fuel cell system

Abstract

To provide a fuel cell system which can be stably used for a long period by correcting the deformation by determining a deformation state of a separator.SOLUTION: A fuel cell system comprises a cell stack 2 into which a plurality of battery cells is laminated, in which an anode chamber facing to an anode of a cell stack 2 and a cathode chamber facing to a cathode are divided by a separator, and a fuel pump 3 supplies an anode gas to the anode chamber, an air blower 7 supplies the cathode gas to the cathode chamber, and the fuel pump 3 and the air blower 7 are controlled by a controller 70. The controller 70 determines the deformation state of the separator on the basis of a state of a flow of the anode gas flowing in the anode chamber (and / or the cathode chamber) of the cell stack 2, and corrects the deformation state of the separator by controlling a pressure of the anode gas of the anode chamber in the cell stack 2 (a plurality of battery cells) on the basis of a result of this deformation determination.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fuel cell system in which the anode and cathode compartments of a plurality of cells are separated by a separator. [Background technology]

[0002] A fuel cell system has been proposed that includes a cell stack having multiple battery cells, each of which has an electrolyte layer, an anode (fuel electrode) disposed on one side of the electrolyte layer, and a cathode (oxygen electrode) disposed on the other side (see, for example, Patent Document 1). In this fuel cell system, the stack body of the cell stack is provided with a first inlet manifold and a first outlet manifold for anode gas, and the anode gas is supplied to the anode chambers of the multiple battery cells through the first inlet manifold, and the anode off-gas that flows through these anode chambers is discharged through the first outlet manifold. The stack body is also provided with a second inlet manifold and a second outlet manifold for cathode gas, and the cathode gas is supplied to the cathode chambers of the multiple battery cells through the second inlet manifold, and the cathode off-gas that flows through these cathode chambers is discharged through the second outlet manifold.

[0003] In this fuel cell system, a separator is provided to separate the anode and cathode chambers of each battery cell, and anode gas from the first inlet manifold flows through one side of the separator into the anode chamber of the battery cell before being discharged to the first outlet manifold, while cathode gas from the second inlet manifold flows through the other side of the separator into the cathode chamber of the battery cell before being discharged to the second outlet manifold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6945035 Summary of the Invention [Problem to be solved by the invention]

[0005] However, such fuel cell systems have the following problem due to the difference in gas pressure between the anode gas and cathode gas supplied to the battery cells: The pressure of the anode gas supplied to the anode side (anode chamber) of the battery cells is lower than the pressure of the cathode gas supplied to the cathode side (cathode chamber), and the difference in these gas pressures causes stress toward the anode side in the separators that separate the anode and cathode chambers and in the battery cells supported by them, and if this stress acts over a long period of time, there is a risk that the separators and the battery cells supported by them will become deformed.

[0006] For example, if the separator deforms toward the anode side, the anode chamber (anode flow path) narrows, increasing flow path resistance, reducing the flow rate of anode gas supplied to the anode chamber of the battery cell, and preventing a sufficient supply of anode gas to the anode chamber. This reduction in anode gas makes it difficult for the electrochemical reaction to proceed in the battery cell, and in some cases, a lack of anode gas can cause fuel starvation and damage to the battery cell, which has a negative impact on the durability and reliability of the cell stack.

[0007] For this reason, in Patent Document 1, gas distribution members are provided at the inlet and outlet portions of the separator for anode gas, and these gas distribution members prevent the separator from deforming toward the anode chamber, thereby suppressing an increase in flow path resistance. However, in this conventional configuration, it is necessary to provide a gas distribution member corresponding to each separator, and these gas distribution members increase flow path resistance and complicate the configuration of the cell stack itself.

[0008] The present invention provides a fuel cell system that can be used stably for a long period of time by determining the state of deformation of the separator and correcting the state of deformation. [Means for solving the problem]

[0009] A fuel cell system according to a first aspect of the present invention comprises: a cell stack having a plurality of battery cells, each having an ion-conducting electrolyte layer, an anode disposed on one side of the electrolyte layer, and a cathode disposed on the other side of the electrolyte layer; first and second inlet manifolds provided on the inlet side of a stack body of the cell stack; first and second outlet manifolds provided on the outlet side of the stack body; a separator for separating an anode chamber facing the anode and a cathode chamber facing the cathode; an anode gas supply means for supplying anode gas to the anode chambers of the plurality of battery cells through the first inlet manifold; a cathode gas supply means for supplying cathode gas to the cathode chambers of the plurality of battery cells through the second inlet manifold; and a controller for controlling the anode gas supply means and the cathode gas supply means. The controller includes a deformation determination means for determining the deformation state of the separator based on the flow state of the anode gas and / or cathode gas flowing in the anode chamber and / or the cathode chamber of the plurality of battery cells, and corrects the deformation state of the separator by controlling the pressure of the anode gas in the anode chamber of the plurality of battery cells based on the determination result of the deformation determination means.

[0010] In addition, in a fuel cell system according to claim 2 of the present invention, a first inlet pressure measuring means for measuring the pressure of the anode gas is provided in an anode gas supply flow path that supplies anode gas to the plurality of battery cells of the cell stack, and a first outlet pressure measuring means for measuring the pressure of the anode off gas is provided in an anode off gas discharge flow path that discharges anode off gas from the plurality of battery cells of the cell stack, and the deformation determination means is characterized in that it determines the deformation state of the separator based on the pressure difference between the pressure measured by the first inlet pressure measuring means and the pressure measured by the first outlet pressure measuring means.

[0011] In addition, in the fuel cell system described in claim 3 of the present invention, a second inlet pressure measuring means for measuring the pressure of the cathode gas is provided in a cathode gas supply flow path that supplies cathode gas to the multiple battery cells of the cell stack, and a second outlet pressure measuring means for measuring the pressure of the cathode offgas is provided in a cathode offgas discharge flow path that discharges cathode offgas from the multiple battery cells of the cell stack, and the deformation determination means is characterized in that it determines the deformation state of the separator based on the pressure difference between the pressure measured by the second inlet pressure measuring means and the pressure measured by the second outlet pressure measuring means.

[0012] In addition, in the fuel cell system described in claim 4 of the present invention, a generated voltage measuring means for measuring the generated voltage of the stack body is provided in association with the cell stack, and the deformation determining means is characterized in that it determines the deformation state of the separator based on the measured voltage of the generated voltage measuring means.

[0013] In addition, in the fuel cell system described in claim 5 of the present invention, the controller increases the pressure of the anode gas in the anode chamber in the plurality of battery cells based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing the increased gas pressure of the anode gas.

[0014] In addition, in the fuel cell system described in claim 6 of the present invention, the controller controls the anode gas supply means to increase the supply flow rate of the anode gas based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing the increase in gas pressure of the anode gas that accompanies the increase in supply flow rate.

[0015] In addition, in a fuel cell system according to a seventh aspect of the present invention, a bypass flow path having a throttle member is provided in the anode off-gas discharge flow path downstream of the first outlet-side manifold, bypassing a portion of the anode off-gas discharge flow path, and a flow path switching valve is provided at a connection between the anode off-gas discharge flow path and the bypass flow path on the upstream side, the flow path switching valve holds the anode off-gas discharge flow path in an open state and the bypass flow path in a closed state in a first switching state, and holds the anode off-gas discharge flow path in a closed state and the bypass flow path in an open state in a second switching state, and the controller switches the flow path switching valve to the second switching state based on the determination result of the deformation determination means, causing the anode off-gas from the cell stack to flow through the bypass flow path and the throttle member, and corrects the deformation of the separator by utilizing the increase in anode gas pressure caused by the flow rate restriction by the throttle member.

[0016] Furthermore, in the fuel cell system described in claim 8 of the present invention, the controller controls the cathode gas supply means to reduce the supply flow rate of the cathode gas based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing the decrease in gas pressure of the cathode gas that accompanies the decrease in supply flow rate. [Effects of the Invention]

[0017] According to the fuel cell system of the present invention, anode chambers facing the anodes of the multiple battery cells and cathode chambers facing the cathodes are separated by separators, and anode gas flowing through the first inlet manifold flows through the anode chambers of the multiple battery cells before being discharged to the first outlet manifold, and cathode gas flowing through the second inlet manifold flows through the cathode chambers of the multiple battery cells before being discharged to the second outlet manifold. The controller also includes a deformation determination means for determining the deformation state of the separator, and this deformation determination means makes its determination based on the flow state of anode gas and / or cathode gas flowing through the anode chambers and / or cathode chambers of the multiple battery cells, making it possible to determine the deformation state of the separator.

[0018] For example, if the pressure of the anode gas flowing through the anode chamber is lower than the pressure of the cathode gas flowing through the cathode chamber, stress caused by this pressure difference acts on the separator and battery cell, causing the separator and battery cell to tend to deform toward the anode. If this stress causes the separator to deform toward the anode, for example, the anode chamber of the battery cell becomes narrower (the cathode chamber becomes wider), increasing (decreasing) the flow resistance of the anode chamber (cathode chamber) and decreasing (increasing) the flow rate of the anode gas (cathode gas). The greater the deformation of the separator, the greater (smaller) the flow resistance of the anode chamber (cathode chamber) and decreasing (increasing) the flow rate of the anode gas (cathode gas).

[0019] As a result, the degree of separator deformation can be determined from the flow state of anode gas (cathode gas) flowing through the anode chamber (cathode chamber), and the deformation determination means determines the separator deformation state from this anode gas (cathode gas) flow state.The controller then controls the anode gas pressure in the anode chambers of multiple battery cells based on this determination result, so that the anode gas pressure can be used to correct the separator deformation state and return the separator to close to its original state.

[0020] Furthermore, according to the fuel cell system of claim 2 of the present invention, a first inlet pressure measuring means is provided in the anode gas supply flow path, and a first outlet pressure measuring means is provided in the anode off-gas discharge flow path. Therefore, the first inlet pressure measuring means and the first outlet pressure measuring means can detect the gas pressures upstream and downstream of the anode chambers of multiple battery cells, and the deformation state of the separator can be determined based on the pressure difference between these measured pressures.

[0021] For example, a large pressure difference between the pressure measured by the first inlet pressure measuring means and the pressure measured by the first outlet pressure measuring means means that the flow path resistance of the anode chambers of multiple battery cells is large, in other words, that the separator is significantly deformed toward the anode side.In such a case, the deformation determination means determines the deformation of the separator based on the pressure difference between the measured pressures.

[0022] Furthermore, according to the fuel cell system of claim 3 of the present invention, a second inlet pressure measuring means is provided in the cathode gas supply flow path, and a second outlet pressure measuring means is provided in the cathode off-gas discharge flow path. Therefore, the second inlet pressure measuring means and the second outlet pressure measuring means can detect the gas pressures upstream and downstream of the cathode chambers of multiple battery cells, and the deformation state of the separator can be determined based on the pressure difference between these measured pressures.

[0023] For example, if the pressure difference between the pressure measured by the second inlet pressure measuring means and the pressure measured by the second outlet pressure measuring means is small, this means that the flow path resistance of the cathode chambers of the multiple battery cells is small; in other words, the separator is significantly deformed toward the anode side, reducing the flow path resistance of the cathode chamber. In such a case, the deformation determination means determines the deformation of the separator based on this pressure difference between the measured pressures.

[0024] Furthermore, according to the fuel cell system of claim 4 of the present invention, the cell stack is provided with a generated voltage measuring means for measuring the generated voltage of the stack body, and the deformation state of the separator can also be determined based on the measured voltage of this generated voltage measuring means.

[0025] For example, a decrease in the power generation voltage of a cell stack means that the flow resistance of the anode chambers of multiple battery cells has increased, causing a decrease in the supply flow rate of anode gas supplied to these anode chambers; in other words, the separator has deformed significantly toward the anode side.In such a case, the deformation determination means determines the deformation of the separator based on this measured voltage.

[0026] Furthermore, according to the fuel cell system of the present invention described in claim 5, the controller increases the pressure of the anode gas in the anode chambers of the plurality of battery cells based on the determination result of the deformation determination means, and this increased gas pressure of the anode gas can be used to correct the deformation state of the separators to close to their original state.

[0027] Furthermore, according to the fuel cell system of claim 6 of the present invention, the controller controls the anode gas supply means to increase the supply flow rate of the anode gas based on the determination result of the deformation determination means, and therefore, the increase in the gas pressure of the anode gas that accompanies this increase in the supply flow rate can be utilized to correct the deformation state of the separator.

[0028] Furthermore, according to a fuel cell system of the present invention, a bypass flow path having a throttling member is provided so as to bypass a portion of the anode off-gas discharge flow path, and a flow path switching valve is provided at the connection between this anode off-gas discharge flow path and the upstream side of the bypass flow path, and the controller switches this flow path switching valve from the first switching state to the second switching state based on the determination result of the deformation determination means, so that the anode off-gas from the cell stack flows through the bypass flow path and the throttling member, and the increase in gas pressure of the anode off-gas due to the flow rate restriction of this throttling member can be used to correct the deformation state of the separator.

[0029] Furthermore, according to the fuel cell system of claim 8 of the present invention, the controller controls the cathode gas supply means to reduce the supply flow rate of the cathode gas based on the determination result of the deformation determination means, so that the reduction in cathode gas pressure that accompanies the reduction in supply flow rate can be additionally utilized to correct the deformation state of the separator. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a block diagram showing a simplified first embodiment of a fuel cell system according to the present invention; [Figure 2] FIG. 2 is a simplified cross-sectional view of the cell stack of the fuel cell system of FIG. 1, cut at a portion through which anode gas flows. [Figure 3] FIG. 2 is a simplified cross-sectional view of the cell stack of the fuel cell system of FIG. 1, cut at a portion through which cathode gas flows. [Figure 4] FIG. 2 is a simplified block diagram showing a control system of the fuel cell system of FIG. 1. [Figure 5] 5 is a flowchart showing the flow of control by the control system of FIG. 4; [Figure 6] FIG. 3 is a simplified block diagram showing a second embodiment of a fuel cell system according to the present invention. [Figure 7] FIG. 7 is a simplified block diagram showing a control system of the fuel cell system of FIG. 6. [Figure 8] 8 is a flowchart showing the flow of control by the control system of FIG. 7; DETAILED DESCRIPTION OF THE INVENTION

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a fuel cell system according to the present invention will be described with reference to the accompanying drawings. First, a first embodiment of a fuel cell system according to the present invention will be described with reference to FIGS.

[0032] 1, the fuel cell system of the first embodiment includes a cell stack 2 that generates electricity through an electrochemical reaction between an anode gas (fuel gas such as hydrogen) and a cathode gas (oxidant gas such as air), and an anode gas supply flow path 4 that supplies the anode gas (fuel gas) and a cathode gas supply flow path 6 that supplies the cathode gas (oxidant gas) are connected to the inlet side of the cell stack 2. Also, an anode off-gas discharge flow path 8 that discharges the anode off-gas and a cathode off-gas discharge flow path 10 that discharges the cathode off-gas are connected to the outlet side of the cell stack 2.

[0033] Anode gas supplying means, such as a fuel pump 3, is disposed in the anode gas supplying flow path 4, and the action of this fuel pump 3 causes anode gas from an anode gas supply source 5 to be supplied to the cell stack 2 through the anode gas supplying flow path 4. Furthermore, cathode gas supplying means, such as an air blower 7, is disposed in the cathode gas supplying flow path 6, and the action of this air blower 7 causes cathode gas to be supplied to the cell stack 2 through the cathode gas supplying flow path 6.

[0034] 2 and 3, the cell stack 2 is composed of a plurality of battery cells 12 stacked vertically in FIGS. 2 and 3, and each battery cell 12 is composed of a flat cell of substantially the same shape. Each battery cell 12 includes an ion-conducting electrolyte layer 14, an anode 16 (fuel electrode) disposed on one side of the electrolyte layer 14 (the lower side in FIGS. 2 and 3), and a cathode 18 (oxygen electrode) disposed on the other side of the electrolyte layer 14 (the upper side in FIGS. 2 and 3). Interconnectors 20 are disposed between each battery cell 12, and although not specifically shown, the battery cells 12 are electrically connected via these interconnectors 20. For example, a solid oxide fuel cell (SOFC) using a solid oxide as the electrolyte layer 14 can be used as the battery cell 12.

[0035] The cell stack 2 includes a rectangular stack body 22, which is composed of multiple plate-like members (not shown). A rectangular opening 24 is provided in the center of the stack body 22, and multiple stacked battery cells 12 are arranged within this opening 24. The outer periphery of each battery cell 12 is fixed to a first separator 26, and the outer periphery of this first separator 26 is attached to the stack body 22, for example, between the inner peripheries of vertically adjacent plate-like members (not shown). The outer periphery of the interconnector 20 is fixed to a second separator 28, and the outer periphery of this second separator 28 is attached to the stack body 22, for example, between vertically adjacent plate-like members (not shown). The first and second separators 26, 28 are composed of, for example, thin metal plates.

[0036] 2 and 3, in this embodiment, an electrolyte layer 14 is provided on the surface side of the anode 16 of each battery cell 12, and a cathode 18 is provided on the surface side of this electrolyte layer 14. The outer periphery of the anode 16 protrudes outward from the outer peripheries of the electrolyte layer 14 and the cathode 18, and the inner periphery of a first separator 26 is fixed to this protruding portion.

[0037] With this configuration, an anode chamber 30 is defined on the anode 16 side of the electrolyte layer 14, and a cathode chamber 32 is defined on the cathode 18 side of the electrolyte layer 14. The anode chamber 30 and cathode chamber 32 of the battery cell 12 are separated by a first separator 26, and the first separator 26 is attached to the stack body 22 to prevent gas leakage between the anode chamber 30 and the cathode chamber 32. Adjacent battery cells 12 are separated by an interconnector 20 and a second separator 28, and the second separator 28 is attached to the stack body 22 to prevent gas leakage between adjacent battery cells 12.

[0038] 2, a first inlet-side manifold 34 is provided on one side (the left side in FIG. 2) of the stack body 22, and a first outlet-side manifold 36 is provided on the other side (the right side in FIG. 2), with the first inlet-side manifold 34 and the first outlet-side manifold 36 extending in the stacking direction of the battery cells 12 (the vertical direction in FIGS. 2 and 3). The first inlet-side manifold 34 is provided with an anode gas communication passage 38 that communicates with the anode chambers 30 of each battery cell 12, and the first outlet-side manifold 36 is provided with an anode off-gas communication passage 40 that communicates with the anode chambers 30 of each battery cell 12.

[0039] As shown by the arrows in Figure 2, the anode gas from the anode gas supply passage 4 (see Figure 1) is supplied to the first inlet-side manifold 34 of the stack body 22, and after being distributed by this first inlet-side manifold 34, is delivered to the anode chamber 30 of the corresponding battery cell 12 through an anode gas communication passage 38. In addition, the anode off-gas discharged from the anode chamber 30 of each battery cell 12 flows through an anode off-gas communication passage 40 to the first outlet-side manifold 36, and is further discharged through an anode off-gas discharge passage 8 (see Figure 1).

[0040] 3, a second inlet-side manifold 42 is provided on one side of the stack body 22 (the left side in FIG. 3, a location different from the first inlet-side manifold 34), and a second outlet-side manifold 44 is provided on the other side (the right side in FIG. 3, a location different from the first outlet-side manifold 36). The second inlet-side manifold 42 and the second outlet-side manifold 44 extend in the stacking direction of the battery cells 12 (the vertical direction in FIGS. 2 and 3), similar to the first inlet-side manifold 34 and the first outlet-side manifold 36. The second inlet-side manifold 42 is provided with a cathode gas communication channel 46 that communicates with the cathode chambers 32 of each battery cell 12, and the second outlet-side manifold 44 is provided with a cathode off-gas communication channel 48 that communicates with the cathode chambers 32 of each battery cell 12.

[0041] The cathode gas from the cathode gas supply passage 6 (see FIG. 1) is supplied to the second inlet manifold 42 of the stack body 22 as shown by the arrows in FIG. 3, and after being distributed by this second inlet manifold 42, is delivered to the cathode chamber 32 of the corresponding battery cell 12 through the cathode gas communication passage 46. In addition, the cathode off-gas discharged from the cathode chamber 32 of each battery cell 12 flows to the second outlet manifold 44 through the cathode off-gas communication passage 48, and is further discharged through the cathode off-gas discharge passage 10 (see FIG. 1).

[0042] Returning to FIG. 1 , in this fuel cell system, the cell stack 2 is housed in a high-temperature space 52 within a hot module 50 and maintained at a high temperature. As described above, the anode gas from the anode gas supply flow path 4 is supplied to the anode chamber 30 of each battery cell 12 through the first inlet manifold 34 of the stack body 22 (see FIG. 2 ), and the cathode gas from the cathode supply flow path 6 is supplied to the cathode chamber 32 of each battery cell 12 through the second inlet manifold 42 of the stack body 22 (see FIG. 3 ). Electricity is generated by an electrochemical reaction between the anode gas in the anode chamber 30 and the cathode gas in the cathode chamber 32, and the generated power in each battery cell 12 is collected via the interconnector 20. The generated power from the cell stack 2 is sent to an inverter 56 through a power generation output line 54, where it is converted from direct current to alternating current and then sent to an electric power load (not shown), such as a lighting device or a home appliance.

[0043] In such a fuel cell system, the pressure of the anode gas supplied through the anode gas supply passage 4 is set to be lower than the pressure of the cathode gas supplied through the cathode gas supply passage 6. As a result, in each battery cell 12, the pressure inside the anode chamber 30 (anode gas pressure) is lower than the pressure inside the cathode chamber 32 (cathode gas pressure). Due to this lower pressure, stress acts on the battery cell 12 toward the anode 16, and the first separator 26 supporting the battery cell 12 tends to deform toward the anode 16.

[0044] Furthermore, in the structure of the illustrated cell stack 2, the anode chamber 30 of one adjacent battery cell 12 (e.g., the upper side in Figures 2 and 3) and the cathode chamber 32 of the other adjacent battery cell 12 (e.g., the lower side in Figures 2 and 3) are connected via an interconnector 20, and therefore, due to the pressure difference between the anode gas and the cathode gas, stress acts on this interconnector 20 toward one of the battery cells 12, and the second separator 28 supporting the interconnector 20 tends to deform toward one of the battery cells 12.

[0045] When the pressure difference between the anode gas and the cathode gas causes deformation of the first separator 26 supporting the battery cell 12 and / or the second separator 28 supporting the interconnector 20, the anode chamber 30 (the gap between the anode 16 and the interconnector 20) of the battery cell 12 narrows, which increases the flow resistance of the anode chamber 30 and reduces the flow of the anode gas, as can be seen from Figures 2 and 3. This causes the cathode chamber 32 (the gap between the cathode 18 and the interconnector 20) of the battery cell 12 to widen, which reduces the flow resistance of the cathode chamber 32.

[0046] This fuel cell system is configured as follows to correct deformation of the first separator 26 and / or second separator 28 that occurs as described above. More specifically, a first inlet pressure sensor 62 (constituting first inlet pressure measurement means) is provided in the anode gas supply flow path 4, and a first outlet pressure sensor 64 (constituting first outlet pressure measurement means) is provided in the anode off-gas discharge flow path 8. The first inlet pressure sensor 62 measures the pressure of the anode gas upstream of the cell stack 2 (plurality of battery cells 12), and the first outlet pressure sensor 64 measures the pressure of the anode gas (anode off-gas) downstream of the cell stack 2. The greater the deformation of the first separator 26 and / or second separator 28, the narrower the flow path of the anode chamber 30 of the battery cell 12 becomes, increasing flow path resistance. This increases the pressure difference between the pressure measured by the first inlet pressure sensor 62 and the pressure measured by the first outlet pressure sensor 64.

[0047] Furthermore, a second inlet pressure sensor 66 (constituting second inlet pressure measuring means) is provided in the cathode gas supply flow path 6, and a second outlet pressure sensor 68 (constituting second outlet pressure measuring means) is provided in the cathode offgas discharge flow path 10. The second inlet pressure sensor 66 measures the pressure of the cathode gas upstream of the cell stack 2 (plurality of battery cells 12), and the second outlet pressure sensor 68 measures the pressure of the cathode gas (cathode offgas) downstream of the cell stack 2. As the deformation of the first separator 26 and / or the second separator 28 increases, the cathode chamber 32 of the battery cell 12 becomes wider and the flow path resistance decreases, so the pressure difference between the pressure measured by the second inlet pressure sensor 66 and the pressure measured by the second outlet pressure sensor 68 decreases.

[0048] Measurement signals from the first and second inlet pressure sensors 62, 66 and the first and second outlet pressure sensors 64, 68 are sent to a controller 70 that controls the fuel cell system, and this controller 70 controls the fuel pump 3 and the like as follows. Referring to Fig. 4, the controller 70 is composed of, for example, a microprocessor, and includes pressure difference calculation means 72, calculated pressure difference comparison means 74, deformation determination means 76, flow rate increase signal generation means 78, correction determination means 80, flow rate return signal generation means 82, and control means 84, and these various means 72 to 84 function according to control software installed in the controller 70. The controller 70 also includes memory means 86, and this memory means 86 stores a deformation reference pressure difference value that serves as a reference for determining the deformation state of the first separator 26 and / or the second separator 28, a correction reference pressure difference value that serves as a reference for determining the correction state of the first separator 26 and / or the second separator 28, and the like.

[0049] In this embodiment, the deformation state of the first separator 26 and / or the second separator 28 is detected based on changes in the flow path resistance of the anode chamber 30 of the battery cell 12, and in connection with this, the following control is performed using the pressures measured by the first inlet pressure sensor 62 and the first outlet pressure sensor 64. Note that when detecting the deformation state of the first separator 26 and / or the second separator 28 based on changes in the flow path resistance of the cathode chamber 32 of the battery cell 12, the pressures measured by the second inlet pressure sensor 66 and the second outlet pressure sensor 68 are used.

[0050] The pressure difference calculation means 72 calculates the pressure difference between the pressure measured by the first inlet side pressure sensor 62 (first inlet side pressure measurement means) and the pressure measured by the first outlet side pressure sensor 64 (first outlet side pressure measurement means), and the calculated pressure difference comparison means 74 compares this calculated pressure difference with a deformation reference pressure difference value in the memory means 86 when detecting a deformed state, and compares this calculated pressure difference with a corrected reference pressure difference value in the memory means 86 when detecting a corrected state.

[0051] When the pressure difference calculated by the pressure difference calculation means 72 becomes larger than the deformation reference pressure difference value stored in the memory means 86, the deformation determination means 76 determines that deformation has occurred in the first separator 26 and / or the second separator 28, and the flow rate increase signal generation means 78 generates a flow rate increase signal based on this deformation determination. Furthermore, when the pressure difference calculated by the pressure difference calculation means 72 becomes smaller than the corrected reference pressure difference value stored in the memory means 86, the correction determination means 80 determines that the deformation occurring in the first separator 26 and / or the second separator 28 has been corrected, and the flow rate return signal generation means 82 generates a flow rate return signal based on this correction determination. Furthermore, the control means 84 controls the fuel pump 3 (anode gas supply means) based on the flow rate increase signal and the flow rate return signal, as described below.

[0052] Next, fuel flow control of the above-mentioned fuel cell system will be described mainly with reference to Figures 1, 4, and 5. To detect the deformation state of the first separator 26 and / or the second separator 28, for example, operation of the fuel cell system for detecting the deformation state is started (step S1). Note that instead of performing such operation for detection, the deformation state may be detected during power generation operation of the fuel cell system.

[0053] When the fuel cell system starts operating, the pressures on the inlet and outlet sides of the anode gas are detected (step S2). The first inlet pressure sensor 62 measures the pressure of the anode gas flowing on the anode 16 side of the cell stack 2 (plurality of battery cells 12) (the pressure in the anode gas supply flow path 4), and the first outlet pressure sensor 64 measures the pressure of the anode gas (anode off-gas) discharged from the anode side 16 of the cell stack 2 (the pressure in the anode off-gas discharge flow path 8). Measurement signals from the first inlet pressure sensor 62 and the first outlet pressure sensor 64 are sent to the controller 70.

[0054] When the measurement signal is sent in this manner, the pressure difference calculation means 72 calculates the pressure difference between the pressure measured by the first inlet side pressure sensor 62 and the pressure measured by the first outlet side pressure sensor 64 (step S3), and uses this calculated pressure difference to compare it with the deformation reference pressure difference value.The calculated pressure difference comparison means 74 compares the pressure difference calculated by the pressure difference calculation means 72 with the deformation reference pressure difference value in the memory means 86 to detect the deformation state of the first separator 26 and / or the second separator 28.

[0055] If this calculated pressure difference becomes larger than the deformation reference pressure difference value (calculated pressure difference > deformation reference pressure difference value), the process proceeds from step S4 to step S5, and the deformation determination means 76 performs deformation determination as described above. If this calculated pressure difference becomes larger than the deformation reference pressure difference, this means that the flow path resistance on the anode 16 side of the cell stack 2 has increased (in other words, the anode chambers 30 of the multiple battery cells 12 have become narrower), making it difficult for the anode gas to flow, which is caused by deformation of the first separator 26 and / or second separator 28, and therefore separator deformation determination is performed.

[0056] When this deformation determination is made, the flow rate increase signal generating means 78 generates a flow rate increase signal (step S6), and the control means 84 controls the rotation speed of the fuel pump 3 to increase based on this flow rate increase signal. As a result, the supply flow rate of the anode gas supplied to the anode chamber 30 (see FIGS. 2 and 3) of the cell stack 2 (plurality of battery cells 12) through the anode gas supply flow path 4 increases, and the gas pressure increases. The anode gas with increased gas pressure acts on the first and second separators 26, 28, and the increased gas pressure of the anode gas corrects the deformation of the first separator 26 and / or the second separator 28 so that it returns to nearly its original state. In this way, the deformation of the first and second separators 26, 28 is corrected (step S7).

[0057] When the first and second separators 26, 28 are deformed and corrected in this manner, the anode chambers 30 of the cell stack 2 (plurality of battery cells 12) become wider, the flow resistance of these anode chambers 30 decreases, and the flow of anode gas improves.

[0058] Then, when the flow of anode gas is improved and the pressure difference (pressure difference calculated by the pressure difference calculation means 72) between the anode gas pressure on the upstream side of the cell stack 2 (pressure measured by the first inlet-side pressure sensor 62) and the anode gas pressure on the downstream side (pressure measured by the second outlet-side pressure sensor 64) becomes smaller than the corrected reference pressure difference value registered in the memory means 86 (calculated pressure difference<corrected reference pressure difference value), the process proceeds from step S8 to step S9, and the correction determination means 80 performs a correction determination as described above. The fact that this calculated pressure difference becomes smaller than the corrected reference pressure difference means that the deformation state of the first separator 26 and / or the second separator 28 has been corrected to close to its original state, the anode chamber 30 (see Figures 2 and 3) of the cell stack 2 (plurality of battery cells 12) has become wider, its flow path resistance has decreased, and the anode gas flow has returned to approximately its original state, and as a result, a separator correction determination is performed. In step S4, if the calculated pressure difference is equal to or less than the modified reference pressure difference value (calculated pressure difference≦modified reference pressure difference value), the process proceeds from step S4 to step S8.

[0059] When the correction determination is made in this manner, the correction of the deformation of the first and second separators 26, 28 due to the increase in the anode gas flow rate is completed (step S10), and the flow rate return signal generating means 82 generates a flow rate return signal based on the result of this correction determination (step S11). Then, the control means 84 returns the rotation speed of the fuel pump 3 to its original rotation speed based on this flow rate return signal, and thus the supply flow rate of the anode gas returns to its original state (step S12), and the operation of the fuel cell system for detecting the deformation state of the separators and correcting it is completed (step S13).

[0060] Furthermore, in step S8, if the calculated pressure difference by the pressure difference calculation means 72 is greater than or equal to the corrected standard pressure difference value (calculated pressure difference ≧ corrected standard pressure difference value), the process proceeds from step S8 to step S14, and if a predetermined time has not elapsed since the start of operation of the fuel cell system, the process returns to step S2 and steps S2 to S8 are repeated, but once the predetermined time has elapsed, the process proceeds from step S14 to step S11, the flow rate return signal generation means 82 generates a flow rate return signal, the supply flow rate of the anode gas returns to its original state, and the operation of the fuel cell system for detecting the deformation state of the separator and correcting it is terminated.

[0061] In the above-described embodiment, the present invention has been described as being applied to a cell stack 2 in which the battery cells 12 and the interconnectors 20 are attached to the stack body 22 via the first and second separators 26, 28. However, the present invention is not limited to this configuration and can also be applied to a configuration in which only the battery cells 12 are attached to the stack body 22 via the first separator 26. In this case, the first separator 26 supporting the battery cells 12 will be deformed.

[0062] In the above-described embodiment, a flow rate increase signal is generated to increase the supply flow rate of anode gas based on the determination of separator deformation. However, in addition to this flow rate increase signal, a flow rate decrease signal to decrease the supply flow rate of cathode gas may also be generated. In this case, the controller 70 further includes a flow rate decrease signal generating means (not shown), and based on the above-described deformation determination, the increase signal generating means 78 generates a flow rate increase signal, and based on this flow rate increase signal, the rotation speed of the fuel pump 3 (anode gas supply means) increases to increase the supply flow rate of anode gas, and the flow rate decrease signal generating means generates a flow rate decrease signal, and based on this flow rate decrease signal, the rotation speed of the air blower 7 (cathode gas supply means) decreases to decrease the supply flow rate of cathode gas. By controlling in this manner, it is possible to effectively correct the deformation state of the first separator 26 and / or the second separator 28.

[0063] Furthermore, in the above-described embodiment, deformation of the first separator 26 and / or the second separator 28 is detected based on pressure fluctuations in the anode gas upstream and downstream of the anode 16 (anode chamber 30 of the multiple battery cells 12) of the cell stack 2, but instead of this configuration, deformation of the first separator 26 and / or the second separator 28 may be detected based on pressure fluctuations in the cathode gas upstream and downstream of the cathode 18 (cathode chamber 32 of the multiple battery cells 12) of the cell stack 2. In this case, the measured pressures of the second inlet pressure sensor 66 of the cathode gas supply flow path 6 and the second outlet pressure sensor 68 of the cathode off-gas discharge flow path 10 are used.

[0064] When using pressure fluctuations in the cathode gas, as can be easily understood from the above explanation, the pressure difference calculation means 72 calculates the pressure difference between the pressure of the cathode gas upstream of the cathode 18 of the cell stack 2 (cathode chamber 32 of the multiple battery cells 12) (pressure measured by the second inlet pressure sensor 66) and the pressure of the cathode gas downstream of that cathode 18 (pressure measured by the second outlet pressure sensor 68), and the deformation determination means 76 determines that the separator is deformed when this calculated pressure difference is smaller than the deformation reference pressure difference value (calculated pressure difference<deformation reference pressure difference value), and the flow rate increase signal generation means 78 generates a flow rate increase signal based on this deformation determination.

[0065] Furthermore, if the pressure difference (calculated pressure difference by the pressure difference calculation means 72) between the cathode gas upstream and downstream of the cathode 18 of the cell stack 2 becomes larger than the corrected reference pressure difference value (calculated pressure difference > deformation reference pressure difference value) during the deformation correction of the separator, the correction determination means 80 makes a correction determination that the deformation state of the first and second separators 26, 28 has been corrected, and based on this correction determination, the flow rate return signal generation means 82 generates a flow rate return signal.

[0066] In this way, even if pressure fluctuations upstream and downstream of the cathode 18 (cathode chamber 32) of the cell stack 2 are used instead of pressure fluctuations of the anode gas upstream and downstream of the anode 16 (anode chamber 30) of the cell stack 2, it is possible to detect the deformation state of the first separator 26 and / or the second separator 28 and correct the deformation state, as described above.

[0067] As can be understood from the above description, deformation of the first separator 26 and / or the second separator 28 may be detected based on pressure fluctuations of the cathode gas upstream and downstream of the cathode 18 (cathode chamber 32 of the multiple battery cells 12) in addition to pressure fluctuations of the anode gas upstream and downstream of the anode 16 (anode chamber 30 of the multiple battery cells 12) of the cell stack 2.

[0068] Next, a second embodiment of a fuel cell system will be described with reference to Figures 6 to 8. In this second embodiment, instead of detecting the separator deformation state using fluctuations in the anode gas (cathode gas) pressure on the upstream and downstream sides of the cell stack, the separator deformation state is detected using fluctuations in the power generation voltage of this second cell stack. Also, in this second embodiment, instead of correcting the separator deformation state by increasing the supply flow rate of anode gas from the fuel pump (anode gas supply means), the flow resistance of the anode off-gas discharge flow path is increased to increase the anode gas pressure in the anode chamber, thereby correcting the separator deformation state. In this second embodiment, components that are substantially the same as those in the first embodiment described above are designated by the same reference numerals, and their description will be omitted.

[0069] 6 and 7, in the fuel cell system of this second embodiment, a voltage measuring device 92 is provided on the power generation output line 54 as a power generation voltage measuring means, and this voltage measuring device 92 measures the voltage of the power generation output output from the cell stack 2, and the measurement signal from this voltage measuring device 92 is sent to the controller 70A (see FIG. 7).

[0070] Furthermore, a bypass flow path 94 is provided to bypass a portion of the anode off-gas discharge flow path 10 through which the anode off-gas flows from the cell stack 2, and a throttle member 96 that restricts the flow of the anode off-gas is disposed in this bypass flow path 94. Furthermore, a flow path switching valve 98 is disposed at the connection portion that connects the anode off-gas discharge flow path 10 with the upstream side of the bypass flow path 94, and this flow path switching valve 98 can be, for example, a three-way switching valve.

[0071] In this embodiment, the flow path switching valve 98 is configured to be selectively switched between a first switching state and a second switching state, and when this flow path switching valve 98 is in the first switching state, the anode off-gas discharge flow path 10 is held in an open state and the bypass flow path 94 is held in a closed state, and anode off-gas from the anode of the cell stack 2 is discharged downstream through the anode off-gas discharge flow path 10, as shown by the solid arrow in Fig. 6. When this flow path switching valve 98 is in the second switching state, the anode off-gas discharge flow path 10 is held in a closed state and the bypass flow path 94 is held in an open state, and anode off-gas from the anode of the cell stack 2 flows through the bypass flow path 94 and then is discharged through the anode off-gas discharge flow path 10, as shown by the dashed arrow in Fig. 6.

[0072] In this regard, a controller 70A in a fuel cell system of the second embodiment is configured, for example, as shown in Fig. 7. In Fig. 7, this controller 70A uses generated voltage comparison means 100 that compares generated voltages from the cell stack 2 (voltages measured by a voltage measurement device 92) instead of the pressure difference calculation means and calculated pressure difference comparison means, and uses modified reference voltage values ​​and modified reference voltage values ​​instead of the modified reference pressure difference value and modified reference pressure difference value, and these modified reference voltage values ​​and modified reference voltage values ​​are registered in memory means 86A. This controller 70A further uses switching signal generation means 102 that generates a switching signal for switching the flow path switching valve 98 (three-way switching valve) from the first switching state to the second switching state instead of the flow rate increase signal generation means that generates a flow rate increase signal, and uses return signal generation means 104 that generates a return signal for switching the flow path switching valve 98 (three-way switching valve) from the second switching state to the first switching state instead of the flow rate return signal generation means that generates a flow rate return signal. The other configurations of the fuel cell system of this second embodiment are substantially the same as those of the first embodiment described above.

[0073] Next, fuel flow control of a fuel cell system according to a second embodiment will be described with reference to Figures 6, 7, and 8. When operation of the fuel cell system for detecting the deformation state of the first separator and / or second separator of the cell stack 2 (see Figures 2 and 3 of the first embodiment) begins (step S21), the output voltage of the cell stack 2 is measured (step S22). The voltage measurement device 92 detects the voltage (generated voltage) of the power output of the cell stack 2 (plurality of battery cells), and a measurement signal from the voltage measurement device 92 is sent to the controller 70A. The generated power comparison means 100 of the controller 70A compares this measured voltage with a deformation reference voltage value registered in the memory means 86A.

[0074] If the measured voltage of the voltage measuring device 92 becomes lower than the deformation reference voltage value (measured voltage<deformation reference voltage value), the process proceeds from step S23 to step S24, and the deformation determination means 76A determines that deformation has occurred in the separator. If this measured voltage becomes lower than the deformation reference voltage value, it means that the flow path resistance of the anode 16 (anode chamber) of the cell stack 2 has increased (in other words, the anode chamber of multiple battery cells has become narrower), making it difficult for the anode gas to flow and causing a drop in the generated voltage. This means that the first separator and / or second separator has deformed, and therefore separator deformation determination is performed.

[0075] When this deformation determination is made, the switching signal generating means 102 generates a switching signal (step S25), and the control means 84A switches the flow path switching valve 98 from the first switching state to the second switching state based on this switching signal (step S26). As a result, the anode off-gas discharge flow path 10 is switched to a closed state and the bypass flow path 94 is switched to an open state, and anode off-gas from the anode chamber (see Figures 2 and 3) of the cell stack 2 (plurality of battery cells) is discharged through the bypass flow path 94 and the anode off-gas discharge flow path 10.

[0076] At this time, the flow of anode off-gas is restricted by the throttle member 96, which causes the gas pressure in the anode chamber of the cell stack 2 (plurality of battery cells) to increase, and this increased anode gas pressure acts on the first and second separators (see FIGS. 2 and 3). Therefore, even in this configuration, as in the first embodiment, the increased anode gas pressure corrects the deformation of the first separator and / or second separator so that it returns to nearly its original state, and in this way the deformation of the first and second separators is corrected (step S27).

[0077] When the deformation of the first and second separators is corrected in this manner, the anode chamber of the cell stack 2 (multiple battery cells) becomes larger, the flow of anode gas improves, the power generation state of the cell stack 2 returns to almost its original state, and the power generation voltage of the cell stack 2 increases.

[0078] Then, when the generated voltage of the cell stack 2 rises and the generated voltage (the voltage measured by the voltage measuring device 92) becomes greater than the modified reference voltage value registered in the memory means 86A (measured voltage > modified reference voltage value), the process proceeds from step S28 to step S29, where the modification determination means 80A determines whether the separator needs to be modified. The fact that this measured voltage becomes greater than the modified reference voltage value means that the deformation state of the first separator and / or second separator (see FIGS. 2 and 3) has been modified to nearly its original state, the anode chamber (see FIGS. 2 and 3) of the cell stack 2 (multiple battery cells) has widened, and the anode gas flow has nearly returned to its original state. This triggers a determination to modify the separator. Note that in step S23, if the measured voltage is greater than or equal to the modified reference voltage value (measured voltage ≥ modified reference voltage value), the process proceeds from step S23 to step S28.

[0079] When the correction determination is made in this manner, the deformation correction of the first and second separators due to the anode off-gas discharge restriction is completed (step S30), and the return signal generating means 104 generates a return signal based on the determination result of this correction determination (step S31). Then, the control means 84A returns the flow path switching valve 98 from the second switching state to the first switching state based on this return signal, thereby discharging the anode off-gas from the cell stack 2 through the anode off-gas discharge flow path 10 (step S33), and thus the operation of the fuel cell system for detecting the deformation state of the separators and correcting it is completed (step S34).

[0080] In step S28, if the voltage measured by the voltage measuring device 92 is equal to or less than the corrected reference voltage value (measured voltage≦corrected reference voltage value), the process proceeds from step S28 to step S35. If a predetermined time has not elapsed since the start of operation of the fuel cell system, the process returns to step S22 and steps S22 to S28 are repeated. However, once the predetermined time has elapsed, the process proceeds from step S35 to step S31, the return signal generating means 104 generates a return signal, the flow of anode off-gas returns to its original state, and the operation of the fuel cell system for detecting the deformation state of the separator and correcting it is terminated.

[0081] In the second embodiment, the flow path switching valve 98 is configured as a three-way switching valve, but it may also be configured as two flow path switching valves, i.e., first and second flow path switching valves (not shown). In this case, the first flow path switching valve is disposed, for example, in the anode off-gas discharge flow path, and the second flow path switching valve is disposed, for example, in the bypass flow path 94. In the first switching state, the first flow path switching valve is held in an open state and the second flow path switching valve is held in a closed state. In the second switching state, the first flow path switching valve is held in a closed state and the second flow path switching valve is held in an open state.

[0082] Although the embodiments of the fuel cell system according to the present invention have been described above, the present invention is not limited to these embodiments, and various changes and modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0083] 2 Cell stack 3 Fuel pump (anode gas supply means) 4. Anode gas supply channel 6 Cathode gas supply channel 7 Air blower (cathode gas supply means) 8 Anode off-gas discharge passage 10 Cathode off-gas exhaust flow path 12 battery cells 14 Electrolyte layer 16 anodes 18 cathode 22 Stack body 26,28 Separator 30 Anode Chamber 32 Cathode chamber 62, 66 inlet pressure sensor (inlet pressure measuring means) 64, 68 Outlet pressure sensor (outlet pressure measuring means) 70,70A controller 72 Pressure difference calculation means 76, 76A Deformation determination means 78 Flow rate increase signal generating means 80,80A Correction judgment means 82 Flow rate return signal generating means 92 Voltage measuring device (means for measuring generated voltage) 94 Bypass flow path 96 Aperture member 98 Flow path switching valve 102 Switching signal generation means 104 Return signal generating means

Claims

1. a cell stack including a plurality of battery cells, each having an ion-conducting electrolyte layer, an anode disposed on one side of the electrolyte layer, and a cathode disposed on the other side of the electrolyte layer; first and second inlet manifolds provided on the inlet side of a stack body of the cell stack; first and second outlet manifolds provided on the outlet side of the stack body; a separator for separating an anode chamber facing the anode from a cathode chamber facing the cathode; an anode gas supply means for supplying anode gas to the anode chambers of the plurality of battery cells through the first inlet manifold; a cathode gas supply means for supplying cathode gas to the cathode chambers of the plurality of battery cells through the second inlet manifold; and a controller for controlling the anode gas supply means and the cathode gas supply means, the controller includes a deformation determination means for determining a deformation state of the separator based on a flow state of anode gas and / or cathode gas flowing in the anode chambers and / or cathode chambers of the plurality of battery cells, and corrects the deformation state of the separator by controlling the gas pressure of the anode gas flowing in the anode chambers of the plurality of battery cells based on the determination result of the deformation determination means.

2. 2. The fuel cell system according to claim 1, wherein a first inlet pressure measuring means for measuring the pressure of the anode gas is provided in an anode gas supply flow path that supplies anode gas to the plurality of battery cells of the cell stack, and a first outlet pressure measuring means for measuring the pressure of the anode off gas is provided in an anode off gas discharge flow path that discharges anode off gas from the plurality of battery cells of the cell stack, and the deformation determining means determines the deformation state of the separator based on the pressure difference between the pressure measured by the first inlet pressure measuring means and the pressure measured by the first outlet pressure measuring means.

3. 2. The fuel cell system according to claim 1, wherein a second inlet pressure measuring means for measuring the pressure of the cathode gas is provided in a cathode gas supply flow path that supplies cathode gas to the plurality of battery cells of the cell stack, and a second outlet pressure measuring means for measuring the pressure of the cathode offgas is provided in a cathode offgas discharge flow path that discharges cathode offgas from the plurality of battery cells of the cell stack, and the deformation determination means determines the deformation state of the separator based on a pressure difference between the pressure measured by the second inlet pressure measuring means and the pressure measured by the second outlet pressure measuring means.

4. 2. The fuel cell system according to claim 1, wherein a generated voltage measuring means for measuring a generated voltage of the stack body is provided in association with the cell stack, and the deformation determining means determines the deformation state of the separator based on the measured voltage of the generated voltage measuring means.

5. 5. The fuel cell system according to claim 1, wherein the controller increases the pressure of the anode gas in the anode chamber in each of the plurality of battery cells based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing the increased gas pressure of the anode gas.

6. 6. The fuel cell system according to claim 5, wherein the controller controls the anode gas supply means to increase the supply flow rate of the anode gas based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing the increase in gas pressure of the anode gas that accompanies the increase in the supply flow rate.

7. 6. The fuel cell system according to claim 5, wherein a bypass flow path having a throttle member is disposed in the anode off-gas discharge flow path downstream of the first outlet-side manifold, bypassing a portion of the anode off-gas discharge flow path, and a flow path switching valve is disposed at a connection between the anode off-gas discharge flow path and the bypass flow path on the upstream side, the flow path switching valve maintaining the anode off-gas discharge flow path in an open state and the bypass flow path in a closed state in a first switching state, and maintaining the anode off-gas discharge flow path in a closed state and the bypass flow path in an open state in a second switching state, and the controller switches the flow path switching valve to the second switching state based on a determination result of the deformation determination means, causing the anode off-gas from the cell stack to flow through the bypass flow path and the throttle member, and corrects the deformation of the separator by utilizing an increase in anode gas pressure due to the flow rate restriction by the throttle member.

8. 8. The fuel cell system according to claim 6, wherein the controller controls the cathode gas supply means to reduce the supply flow rate of the cathode gas based on the determination result of the deformation determination means, and corrects the deformation state of the separator by utilizing a decrease in the gas pressure of the cathode gas that accompanies the decrease in the supply flow rate.

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