JP2006294402A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology to enable to discharge water accumulated in a fuel cell. <P>SOLUTION: This is a fuel cell system which has a gas suction part 316 to suction gas in a first inner reaction gas flow passage 314 of a first fuel cell stack by utilizing kinetic energy of exhaust gas from a second inner reaction gas flow passage 324 of a second fuel cell stack 200. This has a first supply passage 310 and a second supply passage 320 connected to the respective inner reaction gas passages, is connected to at least one of the supply passages, and has flow control parts 312, 322 connected at least either of the supply passages to adjust a supply amount of at least either of the reaction gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell system.

  In a fuel cell, water (water vapor) is generated on the cathode side during power generation. If such water accumulates in the fuel cell, problems may occur. Accordingly, various efforts have been made to discharge the water accumulated in the fuel cell. For example, Patent Document 1 proposes a method of circulating off gas from a fuel cell using a circulation path having a gas-liquid separator and removing moisture contained in the off gas.

Japanese Patent Laid-Open No. 2004-22198 JP 2004-87244 A JP 2004-146242 A JP 2003-308858 A JP 2001-185179 A

  However, in the past, the actual situation is that sufficient measures have not been taken regarding the discharge of water accumulated in the fuel cell. Such a problem is not limited to the cathode side but is common to the anode side.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a technique capable of discharging water accumulated in a fuel cell.

  In order to solve at least a part of the above problems, a fuel cell system according to the present invention includes a first fuel cell stack having a first internal reaction gas flow path and a second fuel cell stack having a second internal reaction gas flow path. And a gas suction part for sucking the gas in the first internal reaction gas flow path by using the kinetic energy of the exhaust gas from the second internal reaction gas flow path.

  According to this configuration, since the gas suction unit sucks the gas in the first fuel cell stack by using the kinetic energy of the exhaust gas of the second fuel cell stack, the water accumulated in the fuel cell can be discharged. It becomes possible.

  The fuel cell system further includes a first supply path that is a predetermined reaction gas supply path connected to the first internal reaction gas flow path, and the reaction gas connected to the second internal reaction gas flow path. A second supply path, which is a supply path, and at least one of the first supply path and the second supply path, and the first internal reaction gas flow path and the second internal reaction gas flow path, A supply amount adjustment unit that adjusts the supply amount of the reaction gas to at least one of the above, and a control unit that controls the operation of each unit, the control unit as the control mode of the supply amount adjustment unit, The supply amount adjustment is performed so that a supply amount ratio, which is a ratio of the reaction gas supply amount to the second internal reaction gas channel with respect to the reaction gas supply amount to the first internal reaction gas channel, is a relatively small value. A standard mode for controlling the unit, and A discharge mode for controlling the supply amount adjustment unit so that a supply rate ratio becomes a relatively large value, and further, by controlling the supply amount adjustment unit according to the discharge mode, the gas suction unit The gas in the first internal reaction gas channel may be sucked.

  According to this configuration, in the discharge mode, the ratio of the supply amount of the reaction gas to the second fuel cell stack with respect to the supply amount of the reaction gas to the first fuel cell stack can be increased compared to the standard mode. Therefore, the ratio of the kinetic energy of the exhaust gas of the second fuel cell stack that can be used by the gas suction unit to the amount of exhaust gas of the first fuel cell stack discharged by the first gas flow path can be increased. As a result, in the discharge mode, the first fuel cell stack is decompressed more strongly than in the standard mode, so that the water accumulated in the fuel cell can be discharged efficiently.

  The fuel cell system further includes a reaction gas supply unit that is connected to the first supply path and the second supply path and supplies the reaction gas to each of the supply paths, and the supply amount adjustment unit includes: The valve may be connected to at least one of the first supply path and the second supply path, and may include an adjustment valve capable of adjusting the flow rate of the reaction gas in the supply path to which the valve is connected. .

  According to this configuration, the supply amount ratio can be easily adjusted by controlling the adjustment valve.

  In the fuel cell system, the supply amount adjustment unit is provided in the first supply path as the adjustment valve, and is capable of adjusting the supply amount of the reaction gas to the first internal reaction gas flow path. The control unit sets the opening of the supply amount adjustment valve to a relatively large value in the standard mode, and sets the opening of the supply amount adjustment valve to a relatively small value in the discharge mode. It may be set.

  Further, in the fuel cell system, the supply amount adjusting unit is provided in the second supply path as the adjustment valve, and is capable of adjusting the supply amount of the reaction gas to the second internal reaction gas flow path. An adjustment valve, and the control unit sets the opening of the supply amount adjustment valve to a relatively small value in the standard mode, and sets the opening of the supply amount adjustment valve to a relatively large value in the discharge mode. It may be set to a value.

  Each of the fuel cell systems further includes a failure determination unit that determines whether or not there is a possibility of failure due to accumulation of water in the first internal reaction gas flow path, and the control unit may be defective by the failure determination unit. When it is determined that there is a property, the supply amount adjustment unit is controlled according to the discharge mode, and when it is determined by the failure determination unit that there is no possibility of a failure, the supply mode is adjusted according to the standard mode. The supply amount adjusting unit may be controlled.

  According to this configuration, when it is determined that there is a possibility of malfunction due to accumulation of water, the supply amount adjustment unit is controlled according to the discharge mode, so that the water accumulated in the fuel cell can be appropriately discharged. Is possible.

  The fuel cell system further includes a humidity sensor that measures the humidity of the exhaust gas from the first internal reaction gas flow path, and the failure determination unit has a humidity measured by the humidity sensor equal to or higher than a humidity threshold value. In such a case, it may be determined that there is a possibility of malfunction.

  According to this configuration, based on the humidity of the exhaust gas from the first fuel cell stack, it is possible to appropriately determine the presence or absence of a malfunction due to water accumulation.

  In the fuel cell system, the first fuel cell stack includes a plurality of single cells, the fuel cell system further includes a voltage sensor that measures a voltage of each single cell, and the failure determination unit includes The determination may be performed based on the voltage of each single cell.

  According to this configuration, it is possible to reflect the state of each single cell in the determination result of the possibility of malfunction.

  The fuel cell system further includes a power sensor that measures generated power including at least the power of the first fuel cell, and the failure determination unit calculates integrated power that is an integrated value of the generated power, and Each time the accumulated power increases by a predetermined reference accumulated power, it is determined that there is a possibility of a malfunction, and the control unit determines that there is a possibility of a malfunction every time the malfunction determination section determines that there is a malfunction. A series of processes including a discharge process for controlling the supply amount adjusting unit according to the above and a standard process for controlling the supply amount adjusting unit according to the standard mode after the discharge process may be executed.

  According to this configuration, it is possible to appropriately determine whether or not there is a possibility of malfunction based on the integrated power, and to appropriately discharge the water accumulated in the fuel cell.

  The fuel cell system may further include a temperature sensor that measures an operating temperature that reflects the temperature of the first internal reaction gas flow path, and the failure determination unit may be configured such that the operating temperature is equal to or lower than a temperature threshold value. It may be determined that there is a possibility of a malfunction.

  According to this configuration, it is possible to appropriately determine whether or not there is a possibility of malfunction due to accumulation of water based on the operating temperature.

  Each of the fuel cell systems further includes a first exhaust gas flow channel connected to the first internal reaction gas flow channel, and a second exhaust gas flow channel connected to the second internal reaction gas flow channel, The gas suction unit includes a first turbine provided in the first exhaust gas flow path, and a second turbine mechanically connected to the first turbine and provided in the second exhaust gas flow path. The first turbine and the second turbine are configured so that the exhaust gas from the second internal reaction gas flow channel that flows through the second exhaust gas flow channel drives the second turbine so that the second turbine is While driving a 1st turbine, it is good also as a said 1st turbine being comprised so that the gas in a said 1st internal reaction gas flow path may be attracted | sucked.

  Each of the fuel cell systems further includes a first exhaust gas flow channel connected to the first internal reaction gas flow channel, and a second exhaust gas flow channel connected to the second internal reaction gas flow channel. And the gas suction part includes an ejector that is provided in the second exhaust gas flow path and communicates with the first exhaust gas flow path, and the ejector flows through the second exhaust gas flow path. By using the flow of the exhaust gas from the flow path, the gas in the first internal reaction gas flow path may be sucked through the first exhaust gas flow path.

  The fuel cell system further includes a first exhaust gas flow channel connected to the first internal reaction gas flow channel, a second exhaust gas flow channel connected to the second internal reaction gas flow channel, and a predetermined exhaust gas flow channel. A reaction gas supply unit that supplies a reaction gas, a first supply channel that connects the reaction gas supply unit and the first internal reaction gas channel and supplies the reaction gas to the first internal reaction gas channel And a second supply path that connects the reaction gas supply section and the second internal reaction gas flow path and supplies the reaction gas to the second internal reaction gas flow path, and the gas suction section Comprises a first turbine provided in the first exhaust gas flow path, and a second turbine mechanically connected to the first turbine and provided in the second exhaust gas flow path, One turbine and the second turbine are (A) The flow rate ratio, which is the ratio of the flow rate of the exhaust gas from the second internal reaction gas channel flowing through the second exhaust gas channel to the flow rate of the exhaust gas from the first internal reaction gas channel flowing through the first exhaust gas channel, is If relatively large, exhaust gas from the second internal reaction gas flow channel that flows through the second exhaust gas flow channel drives the second turbine so that the second turbine drives the first turbine. The first turbine sucks the gas in the first internal reaction gas flow path, and (B) when the flow rate ratio is relatively small, the first internal reaction gas flow flowing in the first exhaust gas flow path. When the exhaust gas from the road drives the first turbine, the first turbine drives the second turbine, and the second turbine sucks the gas in the second internal reaction gas flow path. Sea urchin, may be configured.

  According to this configuration, the accumulated water can be discharged from the fuel cell in which the flow rate of the exhaust gas has decreased due to the accumulation of water.

  The present invention can be realized in various forms. For example, a fuel cell system, a control method or apparatus for the fuel cell system, a computer program for realizing the functions of these methods or apparatuses, and the computer The present invention can be realized in the form of a recording medium in which the program is recorded, a data signal that includes the computer program and embodied in a carrier wave, a vehicle in which the fuel cell system is mounted as a driving power source, and the like.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
B. Second embodiment:
C. Third embodiment:
D. Fourth embodiment:
E. Variation:

A. First embodiment:
FIG. 1 is a block diagram showing a configuration of a fuel cell system 900 as an embodiment of the present invention. The fuel cell system 900 includes fuel cell stacks 100 and 200, an air compressor 300, turbines 316 and 326, voltage sensors 130 and 230, temperature sensors 132 and 232, humidity sensors 134 and 234, and a controller 500. And. In FIG. 1, the gas flow path on the anode (also referred to as hydrogen electrode) side is omitted.

  The first fuel cell stack 100 (hereinafter, also simply referred to as “first stack 100”) is a solid polymer electrolyte fuel cell having a stack structure in which a plurality of fuel cell cells (also referred to as “single cells”) not shown are stacked. It is. Each of the fuel cells (not shown) includes a first internal air passage 193 provided on the cathode side and a first internal hydrogen passage 194 provided on the anode side.

  The second fuel cell stack 200 (hereinafter also simply referred to as “second stack 200”) has the same structure as the first stack 100. Each of the fuel cells (not shown) of the second stack 200 includes a second internal air channel 293 provided on the cathode side and a second internal hydrogen channel 294 provided on the anode side inside. I have.

  Oxidizing gas (for example, air) containing oxygen is supplied to each internal air flow path 193, 293. Each internal hydrogen flow path 194, 294 is supplied with a fuel gas containing hydrogen (for example, hydrogen gas). Each of the stacks 100 and 200 generates power by an electrochemical reaction between these oxygen and hydrogen. The electric power generated by the power generation is supplied to a load (not shown) connected to the stacks 100 and 200.

  The air compressor 300 supplies air as an oxidizing gas to the internal air flow paths 193 and 293. A main cathode gas supply path 302 is connected to the air compressor 300. The main cathode gas supply path 302 branches into a first branch cathode gas supply path 310 that reaches the first internal air flow path 193 and a second branch cathode gas supply path 320 that reaches the second internal air flow path 293. ing. A first cathode gas supply amount adjustment valve 312 is provided in the middle of the first branch cathode gas supply path 310, and a second cathode gas supply amount adjustment valve 322 is provided in the middle of the second branch cathode gas supply path 320. It has been.

  The upstream side of each first internal air flow path 193 of the first stack 100 is configured to merge and reach the first branch cathode gas supply path 310. The same applies to the upstream side of the second internal air flow path 293 of the second stack 200.

  A first cathode exhaust gas flow path 314 for exhausting air from the internal air flow path 193 is connected to the first stack 100. A first turbine 316 is provided in the middle of the first cathode exhaust gas flow path 314. On the other hand, a second cathode exhaust gas flow path 324 for exhausting from the internal air flow path 293 is connected to the second stack 200. A second turbine 326 is provided in the middle of the second cathode exhaust gas flow path 324. The first turbine 316 and the second turbine 326 are mechanically coupled.

  The first cathode exhaust gas flow path 314 is provided with a first humidity sensor 134 that measures the humidity of the exhaust gas. The second cathode exhaust gas flow path 324 is also provided with a second humidity sensor 234 that measures the humidity of the exhaust gas.

  The downstream side of each first internal air flow path 193 of the first stack 100 is configured to merge and reach the first cathode exhaust gas flow path 314. The same applies to the downstream side of the second internal air flow path 293 of the second stack 200.

  The first voltage sensor 130 is provided for each single cell of the first stack 100 and measures the voltage of the single cell (hereinafter also referred to as “cell voltage”). Similarly, the second voltage sensor 230 is provided for each single cell of the second stack 200 and measures the cell voltage. The first temperature sensor 132 measures the internal temperature of the first stack 100. Similarly, the second temperature sensor 232 measures the internal temperature of the second stack 200.

  Note that the temperature measured by the first temperature sensor 132 may be a temperature that reflects the temperature of the first internal air flow path 193. Therefore, the first temperature sensor 132 may directly measure the temperature inside the first stack 100, or may measure the temperature of cooling water (not shown) discharged from the first stack 100. . The same applies to the second temperature sensor 232.

  The controller 500 controls the overall operation state of the fuel cell system 900 by receiving a data signal from each component constituting the fuel cell system 900 and outputting a drive signal to each component. In particular, the control unit 500 has a function of controlling the opening amounts of the supply amount adjustment valves 312 and 322 based on the measurement results of the sensors 130, 132, 134, 230, 232, and 234 (details will be described later). ). The control unit 500 includes a CPU and a memory, and implements various functions by executing computer programs. Such a computer program can be supplied in a form recorded on a computer-readable recording medium. Note that part or all of the functions of the control unit 500 may be realized by hardware.

  FIG. 2 is a flowchart showing a procedure of opening degree control processing executed by the control unit 500 during the power generation operation of the fuel cell system 900. This opening degree control process is executed after the fuel cell system 900 is started.

  In step S100, the controller 500 sets the opening degree of each supply amount adjustment valve 312, 322 according to the normal mode. In the first embodiment, in the normal mode, the opening amounts of the supply amount adjusting valves 312 and 322 are set to predetermined values (for example, fully open). In the normal mode, the control unit 500 sets the drive amount (air supply amount) of the air compressor 300 so as to increase as the load increases. As a result, the amount of air supplied to each internal air flow path 193, 293 increases as the load size increases.

  As the “load magnitude”, various known values can be adopted. For example, the fuel cell system 900 may be provided with a load sensor (not shown) for measuring the power supplied to the load, and the measured value of this load sensor may be used.

  Incidentally, the exhaust gas from the first internal air flow path 193 (FIG. 1) is supplied to the first turbine 316. The first turbine 316 is driven by the exhaust gas. On the other hand, the exhaust gas from the second internal air flow path 293 is supplied to the second turbine 326. The second turbine 326 is driven by this exhaust gas. Here, the first turbine 316 and the second turbine 326 are configured such that their rotations are in an equilibrium state in the normal mode. That is, in the normal mode, the force by which the first turbine 316 drives the second turbine 326 and the force by which the second turbine 326 drives the first turbine 316 are balanced.

  In the normal mode, the opening degree of each of the valves 312 and 322 may be a variable value. For example, the controller 500 may set the opening degree to a larger value as the load is larger. In any case, in the normal mode, it is preferable to set the configuration of the turbines 316 and 326 and the opening degree of the valves 312 and 322 so that the rotation of the turbines 316 and 326 is in an equilibrium state.

In the next step S110, the control unit 500 determines whether or not there is a possibility of malfunction due to accumulation of water in each internal air flow path 193, 293 (hereinafter also referred to as “defect determination”). In the first embodiment, the following condition is adopted as a condition for determining a defect (hereinafter also referred to as “defect condition”).
“Condition C1: Including a low-voltage single cell whose cell voltage is below the voltage threshold”
Specifically, the control unit 500 determines that there is a possibility of a malfunction in the fuel cell stack that satisfies the condition C1.

  If excessive water accumulates in the internal air flow paths 193 and 293, the supply of the reaction gas (air) is suppressed, so the cell voltage often decreases. Therefore, the control unit 500 can estimate that there is a possibility of malfunction when the cell voltage is equal to or lower than the voltage threshold value. Various values can be adopted as the voltage threshold value. For example, a statistical value (for example, average value −2 * standard deviation) calculated statistically using each cell voltage may be employed, a predetermined constant value may be employed, You may employ | adopt the predetermined value decided according to it. In either case, the format and value of the voltage threshold value may be determined in advance based on experiments.

  When it is determined that there is a possibility of malfunction, the controller 500 sets the opening of each of the supply amount adjustment valves 312 and 322 according to the discharge mode in the next step S120. In the discharge mode, the opening amount of the supply amount adjustment valve of the fuel cell stack (hereinafter referred to as “failure stack”) that may be defective is set to a value smaller than the opening amount in the normal mode. However, it is set to a value larger than that of the fully closed state so that power generation due to the defective stack does not stop. In the first embodiment, when the opening degree of one supply amount adjustment valve is set to a small value in the discharge mode, the opening degree of the other supply amount adjustment valve is not changed. Further, in the first embodiment, the control unit 500 maintains the driving amount (for example, the rotation speed) of the air compressor 300 in the discharge mode at the same value as the driving amount in the normal mode. However, it may be set to a value larger than the driving amount in the normal mode, or may be set to a small value.

  FIG. 3 is an explanatory diagram showing the operating state of the fuel cell system 900 in the discharge mode. FIG. 3 shows a case where the first stack 100 may be defective. The controller 500 sets the opening of the first cathode gas supply amount adjustment valve 312 to a small value. Then, compared with the normal mode, the ratio of the air supply amount to the second stack 200 with respect to the air supply amount to the first stack 100 is increased, and further, the second to the flow rate of the exhaust gas flowing through the first cathode exhaust gas flow path 314. The ratio of the flow rate of the exhaust gas flowing through the cathode exhaust gas flow path 324 also increases. Therefore, the ratio of the driving force generated by the second turbine 326 to the driving force generated by the first turbine 316 is larger than that in the normal mode. As a result, the first turbine 316 is driven by the second turbine 326 to suck the gas in the first internal air flow path 193 (step S130).

  Thus, since the suction force by the first turbine 316 with respect to the amount of air supplied to the first internal air flow path 193 becomes strong, the first internal air flow path 193 is decompressed more strongly than in the normal mode. Then, since the water accumulated in the first internal air flow path 193 is likely to evaporate, the water accumulated in the first internal air flow path 193 is discharged, and the problem can be solved. In particular, if excessive water accumulates in the first internal air flow path 193, it may be difficult to discharge water due to the gas flow. Even in such a case, since the evaporation of water is promoted in the discharge mode, the accumulated water can be discharged.

  The case where the first stack 100 is likely to be defective has been described above, but the control unit 500 performs the same control even when the second stack 200 is likely to be defective.

  Thereafter, the control unit 500 returns to step S110 to perform defect determination. Here, when the failure condition is not satisfied for any of the stacks 100 and 200, the normal mode (step S100) is executed. On the other hand, when the failure condition is satisfied for any one of the stacks 100 and 200, the discharge mode (steps S120 and S130) is executed. If there is a possibility of malfunction in both stacks 100 and 200, the opening of the supply amount adjustment valve is set according to the discharge mode one by one.

  As described above, in the first embodiment, the ratio of the air supply amount to the other fuel cell stack with respect to the air supply amount to the defective stack is larger in the discharge mode than in the normal mode. The internal air flow path can be depressurized more strongly than in the normal mode. As a result, it is possible to discharge the water accumulated in the defective stack.

  In the first embodiment, in the discharge mode, the amount of air supplied to the other fuel cell stack different from the defective stack is larger than that in the normal mode. Accordingly, it is possible to promote the discharge of water from the other fuel cell stack.

The malfunction condition is not limited to the condition C1 described above, and other various conditions can be employed. For example, the following conditions can be adopted.
“Condition C2: Cell voltage variation (deviation) is greater than a predetermined value”
“Condition C3: The power generation time has increased by a predetermined time”
“Condition C4: The accumulated power has increased by a predetermined reference accumulated power”

  In a normal fuel cell, as the power generation time increases and the integrated power (the integrated value of the generated power) increases, the possibility of malfunction due to accumulation of water increases. Therefore, it can be estimated that there is a possibility of malfunction when the amount of increase in power generation time or the amount of increase in integrated power is greater than or equal to a threshold value.

  When the condition C3 is adopted, a timer is provided in the control unit 500, and the control unit 500 may measure the power generation time. When the condition C4 is employed, a power sensor may be provided in each stack 100 and 200, and the control unit 500 may calculate an integrated value of power. Here, in order to perform defect determination for each stack, it is preferable to measure such power generation time and integrated power for each stack 100, 200. However, the power generation time common to both stacks 100 and 200 may be measured, or a power sensor that measures the total value of the generated power of both stacks 100 and 200 may be used. In this case, if the failure condition is satisfied, it may be estimated that both stacks 100 and 200 have a possibility of failure.

  Further, there are cases where it is difficult to confirm the resolution of the problem, as in the case where the conditions C3 and C4 are adopted. In such a case, the control unit 500 only needs to execute the discharge mode for a predetermined period of time each time the failure condition is satisfied, and then execute a series of processes for shifting to the normal mode. In this case, every time a series of processes is executed, the amount of increase in power generation time and the amount of increase in integrated power may be measured again from zero.

  Incidentally, the controller 500 may execute the opening degree control process based on the failure determination result when stopping the power generation. FIG. 4 is a flowchart showing an example of the procedure of the opening degree control process executed by the control unit 500 in the stop process of the fuel cell system 900.

  In step S200, the control unit 500 (FIG. 1) acquires the humidity of the exhaust gas of each stack 100, 200 from the humidity sensors 134, 234.

  In next step S210, control unit 500 (FIG. 1) determines whether or not each humidity is equal to or higher than a predetermined humidity threshold value. When excess water accumulates in the internal air flow paths 193 and 293, the humidity in the exhaust gas often increases. Therefore, it can be estimated that there is a possibility of malfunction when the humidity of the exhaust gas is equal to or higher than the humidity threshold. Note that the humidity threshold value may be determined in advance based on experiments.

  If it is determined that there is a possibility of malfunction, the controller 500 maintains the drive without stopping the air compressor 300 in the next step S215, and adjusts each supply amount according to the discharge mode in the next step S220. The opening degree of the valves 312 and 322 is set. At this time, power for driving the air compressor 300 may be generated in the other fuel cell stack different from the defective stack. Further, a secondary battery for driving the air compressor 300 may be provided in the fuel cell system 900, and power generation of both the fuel cell stacks 100 and 200 may be stopped.

  The processes in steps S220 and S230 are the same as steps S120 and S130 in FIG. As a result, the water accumulated in the internal air flow paths 193 and 293 can be discharged. Thereafter, the control unit 500 returns to step S200 again, and repeatedly executes the processing of steps S210 to S230 until the humidity of the exhaust gas of both stacks 100 and 200 becomes less than the humidity threshold value.

  On the other hand, when the humidity of the exhaust gas in any of the stacks 100 and 200 is less than the humidity threshold value, the control unit 500 stops the air compressor 300 and ends the opening degree control process. Thereafter, the process returns to a predetermined stop process, and the fuel cell system 900 is stopped.

  As described above, in the opening degree control process of FIG. 4, the control unit 500 can discharge water from the internal air flow paths 193 and 293 when power generation is stopped. Accordingly, it is possible to prevent power generation from being started by the accumulated water in the internal air flow paths 193 and 293 at the next startup. Moreover, even when the fuel cell system 900 after being stopped is placed at a low temperature, it is possible to prevent water from freezing in the internal air flow paths 193 and 293.

  In addition, when the control part 500 determines with the possibility of a malfunction, it is good also as performing discharge mode only for predetermined time, and complete | finishing an opening degree control process after that. Here, it is preferable to set the time for executing the discharge mode to a longer time as the humidity is higher. Further, the control unit 500 may set the air supply amount by the air compressor 300 in the discharge mode to a value larger than the supply amount in the normal mode.

  By the way, the control part 500 may perform the opening degree control process based on the defect determination result when starting power generation (at the time of activation). FIG. 5 is a flowchart showing an example of the procedure of the opening degree control process executed by the control unit 500 in the startup process of the fuel cell system 900.

  In step S300, the control unit 500 (FIG. 1) acquires the temperature of each stack 100, 200 from the temperature sensors 132, 232.

  In next step S310, control unit 500 (FIG. 1) determines whether or not each temperature is equal to or lower than a predetermined temperature threshold value. The lower the temperature of the stacks 100 and 200, the easier it is for water vapor to condense in the internal air flow paths 193 and 293, and as a result, water tends to accumulate in the internal air flow paths 193 and 293. Accordingly, the control unit 500 can estimate that there is a possibility of a malfunction when the temperature of the stacks 100 and 200 is equal to or lower than the temperature threshold value. Note that the temperature threshold value may be determined in advance based on experiments. In addition, when the temperature of the stacks 100 and 200 becomes 0 ° C. or less, the accumulated water may be frozen. Therefore, it is preferable to set the temperature threshold value to 0 ° C. or higher. On the other hand, it is preferable that the temperature threshold is low in order to increase the accuracy of defect determination. For example, a value within the range of 0 ° C. to + 10 ° C. can be used as the temperature threshold value.

  When it is determined that there is a possibility of malfunction, the controller 500 sets the opening degree of each of the supply amount adjustment valves 312 and 322 according to the discharge mode in the next step S320. The processes in steps S320 and S330 are the same as steps S120 and S130 in FIG. As a result, the water accumulated in the internal air flow paths 193 and 293 can be discharged. Thereafter, the control unit 500 returns to step S300 again, and repeatedly executes the processes of steps S310 to S330 until the temperature of both stacks 100 and 200 exceeds the temperature threshold.

  On the other hand, when the temperature of any of the stacks 100 and 200 exceeds the temperature threshold value, the control unit 500 ends the opening degree opening control process. Thereafter, the process returns to a predetermined activation process, and the fuel cell system 900 is activated. After startup, the normal mode is executed.

  As described above, in the opening degree control process of FIG. 5, the control unit 500 can discharge water from the internal air flow paths 193 and 293 at the start of power generation (at the time of startup). Accordingly, it is possible to suppress the inability to start power generation due to accumulation of water in each of the internal air flow paths 193 and 293 even during startup at low temperatures.

  Normally, since the two stacks 100 and 200 are installed in the same place (for example, inside the same vehicle), the temperature of both at the time of startup is often the same. In such a case, the control unit 500 executes the discharge mode by using one predetermined fuel cell stack as a suction target (hereinafter referred to as “target stack”) in step S320. This makes it possible to easily start the target stack. In particular, even when starting from below freezing point, water discharge is promoted in the target stack, and as a result, freezing of water is suppressed, so that the target stack can be easily started. That is, at least one of the two stacks 100 and 200 can be easily activated.

  Here, it is preferable that one fuel cell stack and the other fuel cell stack are configured to be able to exchange heat with each other. In this way, when one fuel cell stack starts power generation, the heat generated by the power generation can raise the temperature of the other fuel cell stack. As a result, even when starting from a low temperature state (particularly below freezing point), both stacks 100 and 200 can be started quickly.

  Note that various well-known configurations can be adopted as a configuration allowing heat exchange between the two fuel cell stacks. For example, a configuration in which two fuel cell stacks are brought into contact with each other may be employed. Moreover, you may employ | adopt the structure which circulates a cooling water between two fuel cell stacks.

B. Second embodiment:
FIG. 6 is a block diagram showing the configuration of the fuel cell system 900b in the second embodiment. FIG. 6 also shows the gas flow path on the anode side. The difference from the fuel cell system 900 shown in FIG. 1 is that each turbine 316 and 326 can suck the anode side in addition to the cathode side.

  The fuel cell system 900 b includes a hydrogen supply device 400. The hydrogen supply device 400 supplies hydrogen gas as a fuel gas to the internal hydrogen flow paths 194 and 294. As the configuration of the hydrogen supply apparatus 400, various known configurations can be employed. For example, a configuration having a hydrogen tank and a pressure regulating valve can be employed.

  A main anode gas supply path 402 is connected to the hydrogen supply device 400. The main anode gas supply path 402 branches into a first branch anode gas supply path 410 that reaches the first internal hydrogen flow path 194 and a second branch anode gas supply path 420 that reaches the second internal hydrogen flow path 294. ing. A first anode gas supply amount adjustment valve 412 is provided in the middle of the first branch anode gas supply path 410, and a second anode gas supply amount adjustment valve 422 is provided in the middle of the second branch anode gas supply path 420. It has been.

  The upstream side of each first internal hydrogen channel 194 of the first stack 100 is configured to merge and reach the first branch anode gas supply channel 410. The same applies to the upstream side of the second internal hydrogen flow path 294 of the second stack 200.

  Connected to the first stack 100 is a first anode exhaust gas passage 414 for exhausting from the first internal hydrogen passage 194. The first anode exhaust gas flow path 414 branches into a first anode suction path 432 leading to the first cathode exhaust gas flow path 314 and a first anode circulation path 434 toward the main anode gas supply path 402. A first three-way regulating valve 430 is provided at this branch point. The first anode circulation path 434 is connected to the main anode gas circulation path 404. The main anode gas circulation path 404 is connected to the main anode gas supply path 402.

  Similarly, a second anode exhaust gas flow path 424 for exhausting from the second internal hydrogen flow path 294 is connected to the second stack 200. The second anode exhaust gas flow path 424 is branched into a second anode suction path 442 leading to the second cathode exhaust gas flow path 324 and a second anode circulation path 444 toward the main anode gas supply path 402. A second three-way regulating valve 440 is provided at this branch point. The second anode circulation path 444 is connected to the main anode gas circulation path 404.

  The downstream side of each first internal hydrogen flow path 194 of the first stack 100 is configured to merge and reach the first anode exhaust gas flow path 414. The same applies to the downstream side of the second internal hydrogen flow path 294 of the second stack 200.

  In the second embodiment, the controller 500b switches between the normal mode and the discharge mode as in the first embodiment. In the normal mode, the first three-way regulating valve 430 is controlled so that the entire amount of exhaust gas from the first internal hydrogen flow path 194 flows to the first anode circulation path 434. The same applies to the second three-way regulating valve 440. As a result, in the normal mode, the exhaust gas from the internal hydrogen flow paths 194 and 294 is circulated again to the internal hydrogen flow paths 194 and 294. Here, a circulation device (for example, a pump or an ejector) for circulating gas may be provided in the main anode gas circulation path 404 or the main anode gas supply path 402.

  FIG. 7 is an explanatory diagram showing the operating state of the fuel cell system 900b in the discharge mode. FIG. 7 shows a case where there is a possibility that the first stack 100 is defective. There are two differences from the first embodiment shown in FIG. The first difference is that the controller 500b sets the opening of the first anode gas supply amount adjustment valve 412 to a value smaller than the opening in the normal mode. The second difference is that the control unit 500 b controls the first three-way regulating valve 430 so that the entire amount of exhaust gas from the first internal hydrogen flow path 194 flows to the first anode suction path 432. In addition, the opening setting of each valve (the second cathode gas supply amount adjustment valve 322, the second anode gas supply amount adjustment valve 422, the second three-way adjustment valve 440) on the second stack 200 side is set in the normal mode (during power generation operation) ).

  As a result, in the exhaust mode, the first turbine 316 sucks the first internal hydrogen flow path 194 in addition to the first internal air flow path 193. Therefore, in the second embodiment, not only the water accumulated in the first internal air flow path 193 but also the water accumulated in the first internal hydrogen flow path 194 can be discharged.

  As in the second embodiment, when the first turbine 316 sucks both the cathode-side internal flow path 193 and the anode-side internal flow path 194, the fuel gas is discharged. In order to suppress this, it is preferable to reduce the amount of fuel gas supplied to the anode-side internal flow path 194 to zero. Specifically, the opening degree of the first anode gas supply amount adjustment valve 412 may be set to fully closed. However, in this case, power generation in the target stack is stopped.

  In the embodiment shown in FIG. 6, a configuration is adopted in which the anode side internal flow paths 194, 294 of both stacks 100, 200 can be sucked, but only the anode side internal flow path of one stack is sucked. The resulting configuration may be employed. For example, the second three-way regulating valve 440 may be omitted, and the second anode exhaust gas flow path 424 may be directly connected to the main anode gas circulation path 404.

C. Third embodiment:
FIG. 8 is a block diagram showing a configuration of a fuel cell system 900c in the third embodiment. The only difference from the fuel cell system 900 shown in FIG. 1 is that an ejector 328 and an exhaust valve 318 are provided instead of the turbines 316 and 326.

  An exhaust valve 318 is provided in the first cathode exhaust gas flow path 314. Further, an ejector 328 is provided in the second cathode exhaust gas flow path 324. The ejector 328 is further connected between the stack 100 of the first cathode exhaust gas flow path 314 and the exhaust valve 318.

  The ejector 328 can suck the gas in the first cathode exhaust gas flow path 314, that is, the first internal air flow path 193 by using the flow of the exhaust gas flowing through the second cathode exhaust gas flow path 324. . As the configuration of such an ejector, various known configurations can be employed. For example, a configuration having a nozzle and a diffuser can be employed.

  In the third embodiment, the controller 500c switches between the normal mode and the discharge mode, as in the first embodiment. In the normal mode, the control unit 500c sets the opening degree of the exhaust valve 318 to an opening degree (for example, fully open) such that the exhaust gas from the first internal air flow path 193 flows through the exhaust valve 318.

  FIG. 9 is an explanatory diagram showing the operating state of the fuel cell system 900c in the discharge mode. The controller 500c sets the opening degree of the first cathode gas supply amount adjustment valve 312 to a value smaller than the opening degree in the normal mode, as in the first embodiment shown in FIG. Furthermore, the controller 500c sets the opening of the exhaust valve 318 to be fully closed. Then, since the ratio of the air supply amount to the second stack 200 with respect to the air supply amount to the first stack 100 becomes larger than in the normal mode, the ejector 328 sucks the gas in the first internal air flow path 193. Strength also increases. As a result, the first internal air flow path 193 is decompressed more strongly than in the normal mode. Then, since the water accumulated in the first internal air flow path 193 is easily evaporated, the water accumulated in the first internal air flow path 193 can be discharged.

  The opening degree of the exhaust valve 318 in the discharge mode is not limited to being fully closed, and various opening degrees that can prevent the ejector 328 from sucking external gas through the exhaust valve 318 can be employed. . However, an opening smaller than the normal mode is preferable. Further, when the suction force of the ejector 328 in the discharge mode is sufficiently strong, the exhaust valve 318 may be omitted. In the embodiment shown in FIG. 8, the ejector 328 is provided only in the second cathode exhaust gas passage 324, but an ejector may also be provided in the first cathode exhaust passage 314.

D. Fourth embodiment:
FIG. 10 is a block diagram showing a configuration of a fuel cell system 900d in the fourth embodiment. The difference from the fuel cell system 900 shown in FIG. 1 is that the cathode gas supply amount adjustment valves 312 and 322 are omitted. In the fourth embodiment, the control unit 500d does not perform an intentional adjustment process of the air supply amount balance for the internal air flow paths 193 and 293, unlike the above-described embodiments. However, when water accumulates in one internal air flow path of each of the stacks 100 and 200, the accumulated water is naturally sucked by the turbine.

  FIG. 11 is an explanatory diagram showing the operating state of the fuel cell system 900d when water accumulates in the first internal air flow path 193. As shown in FIG. In this case, since it becomes difficult for air to flow through the first internal air flow path 193, the amount of air flowing through the first internal air flow path 193 naturally decreases, and the amount of air flowing through the second internal air flow path 293 Will increase. Then, the ratio of the flow rate of the exhaust gas flowing through the second cathode exhaust gas channel 324 to the flow rate of the exhaust gas flowing through the first cathode exhaust gas channel 314 also increases. Therefore, the first turbine 316 is driven by the second turbine 326 to suck the gas in the first internal air flow path 193. As a result, the water accumulated in the first internal air flow path 193 is naturally discharged.

  When water is discharged from the first internal air flow path 193 in this way, the ease of air flow in the first internal air flow path 193 is restored, so the amount of air flowing through each internal air flow path 193, 294 is also restored. .

  The case where water accumulates in the first internal air flow path 193 has been described above, but the accumulated water is discharged naturally in the same manner when water accumulates in the second internal air flow path 293. Thus, in the fourth embodiment, even if water accumulates in the internal air flow path of one fuel cell stack, the accumulated water is naturally discharged.

E. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

Modification 1:
In each of the embodiments described above, the control units 500, 500b, and 500c (FIGS. 1, 6, and 8) have a function as the “defect determination unit” in the present invention. In the first, second, and fourth embodiments (FIGS. 1, 6, and 10), the first turbine 316 and the second turbine 326 as a whole correspond to the “gas suction portion” in the present invention. . In the third embodiment (FIG. 8), the ejector 328 corresponds to the “gas suction part” in the present invention. In addition, as a structure of a gas suction part, various structures different from these are employable. In general, it is possible to employ any configuration that sucks the gas in one fuel cell stack by using the kinetic energy of the exhaust gas of the other fuel cell stack. Here, it is preferable to employ a configuration in which the kinetic energy of the exhaust gas is used without being converted into another form (for example, electric energy or heat energy).

Modification 2:
In the first to third embodiments (FIGS. 1, 6, and 8), the opening amount setting mode of the supply amount adjusting valves 312 and 322 is not limited to the normal mode and the discharge mode described above, but various other modes. The mode can be adopted. However, it is preferable that the control units 500, 500b, and 500c have at least a discharge mode. Here, the discharge mode means an operation mode in which the opening of each valve 312 and 322 is set so that the gas suction unit sucks the gas in the internal air flow path of the target stack. Note that the opening degree of each of the valves 312 and 322 in the discharge mode may be determined in advance based on experiments.

Furthermore, in addition to the discharge mode, the control units 500, 500b, and 500c preferably have a normal mode in which the degree of pressure reduction by the gas suction unit is weaker than the discharge mode. As such a normal mode and a discharge mode, for example, a setting mode in which the following relationship R1 is established can be employed.
“Relationship R1: Loss factor ratio in emission mode is smaller than loss factor ratio in normal mode”
Here, the “loss factor ratio” means the ratio of the loss coefficient of the gas supply path connected to the other fuel cell stack to the loss coefficient of the gas supply path connected to the target stack. The “loss factor” means an index indicating the difficulty of gas flow in the flow path. As the loss coefficient, for example, a proportional constant can be used when it is assumed that the pressure loss of the gas flowing through the flow path is proportional to the square of the flow velocity of the gas flowing through the flow path. Such a loss factor can be obtained by experiment.

  Here, it is assumed that the above-described relationship R1 holds. When the control unit 500, 500b, 500c switches the operation mode from the discharge mode to the normal mode, the ratio of the gas supply amount to the other fuel cell stack with respect to the gas supply amount to the target stack becomes small. Then, the ratio of the kinetic energy of the exhaust gas of the other stack that can use the gas suction unit to the flow rate of the exhaust gas discharged from the target stack is also reduced. Therefore, the degree of decompression of the target stack in the normal mode is weaker than that in the discharge mode. As a result, it is possible to suppress the power generation efficiency in the target stack from being excessively reduced. Conversely, the water accumulated in the target stack can be discharged by switching the operation mode from the normal mode to the discharge mode.

  The opening settings of the supply amount adjustment valves 312 and 322 in the discharge mode when the normal mode is set as a reference are not limited to the settings where the opening amount of the supply amount adjustment valve on the target stack side is small. Can be adopted. For example, the opening degree of the supply amount adjustment valve on the target stack side may be reduced, and the opening degree of the supply amount adjustment valve on the other stack side may be further increased. Alternatively, the opening degree of the supply amount adjustment valve on the other stack side may be increased without changing the opening degree of the supply amount adjustment valve on the target stack side. In general, any opening setting that satisfies the above-described relation R1 can be employed.

  The loss coefficient adjusting unit is not limited to the gas supply amount adjusting valves 312 and 322, and any device capable of adjusting the loss coefficient of the gas flow path can be employed. For example, in the fuel cell system 900 of FIG. 1, a three-way valve may be provided at the junction of the main cathode gas supply path 302 and the two branched cathode gas supply paths 310 and 320. In this way, the ratio of the gas supply amount to each stack 100, 200 can be adjusted by controlling the three-way valve.

Modification 3:
In each of the embodiments described above, one air compressor 300 supplies the oxidizing gas to the two fuel cell stacks 100 and 200. Instead, independent air is supplied to each of the fuel cell stacks 100 and 200. It is good also as connecting a compressor. For example, in the fuel cell systems 900, 900b, and 900c (FIGS. 1, 6, and 8), each of the branched cathode gas supply paths 310 and 320 may be connected to different compressors. In this case, the control units 500, 500b, and 500c are also referred to as the other fuel cell stack side compressor (also referred to as the “other side compressor”) with respect to the air supply amount by the target stack side compressor (also referred to as the “target side compressor”). It is possible to discharge water from the target stack by increasing the ratio of the air supply amount by (). For example, the drive amount of the target side compressor may be controlled so that the supply amount by the target side compressor in the discharge mode becomes small when the normal mode is used as a reference (for example, the rotation speed is reduced). Further, the drive amount of the other side compressor may be controlled (for example, the rotation speed is increased) so that the supply amount by the other side compressor in the discharge mode is increased. Here, in the discharge mode, only the supply amount (drive amount) of one of the compressors may be changed, or the supply amount (drive amount) of both compressors may be changed. Note that the supply amount (drive amount) of each compressor in the normal mode is preferably set in advance so that the suction force by the gas suction unit is smaller than the suction force in the discharge mode.

  In addition, as a supply part which supplies oxidizing gas, not only an air compressor but a well-known various apparatus is employable.

Modification 4:
In each of the above-described embodiments, the gas suction unit sucks the cathode-side internal air flow path, but instead of this, only the anode-side internal hydrogen flow path may be sucked. However, in a normal fuel cell, the amount of water accumulated in the cathode tends to be larger than that in the anode, so it is preferable to suck at least the internal air flow path on the cathode side.

  In each of the above embodiments, the gas suction unit uses the exhaust gas in the internal air flow path, but instead, the exhaust gas in the internal hydrogen flow path may be used. However, the gas used for the suction is preferably the same gas as the gas to be sucked. In any case, it is preferable that the gas suction unit uses exhaust gas from the flow path through which the reaction gas for power generation inside the fuel cell stack flows. In this way, it is not necessary to separately provide a driving device (for example, a motor) for the gas suction unit.

  Further, in each of the above-described embodiments, the gas suction unit is configured to provide a gas in the internal reaction gas flow path (for example, the internal air flow path 193) via the exhaust gas flow path (for example, the first cathode exhaust gas flow path 314 in FIG. 1). However, the position at which the gas suction unit sucks the gas can be set to an arbitrary position communicating with the internal reaction gas flow path. For example, a configuration in which the gas suction unit sucks through a gas supply path (for example, the first branch cathode gas supply path 310) may be employed, or a structure in which suction is performed from the middle of the internal reaction gas flow path may be employed. Good. However, the amount of water accumulated in the internal reaction gas channel tends to increase toward the downstream side of the internal reaction gas channel. Therefore, if the configuration in which the gas suction unit sucks through the exhaust gas flow path is adopted, the water accumulated in the internal reaction gas flow path can be efficiently discharged.

Modification 5:
In the first to third embodiments, the method of determining the operation mode to be executed by the control units 500, 500b, and 500c is not limited to the method of switching the operation mode according to the failure determination result, and other various methods. Can be adopted. For example, the control units 500, 500b, and 500c may determine an operation mode to be executed according to a user instruction.

Modification 6:
In each of the above embodiments, two fuel cell stacks 100 and 200 are used, but three or more fuel cell stacks may be used. Also in this case, turbines mechanically connected to each other may be provided in the exhaust gas flow paths of the fuel cell stacks. In this way, it is possible to adjust the balance of the driving force generated by each turbine by adjusting the amount of gas supplied to each fuel cell stack. As a result, the turbine having a relatively small driving force can be sucked in the fuel cell stack by being driven by another turbine having a relatively large driving force.

Modification 7:
In each of the above embodiments, the fuel cell stacks 100 and 200 are not limited to solid polymer electrolyte fuel cells, but are solid oxide electrolyte types, phosphoric acid electrolyte types, alkaline aqueous electrolyte types, and molten carbonate electrolyte types. Various types of fuel cells can be employed.

The block diagram which shows the structure of the fuel cell system 900 as one Example of this invention. The flowchart which shows the procedure of the opening degree control process which the control part 500 performs during an electric power generation driving | operation. Explanatory drawing which shows the driving | running state of the fuel cell system 900 in discharge mode. The flowchart which shows an example of the procedure of the opening degree control process which the control part 500 performs in a stop process. The flowchart which shows an example of the procedure of the opening degree control process which the control part 500 performs in a starting process. The block diagram which shows the structure of the fuel cell system 900b in 2nd Example. Explanatory drawing which shows the driving | running state of the fuel cell system 900b in discharge mode. The block diagram which shows the structure of the fuel cell system 900c in 3rd Example. Explanatory drawing which shows the driving | running state of the fuel cell system 900c in discharge mode. The block diagram which shows the structure of the fuel cell system 900d in 4th Example. Explanatory drawing which shows the driving | running state of the fuel cell system 900d when water accumulate | stores in the 1st internal air flow path 193. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... 1st fuel cell stack 130 ... 1st voltage sensor 132 ... 1st temperature sensor 134 ... 1st humidity sensor 193 ... 1st internal air flow path 194 ... 1st inside Hydrogen flow path 200 ... second fuel cell stack 230 ... second voltage sensor 232 ... second temperature sensor 234 ... second humidity sensor 293 ... second internal air flow path 294 ... Second internal hydrogen flow path 300 ... Air compressor 302 ... Main cathode gas supply path 310 ... First branch cathode gas supply path 312 ... First cathode gas supply amount adjustment valve 314 ... First Cathode exhaust gas flow path 316 ... first turbine 318 ... exhaust valve 320 ... second branch cathode gas supply path 322 ... second cathode gas supply amount adjustment valve 324 ... second cathode exhaust gas flow path 326 ... Second turbine 328 ... Ejector 400 ... Hydrogen supply device 402 ... In-anode gas supply path 404 ... Main anode gas circulation path 410 ... First branch anode gas supply path 412 ... First anode gas supply amount adjustment valve 414 ... First anode exhaust gas path 420 .. Second branch anode gas supply path 422 ... second anode gas supply amount adjustment valve 424 ... second anode exhaust gas flow path 430 ... first three-way adjustment valve 432 ... first anode suction path 434. .. First anode circulation path 440 ... second three-way regulating valve 442 ... second anode suction path 444 ... second anode circulation path 500, 500b, 500c, 500d ... control section 900, 900b, 900c, 900d ... Fuel cell system

Claims (15)

A fuel cell system,
A first fuel cell stack having a first internal reaction gas flow path;
A second fuel cell stack having a second internal reaction gas flow path;
A gas suction part for sucking the gas in the first internal reaction gas channel by utilizing the kinetic energy of the exhaust gas from the second internal reaction gas channel;
A fuel cell system comprising: The fuel cell system according to claim 1, further comprising:
A first supply path which is a predetermined reaction gas supply path connected to the first internal reaction gas path;
A second supply path that is a supply path for the reaction gas connected to the second internal reaction gas flow path;
The supply amount of the reaction gas to at least one of the first internal reaction gas channel and the second internal reaction gas channel is connected to at least one of the first supply channel and the second supply channel A supply amount adjusting unit for adjusting
A control unit for controlling the operation of each unit;
With
The controller is
As a control mode of the supply amount adjusting unit, a supply amount ratio, which is a ratio of the reaction gas supply amount to the second internal reaction gas channel with respect to the reaction gas supply amount to the first internal reaction gas channel, is compared. A standard mode for controlling the supply amount adjustment unit so as to be a small value, and a discharge mode for controlling the supply amount adjustment unit so that the supply amount ratio becomes a relatively large value,
By controlling the supply amount adjusting unit according to the discharge mode, the gas suction unit sucks the gas in the first internal reaction gas flow path,
Fuel cell system. The fuel cell system according to claim 2, further comprising:
A reaction gas supply unit connected to the first supply path and the second supply path and supplying the reaction gas to each of the supply paths;
The supply amount adjusting unit is a valve connected to at least one of the first supply path and the second supply path, and is capable of adjusting the flow rate of the reaction gas in the supply path to which the valve is connected. Having a valve,
Fuel cell system. The fuel cell system according to claim 3,
The supply amount adjustment unit has a supply amount adjustment valve provided as the adjustment valve in the first supply path and capable of adjusting the supply amount of the reaction gas to the first internal reaction gas flow path,
The controller is
In the standard mode, the opening of the supply amount adjustment valve is set to a relatively large value,
In the discharge mode, the opening of the supply amount adjustment valve is set to a relatively small value.
Fuel cell system. The fuel cell system according to claim 3,
The supply amount adjustment unit includes a supply amount adjustment valve provided as the adjustment valve in the second supply path and capable of adjusting the supply amount of the reaction gas to the second internal reaction gas channel,
The controller is
In the standard mode, the opening of the supply amount adjustment valve is set to a relatively small value,
In the discharge mode, the opening of the supply amount adjustment valve is set to a relatively large value.
Fuel cell system. The fuel cell system according to any one of claims 2 to 5, further comprising:
A failure determination unit for determining the presence or absence of a failure due to accumulation of water in the first internal reaction gas flow path;
The controller is
When it is determined that there is a possibility of a failure by the failure determination unit, the supply amount adjustment unit is controlled according to the discharge mode,
When it is determined that there is no possibility of a failure by the failure determination unit, the supply amount adjustment unit is controlled according to the standard mode.
Fuel cell system. The fuel cell system according to claim 6, further comprising:
A humidity sensor for measuring the humidity of the exhaust gas from the first internal reaction gas flow path;
The defect determination unit determines that there is a possibility of a defect when the humidity measured by the humidity sensor is equal to or higher than a humidity threshold;
Fuel cell system. The fuel cell system according to claim 6,
The first fuel cell stack includes a plurality of single cells,
The fuel cell system further includes a voltage sensor for measuring a voltage of each single cell,
The defect determination unit performs the determination based on the voltage of each single cell.
Fuel cell system. The fuel cell system according to claim 6, further comprising:
A power sensor for measuring generated power including at least the power of the first fuel cell;
The defect determination unit calculates an integrated power that is an integrated value of the generated power, and determines that there is a possibility of a defect each time the integrated power increases by a predetermined reference integrated power,
The control unit controls the supply amount adjusting unit according to the discharge mode every time the defect determination unit determines that there is a possibility of a defect, and the standard mode after the discharge process according to the standard mode. A series of processes including a standard process for controlling the supply amount adjusting unit,
Fuel cell system. The fuel cell system according to claim 6, further comprising:
A temperature sensor for measuring an operating temperature reflecting the temperature of the first internal reaction gas flow path;
The defect determination unit determines that there is a possibility of a defect when the operating temperature is equal to or lower than a temperature threshold;
Fuel cell system. The fuel cell system according to any one of claims 1 to 10, further comprising:
A first exhaust gas passage connected to the first internal reaction gas passage;
A second exhaust gas flow path connected to the second internal reaction gas flow path;
With
The gas suction part is
A first turbine provided in the first exhaust gas flow path;
A second turbine mechanically connected to the first turbine and provided in the second exhaust gas flow path,
The first turbine and the second turbine are:
The exhaust gas from the second internal reaction gas flow path that flows through the second exhaust gas flow path drives the second turbine, so that the second turbine drives the first turbine, and the first turbine is Configured to suck the gas in the first internal reaction gas flow path;
Fuel cell system. The fuel cell system according to any one of claims 1 to 10, further comprising:
A first exhaust gas passage connected to the first internal reaction gas passage;
A second exhaust gas flow path connected to the second internal reaction gas flow path;
With
The gas suction part is
An ejector which is provided in the second exhaust gas flow path and communicates with the first exhaust gas flow path;
The ejector utilizes the flow of the exhaust gas from the second internal reaction gas flow channel that flows through the second exhaust gas flow channel, thereby allowing the ejector in the first internal reaction gas flow channel to pass through the first exhaust gas flow channel. Configured to aspirate gas,
Fuel cell system. The fuel cell system according to claim 1, further comprising:
A first exhaust gas passage connected to the first internal reaction gas passage;
A second exhaust gas flow path connected to the second internal reaction gas flow path;
A reaction gas supply unit for supplying a predetermined reaction gas;
A first supply path for connecting the reactive gas supply unit and the first internal reactive gas flow path and supplying the reactive gas to the first internal reactive gas flow path;
A second supply path for connecting the reaction gas supply unit and the second internal reaction gas flow path and supplying the reaction gas to the second internal reaction gas flow path;
The gas suction part is
A first turbine provided in the first exhaust gas flow path;
A second turbine mechanically connected to the first turbine and provided in the second exhaust gas flow path,
The first turbine and the second turbine are:
(A) The ratio of the flow rate of the exhaust gas from the second internal reaction gas channel flowing through the second exhaust gas channel to the flow rate of the exhaust gas from the first internal reaction gas channel flowing through the first exhaust gas channel. When the flow rate ratio is relatively large, exhaust gas from the second internal reaction gas flow path that flows through the second exhaust gas flow path drives the second turbine, so that the second turbine causes the first turbine to move. While driving, the first turbine sucks the gas in the first internal reaction gas flow path,
(B) When the flow rate ratio is relatively small, the exhaust gas from the first internal reaction gas channel that flows through the first exhaust gas channel drives the first turbine, so that the first turbine is The second turbine is configured to drive the second turbine and to suck the gas in the second internal reaction gas flow path.
Fuel cell system. A method for controlling a fuel cell system, comprising:
The fuel cell system includes:
A first fuel cell stack having a first internal reaction gas flow path;
A second fuel cell stack having a second internal reaction gas flow path;
A first supply path which is a predetermined reaction gas supply path connected to the first internal reaction gas path;
A second supply path that is a supply path for the reaction gas connected to the second internal reaction gas flow path;
A gas suction part for sucking the gas in the first internal reaction gas channel by utilizing the kinetic energy of the exhaust gas from the second internal reaction gas channel;
The supply amount of the reaction gas to at least one of the first internal reaction gas channel and the second internal reaction gas channel is connected to at least one of the first supply channel and the second supply channel A supply amount adjusting unit for adjusting
With
The control method is:
(A) A supply amount ratio, which is a ratio of the reaction gas supply amount to the second internal reaction gas flow channel to the reaction gas supply amount to the first internal reaction gas flow channel, is a relatively small value. Controlling the supply amount adjusting unit in a standard mode for controlling the supply amount adjusting unit;
(B) By controlling the supply amount adjustment unit in a discharge mode for controlling the supply amount adjustment unit so that the supply amount ratio becomes a relatively large value, the first internal reaction gas flow in the gas suction unit A step of sucking the gas in the road;
A control method comprising: A computer program for causing a computer to execute processing for controlling a fuel cell system,
The fuel cell system includes:
A first fuel cell stack having a first internal reaction gas flow path;
A second fuel cell stack having a second internal reaction gas flow path;
A first supply path which is a predetermined reaction gas supply path connected to the first internal reaction gas path;
A second supply path that is a supply path for the reaction gas connected to the second internal reaction gas flow path;
A gas suction part for sucking the gas in the first internal reaction gas channel by utilizing the kinetic energy of the exhaust gas from the second internal reaction gas channel;
The supply amount of the reaction gas to at least one of the first internal reaction gas channel and the second internal reaction gas channel is connected to at least one of the first supply channel and the second supply channel A supply amount adjusting unit for adjusting
With
The computer program is
(A) In a computer, a supply amount ratio, which is a ratio of the reaction gas supply amount to the second internal reaction gas flow channel to the reaction gas supply amount to the first internal reaction gas flow channel, is a relatively small value. A function of controlling the supply amount adjustment unit in a standard mode for controlling the supply amount adjustment unit,
(B) By causing the computer to control the supply amount adjustment unit in a discharge mode for controlling the supply amount adjustment unit so that the supply amount ratio becomes a relatively large value, the gas suction unit causes the first internal A function of sucking the gas in the reaction gas flow path;
A computer program that realizes

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