JP7006158B2 - Fuel cell system - Google Patents

Description

The present invention relates to a fuel cell system.

In a fuel cell system, when starting below the freezing point, a warm-up operation is known in which the supply amount of the reaction gas supplied to the fuel cell stack having a plurality of single cells is reduced to warm the fuel cell stack. In the fuel cell system described in Patent Document 1, when the voltage value of a single cell decreases, it is determined that the gas flow path in the single cell is blocked due to freezing of the generated water.

International Publication No. 2011/021301

Factors that cause the voltage value of a single cell to drop include blockage due to freezing of the gas flow path in the single cell and blockage due to freezing of auxiliary parts. Processing may not be possible. Therefore, there has been a demand for a technique capable of reliably determining blockage due to freezing of the gas flow path in a single cell.

The present invention has been made to solve the above-mentioned problems, and can be realized as the following forms.
According to one embodiment of the present invention, a fuel cell system is provided. This fuel cell system includes a fuel cell stack having a plurality of single cells, a cell monitor that detects the cell voltage of the single cell, a temperature measuring unit that acquires the stack temperature of the fuel cell stack, and a stacking direction of the single cell. A reaction gas flow path in which the reaction gas is supplied from one end side to the other end side, a pressure detection unit for detecting the reaction gas pressure on the inlet side of the fuel cell stack of the reaction gas flow path, and a control unit. , Equipped with. The control unit is arranged on the other end side of the fuel cell stack when the stack temperature is below the freezing point and the reaction gas pressure is equal to or higher than a predetermined threshold voltage when the fuel cell system is started. When the cell voltage of the single cell is lower than the predetermined threshold voltage, it is determined that the reaction gas flow path in the single cell is blocked due to freezing, and the reaction gas pressure is equal to or higher than the threshold pressure. When the cell voltage of the single cell arranged on the other end side of the fuel cell stack is equal to or higher than the threshold voltage, other parts of the reaction gas flow path other than the inside of the single cell are blocked by freezing. Judge that it was done.

According to one embodiment of the present invention, a fuel cell system is provided. This fuel cell system includes a fuel cell stack having a plurality of single cells; a cell monitor that detects the cell voltage of the single cell; a temperature measuring unit that acquires the stack temperature of the fuel cell stack; and a stacking direction of the single cell. A reaction gas flow path to which the reaction gas is supplied from one end side to the other end side; a pressure detection unit for detecting the reaction gas pressure at the inlet side of the fuel cell stack of the reaction gas flow path; and a control unit. , Equipped with. The control unit is arranged on the other end side of the fuel cell stack when the stack temperature is below the freezing point and the reaction gas pressure is equal to or higher than a predetermined threshold pressure when the fuel cell system is started. When the cell voltage of the single cell is lower than the predetermined threshold voltage, it is determined that the reaction gas flow path in the single cell is blocked due to freezing. According to this form of the fuel cell system, the control unit determines whether or not the reaction gas flow path in the single cell is frozen by using the reaction gas pressure on the inlet side and the voltage of the single cell arranged on the other end side. Since freezing of the generated water is likely to occur in the single cell on the other end side, it is possible to reliably determine the blockage due to freezing of the gas flow path in the single cell.

The present invention can be realized in various forms, for example, a power generation device including a fuel cell system, a vehicle equipped with a fuel cell system, a control method of the fuel cell system, and the like. Is.

It is a schematic diagram which shows the schematic structure of the fuel cell system. It is a top view of a single cell in which the inside of the single cell is frozen. It is a flowchart which shows an example of the procedure of a freeze determination process. It is a timing chart which showed an example of the relationship between the stack temperature, the reaction gas pressure, and the reaction gas flow rate when there is no freezing in a single cell. It is a figure which showed the relationship between a cell number and a cell voltage when there is no freezing in a single cell. It is a timing chart which showed an example of the relationship between the stack temperature, the reaction gas pressure, and the reaction gas flow rate when there is freezing in a single cell. It is a figure which showed the relationship between a cell number and a cell voltage when there is a freeze in a single cell. It is a flowchart which shows an example of the procedure at the time of freezing.

A. First Embodiment:
FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system 100 according to an embodiment of the present invention. The fuel cell system 100 includes a fuel cell stack 10, a control unit 20, a cathode gas supply unit 30, an anode gas supply unit 50, and a cooling medium circulation unit 70. Further, the fuel cell system 100 includes a DC / DC converter 80, a power control unit (hereinafter referred to as “PCU”) 81, a load 82, and a cell monitor 83. The fuel cell system 100 of the present embodiment is mounted on, for example, a fuel cell vehicle.

The fuel cell stack 10 is a polymer electrolyte fuel cell that generates electricity by being supplied with an anode gas (for example, hydrogen gas) and a cathode gas (for example, air) as reaction gases. The fuel cell stack 10 is configured by stacking a plurality of single cells 11. Each single cell 11 sandwiches a membrane electrode assembly (not shown) in which an anode (not shown) and a cathode (not shown) are arranged on both sides of an electrolyte membrane (not shown) and a membrane electrode assembly. It has a set of separators (not shown).

The control unit 20 is configured as a computer including a CPU, a memory, and an interface circuit to which each component described later is connected. The control unit 20 outputs a signal for controlling the start and stop of each device in the fuel cell stack 10 in response to an instruction from the ECU (Electronic Control Unit) 21. The ECU 21 is a control unit that controls the entire device (for example, a vehicle) including the fuel cell system 100. For example, in a fuel cell vehicle, the ECU 21 controls the vehicle according to a plurality of input values such as the amount of depression of the accelerator pedal, the amount of depression of the brake pedal, and the vehicle speed. The ECU 21 may be included in a part of the functions of the control unit 20. The control unit 20 controls the power generation by the fuel cell system 100 by executing the control program stored in the memory, and realizes the warm-up operation and the freeze determination process described later.

The cathode gas supply unit 30 includes a cathode gas pipe 31, an air flow meter 32, a compressor 33, a first on-off valve 34, a pressure detection unit 35, a cathode off gas pipe 41, and a first regulator 42. The cathode gas pipe 31 is connected to the fuel cell stack 10 and supplies air taken in from the outside to the fuel cell stack 10.

The air flow meter 32 is provided in the cathode gas pipe 31 and measures the flow rate of the taken-in air. The compressor 33 compresses the air taken in from the outside in response to the control signal from the control unit 20, and supplies the air as cathode gas to the fuel cell stack 10. The first on-off valve 34 is provided between the compressor 33 and the fuel cell stack 10. The pressure detection unit 35 measures the pressure on the inlet side of the cathode gas of the fuel cell stack 10 and transmits it to the control unit 20.

The cathode off gas pipe 41 discharges the cathode off gas discharged from the fuel cell stack 10 to the outside of the fuel cell system 100. The first regulator 42 adjusts the pressure at the cathode gas outlet of the fuel cell stack 10 in response to the control signal from the control unit 20.

The anode gas supply unit 50 includes an anode gas pipe 51, an anode gas tank 52, a second on-off valve 53, a second regulator 54, an injector 55, a pressure detection unit 56, an anode off-gas pipe 61, and gas-liquid separation. A vessel 62, an exhaust / drain valve 63, a circulation pipe 64, and an anode gas pump 65 are provided. In the following, the anode gas pipe 51 downstream from the injector 55, the anode gas flow path in the fuel cell stack 10, the anode off-gas pipe 61, the gas-liquid separator 62, the circulation pipe 64, and the anode gas pump 65. The flow path composed of the above is also referred to as a circulation flow path 66. The circulation flow path 66 is a flow path for circulating the anode off gas of the fuel cell stack 10 to the fuel cell stack 10.

The anode gas tank 52 is connected to the anode gas inlet of the fuel cell stack 10 via the anode gas pipe 51, and supplies the anode gas to the fuel cell stack 10. The second on-off valve 53, the second regulator 54, the injector 55, and the pressure detection unit 56 are provided in the anode gas pipe 51 in this order from the upstream side, that is, from the side closer to the anode gas tank 52.

The second on-off valve 53 opens and closes in response to a control signal from the control unit 20. When the fuel cell system 100 is stopped, the second on-off valve 53 is closed. The second regulator 54 adjusts the pressure of the anode gas on the upstream side of the injector 55 in response to the control signal from the control unit 20. The injector 55 is an electromagnetically driven on-off valve in which the valve body is electromagnetically driven according to the drive cycle and valve opening time set by the control unit 20. The control unit 20 controls the flow rate of the anode gas supplied to the fuel cell stack 10 by controlling the drive cycle and the valve opening time of the injector 55. The pressure detection unit 56 measures the pressure on the anode gas inlet side of the fuel cell stack 10 and transmits it to the control unit 20. Both the pressure measured by the pressure detection unit 35 and the pressure measured by the pressure detection unit 56 are referred to as reaction gas pressures.

The anode off-gas pipe 61 is a pipe that connects the anode gas outlet of the fuel cell stack 10 and the gas-liquid separator 62. The anode off-gas pipe 61 guides the anode-off gas containing hydrogen gas, nitrogen gas, etc., which has not been used in the power generation reaction, to the gas-liquid separator 62.

The gas-liquid separator 62 is connected between the anode off-gas pipe 61 of the circulation flow path 66 and the circulation pipe 64. The gas-liquid separator 62 separates water as an impurity from the anode off-gas in the circulation flow path 66 and stores it.

The exhaust drain valve 63 is provided in the lower part of the gas-liquid separator 62. The exhaust drain valve 63 drains the water stored in the gas-liquid separator 62 and exhausts unnecessary gas (mainly nitrogen gas) in the gas-liquid separator 62. During the operation of the fuel cell system 100, the exhaust / drain valve 63 is normally closed and opens / closes in response to a control signal from the control unit 20. In the present embodiment, the exhaust drain valve 63 is connected to the cathode off gas pipe 41, and the water discharged by the exhaust drain valve 63 and unnecessary gas are discharged to the outside through the cathode off gas pipe 41.

The circulation pipe 64 is connected to a portion of the anode gas pipe 51 downstream of the injector 55. The circulation pipe 64 is provided with an anode gas pump 65 driven in response to a control signal from the control unit 20. The anode off gas from which water has been separated by the gas-liquid separator 62 is sent out to the anode gas pipe 51 by the anode gas pump 65. In the fuel cell system 100, the anode off gas containing hydrogen is circulated and supplied to the fuel cell stack 10 again to improve the utilization efficiency of the anode gas.

In the present embodiment, the whole of the above-mentioned cathode gas supply unit 30, the flow path through which the cathode gas in the fuel cell stack 10 flows, and the cathode off gas pipe 41 is referred to as a “cathode gas flow path”. Further, the entire anode gas supply unit 50, the flow path through which the anode gas in the fuel cell stack 10 flows, the anode off-gas pipe 61, and the circulation flow path 66 are referred to as an "anode gas flow path". When it is not necessary to distinguish between the cathode gas flow path and the anode gas flow path, these are referred to as "reaction gas flow paths".

The cooling medium circulation unit 70 adjusts the temperature of the fuel cell stack 10 by circulating the cooling medium through the fuel cell stack 10. The cooling medium circulation unit 70 includes a refrigerant supply pipe 71, a refrigerant discharge pipe 72, a radiator 73, a refrigerant pump 74, a three-way valve 75, a bypass pipe 76, and a temperature measuring unit 77. As the refrigerant, for example, water, antifreeze water such as ethylene glycol, air and the like are used.

The refrigerant supply pipe 71 is connected to the cooling medium inlet in the fuel cell stack 10, and the refrigerant discharge pipe 72 is connected to the cooling medium outlet of the fuel cell stack 10. The radiator 73 is connected to the refrigerant discharge pipe 72 and the refrigerant supply pipe 71, and cools the cooling medium flowing in from the refrigerant discharge pipe 72 by blowing air from an electric fan or the like, and then discharges the cooling medium to the refrigerant supply pipe 71. The refrigerant pump 74 is provided in the refrigerant supply pipe 71, and pumps the refrigerant to the fuel cell stack 10. The three-way valve 75 regulates the flow rate of the refrigerant to the radiator 73 and the bypass pipe 76. The temperature measuring unit 77 is connected to the refrigerant discharge pipe 72 and measures the temperature of the cooling water discharged from the fuel cell stack 10. The temperature measured by the temperature measuring unit 77 is substantially equal to the stack temperature of the fuel cell stack 10. Therefore, the temperature measuring unit 77 corresponds to the temperature measuring unit that acquires the stack temperature of the fuel cell stack 10.

The DC / DC converter 80 boosts the output voltage of the fuel cell stack 10 and supplies it to the PCU 81. The PCU 81 has a built-in inverter, and supplies electric power to the load 82 via the inverter according to the control of the control unit 20. Further, the PCU 81 limits the current of the fuel cell stack 10 by the control of the control unit 20.

The cell monitor 83 detects the cell voltage of the single cell 11. In the present embodiment, the cell monitor 83 detects the cell voltage of each single cell 11. The cell monitor 83 is connected to a cell group in which each single cell 11 of the fuel cell stack 10 is a set of n sheets (n is an integer of 1 or more), and the total value of the voltage of the single cell 11 for each cell group. May be measured by dividing by the number n of single cells constituting the cell group. The cell monitor 83 transmits the detected cell voltage to the control unit 20.

The electric power of the fuel cell stack 10 is supplied to a load 82 such as a traction motor (not shown) for driving wheels (not shown) via a power supply circuit including a PCU 81, a compressor 33 described above, an anode gas pump 65, and the above-mentioned electric power. It is supplied to various valves.

FIG. 2 is a plan view of the single cell 11 in which the inside of the cell is frozen. The single cell 11 includes a gas inlet manifold 12a, a gas outlet manifold 12b, a gas flow path 13, and a membrane electrode assembly 14. In the present embodiment, the manifolds 12a and 12b and the gas flow path 13 are collectively referred to as a "reaction gas flow path in the single cell 11". The manifolds 12a and 12b are formed on the peripheral edge of the single cell 11. A frozen portion FA in which the generated water is frozen is formed in the gas flow path 13 in the vicinity of the gas outlet manifold 12b.

The single cell 11 allows the reaction gas to flow from the gas inlet manifold 12a to the membrane electrode assembly 14 through the gas flow path 13, and is discharged from the gas outlet manifold 12b. When the fuel cell system 100 is started when the stack temperature is below the freezing point, the supply flow rate of the reaction gas (hereinafter referred to as “reaction gas flow rate”) is reduced by the warm-up operation, so that the gas flow path 13 on the gas inlet manifold 12a side is reduced. In the gas flow path 13 on the gas outlet manifold 12b side, the amount of gas is small, so that the amount of power generation is small. Therefore, in the gas flow path 13 on the gas outlet manifold 12b side, it is difficult to raise the temperature in the gas flow path 13 on the gas inlet manifold 12a side, and the temperature is low, so that the generated water tends to freeze.

FIG. 3 is a flowchart showing an example of the procedure of the freeze determination process in the present embodiment. Here, a cathode gas will be described as an example as the reaction gas. This process is started when the fuel cell system 100 is started when the stack temperature is below the freezing point, and is performed in parallel with the warm-up operation. When the warm-up operation is started, the control unit 20 starts the freeze determination process shown in FIG.

In step S100, the control unit 20 acquires the reaction gas pressure Pg and determines whether or not the reaction gas pressure Pg is higher than the predetermined threshold pressure Pth. The threshold pressure Pth is a pressure for determining whether or not the generated water is frozen in the single cell 11 or in the first regulator 42, and can be experimentally determined in advance. When the reaction gas pressure Pg is equal to or less than the threshold pressure Pth, the control unit 20 returns to the process of step S100. That is, step S100 is repeated until the reaction gas pressure Pg exceeds the threshold pressure Pth. When the predetermined time has elapsed or the warm-up operation is completed, it may be determined that the inside of the fuel cell system 100 is not frozen, and the freeze determination process may be terminated. On the other hand, when the reaction gas pressure Pg is higher than the threshold pressure Pth, the control unit 20 proceeds to step S110.

Subsequently, the control unit 20 acquires the cell voltage Vfc of the single cell 11 arranged at the end of the fuel cell stack 10 on the reaction gas discharge side in step S110, and the cell voltage Vfc is lower than the predetermined threshold voltage Vm. Is determined. In the present embodiment, the “end on the reaction gas discharge side” means the end on the side where the reaction gas is discharged from both ends of the single cell 11 of the fuel cell stack 10 in the stacking direction. As the "cell voltage of the single cell 11 arranged at the end on the reaction gas discharge side", the cell voltage of the single cell 11 on one plate can be used. Generally, in the stacking direction of the fuel cell stack 10 having m single cells (m is an integer of 2 or more), the cell voltage of the single cell 11 m / 2nd or less from the end can be used. The threshold voltage Vm is a pressure for determining whether or not the reaction gas flow path in the single cell 11 is frozen, and can be experimentally determined in advance. When the cell voltage Vfc is lower than the threshold voltage Vm, the control unit 20 proceeds to step S120 and determines that the gas flow path in the single cell 11 is frozen. On the other hand, when the cell voltage Vfc is equal to or higher than the threshold voltage Vm, the control unit 20 ends the freeze determination process. That is, it is determined that the gas flow path in the single cell 11 is not frozen. When it is determined that the gas flow path in the single cell 11 is not frozen, freezing occurs in another part of the reaction gas flow path (for example, one of the auxiliary equipment parts in the reaction gas flow path). You may judge that it is.

In the procedure of FIG. 3 described above, the determination of step S110 is performed using the cell voltage Vfc of the single cell 11 arranged at the end of the fuel cell stack 10, but instead, the step is performed using the average cell voltage. The determination of S110 may be made. As the average cell voltage, for example, a value measured by dividing the total value of k cell voltages (k is an integer of m / 2 or less) from the end on the reaction gas discharge side by k can be used. Further, the determination in step S110 may be performed using only the lowest cell voltage among the cell voltages of the k single cells 11 arranged at the end of the fuel cell stack 10.

FIG. 4 is a timing chart showing an example of the relationship between the stack temperature Ts, the reaction gas pressure Pg, and the reaction gas flow rate Qg when the gas flow path in the single cell 11 is not frozen. The upper graph shows the change in the stack temperature Ts, the middle graph shows the change in the reaction gas pressure Pg, and the lower graph shows the change in the reaction gas flow rate Qg.

As shown in the upper graph of FIG. 4, the stack temperature Ts gradually rises due to the warm-up operation. Further, as shown in the middle graph, the reaction gas pressure Pg is equal to the atmospheric pressure P0 at the time of starting, and gradually increases when the reaction gas is supplied after the start. However, when the generated water is not frozen in the reaction gas flow path, the reaction gas pressure Pg does not increase to the threshold pressure Pth.

FIG. 5 is a diagram showing the relationship between the cell number and the cell voltage Vfc when the gas flow path in the single cell 11 is not frozen. The upper side is a graph showing the relationship between the cell number and the cell voltage Vfc, and the lower side is a cross-sectional view of the fuel cell stack 10. In the upper graph, the vertical axis is the cell voltage Vfc and the horizontal axis is the cell number. The cell numbers are assigned one by one in order from the single cell 11 called the end "other end 10b" on the reaction gas discharge side of the fuel cell stack 10.

As shown in the upper graph of FIG. 5, since the reaction gas is supplied from the one end 10a side to the other end 10b side in the stacking direction of the single cell 11, the single cell 11 on the one end 10a side generates a large amount of reaction gas. However, since the single cell 11 on the other end 10b side has a small amount of reaction gas and it is difficult to generate electricity, the cell voltage Vfc of the single cell 11 on the other end 10b side is lower than the cell voltage Vfc of the single cell 11 on the one end 10a side. .. However, the cell voltage Vfc of the single cell 11 on the other end 10b side is also set to be equal to or higher than the threshold voltage Vm in step S110 of FIG.

FIG. 6 is a timing chart showing an example of the relationship between the stack temperature Ts, the reaction gas pressure Pg, and the reaction gas flow rate Qg when the gas flow path in the single cell 11 is frozen.

As shown in the upper graph of FIG. 6, the stack temperature Ts gradually rises due to the warm-up operation, but when the gas flow path in the single cell 11 is frozen, it does not rise above a certain temperature. .. Further, as shown in the graph in the middle stage, when the gas flow path in the cell is frozen, gas is accumulated in the cell or in the cathode gas pipe 31, and the reaction gas pressure Pg rises considerably. Along with this, as shown in the lower graph, the reaction gas flow rate Qg decreases as compared with FIG.

FIG. 7 is a diagram showing the relationship between the cell number and the cell voltage Vfc when the gas flow path in the single cell 11 is frozen. Since the reaction gas is supplied from one end 10a side to the other end 10b side in the stacking direction of the single cell 11, the single cell 11 on the one end 10a side has a large amount of reaction gas and tends to raise the temperature by power generation, but the other end 10b side. Since the single cell 11 has a small amount of reaction gas and a small amount of power generation, it is difficult to raise the temperature. Therefore, as shown in FIG. 7, a frozen portion FA (FIG. 2) in which the generated water is frozen is likely to be formed in the gas flow path in the single cell 11 on the other end 10b side of the fuel cell stack 10.

As shown in the upper graph of FIG. 7, the cell voltage Vfc of the single cell 11 in which the gas flow path in the single cell 11 is frozen becomes out of gas because the gas flow path 13 is blocked by freezing, and the single cell 11 The gas flow path inside becomes lower than the cell voltage Vfc of the single cell 11 which is not frozen, and becomes less than the threshold voltage Vm in step S110 of FIG.

FIG. 8 is a flowchart showing an example of the procedure for freezing treatment in the present embodiment. This process is performed when it is determined by the freeze determination process that the reaction gas flow path in the single cell 11 is frozen. When the control unit 20 starts this process, the reaction gas flow rate is increased in step S200.

Next, the control unit 20 acquires the reaction gas pressure Pg in step S210, and determines whether or not the reaction gas pressure Pg has dropped to a predetermined target pressure Pm or less. The target pressure Pm is a pressure for determining whether or not the gas flow path in the single cell blocked by freezing has been thawed, and can be experimentally determined in advance. When the reaction gas pressure Pg is equal to or less than the target pressure Pm, the control unit 20 proceeds to step S250 and returns the reaction gas flow rate increased in step S200 to the normal flow rate. On the other hand, when the reaction gas pressure Pg is larger than the target pressure Pm, the control unit 20 proceeds to step S220 to increase the calorific value of the single cell 11. In this embodiment, for example, the gas flow rate is further increased.

Subsequently, the control unit 20 acquires the reaction gas pressure Pg in step S230, and determines whether or not the reaction gas pressure Pg has dropped to a predetermined target pressure Pm or less. When the reaction gas pressure Pg is larger than the target pressure Pm, the control unit 20 returns to the process of step S230. That is, step S230 is repeated until the reaction gas pressure Pg falls below the target pressure Pm. On the other hand, when the reaction gas pressure Pg is equal to or less than the target pressure Pm, the control unit 20 proceeds to step S240 and returns the calorific value of the single cell 11 increased in step S220 to the normal calorific value. In the present embodiment, for example, the gas flow rate is returned to the flow rate set in step S200. Finally, the control unit 20 returns the reaction gas flow rate to the normal flow rate in step S250.

According to the fuel cell system 100 of the present embodiment described above, the control unit 20 uses the reaction gas pressure Pg on the inlet side and the cell voltage Vfc of the single cell 11 arranged on the other end 10b side of the single cell 11. Determine if the gas flow path inside is frozen. Since freezing of the generated water is likely to occur in the single cell 11 on the other end 10b side, it is possible to reliably determine the blockage due to freezing of the reaction gas flow path in the single cell 11.

B. Other embodiments:
In the above embodiment, the control unit 20 performs a freeze determination process using the cathode gas as a reaction gas. Instead, the control unit 20 may perform the freeze determination process using the anode gas as the reaction gas. Further, a freeze determination process may be performed on each of the cathode gas flow path and the anode gas flow path. However, it is preferable to use different values for the threshold pressure Pth between the cathode gas and the anode gas.

The present invention is not limited to the above-described embodiment, and can be realized with various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each embodiment described in the column of the outline of the invention are for solving the above-mentioned problems or for achieving a part or all of the above-mentioned effects. In addition, it is possible to replace or combine them as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 ... Fuel cell stack 10a ... One end 10b ... The other end 11 ... Single cell 12a ... Gas inlet manifold 12b ... Gas outlet manifold 13 ... Gas flow path 14 ... Membrane electrode assembly 20 ... Control unit 21 ... ECU
30 ... cathode gas supply unit 31 ... cathode gas piping 32 ... air flow meter 33 ... compressor 34 ... first on-off valve 35 ... pressure detection unit 41 ... cathode off gas piping 42 ... first regulator 50 ... anode gas supply unit 51 ... anode gas piping 52 ... Anodic gas tank 53 ... Second on-off valve 54 ... Second regulator 55 ... Injector 56 ... Pressure detector 61 ... Anodic off-gas pipe 62 ... Gas-liquid separator 63 ... Exhaust drain valve 64 ... Circulation pipe 65 ... Anodic gas pump 66 ... Circulation Flow path 70 ... Cooling medium circulation part 71 ... Refrigerator supply pipe 72 ... Refrigerator discharge pipe 73 ... Radiator 74 ... Refrigerator pump 75 ... Three-way valve 76 ... Bypass pipe 77 ... Temperature measurement unit 80 ... DC / DC converter 81 ... PCU
82 ... Load 83 ... Cell monitor 100 ... Fuel cell system FA ... Freezing part

Claims (1)

It ’s a fuel cell system.
With a fuel cell stack with multiple single cells,
A cell monitor that detects the cell voltage of the single cell, and
A temperature measuring unit that acquires the stack temperature of the fuel cell stack, and
A reaction gas flow path in which the reaction gas is supplied from one end side to the other end side in the stacking direction of the single cell, and
A pressure detection unit that detects the reaction gas pressure on the inlet side of the fuel cell stack of the reaction gas flow path,
With a control unit,
The control unit starts the fuel cell system when the stack temperature is below freezing.
When the reaction gas pressure is equal to or higher than a predetermined threshold pressure and the cell voltage of the single cell arranged on the other end side of the fuel cell stack is lower than the predetermined threshold voltage. It was determined that the reaction gas flow path in the cell was blocked due to freezing, and it was determined.
When the reaction gas pressure is equal to or higher than the threshold pressure and the cell voltage of the single cell arranged on the other end side of the fuel cell stack is equal to or higher than the threshold voltage, the inside of the single cell is excluded. A fuel cell system that determines that other parts of the reaction gas flow path are blocked due to freezing .

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