Fuel cell system

Abstract

To reduce variation in power generation amount for each power generation module.SOLUTION: A fuel cell system includes a fuel cell module, a hydrogen supply system, and a circulation system. The fuel cell module includes a fuel cell stack, a combustion unit, and a module case for accommodating them. The hydrogen supply system includes a hydrogen supply line connected to a hydrogen inlet of the fuel cell module, and a hydrogen blower provided in the hydrogen supply line. The circulation system includes a heat exchanger, a combustion gas line connected to a combustion gas inlet of the fuel cell module, and a reflux line connected to the hydrogen supply line, and distributes hydrogen off-gas having passed through the heat exchanger from the fuel cell module to the combustion gas line and the reflux line. A plurality of fuel cell modules, hydrogen supply systems, and circulation systems are provided in one-to-one correspondence, and the lengths of the reflux lines are the same, and the lengths of the hydrogen supply lines on the downstream side of the hydrogen blower are the same.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] This specification discloses a fuel cell system.

Background Art

[0002] Conventionally, as this type of fuel cell system, there has been proposed one including a cell stack, a high-temperature housing that houses the cell stack and a combustor, a fuel gas supply passage that supplies fuel gas to the cell stack by the operation of a fuel gas pump, a fuel off-gas supply passage that guides fuel off-gas from the cell stack to the outside of the high-temperature housing and then re-introduces it into the high-temperature housing and supplies it to the combustor, a second heat exchanger disposed at an intermediate portion (outside the high-temperature housing) of the fuel off-gas supply passage, and a recycle passage that branches from the downstream side of the second heat exchanger of the fuel off-gas supply passage and is connected between a fuel gas pump and a second throttle member in the fuel gas supply passage (see, for example, Patent Document 1). In this fuel cell system, fuel off-gas from the cell stack is cooled by the second heat exchanger and then fed to the combustor, and a part of the fuel off-gas fed from the second heat exchanger to the combustor is returned to the fuel gas supply passage through the recycle passage by the negative pressure generated by the operation of the fuel gas pump.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When configuring a unit including a plurality of power generation modules including the above-described cell stack, combustor, fuel off-gas supply passage, second heat exchanger, recycle passage, etc., or configuring a system including a plurality of such units, there is a possibility that the power generation amount varies from module to module or from unit to unit.

[0005] When the fuel cell system of the present disclosure includes a plurality of power generation modules, its main object is to provide a fuel cell system capable of suppressing variations in the power generation amount for each module.

Means for Solving the Problems

[0006] The fuel cell system of the present disclosure has adopted the following means to achieve the above main object.

[0007] The fuel cell system of the present disclosure includes a fuel cell stack that generates power by a fuel gas supplied to the anode and an oxidant gas supplied to the cathode, a combustion unit that burns a combustible gas introduced from a combustion gas inlet, and a heat-insulating module case that houses the fuel cell stack and the combustion unit, a hydrogen supply system including a hydrogen inlet of the fuel cell module connected to the inlet of the anode and a hydrogen supply line connected to a hydrogen supply source, and a hydrogen blower provided in the hydrogen supply line, a hydrogen off-gas line connected to a hydrogen off-gas outlet of the fuel cell module connected to the outlet of the anode, a heat exchanger provided in the hydrogen off-gas line, a combustion gas line connected to the combustion gas inlet of the fuel cell module, and a reflux line connected to the hydrogen supply line, and includes a circulation system that distributes the hydrogen off-gas discharged from the outlet of the anode and passing through the heat exchanger to the combustion gas line and the reflux line, the hydrogen supply system includes a governor provided upstream of the hydrogen blower in the hydrogen supply line, the reflux line branches from the hydrogen off-gas line and is connected between the hydrogen blower and the governor in the hydrogen supply line, a plurality of the fuel cell modules are provided, a plurality of the hydrogen supply systems and the circulation systems are provided so as to correspond one-to-one to the fuel cell modules respectively, the lengths of the reflux lines of the plurality of circulation systems are the same respectively, The gist is that the lengths on the downstream side of the hydrogen blowers in the respective hydrogen supply lines of the plurality of hydrogen supply systems are the same for each.

[0008] In the fuel cell system of the present disclosure, in a fuel cell system including a plurality of fuel cell modules and provided with a plurality of hydrogen supply systems (including hydrogen supply lines and hydrogen blowers) and circulation systems (including reflux lines) corresponding one-to-one to the fuel cell modules, the lengths of the respective reflux lines of the plurality of circulation systems are the same, and the lengths on the downstream side of the hydrogen blowers in the respective hydrogen supply lines of the plurality of hydrogen supply systems are the same. Thereby, the pressure and flow rate of the gas flowing through the hydrogen supply line for each fuel cell module can be made the same. As a result, variations in the power generation amount for each fuel cell module can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Embodiments for carrying out the present disclosure will be described with reference to the drawings.

[0011] FIG. 1 is an external perspective view of the fuel cell system 10, FIG. 2 is an internal perspective view of the fuel cell unit 20 included in the fuel cell system 10, FIG. 3 is an internal side view of the fuel cell unit 20, FIG. 4 is an internal perspective view of the fuel cell unit 20 excluding the frame 21, FIG. 5 is an internal top view of the fuel cell unit 20 excluding the frame 21, FIG. 6 is an internal side view of the fuel cell unit 20 excluding the frame 21, and FIG. 7 is a schematic configuration diagram of the fuel cell system 10.

[0012] As shown in FIG. 1, the fuel cell system 10 of the present embodiment includes a plurality (N) of fuel cell units 20 each including a plurality (M) of fuel cell modules 30. The plurality of fuel cell units 20 are arranged side by side on the left and right, and the fuel cell system 10 is configured by connecting the fuel cell modules 30 in series between the plurality of fuel cell units 20.

[0013] Each fuel cell unit 20 is a unit having a substantially rectangular parallelepiped appearance, and includes a frame 21 that supports and fixes various components of the fuel cell unit 20.

[0014] The frame 21 is configured by connecting a plurality of columns arranged on the outer periphery with beams. In the present embodiment, the columns of the frame 21 include two long front corner columns 22a and two long rear corner columns 22b arranged at the four corners, and two long side columns 22c provided between one front corner column 22a and rear corner column 22b and between the other front corner column 22a and rear corner column 22b. In addition, two short auxiliary columns 22d are provided between the two side columns 22c and the two rear corner columns 22b.

[0015] The beams of the frame 21 include a bottom beam 23a that connects the front corner column 22a, the rear corner column 22b, and the side column 22c at the bottom, and a ceiling beam 23b that connects the front corner column 22a and the side column 22c at the ceiling. Further, the beams of the frame 21 include a plurality of upper and lower module fixing beams 23c that connect the rear corner column 22b and the side column 22c above the bottom beam 23a, a plurality of upper and lower hydrogen blower sub-assembly fixing beams 23d that connect the front corner column 22a and the side column 22c between the bottom beam 23a and the ceiling beam 23b, and an air blower sub-assembly fixing beam 23e that connects the side column 22c and the auxiliary column 22d between the bottom beam 23a and the lower module fixing beam 23c.

[0016] Each fuel cell unit 20 includes a fuel cell module 30 that includes one fuel cell stack 31, a hydrogen supply system 40, an air supply system 50, a circulation system 60, a waste heat recovery system 70, and an electronic control unit (ECU) 80. In this embodiment, each fuel cell unit 20 includes a plurality (M) of fuel cell modules 30 (fuel cell stacks 31) connected in series. Further, the hydrogen supply system 40, the air supply system 50, the circulation system 60, and the electronic control unit 80 are provided one by one for one fuel cell module 30.

[0017] The plurality of fuel cell modules 30 of the fuel cell unit 20 are fixed to the plurality of upper and lower module fixing beams 23c by bolts. Each fuel cell module 30 all has, as shown in FIG. 7, in addition to the fuel cell stack 31, a combustor 32, a heat exchanger, and the like. These are housed in a module case 35 having heat insulation properties. The fuel cell stack 31 has a plurality of solid oxide type single cells each including an electrolyte, an anode (fuel electrode) disposed on one surface side of the electrolyte, and a cathode (air electrode) disposed on the other surface side of the electrolyte. The fuel cell stack 31 generates electricity by an electrochemical reaction between hydrogen supplied from a hydrogen supply source 1 (for example, a hydrogen tank) and oxygen contained in air.

[0018] The plurality of hydrogen supply systems 40 of the fuel cell unit 20 are fixed to the frame 21 so as to face the corresponding fuel cell modules 30 in the front-rear direction. As shown in FIGS. 2 to 7, each hydrogen supply system 40 branches from the other end of a common fuel pipe 25 having one end connected to a hydrogen supply source 1 and is connected to a hydrogen inlet 41i of the corresponding fuel cell module 30 that leads to the anode inlet of the fuel cell stack 31 through an anode gas pipe 41. The anode gas pipe 41 has a hydrogen blower 43 provided therein. An on-off valve 26 (a two-way valve) is provided in the fuel pipe 25. By operating the hydrogen blower 43, the hydrogen gas from the hydrogen supply source 1 is supplied from the fuel pipe 25 through the anode gas pipe 41 to the corresponding fuel cell module 30 (the anode of the fuel cell stack 31). Since the hydrogen blower 43 is installed in each of the anode gas pipes 41 (branch pipes), the supply amount of hydrogen gas can be controlled for each fuel cell module 30 by individually controlling each hydrogen blower 43.

[0019] A governor 44 is provided on the upstream side of the hydrogen blower 43 in the anode gas pipe 41, and a flow rate sensor 45 is provided on the upstream side of the governor 44 in the anode gas pipe 41. The hydrogen blower 43, the governor 44, and the flow rate sensor 45 are sub-assembled as a hydrogen blower sub-assembly, and the hydrogen blower sub-assembly is bolted to a hydrogen blower sub-assembly fixing beam 23d via a bracket.

[0020] The plurality of air supply systems 50 of the fuel cell unit 20 are collectively arranged in the empty space at the bottom of the frame 21 (below the two fuel cell modules 30). As shown in FIGS. 2 to 7, each air supply system 50 includes a cathode gas pipe 51 having one end connected to an air inlet 51i of the fuel cell module 30 that is connected to the cathode inlet of the fuel cell stack 31, an air blower 53 provided in the cathode gas pipe 51, and an air filter 54 provided at the other end of the cathode gas pipe 51. By operating the air blower 53, air is sucked from the air filter 54 into the cathode gas pipe 51, and the sucked air is supplied through the cathode gas pipe 51 to the fuel cell module 30 (the cathode of the fuel cell stack 31). Since the air blowers 53 are respectively installed in each cathode gas pipe 51, the supply amount of air can be controlled for each fuel cell module 30 by individually controlling each air blower 53.

[0021] A flow rate sensor 55 is provided on the downstream side of the air blower 53 in the cathode gas pipe 51. The air blower 53, the air filter 54, and the flow rate sensor 55 are sub-assembled as an air blower sub-assembly, and the air blower sub-assembly is fixed to the bottom beam 23a or the air blower sub-assembly fixing beam 23e by bolts via a bracket.

[0022] The plurality of circulation systems 60 of the fuel cell unit 20 include, as shown in FIGS. 2 to 7, an anode off-gas pipe 61 having one end connected to an anode off-gas outlet 61o of the fuel cell module 30 that is connected to the anode outlet of the fuel cell stack 31, a condenser 62 provided in the anode off-gas pipe 61, and a combustion gas pipe 65 connected to a combustion gas inlet 65i of the fuel cell module 30 that branches at a first branch point J1 on the downstream side of the condenser 62 in the anode off-gas pipe 61 and is connected to the combustor 32. The condenser 62 extends in the vertical direction and is arranged between the fuel cell module 30 and the hydrogen supply system 40 (hydrogen blower sub-assembly) facing each other.

[0023] The anode off-gas discharged from the anode outlet of the fuel cell stack 31 into the anode off-gas pipe 61 is condensed of the water vapor contained in the anode off-gas by heat exchange with a heat exchange medium (cooling water) in the condenser 62, and then supplied as combustion gas to the combustor 32 through the combustion gas pipe 65. Then, the anode off-gas (combustion gas) is mixed and burned with the cathode off-gas directly introduced from the cathode outlet of the fuel cell stack 31 in the combustor 32. The heat recovered by heat exchange with the heat exchange medium in the condenser 62 is supplied to heat utilization equipment installed in a factory or the like.

[0024] Also, the plurality of circulation systems 60 of the fuel cell unit 20 include a condensed water tank 66 disposed at the bottom of the frame 21 of the fuel cell unit 20, and a condensed water pipe 68 branched at a second branch point J2 on the downstream side of the condenser 62 and upstream of the first branch point J1 in the anode off-gas pipe 61 and connected to the condensed water tank 66. The condensed water generated by being condensed by the condenser 62 flows into the condensed water pipe 68 at the second branch point J2 and is stored in the condensed water tank 66 through the condensed water pipe 68. In the present embodiment, the anode off-gas inlet 62i into which the anode off-gas of the condenser 62 is introduced is located below the anode off-gas outlet 61o of the fuel cell module 30, the second branch point J2 is located below the anode off-gas outlet 62o from which the anode off-gas of the condenser 62 is discharged, and the condensed water tank 66 is located below the second branch point J2. And the condensed water pipe 68 extends downward from the second branch point J2 and is connected to the condensed water tank 66. Thereby, the condensed water generated in the condenser 62 can be drained smoothly. A drain valve 67 is provided at the bottom of the condensed water tank 66, and the condensed water in the condensed water tank 66 is drained through the drain valve 67. The condensed water tank 66 and the drain valve 67 are sub-assembled as a condensed water tank sub-assembly, and the condensed water tank sub-assembly is fixed to the bottom beam 23a of the frame 21 by bolts via a bracket.

[0025] Furthermore, the plurality of circulation systems 60 of the fuel cell unit 20 also include a reflux gas pipe 63 that branches at a first branch point J1, which is the other end of the anode off-gas pipe 61, and is connected between a hydrogen blower 43 and a governor 44 in the anode gas pipe 41 of the corresponding hydrogen supply system 40. An orifice 64 for regulating the flow rate of the anode off-gas (reflux gas) flowing through the reflux gas pipe 63 is formed in the reflux gas pipe 63. Since the anode off-gas pipe 61 branches into the reflux gas pipe 63 and the combustion gas pipe 65 at the first branch point J1, by presetting the opening pressure of the governor 44 and the opening ratio of the orifice 64, the anode off-gas can be refluxed to the anode gas pipe 41 at a desired reflux ratio as the reflux gas. Also, in the present embodiment, the first branch point J1 is located above the second branch point J2, and the hydrogen supply system 40 (hydrogen blower sub-assembly) and the combustion gas inlet 65i of the fuel cell module 30 are located above the first branch point J1. For this reason, after the anode off-gas is gas-liquid separated by the condenser 62, the liquid component (condensed water) is led downward from the second branch point J2, while the gas component is led upward from the first branch point J1 and supplied to the anode gas pipe 41 and the combustor 32. Thereby, the gas-liquid separation of the anode off-gas can be performed more reliably, and the water vapor partial pressure in the pipes can be reduced. As a result, the anode off-gas can be smoothly refluxed to the anode gas pipe 41 as the reflux gas, or the anode off-gas can be smoothly supplied to the combustor 32 as the combustion gas, and the efficiency of the fuel cell system 10 can be further improved.

[0026] As shown in FIG. 7, the exhaust heat recovery system 70 includes a plurality of combustion exhaust gas pipes 72 having one end connected to the combustor 32 of each fuel cell module 30, a collecting pipe 73 connected to the other ends of the plurality of combustion exhaust gas pipes 72, and a heat exchanger 71 provided in the collecting pipe 73. The combustion exhaust gas discharged from the combustor 32 of each fuel cell module 30 into the combustion exhaust gas pipe 72 gathers in the collecting pipe 73, exchanges heat with the heat exchange medium in the heat exchanger 71, and then is discharged to the outside air. The heat recovered by the heat exchange with the heat exchange medium is supplied to heat utilization equipment installed in a factory or the like.

[0027] The plurality of electronic control units 80 of each fuel cell unit 20 are for controlling the operation of the corresponding fuel cell module 30, and are provided for each fuel cell module 30. Each electronic control unit 80 is configured as a microprocessor centered on a CPU, and in addition to the CPU, has a ROM, a RAM, input / output ports, etc. Detection signals from the flow rate sensor 45 of the corresponding hydrogen supply system 40, the flow rate sensor 55 of the corresponding air supply system 50, etc. are input to the electronic control unit 80 via the input port. On the other hand, control signals from the electronic control unit 80 to the hydrogen blower 43 of the corresponding hydrogen supply system 40, the air blower 53 of the corresponding air supply system 50, the drain valve 67 of the corresponding circulation system 60, etc. are output via the output port. As shown in FIGS. 2 and 3, the plurality of electronic control units 80 are fixed to the auxiliary column 22d by bolts via brackets.

[0028] In this embodiment, the fuel cell unit 20 has a plurality (M) of fuel cell stacks 31 connected in series, and the fuel cell system 10 has a plurality (N) of fuel cell units 20 connected such that the fuel cell stacks 31 are connected in series between the plurality of fuel cell units 20. Thereby, in the fuel cell system 10, N×M fuel cell stacks 31 are connected in series to obtain a large power generation output. Therefore, in the fuel cell system 10, by simply changing the number of fuel cell units 20 to be connected, it is possible to meet various power generation output requirements. Further, each fuel cell unit 20 includes a plurality of sets of fuel cell modules 30 (fuel cell stacks 31) of the same configuration, hydrogen supply systems 40 (hydrogen blower sub-assemblies), air supply systems 50 (air blower sub-assemblies), and circulation systems 60 (condensers 62 and condensate tank sub-assemblies). Thereby, the individual sizes of the constituent members (auxiliary machines) can be reduced, and it becomes possible to accommodate them in the limited space of the fuel cell unit 20. As a result of these, while corresponding to a large power generation output, the fuel cell system 10 can be made smaller. Furthermore, it is possible to significantly reduce the cost due to the mass production effect.

[0029] Also, as described above, since the plurality of hydrogen supply systems 40 (hydrogen blower sub-assemblies 42) housed in one fuel cell unit 20 are arranged to face the corresponding fuel cell modules 30 back to back, the pipe lengths of the anode gas pipe 41, the anode off-gas pipe 61, and the reflux gas pipe 63 can be made the same. As a result, the pressure and flow rate of the gas flowing through the fuel supply lines (the anode gas pipe 41, the anode off-gas pipe 61, and the reflux gas pipe 63) can be made the same. Consequently, variations in the power generation amount for each fuel cell module 30 or each fuel cell unit 20 can be suppressed. Also, the specifications of each component member of the hydrogen supply system 40 can be made the same, and costs can be reduced. Furthermore, in each electronic control unit 80, individual control logic and parameter adjustment for each fuel cell module 30 are unnecessary, and control becomes easier. In addition, since the plurality of air supply systems 50 are collectively arranged in the empty space at the bottom of the frame 21, the dead space can be reduced and the fuel cell unit 20 can be made smaller.

[0030] Also, since hydrogen gas is used as the fuel gas, there is no need to supply a reformer for reforming (steam reforming) the raw fuel gas (natural gas or LP gas) and water (steam) to the fuel cell module 30. For this reason, there is no water vapor partial pressure in the anode gas pipe 41, and hydrogen gas can be supplied at a relatively low supply pressure. Also, in the present embodiment, the anode off-gas from the anode outlet is passed through a condenser 62 outside the fuel cell module 30 to remove at least a part of the water vapor contained in the anode off-gas and then refluxed to the hydrogen supply system 40 (anode gas pipe 41), so that the efficiency of the fuel cell stack 31 can be improved. Also, since the remaining anode off-gas with at least a part of the water vapor removed is supplied to the combustor 32, the combustibility of the anode off-gas in the combustor 32 can be further improved.

[0031] In the above-described embodiment, the orifice 64 is provided in the reflux gas pipe 63, but a solenoid valve may be provided.

[0032] In the above-described embodiment, the first branch point J1 is positioned above the second branch point J2. However, the first branch point J1 may be at the same position as the second branch point J2. For example, the first branch point J1 and the second branch point J2 may be configured to branch into three from the anode off-gas pipe 61.

[0033] In the above-described embodiment, the plurality of fuel cell modules 30 included in the fuel cell unit 20 are installed so as to be arranged in the vertical direction. However, they may be installed so as to be arranged in the horizontal direction.

[0034] In the above-described embodiment, the plurality of hydrogen supply systems 40 included in the fuel cell unit 20 are arranged so as to face the corresponding fuel cell modules 30. However, the plurality of hydrogen supply systems 40 may be arranged at positions paired with the corresponding fuel cell modules 30. For example, they may be above the fuel cell modules 30 or below the fuel cell modules 30. However, it is desirable that the plurality of hydrogen supply systems 40 be arranged in the vicinity of the corresponding fuel cell modules 30.

[0035] In the above-described embodiment, the air supply system 50 (air blower sub-assembly) is arranged in the empty space at the bottom of the frame 21. However, the air supply system 50 may be arranged at any location as long as it is an empty space within the frame 21. For example, the air supply system 50 may be arranged so as to face the fuel cell module 30 on the side opposite to the hydrogen supply system 40.

[0036] In the above-described embodiment, the fuel cell system 10 is configured by connecting a plurality of fuel cell units 20 having the same configuration. However, it may be configured by a single fuel cell unit 20.

[0037] In the above-described embodiment, the fuel cell system 10 includes a plurality of fuel cell units 20 such that the fuel cell stacks 31 are connected in series between the fuel cell units 20. However, it may be configured as a large-scale system in which a plurality of fuel cell systems 10 are further connected. That is, a plurality of fuel cell systems 10 may be connected such that the fuel cell stacks 31 connected in series between the fuel cell units 20 are further connected in series between the fuel cell systems 10. In this case, when the number of fuel cell stacks 31 included in one fuel cell unit 20 is M, the number of fuel cell units 20 included in one fuel cell system 10 is N, and the number of fuel cell systems 10 to be connected is L, M×N×L fuel cell stacks 31 are connected in series, and it is possible to meet a demand for a larger power generation output. Further, the plurality of fuel cell systems 10 included in the large-scale system may be connected in parallel. In this case, repairs and inspections can be performed for each fuel cell system 10 while the large-scale system is operating.

[0038] As described above, the embodiments for implementing the present disclosure have been described using the embodiments. However, the present disclosure is not limited to such embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure.

Industrial Applicability

[0039] The present disclosure can be used in the manufacturing industry of fuel cell systems and the like.

Explanation of Reference Numerals

[0040] 10 Fuel cell system, 30 Fuel cell module, 31 Fuel cell stack, 32 Combustor (combustion section), 35 Module case, 40 Hydrogen supply system, 41 Anode gas pipe (hydrogen supply line), 41i Hydrogen inlet, 43 Hydrogen blower, 44 Governor, 60 Circulation system, 61 Anode off-gas pipe (hydrogen off-gas line), 61o Anode off-gas outlet, 62 Condenser (heat exchanger), 62i Anode off-gas inlet (hydrogen off-gas inlet), 62o Anode off-gas outlet (hydrogen off-gas outlet), 63 Recirculation gas pipe (recirculation line), 64 Orifice, 65 Combustion gas pipe (combustion gas line), 65i Combustion gas inlet, J1 First branch point, J2 Second branch point.

Claims

1. A fuel cell module including: a fuel cell stack that generates electricity using a fuel gas supplied to an anode and an oxidant gas supplied to a cathode; a combustion unit that burns a combustible gas introduced from a combustion gas inlet; and a heat-insulating module case that houses the fuel cell stack and the combustion unit, a hydrogen supply system including: a hydrogen supply line connected to a hydrogen inlet of the fuel cell module that is connected to an anode inlet and a hydrogen supply source; and a hydrogen blower provided in the hydrogen supply line, a circulation system including: a hydrogen off-gas line connected to a hydrogen off-gas outlet of the fuel cell module that is connected to an anode outlet; a heat exchanger provided in the hydrogen off-gas line; a combustion gas line connected to the combustion gas inlet of the fuel cell module; and a reflux line connected to the hydrogen supply line, the circulation system having a function of distributing the hydrogen off-gas discharged from the anode outlet and passing through the heat exchanger to the combustion gas line and the reflux line, the hydrogen supply system including a governor provided upstream of the hydrogen blower in the hydrogen supply line, the reflux line branching from the hydrogen off-gas line and being connected between the hydrogen blower and the governor in the hydrogen supply line, wherein a plurality of the fuel cell modules are provided, wherein a plurality of the hydrogen supply systems and the circulation systems are provided so as to correspond one-to-one to each of the fuel cell modules, wherein lengths of the reflux lines of the plurality of circulation systems are the same, wherein lengths of the hydrogen supply lines of the plurality of hydrogen supply systems downstream of the hydrogen blower are the same, A fuel cell system.

2. The fuel cell system according to claim 1, wherein the hydrogen off-gas line branches into the reflux line and the combustion gas line at a first branch point downstream of the heat exchanger, wherein the circulation system includes an orifice provided in the reflux line, wherein the hydrogen off-gas that has passed through the heat exchanger is distributed to the reflux line and the combustion gas line at a predetermined distribution ratio by the orifice, A fuel cell system.

3. The fuel cell system according to claim 2, wherein the hydrogen blower, the orifice, and the combustion gas inlet of the fuel cell module are located above the first branch point, A fuel cell system.

4. The fuel cell system according to claim 2, A condensate line that branches off from the hydrogen off-gas line at a second branch point downstream of the heat exchanger and through which condensate obtained by condensing the hydrogen off-gas in the heat exchanger flows. The second branch point is located at the same position as the first branch point or below the first branch point. Fuel cell system.

5. The fuel cell system according to claim 4, Comprising a condensate tank for storing condensate. The second branch point is located below the hydrogen off-gas outlet of the heat exchanger. The condensate tank is located below the second branch point. The condensate line extends downward from the second branch point and is connected to the condensate tank. Fuel cell system.

6. The fuel cell system according to claim 4, The second branch point is provided on the downstream side of the heat exchanger and upstream of the first branch point in the hydrogen off-gas line. Fuel cell system.

7. The fuel cell system according to claim 4, The hydrogen off-gas inlet of the heat exchanger is located below the hydrogen off-gas outlet of the fuel cell module. Fuel cell system.

Images