Fuel cell unit

Abstract

To provide a fuel cell unit which can air-cool air-cooled components while water-cooling a fuel cell stack without increasing the size.SOLUTION: A fuel cell stack 22 can be water-cooled by heat exchange with a coolant flowing through a coolant pipe and an electrically-driven air compressor 23, a DC / DC converter 81, and an inverter device 82 can be air-cooled by air generated by a first fan 27. The first fan 27 is installed side by side with the electrically-driven air compressor 23, the DC / DC converter 81, and the inverter device 82 in a direction in which the air generated by the first fan 27 flows and located at the opposite side of a suction port 62a across an internal space S of a housing 40. The electrically-driven air compressor 23, the DC / DC converter 81, and the inverter device 82 are disposed at different positions in a height direction of the housing 40 relative to the fuel cell stack 22.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, the fuel cell system disclosed in Patent Document 1 has a fuel cell stack housed in a housing. Because the fuel cell stack generates heat when generating electricity, a radiator is installed in the housing to water-cool the fuel cell stack, and a fan is also installed to improve the cooling efficiency of the coolant in the radiator.

[0003] Furthermore, the fuel cell system disclosed in Patent Document 1 has a DC / DC converter that transforms the output power of the fuel cell stack. The DC / DC converter generates heat when converting the output power of the fuel cell stack. In the fuel cell system of Patent Document 1, the DC / DC converter is air-cooled by air sent toward a radiator by driving a fan. It is well known that fuel cell systems are equipped with air-cooled parts that require air cooling in addition to the DC / DC converter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-102097 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the fuel cell system of Patent Document 1 uses a radiator and a fan for water-cooling the fuel cell stack, and also uses a fan for air-cooling the DC / DC converter, which results in a large fuel cell system. For this reason, there is a demand for a fuel cell unit that can water-cool the fuel cell stack and air-cool parts such as the DC / DC converter without increasing the size. [Means for solving the problem]

[0006] A fuel cell unit for solving the above problems comprises a fuel cell stack, an electric air compressor that supplies oxygen to the cathode of the fuel cell stack, a DC / DC converter that transforms the output power of the fuel cell stack, an inverter device that drives the electric air compressor, a housing that houses the fuel cell stack, the electric air compressor, the DC / DC converter, and the inverter device, an air intake port provided in the housing to communicate the internal space of the housing with the outside, and a fan that is installed on the opposite side of the internal space in the housing from the air intake port and that generates a flow of air in the internal space through the air intake port. The gist of the present invention is a fuel cell unit having the above structure, wherein the fuel cell stack can be water-cooled by heat exchange with cooling water flowing through a cooling water pipe, and the electric air compressor, the DC / DC converter, and the inverter device can be air-cooled by air flowing through the internal space, the electric air compressor, the DC / DC converter, and the inverter device are installed in the housing alongside the fan in the air flow direction, and the fuel cell stack is arranged at a different position in the height direction of the housing relative to the fan, the electric air compressor, the DC / DC converter, and the inverter device.

[0007] According to this configuration, the fuel cell stack is water-cooled by heat exchange with the coolant. The electric air compressor, DC / DC converter, and inverter are arranged alongside the fan in the airflow direction. Therefore, the airflow generated in the interior space of the housing by the fan's operation effectively air-cools the electric air compressor, DC / DC converter, and inverter. The water-cooled fuel cell stack, the electric air compressor, DC / DC converter, and inverter are arranged separately in the vertical direction. Compared to a configuration in which the fuel cell stack, the electric air compressor, DC / DC converter, and inverter are randomly arranged in the vertical direction, the electric air compressor, DC / DC converter, and inverter can be effectively air-cooled while the fuel cell stack is also effectively water-cooled. Even if the fuel cell unit does not have a radiator required for water-cooling the fuel cell stack, the electric air compressor, DC / DC converter, and inverter can all be effectively air-cooled while the fuel cell stack is effectively water-cooled. As a result, the fuel cell unit can water-cool the fuel cell stack while air-cooling the electric air compressor, DC / DC converter, and inverter device, without increasing the size of the fuel cell unit.

[0008] In the fuel cell unit, the electric air compressor, the DC / DC converter, and the inverter device may be arranged below the fuel cell stack in the height direction, and the fan and the air intake may be arranged below the fuel cell stack in the height direction.

[0009] This allows heat generated by the electric air compressor, DC / DC converter, and inverter device to rise. Therefore, compared to when the electric air compressor, DC / DC converter, and inverter device are located in the upper part of the internal space, heat is less likely to build up in these devices. Furthermore, in the lower part of the housing, the fan is driven to generate airflow from the intake port toward the fan. This airflow can cool the electric air compressor, DC / DC converter, and inverter device. Therefore, the electric air compressor, DC / DC converter, and inverter device can be air-cooled efficiently.

[0010] The fuel cell unit may include a rack portion having legs erected on the upper surface of the bottom plate of the housing and long plate-shaped support portions supported by the legs, the fuel cell stack being supported above the bottom plate in the height direction by the support portions, the fuel cell unit having a water pump below the fuel cell stack in the height direction that sends the cooling water to the cooling water piping, and the electric air compressor being positioned below the long plate-shaped support portions in the height direction and not covered from above by the support portions.

[0011] With this, the rack section allows the fuel cell stack to be positioned higher in the height direction than the bottom plate. The water pump then allows cooling water to be sent from below the fuel cell stack toward the fuel cell stack. This prevents the cooling water from stagnating in the cooling water piping. Furthermore, the electric air compressor is not covered from above by the support section. Therefore, the support section does not prevent the rise of heat generated by the electric air compressor. This prevents heat from building up in the electric air compressor. Therefore, the fuel cell stack can be effectively water-cooled while the electric air compressor can be effectively air-cooled.

[0012] In a fuel cell unit, if the fan is a first fan, the unit may further include a second fan that generates an air flow toward the fuel cell stack, and the second fan may be positioned alongside the fuel cell stack in the direction of the air flow generated by the second fan, and may be installed on the opposite side of the internal space from the air intake port in the housing.

[0013] This allows the fuel cell stack to be air-cooled by the air flow generated by the second fan. Therefore, the fuel cell stack can be air-cooled and water-cooled, allowing the fuel cell stack to be cooled appropriately. Furthermore, the air flow generated by the second fan allows hydrogen that has leaked into the housing and accumulated at the top of the housing to be expelled to the outside of the housing via the second fan. [Effects of the Invention]

[0014] The present invention can water-cool the fuel cell stack and air-cool the air-cooled components without increasing the size. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view showing a fuel cell unit and a storage section according to the embodiment. [Figure 2] FIG. 2 is a perspective view showing the fuel cell unit of the embodiment from the air intake port side. [Figure 3] FIG. 2 is a diagram schematically illustrating a fuel cell unit. [Figure 4] FIG. 2 is a perspective view schematically showing a fuel cell unit. [Figure 5] FIG. 2 is a cross-sectional view showing the fuel cell unit from the electric air compressor side. [Figure 6] FIG. 2 is a cross-sectional view showing the fuel cell unit from the DC / DC converter side. [Figure 7] FIG. 4 is a schematic diagram showing the flow of air inside the housing. [Figure 8] FIG. 10 is a cross-sectional view showing another example of a fuel cell unit. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the fuel cell unit will now be described with reference to Figures 1 to 7. The fuel cell unit is housed in a housing section. <Storage section> 1, the storage unit 10 has a storage body 12 that defines a storage space 11 that is open to the front, and a mounting member 13 on which a fuel cell unit 20 to be stored in the storage space 11 is placed. The storage body 12 has support rails 12a that support the mounting member 13. The mounting member 13, supported by the support rails 12a, can be moved in and out of the storage space 11 by means of the support rails 12a.

[0017] <Fuel cell unit> 3, the fuel cell unit 20 has a housing 40 and a fuel cell module 21 housed in an internal space S of the housing 40. A hydrogen tank 14, an air filter 15, and a radiator 16 are provided outside the housing 40, and the hydrogen tank 14, the air filter 15, and the radiator 16 can be connected to the fuel cell unit 20.

[0018] <Fuel cell module> The fuel cell module 21 includes a fuel cell stack 22, an electric air compressor 23, a diluter 24, a water pump 25, a hydrogen pump 26, a first fan 27, and a second fan 28. The fuel cell module 21 also includes a hydrogen supply pipe 31 connected to the anode (not shown) of the fuel cell stack 22, a cooling water pipe 32 for carrying cooling water circulating between the fuel cell stack 22 and the radiator 16, and an air intake pipe 33 connected to the electric air compressor 23. Although cooling water is used as the cooling water, other types of liquids may also be used. The fuel cell module 21 also includes a cathode offgas pipe 34a connecting the cathode of the fuel cell stack 22 to the diluter 24, and an anode offgas pipe 34b connecting the anode of the fuel cell stack 22 to the diluter 24. The fuel cell module 21 also has an exhaust pipe 35 connected to the diluter 24, an air supply pipe 36 connected to the cathode of the fuel cell stack 22, and a hydrogen circulation pipe 37 connecting the anode of the fuel cell stack 22 and the hydrogen supply pipe 31.

[0019] The hydrogen supply pipe 31 passes through the internal space S from the fuel cell stack 22 and is drawn out to the outside of the casing 40, and is connected to a hydrogen connection pipe 18 connected to the hydrogen tank 14 outside the casing 40. The cooling water pipe 32 includes an outward pipe 32a that sends cooling water to the fuel cell stack 22 and a return pipe 32b that sends cooling water from the fuel cell stack 22. The outward pipe 32a passes through the internal space S from the fuel cell stack 22 and is drawn out to the outside of the casing 40, and is connected to a first connection pipe 17a connected to the radiator 16 outside the casing 40. Similarly, the return pipe 32b passes through the internal space S from the fuel cell stack 22 and is drawn out to the outside of the casing 40, and is connected to a second connection pipe 17b connected to the radiator 16 outside the casing 40. A water pump 25 is provided on the return pipe 32b, and the water pump 25 is housed in the internal space S. The air intake pipe 33 is drawn from the electric air compressor 23 through the internal space S to the outside of the housing 40, and is connected to the air filter 15 outside the housing 40.

[0020] The cathode off-gas piping 34a, the anode off-gas piping 34b, the exhaust piping 35, the air supply piping 36, and the hydrogen circulation piping 37 are housed in the internal space S. A hydrogen pump 26 is provided on the hydrogen circulation piping 37, and the hydrogen pump 26 is housed in the internal space S.

[0021] <Fuel cell unit operation> In the fuel cell unit 20, hydrogen is supplied to the anode of the fuel cell stack 22 from the hydrogen tank 14 via the hydrogen connection pipe 18 and the hydrogen supply pipe 31. In addition, air compressed by the electric air compressor 23 is supplied to the cathode of the fuel cell stack 22 via the air supply pipe 36. The electric air compressor 23 draws in air that has passed through the air filter 15 via the air intake pipe 33. The fuel cell stack 22 generates direct current electrical energy by reacting hydrogen with oxygen in the air. The fuel cell stack 22 generates water as it generates electricity.

[0022] Anode off-gas, which is exhaust containing surplus hydrogen discharged from the fuel cell stack 22, contains produced water. The anode off-gas from which the produced water has been separated flows into the hydrogen circulation pipe 37 and is returned to the hydrogen supply pipe 31 by the hydrogen pump 26. A portion of the anode off-gas separated from the anode off-gas is discharged to the diluter 24 via the anode off-gas pipe 34b. Cathode off-gas, which is exhaust containing water generated in conjunction with the power generation of the fuel cell stack 22, is discharged to the diluter 24 via the cathode off-gas pipe 34a.

[0023] In the diluter 24, the produced water is separated from the cathode off-gas and the anode off-gas. The hydrogen contained in the anode off-gas is diluted with the cathode off-gas from the fuel cell stack 22, and then discharged to the outside of the housing 40 via the discharge pipe 35.

[0024] In the cooling water pipe 32, the cooling water is circulated between the fuel cell stack 22 and the radiator 16 by the water pump 25 pumping the cooling water. The cooling water circulating through the cooling water pipe 32 flows into the heat exchange passage in the fuel cell stack 22 through the first connecting pipe 17a and the outward pipe 32a, absorbing heat generated in the fuel cell stack 22 and cooling the fuel cell stack 22. Therefore, the fuel cell stack 22 can be water-cooled by the cooling water. The cooling water that flows into the heat exchange passage of the radiator 16 through the return pipe 32b and the second connecting pipe 17b is cooled by the radiator 16.

[0025] As shown in Figures 4 to 7, the fuel cell module 21 has a DC / DC converter 81 that transforms the output power of the fuel cell stack 22, an inverter device 82 that drives the electric air compressor 23, a reactor 83, and a control unit 84 that controls the fuel cell module 21.

[0026] The DC / DC converter 81 is electrically connected to the fuel cell stack 22. A voltage transformed by the DC / DC converter 81 is applied to the control unit 84, the electric air compressor 23, the first fan 27, and the second fan 28. The drive of the electric air compressor 23, the water pump 25, and the hydrogen pump 26 is controlled by the inverter device 82.

[0027] <Case> 2 and 4, the housing 40 has a bottom plate 41, a top plate 60, a first attachment plate 61, a second attachment plate 62, and a pair of side plates 71. An internal space S of the housing 40 is defined by the bottom plate 41, the top plate 60, the first attachment plate 61, the second attachment plate 62, and the pair of side plates 71.

[0028] The bottom plate 41 is a rectangular plate. The direction in which the long edges of the bottom plate 41 extend is defined as a first direction X, and the direction in which the short edges of the bottom plate 41 extend is defined as a second direction Y. The first direction X and the second direction Y are perpendicular to each other on the top surface 41a of the bottom plate 41. The first attachment plate 61 and the second attachment plate 62 face each other in the first direction X, and the pair of side plates 71 face each other in the second direction Y.

[0029] The housing 40 includes a rack section 42 that stands on the upper surface 41a of the bottom plate 41. The rack section 42 has four legs 42a that stand on the upper surface 41a of the bottom plate 41, and long plate-shaped support sections 42b that are supported on the upper ends of the legs 42a.

[0030] The support portion 42b has a longitudinal direction extending in the first direction X and a lateral direction extending in the second direction Y. The dimension of the support portion 42b in the second direction Y is smaller than the dimension of the bottom plate 41 in the second direction Y. In addition, the dimension of the support portion 42b in the first direction X is smaller than the dimension of the bottom plate 41 in the first direction X.

[0031] The support portion 42b is disposed above the bottom plate 41 in the height direction by the legs 42a. The support portion 42b covers almost the entire upper surface 41a of the bottom plate 41 in the first direction X on one side in the second direction Y. In the internal space S of the housing 40, a rack space S1 is defined which is surrounded by the bottom plate 41, the four legs 42a, and the support portion 42b.

[0032] The area of ​​the upper surface 41a of the bottom plate 41 that is not covered from above by the support portion 42b is referred to as the uncovered area R1, and the area that is covered from above by the support portion 42b is referred to as the covered area R2. The covered area R2 is the area below the support portion 42b in the height direction.

[0033] As shown in FIGS. 1 and 3, a first fan 27 and a second fan 28 are attached to the first mounting plate 61. The first fan 27 and the second fan 28 are DC fans driven by direct current power. The first fan 27 is installed below the second fan 28 in the height direction. The height direction is a direction perpendicular to the upper surface 41a of the bottom plate 41. The height direction is also the vertical direction when the fuel cell unit 20 is placed on a horizontal surface.

[0034] 1, the outward piping 32a and the return piping 32b penetrate the first attachment plate 61 and protrude to the outside of the housing 40, and the hydrogen supply piping 31 and the air intake pipe 33 penetrate the first attachment plate 61 and protrude to the outside of the housing 40. Furthermore, the discharge piping 35 penetrates the first attachment plate 61 and protrudes to the outside of the housing 40.

[0035] 1 is connected to outward pipe 32a, which protrudes outside of housing 40, and second connection pipe 17b is connected to return pipe 32b. Hydrogen connection pipe 18, which is not shown in FIG. 1, is connected to hydrogen supply pipe 31, and air filter 15 is connected to air intake pipe 33. Discharge pipe 35 opens outside of housing 40. Therefore, first attachment plate 61 has first fan 27, second fan 28, hydrogen supply pipe 31, outward pipe 32a, return pipe 32b, air intake pipe 33, and discharge pipe 35 all arranged together.

[0036] 2 and 3, an air intake port 62a is formed in the second attachment plate 62. The air intake port 62a is provided in the housing 40 to connect the internal space S of the housing 40 with the outside. The first fan 27 and the second fan 28 are installed on the opposite side of the internal space S from the air intake port 62a in the housing 40. Specifically, the first fan 27 and the second fan 28 are arranged on the first attachment plate 61 located on one end of the housing 40 in the first direction X, and the air intake port 62a is arranged on the second attachment plate 62 located on the other end of the housing 40 in the first direction X. Each of the first fan 27 and the second fan 28 generates an air flow in the internal space S of the housing 40 through the air intake port 62a.

[0037] 1, the fuel cell unit 20 is placed on the mounting member 13 with the second attachment plate 62 positioned at the back of the storage section 10 and the first attachment plate 61 positioned on the opening side of the storage section 10. Therefore, when the fuel cell unit 20 is stored in the storage space 11, the second attachment plate 62 is located at the back of the storage space 11. Although not shown, inside the storage body 12, there is a gap between the second attachment plate 62 and the inner surface of the storage body 12 that faces it.

[0038] The front view of the fuel cell unit 20 refers to the view of the fuel cell unit 20 stored in the storage section 10 from the opening side of the storage space 11. When viewed from the front of the fuel cell unit 20, the first attachment plate 61 can be seen from the front. When viewed from the front, a pair of side plates 71 sandwiching the first attachment plate 61 form the side surfaces of the fuel cell unit 20. Therefore, the side of the fuel cell unit 20 is the side of the side plate 71.

[0039] <Placement on the chassis> 4 to 6, a DC / DC converter 81, an inverter device 82, a reactor 83, an electric air compressor 23, a diluter 24, and a water pump 25 are arranged on an upper surface 41a of the bottom plate 41. Of the internal space S, a space in which the DC / DC converter 81, the inverter device 82, the reactor 83, the electric air compressor 23, the diluter 24, and the water pump 25 are arranged is referred to as a first space 111. In the embodiment, the first space 111 is a space that is above the upper surface 41a of the bottom plate 41 and below the support portion 42b in the height direction. The first space 111 is the entire space on the upper surface 41a of the bottom plate 41 in the first direction X and the second direction Y.

[0040] The DC / DC converter 81 and the reactor 83 are disposed below the support portion 42b in the height direction. That is, the DC / DC converter 81 and the reactor 83 are disposed in the rack portion space S1 and the covered region R2. The DC / DC converter 81 and the reactor 83 are disposed in the first direction X such that the DC / DC converter 81 is closer to the second attachment plate 62 than the reactor 83.

[0041] The inverter device 82 is disposed on the bottom plate 41 so as to straddle both the uncovered area R1 and the covered area R2. A portion of the inverter device 82 is disposed in the rack space S1, and the inverter device 82 is disposed closer to the second attachment plate 62 than the DC / DC converter 81 and the reactor 83. The electric air compressor 23 is disposed in the uncovered area R1. Therefore, the electric air compressor 23 is disposed below the long plate-shaped support portion 42b in the height direction and at a position not covered from above by the support portion 42b.

[0042] The diluter 24 and the water pump 25 are disposed at a position sandwiched between the electric air compressor 23 and the DC / DC converter 81 in the second direction Y. The diluter 24 and the water pump 25 are disposed below the support portion 42b in the height direction. That is, the diluter 24 and the water pump 25 are disposed in the rack portion space S1 and the covered region R2. The diluter 24 and the water pump 25 may also be disposed in the uncovered region R1.

[0043] The fuel cell stack 22 and the hydrogen pump 26 are disposed on the upper surface of the support portion 42b. Of the internal space S, the space in which the fuel cell stack 22 and the hydrogen pump 26 are disposed is referred to as the second space 112. The second space 112 is a space that is above the upper surface of the support portion 42b and below the top plate 60 in the height direction. The second space 112 is the entire space in the first direction X and the second direction Y on the upper surface of the support portion 42b. The second space 112 is also a space that is above the first space 111 in the height direction.

[0044] The fuel cell stack 22 is supported above the bottom plate 41 in the height direction by support portions 42b of a rack portion 42 that is erected on the bottom plate 41 of the housing 40. Therefore, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82 are disposed below the fuel cell stack 22 in the height direction. The electric air compressor 23 is also disposed in an uncovered area R1 that is not covered by the rack portion 42.

[0045] The electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82, which are arranged on the upper surface 41a of the bottom plate 41, generate heat as they are driven, but the amount of heat generated is less than that of the fuel cell stack 22. For this reason, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82 are air-cooled components that can be cooled by air. In the following description, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82 may be referred to as air-cooled components in some cases.

[0046] 5 and 6, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82 are disposed at approximately the same height as the first fan 27. When the first fan 27 is driven, a first air flow F1 is formed in the internal space S of the housing 40, flowing from the air intake port 62a toward the first fan 27 along the upper surface 41a of the bottom plate 41. Therefore, the first fan 27 is disposed alongside the inverter device 82, electric air compressor 23, reactor 83, and DC / DC converter 81 in the direction of the air flow generated by driving the first fan 27.

[0047] The fuel cell stack 22 and the hydrogen pump 26 are disposed at approximately the same height as the second fan 28. When the second fan 28 is driven, a second air flow F2 is formed in the internal space S of the housing 40. The second air flow F2 flows from the air intake 62a toward the upper surface of the support portion 42b, and then flows along the upper surface of the support portion 42b toward the second fan 28. Therefore, the second fan 28 is disposed alongside the fuel cell stack 22 in the direction of the air flow generated by driving the second fan 28.

[0048] 7, the first air flow F1 and the second air flow F2 generated by driving the first fan 27 and the second fan 28 flow while spreading over the entire second direction Y inside the housing 40. That is, the first air flow F1 flows over the entire first direction X and the entire second direction Y in the first space 111. The second air flow F2 flows over the entire first direction X and the entire second direction Y in the second space 112. Therefore, the electric air compressor 23, the reactor 83, the DC / DC converter 81, and the inverter device 82, which are arranged on the upper surface 41a of the bottom plate 41, are air-cooled by heat exchange with the air. The fuel cell stack 22 and the hydrogen pump 26, which are arranged on the upper surface of the support portion 42b, are also air-cooled by heat exchange with the air.

[0049] In the fuel cell unit 20, the air-cooled components, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82, are disposed at different positions in the height direction of the casing 40 relative to the water-cooled fuel cell stack 22. Specifically, in the fuel cell unit 20, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82 are disposed below the water-cooled fuel cell stack 22 in the height direction of the casing 40.

[0050] [Operation of the embodiment] In the fuel cell unit 20 housed in the housing 10, the control unit 84 causes the inverter device 82 to drive the electric air compressor 23 and the hydrogen pump 26 in order to generate electricity using the fuel cell stack 22. As a result, the inverter device 82 and the electric air compressor 23 generate heat. In addition, the power generated by the fuel cell stack 22 is transformed by the DC / DC converter 81. As a result, the DC / DC converter 81 generates heat, and the reactor 83 also generates heat. As electricity is generated, the fuel cell stack 22 generates heat.

[0051] The water pump 25 is driven to circulate the cooling water through the cooling water pipe 32. The cooling water cooled by the radiator 16 water-cools the fuel cell stack 22. The control unit 84 also drives the first fan 27 and the second fan 28.

[0052] By driving the first fan 27, a first air flow F1 is formed in the internal space S of the housing 40, flowing from the air intake port 62a toward the first fan 27. The air flows above the bottom plate 41 toward the first fan 27 while spreading throughout the entire second direction Y inside the housing 40. Therefore, the electric air compressor 23, DC / DC converter 81, reactor 83, and inverter device 82, which are arranged in the first space 111, are air-cooled by heat exchange with the air. Furthermore, by driving the second fan 28, a second air flow F2 is formed in the internal space S of the housing 40, flowing from the air intake port 62a toward the second fan 28. The air flows above the support portion 42b toward the second fan 28 while spreading throughout the entire second direction Y. Therefore, the fuel cell stack 22 arranged in the second space 112 is air-cooled by heat exchange with the air. Therefore, the fuel cell stack 22 is water-cooled and air-cooled.

[0053] [Effects of the embodiment] According to the above embodiment, the following effects can be obtained. (1) The fuel cell stack 22 is water-cooled by heat exchange with the coolant. The radiator 16 is installed outside the housing 40 and is not installed within the housing 40. The electric air compressor 23, DC / DC converter 81, and inverter device 82 are arranged alongside the first fan 27 in the flow direction of the first air flow F1. This allows the electric air compressor 23, DC / DC converter 81, and inverter device 82 to be suitably air-cooled. The water-cooled fuel cell stack 22 and the air-cooled electric air compressor 23, DC / DC converter 81, and inverter device 82 are arranged separately in the vertical direction. For example, compared to a case in which the fuel cell stack 22, electric air compressor 23, DC / DC converter 81, and inverter device 82 are arranged randomly in the vertical direction, the electric air compressor 23, DC / DC converter 81, and inverter device 82 can be suitably air-cooled while the fuel cell stack 22 can also be suitably water-cooled. As a result, the fuel cell unit 20 can water-cool the fuel cell stack 22 while air-cooling the electric air compressor 23, DC / DC converter 81, and inverter device 82 without becoming larger than when a radiator 16 is installed.

[0054] (2) For example, a comparative example will be described in which the electric air compressor 23, the DC / DC converter 81, and the inverter device 82 are air-cooled using only the air sent by the first fan 27, while also cooling the cooling water circulating through the cooling water pipe 32. In the comparative example, the air sent from the first fan 27 is dispersed, reducing the air-cooling efficiency.

[0055] However, in the fuel cell unit 20, components that can be air-cooled, such as the electric air compressor 23, DC / DC converter 81, and inverter device 82, are positioned optimally in the first space 111, and the first fan 27 and the air intake 62a are arranged side by side so that they can be cooled by the air sent by the first fan 27. Therefore, the first air flow F1 generated by driving the first fan 27 is directed toward the electric air compressor 23, DC / DC converter 81, and inverter device 82, and therefore the electric air compressor 23, DC / DC converter 81, and inverter device 82 can be air-cooled in an appropriate manner.

[0056] (3) The second fan 28 is disposed in a position aligned with the fuel cell stack 22 in the direction of the air flow generated by the second fan 28. Therefore, the fuel cell stack 22 can also be air-cooled by the second air flow F2 generated by driving the second fan 28. Therefore, the fuel cell stack 22 can be air-cooled and water-cooled, and therefore the fuel cell stack 22 can be cooled appropriately.

[0057] (4) The second air flow F2 generated by driving the second fan 28 allows hydrogen that has leaked inside the housing 40 and accumulated at the top of the housing 40 to be discharged to the outside of the housing 40 through the second fan 28.

[0058] (5) Air-cooled components such as the electric air compressor 23, DC / DC converter 81, and inverter device 82 are disposed below the fuel cell stack 22 in the height direction. The first fan 27 and the air intake 62a are disposed below the fuel cell stack 22 in the height direction, and the air intake 62a and the first fan 27 are disposed with the air-cooled components sandwiched between them. This makes it less likely for heat to build up in the air-cooled components than when the air-cooled components are disposed in the upper part of the housing 40. In addition, a first air flow F1 is generated in the lower part of the housing 40 by driving the first fan 27. This first air flow F1 allows the air-cooled components to be cooled efficiently.

[0059] (6) The fuel cell stack 22 is supported by the long plate-shaped support portion 42b at a height higher than the bottom plate 41. The water pump 25 is disposed below the fuel cell stack 22 in the height direction. The water pump 25 can send the cooling water from below the fuel cell stack 22 to above it. This prevents the cooling water from accumulating in the cooling water pipe 32.

[0060] Furthermore, even though the support portions 42b that support the fuel cell stack 22 cover the bottom plate 41 from above, the electric air compressor 23 is not covered from above by the long plate-shaped support portions 42b. Therefore, the rise of heat generated by the electric air compressor 23 is not prevented by the support portions 42b. This makes it possible to prevent heat from being trapped in the electric air compressor 23.

[0061] (7) The fuel cell stack 22 is primarily cooled by water cooling using cooling water. This allows for more appropriate temperature management of the fuel cell stack 22 than when the fuel cell stack 22 is air-cooled using only air blown from the first fan 27 and the second fan 28, for example.

[0062] (8) The first fan 27 and the second fan 28 are driven by the application of a voltage transformed by the DC / DC converter 81. Therefore, the first fan 27 and the second fan 28 can be made smaller than, for example, a fan that is driven at low voltage. This increases the degree of freedom in installing the first fan 27 and the second fan 28 in the housing 40. Furthermore, the first fan 27 and the second fan 28 do not require the airflow volume required to cool the fuel cell stack 22, so noise associated with driving the first fan 27 and the second fan 28 can be reduced.

[0063] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0064] The electric air compressor 23 may be covered from above by the support portion 42b. 8, the fuel cell stack 22 may be disposed on the upper surface 41a of the bottom plate 41, below the support portions 42b of the rack portion 42 in the height direction. In this case, the DC / DC converter 81, the electric air compressor 23, the reactor 83, and the inverter device 82 are disposed on the upper surface of the support portions 42b. The first fan 27 is disposed in the upper part of the housing 40, alongside the electric air compressor 23, the DC / DC converter 81, the reactor 83, and the inverter device 82, in the direction of the flow of air generated by the first fan 27.

[0065] Therefore, in the internal space S, the first space 111 in which the DC / DC converter 81, the inverter device 82, the reactor 83, and the electric air compressor 23 are arranged is provided above the support part 42b in the height direction. In addition, the second space 112 in which the fuel cell stack 22 and the hydrogen pump 26 are arranged is provided above the bottom plate 41 and below the support part 42b in the height direction.

[0066] The second fan 28 may be omitted. The fuel cell stack 22 and the electric air compressor 23 may be attached to the housing 40 by brackets or the like and disposed in the internal space S without using the rack portion 42 . [Explanation of symbols]

[0067] S...internal space, 20...fuel cell unit, 22...fuel cell stack, 23...electric air compressor, 25...water pump, 27...first fan, 28...second fan, 32...cooling water piping, 40...housing, 41...bottom plate, 41a...top surface, 42...rack portion, 42a...legs, 42b...support portion, 62a...air intake, 81...DC / DC converter, 82...inverter device.

Claims

1. a fuel cell stack; an electric air compressor that supplies oxygen to the cathode of the fuel cell stack; a DC / DC converter that transforms the output power of the fuel cell stack; an inverter device that drives the electric air compressor; a housing that houses the fuel cell stack, the electric air compressor, the DC / DC converter, and the inverter device; an air intake provided in the housing to communicate an internal space of the housing with the outside; a fan that is installed on the opposite side of the housing from the intake port across the internal space, and that generates an air flow in the internal space through the intake port, The fuel cell stack can be water-cooled by heat exchange with cooling water flowing through a cooling water pipe, the electric air compressor, the DC / DC converter, and the inverter device can be air-cooled by air flowing through the internal space; The electric air compressor, the DC / DC converter, and the inverter device are installed in the housing alongside the fan in the air flow direction, The fuel cell stack comprises: The fuel cell unit is arranged at a different position in the height direction of the housing from the fan, the electric air compressor, the DC / DC converter, and the inverter device.

2. 2. The fuel cell unit according to claim 1, wherein the electric air compressor, the DC / DC converter, and the inverter device are arranged below the fuel cell stack in the height direction, and the fan and the air intake are arranged below the fuel cell stack in the height direction.

3. a rack portion having legs erected on an upper surface of the bottom plate of the housing and a long plate-shaped support portion supported by the legs; the fuel cell stack is supported by the support portion above the bottom plate in the height direction, the fuel cell unit has a water pump below the fuel cell stack in the height direction, the water pump sending the cooling water to the cooling water pipe; 3. The fuel cell unit according to claim 2, wherein the electric air compressor is disposed below the long plate-shaped support portion in the height direction and at a position not covered from above by the support portion.

4. If the fan is a first fan, a second fan that generates an air flow toward the fuel cell stack; A fuel cell unit as described in claim 2 or claim 3, wherein the second fan is positioned next to the fuel cell stack in the direction of the flow of air generated by the second fan, and is installed on the opposite side of the housing from the air intake port across the internal space.

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