JP2021150005A - Fuel battery system - Google Patents

Abstract

To provide a fuel battery system capable of suppressing deterioration of a traveling performance of a vehicle while executing characteristic recovery processing.SOLUTION: A fuel battery system (13) having a fuel battery (21) including a plurality of cells generating power by using a fuel, comprises: operation devices (50D, 60D, and 65D) making at least one cell of a plurality of cells operate; recovery processing devices (50C, 60C, and 65D) executing recovery processing for recovering a poisoning state to a normal state on at least one cell of the plurality of cells; a recovery necessary cell selection part (81) selecting a recovery necessary cell (Cc) requiring an execution of the recovery processing from the plurality of cells; an operation cell selection part (82) selecting an operation cell (Cd) as at least one cell of the cells other than the recovery necessary cell of the plurality of cells; a recovery processing control part (86) executing the recovery processing on the recovery necessary cell by controlling each recovery processing device; and an operation control part (85) operating the operation cell by controlling each operation device.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fuel cell system and particularly relates to a technique for recovering the characteristics of a poisoned cell.

A so-called fuel cell vehicle (hereinafter, also referred to as FCV (Fuel Cell Vehicle)) uses hydrogen stored in a hydrogen tank and oxygen contained in the air taken in from the outside of the FCV to generate a power generation reaction of an electrode catalyst in the fuel cell. Drive by. This fuel cell has an air electrode in which an air reaction occurs and a hydrogen electrode in which a hydrogen reaction occurs. Further, in each of the electrodes, Pt is mainly used as an electrode catalyst. Therefore, there is a risk of being poisoned by sulfur impurities contained in the air taken in at the air electrode, and at the hydrogen electrode, due to sulfur impurities mixed in during the production of hydrogen gas as fuel or sulfur impurities generated by decomposition of FC members. ..

When the electrode catalyst is poisoned by sulfur impurities in this way, there is a problem that the power generation performance of the electrode catalyst is lowered. In particular, in hot spring areas, near intersections with heavy traffic, and in tunnels, the proportion of sulfur impurities contained in the air is relatively high, so that the electrode catalyst is significantly poisoned.
Therefore, as a method for removing sulfur from the electrode catalyst poisoned by sulfur impurities (characteristic recovery treatment), a technique has been developed in which the electrode catalyst is oxidized and removed by putting it in a high potential state (about 0.9V). (Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-40426

However, in the technique disclosed in Patent Document 1, it is necessary to stop the output of the fuel cell in order to bring the electrode catalyst into a high potential state. That is, when the output of the fuel cell is stopped, the output such as the driving force of the FCV is greatly reduced, so that there is a problem that the sulfur of the poisoned electrode catalyst cannot be removed when the FCV is running.
The present invention has been made in view of such a problem, and an object of the present invention is to provide a fuel cell system capable of suppressing deterioration of running performance of a vehicle while executing characteristic recovery processing.

In order to achieve the above object, the fuel cell system of the present invention is a fuel cell system having a fuel cell including a plurality of cells that generate electricity using fuel, and operates at least one of the plurality of cells. An operating device to be operated, a recovery processing device that executes a characteristic recovery process for recovering a poisoned state to a normal state in at least one of the plurality of cells, and an execution of the characteristic recovery process among the plurality of cells. A recovery-requiring cell selection unit that selects a recovery-requiring cell that is a required cell, and an operating cell selection unit that selects an operating cell that is at least one cell other than the recovery-requiring cell among the plurality of cells. It is characterized by including a recovery processing control unit that controls the recovery processing device and executes the characteristic recovery process on the recovery-required cell, and an operation control unit that controls the operating device to operate the operating cell. do.

As a result, among the plurality of cells of the fuel cell, the fuel cell operates the operating cell set by the operating cell selection unit while executing the characteristic recovery processing on the recovery-requiring cell set by the recovery-requiring cell selection unit. It is possible to recover the poisoned state of the recovery-requiring cell without stopping the power generation.
As another embodiment, the voltage detection unit for detecting the voltage value of each of the plurality of cells is provided, and the recovery-required cell selection unit has a predetermined value of the voltage value detected by the voltage detection unit among the plurality of cells. It is preferable to select the following cells as the recovery-requiring cells.

As a result, by executing the characteristic recovery processing of the cells whose voltage value detected by the voltage detection unit is equal to or less than the predetermined value among the plurality of cells, the characteristic recovery processing is performed on the cells whose voltage has dropped due to the poisoned state. It is made feasible.
As another aspect, the storage unit for storing the time when the characteristic recovery process of each of the plurality of cells is last is provided, and the recovery-requiring cell selection unit is stored in the storage unit among the plurality of cells. It is preferable to select a cell that has passed a certain period of time since the last characteristic recovery process as the cell requiring recovery.

As a result, by executing the characteristic recovery processing of the cells in which a certain period of time has passed since the last characteristic recovery processing stored in the storage unit among the plurality of cells, the poisoned cells over time are periodically poisoned. It is possible to recover.
As another aspect, it is preferable that the recovery processing control unit ends the characteristic recovery processing when a predetermined time elapses from the start of the characteristic recovery processing.

As a result, by ending the characteristic recovery process when a predetermined time elapses from the start of the characteristic recovery process, it is possible to set the end time of the characteristic recovery process with a simple configuration.
As another embodiment, the voltage detection unit for detecting the voltage value of each of the plurality of cells is provided, and the recovery processing control unit changes the predetermined time according to the voltage value detected by the voltage detection unit. Is preferable.

As a result, by changing the time for characteristic recovery processing by the recovery processing device according to the voltage value detected by the voltage detection unit, the degree of poisoning can be estimated from the degree of voltage drop, and the necessary and sufficient characteristic recovery. Processing is possible.
As another aspect, it is preferable that the operating cell selection unit selects the operating cell so that at least one of the recovery-requiring cells is sandwiched between the operating cells.

As a result, by selecting the operating cell so that at least one of the recovery-requiring cells is sandwiched between the operating cells, for example, the heat generated in the operating cell is used to heat the recovery-requiring cell or the recovery-requiring cell is generated. It is possible to heat the operating cell by using the heat generated.
As another aspect, it is preferable that the fuel cell system includes a battery for storing electric power generated by the fuel cell, and the fuel cell system outputs electric power through the battery.

As a result, by outputting electric power through the battery provided in the fuel cell system and executing the characteristic recovery process, even if the output of the fuel cell is temporarily reduced, the electric power is stored in the battery. It is possible to output electric power.

According to the fuel cell system of the present invention, among a plurality of cells of the fuel cell, the operating cell set by the operating cell selection unit is operated while executing the characteristic recovery processing on the recovery-requiring cell set by the recovery-requiring cell selection unit. Therefore, it is possible to recover the poisoned state of the recovery-requiring cell without stopping the power generation by the fuel cell. That is, it is possible to suppress the deterioration of the running performance of the vehicle while executing the characteristic recovery process.

It is a schematic block diagram of a vehicle. It is a block diagram of a fuel cell. It is a block diagram which showed the connection structure of the ECU which concerns on the control of the fuel cell system which concerns on this invention. It is a flowchart which shows the routine of the control procedure of the fuel cell system which concerns on this invention which the ECU executes. It is a flowchart which shows the routine of the control procedure of the recovery-requiring cell setting control executed by the recovery-requiring cell setting part. It is a flowchart which shows the routine of the control procedure of the operation cell setting control executed by the operation cell setting part. It is a flowchart which shows the routine of the control procedure of the recovery process control executed by the recovery process control unit. It is a figure which arranged the graph which showed an example of the change of the voltage of each cell detected by a voltage sensor, and the change of SOC of a battery detected by an SOC sensor by the control of the fuel cell system which concerns on this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
With reference to FIG. 1, a schematic configuration diagram of the vehicle 1 is shown. The vehicle 1 is equipped with a drive wheel 3, a driven wheel 5, a motor 7, a speed reducer 9, a drive shaft 11, and a fuel cell system 13. The vehicle 1 can drive the drive wheels 3 by rotating the drive shaft 11 via the speed reducer 9 by the motor 7 supplied with electric power from the fuel cell system 13.

That is, the vehicle 1 is a so-called FCV that generates electric energy from hydrogen fuel and oxygen contained in the air outside the vehicle 1. Further, the vehicle 1 is also a so-called hybrid vehicle capable of driving the motor 7 with the electric power stored in the battery 31 and traveling.
The fuel cell system 13 includes a fuel cell 21, a hydrogen tank 23, a compressor 25, a battery 31, and an inverter 33. The fuel cell 21 is a hydrogen fuel cell capable of generating (generating) electric energy when hydrogen (fuel) and oxygen are combined to generate water. The detailed configuration of the fuel cell 21 will be described later.

The hydrogen tank 23 is a tank that stores hydrogen under high pressure. The hydrogen stored in the hydrogen tank 23 is supplied to the fuel cell 21 via the hydrogen supply path 23a. Further, the hydrogen not consumed in the fuel cell 21 is stored again in the hydrogen tank 23 via the hydrogen discharge path 23b. The compressor 25 is a suction device that sucks air from the outside of the vehicle 1. The air sucked by the compressor 25 is supplied to the fuel cell 21 via the air supply path 25a.

As a result, the fuel cell 21 can generate electricity by combining the hydrogen stored in the hydrogen tank 23 with the oxygen contained in the air sucked by the compressor 25 from the outside of the vehicle 1. The fuel cell 21 generated in this way discharges substances other than water vapor, which is water generated during power generation, and oxygen contained in the air, to the outside of the vehicle 1 via the air discharge path 25b.

The battery 31 is, for example, a lithium ion secondary battery that can be repeatedly charged and discharged. The inverter 33 is a conversion device capable of boosting or stepping down the voltage and converting an alternating current to a direct current or a direct current to an alternating current. The inverter 33 is electrically connected to the motor 7, the fuel cell 21, and the battery 31.
As a result, the inverter 33 boosts or lowers the DC current generated by the fuel cell 21 and stores it in the battery 31, or converts the power stored in the battery 31 into a three-phase AC current to convert the motor 7 into a three-phase AC current. Can be supplied to. Therefore, the vehicle 1 can store the electric power generated by the fuel cell 21 in the battery 31 and drive the motor 7 by using the electric power stored in the battery 31 to travel.

With reference to FIG. 2, a configuration diagram of the fuel cell 21 is shown. In the fuel cell 21, first cell C1, second cell C2, third cell C3, and fourth cell C4 (a plurality of cells) are arranged side by side in a row. Each cell is partitioned by an anode current collector plate 44, a first cathode current collector plate 45a, a second cathode current collector plate 45b, a third cathode current collector plate 45c, and a fourth cathode current collector plate 45d.

The first cell C1 is configured such that the membrane electrode assembly 43 is sandwiched between the anode separator 41 and the cathode separator 42. The anode separator 41 is a porous material that uniformly diffuses hydrogen supplied from the hydrogen supply path 23a onto the contact surface of the membrane electrode assembly 43. The cathode separator 42 is a porous material that uniformly diffuses the air supplied from the air supply path 25a onto the contact surface of the membrane electrode assembly 43.

The membrane electrode assembly 43 includes a polymer electrolyte membrane 43a, a catalyst layer 43b, and a gas diffusion layer 43c. The polyelectrolyte membrane 43a is a solid polymer membrane such as a proton exchange membrane or an anion exchange membrane. The catalyst layer 43b is formed by supporting a catalyst of a noble metal such as platinum or palladium on, for example, a porous carbon film. The catalyst layer 43b is arranged on both sides of the polymer electrolyte membrane 43a. The gas diffusion layer 43c is formed of, for example, a conductive porous body or carbon fiber, and can diffuse hydrogen and air. The gas diffusion layer 43c is arranged so as to further sandwich the catalyst layer 43b.

As a result, in the first cell C1, the hydrogen supplied to the anode separator 41 is diffused by the gas diffusion layer 43c and uniformly supplied to the catalyst layer 43b and the polymer electrolyte membrane 43a, and the air supplied to the cathode separator 42. Is diffused by the gas diffusion layer 43c and uniformly supplied to the catalyst layer 43b and the polymer electrolyte membrane 43a, and hydrogen ions and oxygen ions are combined by the polymer electrolyte membrane 43a and the catalyst layer 43b to generate water. , Is discharged from the air discharge path 25b as water vapor.

At this time, the electrons generated when hydrogen is decomposed into hydrogen ions move to the anode side via the anode current collecting plate 44 and the anode electric wire 41L extending to the anode side, and decompose the oxygen in the cathode separator 42 into oxygen ions. The electrons required for this are supplied from the cathode side via the first cathode current collecting plate 45a and the cathode wire 42L extending to the cathode side. As a result, hydrogen ions are supplied from the anode side of the membrane electrode assembly 43, and oxygen ions are supplied from the cathode side to bond hydrogen and oxygen. Further, by combining hydrogen and oxygen in the first cell C1 to generate water in this way, movement of electrons is generated and power generation can be performed. Since the second cell C2, the third cell C3, and the fourth cell C4 have the same configuration, the description thereof will be omitted.

The anode separator 41 of the first cell C1 is provided with a first hydrogen supply valve 51a capable of adjusting and closing the amount of hydrogen supplied from the hydrogen supply path 23a. Further, the anode separator 41 is provided with a first hydrogen discharge valve 51b capable of adjusting and closing the amount of hydrogen discharged to the hydrogen discharge path 23b. Similarly, the cathode separator 42 of the first cell C1 is provided with a first air supply valve 51c capable of adjusting and closing the amount of air supplied from the air supply path 25a.

Further, the cathode separator 42 is provided with a first air discharge valve 51d capable of adjusting and closing the amount of air discharged to the air discharge path 25b. Further, although not shown, the first hydrogen supply valve 51a, the first hydrogen discharge valve 51b, the first air supply valve 51c, and the first air discharge valve 51d are electrically connected to the ECU 80 described later, respectively. Can control the opening and closing of.

By controlling the first hydrogen supply valve 51a, the first hydrogen discharge valve 51b, the first air supply valve 51c, and the first air discharge valve 51d, respectively, the flow rates of hydrogen and air in the anode separator 41 and the cathode separator 42 can be adjusted. can. By adjusting the flow rates of hydrogen and air of the anode separator 41 and the cathode separator 42 in this way, the flow rates of hydrogen and air are increased to promote power generation in the first cell C1, and hydrogen is supplied to the anode separator 41. The hydrogen in the anode separator 41 can be consumed.

Similarly, in the second cell C2, the third cell C3, and the fourth cell C4, the second hydrogen supply valve 52a, the second hydrogen discharge valve 52b, the second air supply valve 52c, the second air discharge valve 52d, and the third cell Hydrogen supply valve 53a, third hydrogen discharge valve 53b, third air supply valve 53c and third air discharge valve 53d, fourth hydrogen supply valve 54a, fourth hydrogen discharge valve 54b, fourth air supply valve 54c and fourth air Since the discharge valve 54d is provided and has the same configuration, the description thereof is omitted here. Further, for convenience of explanation, the supply valves 51a, 51c, 52a, 52c, 53a, 53c, 54a, 54c, and the discharge valves 51b, 51d, 52b, 52d, 53b, 53d, 54b, 54d are collectively referred to as the control valve 50. say.

The first cathode current collector plate 45a that separates the first cell C1 and the second cell C2 is connected to the cathode electric wire 42L via the first cathode switch 61. The first cathode switch 61 is a switch capable of switching between energization (ON) and insulation (OFF). In other words, the first cathode switch 61 can lower the potential of the first cell C1 and discharge to the cathode electric wire 42L by turning it on, and can suppress the lowering of the potential of the first cell C1 by turning it off.

The first cathode switch 61 is electrically connected to the ECU 80 described later and can be controlled. Regarding the second cathode switch 62, the third cathode switch 63, and the fourth cathode switch 64 that are connected to the cathode wire 42L from the second cathode current collector plate 45b, the third cathode current collector plate 45c, and the fourth cathode current collector plate 45d. Since this has the same configuration, the description thereof will be omitted. Further, for convenience of explanation, the first cathode switch 61, the second cathode switch 62, the third cathode switch 63, and the fourth cathode switch 64 are also collectively referred to as a cathode output switch 60.

The anode current collector plate 44 is connected to the anode electric wire 41L via a first anode switch 66 similar to the first switch 61. The first anode switch 66 is a switch capable of switching between energization (ON) and insulation (OFF). In other words, the first anode switch 66 can lower the potential of the first cell C1 and discharge to the anode electric wire 41L by turning it on, and can suppress the lowering of the potential of the first cell C1 by turning it off.

The first anode switch 66 is electrically connected to the ECU 80 described later and can be controlled. Regarding the second anode switch 67, the third anode switch 68, and the fourth anode switch 69 connected to the anode electric wire 41L from the first cathode current collector plate 45a, the second cathode current collector plate 45b, and the third cathode current collector plate 45c. Since this has the same configuration, the description thereof will be omitted. Further, for convenience of explanation, the first anode switch 66, the second anode switch 67, the third anode switch 68, and the fourth anode switch 69 are also collectively referred to as an anode output switch 65.

As described above, the fuel cell 21 has a cathode output switch on the anode current collector plate 44, the first cathode current collector plate 45a, the second cathode current collector plate 45b, the third cathode current collector plate 45c, and the fourth cathode current collector plate 45d. By disposing the 60 and the anode output switch 65, for example, the first cathode switch 61 and the first anode switch 66 are turned on, and the other cathode output switch 60 and the anode output switch 65 are turned off. The cell (operating cell Cd described later) can be selectively operated.

A first voltage sensor 71 is arranged between the first cathode current collector plate 45a and the first switch 61. The first voltage sensor 71 is a sensor that detects the voltage value of the current that is energized from the first cathode current collector plate 45a to the cathode electric wire 42L. Regarding the second voltage sensor 72, the third voltage sensor 73, and the fourth voltage sensor 74 connected to the cathode wire 42L from the second cathode current collector plate 45b, the third cathode current collector plate 45c, and the fourth cathode current collector plate 45d. Since this has the same configuration, the description thereof will be omitted. Further, for convenience of explanation, the first voltage sensor 71, the second voltage sensor 72, the third voltage sensor 73, and the fourth voltage sensor 74 are also collectively referred to as a voltage sensor (voltage detection unit) 70.

Returning to FIG. 1, the SOC sensor 75 is arranged in the battery 31. The SOC sensor 75 is a sensor capable of detecting the SOC (State of Charge), which is the charge rate of the battery 31.
With reference to FIG. 3, the connection configuration of the ECU 80 related to the control of the fuel cell system 13 according to the present invention is shown in a block diagram.

The ECU 80 is a control device for performing comprehensive control including operation control of the fuel cell system 13, such as an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like. Is configured to include. A voltage sensor 70 and a SOC sensor 75 are electrically connected to the input side of the ECU 80. As a result, information on the voltage value of each cell is input from the voltage sensor 70, and information on the SOC of the battery 31 is input from the SOC sensor 75.

On the other hand, a control valve 50 (50D and 50C described later), a cathode output switch 60 (60D and 60C described later), and an anode output switch 65 (65D and 65C described later) are electrically connected to the output side of the ECU 80. There is. Thereby, by controlling the control valve 50, the supply and discharge of hydrogen and air in each cell can be controlled, and by controlling the cathode output switch 60 and the anode output switch 65, the discharge from each cell can be adjusted. The potential of each cell can be adjusted individually.

Further, the ECU 80 includes a recovery required cell setting unit (recovery required cell selection unit) 81, an operating cell setting unit (operating cell selection unit) 82, a timekeeping unit 83, a storage unit 84, an operation control unit 85, and a recovery processing control unit 86. Is provided. The recovery-requiring cell setting unit 81 is a setting unit that executes recovery-requiring cell setting control described later and sets the recovery-requiring cell Cc based on the information regarding the voltage value of each cell input from the voltage sensor 70.

Here, the recovery-required cell Cc is, for example, platinum contained in the membrane electrode assembly 43 in the cell, particularly in the catalyst layer 43b, combined with sulfur or the like contained in the air to become platinum sulfide, resulting in reduced power generation performance. It is a cell in a state where it is in a state of being poisoned by sulfur (hereinafter referred to as a sulfur-poisoned state). This sulfur-poisoned cell has a characteristic that the voltage value is lower than that of a normal cell because the power generation performance is deteriorated.

The operating cell setting unit 82 executes the operating cell setting control described later based on the information regarding the SOC of the battery 31 input from the SOC sensor 75 and the recovery required cell Cc set by the recovery required cell setting unit 81, and operates. This is a setting unit for setting the cell Cd. Here, the operating cell Cd is at least one cell among the cells other than the recovery-required cell Cc, and as will be described later, it may be singular or plural.

The timekeeping unit 83 is a timer that measures the passage of time. The storage unit 84 is a memory that stores various information in the ECU 80. The operation control unit 85 is a control unit that controls the control valve (operation device) 50D, the cathode output switch (operation device) 60D, and the anode output switch (operation device) 65D of the operation cell Cd set by the operation cell setting unit 82. be. The recovery processing control unit 86 includes a control valve (recovery processing device) 50C, a cathode output switch (recovery processing device) 60C, and an anode output switch (recovery processing device) 65C of the recovery-requiring cell Cc set by the recovery-requiring cell setting unit 81. It is a control unit that controls.

With reference to FIG. 4, a routine showing a control procedure of the fuel cell system 13 according to the present invention, which is executed by the ECU 80, is shown in a flowchart, and will be described below with reference to the flowchart. First, as an overall flow, in step S10, the recovery-requiring cell setting unit 81 executes the recovery-requiring cell setting control to set the recovery-requiring cell Cc described above. After that, in step S20, the operating cell setting unit 82 executes the operating cell setting control to set the operating cell Cd described above. Then, in step S30, while operating the operating cell Cd, the recovery processing control (characteristic recovery processing) for recovering the sulfur poisoned state of the recovery-required cell Cc is executed, and this routine is repeatedly executed.

As a result, among the plurality of cells, the recovery-requiring cell Cc and the operating cell Cd are set, respectively, and the sulfur-poisoned state of the recovery-requiring cell Cc is recovered while the operating cell Cd is operating, whereby the fuel cell 21 The recovery-required cell Cc can be recovered from the sulfur poisoned state without stopping the power generation by the fuel cell.
With reference to FIG. 5, a flowchart showing a control procedure for the recovery-requiring cell setting control executed by the recovery-requiring cell setting unit 81 is shown. In step S11, it is determined by the recovery processing control (step S30) whether or not there is a cell for which a certain period of time has passed after recovering from the sulfur poisoned state. If the determination result in step S11 is true (Yes) and it is determined that there is a cell for which a certain period of time has passed since the recovery from the sulfur poisoning state, the process proceeds to step S14, and the cell for which the certain time has passed (corresponding cell) is entered. ) Is set as the recovery-required cell Cc, and then the process proceeds to step S16. In step S16, the voltage value of the recovery-requiring cell Cc is stored in the storage unit 84, and the recovery-requiring cell setting control is terminated. On the other hand, if the determination result in step S11 is false (No) and it is determined that there is no cell for which a certain period of time has passed after recovering from the sulfur poisoned state, the process proceeds to step S12.

In step S12, it is determined whether or not there is a cell whose voltage value is equal to or less than a predetermined value based on the information regarding the voltage value of each cell input from the voltage sensor 70. When the determination result in step S11 is false (No) and it is determined that there is no cell whose voltage value is equal to or less than the predetermined value, the recovery required cell setting control and the control of the fuel cell system 13 (flow in FIG. 4) are terminated. On the other hand, when the determination result in step S11 is true (Yes) and it is determined that there is a cell whose voltage value is equal to or less than a predetermined value, the process proceeds to step S15, and the cell having the lowest voltage value is set as the recovery required cell Cc. To step S17 and thereafter. In step S17, the voltage value of the recovery-requiring cell Cc is stored in the storage unit 84, and the recovery-requiring cell setting control is terminated.

As described above, in steps S11 to S15, the cell estimated to be in the sulfur-poisoned state again after a certain period of time has passed after recovering from the sulfur-poisoned state is set as the recovery-required cell Cc (Yes, in step S11, Yes, In step S14), even if a certain period of time has not passed since the recovery from the sulfur poisoned state (No in step S11), the cell whose voltage value is equal to or less than a predetermined value and is estimated to be in the sulfur poisoned state is displayed. It can be set as the recovery-required cell Cc (Yes in step S12, step S15). If there is no cell whose voltage value is less than or equal to the predetermined value (No in step S12), it is estimated that there is no cell presumed to be in a sulfur poisoned state, and recovery required cell setting control and fuel cell system 13 control. To finish.

As a result, in the recovery-requiring cell setting control in step S10, the cell that needs to be recovered from the sulfur poisoned state can be accurately estimated by the recovery processing control (step S30) and set as the recovery-requiring cell Cc.
Returning to FIG. 4, when the recovery-requiring cell Cc is set by the recovery-requiring cell setting control in step S10, the process proceeds to step S20 and the operation cell setting control is executed.

With reference to FIG. 6, a flowchart showing a control procedure for operating cell setting control executed by the operating cell setting unit 82 is shown. In step S21, it is determined whether or not the SOC of the battery 31 is a certain value (for example, 50%) or more based on the information regarding the SOC of the battery 31 input from the SOC sensor 75. When it is determined that the determination result in step S21 is true (Yes) and the SOC of the battery 31 is equal to or higher than a certain value, the process proceeds to step S22, and the determination result in step S21 is false (No) and the SOC of the battery 31 is less than a certain value. If it is determined that there is, the process proceeds to step S23.

In step S22, at least one cell adjacent to the recovery-required cell Cc is set as the operating cell Cd, and the operating cell setting control is terminated. Here, at least one cell adjacent to the recovery-requiring cell Cc is, for example, the first cell C1 and the third cell C3 when the recovery-requiring cell Cc is the second cell C2, according to FIG. When the recovery-required cell Cc is the first cell C1, it means the second cell C2.

As a result, the recovery processing control can be satisfactorily executed by utilizing the heat generated when the cell adjacent to the recovery required cell Cc is operated. If the recovery-requiring cell Cc is the second cell C2, only one of the first cell C1 and the third cell C3 may be set as the operating cell Cd, and the recovery-requiring cell Cc is the first. In the case of cell C1, the second cell C2 and the fourth cell C4 may be set as the operating cell Cd, and the recovery required cell Cc may be set according to the heat exhaust property of each cell and the torque required by the driver of the vehicle 1. If it is a cell other than the above, the other cell may be appropriately set as the operating cell Cd.

On the other hand, in step S23, all the cells other than the recovery-required cell Cc are set as the operating cell Cd, and the operating cell setting control is terminated. As a result, the power generation during the execution of the recovery processing control for the recovery-requiring cell Cc can be supplemented by all the cells other than the recovery-requiring cell Cc. Returning to FIG. 4, after setting the operating cell Cd by the operating cell setting control in step S20, the process proceeds to step S30 to execute the recovery processing control.

With reference to FIG. 7, a flowchart showing a control procedure for recovery processing control executed by the recovery processing control unit 86 is shown. In step S31, all the control valves 50C of the recovery-requiring cell Cc are opened (for example, if the recovery-requiring cell Cc is the first cell C1, the first hydrogen supply valve 51a, the first hydrogen discharge valve 51b, and the first air supply valve are opened. 51c and the first air discharge valve 51d are opened), and the cathode output switch 60C and the anode output switch 65C of the recovery-requiring cell Cc are turned off (for example, if the recovery-requiring cell Cc is the first cell C1, the first cathode switch 61 And the first anode switch 65 is turned off), and the process proceeds to step S32.

Here, as described above, when the cathode output switch 60C and the anode output switch 65C are turned off, it is possible to prevent the potential of the recovery-requiring cell Cc from dropping. Further, by opening all the control valves 50C of the recovery-requiring cell Cc, the flow rates of hydrogen and air can be increased to promote power generation in the recovery-requiring cell Cc. As a result, the potential of the recovery-requiring cell Cc can be increased by step S31.

In step S32, it is determined whether or not the set time A (predetermined time) has elapsed since the start of increasing the potential of the recovery-requiring cell Cc in step S31 based on the timed by the time measuring unit 83. Here, the set time A means that the voltage value Cc of the recovery-requiring cell is lower than a predetermined value based on the voltage value of the recovery-requiring cell Cc stored in the storage unit 84 in step S16 or step S17 of the recovery-requiring cell setting control. The lower the value, the longer the set time A is set, and the higher the voltage value of the recovery-required cell is, the shorter the set time A is set. In step S32, step S32 is repeatedly executed while it is determined that the determination result is false (No) and the set time A has not elapsed, and it is determined that the determination result is true (Yes) and the set time A has elapsed. The process proceeds to step S33.

In step S33, all the control valves 50C of the recovery-requiring cell Cc are closed (for example, if the recovery-requiring cell Cc is the first cell C1, the first hydrogen supply valve 51a, the first hydrogen discharge valve 51b, and the first air supply valve are closed. 51c and the first air discharge valve 51d are closed), and the cathode output switch 60C and the anode output switch 65C of the recovery-requiring cell Cc are turned on (for example, if the recovery-requiring cell Cc is the first cell C1, the first cathode switch 61 And the first anode switch 65 is turned ON), and the recovery processing control and the control of the fuel cell system 13 are terminated. By closing all the control valves 50C and turning on the cathode output switch 60C and the anode output switch 65C in this way, the membrane electrode assembly 43 deteriorates due to discharge while the potential of the recovery-requiring cell Cc remains high. Can be suppressed.

As described above, in the recovery processing control, the recovery-requiring cell Cc is recovered from the sulfur poisoned state by maintaining the state in which the potential of the recovery-requiring cell Cc is increased in step S31 for the set time A (step S32). Can be done. Further, by setting the set time A based on the voltage value of the recovery-requiring cell Cc, the time for maintaining the state in which the potential of the recovery-requiring cell Cc is increased according to the degree of sulfur poisoning of the recovery-requiring cell Cc is extended. can.

While the recovery processing control is being executed, the operation control unit 85 can charge the battery 31 by the operation cell Cd by appropriately operating the operation cell Cd set by the operation cell setting unit 82.
Referring to FIG. 8, an example of a change in the voltage of each cell detected by the voltage sensor 70 and a change in the SOC of the battery 31 detected by the SOC sensor 75 under the control of the fuel cell system 13 according to the present invention is shown in the vertical graph. A side-by-side diagram is shown. Hereinafter, the action and effect of the control of the fuel cell system 13 according to the present invention will be described mainly with reference to FIG.

As described above, as each cell generates electricity, platinum is sulphurized by sulfur in the air, and the power generation performance deteriorates. Therefore, the voltage of each cell decreases as the operating time increases. At the time of the first period T1, the second voltage sensor 72 detects that the voltage value of the second cell C2 becomes a predetermined value (less than or equal to the predetermined value) (Yes in step S12 of FIG. 5). In this way, by using the second voltage sensor 72, it is possible to detect that the second cell C2 is in a sulfur poisoned state and set the second cell C2 as the recovery required cell Cc (step S15). The second cell C2 thus set as the recovery-required cell Cc recovers from the sulfur poisoned state by the recovery processing control (steps S31 to S33).

Further, since the SOC of the battery 31 is less than a certain value at the time of the first period T1 (No in step S21 of FIG. 6), the cells other than the second cell C2 are controlled by the operating cell setting control. The third cell C3 and the fourth cell C4 can be set as the operating cell Cd (step S23).
Here, the second cell C2 cannot be discharged because the second switch 62 is turned off in step S31 of the recovery processing control (step S31). On the other hand, by setting cells other than the second cell C2 as the operating cell Cd, the operation control unit 85 operates the first cell C1, the third cell C3, and the fourth cell C4 to generate electric power, and supplies electric power to the battery 31. Can be supplied.

According to FIG. 8, the second cell C2 does not generate power during the period from the first period T1 to the second period T2 (second cell recovery period) due to the recovery processing control. When the vehicle 1 travels or the like during such a second cell recovery period, the electric power stored in the battery 31 is consumed. On the other hand, the operation control unit 85 operates the first cell C1, the third cell C3, and the fourth cell C4 to generate electric power, and supplies electric power to the battery 31 to prevent the SOC of the battery 31 from deteriorating. can.

As a result, the recovery processing control of the second cell C2 can be executed while suppressing the deterioration of the traveling performance of the vehicle 1. Although the recovery processing control of the second cell C2 has been described as an example, the same applies to the case where the recovery processing control of the first cell C1, the third cell C3, and the fourth cell C4 is executed.
After the lapse of the second cell recovery period, the recovery processing control of the first cell C1 is executed during the period from the third period T3 to the fourth period T4 (first cell recovery period) in the same manner as in the second cell recovery period. Here, the difference between the controls of the first cell recovery period and the second cell recovery period is that the voltage value of the first cell C1 is larger than the predetermined value at the third period T3, which is the beginning of the first cell recovery period. The points are that the recovery period of the first cell is shorter than the recovery period of the second cell and that the SOC of the battery 31 is equal to or higher than a certain value.

At the time of the third period T1, it is determined that a certain time has passed since the first cell C1 recovered from the sulfur poisoned state (Yes in step S11 of FIG. 5), and the first cell C1 is set as the recovery required cell Cc. (Step S14), the voltage value of the first cell C1 is stored in the storage unit 84 (step S16). In this way, by setting the cell requiring recovery Cc for a certain period of time after recovering from the sulfur poisoned state (step S14) and executing the recovery processing control (step S30), all the cells have voltage values. Even when is larger than a predetermined value, recovery processing control can be periodically executed for each cell (step S15).

Further, the voltage value of the first cell C1 is stored in the storage unit 84 (step S16), and the higher the voltage value of the first cell C1 is, the shorter the setting time A is set (FIG. 7). Step S32), the time required for recovery processing control can be reduced, in other words, the recovery period of the first cell can be shortened as compared with the recovery period of the second cell.
Further, during the operation cell setting control (step S20), it is determined that the SOC of the battery 31 is equal to or higher than a certain value (Yes in step S21), and the second cell C2 adjacent to the first cell C1 and an arbitrary cell are used. By operating the third cell C3, the heat generated when the second cell C2 generates electricity is transferred to the first cell C1 to improve the efficiency of the recovery process, and the first cell C1 that generates heat by the recovery process control. The second cell C2 can be heated by utilizing the heat of. Further, when the SOC of the battery 31 is equal to or higher than a certain value, it is conceivable that the battery is generated by a so-called regenerative brake that generates electricity when the vehicle 1 decelerates.

Therefore, it is possible to prevent the battery 31 from being fully charged while suppressing the SOC of the battery 31 from being lowered by suspending the fourth cell C4 and operating only the second cell C2 and the third cell C3.
After the lapse of the first cell recovery period, the recovery processing control of the third cell C3 is executed during the period from the fifth period T5 to the sixth period T6 (third cell recovery period) in the same manner as in the second cell recovery period. Here, the difference between each control between the 1st cell recovery period and the 3rd cell recovery period is that the SOC of the battery 31 is equal to or higher than a certain value at the 5th period T5, which is the beginning of the 3rd cell recovery period. be.

As described during the first cell recovery period, during the operating cell setting control (step S20), it is determined that the SOC of the battery 31 is equal to or higher than a certain value (Yes in step S21), and the third cell C3 and Bring up adjacent cells. Here, the cells adjacent to the third cell C3 are the second cell C2 and the fourth cell C4 (see FIG. 2). Therefore, by suspending the first cell C1 and causing the second cell C2 and the fourth cell C4, the heat generated when the second cell C2 and the fourth cell C4 generate electricity is transferred to the third cell C3 for recovery. The processing efficiency can be improved, and the heat of the third cell C3 generated by the recovery processing control can be used to heat the second cell C2 and the fourth cell C4.

As described above, the fuel cell system 13 according to the present invention is a fuel cell system 13 having a fuel cell 21 including a plurality of cells C1 to C4 that generate power using hydrogen, and is at least one of the plurality of cells. The control valve 50D, the cathode output switch 60D, the anode output switch 65D, and at least one of the plurality of cells of the operating cell Cd that operates the cells of the above are subjected to a recovery process for recovering the sulfur poisoning state to a normal state. A control valve 50C, a cathode output switch 60C, and an anode output switch 65C of the recovery-requiring cell Cc, and a recovery-requiring cell setting unit 81 for selecting the recovery-requiring cell Cc, which is a cell that requires execution of recovery processing from a plurality of cells. , The operation cell setting unit 82 that selects the operating cell Cd, which is at least one cell other than the recovery-requiring cell Cc among the plurality of cells, and the control valve 50C of the recovery-requiring cell Cc are controlled to become the recovery-requiring cell Cc. It includes a recovery processing control unit 86 that executes recovery processing, and an operation control unit 85 that controls the control valve 50D of the operating cell Cd to operate the operating cell Cd.

Therefore, among the plurality of cells of the fuel cell 21, the recovery process is executed on the recovery-requiring cell Cc set by the recovery-requiring cell setting unit 81, and the operating cell Cd set by the operating cell setting unit 82 is operated. Therefore, the sulfur poisoned state of the recovery-requiring cell Cc can be recovered without stopping the power generation by the fuel cell 21.
A voltage sensor 70 that detects the voltage value of each of the plurality of cells is provided, and the recovery-requiring cell setting unit 81 sets the recovery-requiring cell among the plurality of cells in which the voltage value detected by the voltage sensor 70 is equal to or less than a predetermined value. Since the Cc is selected and the recovery process is executed, the recovery process can be executed for the cell whose voltage has dropped due to the sulfur poisoning state.

Then, a storage unit 84 that stores the time when the recovery process of each of the plurality of cells is last is provided, and the recovery-required cell setting unit 81 is when the recovery process stored in the storage unit 84 among the plurality of cells is last. Since the cell that has passed a certain period of time from the above is selected as the recovery-requiring cell Cc and the recovery process is executed, the sulfur poisoning of the cell that has been poisoned with sulfur over time can be recovered periodically.
Then, since the recovery processing control unit 86 ends the recovery processing when the set time A elapses after the recovery processing is started, the recovery processing can be set with a simple configuration to set the end time of the recovery processing.

Further, a voltage sensor 70 for detecting the voltage value of each of the plurality of cells is provided, and the recovery processing control unit 86 changes the set time A according to the voltage value detected by the voltage sensor 70. The degree of sulfur poisoning can be estimated from the degree of decrease in the voltage, and the necessary and sufficient recovery treatment can be performed.
Then, the operating cell setting unit 82 selects the operating cell Cd so that at least one of the recovery-required cells Cc is sandwiched between the operating cells Cd. Therefore, for example, the heat generated in the operating cell Cd is used. The operating cell Cd can be warmed by warming the recovery-requiring cell Cc or using the heat generated in the recovery-requiring cell Cc.

A battery 31 for storing the electric power generated by the fuel cell 21 is provided, and the fuel cell system 13 outputs the electric power via the battery 31. Therefore, by executing the recovery process, the fuel is temporarily fueled. Even when the output of the battery 21 is reduced, the power stored in the battery 31 can be output.
The description of the fuel cell system according to the present invention is completed above, but the present invention is not limited to the above embodiment and can be changed without departing from the gist of the present invention.

For example, in the present embodiment, the fuel cell system 13 according to the present invention is mounted on the vehicle 1 which is an FCV, but it may be used for a railroad vehicle, a ship, or an air vehicle.
Further, in the present embodiment, the recovery of the characteristics of the sulfur-poisoned cell has been described, but the recovery of the characteristics against the poisoning by carbon monoxide may be used, and the discharge from the cell is stopped in order to recover the characteristics of the cell. It is a technology that can be applied when making it.

Further, in the present embodiment, as the recovery treatment control of sulfur poisoning, the flow rate of hydrogen and air is increased by opening all the control valves 50C of the recovery-requiring cell Cc to promote the power generation in the recovery-requiring cell Cc. Although the potential was increased (step S31), for example, a circuit capable of supplying oxygen to the anode separator 41 and hydrogen to the cathode separator 42 was separately provided, and all the control valves 50C of the recovery cell Cc were closed first. After consuming hydrogen and oxygen in the anode separator 41 and the cathode separator 42, oxygen is supplied to the anode separator 41 and hydrogen is supplied to the cathode separator 42, respectively, so that the characteristics of the anode separator 41 and the cathode separator 42 are restored. May be good.

Further, as described above, first, all the control valves 50C of the recovery-required cell Cc are closed to consume the hydrogen and oxygen in the anode separator 41 and the cathode separator 42, and then oxygen is applied to the anode separator 41 and the cathode separator. By supplying hydrogen to each of the 42, it is possible to suppress the generation of a reverse current and the deterioration of the catalyst layer 43b of the membrane electrode assembly 43.
Further, in the present embodiment, the control mode has been described using each flow, but the order of these flows is an example, and the order may be changed to the extent that the present invention can be carried out.

1 Vehicle 13 Fuel cell system 21 Fuel cell 50C Control valve (recovery processing device) for cell requiring recovery
Control valve (operating device) of 50D operating cell
60C Cathode output switch for cell requiring recovery (recovery processing device)
Cathode output switch (operating device) of 60D operating cell
65C Anode output switch for cell requiring recovery (recovery processing device)
Anode output switch (operating device) of 65D operating cell
70 Voltage sensor (voltage detector)
81 Recovery-required cell setting unit (recovery-required cell selection unit)
82 Working cell setting unit (Operating cell selection unit)
85 Operation control unit 86 Recovery processing control unit Cc Recovery required cell Cd Operation cell

Claims (7)

A fuel cell system having a fuel cell containing a plurality of cells that generate electricity using fuel.
An operating device that operates at least one of the plurality of cells,
A recovery processing device that executes a recovery process for recovering the poisoned state to a normal state in at least one of the plurality of cells, and a recovery processing device.
A recovery-requiring cell selection unit that selects a recovery-requiring cell that is a cell that requires execution of the recovery processing among the plurality of cells, and a recovery-requiring cell selection unit.
An operating cell selection unit that selects an operating cell that is at least one cell other than the recovery-requiring cell among the plurality of cells.
A recovery processing control unit that controls the recovery processing device and executes the recovery processing in the recovery-required cell.
An operation control unit that controls the operation device to operate the operation cell,
Fuel cell system with. A voltage detection unit for detecting the voltage value of each of the plurality of cells is provided.
The fuel cell system according to claim 1, wherein the recovery-requiring cell selection unit selects a cell whose voltage value detected by the voltage detection unit is equal to or less than a predetermined value among the plurality of cells as the recovery-requiring cell. A storage unit for storing the last time of the recovery process of each of the plurality of cells is provided.
2. The fuel cell system described. The fuel cell system according to any one of claims 1 to 3, wherein the recovery processing control unit ends the recovery processing when a predetermined time elapses from the start of the recovery processing. A voltage detection unit for detecting the voltage value of each of the plurality of cells is provided.
The fuel cell system according to claim 4, wherein the recovery processing control unit changes the predetermined time according to the voltage value detected by the voltage detection unit. The fuel cell system according to any one of claims 1 to 5, wherein the operating cell selection unit selects the operating cell so that at least one of the recovery-requiring cells is sandwiched between the operating cells. A battery for storing electric power generated by the fuel cell is provided.
The fuel cell system according to any one of claims 1 to 6, wherein the fuel cell system outputs electric power through the battery.

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