Fuel cell unit

Abstract

To provide a fuel cell unit in which a coolant can be suppressed from being continuously accumulated in an in-frame region.SOLUTION: An assembly member 11 of a fuel cell unit 10 includes a base plate 12, a liquid-proof wall 20 protruding like a frame from a top face 12a of the base plate 12, and a discharge tank 40 disposed below the base plate 12. As seen from above, a forward route 51, a backward route 52, a connection flow path 53, a pump 32, an intercooler 33, an ion exchanger 34, and a reserve tank 35 are disposed in an in-frame region R2 surrounded by the liquid-proof wall 20. A first drain port 12c and a second drain port 12d communicating with the discharge tank 40 are formed within a frame of the liquid-proof wall 20 in the base plate 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fuel cell unit.

Background Art

[0002] In a fuel cell unit including a fuel cell stack, the fuel cell stack generates heat by a power generation reaction. In order to suppress a decrease in the power generation performance of the fuel cell stack, the fuel cell stack is cooled.

[0003] For example, the fuel cell system of Patent Document 1 includes a cooling system for cooling the stack inside a housing. The cooling system includes a cooling water container for storing cooling water, a pump for transporting the cooling water in the cooling water container to the stack, a radiator for radiating the cooling water, a cooling water supply pipe, and a cooling water discharge pipe. The cooling water before cooling the stack is supplied into the stack through the cooling water supply pipe by the operation of the pump. The cooling water that has cooled the stack is discharged from the stack through the cooling water discharge pipe.

[0004] A fuel cell system including a fuel cell stack is obliged to have a configuration for receiving cooling water. The fuel cell system of Patent Document 1 includes a first liquid receiving part and a second liquid receiving part for receiving cooling water. The first liquid receiving part is provided on the lower side of the stack inside the housing. The first liquid receiving part includes a discharge part for discharging the liquid accumulated in the first liquid receiving part to the outside of the first liquid receiving part. A pipe having a discharge path is connected to the discharge part. The second liquid receiving part is disposed below the first liquid receiving part. The second liquid receiving part is disposed at the lower part of the accommodation chamber of the housing. The pipe extends from the first liquid receiving part toward the second liquid receiving part.

[0005] Then, the cooling water leaked from the stack is received by the first liquid receiving part. The cooling water received by the first liquid receiving part is discharged from the discharge part to the second liquid receiving part through the pipe. The cooling water discharged from the first liquid receiving part is received by the second liquid receiving part. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-49200 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the fuel cell system described in Patent Document 1, cooling water leaking from the stack is discharged from the first liquid receiving section to the discharge section and then to the second liquid receiving section via piping. However, the cooling water discharged to the second liquid receiving section continues to accumulate in the second liquid receiving section. Furthermore, Patent Document 1 does not mention the leakage of cooling water from components other than the stack, nor does it mention the accumulation of leaked cooling water around components other than the stack. [Means for solving the problem]

[0008] A fuel cell unit to solve the above problems comprises a fuel cell stack, a radiator that exchanges heat between the coolant and the outside air, a forward path through which the coolant, whose heat has been exchanged in the radiator, flows toward the fuel cell stack, a return path through which the coolant, whose heat has been exchanged in the fuel cell stack, flows toward the radiator, and, if the direction in which the coolant flows in the forward and return paths is defined as the flow direction, a pump located downstream of the radiator and upstream of the fuel cell stack in the forward path in the flow direction, an intercooler located downstream of the pump and upstream of the fuel cell stack in the forward path in the flow direction, a connecting passage connecting a position downstream of the intercooler and upstream of the fuel cell stack in the forward path in the flow direction, and a position downstream of the fuel cell stack and upstream of the radiator in the return path in the flow direction, an ion exchanger provided in the connecting passage, and the radiator A fuel cell unit comprising a reserve tank for containing the coolant to be supplied, and an assembly member used to form a unit integrating the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank, wherein the assembly member comprises a base plate disposed below the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, the reserve tank, the forward passage, the return passage, and the connecting passage, a liquid containment wall projecting in a frame shape from the upper surface of the base plate, and a discharge tank disposed below the base plate, wherein, viewed from above, the forward passage, the return passage, the connecting passage, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank are arranged in a region enclosed by the liquid containment wall, and a drain port communicating with the discharge tank is formed within the frame of the liquid containment wall on the base plate.

[0009] According to this design, even if coolant leaks from one or more of the forward, return, connecting channels, radiator, pump, intercooler, ion exchanger, and reserve tank, the leaked coolant is contained within the enclosed area. The enclosed area is surrounded by a containment wall. Therefore, the containment wall prevents coolant from leaking outside the enclosed area. The coolant inside the containment wall can be discharged to the discharge tank through the drain port. Thus, coolant leaking from one or more of the forward, return, connecting channels, radiator, pump, intercooler, ion exchanger, and reserve tank is discharged from the enclosed area. This prevents coolant from accumulating in the enclosed area.

[0010] With respect to the fuel cell unit, the assembly member comprises a frame protruding from the base plate, the frame includes a plurality of columns protruding from the base plate, and when viewed from above, the columns may be bolted to the base plate outside the liquid-proof wall.

[0011] According to this design, no bolt penetration points are formed in the area that receives the coolant. Therefore, it is possible to prevent the coolant received in the frame area from leaking out from the points where the columns are fixed to the base plate.

[0012] With respect to the fuel cell unit, the drain port may be positioned along the inner surface of the liquid-proof wall when viewed from above. According to this, the discharge tank, which is connected to the drain port, can be positioned close to the liquid containment wall along the drain port.

[0013] The fuel cell unit is equipped with a blower that creates an airflow toward the radiator, and the radiator and the blower are positioned near one end along the upper surface of the base plate, and the drain port may be positioned near the one end.

[0014] According to this design, the air blower forms an airflow directed towards the radiator. To keep the air that has passed through the radiator away from the fuel cell unit, the radiator and air blower are positioned near one end of the base plate. When pumping coolant, shorter lengths for the forward and return paths are preferable to reduce pressure loss. As a result, the radiator, pump, forward path, and return path are positioned near one end of the base plate. The drain port is also located near this one end of the base plate. Therefore, even if coolant leaks from the radiator, pump, forward path, or return path, the coolant can be quickly discharged through the drain port. [Effects of the Invention]

[0015] According to the present invention, it is possible to suppress the accumulation of coolant in the area within the frame. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic perspective view showing the fuel cell unit of the embodiment. [Figure 2] This is a plan view of the base plate as seen from above. [Figure 3] This is a side view of the fuel cell unit as seen from the short side. [Figure 4] This is a plan view of the fuel cell unit as seen from above. [Figure 5] This is a block diagram schematically showing the cooling system. [Modes for carrying out the invention]

[0017] Below, one embodiment of the fuel cell unit will be described with reference to Figures 1 to 5. <Overall configuration of the fuel cell unit> As shown in FIG. 1, the fuel cell unit 10 includes an assembly member 11, a blower unit 29, a fuel cell stack 30, a radiator 31, a pump 32, an intercooler 33, an ion exchanger 34, a reserve tank 35, a discharge tank 40, a forward path 51, a return path 52, a connecting flow path 53, and a supply pipe 61. The fuel cell unit 10 is a stationary type used as an emergency power source.

[0018] <Assembly member> The assembly member 11 is used to integrate the fuel cell stack 30, the blower unit 29, the radiator 31, the pump 32, the intercooler 33, the ion exchanger 34, and the reserve tank 35 into a unit.

[0019] The assembly member 11 includes a base plate 12, a frame 13, and a liquid-proof wall 20. <Base plate> The base plate 12 is made of a rectangular metal plate. The base plate 12 has an upper surface 12a on one side in the plate thickness direction and a lower surface 12b on the other side in the plate thickness direction. The direction in which the long side of the base plate 12 extends is defined as the long side direction X. The direction in which the short side of the base plate 12 extends is defined as the short side direction Y. The long side direction X is one direction along the upper surface 12a, and the short side direction Y is the other direction along the upper surface 12a. The plate thickness direction of the base plate 12 is the vertical direction Z.

[0020] <Frame> As shown in Figures 2 and 3, the frame 13 protrudes upward from the base plate 12. The frame 13 comprises a first column 14a, a second column 14b, a third column 14c, a fourth column 14d, a first beam member 15a, a second beam member 15b, and a bracket 16. Thus, the frame 13 includes multiple columns. The first to fourth columns 14a to 14d protrude upward from the upper surface 12a of the base plate 12. Each of the first to fourth columns 14a to 14d is fixed to the upper surface 12a of the base plate 12. Each of the first to fourth columns 14a to 14d has a fixing piece 17 at its lower end. A fixing bolt 18 is inserted through each fixing piece 17. The fixing bolt 18 penetrates the base plate 12 in the thickness direction. The fixing bolt 18 is screwed into a nut 19 below the base plate 12. Therefore, each of the first to fourth columns 14a to 14d is fixed to the base plate 12 by fixing bolts 18 and nuts 19.

[0021] The first column 14a and the second column 14b are opposite each other in the short-side direction Y. The third column 14c and the fourth column 14d are opposite each other in the short-side direction Y. The first beam member 15a is stretched across the upper ends of the first column 14a and the second column 14b. The second beam member 15b is stretched across the upper ends of the third column 14c and the fourth column 14d. The bracket 16 is stretched across the first column 14a and the second column 14b below the first beam member 15a.

[0022] <Liquidproof wall> The liquid containment wall 20 protrudes in a frame shape from the upper surface 12a of the base plate 12. The liquid containment wall 20 is a rectangular frame. The longitudinal side of the liquid containment wall 20 extends in the longitudinal direction X. The liquid containment wall 20 comprises a first wall 20a, a second wall 20b, a third wall 20c, and a fourth wall 20d. Each of the first to fourth walls 20a to 20d is in the shape of an elongated plate. The first wall 20a and the second wall 20b are opposite each other in the longitudinal direction Y. Also, the first wall 20a and the second wall 20b are parallel to each other. The third wall 20c and the fourth wall 20d are opposite each other in the longitudinal direction X. Also, the third wall 20c and the fourth wall 20d are parallel to each other. For each of the third wall 20c and the fourth wall 20d, both ends in the short-side direction Y protrude more than the outer surface of the first wall 20a and the outer surface of the second wall 20b.

[0023] The liquid containment wall 20 is separated from the edge of the base plate 12. The area of ​​the upper surface 12a of the base plate 12 enclosed by the edge of the base plate 12 and the outer edge of the liquid containment wall 20 is defined as the outer frame region R1. The outer frame region R1 is rectangular in shape. The outer frame region R1 has a width in the long side direction X. The width of the outer frame region R1 in the long side direction X may be the same or different in the portion adjacent to the third wall 20c and the portion adjacent to the fourth wall 20d. The outer frame region R1 has a width in the short side direction Y. The width of the outer frame region R1 in the short side direction Y may be the same or different in the portion adjacent to the first wall 20a and the portion adjacent to the second wall 20b.

[0024] The first to fourth columns 14a to 14d are fixed to the outer region R1. The first column 14a is located outside the first wall 20a in the short-side direction Y. The second column 14b is located outside the second wall 20b in the short-side direction Y. The third column 14c and the fourth column 14d are located outside the third wall 20c in the long-side direction X. Therefore, the first to fourth columns 14a to 14d are bolted to the base plate 12 outside the liquid containment wall 20.

[0025] When viewed from above, the base plate 12 has brackets 16 that extend in the long-side direction X from the first column 14a and the second column 14b towards the fourth wall 20d. The area of ​​the upper surface 12a of the base plate 12 that is inside the inner edge of the liquid containment wall 20 is defined as the enclosed area R2. The enclosed area R2 is the area enclosed by the inner surface of the liquid containment wall 20. The enclosed area R2 is a rectangle with its long side extending in the long side direction X. When viewing the base plate 12 from above, a portion of the bracket 16 overlaps the enclosed area R2 in the vertical direction Z.

[0026] <First drain port and second drain port> The base plate 12 has a first drain port 12c and a second drain port 12d formed therein. Each of the first drain port 12c and the second drain port 12d is circular in shape. Each of the first drain port 12c and the second drain port 12d penetrates the base plate 12 in the thickness direction. The first drain port 12c and the second drain port 12d are formed within the frame of the liquid containment wall 20 on the base plate 12. When the base plate 12 is viewed from above, each of the first drain port 12c and the second drain port 12d is positioned along the inner surface of the first wall 20a. Specifically, a point on the circumference of the first drain port 12c and the second drain port 12d is slightly away from the inner surface of the first wall 20a along the short side direction Y. The first drain port 12c and the second drain port 12d are separated on both sides along the long side direction X. The first drain port 12c is located closer to the third wall 20c than the second drain port 12d, and the second drain port 12d is located closer to the fourth wall 20d than the first drain port 12c.

[0027] <Fuel cell stack> The fuel cell stack 30 is constructed by stacking multiple battery cells (not shown). The fuel cell stack 30 is, for example, a polymer electrolyte fuel cell. The fuel cell stack 30 has an anode (not shown), a cathode (not shown), and an electrolyte membrane (not shown). The fuel cell stack 30 generates electricity by chemically reacting hydrogen, which is supplied to the anode as a fuel gas, with oxygen, which is supplied to the cathode as an oxidizing gas. The fuel cell stack 30 is assembled to the frame 13.

[0028] As shown in Figure 4, the fuel cell stack 30 is located inside the frame 13. The fuel cell stack 30 is positioned above the upper surface 12a of the base plate 12.

[0029] <Radiator> The radiator 31 is attached to the bracket 16. As described above, when viewing the base plate 12 from above, a portion of the bracket 16 is positioned to overlap with the frame region R2 in the vertical direction Z. Therefore, the radiator 31, which is attached to a portion of the bracket 16, is positioned to overlap with the frame region R2 in the vertical direction Z. The radiator 31 exchanges heat between the coolant and the outside air.

[0030] <Air blower> As shown in Figure 1, the air blower 29 is adjacent to the radiator 31 in the long-side direction X. The air blower 29 has a case 29a and a fan 29b. The fan 29b is located in the center of the case 29a. The fan 29b rotates to form an airflow toward the radiator 31. The air flows from the first end to the second end in the long-side direction X, as shown by arrow N in Figures 1 and 4. To form such an airflow, the air blower 29 is positioned near the second end in the long-side direction X along the upper surface 12a of the base plate 12. Therefore, the air blower 29 and the radiator 31 are positioned near the end in one direction along the upper surface 12a of the base plate 12.

[0031] <Cooling device> The fuel cell unit 10 is equipped with a cooling device 28 for cooling the fuel cell stack 30 with coolant. The cooling device 28 includes a radiator 31, a pump 32, an intercooler 33, an ion exchanger 34, a reserve tank 35, a forward path 51, a return path 52, a connecting passage 53, and a supply pipe 61.

[0032] <Outbound and return journeys> As shown in Figure 5, the fuel cell stack 30 and the radiator 31 are connected by a forward path 51 and a return path 52. The forward path 51 connects the radiator 31 and the fuel cell stack 30. The forward path 51 is a flow path through which the coolant, which has been heat-exchanged in the radiator 31, flows toward the fuel cell stack 30. Therefore, the coolant flowing through the forward path 51 is the coolant that has been cooled in the radiator 31 through heat exchange with the outside air.

[0033] The return path 52 connects the fuel cell stack 30 and the radiator 31. The return path 52 is a flow path through which the coolant, which has been heat-exchanged in the fuel cell stack 30, flows towards the radiator 31. The coolant flowing through the return path 52 is the coolant that has been heated by heat exchange with the heat-generating fuel cell stack 30. The direction in which the coolant flows from the radiator 31, through the fuel cell stack 30, and back to the radiator 31 is defined as the "coolant flow direction." This flow direction is the direction in which the coolant flows in both the forward path 51 and the return path 52.

[0034] <pump> Pump 32 is located in the forward path 51. Pump 32 is located downstream of the radiator 31 in the flow direction and upstream of the fuel cell stack 30 in the forward path 51. Pump 32 pumps coolant under pressure to circulate coolant in the forward path 51 and the return path 52.

[0035] <Intercooler> The intercooler 33 is located in the forward flow path 51. The intercooler 33 is located downstream of the pump 32 in the flow direction and upstream of the fuel cell stack 30 in the forward flow path 51. The intercooler 33 cools the coolant after heat exchange in the radiator 31. The coolant cooled by the intercooler 33 then flows into the fuel cell stack 30.

[0036] <Reserve Tank> The reserve tank 35 contains coolant to be supplied to the radiator 31. The reserve tank 35 and the radiator 31 are connected by a supply pipe 61.

[0037] <Ion exchanger> The ion exchanger 34 removes electric charge from the coolant flowing out of the radiator 31. The ion exchanger 34 is located in a connecting channel 53 that connects the forward path 51 and the return path 52. The connecting channel 53 connects a position in the forward path 51 that is downstream of the intercooler 33 in the flow direction and upstream of the fuel cell stack 30, and a position in the return path 52 that is downstream of the fuel cell stack 30 in the flow direction and upstream of the radiator 31.

[0038] <Operation of the cooling system> The coolant cooled by the radiator 31 is cooled by the intercooler 33 before flowing into the fuel cell stack 30. The fuel cell stack 30 is cooled by heat exchange between the fuel cell stack 30 and the coolant. The coolant heated by heat exchange with the fuel cell stack 30 flows into the radiator 31. In the radiator 31, the coolant is cooled along with the airflow from the fan 29b.

[0039] Furthermore, a portion of the coolant cooled by the intercooler 33 flows through the connecting channel 53. The charge in the coolant is removed by the ion exchanger 34. The coolant from which the charge has been removed flows into the return channel 52.

[0040] <Placement of cooling devices on the base plate> As shown in Figures 1, 3, and 4, the pump 32 is positioned above the upper surface 12a of the base plate 12. The pump 32 is positioned above the base plate 12, closer to the fourth wall 20d in the long side direction X and closer to the first wall 20a in the short side direction Y. In other words, the pump 32 is positioned near one end of the long side direction X along the upper surface 12a of the base plate 12. Therefore, the pump 32 is positioned close to the radiator 31 in the long side direction X.

[0041] The intercooler 33 is positioned above the upper surface 12a of the base plate 12. The intercooler 33 is also positioned below the fuel cell stack 30. Within the upper position of the base plate 12, the intercooler 33 is located in the center along the long side X and closer to the second wall 20b along the short side Y.

[0042] The ion exchanger 34 is positioned above the upper surface 12a of the base plate 12. Furthermore, the ion exchanger 34 is positioned above the pump 32. Within the upper position of the base plate 12, the ion exchanger 34 is located near the fourth wall 20d in the long-side direction X and near the first wall 20a in the short-side direction Y. In other words, the ion exchanger 34 is positioned near one end of the long-side direction X along the upper surface 12a of the base plate 12. Therefore, the ion exchanger 34 is positioned close to the radiator 31 in the long-side direction X.

[0043] The reserve tank 35 is positioned above the upper surface 12a of the base plate 12. The reserve tank 35 is positioned near the center in the long-side direction X and near the center in the short-side direction Y above the base plate 12. The reserve tank 35 is positioned closer to the first wall 20a in the short-side direction Y than the fuel cell stack 30.

[0044] Therefore, the base plate 12 is positioned below the fuel cell stack 30, radiator 31, pump 32, intercooler 33, ion exchanger 34, reserve tank 35, forward path 51, return path 52, connecting path 53, and supply piping 61.

[0045] The fuel cell stack 30, radiator 31, pump 32, intercooler 33, ion exchanger 34, and reserve tank 35 are integrated into a single unit by the assembly member 11. Therefore, the assembly member 11 is used to integrate the fuel cell stack 30, radiator 31, pump 32, intercooler 33, ion exchanger 34, and reserve tank 35 into a single unit. As long as the fuel cell stack 30, radiator 31, pump 32, intercooler 33, ion exchanger 34, and reserve tank 35 are integrated into a single unit, the method of assembling each component to the assembly member 11 is arbitrary.

[0046] As shown in Figure 4, when viewing the fuel cell unit 10 from above, the radiator 31, pump 32, intercooler 33, ion exchanger 34, reserve tank 35, forward path 51, return path 52, connecting channel 53, and supply piping 61 are located within the framed region R2. In other words, the cooling device 28 is located above the framed region R2.

[0047] As described above, the pump 32 and the ion exchanger 34 are positioned close to the radiator 31 in the long-side direction X. The blower 29 also forms an airflow toward the radiator 31. In order to keep the air that has passed through the radiator 31 away from the fuel cell stack 30, the radiator 31 and the blower 29 are positioned near one end of the base plate 12 in the long-side direction X.

[0048] Furthermore, when pumping coolant by pump 32, shorter lengths are preferable for the forward passage 51 and the return passage 52 in order to reduce pressure loss. As a result, the radiator 31, pump 32, forward passage 51, and return passage 52 are positioned closer to one end of the long side X of the base plate 12.

[0049] Furthermore, the second drain port 12d is located near one end of the base plate 12. In other words, the second drain port 12d is located below or near the radiator 31, pump 32, supply path 51, and return path 52. Therefore, the connection point between the radiator 31 and the supply path 51, and the connection point between the pump 32 and the supply path 51 are located near the second drain port 12d. In addition, the connection point between the ion exchanger 34 and the connecting channel 53 is located near the second drain port 12d.

[0050] No components of the fuel cell unit 10 are located above the first drain port 12c. Furthermore, the connection points between the reserve tank 35 and the supply piping 61 are located at positions away from the first drain port 12c in both the long-side X and short-side Y directions.

[0051] <Discharge Tank> As shown in Figures 1 and 2, the discharge tank 40 is located below the base plate 12. The discharge tank 40 is a rectangular parallelepiped that is elongated in the long side direction X. The discharge tank 40 is equipped with a first inlet 41 and a second inlet 42. Each of the first inlet 41 and the second inlet 42 is circular in shape. The diameter of the first inlet 41 is the same as the diameter of the first drain port 12c. The diameter of the first inlet 41 may be larger or smaller than the diameter of the first drain port 12c. The diameter of the second inlet 42 is the same as the diameter of the second drain port 12d. The diameter of the second inlet 42 may be larger or smaller than the diameter of the second drain port 12d.

[0052] All or part of the first inlet 41 overlaps with the first drain port 12c in the vertical Z direction. Also, all or part of the second inlet 42 overlaps with the second drain port 12d in the vertical Z direction. Therefore, each of the first drain port 12c and the second drain port 12d is in communication with the discharge tank 40. Although not shown, a sealing member is provided between the base plate 12 and the discharge tank 40 to prevent leakage of coolant from the first inlet 41 and the first drain port 12c. Similarly, although not shown, a sealing member is provided between the base plate 12 and the discharge tank 40 to prevent leakage of coolant from the second inlet 42 and the second drain port 12d.

[0053] <Height of the containment wall and area of ​​the framed region> As shown in Figure 2, let [L1] be the dimension of the enclosed region R2 in the long side direction X. Dimension L1 is the length of the straight line connecting the inner surfaces of the third wall 20c and the fourth wall 20d in the long side direction X. Let [L2] be the dimension of the enclosed region R2 in the short side direction Y. Dimension L2 is the length of the straight line connecting the inner surfaces of the first wall 20a and the second wall 20b in the short side direction Y. The product of dimensions L1 and L2 is the area of ​​the enclosed region R2.

[0054] As shown in Figure 3, the dimension of the liquid containment wall 20 in the vertical Z direction is denoted as L3. Dimension L3 is the length of the liquid containment wall 20 from the upper surface 12a of the base plate 12 to the upper end of the liquid containment wall 20. The product of the area of ​​the frame region R2 and the dimension L3 is the volume of the region enclosed by the liquid containment wall 20.

[0055] The volume is determined by the volume of the coolant. The coolant is constant because it circulates through the cooling device 28. The volume is set to be a predetermined multiple of the volume of the coolant. The dimensions L3 of the liquid containment wall 20 and the area of ​​the inner frame region R2 are adjusted to achieve this volume. The area of ​​the inner frame region R2 is set to be large enough to accommodate the entire cooling device 28 within the inner frame region R2. Dimension L3 is set according to this area of ​​the inner frame region R2.

[0056] <Operation of the Embodiment> Even if coolant leaks from the cooling device 28 or any of the connection points, the coolant will accumulate inside the containment wall 20. The coolant inside the containment wall 20 will flow along the upper surface 12a of the frame region R2 and be discharged downwards to the base plate 12 through the first drain port 12c and the second drain port 12d. The coolant discharged from the first drain port 12c is discharged to the discharge tank 40 through the first inlet 41. The coolant discharged from the second drain port 12d is discharged to the discharge tank 40 through the second inlet 42.

[0057] <Effects of the Embodiment> According to the above embodiment, the following effects can be obtained. (1) The cooling device 28 is placed in the enclosed area R2. Therefore, even if coolant leaks from the cooling device 28, the leaked coolant is contained in the enclosed area R2. The enclosed area R2 is surrounded by a liquid containment wall 20. Therefore, the liquid containment wall 20 prevents the coolant from leaking outside the enclosed area R2. The coolant in the enclosed area R2 is then discharged to the discharge tank 40 through the first drain port 12c and the second drain port 12d. In other words, the coolant leaked from the cooling device 28 is discharged from the enclosed area R2. Therefore, it is possible to prevent coolant from accumulating in the enclosed area R2.

[0058] (2) The coolant in the framed region R2 is discharged to the discharge tank 40 through the first drain port 12c and the second drain port 12d. This prevents the components of the cooling device 28 from being submerged in the coolant.

[0059] (3) The volume of the space enclosed by the liquid containment wall 20 and the base plate 12 is set to exceed the volume of the coolant. Therefore, even if a coolant leak occurs and all of the coolant is discharged inside the liquid containment wall 20, all of the coolant can be stored inside the liquid containment wall 20. As a result, leakage of the coolant outside the liquid containment wall 20 can be suppressed.

[0060] (4) Of the frame 13 of the assembly member 11, the first to fourth columns 14a to 14d are fixed to the base plate 12 by fixing bolts 18. The first to fourth columns 14a to 14d are bolted to the outer region R1 of the base plate 12. Therefore, there are no bolt fastening points in the inner region R2. Thus, it is possible to prevent coolant from leaking out to the bottom of the base plate 12 through the bolt fastening points.

[0061] (5) The first drain port 12c and the second drain port 12d are each positioned in the frame region R2 along the inner surface of the first wall 20a. Therefore, the discharge tank 40, which communicates with the first drain port 12c and the second drain port 12d, can also be positioned below the base plate 12, close to the first wall 20a. Thus, space can be secured below the base plate 12 in areas other than the discharge tank 40. As a result, the space can be effectively utilized to arrange the components of the fuel cell unit 10.

[0062] (6) The radiator 31 and the air blower 29 are located near one end of the base plate 12 in the long side direction X. The radiator 31, pump 32, supply line 51, and return line 52 are located near this one end of the base plate 12. The second drain port 12d is located near this one end of the base plate 12. Therefore, even if coolant leaks from the radiator 31, pump 32, supply line 51, and return line 52, the coolant can be quickly discharged from the second drain port 12d.

[0063] (7) The liquid containment wall 20 is formed by elongated plate-shaped first to fourth walls 20a to 20d. These first to fourth walls 20a to 20d can reinforce the base plate 12 as ribs. Therefore, the liquid containment wall 20 can be provided on the base plate 12 while the base plate 12 is reinforced.

[0064] (8) The base plate 12 is provided with a first drain port 12c and a second drain port 12d. For example, compared to the case where there is only one drain port, the number of places from which the coolant can be discharged to the discharge tank 40 can be increased. As a result, the accumulation of coolant in the frame region R2 can be further suppressed.

[0065] (9) For each of the third wall 20c and the fourth wall 20d, both ends in the short-side direction Y protrude more than the outer surface of the first wall 20a and the outer surface of the second wall 20b. Therefore, when the third wall 20c and the fourth wall 20d are used as ribs to reinforce the base plate 12, the area that can be reinforced can be expanded.

[0066] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. ○The first drain port 12c and the second drain port 12d do not have to be round holes, there may be only one, and they may be located at any position within the frame region R2.

[0067] ○ The upper surface 12a of the base plate 12 may have a slope that slopes downward toward the first drain port 12c or the second drain port 12d. ○The fuel cell unit 10 does not necessarily have to be equipped with a blower unit 29. In this case, the coolant is cooled solely by heat exchange in the radiator 31.

[0068] ○If the cooling device 28 is located within the framed region R2, the positions of the radiator 31, pump 32, intercooler 33, ion exchanger 34, and reserve tank 35 may be changed as appropriate.

[0069] ○The first to fourth columns 14a to 14d of the frame 13 may protrude from the inner frame region R2 of the upper surface 12a of the base plate 12. In this case, it is preferable that the first to fourth columns 14a to 14d are not fixed by fixing bolts 18. For example, the first to fourth columns 14a to 14d are welded to the upper surface 12a.

[0070] ○If the cooling device 28 can be placed in the area R2 within the frame, the liquid containment wall 20 does not have to be a rectangular frame. The frame shape of the liquid containment wall 20 may be changed as appropriate to suit the placement of the cooling device 28, such as an elliptical frame or a trapezoidal frame.

[0071] ○The fuel cell unit 10 may be mounted on an industrial vehicle as a power source for the industrial vehicle. ○The radiator 31 may be positioned closer to one end of the base plate 12 in the short side direction Y.

[0072] ○The reserve tank 35 may be connected to the radiator 31 without the supply piping 61. ○The connection points of the forward path 51 and the return path 52 to the fuel cell stack 30 may be changed as appropriate.

[0073] Next, the technical concepts that can be understood from the above embodiments and alternative examples are described below. [Aspect 1] A fuel cell stack, a radiator that exchanges heat between a coolant and the outside air, a forward path through which the coolant, whose heat has been exchanged in the radiator, flows toward the fuel cell stack, a return path through which the coolant, whose heat has been exchanged in the fuel cell stack, flows toward the radiator, and, if the direction in which the coolant flows in the forward and return paths is defined as the flow direction, a pump provided downstream of the radiator and upstream of the fuel cell stack in the forward path in the flow direction, an intercooler provided downstream of the pump and upstream of the fuel cell stack in the forward path in the flow direction, a connecting passage connecting a position downstream of the intercooler and upstream of the fuel cell stack in the forward path in the flow direction, and a position downstream of the fuel cell stack and upstream of the radiator in the return path in the flow direction, an ion exchanger provided in the connecting passage, and a container for the coolant supplied to the radiator. A fuel cell unit comprising a reserve tank and an assembly member used to form a unit integrating the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank, wherein the assembly member comprises a base plate disposed below the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, the reserve tank, the forward path, the return path, and the connecting path, a liquid containment wall projecting in a frame shape from the upper surface of the base plate, and a discharge tank disposed below the base plate, wherein, when viewed from above, the forward path, the return path, the connecting path, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank are arranged in a region enclosed by the liquid containment wall, and a drain port communicating with the discharge tank is formed within the frame of the liquid containment wall on the base plate.

[0074] [Aspect 2] The fuel cell unit according to [Aspect 1], wherein the assembly member comprises a frame protruding from the base plate, the frame includes a plurality of columns protruding from the base plate, and when viewed from above, the columns are bolted to the base plate outside the liquid containment wall.

[0075] [Aspect 3] The fuel cell unit according to [Aspect 1] or [Aspect 2], wherein, when viewed from above, the drain port is positioned along the inner surface of the liquid-proof wall. [Aspect 4] A fuel cell unit according to any one of [Aspect 1] to [Aspect 3], comprising a blower that creates an airflow toward the radiator, wherein the radiator and the blower are positioned near the end in one direction along the upper surface of the base plate, and the drain port is positioned near the end in the one direction. [Explanation of symbols]

[0076] R2...Framed area, 10...Fuel cell unit, 11...Assembly component, 12...Base plate, 12a...Top surface, 12c...First drain port, 12d...Second drain port, 13...Frame, 14a~14d...First column~Fourth column, 20...Liquid containment wall, 29...Air blower, 30...Fuel cell stack, 31...Radiator, 32...Pump, 33...Intercooler, 34...Ion exchanger, 35...Reserve tank, 40...Discharge tank, 51...Forward path, 52...Return path, 53...Connecting path.

Claims

1. Fuel cell stack and A radiator exchanges heat between the coolant and the outside air, The coolant, whose heat has been exchanged in the radiator, flows in the forward path toward the fuel cell stack, The return path through which the coolant, which has undergone heat exchange in the fuel cell stack, flows toward the radiator, If the direction in which the coolant flows in the forward and return paths is defined as the flow direction, then in the forward path, a pump is provided downstream of the radiator in the flow direction and upstream of the fuel cell stack, In the forward path, an intercooler is provided downstream of the pump in the flow direction and upstream of the fuel cell stack, A connecting channel is provided that connects a position downstream of the intercooler in the flow direction and upstream of the fuel cell stack in the forward path, and a position downstream of the fuel cell stack in the flow direction and upstream of the radiator in the return path. An ion exchanger provided in the aforementioned connecting channel, A reserve tank containing the coolant supplied to the radiator, A fuel cell unit comprising: an assembly member used to form a unit integrating the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank, The assembly member comprises a base plate positioned below the fuel cell stack, the radiator, the pump, the intercooler, the ion exchanger, the reserve tank, the forward path, the return path, and the connecting flow path, A liquid-proof wall protruding in a frame shape from the upper surface of the base plate, The base plate is located below the discharge tank, Viewed from above, the forward path, the return path, the connecting channel, the radiator, the pump, the intercooler, the ion exchanger, and the reserve tank are arranged within a framed area enclosed by the liquid-proof wall. A fuel cell unit characterized in that a drain port communicating with the discharge tank is formed within the frame of the liquid-proof wall in the base plate.

2. The assembly member comprises a frame that protrudes from the base plate, The frame includes a plurality of columns protruding from the base plate, The fuel cell unit according to claim 1, wherein, when viewed from above, the column is bolted to the base plate outside the liquid-proof wall.

3. The fuel cell unit according to claim 1 or claim 2, wherein, when viewed from above, the drain port is positioned along the inner surface of the liquid-proof wall.

4. A fuel cell unit according to claim 1 or claim 2, comprising a blower that creates an airflow toward the radiator, wherein the radiator and the blower are positioned near one end along the upper surface of the base plate, and the drain port is positioned near the one end.

Images