Diluter

Abstract

To provide a diluter capable of suppressing noise generation.SOLUTION: Each of a retention chamber 60 and a dilution chamber 61 of a diluter 30 has a portion extending from the first end toward the second end in the first direction X and aligned in the second direction Y with a partition wall 40 interposed therebetween. An anode off-gas inlet 50 is arranged at the first end in the first direction X in the retention chamber 60. A communication port 62 is arranged at a position closer to the second end in the first direction X than an intermediate position P in the first direction X. The communication port 62 is formed with the inner surface of a container 31 facing in the vertical direction Z as a part of the defining surface of the communication port 62.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a diluter that dilutes anode off-gas with cathode off-gas and discharges the diluted anode off-gas. [Background technology]

[0002] The fuel cell system includes a diluter that dilutes the anode off-gas discharged from the fuel cell with the cathode off-gas discharged from the fuel cell and discharges the diluted anode off-gas into the atmosphere. The diluter includes a container. A retention chamber and a dilution chamber are defined inside the container. Anode off-gas discharged from the fuel cell flows into the retention chamber. Water contained in the anode off-gas is separated from the anode off-gas in the retention chamber and accumulates in the retention chamber.

[0003] The cathode off-gas discharged from the fuel cell flows into the dilution chamber. A portion of the anode off-gas that is retained in the retention chamber flows into the dilution chamber. In the dilution chamber, the cathode off-gas is mixed with the anode off-gas. The anode off-gas diluted in the dilution chamber is discharged outside the dilution chamber.

[0004] Various noises are generated from the diluter due to abrupt changes in the flow of the anode off-gas inside the diluter, water being entrained in the anode off-gas, etc. In order to reduce noise leaking to the outside of the diluter, Patent Document 1 discloses that at least a part of the housing of the diluter is made of a laminated member formed by pressing a plurality of metal plates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-272090 A Summary of the Invention [Problem to be solved by the invention]

[0006] The diluter of Patent Document 1 increases the number of parts and increases the manufacturing cost of the diluter in order to reduce the noise leaking outside the diluter. Therefore, there is a demand for a diluter that suppresses the generation of noise itself without increasing the number of parts and the manufacturing cost of the diluter. [Means for solving the problem]

[0007] A diluter for solving the above problems includes a container that defines an internal space, a partition wall that divides the internal space into a retention chamber and a dilution chamber, an anode offgas inlet provided in the container for allowing anode offgas discharged from a fuel cell to flow into the retention chamber, a cathode offgas inlet provided in the container for allowing cathode offgas discharged from the fuel cell to flow into the dilution chamber, and a communication port that communicates the retention chamber and the dilution chamber inside the container, and the diluter dilutes the anode offgas with the cathode offgas, and the diluter has a first direction along a horizontal plane, the first direction being the longitudinal direction of the container, and a second direction along the horizontal plane being the longitudinal direction of the container. The gist of the invention is that, when a direction perpendicular to the first direction is defined as a second direction, each of the residence chamber and the dilution chamber has a portion extending from a first end to a second end in the first direction and aligned in the second direction across the partition wall, the anode off-gas inlet is disposed at the first end of the residence chamber in the first direction, and when a position that divides the residence chamber in half in the first direction is defined as a midpoint of the residence chamber, the communication port is disposed at a position in the first direction closer to the second end in the first direction than the midpoint, and the communication port is formed with the inner surface of the container facing in the vertical direction as part of a boundary surface of the communication port.

[0008] The anode off-gas that flows into the retention chamber from the anode off-gas inlet flows in the retention chamber in the first direction toward the communication port without changing the flow direction significantly. As a result, the anode off-gas that flows into the retention chamber can be prevented from changing the flow direction abruptly. Therefore, the diluter can prevent the generation of noise caused by the abrupt change in the flow direction. In addition, the water separated from the anode off-gas accumulates in the retention chamber. The communication port is formed with the inner surface of the container facing in the vertical direction as a part of the boundary surface of the communication port. In other words, the communication port is open over the entire vertical dimension of the container. Therefore, the anode off-gas that flows out to the dilution chamber via the communication port passes above the communication port, and the water passes below the communication port. In other words, the anode off-gas and the water pass through the communication port while being separated into upper and lower parts. Therefore, it is possible to prevent the water from being mixed into the anode off-gas near the communication port. As a result, the diluter can suppress the generation of noise caused by water being entrained in the anode off-gas, and therefore the diluter can suppress the generation of noise itself without increasing the number of parts of the diluter and the manufacturing costs.

[0009] With regard to the diluter, an anode off-gas exhaust passage connected to the fuel cell is connected to the anode off-gas inlet, and an exhaust valve is provided in the anode off-gas exhaust passage, and when the amount of the anode off-gas flowing from the anode off-gas exhaust passage through the anode off-gas inlet into the retention chamber when the exhaust valve is opened once is defined as a discharge amount, the volume of the retention chamber may be larger than the discharge amount.

[0010] According to this, when anode off-gas flows into the retention chamber, the anode off-gas retained in the retention chamber is pushed out of the retention chamber via the communication port at a volume corresponding to the discharge amount. The larger the volume of the retention chamber is, the slower the flow speed of the anode off-gas pushed out of the communication port is. When the anode off-gas passes through the communication port, wind noise is generated. This wind noise becomes smaller as the flow speed of the anode off-gas pushed out of the communication port is slowed. Therefore, making the volume of the retention chamber larger than the discharge amount reduces the wind noise.

[0011] Regarding the diluter, the container has a bottom plate and a top plate that face each other in the vertical direction, and the inner surfaces of the container that face each other in the vertical direction are an inner bottom surface of the container formed by the bottom plate and a ceiling surface of the container formed by the top plate, and the anode off-gas inlet may be spaced above the inner bottom surface of the container.

[0012] With this, when the anode off-gas flows into the retention chamber from the anode off-gas inlet, the water accumulated on the inner bottom surface can be prevented from being mixed with the anode off-gas, thereby preventing noise caused by water being mixed with the anode off-gas.

[0013] Regarding the diluter, if the direction in which the anode off-gas flows from the residence chamber to the dilution chamber via the communication port is defined as the outflow direction, the cathode off-gas inlet may be positioned in a position that does not face the communication port in the outflow direction.

[0014] This makes it possible to prevent collision between the anode off-gas flowing out from the retention chamber to the dilution chamber via the communication port and the cathode off-gas flowing into the dilution chamber from the cathode off-gas inlet, thereby making it possible for the diluter to prevent noise caused by collision between the anode off-gas and the cathode off-gas.

[0015] Regarding the dilution device, the opening area of ​​the communication port is 650 mm per 1 liter of the volume of the retention chamber. 2 It may be set to more than this. According to this, when anode off-gas flows into the retention chamber, the anode off-gas retained in the retention chamber is pushed out through the communication port. The larger the opening area of ​​the communication port, the slower the flow rate of the anode off-gas pushed out through the communication port. When the anode off-gas passes through the communication port, wind noise is generated. This wind noise becomes smaller as the flow rate of the anode off-gas pushed out through the communication port is slowed. Therefore, the air pressure of 650 mm per liter of retention chamber volume is 100 MPa. 2Setting it higher will reduce wind noise. Effect of the Invention

[0016] The present invention can suppress the generation of noise. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram showing a fuel cell system. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a perspective view showing the inside of the diluter. [Figure 4] 4 is a cross-sectional view taken along line 4-4 in FIG. 2, showing the inside of the diluter. [Diagram 5] 5 is a cross-sectional view taken along line 5-5 in FIG. 2, showing the inside of the diluter. [Figure 6] 6 is a cross-sectional view taken along line 6-6 in FIG. 2, showing the inside of the diluter. [Figure 7] 13A and 13B are diagrams showing another example of a communication port. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, one embodiment of the diluter will be described with reference to Figs. <Overall configuration of fuel cell system> 1, the fuel cell system 10 includes a fuel cell stack 11, a hydrogen tank 12, an air compressor 13, a gas-liquid separator 14, a drain tank 15, and a diluter 30. The fuel cell system 10 also includes an anode gas supply path 16, a cathode gas supply path 17, a first discharge path 18, a second discharge path 19, a drain path 21, a cathode off-gas discharge path 22, an anode gas circulation path 23, a gas discharge path 25, and an exhaust valve 24.

[0019] <Fuel cell stack> The fuel cell stack 11 is a fuel cell formed by stacking a plurality of fuel cells. The fuel cells are solid molecular fuel cells. The fuel cell stack 11 generates power by being supplied with hydrogen gas as the anode gas and an oxidant gas as the cathode gas. The oxidant gas is air.

[0020] <Hydrogen tank, air compressor, gas-liquid separator, wastewater tank> The hydrogen tank 12 stores hydrogen gas. The air compressor 13 compresses air. The gas-liquid separator 14 separates water contained in the anode off-gas discharged from the fuel cell stack 11 from the anode off-gas. The drainage tank 15 stores the water separated from the anode off-gas and the cathode off-gas. The diluter 30 will be described in detail later.

[0021] <Anode gas supply line> The anode gas supply passage 16 connects an anode (not shown) of the fuel cell stack 11 to the hydrogen tank 12. The anode gas stored in the hydrogen tank 12 flows through the anode gas supply passage 16 from the hydrogen tank 12 toward the fuel cell stack 11.

[0022] <Cathode gas supply path> The cathode gas supply passage 17 connects a cathode (not shown) of the fuel cell stack 11 to the air compressor 13. Air compressed by the air compressor 13 is supplied to the cathode gas supply passage 17. The air compressed by the air compressor 13 flows through the cathode gas supply passage 17 from the air compressor 13 toward the fuel cell stack 11.

[0023] <1st discharge path> The first discharge path 18 connects an anode (not shown) of the fuel cell stack 11 to the gas-liquid separator 14. Anode off-gas discharged from the anode of the fuel cell stack 11 flows through the first discharge path 18 from the anode of the fuel cell stack 11 toward the gas-liquid separator 14. The anode off-gas mainly contains unreacted hydrogen gas in the fuel cell stack 11 and water produced when hydrogen reacts with oxygen.

[0024] <Second discharge path> The second discharge path 19 connects the gas-liquid separator 14 and the diluter 30. The first discharge path 18, the gas-liquid separator 14, and the second discharge path 19 constitute an anode off-gas discharge path 20 that connects the fuel cell stack 11 and the diluter 30.

[0025] The anode off-gas discharged from the gas-liquid separator 14 flows through the second discharge path 19 from the gas-liquid separator 14 toward the diluter 30. Therefore, the anode off-gas is discharged from the outlet of the second discharge path 19, which is the outlet of the anode off-gas discharge path 20. Note that water that could not be separated from the anode off-gas by the gas-liquid separator 14 flows through the second discharge path 19.

[0026] <Gas exhaust passage> The gas exhaust passage 25 is connected to a diluter 30 . <Exhaust valve> The exhaust valve 24 is provided in the anode off-gas discharge passage 20. Specifically, the exhaust valve 24 is provided in the second discharge passage 19 of the anode off-gas discharge passage 20. The exhaust valve 24 opens and closes the second discharge passage 19, which is a part of the anode off-gas discharge passage 20. The exhaust valve 24 is normally closed, but is instantaneously opened when a predetermined amount of anode off-gas is stored in the gas-liquid separator 14. When the exhaust valve 24 is opened once, the anode off-gas is discharged from the gas-liquid separator 14. The amount of anode off-gas discharged when the exhaust valve 24 is opened once is defined as the discharge amount. The discharge amount can be calculated from the volume of the fuel cell stack 11 and the pressure difference of the fuel cell stack 11 before and after the exhaust valve 24 is opened. The maximum value of the discharge amount of the anode off-gas is confirmed in advance by an experiment or the like. As an example, the maximum value of the discharge amount of the anode off-gas is determined by the maximum pressure of the anode off-gas within the operating range of the fuel cell system 10 and the maximum open time of the exhaust valve 24. The volume of the fuel cell stack 11 is calculated by multiplying the volume of each fuel cell by the number of fuel cells.

[0027] <Drainage channel> The drainage channel 21 connects the diluter 30 and the drainage tank 15. The water discharged from the diluter 30 flows through the drainage channel 21. In addition, the anode gas discharged from the gas-liquid separator 14 flows from the anode gas circulation channel 23 toward the anode gas supply channel 16.

[0028] <Cathode off-gas exhaust passage> The cathode offgas discharge path 22 connects a cathode (not shown) of the fuel cell stack 11 to the diluter 30. The cathode offgas flows through the cathode offgas discharge path 22 from the fuel cell stack 11 toward the diluter 30. The cathode offgas mainly contains air containing unreacted oxygen in the fuel cell stack 11 and water produced when hydrogen and oxygen react with each other.

[0029] <Diluter> The anode off-gas discharged from the fuel cell stack 11 flows into the diluter 30. In detail, the anode off-gas flows into the diluter 30 via the first discharge path 18, the gas-liquid separator 14, and the second discharge path 19. In addition, the cathode off-gas discharged from the fuel cell stack 11 flows into the diluter 30. The diluter 30 discharges exhaust gas obtained by diluting a portion of the anode off-gas that has flowed into the diluter 30 with the cathode off-gas. The exhaust gas is a mixture of the anode off-gas and the cathode off-gas.

[0030] As shown in Figs. 2 to 6, the diluter 30 has a container 31 and a partition wall 40 that divides the internal space S of the container 31. The partition wall 40 divides the internal space S of the container 31 into two chambers, a retention chamber 60 and a dilution chamber 61. The diluter 30 also has a communication port 62. The communication port 62 communicates between the retention chamber 60 and the dilution chamber 61.

[0031] Assuming that the diluter 30 is placed on a horizontal plane, the direction of gravity is indicated by the Z axis, and the two directions along the horizontal plane are indicated by the X axis and the Y axis. The X axis, Y axis, and Z axis are perpendicular to each other. In the following description, the direction parallel to the Z axis is also referred to as the vertical direction Z, and the direction parallel to the X axis is also referred to as the first direction X. The direction parallel to the Y axis is also referred to as the second direction Y. Therefore, the second direction Y is a direction perpendicular to both the first direction X and the vertical direction Z.

[0032] <Container> As shown in FIG. 2 and FIG. 3, the container 31 is a rectangular parallelepiped whose longitudinal direction extends in the first direction X. The longitudinal direction of the container 31 coincides with the first direction X. A line extending virtually in a straight line in the longitudinal direction of the container 31 is defined as a first virtual line L1. A line extending virtually in a straight line in the lateral direction of the container 31 is defined as a second virtual line L2. On a horizontal plane, the first virtual line L1 and the second virtual line L2 are perpendicular to each other. The first virtual line L1 of the container 31 extends in the first direction X, that is, in the longitudinal direction of the container 31. Therefore, the first direction X is a direction along the horizontal plane, and can be said to be the longitudinal direction of the container 31. The second virtual line L2 of the container 31 extends in the second direction Y, that is, in the lateral direction of the container 31. Therefore, the second direction Y is one of the directions along the horizontal plane, and can be said to be a direction perpendicular to the first direction X.

[0033] 2 to 6, the container 31 has a bottom plate 32 and a top plate 33 facing each other in the vertical direction Z. The bottom plate 32 and the top plate 33 are each shaped like a rectangular plate. The long edges of the bottom plate 32 and the top plate 33 extend in the first direction X. The short edges of the bottom plate 32 and the top plate 33 extend in the second direction Y. The distance between the bottom plate 32 and the top plate 33 in the vertical direction Z may be constant in the first direction X and the second direction Y, or may change from one end to the other end in at least one of the first direction X and the second direction Y.

[0034] The bottom plate 32 has an inner bottom surface 32a on one side in the plate thickness direction, and an outer bottom surface 32b on the other side in the plate thickness direction. The plate thickness direction of the bottom plate 32 coincides with the vertical direction Z. The top plate 33 has a ceiling surface 33a on one side in the plate thickness direction, and an outer end surface 33b on the other side in the plate thickness direction. The plate thickness direction of the top plate 33 coincides with the vertical direction Z. The inner bottom surface 32a of the bottom plate 32 and the ceiling surface 33a of the top plate 33 face each other in the vertical direction Z. In other words, the inner surface of the container 31 facing the vertical direction Z is the inner bottom surface 32a of the container 31 formed by the bottom plate 32, and the ceiling surface 33a of the container 31 formed by the top plate 33.

[0035] The container 31 has a first side plate 34 and a second side plate 35 facing each other in the second direction Y. Each of the first side plate 34 and the second side plate 35 is a rectangular plate. The long edges of the first side plate 34 and the second side plate 35 extend in the first direction X. The short edges of the first side plate 34 and the second side plate 35 extend in the vertical direction Z. The first side plate 34 has an inner surface 34a on one side in the plate thickness direction and an outer surface 34b on the other side in the plate thickness direction. The plate thickness direction of the first side plate 34 coincides with the second direction Y. The second side plate 35 has an inner surface 35a on one side in the plate thickness direction and an outer surface 35b on the other side in the plate thickness direction. The plate thickness direction of the second side plate 35 coincides with the second direction Y.

[0036] The container 31 has a first end plate 36 and a second end plate 37 facing each other in a first direction X. The first end plate 36 and the second end plate 37 are rectangular plates. The long edges of the first end plate 36 and the second end plate 37 extend in the second direction Y. The short edges of the first end plate 36 and the second end plate 37 extend in the vertical direction Z. The first end plate 36 has an inner surface 36a on one side in the thickness direction and an outer surface 36b on the other side in the thickness direction. The thickness direction of the first end plate 36 coincides with the first direction X. The second end plate 37 has an inner surface 37a on one side in the thickness direction and an outer surface 37b on the other side in the thickness direction. The thickness direction of the second end plate 37 coincides with the first direction X.

[0037] The bottom plate 32, the top plate 33, the first side plate 34, the second side plate 35, the first end plate 36, and the second end plate 37 are plates that make up the container 31. The longitudinal direction of the container 31 is the direction in which the long edges of the bottom plate 32, the top plate 33, the first side plate 34, and the second side plate 35 extend.

[0038] The internal space S is defined by the inner bottom surface 32a of the bottom plate 32, the ceiling surface 33a of the top plate 33, the inner surface 34a of the first side plate 34, the inner surface 35a of the second side plate 35, the inner surface 36a of the first end plate 36, and the inner surface 37a of the second end plate 37. Thus, the container 31 defines the internal space S. The internal space S is a space that extends longitudinally in the longitudinal direction of the container 31, i.e., in the first direction X.

[0039] <Partition wall> The partition wall 40 has a first partition portion 41 and a second partition portion 42. The first partition portion 41 and the second partition portion 42 are rectangular plate-shaped. The partition wall 40 is formed by combining the first partition portion 41 and the second partition portion 42. When the partition wall 40 is viewed from the vertical direction Z, the partition wall 40 is L-shaped.

[0040] The first partition portion 41 has a first inner surface 41a on one side in the plate thickness direction and a first outer surface 41b on the other side in the plate thickness direction. The long edges of the first partition portion 41 extend in the second direction Y. The short edges of the first partition portion 41 extend in the vertical direction Z.

[0041] The first partition 41 has a first joint edge 41c at one end edge in the long edge direction and a first non-joined edge 41d at the other end edge in the long edge direction. The first joint edge 41c of the first partition 41 is joined to the inner surface 34a of the first side plate 34. The middle position in the long edge direction of the first side plate 34 is set as a first middle position P1. The first joint edge 41c of the first partition 41 is located closer to the second end plate 37 than the first middle position P1 in the first direction X. The first non-joined edge 41d of the first partition 41 is separated from the second partition 42 in the second direction Y. That is, the first non-joined edge 41d is not joined to the second partition 42. The first non-joined edge 41d faces the second partition 42 in the second direction Y.

[0042] The second partition portion 42 has a second inner surface 42a on one side in the plate thickness direction and a second outer surface 42b on the other side in the plate thickness direction. The long edge of the second partition portion 42 extends in the first direction X. The short edge of the second partition portion 42 extends in the vertical direction Z. The first non-joint edge 41d of the first partition portion 41 is separated from the second inner surface 42a of the second partition portion 42 in the second direction Y.

[0043] The second partition 42 has a second joining edge 42c at one end edge in the long edge direction and a second non-joining edge 42d at the other end edge in the long edge direction. The second joining edge 42c of the second partition 42 is joined to the inner surface 36a of the first end plate 36. The middle position in the long edge direction of the first end plate 36 is set as a second middle position P2. The second joining edge 42c of the second partition 42 is located closer to the second side plate 35 than the second middle position P2 in the second direction Y. The second non-joining edge 42d of the second partition 42 faces the inner surface 37a of the second end plate 37 in the first direction X.

[0044] The lower edges of the first partition portion 41 and the second partition portion 42 are joined to the inner bottom surface 32a of the bottom plate 32. The upper edges of the first partition portion 41 and the second partition portion 42 are joined to the ceiling surface 33a of the top plate 33.

[0045] The partition wall 40 divides the internal space S into two chambers, a retention chamber 60 and a dilution chamber 61. The retention chamber 60 is a space defined by the inner bottom surface 32a of the bottom plate 32, the ceiling surface 33a of the top plate 33, the inner surface 34a of the first side plate 34, the inner surface 36a of the first end plate 36, the first inner surface 41a of the first partition portion 41, and the second inner surface 42a of the second partition portion 42. The dilution chamber 61 is a space defined by the inner bottom surface 32a, the ceiling surface 33a, the inner surface 34a, the inner surface 35a, the inner surface 36a, the inner surface 37a, the first outer surface 41b, and the second outer surface 42b.

[0046] The retention chamber 60 is a space whose longitudinal axis extends from the first end plate 36 toward the second end plate 37. The retention chamber 60 is defined in the shape of a rectangular parallelepiped whose longitudinal axis extends in the first direction X. In the first direction X, the retention chamber 60 has a constant dimension in the second direction Y and a constant dimension in the vertical direction Z. However, the retention chamber 60 does not have to have a constant dimension in at least one of the second direction Y and the vertical direction Z.

[0047] A plane obtained by virtually extending the first partition 41 in the second direction Y is defined as a virtual plane M. The dilution chamber 61 is composed of a first chamber 61a and a second chamber 61b. The first chamber 61a is defined by the inner surface 36a of the first end plate 36, the second outer surface 42b of the second partition 42, the virtual plane M, the inner surface 35a of the second side plate 35, the inner bottom surface 32a of the bottom plate 32, and the ceiling surface 33a of the top plate 33. The second chamber 61b is defined by the virtual plane M, the first outer surface 41b of the first partition 41, the inner surface 34a of the first side plate 34, the inner surface 37a of the second end plate 37, the inner surface 35a of the second side plate 35, the inner bottom surface 32a of the bottom plate 32, and the ceiling surface 33a of the top plate 33.

[0048] The first chamber 61a has a rectangular parallelepiped shape extending longitudinally in the first direction X. The second chamber 61b has a rectangular parallelepiped shape extending longitudinally in the second direction Y. The first chamber 61a is a space aligned with the retention chamber 60 in the second direction Y across the second partition 42. Therefore, it can be said that each of the retention chamber 60 and the dilution chamber 61 has a portion that extends from the first end plate 36, which is a first end in the first direction X, toward the second end plate 37, which is a second end, and is aligned in the second direction Y across the partition wall 40.

[0049] The second chamber 61b is a space aligned with the retention chamber 60 in the first direction X across the first partition portion 41. The second chamber 61b is a space aligned with the first chamber 61a in the first direction X across an imaginary plane M. When the dilution chamber 61 is viewed in the vertical direction Z, the dilution chamber 61 is defined in an L shape.

[0050] In the first direction X, the dilution chamber 61 has a constant dimension in the second direction Y and a constant dimension in the vertical direction Z. However, the dilution chamber 61 does not have to have a constant dimension in at least one of the second direction Y and the vertical direction Z. The volume of the retention chamber 60 is smaller than the volume of the dilution chamber 61.

[0051] <Communication port> The communication port 62 communicates the retention chamber 60 and the dilution chamber 61 inside the container 31. The communication port 62 is defined between the first non-joint edge 41d, a part of the second inner surface 42a of the second partition portion 42 facing the first non-joint edge 41d in the second direction Y, the inner bottom surface 32a of the bottom plate 32, and the ceiling surface 33a of the top plate 33. Therefore, the communication port 62 is formed with the first non-joint edge 41d, a part of the second inner surface 42a of the second partition portion 42, the inner bottom surface 32a of the bottom plate 32, and the ceiling surface 33a of the top plate 33 as defining surfaces of the communication port 62.

[0052] It can also be said that the communication opening 62 is defined by the first non-joint edge 41d moving away from the second inner surface 42a of the second partition portion 42 in the second direction Y. The communication opening 62 is open over the entire vertical direction Z so as to connect the inner bottom surface 32a of the bottom plate 32 and the ceiling surface 33a of the top plate 33. In other words, the communication opening 62 is formed with the inner surface of the container 31 facing the vertical direction Z as a part of the defining surface of the communication opening 62.

[0053] 6, when the communication port 62 is viewed in the first direction X, a rectangle is enclosed by lines along the first non-joint edge 41d, lines along the second inner surface 42a, lines along the inner bottom surface 32a, and lines along the ceiling surface 33a. The area of ​​this rectangle is defined as the opening area of ​​the communication port 62. The opening area of ​​the communication port 62 is 650 mm2 per 1 liter of the volume of the retention chamber 60. 2 It is set to be equal to or greater than this.

[0054] Here, a position that divides the retention chamber 60 in half in the first direction X is defined as an intermediate position P of the retention chamber 60. The communication port 62 is disposed at a position in the first direction X closer to the second end plate 37, which is the second end in the first direction X, than the intermediate position P. Specifically, the communication port 62 is disposed in the partition wall 40 that defines the retention chamber 60.

[0055] The vessel 31 has an anode off-gas inlet 50 , a cathode off-gas inlet 51 , an exhaust port 52 , and a drain port 53 . <Anode off-gas inlet> As shown in FIGS. 2 to 6, the anode off-gas inlet 50 allows the anode off-gas discharged from the fuel cell stack 11 to flow into the retention chamber 60. The anode off-gas inlet 50 is disposed in the first end plate 36. That is, the anode off-gas inlet 50 is disposed in the first end plate 36 which is the first end of the retention chamber 60 in the first direction X. As described above, the communication port 62 is disposed in the partition wall 40 which defines the retention chamber 60. Therefore, the anode off-gas inlet 50 and the communication port 62 are disposed at both ends of the retention chamber 60 in the first direction X.

[0056] The anode off-gas inlet 50 penetrates the first end plate 36 in the plate thickness direction. The anode off-gas inlet 50 is a circular hole. The anode off-gas inlet 50 is disposed at a position close to the upper end of the first end plate 36 among the positions of the first end plate 36 in the vertical direction Z. The anode off-gas inlet 50 is spaced upward from the inner bottom surface 32a of the bottom plate 32 in the vertical direction Z. It is preferable that the anode off-gas inlet 50 is spaced upward from the inner bottom surface 32a of the bottom plate 32 in the vertical direction Z. The position of the first end plate 36 in the second direction Y is arbitrary.

[0057] The anode offgas discharge passage 20 is connected to the anode offgas inlet 50. That is, the anode offgas discharge passage 20 connected to the fuel cell stack 11 is connected to the anode offgas inlet 50. The second discharge passage 19 of the anode offgas discharge passage 20 is defined by the anode offgas discharge pipe 19a connecting the gas-liquid separator 14 and the diluter 30. When the exhaust valve 24 is opened, the anode offgas is discharged from the gas-liquid separator 14 toward the diluter 30. The anode offgas flowing through the second discharge passage 19 flows into the retention chamber 60 via the anode offgas inlet 50. The discharge amount of the anode offgas when the exhaust valve 24 is opened once is the amount of the anode offgas that flows from the anode offgas discharge passage 20 into the retention chamber 60 via the anode offgas inlet 50. The discharge amount of the anode offgas is smaller than the volume of the retention chamber 60. In other words, the volume of the retention chamber 60 is larger than the discharge amount of the anode off-gas. The discharge amount of the anode off-gas is maximum when the exhaust valve 24 is opened for the longest time and the pressure of the anode off-gas is maximum within the operating range of the fuel cell system 10. The volume of the retention chamber 60 is preferably set to be larger than the maximum discharge amount of the anode off-gas.

[0058] At this time, water contained in the anode off-gas also flows into the retention chamber 60. The water contained in the anode off-gas is separated from the anode off-gas in the retention chamber 60. The water separated from the anode off-gas accumulates in the retention chamber 60 on the inner bottom surface 32a.

[0059] When the exhaust valve 24 is closed, anode off-gas remains in the retention chamber 60. When the exhaust valve 24 is opened and anode off-gas flows into the retention chamber 60 from the anode off-gas inlet 50, the anode off-gas remaining in the retention chamber 60 is pushed out of the retention chamber 60 via the communication port 62, with a volume corresponding to the discharge amount.

[0060] The communication port 62 communicates the retention chamber 60 and the dilution chamber 61 in the first direction X. Therefore, the anode off-gas pushed out from the communication port 62 flows in the first direction X from the retention chamber 60 toward the dilution chamber 61. The direction in which the anode off-gas flows out from the retention chamber 60 to the dilution chamber 61 via the communication port 62 is defined as the outflow direction. This outflow direction coincides with the first direction X. Water accumulated on the inner bottom surface 32a of the retention chamber 60 flows out from the retention chamber 60 to the dilution chamber 61 via the communication port 62.

[0061] <Cathode off-gas inlet> The cathode offgas inlet 51 allows the cathode offgas discharged from the fuel cell stack 11 to flow into the dilution chamber 61. The cathode offgas inlet 51 is disposed in the top plate 33. The cathode offgas inlet 51 is a circular hole. The cathode offgas inlet 51 penetrates the top plate 33 in the plate thickness direction. The cathode offgas inlet 51 is disposed at a position on the top plate 33 closer to the first end plate 36 in the first direction X. Therefore, it can be said that the cathode offgas inlet 51 is disposed at a position not facing the communication port 62 in the outflow direction of the anode offgas from the communication port 62.

[0062] The cathode offgas discharge path 22 is connected to the cathode offgas inlet 51. The cathode offgas discharge path 22 is defined by a cathode offgas discharge pipe 22a that connects the fuel cell stack 11 and the diluter 30. The cathode offgas flowing through the cathode offgas discharge path 22 flows into the dilution chamber 61 via the cathode offgas inlet 51.

[0063] The cathode off-gas flowing into the dilution chamber 61 from the cathode off-gas inlet 51 comes into contact with the inner bottom surface 32a of the bottom plate 32, the ceiling surface 33a of the top plate 33, the inner surface 35a of the second side plate 35, and the second outer surface 42b of the second partition portion 42, and changes direction toward the second end plate 37.

[0064] The cathode offgas that has flowed into the dilution chamber 61 flows through the first chamber 61a in the first direction X, and then flows through the second chamber 61b. In the second chamber 61b, the cathode offgas comes into contact with the inner bottom surface 32a of the bottom plate 32, the ceiling surface 33a of the top plate 33, the inner surface 37a of the second end plate 37, and the first outer surface 41b of the first partition portion 41. This contact changes the flow direction of the cathode offgas. The flow direction of the cathode offgas in the second chamber 61b becomes the second direction Y. Then, the cathode offgas that has flowed into the second chamber 61b flows through the second chamber 61b toward the exhaust port 52.

[0065] <Exhaust port> The exhaust port 52 is disposed in the second end plate 37 of the container 31. The exhaust port 52 is disposed in the second end plate 37 closer to the first side plate 34 in the second direction Y. The exhaust port 52 penetrates the second end plate 37 in the plate thickness direction. The exhaust port 52 is connected to a gas exhaust path 25. The gas exhaust path 25 is defined by a gas exhaust pipe 25a. The gas exhaust pipe 25a is connected to the diluter 30.

[0066] The cathode off-gas that has flowed into the dilution chamber 61 flows through the first chamber 61a and the second chamber 61b toward the exhaust port 52. The anode off-gas pushed out of the retention chamber 60 flows into the dilution chamber 61 via the communication port 62. Then, the exhaust gas in which the anode off-gas and the cathode off-gas are mixed in the dilution chamber 61 is discharged to the outside of the diluter 30 via the exhaust port 52.

[0067] <Drain port> The drain outlet 53 is disposed in the bottom plate 32 of the container 31. The drain outlet 53 is disposed on the bottom plate 32 closer to the second end plate 37 in the first direction X and closer to the second side plate 35 in the second direction Y. The drain outlet 53 penetrates the bottom plate 32 in the plate thickness direction. A drainage channel 21 is connected to the drain outlet 53. The water that flows out into the dilution chamber 61 is discharged from the drain outlet 53 to the outside of the diluter 30. The water discharged to the outside of the diluter 30 is discharged via the drainage channel 21 to the drain tank 15.

[0068] <effect> The function of the diluter 30 will now be described. When the exhaust valve 24 is closed, the cathode offgas discharged from the fuel cell stack 11 flows into the dilution chamber 61 via the cathode offgas discharge path 22 and the cathode offgas inlet 51. The cathode offgas that has flowed into the dilution chamber 61 flows through the first chamber 61a and the second chamber 61b toward the outlet 52. The cathode offgas that has flowed through the dilution chamber 61 is discharged to the outside of the diluter 30 via the outlet 52.

[0069] When the exhaust valve 24 of the second discharge passage 19 is opened once, the anode off-gas is discharged from the gas-liquid separator 14 toward the diluter 30. Then, a constant amount of the anode off-gas is discharged and flows into the retention chamber 60 via the anode off-gas inlet 50. The anode off-gas that has flowed into the retention chamber 60 flows in the first direction X toward the communication port 62 along the inner bottom surface 32a of the bottom plate 32, the ceiling surface 33a of the top plate 33, the inner surface 34a of the first side plate 34, and the second inner surface 42a of the second partition portion 42. In other words, the anode off-gas that has flowed into the retention chamber 60 flows in the first direction X without significantly changing its flow direction.

[0070] Furthermore, when the anode off-gas flows into the retention chamber 60, the anode off-gas remaining in the retention chamber 60 is pushed out of the retention chamber 60 from the communication port 62 at a volume corresponding to the discharge amount. The anode off-gas pushed out of the retention chamber 60 is mixed with the flowing cathode off-gas in the second chamber 61b of the dilution chamber 61. The anode off-gas mixed with the cathode off-gas is discharged from the exhaust port 52 as exhaust gas.

[0071] According to the above embodiment, the following effects can be obtained. (1) The anode off-gas inlet 50 is disposed in the first end plate 36 that defines the retention chamber 60. The communication port 62 is disposed in the partition wall 40 that defines the retention chamber 60. The anode off-gas inlet 50 and the communication port 62 are disposed at both ends of the retention chamber 60 in the first direction X. Therefore, the anode off-gas that flows into the retention chamber 60 from the anode off-gas inlet 50 flows in the retention chamber 60 toward the communication port 62 along the first direction X without significantly changing its flow direction. As a result, the anode off-gas that flows into the retention chamber 60 can be prevented from abruptly changing its flow direction. Therefore, the diluter 30 can prevent noise caused by abruptly changing the flow direction.

[0072] Moreover, the water separated from the anode off-gas accumulates in the retention chamber 60. The communication port 62 opens between the inner bottom surface 32a of the bottom plate 32 and the ceiling surface 33a of the top plate 33, which face each other in the vertical direction Z. That is, the communication port 62 is formed with the inner bottom surface 32a and the ceiling surface 33a as part of the boundary surface of the communication port 62. Therefore, the communication port 62 opens over the entire dimension of the container 31 in the vertical direction Z. The anode off-gas flowing out to the dilution chamber 61 via the communication port 62 passes above the communication port 62, and the water passes below the communication port 62. That is, the anode off-gas and the water pass through the communication port 62 while being separated into upper and lower portions. Therefore, the water can be prevented from being entrained in the anode off-gas near the communication port 62. As a result, the diluter 30 can suppress the generation of noise caused by the water being entrained in the anode off-gas. Therefore, the diluter 30 can suppress noise generation as a whole without increasing the number of parts of the diluter 30 and without increasing manufacturing costs.

[0073] (2) The volume of the retention chamber 60 is set to be larger than the discharge amount of the anode off-gas. The larger the volume of the retention chamber 60, the slower the flow rate of the anode off-gas pushed out from the communication port 62. And the slower the flow rate of the anode off-gas pushed out from the communication port 62, the smaller the wind noise generated when the anode off-gas passes through the communication port 62. Thus, the diluter 30 can reduce the wind noise generated when the anode off-gas passes through the communication port 62.

[0074] (3) The anode off-gas inlet 50 is spaced upward from the inner bottom surface 32a of the bottom plate 32. This makes it possible to prevent water accumulated on the inner bottom surface 32a from being entrained in the anode off-gas when the anode off-gas flows into the retention chamber 60 from the anode off-gas inlet 50. This makes it possible for the diluter 30 to prevent noise caused by water being entrained in the anode off-gas.

[0075] (4) The cathode offgas inlet 51 is disposed closer to the first end plate 36 on the top plate 33. The communication port 62 is disposed closer to the second end plate 37 in the first direction X than the cathode offgas inlet 51. Thus, the cathode offgas inlet 51 is disposed at a position not facing the communication port 62. This makes it possible to prevent the anode offgas flowing from the retention chamber 60 to the dilution chamber 61 via the communication port 62 from colliding with the cathode offgas flowing from the cathode offgas inlet 51 into the dilution chamber 61. Therefore, the diluter 30 can prevent noise caused by collision between the anode offgas and the cathode offgas.

[0076] (5) The opening area of ​​the communication port 62 is 650 mm per 1 liter of the volume of the retention chamber 60. 2 or more. The larger the opening area of ​​the communication port 62, the slower the flow rate of the anode off-gas pushed out from the communication port 62. The slower the flow rate of the anode off-gas pushed out from the communication port 62, the smaller the wind noise generated when the anode off-gas passes through the communication port 62. Thus, the diluter 30 can reduce the wind noise generated when the anode off-gas passes through the communication port 62.

[0077] (6) The communication port 62 communicates the retention chamber 60 and the dilution chamber 61 in the first direction X between the first non-joint edge 41d of the first partition portion 41 and the second inner surface 42a of the second partition portion 42. That is, the communication port 62 opens so as to flow the anode off-gas in the first direction X. For example, a comparative example is a case in which the communication port 62 penetrates the bottom plate 32 in the plate thickness direction or opens near the second joint edge 42c of the second partition portion 42. In this embodiment, unlike the comparative example, the flow of the anode off-gas does not change abruptly. Therefore, by specifying the position of the communication port 62, it is possible to suppress the generation of noise caused by abrupt changes in the flow of the anode off-gas.

[0078] (7) After flowing through the first chamber 61a, the cathode off-gas bends in the second chamber 61b and flows toward the exhaust port 52. The first chamber 61a extends longitudinally in the first direction X, similar to the retention chamber 60. The second chamber 61b extends along the second end plate 37 so as to intersect with the first chamber 61a. This prevents the cathode off-gas flowing through the dilution chamber 61 from suddenly changing in flow. Therefore, even if the dilution chamber 61 is L-shaped, the diluter 30 can prevent noise caused by suddenly changing the flow of the cathode off-gas.

[0079] (8) The container 31 and the partition wall 40 of the diluter 30 are made of metal plates. The diluter 30 can be manufactured from sheet metal. Therefore, the manufacturing cost of the diluter 30 is low. (9) The flow direction of the anode offgas from the communication port 62 is the first direction X. The flow direction of the cathode offgas in the second chamber 61b is the second direction Y. Therefore, the flow direction of the anode offgas intersects with the flow direction of the cathode offgas in the second chamber 61b. Therefore, the anode offgas that has flowed into the dilution chamber 61 from the communication port 62 is prevented from being discharged from the discharge port 52 without being mixed with the cathode offgas. As a result, the efficiency of diluting the anode offgas with the cathode offgas in the second chamber 61b can be increased.

[0080] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs. The opening area of ​​the communication port 62 is 650 mm per 1 liter of the volume of the retention chamber 60. 2 It may be set to less than

[0081] The position of the cathode off-gas inlet 51 on the top plate 33 may be changed as appropriate as long as the cathode off-gas inlet 51 communicates with the dilution chamber 61 . As long as the cathode off-gas inlet 51 communicates with the dilution chamber 61, the cathode off-gas inlet 51 may be disposed at any position on the first side plate 34, the second side plate 35, or the first end plate 36. When the cathode off-gas inlet 51 is disposed on the second end plate 37, the cathode off-gas inlet 51 may be disposed at any position that does not face the communication port 62 in the outflow direction of the anode off-gas from the communication port 62.

[0082] The position of the anode off-gas inlet 50 in the first end plate 36 does not have to be separated from the inner bottom surface 32a. The volume of the retention chamber 60 may be equal to or smaller than the amount of anode off-gas discharged when the exhaust valve 24 is opened once.

[0083] Although the communication opening 62 is formed by the gap between the first partition portion 41 and the second partition portion 42, this is not limited thereto. The first partition portion 41 and the second partition portion 42 are joined to form the partition wall 40 into an L shape. An edge of the second partition portion 42, which is one end edge of the L shape of the partition wall 40, is joined to the inner surface 36a of the first end plate 36, and an edge of the first partition portion 41, which is the other end edge of the L shape, is joined to the inner surface 34a of the first side plate 34. A slit may be formed in any one of the long edge directions of the first partition portion 41, and the slit may be used as the communication opening 62. In this case, the communication opening 62 is also formed with the inner bottom surface 32a and the ceiling surface 33a as part of the boundary surface of the communication opening 62.

[0084] Alternatively, in the L-shaped partition wall 40, a slit may be formed in the second partition portion 42 at a position closer to the first partition portion 41, and the slit may be used as the communication port 62. In this case, the communication port 62 is also formed with the inner bottom surface 32a and the ceiling surface 33a as part of the defining surface of the communication port 62. In this case, the flow direction of the anode off-gas from the retention chamber 60 to the dilution chamber 61 is the second direction Y. Accordingly, the cathode off-gas inlet 51 is disposed at a position not facing the flow direction of the anode off-gas from the communication port 62.

[0085] Each of the communication openings 62 formed by the slits is disposed at a position closer to the second end plate 37, which is the second end in the first direction X, than the intermediate position P in the first direction X. The opening shape of the communication port 62 may be changed as appropriate as long as the inner bottom surface 32a and the ceiling surface 33a are formed as part of the boundary surface of the communication port 62. For example, as shown in FIG. 7, the upper end edge of the first partitioning portion 41 may be moved away from the ceiling surface 33a over the entire long edge direction to open the communication port 62 over the entire long edge direction of the first partitioning portion 41. The communication port 62 may also be opened by moving the first joint edge 41c of the first partitioning portion 41 away from the inner surface 34a of the first side plate 34. In this case, the portion of the communication port 62 closer to the inner bottom surface 32a is narrower than the portion closer to the ceiling surface 33a. Therefore, the anode off-gas is more likely to flow out from the retention chamber 60 to the dilution chamber 61, while the water is less likely to flow out from the retention chamber 60 to the dilution chamber 61. Therefore, the anode off-gas and water are less likely to mix at the communication port 62, so that the generation of noise caused by water being entrained in the anode off-gas can be suppressed.

[0086] The dilution chamber 61 may be composed of only the first chamber 61a. In this case, it can be said that each of the retention chamber 60 and the dilution chamber 61 has a portion that extends from the first end to the second end in the first direction X and is aligned in the second direction Y with the second partition portion 42 of the partition wall 40 therebetween.

[0087] ○ The first end plate 36 is formed so that the portion defining the dilution chamber 61 and the portion defining the retention chamber 60 are stepped. The portion defining the dilution chamber 61 of the first end plate 36 is located closer to the second end plate 37 in the first direction X than the portion defining the retention chamber 60. In this way, the dimension of the first chamber 61a of the dilution chamber 61 in the first direction X is made shorter than that of the embodiment. In this configuration, the first chamber 61a of the dilution chamber 61 is aligned in the second direction Y with respect to a part of the retention chamber 60 with the second partition 42 in between. Therefore, it can be said that the retention chamber 60 has a portion that extends from the first end to the second end in the first direction X and is aligned in the second direction Y with the partition wall 40 in between.

[0088] The outlet 52 may be disposed in the bottom plate 32 , the top plate 33 , the first side plate 34 , or the second side plate 35 instead of the second end plate 37 . The container 31 and the partition wall 40 may be made of resin.

[0089] The container 31 may be in the form of a cylindrical pipe. The fuel cell may be composed of a single fuel cell. [Explanation of symbols]

[0090] P...intermediate position, S...internal space, X...first direction, Y...second direction, Z...vertical direction, 11...fuel cell stack as a fuel cell, 20...anode off-gas exhaust passage, 24...exhaust valve, 30...diluter, 31...container, 32...bottom plate, 32a...inner bottom surface as an inner surface, 33...top plate, 33a...ceiling surface as an inner surface, 40...partition wall, 50...anode off-gas inlet, 51...cathode off-gas inlet, 60...retention chamber, 61...dilution chamber, 62...communication port.

Claims

1. a container defining an interior space; A partition wall that divides the internal space into a retention chamber and a dilution chamber; an anode off-gas inlet provided in the container for allowing an anode off-gas discharged from the fuel cell to flow into the retention chamber; a cathode off-gas inlet provided in the container for allowing a cathode off-gas discharged from the fuel cell to flow into the dilution chamber; a communication port that communicates the retention chamber and the dilution chamber inside the container; A diluter for diluting the anode off-gas with the cathode off-gas, A direction along a horizontal plane, the longitudinal direction of the container is defined as a first direction, and one of the directions along the horizontal plane that is perpendicular to the first direction is defined as a second direction. Each of the retention chamber and the dilution chamber has a portion extending from a first end to a second end in the first direction and aligned in the second direction with the partition wall therebetween, the anode off-gas inlet is disposed at a first end of the residence chamber in the first direction, If the position that divides the retention chamber in half in the first direction is defined as the intermediate position of the retention chamber, the communication port is positioned at a position in the first direction closer to the second end in the first direction than the intermediate position, and the communication port is formed such that the inner surface of the container facing the vertical direction is part of the boundary surface of the communication port.

2. 2. The dilution device of claim 1, wherein an anode off-gas exhaust passage connected to the fuel cell is connected to the anode off-gas inlet, and an exhaust valve is provided in the anode off-gas exhaust passage, and when the amount of anode off-gas flowing from the anode off-gas exhaust passage through the anode off-gas inlet into the retention chamber when the exhaust valve is opened once is defined as a discharge amount, the volume of the retention chamber is greater than the discharge amount.

3. The container has a bottom plate and a top plate opposed to each other in the vertical direction, the inner surfaces of the container facing each other in the vertical direction are an inner bottom surface of the container formed by the bottom plate and a ceiling surface of the container formed by the top plate, The dilution device according to claim 1 or 2, wherein the anode off-gas inlet is spaced above the inner bottom surface of the container.

4. If the direction in which the anode off-gas flows from the retention chamber to the dilution chamber via the communication port is defined as an outflow direction, The dilution device according to any one of claims 1 to 3, wherein the cathode off-gas inlet is disposed at a position not opposing the communication port in the outflow direction.

5. The opening area of ​​the communication port is 650 mm per 1 liter of the volume of the retention chamber. ２ The diluter according to any one of claims 1 to 4, wherein the dilution device is set as described above.

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