Diluter for fuel cell system

Abstract

To provide a diluter for a fuel cell system, the diluter being capable of inhibiting generated water from being discharged from an air outlet with mixed gas.SOLUTION: A water outlet 53 is disposed upstream in a flow direction F of an air outlet 52. On an inner bottom surface 32a, a blocking plate 60 for blocking generated water is disposed. The blocking plate 60 is disposed upstream in the flow direction F of the water outlet 53. The blocking plate 60 has a first edge 60c apart from a second side plate 35. The blocking plate 60 has a second edge 60d apart from a first side plate 34.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a diluter for a fuel cell system. [Background technology]

[0002] The diluter for a fuel cell system has a retention chamber, a dilution chamber, a drain port, and an exhaust port. Anode off-gas discharged from the fuel cell and containing generated water flows into the retention chamber. Cathode off-gas discharged from the fuel cell and containing generated water flows into the dilution chamber. The anode off-gas discharged from the retention chamber and the cathode off-gas are mixed in the dilution chamber. The drain port opens into an inner bottom surface that defines the dilution chamber, and discharges the generated water accumulated on the inner bottom surface from the dilution chamber. The exhaust port discharges a mixed gas of the cathode off-gas and the anode off-gas from the dilution chamber.

[0003] For example, the diluter described in Patent Document 1 dilutes the anode off-gas with the cathode off-gas, and then discharges this mixed gas from an exhaust pipe to the outside of the diluter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-187921 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the dilution device described in Patent Document 1, there is a risk that a part of the generated water may be discharged from the exhaust pipe together with the mixed gas. Therefore, it is desirable to suppress the generated water from being discharged from the exhaust pipe together with the mixed gas. [Means for solving the problem]

[0006] A diluter for a fuel cell system for solving the above problems includes a retention chamber into which an anode off-gas discharged from a fuel cell and containing generated water flows, and a dilution chamber into which a cathode off-gas discharged from the fuel cell and containing generated water flows, the dilution chamber in which the anode off-gas discharged from the retention chamber and the cathode off-gas are mixed, a drain port that opens into an inner bottom surface of the dilution chamber that defines the dilution chamber and discharges the generated water accumulated on the inner bottom surface, and a drain port that opens into an inner side surface of the dilution chamber that defines the dilution chamber and intersects with the inner bottom surface to discharge the anode off-gas and the cathode off-gas. The present invention relates to a diluter for a fuel cell system having a cathode off-gas mixture and an exhaust port for discharging the cathode off-gas mixture, wherein, if the direction in which the cathode off-gas that has flowed into the dilution chamber flows toward the exhaust port is defined as a flow direction, the drain port is located upstream of the exhaust port in the flow direction, and a blocking plate for blocking the generated water is located on the inner bottom surface, and the blocking plate is located upstream of the drain port in the flow direction, and at least one of both end edges of the blocking plate is separated from the inner surface of the dilution chamber.

[0007] According to this, when the generated water flows on the inner bottom surface toward the exhaust port together with the flow of the mixed gas, the generated water is temporarily blocked by the blocking plate. Therefore, the generated water is prevented from flowing toward the exhaust port, and the generated water is prevented from accumulating near the exhaust port inside the diluter for a fuel cell system. Then, a part of the mixed gas flows through between the edge of the blocking plate and the inner surface so as to go around the blocking plate. Then, the generated water blocked by the blocking plate flows through between the edge of the blocking plate and the inner surface together with the mixed gas, so that the generated water flows toward the drain port arranged downstream of the blocking plate in the flow direction. Then, the generated water is discharged from the drain port to the outside of the diluter. Therefore, the generated water introduced into the dilution chamber is easily discharged from the drain port. Therefore, it is possible to prevent the generated water from being discharged from the dilution chamber together with the mixed gas.

[0008] In the dilution device for a fuel cell system, the blocking plate may be disposed at a position aligned with at least a portion of the drain outlet in the flow direction. This allows the produced water to easily flow around the blocking plate together with the mixed gas and then be discharged to the outside of the dilution chamber through the drain outlet.

[0009] In the above dilution device for a fuel cell system, both end edges of the blocking plate may be spaced apart from the inner side surface of the dilution chamber. According to this, the generated water once blocked by the blocking plate can flow through two paths: between one of the two end edges of the blocking plate and the inner surface, and between the other of the two end edges of the blocking plate and the inner surface. Therefore, when the generated water blocked by the blocking plate flows around the blocking plate, the generated water is more likely to reach the drain outlet. Therefore, the generated water can be easily discharged from the drain outlet.

[0010] In the dilution device for a fuel cell system, an upper end of the blocking plate may be located vertically lower than a lower end of the exhaust port. With this, even if the generated water is blown up into the mixed gas, it is more difficult for the blown up generated water to reach a position vertically above the lower end of the exhaust port than when the upper end of the blocking plate is positioned vertically above the lower end of the exhaust port.

[0011] In addition, the generated water may accumulate near the exhaust port without being discharged from the drain port. Even if the volume of the accumulated generated water increases, the volume of the accumulated generated water is less likely to reach the lower end of the exhaust port than when the upper end of the blocking plate is located vertically above the lower end of the exhaust port. From the above, the generated water introduced into the dilution chamber is less likely to be discharged from the exhaust port.

[0012] In the diluter for a fuel cell system described above, when the exhaust port is viewed in the flow direction, the exhaust port may be disposed away from the drain port. This makes it difficult for the generated water that is not discharged from the drain outlet to be carried to the exhaust outlet by the flow of the mixed gas. Effect of the Invention

[0013] According to this invention, it is possible to prevent the generated water from being discharged from the exhaust port together with the mixed gas. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a fuel cell system. [Diagram 2] FIG. 2 is a perspective view showing a diluter for a fuel cell system. [Diagram 3] FIG. 2 is a perspective view showing the inside of a diluter for a fuel cell system. [Figure 4] 4 is a cross-sectional view taken along line 4-4 in FIG. 2. [Diagram 5] 5 is a cross-sectional view taken along line 5-5 in FIG. 2. [Figure 6] 6 is a cross-sectional view taken along line 6-6 in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, one embodiment of a diluter for a fuel cell system 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 as a fuel cell, a hydrogen tank 12, an air compressor 13, a gas-liquid separator 14, a drain tank 15, and a fuel cell system diluter 30. The fuel cell system 10 also includes an anode gas supply channel 16, a cathode gas supply channel 17, a first discharge channel 18, a second discharge channel 19, a drain channel 21, a cathode off-gas discharge channel 22, an anode gas circulation channel 23, a gas discharge channel 24, and an exhaust valve 25.

[0016] <Fuel cell stack> The fuel cell stack 11 is a stack of multiple fuel cells. The fuel cells are solid molecular fuel cells. The fuel cell stack 11 generates power when supplied with hydrogen gas as an anode gas and an oxidant gas as a cathode gas. The oxidant gas is, for example, air.

[0017] <Hydrogen tank> The hydrogen tank 12 stores hydrogen gas. <Air compressor> The air compressor 13 compresses the air.

[0018] <Gas-liquid separator> The gas-liquid separator 14 separates generated water contained in the anode off-gas discharged from the fuel cell stack 11 from the anode off-gas.

[0019] <Drainage tank> The drain tank 15 stores the product water separated from the anode off-gas and the cathode off-gas.

[0020] <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.

[0021] <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.

[0022] <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 produced water, which is water produced when hydrogen reacts with oxygen.

[0023] <Second discharge path> The second discharge path 19 connects the gas-liquid separator 14 and the diluter 30 for the fuel cell system. The first discharge path 18, the gas-liquid separator 14, and the second discharge path 19 configure an anode off-gas discharge path 20. The anode off-gas discharge path 20 connects the fuel cell stack 11 and the diluter 30 for the fuel cell system.

[0024] 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 for the fuel cell system. 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 the generated water that could not be separated from the anode off-gas by the gas-liquid separator 14 flows through the second discharge path 19.

[0025] <Gas exhaust passage> The gas exhaust passage 24 is connected to a diluter 30 for the fuel cell system. <Exhaust valve> The exhaust valve 25 is provided in the anode off-gas discharge path 20. Specifically, the exhaust valve 25 is provided in the second discharge path 19 of the anode off-gas discharge path 20. The exhaust valve 25 opens and closes the second discharge path 19, which is a part of the anode off-gas discharge path 20. The exhaust valve 25 is constantly closed. When a predetermined amount of anode off-gas is stored in the gas-liquid separator 14, the exhaust valve 25 is instantaneously opened. When the exhaust valve 25 is opened once, the anode off-gas is discharged from the gas-liquid separator 14.

[0026] <Drainage channel> The drainage channel 21 connects the fuel cell system diluter 30 and the drainage tank 15. The generated water discharged from the fuel cell system 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.

[0027] <Cathode off-gas exhaust passage> The cathode offgas discharge path 22 connects a cathode (not shown) of the fuel cell stack 11 to the fuel cell system dilutor 30. The cathode offgas flows through the cathode offgas discharge path 22 from the fuel cell stack 11 toward the fuel cell system dilutor 30. The cathode offgas mainly contains air containing unreacted oxygen in the fuel cell stack 11 and produced water, which is water produced when hydrogen and oxygen react with each other.

[0028] <Diluter for fuel cell systems> As shown in FIGS. 2, 3, 4, 5, and 6, the diluter 30 for a fuel cell system has a container 31, a partition wall 40, and a communication port G1.

[0029] The partition wall 40 divides the internal space S1 of the container 31 into two chambers, a retention chamber S11 and a dilution chamber S12. The communication port G1 communicates between the retention chamber S11 and the dilution chamber S12. Assuming that the diluter 30 for a fuel cell system is placed on a horizontal plane, the direction of gravity is indicated by the Z axis, and 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.

[0030] <Container> The container 31 has a rectangular parallelepiped shape with its longitudinal direction extending in the first direction X. The longitudinal direction of the container 31 coincides with the first direction X. The lateral direction of the container 31 coincides with the second direction Y.

[0031] The container 31 has a bottom plate 32 and a top plate 33. The bottom plate 32 and the top plate 33 are rectangular plates. The bottom plate 32 and the top plate 33 face each other in the vertical direction Z. The long edges of the bottom plate 32 and the long edges of the top plate 33 extend in the first direction X. The short edges of the bottom plate 32 and the short edges of 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.

[0032] 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.

[0033] The container 31 has a first side plate 34, a second side plate 35, a first end plate 36, and a second end plate 37. The first side plate 34, the second side plate 35, the first end plate 36, and the second end plate 37 are each shaped like a rectangular plate.

[0034] The first side plate 34 and the second side plate 35 face each other in the second direction Y. The long edges of the first side plate 34 and the long edges of the second side plate 35 extend in the first direction X. The short edges of the first side plate 34 and the short edges of the second side plate 35 extend in the vertical direction Z. The plate thickness direction of the first side plate 34 and the plate thickness direction of the second side plate 35 coincide with the second direction Y. The first side plate 34 and the second side plate 35 are arranged so as to be perpendicular to the inner bottom surface 32a.

[0035] 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 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 inner surface 34a of the first side plate 34 and the inner surface 35a of the second side plate 35 intersect with the inner bottom surface 32a.

[0036] The first end plate 36 and the second end plate 37 face each other in the first direction X. The long edges of the first end plate 36 and the long edges of the second end plate 37 extend in the second direction Y. The short edges of the first end plate 36 and the short edges of the second end plate 37 extend in the vertical direction Z. The thickness directions of the first end plate 36 and the second end plate 37 coincide with the first direction X. The first end plate 36 and the second end plate 37 are arranged perpendicular to the inner bottom surface 32a.

[0037] The first end plate 36 has an inner surface 36a on one side in the plate thickness direction and an outer surface 36b on the other side in the plate thickness direction. The second end plate 37 has an inner surface 37a on one side in the plate thickness direction and an outer surface 37b on the other side in the plate thickness direction. The inner surface 36a of the first end plate 36 and the inner surface 37a of the second end plate 37 intersect with the inner bottom surface 32a.

[0038] 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 long edges of the top plate 33, the long edges of the first side plate 34, and the long edges of the second side plate 35 extend.

[0039] <Interior space> The internal space S1 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 S1. The internal space S1 is a space that extends longitudinally in the longitudinal direction of the container 31, i.e., in the first direction X.

[0040] <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.

[0041] 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.

[0042] The first partition 41 has a first joint edge 41c at one end edge in the longitudinal direction and a first non-joined edge 41d at the other end edge in the longitudinal 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 first non-joined edge 41d of the first partition 41 is separated from the second partition 42 in the second direction Y. The first non-joined edge 41d is not joined to the second partition 42. In addition, the first non-joined edge 41d faces the second partition 42 in the second direction Y.

[0043] 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.

[0044] The second partition portion 42 has a second joining edge 42c at one longitudinal end edge and a second non-joining edge 42d at the other longitudinal end edge. The second joining edge 42c of the second partition portion 42 is joined to the inner surface 36a of the first end plate 36. The second non-joining edge 42d of the second partition portion 42 is separated from the first partition portion 41 in the first direction X. The second non-joining edge 42d is not joined to the first partition portion 41.

[0045] The lower edge of the first partition portion 41 and the lower edge of the second partition portion 42 are joined to the inner bottom surface 32a of the bottom plate 32. The upper edge of the first partition portion 41 and the upper edge of the second partition portion 42 are joined to the ceiling surface 33a of the top plate 33. The partition wall 40 divides the internal space S1 into two chambers: a retention chamber S11 and a dilution chamber S12.

[0046] <Retention chamber> The retention chamber S11 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.

[0047] The retention chamber S11 is defined in a rectangular parallelepiped shape with its longitudinal axis extending in the first direction X. The retention chamber S11 may not be constant in at least one of its dimension in the second direction Y and its dimension in the vertical direction Z in the first direction X.

[0048] <Dilution chamber> The dilution chamber S12 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. Therefore, 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 are the inner surfaces of the dilution chamber S12 that intersect with the inner bottom surface 32a. The dilution chamber S12 is a space whose longitudinal direction extends from the first end plate 36 toward the second end plate 37.

[0049] A plane obtained by imaginarily extending the first partition portion 41 in the second direction Y is defined as a virtual plane M. The dilution chamber S12 is composed of a first chamber S121 and a second chamber S122. The first chamber S121 is a space defined by the inner surface 36a of the first end plate 36, the second outer surface 42b of the second partition portion 42, the imaginary 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.

[0050] The second chamber S122 is a space defined by the imaginary 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. The first chamber S121 is a space aligned with the retention chamber S11 in the second direction Y across the second partition 42. The second chamber S122 is a space aligned with the retention chamber S11 in the first direction X across the first partition 41. The second chamber S122 is a space aligned with the first chamber S121 in the first direction X across the imaginary plane M. When the dilution chamber S12 is viewed in the vertical direction Z, the dilution chamber S12 is defined in an L shape.

[0051] In the first direction X, the dilution chamber S12 has a constant dimension in the second direction Y and a constant dimension in the vertical direction Z. However, at least one of the dimensions of the dilution chamber S12 in the second direction Y and the vertical direction Z does not have to be constant.

[0052] <Communication port> The communication opening G1 communicates between the retention chamber S11 and the dilution chamber S12 inside the container 31. The communication opening G1 is defined by the second non-joint edge 42d, a part of the first inner surface 41a of the first partition portion 41 that faces the second non-joint edge 42d in the first direction X, the inner bottom surface 32a of the bottom plate 32, and the ceiling surface 33a of the top plate 33.

[0053] It can be said that the communication opening G1 is defined by the second non-joint edge 42d moving away from the first inner surface 41a of the first partition portion 41 in the first direction X. The communication opening G1 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. The communication opening G1 is disposed in the partition wall 40 that defines the retention chamber S11.

[0054] 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> The anode off-gas inlet 50 allows the anode off-gas discharged from the fuel cell stack 11 to flow into the retention chamber S11. 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 a first end in the first direction X of the retention chamber S11. Therefore, the anode off-gas inlet 50 and the communication port G1 are disposed at both ends of the retention chamber S11 in the first direction X.

[0055] 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 anode off-gas inlet 50 in the first end plate 36 is arbitrary in the second direction Y.

[0056] The anode offgas discharge path 20 is connected to the anode offgas inlet 50. That is, the anode offgas discharge path 20, which is connected to the fuel cell stack 11, is connected to the anode offgas inlet 50. The second discharge path 19 of the anode offgas discharge path 20 is defined by an anode offgas discharge pipe 19a that connects the gas-liquid separator 14 and the diluter 30 for the fuel cell system. When the exhaust valve 25 is opened, the anode offgas is discharged from the gas-liquid separator 14 toward the diluter 30 for the fuel cell system. The anode offgas flowing through the second discharge path 19 flows into the retention chamber S11 via the anode offgas inlet 50.

[0057] At this time, the generated water contained in the anode off-gas also flows into the retention chamber S11. Therefore, the anode off-gas that is discharged from the fuel cell stack 11 and contains generated water flows into the retention chamber S11. The generated water contained in the anode off-gas is separated from the anode off-gas in the retention chamber S11. The generated water separated from the anode off-gas accumulates on the inner bottom surface 32a of the retention chamber S11.

[0058] When the exhaust valve 25 is closed, anode off-gas is retained in the retention chamber S11. When the exhaust valve 25 is opened and the anode off-gas flows into the retention chamber S11 from the anode off-gas inlet 50, the anode off-gas retained in the retention chamber S11 is pushed out of the retention chamber S11 via the communication port G1.

[0059] The communication port G1 communicates the retention chamber S11 and the dilution chamber S12 in the second direction Y. Therefore, the anode off-gas pushed out from the communication port G1 flows in the second direction Y from the retention chamber S11 toward the dilution chamber S12. The direction in which the anode off-gas flows from the retention chamber S11 to the dilution chamber S12 via the communication port G1 is defined as the outflow direction. This outflow direction coincides with the second direction Y. The generated water accumulated on the inner bottom surface 32a of the retention chamber S11 flows out from the retention chamber S11 to the dilution chamber S12 via the communication port G1.

[0060] <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 S12. The cathode offgas inlet 51 is disposed in the top plate 33. The cathode offgas inlet 51 may be disposed in the first end plate 36. 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 in the top plate 33 closer to the first end plate 36 in the first direction X. Therefore, the cathode offgas inlet 51 is disposed at a position not facing the communication port G1 in the outflow direction of the anode offgas from the communication port G1.

[0061] 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 for the fuel cell system. The cathode offgas flowing through the cathode offgas discharge path 22 flows into the dilution chamber S12 via the cathode offgas inlet 51. The cathode offgas discharged from the fuel cell stack 11 and containing generated water flows into the dilution chamber S12.

[0062] The produced water contained in the cathode off-gas also flows into the dilution chamber S12. The produced water contained in the cathode off-gas is separated from the cathode off-gas in the dilution chamber S12. The produced water separated from the cathode off-gas flows on the inner bottom surface 32a in the dilution chamber S12.

[0063] The cathode offgas that has flowed into the first chamber S121 flows toward the exhaust port 52, which will be described later in detail. The cathode offgas that has flowed into the first chamber S121 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. This contact causes the cathode offgas to flow in a first direction X toward the exhaust port 52. If the direction in which the cathode offgas that has flowed into the dilution chamber S12 flows toward the exhaust port 52 is defined as a flow direction F, this flow direction F is the first direction X. The generated water in the first chamber S121 flows in the flow direction F together with the cathode offgas. The direction that runs along the inner bottom surface 32a of the bottom plate 32 and intersects with the flow direction F is defined as a width direction W. In this embodiment, the width direction W coincides with the second direction Y. Therefore, the width direction W is perpendicular to the flow direction F.

[0064] In the second chamber S122, the cathode off-gas comes into contact with 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 off-gas. The flow direction of the cathode off-gas in the second chamber S122 becomes the second direction Y. The cathode off-gas that has flowed into the second chamber S122 flows through the second chamber S122 toward the exhaust port 52.

[0065] <Exhaust port> The exhaust port 52 opens to the second end plate 37 of the container 31. The exhaust port 52 opens to the inner surface 37a, which is the inner surface of the dilution chamber S12. The exhaust port 52 is disposed on 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 has a circular hole shape. The exhaust port 52 is connected to the gas exhaust path 24. The gas exhaust path 24 is defined by a gas exhaust pipe 24a. The gas exhaust pipe 24a is connected to the diluter 30 for the fuel cell system. A tip 240a of the gas exhaust pipe 24a enters the dilution chamber S12.

[0066] The cathode offgas that has flowed into the dilution chamber S12 flows through the first chamber S121 and the second chamber S122 toward the exhaust port 52. The anode offgas pushed out of the retention chamber S11 flows into the dilution chamber S12 via the communication port G1. The anode offgas and the cathode offgas are mixed in the dilution chamber S12. That is, the anode offgas and the cathode offgas discharged from the retention chamber S11 are mixed in the dilution chamber S12. At this time, the anode offgas is diluted by the cathode offgas. The diluted anode offgas is discharged as a mixed gas to the outside of the diluter 30 for a fuel cell system via the exhaust port 52.

[0067] <Drain port> The drain outlet 53 opens in the bottom plate 32 of the container 31. The drain outlet 53 opens in the inner bottom surface 32a of the dilution chamber S12. The drain outlet 53 is disposed upstream of the exhaust outlet 52 in the flow direction F. The drain outlet 53 penetrates the bottom plate 32 in the plate thickness direction. The drain outlet 53 is a circular hole. The drainage channel 21 is connected to the drain outlet 53. The generated water flowing out to the dilution chamber S12 is discharged to the drain tank 15 via the drainage channel 21. That is, the drain outlet 53 discharges the generated water accumulated on the inner bottom surface 32a of the dilution chamber S12. When the exhaust outlet 52 is viewed in the flow direction F, the exhaust outlet 52 is disposed away from the drain outlet 53 in the width direction W. Specifically, the exhaust outlet 52 is disposed closer to the first side plate 34 in the width direction W, and the drain outlet 53 is disposed closer to the second side plate 35 in the width direction W.

[0068] <Blocking board> The diluter 30 for the fuel cell system has a blocking plate 60. The blocking plate 60 is a rectangular plate. The blocking plate 60 is formed perpendicular to the bottom plate 32 of the container 31. The blocking plate 60 is disposed upstream of the drainage outlet 53 in the flow direction F. The blocking plate 60 is disposed in a position aligned with the entire drainage outlet 53 in the flow direction F. Therefore, the blocking plate 60 stands up at any position of the drainage outlet 53 upstream of the flow direction F from the drainage outlet 53. The direction in which the drainage outlet 53 and the blocking plate 60 are aligned is defined as the alignment direction. This alignment direction coincides with the first direction X. In this case, the width direction W is along the inner bottom surface 32a and also intersects with the alignment direction. In this embodiment, the width direction W is along the inner bottom surface 32a and is also perpendicular to the alignment direction, so the width direction W coincides with the second direction Y.

[0069] The blocking plate 60 has a first surface 60a on one side in the plate thickness direction and a second surface 60b on the other side in the plate thickness direction. The long edges of the blocking plate 60 extend in the second direction Y. The short edges of the blocking plate 60 extend in the vertical direction Z. The first surface 60a faces a part of the inner surface 36a of the first end plate 36 and a part of the first outer surface 41b of the first partition portion 41 in the first direction X. The second surface 60b faces the inner surface 37a of the second end plate 37 in the first direction X.

[0070] The blocking plate 60 has a first edge 60c at one end edge in the width direction W, and a second edge 60d at the other end edge in the width direction W. In other words, the blocking plate 60 has the first edge 60c at one end edge in the longitudinal direction, and a second edge 60d at the other end edge in the longitudinal direction. The first edge 60c of the blocking plate 60 is away from the second side plate 35 in the second direction Y. That is, the first edge 60c is not joined to the second side plate 35. The first edge 60c faces the second side plate 35 in the second direction Y. The second edge 60d of the blocking plate 60 is away from the first side plate 34 in the second direction Y. That is, the second edge 60d is not joined to the first side plate 34. The second edge 60d faces the first side plate 34 in the second direction Y. Therefore, both end edges of the blocking plate 60, that is, both end edges in the longitudinal direction, are spaced apart from the inner surface 35a of the second side plate 35 and the inner surface 34a of the first side plate 34, which are the inner surfaces.

[0071] A lower edge 60e of the blocking plate 60 is joined to the inner bottom surface 32a of the bottom plate 32. An upper edge 60f of the blocking plate 60 is separated from the ceiling surface 33a of the top plate 33. In other words, the upper edge 60f is not joined to the top plate 33. The upper edge 60f faces the top plate 33 in the vertical direction Z.

[0072] The dimension of the short edge of the blocking plate 60 is smaller than the dimension from the inner bottom surface 32a of the bottom plate 32 to the lower end of the gas exhaust pipe 24a. Therefore, the upper end edge 60f, which is the upper end of the blocking plate 60, is located lower in the vertical direction Z than the lower end of the exhaust port 52. The blocking plate 60 is in contact with a part of the periphery of the drain port 53. When the blocking plate 60 and the drain port 53 are viewed in the vertical direction Z, the second surface 60b of the blocking plate 60 is a tangent to the drain port 53. Therefore, it can be said that the second surface 60b of the blocking plate 60 is connected to the drain port 53.

[0073] The long edge of the blocking plate 60 extends in the second direction Y. Therefore, the long edge of the blocking plate 60 extends parallel to the long edge of the first partition portion 41 and the long edge of the second end plate 37. <effect> Next, the operation of this embodiment will be described along with the flows of the anode off-gas, cathode off-gas, mixed gas, and generated water. In Fig. 4, the flows of the anode off-gas, cathode off-gas, and mixed gas are indicated by solid arrows, and the flow of the generated water is indicated by dashed arrows.

[0074] The cathode off-gas that has flowed into the dilution chamber S12 flows through the first chamber S121 in the flow direction F, and then flows through the second chamber S122. In the second chamber S122, a portion of the cathode off-gas passes between the upper edge 60f of the blocking plate 60 and the ceiling surface 33a of the top plate 33, and then comes into contact with the inner surface 37a of the second end plate 37. This contact changes the flow direction of the cathode off-gas.

[0075] Also, part of the cathode off-gas contacts the first surface 60a of the blocking plate 60 while passing below the upper edge 60f of the blocking plate 60 in the vertical direction Z. This contact changes the flow direction of the cathode off-gas. Part of the cathode off-gas that contacts the first surface 60a flows toward the first edge 60c of the blocking plate 60. Then, part of the cathode off-gas passes between the inner surface 35a of the second side plate 35 and the first edge 60c, and then flows along the second surface 60b of the blocking plate 60 toward the first side plate 34.

[0076] Furthermore, a portion of the cathode off-gas that has come into contact with the first surface 60a flows toward the second edge 60d of the blocking plate 60. Then, a portion of the cathode off-gas passes between the inner surface 34a of the first side plate 34 and the second edge 60d, and then flows along the second surface 60b of the blocking plate 60 toward the second side plate 35. The cathode off-gas then flows toward the exhaust port 52.

[0077] The generated water in the retention chamber S11 flows into the dilution chamber S12 through the communication port G1 together with the flow of the anode off-gas. The generated water in the dilution chamber S12 flows on the inner bottom surface 32a together with the cathode off-gas in the flow direction F. For this reason, it can be said that the generated water flows on the inner bottom surface 32a in the flow direction F together with the cathode off-gas in the first chamber S121.

[0078] The produced water flowing from the first chamber S121 into the second chamber S122 and flowing on the inner bottom surface 32a is temporarily blocked by the blocking plate 60. Then, a part of the produced water blocked by the blocking plate 60 flows toward the first edge 60c of the blocking plate 60 together with the mixed gas. The produced water passes between the inner surface 35a of the second side plate 35 and the first edge 60c, and then flows along the second surface 60b of the blocking plate 60 toward the drain port 53. Then, the produced water that has passed between the inner surface 35a of the second side plate 35 and the first edge 60c together with the mixed gas is discharged from the drain port 53.

[0079] Further, a portion of the produced water blocked by the blocking plate 60 passes between the inner surface 34a and the second edge 60d of the first side plate 34 together with the mixed gas, and then flows along the second surface 60b of the blocking plate 60 toward the drain outlet 53. Then, the produced water that has passed between the inner surface 34a and the second edge 60d of the first side plate 34 together with the mixed gas is discharged from the drain outlet 53.

[0080] <Effects of the embodiment> The above embodiment has the following advantages. (1) The diluter 30 for a fuel cell system has a blocking plate 60. When the generated water flows on the inner bottom surface 32a toward the exhaust port 52 together with the flow of the mixed gas, the generated water is once blocked by the blocking plate 60. Therefore, the generated water is prevented from flowing toward the exhaust port 52, and the generated water is prevented from accumulating near the exhaust port 53 inside the diluter 30 for a fuel cell system. Then, a part of the mixed gas flows from the first surface 60a to the second surface 60b of the blocking plate 60 so as to go around the blocking plate 60. Then, the generated water flows toward the drain port 53 arranged downstream of the blocking plate 60 in the flow direction F. Then, the generated water is discharged from the drain port 53 to the outside of the diluter 30 for a fuel cell system. Therefore, the generated water introduced into the dilution chamber S12 is easily discharged from the drain port 53. Therefore, the generated water can be prevented from being discharged from the dilution chamber S12 together with the mixed gas.

[0081] (2) The blocking plate 60 is disposed in a position aligned with the drain outlet 53 in the flow direction F. With this, the generated water, once blocked by the blocking plate 60, can easily reach the drain outlet 53 when it flows around the blocking plate 60. Therefore, the generated water can be easily discharged from the drain outlet 53.

[0082] (3) The first edge 60c of the blocking plate 60 is separated from the inner surface 35a of the second side plate 35, and the second edge 60d is separated from the inner surface 34a of the first side plate 34. This allows the generated water once blocked by the blocking plate 60 to flow through two paths: between the first edge 60c and the inner surface 35a of the second side plate 35, and between the second edge 60d and the inner surface 34a of the first side plate 34. Therefore, when the generated water once blocked by the blocking plate 60 flows around the blocking plate 60, it becomes easier to reach the drain outlet 53. Therefore, the generated water can be easily discharged from the drain outlet 53.

[0083] (4) The upper edge 60f of the blocking plate 60 is located lower in the vertical direction Z than the lower end of the exhaust port 52. With this, even if the generated water is stirred up by the mixed gas, the stirred up generated water is less likely to reach the upper side in the vertical direction Z than the lower end of the exhaust port 52, compared to, for example, a case in which the upper edge 60f of the blocking plate 60 is located higher in the vertical direction Z than the lower end of the exhaust port 52. Therefore, the stirred up generated water is less likely to enter the gas exhaust pipe 24a. Therefore, it is possible to easily prevent the generated water from being discharged from the dilution chamber S12 together with the mixed gas.

[0084] In addition, generated water may accumulate without being discharged from the drainage port 53 and flowing to the vicinity of the exhaust port 52. Even if the volume of the accumulated generated water increases, the volume of the accumulated generated water is less likely to reach the lower end of the exhaust port 52, i.e., the lower end of the gas exhaust pipe 24a, compared to when the upper edge 60f of the blocking plate 60 is located above the lower end of the exhaust port 52 in the vertical direction Z. From the above, it is possible to make it difficult for the generated water introduced into the dilution chamber S12 to be discharged from the exhaust port 52.

[0085] (5) When looking at the exhaust port 52 in the flow direction F, the exhaust port 52 is disposed away from the drain port 53 in the second direction Y. This makes it difficult for the produced water to be carried to the exhaust port 52 by the flow of the mixed gas without being discharged from the drain port 53.

[0086] (6) The tip 240a of the gas exhaust pipe 24a is inserted into the dilution chamber S12. This makes it difficult for the generated water to enter the gas exhaust pipe 24a even if the generated water that has accumulated on the inner bottom surface 32a is stirred up by the mixed gas. This makes it easy to prevent the generated water from being discharged from the dilution chamber S12 together with the mixed gas.

[0087] (7) The blocking plate 60 is disposed in a position close enough to contact the edge of the drain outlet 53. With this, the generated water that is once blocked by the blocking plate 60 can be easily discharged from the drain outlet 53 after going around the blocking plate 60.

[0088] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0089] In the embodiment, the first edge 60c of the blocking plate 60 may not be separated from the second side plate 35. That is, the first edge 60c of the blocking plate 60 may be in contact with the inner surface 35a of the second side plate 35. In this case, the generated water once blocked by the blocking plate 60 may pass between the second edge 60d and the inner surface 34a of the first side plate 34 and flow toward the drain outlet 53. Also, the second edge 60d of the blocking plate 60 may not be separated from the first side plate 34. That is, the second edge 60d of the blocking plate 60 may be in contact with the inner surface 34a of the first side plate 34. In this case, the generated water once blocked by the blocking plate 60 may pass between the first edge 60c and the inner surface 35a of the second side plate 35 and flow toward the drain outlet 53.

[0090] In the embodiment, the blocking plate 60 does not have to be arranged in a position aligned with the drain outlet 53 in the flow direction F. Alternatively, the blocking plate 60 may be arranged in a position aligned with a part of the drain outlet 53 in the flow direction F.

[0091] In the embodiment, the blocking plate 60 does not have to extend parallel to the second end plate 37. That is, the shortest distance from the first edge 60c to the second end plate 37 of the blocking plate 60 does not have to be equal to the shortest distance from the second edge 60d to the second end plate 37. For example, the shortest distance from the first edge 60c to the second end plate 37 of the blocking plate 60 may be greater than the shortest distance from the second edge 60d to the second end plate 37, or the shortest distance from the first edge 60c to the second end plate 37 may be smaller than the shortest distance from the second edge 60d to the second end plate 37. In short, it is sufficient that the blocking plate 60 can block the flow of the generated water accumulated on the inner bottom surface 32a.

[0092] In the embodiment, the blocking plate 60 does not have to be disposed perpendicular to the inner bottom surface 32a. For example, the blocking plate 60 may be inclined so that the shortest distance from the lower edge 60e to the second end plate 37 is greater than the shortest distance from the upper edge 60f to the second end plate 37, or may be inclined so that the shortest distance from the lower edge 60e to the second end plate 37 is smaller than the shortest distance from the upper edge 60f to the second end plate 37.

[0093] In the embodiment, the upper edge 60f of the blocking plate 60 may be positioned at the same height as the lower end of the exhaust port 52, or may be positioned higher than the lower end of the exhaust port 52 in the vertical direction Z.

[0094] In the embodiment, when viewing the exhaust outlet 52 in the flow direction F, the exhaust outlet 52 does not have to be disposed at a distance from the drain outlet 53 in the second direction Y. In other words, when viewing the exhaust outlet 52 in the flow direction F, the exhaust outlet 52 may be disposed in a position aligned with the drain outlet 53 in the second direction Y.

[0095] In the above-described embodiment, the drain outlet 53 is not limited to a circular hole, and may be, for example, a rectangular hole. In short, it is only necessary that the drain outlet 53 is formed in the bottom plate 32 of the container 31. The fuel cell may be composed of a single fuel cell. [Explanation of symbols]

[0096] 11...fuel cell stack as a fuel cell, 30...diluter for fuel cell system, 32a...inner bottom surface, 34a, 35a, 36a, 37a...inner surfaces as inner surfaces, 52...exhaust port, 53...drain port, 60...blocking plate, 60c...first edge, 60d...second edge, 60f...upper edge which is the upper end portion, F...flow direction, S11...storage chamber, S12...dilution chamber, Z...vertical direction.

Claims

1. a retention chamber into which an anode off-gas discharged from the fuel cell and containing generated water flows; a dilution chamber into which a cathode off-gas discharged from the fuel cell and containing generated water flows, the dilution chamber into which the anode off-gas discharged from the retention chamber and the cathode off-gas are mixed; a drain port that opens to an inner bottom surface of the dilution chamber that defines the dilution chamber and drains generated water that has accumulated on the inner bottom surface; a diluter for a fuel cell system, the dilution chamber being defined, the dilution chamber being open to an inner surface of the dilution chamber intersecting the inner bottom surface, and an exhaust port being opened to exhaust a mixed gas of the anode off-gas and the cathode off-gas, If the direction in which the cathode off-gas that has flowed into the dilution chamber flows toward the exhaust port is defined as a flow direction, The drain outlet is disposed upstream of the exhaust outlet in the flow direction, A blocking plate for blocking the generated water is disposed on the inner bottom surface, The blocking plate is disposed upstream of the drain outlet in the flow direction, and at least one of both end edges of the blocking plate is spaced apart from the inner surface.

2. 2. The dilution device for a fuel cell system according to claim 1, wherein the blocking plate is disposed at a position aligned with at least a portion of the drain port in the flow direction.

3. 3. The dilution device for a fuel cell system according to claim 1, wherein both end edges of the blocking plate are spaced apart from the inner surface.

4. 4. The dilution device for a fuel cell system according to claim 2, wherein an upper end of the blocking plate is positioned vertically lower than a lower end of the exhaust port.

5. 5. The dilution device for a fuel cell system according to claim 1, wherein the exhaust port is positioned away from the drain port when viewed in the flow direction.

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