Fuel cell units for industrial vehicles

Abstract

To provide a fuel cell unit for an industrial vehicle capable of suppressing leakage of generated water from a water storage tank to a gas-liquid separator.SOLUTION: A fuel cell unit includes a gas-liquid separator 30, a water storage tank 50, and a drain port 70. The drain port 70 opens to the inner bottom surface 31a of the gas-liquid separator 30 and opens to a ceiling surface 53a of the water storage tank 50. The drain port 70 allows an internal space S of the gas-liquid separator 30 and an internal space S1 of the water storage tank 50 to communicate in the vertical direction. A wall portion 60 divides the surface F of generated water in the internal space S1 of the water storage tank 50 into a first region R1 facing the drain port 70 and a second region R2 which is another region. The fuel cell unit also has a communicating portion 71 that communicates the first region R1 and the second region R2.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a fuel cell unit for an industrial vehicle. [Background technology]

[0002] The fuel cell unit for an industrial vehicle has a fuel cell. The fuel cell generates electric power to be supplied to a vehicle load of the industrial vehicle. The fuel cell generates electric power by chemically reacting hydrogen supplied to the anode with oxygen supplied to the cathode. The fuel cell generates water by chemically reacting hydrogen with oxygen.

[0003] The fuel cell unit for industrial vehicles has a gas-liquid separator and a water storage tank. The gas-liquid separator separates water contained in the anode off-gas. The gas-liquid separator is disposed vertically above the water storage tank.

[0004] The internal space of the gas-liquid separator and the internal space of the water storage tank are connected by a drainage section. The water separated by the gas-liquid separator falls through the drainage section into the water storage tank. The water storage tank stores the water separated by the gas-liquid separator.

[0005] For example, Patent Document 1 discloses a method for suppressing leakage of generated water from a water storage tank. The fuel cell device of Patent Document 1 includes a water tank as an example of a water storage tank. The water tank is connected to a fuel cell. The fuel cell device also includes a first drain pipe, a second drain pipe, a third drain pipe, and a fourth drain pipe.

[0006] The upper end of the first drain pipe and the upper end of the second drain pipe are connected to a pipe connection port provided in the left region of the fuel cell. The lower end of the first drain pipe and the lower end of the second drain pipe are connected to a pipe connection port provided in the right region of the water tank. The upper end of the third drain pipe and the upper end of the fourth drain pipe are connected to a pipe connection port provided in the right region of the fuel cell. The lower end of the third drain pipe and the lower end of the fourth drain pipe are connected to a pipe connection port provided in the left region of the water tank.

[0007] For example, if the fuel cell device is tilted so that its left side is down and its right side is up, an air pocket is created at the upper end of the right region in the water tank. Then, the pipe connection port in the right region of the water tank opens into the air pocket. Therefore, water in the water tank does not flow into the first drain pipe and the second drain pipe. Therefore, water does not leak from the water tank into the left region of the fuel cell, which is below the liquid level. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2002-63920 A Summary of the Invention [Problem to be solved by the invention]

[0009] When acceleration occurs during the movement of an industrial vehicle, the water tank does not tilt, but the liquid level of the produced water in the internal space of the water tank tilts. As a result, there are areas where the liquid level is higher than before the acceleration occurred. The fuel cell device of Patent Document 1 does not take into consideration the tilt of the liquid level when acceleration occurs. Therefore, there is a risk that water will flow into the drain pipe at the areas where the liquid level is high and leak from the water tank to the fuel cell. [Means for solving the problem]

[0010] The fuel cell unit for industrial vehicles that solves the above problems comprises a fuel cell, a gas-liquid separator into which anode off-gas discharged from the fuel cell flows and which separates the produced water contained in the anode off-gas from the anode off-gas, a water storage tank that stores the produced water separated by the gas-liquid separator, and a drain port that opens onto the inner bottom surface of the gas-liquid separator and onto the ceiling surface of the water storage tank, the drain port connecting the internal space of the gas-liquid separator to the internal space of the water storage tank in the vertical direction, and is a fuel cell unit for industrial vehicles that is mounted on the body of the industrial vehicle, and has a wall portion that divides the liquid level of the produced water in the internal space of the water storage tank into an opposing area facing the drain port and another area different from the opposing area, and has a communication portion that connects the opposing area to the other area.

[0011] According to this, when the industrial vehicle starts, stops, and turns, acceleration occurs in the fuel cell unit. As acceleration occurs, the liquid level fluctuates in the internal space of the water storage tank, causing the liquid level to tilt. At this time, the liquid level is separated into an opposing area and other areas by the wall portion. Therefore, compared to when the liquid level is not separated, the heights of the liquid level in the opposing area and the liquid level in the other areas are lower. As a result, it is possible to prevent the generated water stored in the water storage tank from leaking into the gas-liquid separator through the drain outlet. In addition, since the opposing area and the other area are connected by the communication portion, the liquid level heights do not differ between the opposing area and the other area.

[0012] In a fuel cell unit for an industrial vehicle, the wall portion may extend from the ceiling surface toward a bottom surface of the water tank, and the communication portion may be a gap defined between a lower end of the wall portion and the bottom surface of the tank.

[0013] According to this, when no acceleration is occurring, the liquid level in the opposing region and the liquid level in the other region can be made to be the same height by the communication portion, which means that it is possible to prevent the liquid levels in the opposing region and the other region from being unevenly spaced.

[0014] In a fuel cell unit for an industrial vehicle, the wall portion may be cylindrical and surround the drain outlet. In industrial vehicles, acceleration occurs in all directions, including the front-rear and width directions of the vehicle body. At this time, the drain outlet is surrounded by walls in all directions. This makes it possible to prevent the liquid level in the opposing area from becoming high in all directions.

[0015] In a fuel cell unit for an industrial vehicle, the wall portion may include a first wall portion and a second wall portion that sandwich the drain outlet in a front-rear direction of the industrial vehicle. This allows the liquid level to be divided in the front-rear direction of the industrial vehicle. Effect of the Invention

[0016] The present invention can suppress leakage of produced water from the water storage tank to the gas-liquid separator. [Brief description of the drawings]

[0017] [Figure 1] FIG. [Diagram 2] FIG. 1 is a schematic diagram showing a fuel cell unit for an industrial vehicle. [Diagram 3] FIG. 2 is a perspective view showing a gas-liquid separator and a water tank. [Figure 4] 4 is a cross-sectional view taken along line 4-4 in FIG. 3, showing the gas-liquid separator and the water tank. [Diagram 5] 5 is a cross-sectional view taken along line 5-5 in FIG. 3, showing the gas-liquid separator and the water tank. [Figure 6] 5A and 5B are diagrams illustrating the functions of a gas-liquid separator and a water tank. [Figure 7] FIG. 11 is a perspective view showing another example of a gas-liquid separator and a water storage tank. [Figure 8] 8 is a cross-sectional view taken along line 8-8 in FIG. 7, showing the gas-liquid separator and the water tank. [Figure 9] FIG. 11 is a cross-sectional view showing another example of the gas-liquid separator and the water tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, one embodiment of a fuel cell unit for an industrial vehicle will be described with reference to Figs. <Fuel Cell Forklift 100> As shown in Fig. 1, a fuel cell forklift 100 as an industrial vehicle has a vehicle body 101 and a vehicle load 102. In the following description, front, rear, left, right, top and bottom are based on the fuel cell forklift 100. The front-rear direction X can also be referred to as the traveling direction of the fuel cell forklift 100. The left-right direction Y can also be referred to as the vehicle width direction of the fuel cell forklift 100. The up-down direction Z can also be referred to as the height direction of the fuel cell forklift 100.

[0019] Examples of the vehicle load 102 are a travel motor 103 and a load motor 104. The travel motor 103 drives drive wheels 105 of the vehicle body 101. The load motor 104 drives a load device 106. The vehicle body 101 has an accommodation section 107 for the fuel cell unit 10. The fuel cell unit 10 is mounted on the vehicle body 101 by being accommodated in the accommodation section 107.

[0020] <Fuel Cell Unit 10> 2, the fuel cell unit 10 includes a fuel cell stack 11, a hydrogen tank 12, and an air compressor 13. The fuel cell unit 10 also includes an anode gas supply path 16, a cathode gas supply path 17, an anode off-gas discharge path 18, and a cathode off-gas discharge path 19. The fuel cell unit 10 also includes a gas-liquid separator 30, a water tank 50, and a drain port 70.

[0021] <Fuel Cell Stack 11> 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.

[0022] <Hydrogen tank 12, air compressor 13> The hydrogen tank 12 stores hydrogen gas. The air compressor 13 compresses air. <Anode gas supply path 16> 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.

[0023] <Cathode gas supply passage 17> 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.

[0024] <Anode off-gas exhaust passage 18> The anode off-gas discharge path 18 connects an anode (not shown) of the fuel cell stack 11 to the gas-liquid separator 30. The anode off-gas discharged from the anode of the fuel cell stack 11 flows through the anode off-gas discharge path 18 from the anode of the fuel cell stack 11 toward the gas-liquid separator 30. The anode off-gas mainly contains unreacted hydrogen gas in the fuel cell stack 11 and water generated when hydrogen reacts with oxygen.

[0025] <Cathode off-gas exhaust passage 19> The cathode offgas discharge path 19 connects a cathode (not shown) of the fuel cell stack 11 to the gas-liquid separator 30. The cathode offgas flows through the cathode offgas discharge path 19 from the fuel cell stack 11 toward the gas-liquid separator 30. The cathode offgas mainly contains air containing unreacted oxygen in the fuel cell stack 11 and water generated when hydrogen and oxygen react with each other.

[0026] <Gas-liquid separator 30> The gas-liquid separator 30 receives the cathode off-gas discharged from the fuel cell stack 11. The gas-liquid separator 30 separates the generated water contained in the cathode off-gas from the cathode off-gas. The gas-liquid separator 30 also receives the anode off-gas discharged from the fuel cell stack 11. The gas-liquid separator 30 separates the generated water contained in the anode off-gas from the anode off-gas.

[0027] As shown in FIGS. 3, 4, and 5, the gas-liquid separator 30 has an anode offgas inlet 38, a cathode offgas inlet 39, a gas exhaust port 40, and a first communication port 41. The gas-liquid separator 30 has a rectangular parallelepiped shape with its long sides extending in the front-rear direction X. The gas-liquid separator 30 has a rectangular parallelepiped shape with its short sides extending in the left-right direction Y.

[0028] The gas-liquid separator 30 has a bottom plate 31 and a top plate 32 facing each other in the up-down direction Z. Each of the bottom plate 31 and the top plate 32 is a rectangular plate. The long edges of the bottom plate 31 and the top plate 32 extend in the front-rear direction X. The short edges of the bottom plate 31 and the top plate 32 extend in the left-right direction Y. The distance between the bottom plate 31 and the top plate 32 in the up-down direction Z may be constant in the front-rear direction X and the left-right direction Y, or may change from one end to the other end in at least one of the front-rear direction X and the left-right direction Y.

[0029] The bottom plate 31 has an inner bottom surface 31a on one side in the plate thickness direction, and an outer bottom surface 31b on the other side in the plate thickness direction. The plate thickness direction of the bottom plate 31 coincides with the up-down direction Z. The top plate 32 has an inner surface 32a on one side in the plate thickness direction, and an outer surface 32b on the other side in the plate thickness direction. The plate thickness direction of the top plate 32 coincides with the up-down direction Z. The inner bottom surface 31a of the bottom plate 31 and the inner surface 32a of the top plate 32 face each other in the up-down direction Z.

[0030] The gas-liquid separator 30 has a first side plate 34 and a second side plate 35 facing each other in the left-right 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 front-rear direction X. The short edges of the first side plate 34 and the second side plate 35 extend in the up-down direction Z.

[0031] The gas-liquid separator 30 has a first end plate 36 and a second end plate 37 facing each other in the front-rear 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 left-right direction Y. The short edges of the first end plate 36 and the second end plate 37 extend in the up-down direction Z.

[0032] The bottom plate 31, the top plate 32, the first side plate 34, the second side plate 35, the first end plate 36, and the second end plate 37 are plates that constitute the gas-liquid separator 30. The longitudinal direction of the gas-liquid separator 30 is the direction in which the long edges of the bottom plate 31, the top plate 32, the first side plate 34, and the second side plate 35 extend.

[0033] The internal space S of the gas-liquid separator 30 is defined by a bottom plate 31 , a top plate 32 , a first side plate 34 , a second side plate 35 , a first end plate 36 , and a second end plate 37 . <Anode off-gas inlet 38> The anode offgas inlet 38 allows the anode offgas discharged from the fuel cell stack 11 to flow into the gas-liquid separator 30. The anode offgas inlet 38 is connected to the anode offgas discharge path 18. The anode offgas inlet 38 is disposed in the top plate 32. The anode offgas inlet 38 penetrates the top plate 32 in the plate thickness direction. The position of the anode offgas inlet 38 on the top plate 32 is arbitrary. The generated water contained in the anode offgas is separated from the anode offgas by its own weight in the internal space S of the gas-liquid separator 30. The separated generated water accumulates on the inner bottom surface 31a of the bottom plate 31.

[0034] <Cathode off-gas inlet 39> The cathode offgas inlet 39 allows the cathode offgas discharged from the fuel cell stack 11 to flow into the gas-liquid separator 30. The cathode offgas inlet 39 is connected to the cathode offgas discharge path 19. The cathode offgas inlet 39 is disposed in the first end plate 36. The cathode offgas inlet 39 penetrates the first end plate 36 in the plate thickness direction. The position of the cathode offgas inlet 39 in the first end plate 36 is arbitrary. The generated water contained in the cathode offgas is separated from the cathode offgas by its own weight in the internal space S of the gas-liquid separator 30. The separated generated water accumulates on the inner bottom surface 31a of the bottom plate 31.

[0035] <Gas exhaust port 40> The gas exhaust port 40 is disposed in the second end plate 37. The gas exhaust port 40 penetrates the second end plate 37 in the plate thickness direction. The cathode off-gas and the anode off-gas are mixed in the internal space S of the gas-liquid separator 30. This mixing causes the anode off-gas to be diluted by the cathode off-gas. The exhaust gas obtained by mixing the anode off-gas and the cathode off-gas in the gas-liquid separator 30 is discharged via the gas exhaust port 40. Therefore, the gas-liquid separator 30 also serves as a diluter for the anode off-gas.

[0036] <1st communication port 41> The first communication port 41 is disposed in the bottom plate 31. The first communication port 41 is disposed closer to the second end plate 37 than the center in the longitudinal direction of the bottom plate 31. The first communication port 41 is disposed closer to the second side plate 35 than the center in the lateral direction of the bottom plate 31. The first communication port 41 penetrates the bottom plate 31 in the plate thickness direction. The first communication port 41 enables generated water that accumulates on the inner bottom surface 31a of the bottom plate 31 to be discharged to the outside of the gas-liquid separator 30.

[0037] <Water tank 50> The water storage tank 50 stores the product water separated in the gas-liquid separator 30 . The water tank 50 has a tank body 51 , a second communication port 59 , a wall portion 60 , and a discharge port 61 .

[0038] The tank body 51 has a rectangular parallelepiped shape with its long sides extending in the front-rear direction X. The tank body 51 has a rectangular parallelepiped shape with its short sides extending in the left-right direction Y. The tank body 51 has a tank bottom plate 52 and a tank top plate 53 that face each other in the up-down direction Z. The tank bottom plate 52 and the tank top plate 53 are each shaped like a rectangular plate. The long edges of the tank bottom plate 52 and the tank top plate 53 extend in the front-rear direction X. The short edges of the tank bottom plate 52 and the tank top plate 53 extend in the left-right direction Y. The distance between the tank bottom plate 52 and the tank top plate 53 in the up-down direction Z may be constant in the front-rear direction X and the left-right direction Y, or may change from one end to the other end in at least one of the front-rear direction X and the left-right direction Y.

[0039] The tank bottom plate 52 has a tank bottom surface 52a on one side in the plate thickness direction. The tank top plate 53 has a ceiling surface 53a on one side in the plate thickness direction and a top surface 53b on the other side in the plate thickness direction. The outer bottom surface 31b of the gas-liquid separator 30 is in contact with the top surface 53b of the tank top plate 53. The internal space S of the gas-liquid separator 30 and the internal space S1 of the water storage tank 50 are separated by the bottom plate 31 and the tank top plate 53. The plate thickness direction of the tank top plate 53 coincides with the vertical direction Z. The tank bottom surface 52a of the tank bottom plate 52 and the ceiling surface 53a of the tank top plate 53 face each other in the vertical direction Z.

[0040] The tank body 51 has a first tank side plate 54 and a second tank side plate 55 facing each other in the left-right direction Y. Each of the first tank side plate 54 and the second tank side plate 55 is a rectangular plate. The long edges of the first tank side plate 54 and the second tank side plate 55 extend in the front-rear direction X. The short edges of the first tank side plate 54 and the second tank side plate 55 extend in the up-down direction Z.

[0041] The tank body 51 has a first tank end plate 56 and a second tank end plate 57 that face each other in the front-rear direction X. The first tank end plate 56 and the second tank end plate 57 are rectangular plates. The long edges of the first tank end plate 56 and the second tank end plate 57 extend in the up-down direction Z. The short edges of the first tank end plate 56 and the second tank end plate 57 extend in the left-right direction Y.

[0042] The internal space S1 of the water storage tank 50, more specifically, the internal space S1 of the tank body 51, is defined by a tank bottom plate 52, a tank top plate 53, a first tank side plate 54, a second tank side plate 55, a first tank end plate 56, and a second tank end plate 57. The tank bottom plate 52, the tank top plate 53, the first tank side plate 54, the second tank side plate 55, the first tank end plate 56, and the second tank end plate 57 are plates that constitute the tank body 51.

[0043] <Second communication port 59> The second communication port 59 is disposed in the tank top plate 53. The second communication port 59 is disposed closer to the second tank end plate 57 than the center in the longitudinal direction of the tank top plate 53. The second communication port 59 is disposed in the center in the lateral direction of the tank top plate 53. The second communication port 59 penetrates the tank top plate 53 in the plate thickness direction. The second communication port 59 opens to the ceiling surface 53a of the tank top plate 53. The second communication port 59 overlaps with the first communication port 41 of the gas-liquid separator 30 in the up-down direction Z.

[0044] <Wall part 60> The wall portion 60 is cylindrical. The wall portion 60 extends from the ceiling surface 53a of the tank top plate 53 toward the tank bottom surface 52a of the tank bottom plate 52. It can be said that the wall portion 60 is tubular surrounding the second communication port 59. The inner peripheral edge of the wall portion 60 is along the opening edge of the second communication port 59. The tip surface 60a of the wall portion 60 is the lower end of the wall portion 60. The tip surface 60a of the wall portion 60 is located above the tank bottom surface 52a of the tank bottom plate 52. The tip surface 60a of the wall portion 60 is separated from the tank bottom surface 52a.

[0045] <Exhaust port 61> The discharge port 61 is disposed in the second tank end plate 57. The discharge port 61 penetrates the second tank end plate 57 in the plate thickness direction. The produced water stored in the water storage tank 50 is periodically discharged from the discharge port 61.

[0046] <Drain port 70> The drain outlet 70 is formed by overlapping the first communication port 41 of the gas-liquid separator 30 and the second communication port 59 of the water storage tank 50 in the vertical direction Z. The drain outlet 70 communicates the internal space S of the gas-liquid separator 30 and the internal space S1 of the water storage tank 50 in the vertical direction Z. The drain outlet 70 opens to the inner bottom surface 31a of the gas-liquid separator 30 and also opens to the ceiling surface 53a of the water storage tank 50.

[0047] <Overall view of water tank 50> As described above, the wall portion 60 extends from the ceiling surface 53a of the tank top plate 53 toward the tank bottom surface 52a of the tank bottom plate 52. The wall portion 60 also surrounds the second communication port 59. The wall portion 60 extends from the opening edge of the second communication port 59. Therefore, it can be said that the wall portion 60 extends from the opening edge of the drainage port 70.

[0048] The produced water accumulated on the inner bottom surface 31a of the gas-liquid separator 30 is discharged through the drain port 70 into the internal space S1 of the water storage tank 50. The produced water discharged into the internal space S1 of the water storage tank 50 is stored on the tank bottom surface 52a. When the liquid level F of the produced water is positioned above the tip surface 60a of the wall portion 60, the liquid level F is divided into a first region R1 inside the wall portion 60 and a second region R2 other than the first region R1. When the liquid level F is viewed in the vertical direction Z, the first region R1 is circular. When the liquid level F is viewed in the vertical direction Z, the second region R2 surrounds the first region R1.

[0049] The wall portion 60 divides the liquid level F of the produced water into a first region R1 and a second region R2 in the internal space S1 of the water storage tank 50. The first region R1 is an area of ​​the liquid level F that faces the drain outlet 70. The first region R1 has a circular shape of the same size as the opening shape of the drain outlet 70. The second region R2 is the other region different from the first region R1.

[0050] The tank length L of the tank body 51 is the distance in the front-rear direction X between the inner surface of the first tank end plate 56 and the inner surface of the second tank end plate 57. The opening width W of the wall portion 60 is the distance in the front-rear direction X between the inner circumferential surfaces of the wall portion 60 that face each other in the front-rear direction X. Therefore, the opening width W is the same as the distance K in the front-rear direction X of the first region R1. This distance K of the first region R1 is shorter than the tank length L.

[0051] The tip surface 60a of the wall portion 60 is separated from the tank bottom surface 52a of the tank bottom plate 52. While the wall portion 60 divides the liquid surface F, it does not divide the internal space S1 of the water storage tank 50 into a plurality of spaces. Therefore, the first region R1 and the second region R2 are in communication with each other. Therefore, the generated water stored in the internal space S1 of the water storage tank 50 is not stored in a plurality of separate spaces. Between the tip surface 60a of the wall portion 60 and the tank bottom surface 52a of the tank bottom plate 52, a gap is formed that connects the first region R1 and the second region R2. This gap is a communication portion 71 that connects the first region R1 and the second region R2. Therefore, the fuel cell unit 10 has the communication portion 71 that connects the first region R1 and the second region R2. The communication portion 71 is a gap defined between the tip surface 60 a of the wall portion 60 and the tank bottom surface 52 a of the tank bottom plate 52 .

[0052] The height H1 of the communication portion 71 is the dimension in the up-down direction Z between the tip surface 60a of the wall portion 60 and the tank bottom surface 52a of the tank bottom plate 52. If the height H1 of the communication portion 71 is too low, it becomes difficult for the generated water to move between the first region R1 and the second region R2. For this reason, the height H1 of the communication portion 71 is preferably set to 20 mm or more.

[0053] <effect> Acceleration occurs when the fuel cell forklift 100 starts moving. Then, acceleration occurs in the front-rear direction X, causing the liquid level F in the internal space S1 of the water storage tank 50 to fluctuate and tilt.

[0054] As indicated by the two-dot chain line in Fig. 6, the height of the liquid level F in the absence of the wall portion 60 is determined by the tank length L. As indicated in Fig. 6, the height of the liquid level F in the first region R1 inside the wall portion 60 is determined by the distance K. The distance K is shorter than the tank length L. Therefore, the height of the liquid level F in the first region R1 is lower than the height of the liquid level F in the absence of the wall portion 60.

[0055] According to the above embodiment, the following effects can be obtained. (1) The water storage tank 50 has a wall portion 60 extending from the tank top plate 53. The wall portion 60 divides the liquid level F into a first region R1 and a second region R2. The distance K of the first region R1 is shorter than the tank length L. Therefore, when the liquid level F is tilted, the height of the liquid level F in the first region R1 can be made lower than the height of the liquid level F in the absence of the wall portion 60. As a result, the generated water in the water storage tank 50 can be prevented from leaking through the drain port 70 to the gas-liquid separator 30. In order to prevent the generated water from leaking from the water storage tank 50 to the gas-liquid separator 30, the fuel cell unit 10 employs only the wall portion 60. In order to prevent the generated water from leaking, measures such as complex arrangement of pipes connecting the gas-liquid separator 30 and the water storage tank 50 are not required, and as a result, the fuel cell unit 10 can be prevented from becoming large in size.

[0056] (2) The wall portion 60 extends from the ceiling surface 53a of the tank top plate 53 toward the tank bottom surface 52a of the tank bottom plate 52. The communication portion 71 is a gap defined between the tip surface 60a of the wall portion 60 and the tank bottom surface 52a. When no acceleration is occurring, the communication portion 71 allows the liquid level F in the first region R1 and the liquid level F in the second region R2 to be at the same height. In other words, it is possible to prevent the height of the liquid level F from being uneven between the first region R1 and the second region R2.

[0057] (3) The wall 60 is cylindrical and surrounds the drainage outlet 70. In the fuel cell forklift 100, acceleration occurs in all directions, including the front-rear direction X and the left-right direction Y of the vehicle body 101. At this time, the drainage outlet 70 is surrounded in all directions by the wall 60. Therefore, even if acceleration occurs in all directions, the liquid level F in the first region R1 can be prevented from rising in all directions. Therefore, even if acceleration occurs in any direction, leakage of the generated water from the water storage tank 50 to the gas-liquid separator 30 can be prevented.

[0058] (4) The wall portion 60 extends from the ceiling surface 53a of the tank top plate 53 toward the tank bottom surface 52a. That is, the wall portion 60 is provided in the internal space S1 of the water storage tank 50. The wall portion 60 can be used to suppress leakage of the produced water from the water storage tank 50 to the gas-liquid separator 30. Therefore, leakage of the produced water from the water storage tank 50 to the gas-liquid separator 30 can be suppressed without providing an additional component outside the water storage tank 50. Therefore, leakage of the produced water from the water storage tank 50 to the gas-liquid separator 30 can be suppressed without increasing the size of the water storage tank 50.

[0059] (5) The gas-liquid separator 30 is disposed on the tank top plate 53. The drain port 70 is formed by overlapping the first communication port 41 formed on the bottom plate 31 of the gas-liquid separator 30 and the second communication port 59 formed on the tank top plate 53 of the water storage tank 50. Therefore, compared with the case where the internal space S of the gas-liquid separator 30 and the internal space S1 of the water storage tank 50 are connected by a pipe or the like, the dimension in the vertical direction Z including the gas-liquid separator 30 and the water storage tank 50 can be made smaller. And, even in a structure in which only the bottom plate 31 and the tank top plate 53 are interposed between the internal space S of the gas-liquid separator 30 and the internal space S1 of the water storage tank 50, the wall portion 60 can suppress leakage of generated water from the water storage tank 50 to the gas-liquid separator 30. In other words, even if the dimension in the vertical direction Z including the gas-liquid separator 30 and the water storage tank 50 is made smaller, leakage of generated water from the water storage tank 50 to the gas-liquid separator 30 can be suppressed.

[0060] (6) The wall portion 60 is provided along the opening edge of the drain outlet 70. Therefore, the size of the first region R1 when the liquid level F is viewed in the up-down direction Z can be made the same as the size of the drain outlet 70. Therefore, when the liquid level F is tilted, the height of the first region R1 can be lowered.

[0061] (7) The wall portion 60 is provided to suppress leakage of the generated water from the water storage tank 50 to the gas-liquid separator 30. For this reason, it is not necessary to adjust the positions of the gas exhaust port 40 and the cathode off-gas inlet 39 so as to prevent the generated water from being discharged outside the gas-liquid separator 30.

[0062] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction. As shown in FIGS. 7 and 8, the fuel cell unit 10 may have a first wall portion 81 and a second wall portion 82.

[0063] Each of the first wall portion 81 and the second wall portion 82 has a rectangular plate shape. Each of the first wall portion 81 and the second wall portion 82 extends from the ceiling surface 53a of the tank top plate 53 toward the tank bottom surface 52a. Each of the first wall portion 81 and the second wall portion 82 spans the first tank side plate 54 and the second tank side plate 55. In other words, the first wall portion 81 and the second wall portion 82 are provided over the entire tank body 51 in the left-right direction Y.

[0064] The first wall portion 81 and the second wall portion 82 sandwich the drain outlet 70 in the front-to-rear direction X. The first wall portion 81 has a first opposing surface 81a on one surface in the plate thickness direction. The second wall portion 82 has a second opposing surface 82a on one surface in the plate thickness direction. The first opposing surface 81a and the second opposing surface 82a face each other in the front-to-rear direction X. The first opposing surface 81a follows the opening edge of the drain outlet 70. The second opposing surface 82a follows the opening edge of the drain outlet 70.

[0065] A lower end 81b of the first wall portion 81 and a lower end 82b of the second wall portion 82 are each located above a tank bottom surface 52a of the tank bottom plate 52. The communication portion 83 is defined between the lower ends 81b and 82b and the tank bottom surface 52a.

[0066] In this configuration, the first region R1 as an opposing region opposing the drain outlet 70 is formed between the first wall portion 81, the second wall portion 82, the first tank side plate 54, and the second tank side plate 55. The distance K of the first region R1 is the same as in the embodiment, but the dimension of the first region R1 in the left-right direction Y is longer than in the embodiment. The second region R2 as the other region is formed between the first wall portion 81, the first tank end plate 56, the first tank side plate 54, and the second tank side plate 55. The third region R3 as another other region is formed between the second wall portion 82, the second tank end plate 57, the first tank side plate 54, and the second tank side plate 55.

[0067] The first wall portion 81 and the second wall portion 82 divide the liquid level F of the produced water in the internal space S1 of the water storage tank 50 into a first region R1 as an opposing region facing the drain outlet 70, and a second region R2 and a third region R3 as the other regions.

[0068] The number of walls may be changed, and the number of other regions may be changed as appropriate. 7 and 8, the first wall portion 81 and the second wall portion 82 do not have to span the first tank side plate 54 and the second tank side plate 55. In other words, the first wall portion 81 and the second wall portion 82 do not have to be provided over the entirety of the tank body 51 in the left-right direction Y. In this case, the opposing region is the first region R1 between the first wall portion 81 and the second wall portion 82.

[0069] 7 and 8, at least one of the first wall portion 81 and the second wall portion 82 may be spaced apart in the front-rear direction X from the opening edge of the drain outlet 70. However, in order to prevent the distance K from becoming too long, it is preferable that the distance from the opening edge be set to 150 mm or less.

[0070] 9, the wall portion 60 may extend from the tank bottom surface 52a. In this case, the tip surface 60a of the wall portion 60 is located at the upper end of the wall portion 60. The tip surface 60a of the wall portion 60 is located below the ceiling surface 53a of the tank top plate 53. The communication portion 71 is defined between the tip surface 60a of the wall portion 60 and the ceiling surface 53a of the tank top plate 53.

[0071] The inner peripheral edge of the wall portion 60 does not have to be aligned with the opening edge of the drain outlet 70. In this case, the inner peripheral edge of the wall portion 60 is spaced apart from the opening edge of the drain outlet 70. However, in order to prevent the distance K from becoming too long, it is preferable that the distance from the opening edge be set to 150 mm or less.

[0072] The gas outlet 40 of the gas-liquid separator 30 may be disposed in the top plate 32 . The positions of the anode off-gas inlet 38 and the cathode off-gas inlet 39 of the gas-liquid separator 30 may be changed.

[0073] Only the anode off-gas may flow into the gas-liquid separator 30. In this case, it is preferable that the fuel cell unit 10 includes a diluter in addition to the gas-liquid separator 30. The cathode off-gas discharged from the fuel cell stack 11 is introduced into the diluter. The diluter dilutes the anode off-gas discharged from the gas-liquid separator 30 with the cathode off-gas.

[0074] The height H1 of the communication portion 71 may be less than 20 mm. The wall portion 60 may be in the shape of a polygonal cylinder. In this case, it is preferable that the drain outlet 70 is in the shape of a polygonal hole so that the opening edge of the drain outlet 70 fits along the inner peripheral edge of the wall portion 60.

[0075] A communication pipe may be interposed between the bottom plate 31 of the gas-liquid separator 30 and the tank top plate 53 of the water storage tank 50. In this case, the drain outlet 70 may be formed by overlapping the first communication port 41 of the bottom plate 31, the second communication port 59 of the tank top plate 53, and the communication pipe in the vertical direction Z.

[0076] The fuel cell may be composed of a single fuel cell. The industrial vehicle may be a towing vehicle used for transporting cargo, an order picker used for picking operations, or the like.

[0077] The technical ideas that can be understood from the above-described embodiment and modified examples will be described. The inner peripheral edge of the wall portion extends beyond the opening edge of the drain outlet. [Explanation of symbols]

[0078] F...liquid level, R1...first region as opposing region, R2...second region as other region, R3...third region as other region, S, S1...internal space, 10...fuel cell unit, 11...fuel cell stack as fuel cell, 30...gas-liquid separator, 31a...inner bottom surface, 50...water tank, 52a...tank bottom surface, 53a...ceiling surface, 60...wall portion, 60a...tip surface as lower end, 70...drain outlet, 71, 83...communicating portion, 81...first wall portion, 81b...lower end, 82...second wall portion, 82b...lower end, 100...fuel cell forklift, 101...vehicle body.

Claims

1. A fuel cell; a gas-liquid separator into which an anode off-gas discharged from the fuel cell flows and which separates generated water contained in the anode off-gas from the anode off-gas; a water storage tank for storing the generated water separated by the gas-liquid separator; a drain port that opens to an inner bottom surface of the gas-liquid separator and also opens to a ceiling surface of the water storage tank, the drain port vertically connecting an internal space of the gas-liquid separator and an internal space of the water storage tank; and the fuel cell unit for an industrial vehicle is mounted on a body of the industrial vehicle, A wall portion is provided to divide the liquid surface of the produced water in the internal space of the water storage tank into an opposing area facing the drain outlet and another area different from the opposing area, A fuel cell unit for an industrial vehicle, comprising a communication portion that connects the opposing region with the other region.

2. The wall portion extends from the ceiling surface toward a bottom surface of the water storage tank, 2. The fuel cell unit for an industrial vehicle according to claim 1, wherein the communication portion is a gap defined between a lower end of the wall portion and a bottom surface of the tank.

3. 3. The fuel cell unit for an industrial vehicle according to claim 1, wherein the wall portion is tubular and surrounds the drain outlet.

4. 3. The fuel cell unit for an industrial vehicle according to claim 1, wherein the wall portion includes a first wall portion and a second wall portion that sandwich the drain outlet in a front-rear direction of the industrial vehicle.

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