embodiment [Figure 2] Longitudinal cross-sectional view of the main part of the fuel cell system according to this embodiment. [Figure 3] Half-section perspective view of the main part of the fuel cell system according to this embodiment [Figure 4] Cross-sectional view along line IV-IV in Figure 2 [Figure 5] Diagram illustrating the main components of a fuel cell system according to another embodiment. [Figure 6] Diagram illustrating the main components of a fuel cell system according to another embodiment. [Modes for carrying out the invention]

[0009] An embodiment of the fuel cell system 10 according to the present invention will be described below with reference to the figures.

[0010] As shown in Figure 1, the fuel cell system 10 includes a fuel cell stack 12, a fuel gas supply device 14 that supplies fuel gas (anode gas) to the fuel cell stack 12, an oxidant gas supply device 16 that supplies oxidant gas (cathode gas) to the fuel cell stack 12, and a cooling device 18 that cools the fuel cell stack 12. In this embodiment, the fuel gas is hydrogen gas and the oxidant gas is air.

[0011] The fuel cell stack 12 has a plurality of power generation cells 20 stacked on top of each other. Each power generation cell 20 has a plate-shaped electrolyte membrane / electrode structure 22, a first separator 24 positioned on one side of the electrolyte membrane / electrode structure 22, and a second separator 26 positioned on the other side of the electrolyte membrane / electrode structure 22. The first separator 24 and the second separator 26 may be formed from metal or carbon.

[0012] The electrolyte membrane / electrode structure 22 is composed of a laminate having a solid polymer electrolyte membrane 23 and an anode electrode 25 (fuel electrode) and a cathode electrode 27 (air electrode) arranged to sandwich the solid polymer electrolyte membrane 23 from both sides. The solid polymer electrolyte membrane 23 may be a thin film of a fluorine-based electrolyte such as perfluorosulfonic acid containing water, or a thin film of a hydrocarbon-based electrolyte.

[0013] In the fuel cell system 10, power is extracted from the anode electrode 25 and the cathode electrode 27.

[0014] An anode gas supply section 32 is formed between the first separator 24 and the electrolyte membrane / electrode structure 22 for supplying hydrogen gas, which is the anode gas, to the anode electrode 25. A cathode gas supply section 34 is formed between the second separator 26 and the electrolyte membrane / electrode structure 22 for supplying cathode gas to the cathode electrode 27. A refrigerant flow path 36 is formed between the first separator 24 and the second separator 26 of adjacent power generation cells 20, through which the refrigerant of the cooling device 18 circulates.

[0015] The fuel cell stack 12 has an anode gas inlet 38, an anode off-gas outlet 40, a cathode gas inlet 42, a cathode off-gas outlet 44, a refrigerant inlet 46, and a refrigerant outlet 48. The anode gas inlet 38 communicates with the gas intake side of the anode gas supply unit 32 of each power generation cell 20. The anode off-gas outlet 40 communicates with the gas discharge side of the anode gas supply unit 32 of each power generation cell 20. The cathode gas inlet 42 of each power generation cell 20 communicates with the gas intake side of the cathode gas supply unit 34 of each power generation cell 20. The cathode off-gas outlet 44 communicates with the discharge side of the cathode gas supply unit 34 of each power generation cell 20. The refrigerant inlet 46 communicates with the refrigerant intake side of the refrigerant flow path 36 of each power generation cell 20. The refrigerant outlet 48 communicates with the refrigerant discharge side of the refrigerant flow path 36 of each power generation cell 20.

[0016] The cooling device 18 includes a refrigerant supply channel 50 connected to the refrigerant inlet 46 of the fuel cell stack 12, a refrigerant discharge channel 52 connected to the refrigerant outlet 48 of the fuel cell stack 12, a refrigerant circulation pump 54, and a radiator 56 connected to the refrigerant supply channel 50 and the refrigerant discharge channel 52. The refrigerant circulation pump 54 is provided in the refrigerant supply channel 50 and circulates the refrigerant. The refrigerant supply channel 50, the refrigerant discharge channel 52, the refrigerant circulation pump 54, and the radiator 56 work together with the refrigerant channel 36 of each power generation cell 20 to form a refrigerant circulation channel. The refrigerant supply channel 50 and the refrigerant discharge channel 52 may be formed of resin pipes or rubber pipes to prevent the elution of metal ions into the refrigerant and to maintain the insulation properties of the refrigerant.

[0017] The fuel gas supply device 14 has a hydrogen tank 60 for storing high-pressure hydrogen gas. The hydrogen tank 60 is connected to the anode gas inlet 38 of the fuel cell stack 12 by an anode gas supply passage 62 (fuel gas supply passage). An injector 64 and an ejector 66 are provided in series with respect to each other in the anode gas supply passage 62. The hydrogen gas, which is the anode gas, is supplied from the hydrogen tank 60 through the injector 64 and ejector 66 to the anode gas inlet 38 of the fuel cell stack 12.

[0018] The anode off-gas outlet 40 is connected to the gas-liquid separation chamber 70 via an anode off-gas discharge flow path 68. The anode off-gas discharged from the anode off-gas outlet 40 is hydrogen gas at least part of which has been used at the anode electrode 25, and contains moisture.

[0019] The gas-liquid separation chamber 70 has a gas phase side and a liquid phase side, and separates the anode off-gas into gas and liquid. The liquid separated on the liquid phase side of the gas-liquid separation chamber 70 is discharged to a drain flow path 72. The drain flow path 72 includes a drain valve 74 and is connected to a dilution chamber 76. The gas phase side of the gas-liquid separation chamber 70 is connected to an ejector 66 via a gas flow path 80 including a one-way valve 78. The ejector 66 generates a negative pressure inside itself, thereby sucking gas (hydrogen gas) from the gas-liquid separation chamber 70. The gas flow path 80 is connected to the drain flow path 72 via a purge flow path 73 having a purge valve 71. Accordingly, when the purge valve 71 is opened, the anode off-gas after gas-liquid separation is discharged to the dilution chamber 76.

[0020] The oxidant gas supply device 16 has a cathode gas supply flow path 82 (oxidant gas supply flow path). One end of the cathode gas supply flow path 82 is provided with an air intake port 84 for taking in air, which is the oxidant gas, from the atmosphere. The other end of the cathode gas supply flow path 82 is connected to a cathode gas inlet 42 of the fuel cell stack 12. In the cathode gas supply flow path 82, an air pump 86, a temperature regulator 88, a cathode gas flow rate control valve 90, and a humidifier 92 are provided in series in this order from the air intake port 84 side. The air pump 86 is a compressor driven by a motor, and compresses and outputs compressed air that serves as the cathode gas. The temperature regulator 88 may include a heating wire-type or semiconductor-type heater, and adjusts the temperature of the compressed air output from the air pump 86. The compressed air output from the air pump 86 passes through the temperature regulator 88, the cathode gas flow rate control valve 90, and the humidifier 92, and is supplied to the cathode gas inlet 42 of the fuel cell stack 12.

[0021] A cathode off-gas discharge passage 94 is connected to a cathode off-gas outlet 44 of the fuel cell stack 12. The cathode off-gas discharged from the cathode off-gas outlet 44 is compressed air at least part of which has been used at the cathode electrode 27. In the cathode off-gas discharge passage 94, a humidifier 92, an off-gas flow control valve 96, and a dilution chamber 76 are provided in this order from the cathode off-gas outlet 44 side. The cathode off-gas discharge passage 94 discharges cathode off-gas from the fuel cell stack 12 to the outside of the fuel cell stack 12 via the dilution chamber 76.

[0022] The humidifier 92 is of a membrane permeation type using a hollow fiber membrane, and has a compressed air passage (not illustrated) and a cathode off-gas discharge passage (not illustrated) that are separated by the hollow fiber membrane. The humidifier 92 exchanges moisture and heat between the compressed air supplied from an air pump 86 and the cathode off-gas discharged from the fuel cell stack 12. The cathode off-gas discharged from the fuel cell stack 12 has a higher temperature and higher humidity than the compressed air in the cathode gas supply passage 82. Therefore, the temperature and humidity of the compressed air supplied from the air pump 86 increase in the humidifier 92.

[0023] A portion of the cathode gas supply passage 82 between a temperature regulator 88 and the humidifier 92, and a portion of the cathode off-gas discharge passage 94 downstream of the off-gas flow control valve 96 (the dilution chamber 76 in the present embodiment) are connected to each other via a bypass passage 98. Thereby, the bypass passage 98 bypasses the fuel cell stack 12 and connects the cathode gas supply passage 82 and the cathode off-gas discharge passage 94. A bypass valve 100 is provided in the bypass passage 98.

[0024] In the dilution chamber 76, anode off-gas discharged from a drain passage 72 is diluted by cathode off-gas from the cathode off-gas discharge passage 94 or compressed air from the bypass passage 98.

[0025] Details of the dilution chamber 76, the bypass passage 98, and the bypass valve 100 will be described with reference to FIGS. 2 to 4.

[0026] The bypass valve 100 has a valve housing 104 equipped with a valve chamber 102 having a cylindrical, or in other words, circular, cross-sectional shape. The valve chamber 102 forms part of the bypass flow path 98 and allows compressed air to flow from left to right in Figures 2 and 3. The valve chamber 102 houses a disc-shaped valve body 106. The valve housing 104 rotatably supports the valve body 106 by a shaft 108. Thus, the bypass valve 100 constitutes a butterfly valve that quantitatively adjusts the gas flow rate (compressed air flow rate) of the bypass flow path 98 by the rotation of the valve body 106. An electric motor 110 (see Figure 3) that rotates the valve body 106 is attached to the valve housing 104 via the shaft 108.

[0027] A flanged cylindrical outlet port member 114 is attached to the right side wall of the valve housing 104, defining an outlet port 112 that communicates with the valve chamber 102. The inner diameter of the outlet port 112 may be approximately the same as the inner diameter of the valve chamber 102.

[0028] One end 116A of a cylindrical joint pipe 116 is inserted into the outlet port 112. The other end 116B of the joint pipe 116 is inserted into the inlet port 79 of the dilution chamber housing 77 that defines the dilution chamber 76 and protrudes into the dilution chamber 76. The joint pipe 116 has a pipe passage 118 that forms part of the bypass passage 98, which connects the valve chamber 102 and the dilution chamber 76. In other words, the pipe passage 118 forms part of the bypass passage 98 downstream of the valve chamber 102.

[0029] The inner diameter of the pipe passage 118 is smaller than the inner diameters of the valve chamber 102 and the outlet port 112. The pipe passage 118 gradually expands in diameter towards the outlet port 112 to the same diameter as the inner diameters of the valve chamber 102 and the outlet port 112, and includes an insertion end 116C that is close to the valve chamber 102 and the outlet port 112. As a result, the pipe passage 118 and the valve chamber 102 and the outlet port 112 are smoothly connected without any steps at their connection point.

[0030] A first rectifier plate 120 (first rectifier plate-shaped part) is provided downstream of the valve body 106. The first rectifier plate 120 is located inside the joint pipe 116, that is, in the pipe flow path 118, and is fixed to the joint pipe 116.

[0031] The first rectifier plate 120 is positioned on the side where its outer edge 106A is displaced downstream of the pipe flow path 118 when the valve body 106 opens from the fully closed position. The first rectifier plate 120 includes a first proximal end 120A that is close to the outer edge 106A of the valve body 106 when it is positioned at a relatively small predetermined rotation angle, and extends along the extending direction of the pipe flow path 118 to the vicinity of the other end 116B of the joint pipe 116. When the valve body 106 is positioned at the predetermined rotation angle, the pipe flow path 118 is divided into a primary flow path 118A and a secondary flow path 118B by the first rectifier plate 120.

[0032] The bypass valve 100 is fully closed when the fuel cell stack 12 is operating at full load and the cathode gas flow control valve 90 is fully open, and is partially open when the valve body 106 is positioned at the predetermined rotation angle described above during most other partial load operations.

[0033] The first proximal end 120A of the first rectifier plate 120 has a curved cross-section that follows the outer edge 106A of the valve body 106 when the valve body 106 is positioned at the predetermined rotation angle (see Figure 4). The first proximal end 120A may include a portion that enters the valve chamber 102. The curved cross-sectional shape of the first rectifier plate 120 may be the same from the first proximal end 120A to the first distal end 120B on the other end 116B side of the joint pipe 116.

[0034] The first rectifier plate 120 is positioned close to the side of the pipe flow path 118 where its outer edge 106A is displaced downstream when the valve body 106 opens from the fully closed position. In other words, the first rectifier plate 120 is positioned in a location where turbulence is likely to occur. This effectively suppresses the generation of turbulence by the first rectifier plate 120.

[0035] In this embodiment, as shown in Figures 2 and 3, when the valve body 106 is at a predetermined rotation angle that is relatively small, the first proximal end 120A of the first rectifier plate 120 is close to the outer edge 106A of the valve body 106. Therefore, when the valve body 106 is at the predetermined rotation angle, the pipe flow path 118 downstream of the valve body 106 is clearly divided into a primary flow path 118A and a secondary flow path 118B, and the compressed air flows separately into the primary flow path 118A and the secondary flow path 118B. In other words, the movement of compressed air that would otherwise generate strong turbulence, particularly in the secondary flow path 118B, is interrupted by the first rectifier plate 120, which provides good rectification in each flow path. As a result, the generation of turbulence in the pipe flow path 118 is effectively suppressed, and the generation of noise originating from the joint pipe 116 is effectively suppressed.

[0036] Because the first rectifier plate 120 has a curved cross-section that follows the outer edge 106A of the valve body 106, the compressed air flows smoothly from the valve chamber 102 to the primary flow path 118A and the secondary flow path 118B. Therefore, noise generation is more effectively suppressed.

[0037] Furthermore, because the pipe passage 118, valve chamber 102, and outlet port 112 are smoothly connected without any steps, turbulence in the flow of compressed air from the valve chamber 102 and outlet port 112 to the pipe passage 118 is suppressed. As a result, the generation of noise and vibration caused by turbulence in the airflow in the pipe passage 118 is suppressed.

[0038] Figure 5 shows an overview of the main parts of another embodiment of the fuel cell system 10. In Figure 5, parts corresponding to Figures 1 to 4 are given the same reference numerals as those used in Figures 1 to 4, and their descriptions are omitted.

[0039] In this embodiment, in addition to the first rectifier plate 120, a second rectifier plate 122 (second rectifying plate-shaped portion) is provided upstream of the valve body 106 located in the bypass flow path 98. The second rectifier plate 122 extends along the direction of extension of the bypass flow path 98, including a second proximal end 122A that is close to the outer edge 106A of the valve body 106 located at the predetermined rotation angle described above.

[0040] The bypass flow path 98 upstream of the valve body 106 is divided into a primary flow path 124A and a secondary flow path 124B by the second rectifier plate 122 when the valve body 106 is in the predetermined rotation angle described above.

[0041] The first rectifier plate 120 is formed such that the cross-sectional area of ​​the secondary flow channel 118B gradually increases as the first distal end 120B moves downstream. The second rectifier plate 122 is formed such that the cross-sectional area of ​​the secondary flow channel 124B gradually increases as the second distal end 122B moves upstream.

[0042] In this embodiment, the provision of the second rectifier plate 122 suppresses turbulence in the airflow in the bypass passage 98 upstream of the valve body 106.

[0043] Furthermore, the first distal end 120B of the first rectifier plate 120 is formed such that the cross-sectional area of ​​the secondary flow channel 118B gradually increases as it moves downstream, and the second distal end 122B of the second rectifier plate 122 is formed such that the cross-sectional area of ​​the secondary flow channel 124B gradually increases as it moves upstream. These features provide an effective rectifying effect, effectively suppressing the generation of turbulence in the bypass flow channel 98.

[0044] Although the present invention has been described above in terms of preferred embodiments, as will be easily understood by those skilled in the art, the present invention is not limited to these embodiments and can be modified as appropriate without departing from the spirit of the invention.

[0045] For example, the cross-sectional shape of the first rectifier plate 120 may have a curved cross-sectional shape at the first proximal end 120A that follows the outer edge 106A of the valve body 106 located at a predetermined rotation angle, and the cross-sectional shape may gradually become straighter as it approaches the first distal end 120B. The first rectifier plate 120 may be composed of a plurality of parallel plate materials to correspond to valve bodies 106 at different rotation angles. The valve body 106 may be composed of a flapper valve, as shown in Figure 6.

[0046] The above embodiments may also be described as follows:

[0047] One embodiment is a fuel cell system comprising a fuel cell stack 12, a cathode gas supply channel 82 connected to the fuel cell stack 12, a cathode off-gas discharge channel 94 connected to the fuel cell stack 12, a bypass channel 98 that bypasses the fuel cell stack 12 and connects the cathode gas supply channel 82 and the cathode off-gas discharge channel 94, and a bypass valve 100 provided in the bypass channel 98 and including a valve body 106 that adjusts the gas flow rate by rotation, further comprising a first rectifier plate 120 (first rectifier plate-shaped portion) provided downstream of the valve body 106 in the bypass channel 98 and extending along the extending direction of the bypass channel 98, including a first proximal end 120A that is close to the outer edge 106A of the valve body 106 at a predetermined rotation angle.

[0048] With this configuration, the first rectifier plate 120 suppresses the generation of turbulence downstream of the valve body 106.

[0049] In the above embodiment, the bypass valve 100 is composed of a butterfly valve, the valve body 106 is disc-shaped, and the first rectifier plate 120 may be provided on the side where the outer edge 106A is displaced downstream of the bypass flow path 98 when the valve body 106 opens from the fully closed position.

[0050] With this configuration, the first rectifier plate 120 is provided in locations where turbulence is likely to occur, effectively suppressing the generation of turbulence.

[0051] In the above embodiment, the bypass flow path 98 may be divided into a primary flow path 118A and a secondary flow path 118B by the first rectifier plate 120 when the valve body 106 is in the position of the predetermined rotation angle.

[0052] With this configuration, turbulence is effectively suppressed downstream of the valve body 106 while maintaining good flow straightening.

[0053] In the above embodiment, the first rectifier plate 120 may have a cross-section that is curved to follow the outer edge 106A of the valve body 106.

[0054] With this configuration, turbulence is effectively suppressed downstream of the valve body 106 while maintaining good flow straightening.

[0055] In the above embodiment, the bypass valve 100 includes a valve housing 104 that includes a cylindrical valve chamber 102 housing the valve body 106 and rotatably supports the valve body 106 by a shaft 108, and an outlet port member 114 attached to the valve housing 104 that defines an outlet port 112 communicating with the valve chamber 102, wherein a cylindrical joint pipe 116 defining a part of the bypass flow path 98 is inserted into the outlet port 112, and the first rectifier plate 120 may be arranged inside the joint pipe 116.

[0056] This configuration effectively suppresses the generation of turbulence inside the joint pipe 116.

[0057] In the above embodiment, the joint pipe 116 may include an insertion end 116C that is close to the valve chamber 102 so that the bypass passage 98 is smoothly connected to the valve chamber 102 without any step between it and the valve chamber 102.

[0058] This configuration suppresses the generation of turbulence at the connection point between the valve chamber 102 and the bypass flow path 98.

[0059] In the above embodiment, the bypass flow path 98 may further have a second rectifier plate 122 (second rectifier plate-shaped portion) provided on the upstream side of the valve body 106, and extending along the extending direction of the bypass flow path 98, including a second proximal end 122A that is close to the outer edge 106A of the valve body 106 located at the predetermined rotation angle.

[0060] This configuration suppresses the generation of turbulence upstream of the valve body 106.

[0061] Furthermore, not all of the components shown in the above embodiments are necessarily essential, and they can be appropriately selected and omitted as long as they do not deviate from the spirit of the present invention. [Explanation of symbols]

[0062] 10: Fuel cell system 12: Fuel cell stack 82: Cathode gas supply channel 94: Cathode-off gas discharge channel 98: Bypass channel 100: Bypass valve 102: Valve chamber 104: Valve Housing 106: Valve body 106A: Outer edge 108: Axis 112: Exit Port 112A: Second proximal end 114: Outlet port member 114B: Secondary channel 116: Joint pipe 116C: Insertion end 118A: Primary channel 118B: Secondary channel 120: First rectifier plate (first rectifier plate-shaped part) 120A: First proximal end 122: Second rectifier plate (second rectifier plate-shaped part) 122A: Second proximal end 124A: Primary channel 124B: Secondary channel

Claims

1. Fuel cell stack and A cathode gas supply channel connected to the fuel cell stack, A cathode-off gas discharge channel connected to the fuel cell stack, A bypass channel that bypasses the fuel cell stack and connects the cathode gas supply channel and the cathode off-gas discharge channel, A fuel cell system comprising a bypass valve provided in the bypass flow path and including a valve body that adjusts the gas flow rate by rotation, The bypass flow path is provided downstream of the valve body and further includes a first flow-rectifying plate-like portion that extends along the direction of extension of the bypass flow path, including a first proximal end that is close to the outer edge of the valve body at a predetermined rotation angle, The bypass valve is composed of a butterfly valve, and the valve body is disc-shaped. The first flow-rectifying plate-shaped portion is provided on the side where the outer edge is displaced downstream of the bypass flow path when the valve body opens from the fully closed position. When the valve body is positioned at the predetermined rotation angle, the bypass passage is divided into a primary passage and a secondary passage by the first rectifying plate-shaped portion. A fuel cell system in which the edge of the first rectifying plate-shaped portion on the valve body side has a cross-sectional shape that is curved along the ellipse, so as viewed from the extending direction of the bypass flow path, when the valve body is positioned at the predetermined rotation angle, the ellipse is aligned with the outer edge of the valve body.

2. The bypass valve includes a valve housing that includes a cylindrical valve chamber for housing the valve body and rotatably supports the valve body by a shaft, and an outlet port member attached to the valve housing that defines an outlet port communicating with the valve chamber, A cylindrical joint pipe is inserted into the outlet port, defining a portion of the bypass flow path. The fuel cell system according to claim 1, wherein the first rectifying plate-shaped portion is arranged inside the joint pipe.

3. The fuel cell system according to claim 2, wherein the joint pipe includes an insertion end adjacent to the valve chamber so that the bypass flow path is smoothly connected to the valve chamber without any step between it and the valve chamber.

4. The fuel cell system according to claim 1, further comprising a second flow-rectifying plate-like portion provided on the upstream side of the valve body in the bypass flow path, and extending along the direction of extension of the bypass flow path, including a second proximal end adjacent to the outer edge of the valve body located at the predetermined rotation angle.

Images