JP2019129062A - Device and method for controlling fuel battery - Google Patents

Abstract

To suppress degradation of a fuel battery.SOLUTION: The present invention relates to a controller 2 for a fuel battery 1, which includes: an anode-side controller 2C for supplying a first reactant gas or a mixture gas to an anode; and a cathode-side controller 2D for supplying a mixture gas to a cathode. In a stop control time of stopping the fuel battery 1 by cutting the connection between the fuel battery 1 and an output circuit 3, the cathode-side controller 2D stops supply of the mixture gas and the anode-side controller 2c supplies the mixture gas instead of the first reactant gas to the anode at a predetermined supply rate when the cathode is filled with a non-reactant gas after the cathode-side controller 2D stops supplying the mixture gas.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device and a control method for a fuel cell that can be used as a power source for a vehicle or a household power source.

  In the past, a fuel cell vehicle (FCV; Fuel Cell Vehicle) has been developed that uses a fuel cell to generate electricity using the combustion reaction between hydrogen (hydrogen gas) and oxygen (air) and operates the motor using that power. Yes. Fuel cells are classified into various types such as polymer electrolyte fuel cells, molten carbonate fuel cells, and solid oxide fuel cells depending on the chemical reaction and the type of electrolyte. Above all, polymer electrolyte fuel cells (PEFCs) are capable of generating electricity at operating temperatures from normal temperature to 100 ° C. or less, and are expected to be used as power sources for vehicles and household power generators Has been.

  A polymer electrolyte fuel cell (fuel cell) has an anode through which hydrogen (hydrogen gas) flows, a cathode through which oxygen (air) flows, and an anode and a cathode inside a fuel cell stack provided inside. The hydrogen in the anode reacts with the catalyst layer to generate protons (hydrogen ions) and electrons, and the protons permeate the electrolyte medium, and the cathode is provided with the membrane electrode assembly (MEA; Membrane Electrode Assembly). The generated electrons are generated by being sent to an external output circuit while generating water by combining with the oxygen in the interior.

  By the way, since hydrogen used for power generation of a fuel cell is a flammable gas, it is not preferable to leave hydrogen in the anode while the fuel cell is stopped. Also, when the fuel cell is stopped (when power generation is stopped), if air remains in the cathode and hydrogen remains in the anode, oxygen contained in the air in the cathode and hydrogen in the anode combine to generate a potential. Make it happen. As a result, it is known that the catalyst and the catalyst support are oxidized and corroded, and consequently the performance of the fuel cell is deteriorated.

  In response to these problems, a fuel cell system has been proposed in which the supply of hydrogen to the anode is stopped, the air is supplied to the anode, and the hydrogen in the anode is replaced with air as a stop process when the fuel cell is stopped. (See, for example, Patent Document 1). In this system, by replacing hydrogen existing in the anode of the fuel cell with air, air is left in the anode and in the cathode in the power generation stop state. This prevents hydrogen from remaining in the fuel cell when power generation is stopped, and suppresses oxidation and corrosion of the catalyst and catalyst support due to the reaction of residual gas in the fuel cell, thereby suppressing deterioration in cell performance. Yes.

JP 2006-507647 gazette

  However, in the system of Patent Document 1 described above, when hydrogen in the anode is replaced with air as stop processing, air containing oxygen is present in the cathode, and air containing oxygen is present in the anode. And hydrogen coexist. Thus, when air containing oxygen is present in the cathode and both the air containing oxygen and hydrogen coexist in the anode, the cathode is at a high voltage, and the catalyst and catalyst support in the fuel cell are present. There is a problem of oxidative degradation of the body. That is, this state causes deterioration of the fuel cell.

  Further, in the system of Patent Document 1 described above, since air remains in the anode and the cathode at the start of the fuel cell, it is necessary to replace the air in the anode with hydrogen. There is air containing oxygen in the cathode, and both the air containing oxygen and hydrogen coexist in the anode. For this reason, also at the start of the fuel cell, the cathode has a high voltage as in the stop, causing oxidation deterioration of the catalyst and the catalyst support in the fuel cell, leading to deterioration of the fuel cell.

  The control device and control method of the fuel cell of the present invention have been devised in view of such problems, and one object thereof is to suppress the deterioration of the fuel cell. The present invention is not limited to this object, and it is an operation and effect derived from each configuration shown in the “embodiments to be described later”, and it is also possible to exert an operation and effect that can not be obtained by the prior art. Can be positioned as a purpose.

  (1) A control device of a fuel cell disclosed includes an anode, a cathode, and an electrolyte medium disposed between the anode and the cathode, and is connected to an output circuit, and the first reaction gas in the anode is A control device for a fuel cell that generates power by flowing and flowing a mixed gas containing a second reactive gas and a non-reactive gas in the cathode, and supplying the first reactive gas or the mixed gas to the anode An anode-side control unit; and a cathode-side control unit that supplies the mixed gas to the cathode.

  The cathode-side control unit stops the supply of the mixed gas at the time of stop control for stopping the fuel cell by cutting off the connection between the fuel cell and the output circuit, and the anode-side control unit When the cathode is filled with the non-reactive gas after the supply of the mixed gas by the side controller is stopped, the mixed gas is used instead of the first reactive gas, and the speed of the first reactive gas supplied to the anode during power generation The anode is fed at a predetermined feed rate which is lower than that of the anode.

  (2) The control device preferably includes an acquisition unit that acquires the temperature of the fuel cell, and a cooling control unit that controls supply of a cooling medium to the fuel cell. Further, it is preferable that the cooling control unit supplies the cooling medium at least until the temperature becomes equal to or lower than a predetermined temperature during the stop control.

(3) It is preferable that the cathode side control unit stops the supply of the mixed gas when the temperature becomes equal to or less than the predetermined temperature.
(4) Alternatively, it is preferable that the cooling control unit supply the cooling medium until the temperature becomes equal to or lower than a predetermined temperature after the supply control of the mixed gas by the anode control unit is stopped.

  (5) In the start-up control for starting up the fuel cell, the control device supplies the first reactive gas to the anode and supplies the non-reactive gas in the anode to the first. Preferably, the cathode side control unit supplies the mixed gas to the cathode when the anode is filled with the first reaction gas.

  (6) In the control device, the fuel cell is provided with a voltage sensor that detects a voltage of the fuel cell, and the anode-side control unit is configured to control the mixed gas by the cathode control unit during the stop control. It is preferable to determine that the non-reactive gas is filled in the cathode when the voltage after supply stoppage is less than a predetermined value.

  (7) A control method of a fuel cell according to the disclosure includes an anode, a cathode, and an electrolyte medium disposed between the anode and the cathode, and is connected to an output circuit, and the first reaction gas in the anode is A fuel cell control method for generating power by flowing and flowing a mixed gas containing a second reactive gas and a non-reactive gas in the cathode, wherein the connection between the fuel cell and the output circuit is cut off, and A first step of stopping the supply of the mixed gas to the cathode during stop control for stopping the fuel cell; and after the first step, when the cathode is filled with the non-reactive gas, the first to the anode The second step of stopping the supply of the reaction gas, and after the second step, the mixed gas is supplied to the anode at the time of power generation instead of the first reaction gas. And a third step of supplying to said anode at a predetermined feed speed is slower than the speed of the first reaction gas.

  (8) The control method preferably includes a cooling step of supplying cooling water to the fuel cell at least until the temperature of the fuel cell falls below a predetermined temperature at the time of the stop control.

(9) In the first step, preferably, the supply is stopped when the temperature of the fuel cell becomes equal to or lower than the predetermined temperature by performing the cooling step.
(10) Alternatively, the cooling step is preferably performed after the third step.

  (11) In the control method, the first reactive gas is supplied to the anode during start control for starting the fuel cell in which the stop control is performed, and the non-reactive gas in the anode is converted into the first reaction. It is preferable to supply the mixed gas to the cathode after gas substitution.

  According to the disclosed fuel cell control device and control method, as fuel cell stop control, air containing oxygen in the cathode is replaced with nitrogen (air in which oxygen has been consumed), and then supplied to the anode at a predetermined supply rate. By supplying air, the anode is replaced with nitrogen (air in which oxygen has been consumed). As a result, during stop control of the fuel cell, oxygen-containing air is present in the cathode and both oxygen-containing air and hydrogen do not co-exist in the anode. Can be suppressed. As a result, it is possible to suppress the deterioration of the elements constituting the fuel cell.

  Further, according to the disclosed fuel cell control device and control method, when the fuel cell is completely stopped, nitrogen (air in which oxygen is consumed) remains in the anode and the cathode. This can prevent the generation of a potential in the fuel cell, and oxygen does not remain in the anode and the cathode, so the elements of the fuel cell are not oxidized and degraded. Therefore, it is possible to suppress the deterioration of the elements of the fuel cell.

It is the schematic which shows the control apparatus which concerns on embodiment with the structure of a fuel cell. It is sectional drawing which shows the outline of the fuel cell stack which the fuel cell of FIG. 1 has. 3 is a chart illustrating the composition of gas present in the anode and cathode of the fuel cell stack of FIG. 2 during stop control of the fuel cell of FIG. 1. 3 is a chart illustrating the composition of gases present in the anode and cathode of the fuel cell stack of FIG. 2 during start-up control of the fuel cell of FIG. 1.

  Hereinafter, a control device and a control method of a fuel cell as an embodiment will be described with reference to the drawings. The fuel cell controlled by the control device of the present embodiment is a power generation system applied to, for example, an electric vehicle, a hybrid vehicle, and a household electric product. The type of fuel cell is a polymer electrolyte fuel cell (PEFC). However, the fuel cell in this case is a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), a phosphoric acid fuel cell (PAFC). ), An alkaline electrolyte fuel cell (AFC) can be used.

  The embodiments shown below are merely illustrative, and there is no intention to exclude the application of various modifications and techniques that are not specified in the following embodiments. Each structure of this embodiment can be variously modified and implemented in the range which does not deviate from those meaning. Also, they can be selected as needed or can be combined as appropriate.

[1. Device configuration]
[1-1. overall structure]
FIG. 1 is a schematic view showing a control device 2 according to the present embodiment together with the configuration of a fuel cell 1. As shown in FIG. 1, the fuel cell 1 includes a hydrogen supply device 7, an air supply device 8, flow paths 31 to 35 and valves 42 to 44 for supplying gas to a fuel cell stack 10 that is a power generation element, It has flow paths 36 and 37 and valves 45 and 46 for discharging the gas flowing out of the battery stack 10 to the outside. The fuel cell 1 of the present embodiment is provided with a hydrogen reservoir 11, flow paths 38 and 39, and valves 47 to 49 for collecting and circulating hydrogen gas as fuel out of the outflowed gas.

  Further, in the fuel cell 1, an output terminal 3A and an output switch 3B for extracting electric power generated by the fuel cell stack 10, and a discharge terminal 4A and a discharge switch arranged in parallel to the output terminal 3A and the output switch 3B. And 4B. The fuel cell 1 further includes a cooling device 9 and a flow path 40 for cooling the fuel cell stack 10. The fuel cell stack 10 further includes a temperature sensor 15 for detecting the temperature of the fuel cell stack 10 and a voltage sensor 16 for detecting the voltage of each cell of the fuel cell stack 10 (hereinafter referred to as cell voltage). The control device 2 controls the operating states of the devices 7 to 9 and 11 provided in the fuel cell 1, the open / close states of the valves 42 to 49, and the connection / disconnection states of the switches 3 </ b> B and 4 </ b> B. Further, the information detected by each of the sensors 15 and 16 is transmitted to the control device 2.

  As shown in FIG. 2, the fuel cell stack 10 includes an anode 12 through which hydrogen gas (first reaction gas, hereinafter simply referred to as “hydrogen”) flows, oxygen (second reaction gas), and nitrogen (non-reaction gas). ) Containing air (mixed gas) and an electrolyte medium disposed between the anode 12 and the cathode 13. Hydrogen in the anode 12 reacts with the catalyst layer to generate protons (hydrogen ions) and electrons, and the protons pass through the electrolyte medium and combine with oxygen in the cathode 13 to generate water. Electricity is generated by the electrons being sent to the output circuit 3.

  As shown in FIG. 1, the output terminal 3 A is a terminal connected to the output circuit 3 outside the fuel cell 1, and transmits the power generated by the fuel cell 1 to the output circuit 3. The output switch 3B is a switch that connects and disconnects the fuel cell 1 and the output circuit 3 and is disposed in series with the output terminal 3A. The discharge terminal 4A is a terminal connected to the discharge circuit 4 arranged in parallel to the output circuit 3 with respect to the fuel cell 1 outside the fuel cell 1, and the fuel cell 1 is not connected to the output circuit 3. When the fuel cell 1 is connected, the power accumulated in the fuel cell 1 is transmitted to the discharge circuit 4. The discharge switch 4B is a switch that connects and disconnects the fuel cell 1 and the discharge circuit 4 and is disposed in series with the discharge terminal 4B.

  The hydrogen supply device 7 is a device for supplying hydrogen to the fuel cell stack 10, and includes, for example, a tank for compressing and storing hydrogen, and a pump (not shown) for delivering the hydrogen stored in the tank. The air supply device 8 is a device for supplying air to the fuel cell stack 10, and is constituted by a known blower or the like that takes in air from the outside of the fuel cell 1 and blows the air. The operation states of the hydrogen supply device 7 and the air supply device 8 are controlled by an anode side control unit 2C described later or a cathode side control unit 2D described later.

  Connected to each of the hydrogen supply device 7 and the air supply device 8 are a hydrogen supply device 31, hydrogen supplied from the air supply device 8, a hydrogen supply passage 31 for circulating air, and an air supply passage 32. Between the hydrogen supply path 31 and the anode 12 of the fuel cell stack 10, an anode-side supply path 33 that connects these is connected. The anode side supply path 33 is provided with a valve 42 for continuing or stopping the supply of gas to the anode 12. The open / close state of the valve 42 is controlled by the anode-side controller 2C.

  Between the air supply path 32 and the cathode 13 of the fuel cell stack 10, a cathode side supply path 34 that connects these is connected. The cathode side supply passage 34 is provided with a valve 43 for continuing or stopping supply of gas to the cathode 13. The open / close state of the valve 43 is controlled by the cathode side control unit 2D.

  The fuel cell 1 of the present embodiment is provided with a communication passage 35 for supplying the air sent to the air supply passage 32 to the anode 12 via the anode side supply passage 33. The upstream end of the communication path 35 is connected to the air supply path 32, and the downstream end is connected to the hydrogen supply path 31. The communication passage 35 is provided with a valve 44 which makes the gas flow direction one way, and only the air supplied from the air supply passage 32 flows. That is, the valve 44 is a check valve. In the closed state of the valve 44, the flow of air is shut off. The open / close state of the valve 44 (the gas flow state in the communication passage 35) is controlled by the anode-side control unit 2C or the cathode-side control unit 2D.

  More specifically, when the valve 44 of the communication passage 35 is closed, the hydrogen supplied from the hydrogen supply device 7 is supplied to the anode 12 of the fuel cell stack 10 via the hydrogen supply passage 31 and the anode side supply passage 33. Is done. Further, the air supplied from the air supply device 8 when the valve 44 is closed is supplied to the cathode 13 of the fuel cell stack 10 via the air supply passage 32 and the cathode side supply passage 34. On the other hand, when the valve 44 of the communication passage 35 is opened, part of the air sent from the air supply device 8 passes through the air supply passage 32, the connection passage 35 and the anode side supply passage 33 to form the fuel cell stack 10. To the anode 12.

  The anode side discharge path 36 and the cathode side discharge path 37 connected to the anode 12 and the cathode 13 of the fuel cell stack 10 respectively transmit the gas delivered from the anode 12 and the cathode 13 of the fuel cell stack 10 to the outside of the fuel cell 1 Flow path to In each of the anode side discharge path 36 and the cathode side discharge path 37, valves 45 and 46 for switching whether or not to discharge the gas sent from the anode 12 and the cathode 13 to the outside of the fuel cell 1 are interposed. The The open / closed state of the valves 45 and 46 (the state of gas discharge to the outside) is controlled by the anode-side control unit 2C and the cathode-side control unit 2D.

  One end (upstream end) of a hydrogen recirculation path 38 for recirculating hydrogen flowing through the anode 12 of the fuel cell stack 10 is connected to the upstream side of the valve 45 of the anode side discharge path 36. The other end (downstream end) of the hydrogen recirculation path 38 is connected to the hydrogen supply path 31. A valve 47 for blocking the hydrogen flowing into the hydrogen recirculation path 38 from the anode side discharge path 36 from flowing into the hydrogen supply path 31 at the downstream portion of the hydrogen recirculation path 38 (immediately upstream of the downstream end). Is installed. Further, a valve 49 for blocking the outflow of hydrogen from the hydrogen recycle passage 38 to the anode side discharge passage 36 is interposed in the upstream part (directly downstream part of the upstream end) of the hydrogen recycle passage 38. The open / close state of the valves 47 and 49 is controlled by the anode-side controller 2C.

  One end of the reservoir connecting passage 39 is connected to a portion of the hydrogen recirculation passage 38 downstream of the valve 49 and upstream of the valve 47. The other end of the reservoir connecting path 39 is connected to the hydrogen reservoir 11. The hydrogen storage unit 11 temporarily suspends the hydrogen sent from the anode 12 when the fuel cell 1 is shut off by stopping the connection between the fuel cell 1 and the output circuit 3 (when the power generation of the fuel cell stack 10 is stopped). And has a function of releasing hydrogen stored when the fuel cell stack 10 is activated. A valve 48 that continues or stops the circulation of the gas in the flow path 39 is interposed in the storage section connection path 39. The gas release state of the reservoir connecting passage 39 and the open / close state of the valve 48 are controlled by the anode-side control unit 2C. Further, the capacity of the gas (hydrogen) in the hydrogen storage unit 11 is detected by the anode-side control unit 2C or the cathode control unit 2D.

  The cooling device 9 is a device for circulating (circulating) a cooling medium (hereinafter referred to as cooling water) for cooling the fuel cell stack 10 in the cooling water circulation path 40 connected to the fuel cell stack 10. And a tank for storing the cooling water, a pump for circulating the cooling water, and a radiator for radiating the cooling water (both not shown). The fuel cell stack 10 is provided with a cooling water flow passage 14 (see FIG. 2), which will be described later, in communication with the cooling water circulation passage 40. The cooling water supplied from the cooling device 9 cools the fuel cell stack 10 by returning to the cooling device 9 via the cooling water circulation passage 40 and the cooling water flow passage 14 of the fuel cell stack 10. The operating state of the cooling device 9 is controlled by a cooling control unit 2B described later.

[1-2. Configuration of fuel cell stack]
FIG. 2 is a cross-sectional view schematically showing the fuel cell stack 10.
As shown in FIG. 2, the fuel cell stack 10 includes an anode separator 21, a cathode separator 22, a gasket 23 in which a membrane electrode assembly 24 is interposed, and a current collector plate 25. The fuel cell stack 10 of the present embodiment has a stack assembly structure in which a plurality of anode separators 21, a plurality of cathode separators 22, and a plurality of gaskets 23 having a membrane electrode assembly 24 interposed therebetween are stacked in the thickness direction. Have FIG. 2 illustrates a fuel cell stack 10 in which an anode separator 21, a gasket 23, and a cathode separator 22 are arranged in this order between current collector plates 25 arranged at both ends in the plate thickness direction. .

  Here, a “cell” is configured by disposing a single gasket 23 with a membrane electrode assembly 24 interposed between one anode separator 21 and one cathode separator 22. Call. That is, it can be said that the fuel cell stack 10 is configured by stacking a plurality of cells between a pair of current collecting plates 25 arranged at both ends in the plate thickness direction.

  The current collectors 25 disposed at both ends of the fuel cell stack 10 are conductive parts formed of copper or stainless steel. The current collecting plate 25 is provided with a terminal for taking out the generated power of the fuel cell stack 10, for example, and is connected to a circuit provided with the output terminal 3A, the output switch 3B, the discharge terminal 4A, and the discharge switch 4B.

The gasket 23 is a thin plate-like elastic member formed of rubber, synthetic resin or the like, and has a sealing function to prevent leakage of hydrogen, air, cooling water or the like.
The membrane electrode assembly 24 is composed of an electrolyte medium (not shown), an anode (not shown) and a cathode (not shown). The anode electrode and the cathode electrode are formed, for example, by uniformly applying a diffusion layer (GDL; Gas Diffusion Layer) made of carbon paper or the like and porous carbon particles having a platinum alloy supported on the surface on the surface of the diffusion layer. And a catalyst layer. The electrolyte medium is, for example, a solid polymer membrane such as a proton exchange membrane or an anion exchange membrane. The membrane electrode assembly 24 has a structure in which the anode electrode is disposed on one side of the electrolyte medium, and the cathode electrode is disposed on the opposite side.

  The anode separator 21 and the cathode separator 22 are both conductive separators. Grooves are formed on each surface of the anode separator 21 and the cathode separator 22 that contact the membrane electrode assembly 24, and these grooves form the anode 12 and the cathode 13. Grooves are also formed on each surface of the anode separator 21 and the cathode separator 22 on the side not in contact with the membrane electrode assembly 24, and these grooves form the cooling water passage 14. The grooves forming the cooling water passages 14 provided in the anode separator 21 and the cathode separator 22 adjacent to each other are formed to face each other. Thereby, since the flow paths can be overlapped, it is possible to double the flow path area of the cooling water.

  The anode 12 is formed by communication between a groove provided in the anode separator 21 and a hole formed in each of the anode separator 21, the cathode separator 22, the gasket 23, and the current collector plate 25. The gas supplied from the anode side supply path 33 circulates in the anode 12 (flow path) configured as described above.

  Similarly, the cathode 13 is formed by communication between a groove provided in the cathode separator 22 and holes formed in each of the anode separator 21, the cathode separator 22, the gasket 23, and the current collector plate 25. The gas supplied from the cathode side supply path 34 flows through the cathode 13 (flow path) configured in this manner.

The cooling water passage 14 communicates with grooves provided in each of the anode separator 21 and the cathode separator 22 and holes formed in each of the anode separator 21, the cathode separator 22, the gasket 23 and the current collector plate 25. Formed by. The cooling water supplied from the cooling device 9 flows through the cooling water passage 14 configured as described above.
The anode 12, the cathode 13 and the cooling water passage 14 are all independent flow paths and do not intersect with each other in the fuel cell stack 10.

[2. Control configuration]
The control device 2 of the present embodiment performs control for suppressing deterioration of the fuel cell 1 when the connection between the fuel cell 1 and the output circuit 3 is cut off and the fuel cell 1 is stopped. The control performed at this time is called “stop control”. Stop control is performed, for example, when the control device 2 receives a signal (stop signal) in which an ignition switch (not shown) of a vehicle equipped with the fuel cell 1 of the present embodiment is turned off (in a household electric appliance or the like). , And when the control device 2 receives a signal that the main power is turned off.

  Further, even when the fuel cell 1 is started after the stop control is performed, the control device 2 of the present embodiment performs the control for suppressing the deterioration of the fuel cell 1. The control performed at this time is called "startup control". For example, in the case where the control device 2 receives a signal (start signal) in which an ignition switch (not shown) of a vehicle equipped with the fuel cell 1 of the present embodiment is turned on (IG-ON) is received (in a household electrical appliance or the like) For example, when the control device 2 receives a signal indicating that the main power supply is turned on).

  As shown in FIG. 1, the control device 2 is provided with an acquisition unit 2A, a cooling control unit 2B, an anode side control unit 2C, and a cathode side control unit 2D as elements for carrying out the stop control and start control described above. It is done. Each of these elements may be realized by an electronic circuit (hardware), may be programmed as software, or some of these functions may be provided as hardware and the other part as software. It may be something.

[2-1. Acquisition Department]
The acquiring unit 2A acquires the temperature of the fuel cell stack 10 as the temperature of the fuel cell 1. The temperature of the fuel cell stack 10 (hereinafter referred to as the battery temperature) is detected by, for example, a temperature sensor 15 provided in the fuel cell stack 10. Acquisition unit 2A acquires the battery temperature transmitted from temperature sensor 15, and transmits the acquired battery temperature to cooling control unit 2B. In addition, the acquisition unit 2A of the present embodiment acquires the cell temperature when the connection between the fuel cell 1 and the output circuit 3 is interrupted to stop the fuel cell 1 (that is, during stop control), and the cell temperature is It is determined whether the temperature has fallen below a predetermined temperature. If it is determined that the battery temperature has become equal to or lower than the predetermined temperature, the determination result is transmitted to the cathode side control unit 2D.

  When the temperature of the fuel cell stack 10 decreases, water generated by a chemical reaction in the fuel cell stack 10 condenses, and the condensed water remains in the fuel cell stack 10. The remaining condensed water in the fuel cell stack 10 can suppress the deterioration of each element (catalyst, catalyst support, etc.) that constitutes the fuel cell stack 10 at the time of power generation stop. For this reason, it is preferable that the “predetermined temperature” is set to a temperature at which deterioration of elements constituting the fuel cell stack 10 can be suppressed as much as possible. For example, the predetermined temperature is set in advance according to the material and characteristics of the catalyst constituting the fuel cell 1.

[2-2. Cooling control unit]
The cooling control unit 2 </ b> B controls the supply of cooling water to the fuel cell stack 10. The cooling control unit 2 B supplies cooling water to the fuel cell stack 10 by controlling the operating state of the cooling device 9.

  When the fuel cell 1 is caused to generate power, the cooling control unit 2B of the present embodiment controls the flow rate of the cooling water sent from the cooling device 9 to keep the fuel cell stack 10 at an appropriate temperature. More specifically, the cooling control unit 2B controls the cooling device 9 based on the battery temperature transmitted from the acquiring unit 2A while the fuel cell 1 is generating electricity. For example, when the temperature of the fuel cell stack 10 is too high, the cooling device 9 is controlled to increase the flow rate of the cooling water sent from the cooling device 9. When the temperature of the fuel cell stack 10 is too low, the cooling device 9 is controlled to reduce the flow rate of the cooling water.

  Further, when the power generation of the fuel cell 1 is stopped (that is, at the time of stop control), the cooling control unit 2B of the present embodiment supplies cooling water until at least the battery temperature becomes equal to or lower than the above-mentioned predetermined temperature. The cooling control unit 2B may stop the supply of the cooling water when the battery temperature becomes equal to or lower than the predetermined temperature, or may reduce the flow rate while continuing the supply of the cooling water.

[2-3. Anode control unit]
The anode side control unit 2C supplies hydrogen (first reaction gas) or air (mixed gas) to the anode 12, and the respective operating states of the hydrogen supply device 7 and the air supply device 8 and the valves 42, 44, 45 and 47 to 49 are controlled.

  Specifically, the anode-side control unit 2C operates the hydrogen supply device 7 when the fuel cell 1 is caused to generate power. Further, the valve 42 of the anode side supply passage 33 and the valve 47 and the valve 49 of the hydrogen recirculation passage 38 are opened, and the valve 44 of the communication passage 35, the valve 45 of the anode side discharge passage 36 and the reservoir connection passage 39 And the valve 48 is closed. Thus, hydrogen flows in the anode 12. The anode-side control unit 2C opens the valve 45 of the anode-side discharge passage 36 as needed, and discharges the impurities contained in the hydrogen discharged from the anode 12 to the outside of the fuel cell 1.

  When stopping the fuel cell 1 (during stop control), the anode-side control unit 2C stops the supply of air to the cathode 13 and then charges the air instead of hydrogen when the cathode 13 is filled with nitrogen. 12 is supplied. The anode side control unit 2C of the present embodiment acquires the cell voltage from the voltage sensor 16 and determines whether the cathode 13 is filled with nitrogen depending on whether the cell voltage is less than a predetermined value. If the cell voltage is equal to or higher than a predetermined value, the supply of hydrogen to the anode 12 is continued. On the other hand, when the cell voltage becomes lower than the predetermined value, it is determined that the cathode 13 is filled with nitrogen, and the supply of hydrogen to the anode 12 is stopped, and air is supplied to the anode 12 instead of hydrogen.

  In the stop control of the present embodiment, as described above, the supply of air to the cathode 13 is stopped before the supply of hydrogen to the anode 12 is stopped. As described above, when the supply of air to the cathode 13 is stopped and the supply of hydrogen to the anode 12 is continued, oxygen contained in the air in the cathode 13 reacts with the hydrogen in the anode 12 and gradually. As it is consumed, the cell voltage decreases as the oxygen in the cathode 13 decreases. That is, since the cell voltage and the proportion of oxygen in the cathode 13 are in a proportional relationship, the proportion of nitrogen in the cathode 13 (whether or not it is full) can be determined based on the cell voltage.

The control content implemented by the anode-side control unit 2C after the cell voltage becomes lower than the predetermined value will be described in detail.
The anode side control unit 2C stops the hydrogen supply device 7 when the cell voltage becomes lower than a predetermined value, and starts the air supply device 8 stopped by the cathode side control unit 2D described later. Further, the anode-side control unit 2C opens the valve 44 of the communication path 35 and the valve 48 of the storage unit connection path 39, and closes the valve 47 of the hydrogen recirculation path 38. Then, when supplying air to the anode 12 instead of hydrogen, the anode-side control unit 2C controls the air supply device 8 so that the supply speed becomes a predetermined supply speed. Here, the predetermined supply rate is lower than the rate of hydrogen (hydrogen supply rate) supplied to the anode 12 at the time of power generation. That is, the gas supply rate to the anode 12 is slower for the air supply rate (predetermined supply rate) during stop control than for the hydrogen supply rate during power generation.

  The predetermined supply rate of the present embodiment disappears when oxygen contained in the air in the anode 12 reacts with hydrogen existing in the anode 12 while air is supplied from the air supply device 8 to the anode 12. It is considered to be a speed to gain. The predetermined supply rate is preset according to the material and characteristics of the catalyst that constitutes the fuel cell 1, the structure of the anode 12, and the like. The predetermined supply speed may be provided as a variable value that varies depending on the temperature of the fuel cell stack 10 or the like.

  The anode-side control unit 2C also acquires the amount of gas (hydrogen) stored in the hydrogen storage unit 11 when air is supplied to the anode 12 instead of hydrogen. When the anode side control unit 2C of the present embodiment detects that the amount of gas stored in the hydrogen storage unit 11 becomes equal to the capacity of the anode 12, it determines that the anode 12 is filled with nitrogen, and the anode 12 Turn off the air supply to Specifically, the air supply device 8 is stopped, and the valve 42 of the anode side supply passage 33, the valve 44 of the communication passage 35, the valve 48 of the reservoir connection passage 39 and the valve 49 of the hydrogen recirculation passage 38 are closed. I speak. In this way, the anode 12 and the cathode 13 are filled with nitrogen.

  When the fuel cell 1 that has been subjected to stop control is started (that is, during start-up control), the anode-side control unit 2C needs to supply hydrogen to the anode 12 and replace nitrogen in the anode 12 with hydrogen. is there. The anode side control unit 2C of the present embodiment supplies hydrogen from the hydrogen supply device 7 to the anode 12 after all the gas stored in the hydrogen storage unit 11 is sent out of the hydrogen storage unit 11.

  Specifically, the anode side control unit 2C opens the valve 42 of the anode side supply path 33, the valve 45 of the anode side discharge path 36, the valve 47 of the hydrogen recirculation path 38, and the valve 48 of the storage section connection path 39. The hydrogen storage unit 11 is controlled so as to discharge the gas (hydrogen) stored in the hydrogen storage unit 11 while closing the valve 49 of the hydrogen recirculation passage 38 while controlling the valve. Thereafter, the anode-side control unit 2C detects the remaining amount of gas in the hydrogen storage unit 11, and when detecting that all the gas in the hydrogen storage unit 11 has been discharged, the anode-side supply path 33 and the hydrogen While the valve 47 of the recirculation passage 38 is opened, the valve 45 of the anode side exhaust passage 36 and the valve 48 of the reservoir connection passage 39 are closed, and the valve 49 of the hydrogen recirculation passage 38 is opened. The hydrogen supply device 7 is activated.

[2-4. Cathode side control unit]
The cathode-side control unit 2D supplies air (mixed gas) to the cathode 13 and controls the operating state of the air supply device 8 and the open / close states of the valves 43 and 46.

  More specifically, when the fuel cell 1 is to generate power, the cathode side control unit 2D operates the air supply device 8 and operates the valve 43 of the cathode side supply passage 34 and the valve 46 of the cathode side discharge passage 37. Open the valve. Thereby, air flows in the cathode 13.

  The cathode-side control unit 2D stops the supply of air to the cathode 13 when stopping the fuel cell 1 (during stop control). The cathode side control unit 2D of the present embodiment obtains the battery temperature from the temperature sensor 15, and determines whether the battery temperature is equal to or less than the above-described predetermined temperature. If the battery temperature is equal to or higher than the predetermined temperature, the supply of air to the cathode 13 is continued. On the other hand, when the battery temperature falls below a predetermined temperature, the supply of air to the cathode 13 is stopped.

  Specifically, the cathode-side control unit 2D stops the air supply device 8 when the determination result that the battery temperature is equal to or lower than the predetermined temperature is transmitted from the acquisition unit 2A, and the cathode-side control unit 2D The valve 46 of the cathode side discharge passage 37 is closed. Note that when the supply of air to the cathode 13 is stopped, the supply of hydrogen to the anode 12 is continued, whereby the cell voltage starts to decrease. That is, the timing at which the supply of air to the cathode 13 is stopped is before the timing at which the supply of hydrogen is stopped by the anode-side control unit 2C.

When starting the fuel cell 1 that has been subjected to stop control (during start-up control), the cathode-side control unit 2D supplies air to the cathode 13 when the anode 12 is filled with hydrogen.
Specifically, when the cathode side control unit 2D detects the remaining amount of gas in the hydrogen storage unit 11 and detects that all the gas in the hydrogen storage unit 11 is discharged, the anode 12 is filled with hydrogen. The valve 43 of the cathode side supply path 34 and the valve 46 of the cathode side discharge path 37 are opened and the air supply device 8 is activated to supply air to the cathode 13.

[3. Operation of fuel cell]
[3-1. Fuel Cell Power Generation Method]
When the fuel cell 1 described above is to generate power, the anode side control unit 2C operates the hydrogen supply device 7, and at the same time, the valve 42 of the anode side supply passage 33, the valve 47 of the hydrogen recirculation passage 38 and the valve 49 The valve is opened, and the valve 44 of the communication passage 35, the valve 45 of the anode side discharge passage 36, and the valve 48 of the reservoir connection passage 39 are closed. Further, the cathode side control unit 2D operates the air supply device 8 and opens the valve 43 of the cathode side supply path 34 and the valve 46 of the cathode side discharge path 37. Furthermore, the control device 2 connects the fuel cell 1 and the output circuit 3 by setting the output switch 3A in the connection state.

Thus, the fuel cell 1 generates electric power by flowing hydrogen through the anode 12 and flowing air through the cathode 13 in a state of being connected to the output circuit 3.
The hydrogen flowing in the anode 12 reacts with the catalyst layer constituting the anode electrode of the membrane electrode assembly 24 to generate protons (hydrogen ions) and electrons. The generated protons permeate the electrolyte medium of the membrane electrode assembly 24 and combine with oxygen flowing in the cathode 13 to form water. On the other hand, the generated electrons are sent to the output circuit 3. Thus, the fuel cell 1 generates power.
Further, at the time of power generation of the fuel cell 1, the cooling control unit 2B controls the flow rate of the cooling water sent from the cooling device 9 according to the battery temperature transmitted from the acquisition unit 2A.

[3-2. How to stop the fuel cell]
Among the control methods of the fuel cell 1 according to the present embodiment, a stop method will be described with reference to FIG. FIG. 3 is a chart showing the composition of the gas present in the anode 12 and the cathode 13 of the fuel cell stack 10 shown in FIG. 2 at the time of stopping control of the fuel cell 1. The white arrows in FIG. 3 indicate the state in which hydrogen is supplied, and the black arrows in FIG. 3 indicate the state in which air is supplied.

When the control device 2 receives the stop signal, the control device 2 disconnects the output switch 3B, and disconnects the connection between the output circuit 3 and the fuel cell 1 by setting the discharge switch 4B to the connection state. And the fuel cell 1 are connected.
In this state, the supply of hydrogen, air and cooling water to the fuel cell stack 10 is continued. That is, as indicated by (3-1) in FIG. 3, hydrogen is supplied to the anode 12, air is supplied to the cathode 13, and cooling water is continuously supplied to the cooling water passage 14.

  In this state, the acquisition unit 2 </ b> A acquires the temperature (cell temperature) of the fuel cell stack 10. The cooling control unit 2B continues to supply the cooling water until the acquiring unit 2A acquires that the battery temperature is equal to or lower than the predetermined temperature (cooling step).

  When the acquiring unit 2A acquires that the battery temperature has become equal to or lower than the predetermined temperature, the cathode side control unit 2D stops the supply of air to the cathode 13 as shown in (3-II) in FIG. 1 step). Specifically, the cathode side control unit 2D stops the air supply device 8 and closes the valve 43 of the cathode side supply path 34 and the valve 46 of the cathode side discharge path 37 to block the air flow. As a result, the supply of air to the cathode 13 is stopped, and the cathode 13 is sealed due to the closing of the inlet and outlet valves 43 and 37.

  In the state where the supply of air to the cathode 13 is stopped, the supply of hydrogen to the anode 12 is continued. For this reason, oxygen contained in air present in the cathode 13 reacts with hydrogen flowing in the anode 12 to be consumed, and the cathode 13 is filled with air from which oxygen has disappeared, that is, nitrogen. On the other hand, since the cathode 13 is in a sealed state, a pressure difference is generated between the cathode 13 and the anode 12 due to the disappearance of oxygen in the cathode 13, and a part of the hydrogen flowing through the anode 12 permeates into the cathode 13. To do. For this reason, as shown by (3-III) in FIG. 3, nitrogen (air in which oxygen has disappeared) and a trace amount of hydrogen remain in the cathode 13.

  In the above state (3-III), since the oxygen contained in the air in the cathode 13 reacts with the hydrogen in the anode 12 and is gradually consumed, the cell voltage decreases as the oxygen in the cathode 13 decreases. To do. In this state, since the discharge circuit 4 and the fuel cell 1 are in a connected state, the chemical reaction in the fuel cell 1 is further promoted. That is, when the discharge circuit 4 actively takes out the electric power from the fuel cell 1, oxygen present in the cathode 13 is further consumed.

  After the supply of air to the cathode 13 is stopped, when the cathode 13 is filled with nitrogen (non-reactive gas), the anode-side control unit 2C stops the supply of hydrogen to the anode 12 (second step). When the cell voltage after stopping the supply of air to the cathode 13 becomes less than a predetermined value, the anode-side control unit 2C of the present embodiment determines that the cathode 13 is filled with nitrogen and stops the hydrogen supply device 7. Supply of hydrogen to the anode 12 is stopped.

  Thereafter, the anode-side control unit 2C supplies air to the anode 12 in place of hydrogen (third step). At this time, the anode side control unit 2C supplies air to the anode 12 at a predetermined supply rate which is lower than the supply rate of hydrogen supplied to the anode 12 at the time of power generation.

  Specifically, the anode side control unit 2C opens the valve 44 provided in the communication passage 35 and the valve 48 of the storage unit communication passage 39 and closes the valve 47 provided in the hydrogen recirculation passage 38. Turn on the air supply device 8. Thus, the air flowing out of the air supply device 8 is supplied to the anode 12 via the air supply passage 32, the communication passage 35, and the anode side supply passage 33 in this order. Further, the anode side control unit 2C controls the air supply device 8 so as to supply air at the above-described predetermined supply rate.

  More specifically, as indicated by (3-IV) in FIG. 3, the proportion of air in the anode 12 increases as air is supplied to the anode 12 at a predetermined supply rate. The speed of the air supplied to the anode 12 is supplied more slowly than the supply speed of hydrogen supplied to the anode 12 during power generation. That is, while air is supplied from the air supply device 8 to the anode 12, the speed at which oxygen contained in the air in the anode 12 can be lost by reacting with hydrogen present in the anode 12 (predetermined supply speed). Then, air is supplied to the anode 12.

  Therefore, as indicated by (3-IV ′) in FIG. 3, oxygen in the air supplied to the anode 12 reacts with hydrogen present in the anode 12 while air flows into the anode 12. As a result, hydrogen and air from which oxygen has disappeared (i.e., nitrogen) are present at the anode 12. In this way, hydrogen is replaced with nitrogen by continuing to supply air to the anode 12 at a predetermined supply rate, and as shown by (3-V) in FIG. Full of nitrogen. Note that a small amount of hydrogen may remain in the state of (3-V). That is, “full of nitrogen” as used herein does not only mean that all the gas (100%) present in the anode 12 is nitrogen, but a state in which negligible hydrogen is included. including.

  Further, as air is supplied at a predetermined supply rate, hydrogen present in the anode 12 is sent out to the anode side exhaust passage 36 in a form of being pushed out by the supplied air. The hydrogen sent to the anode-side exhaust passage 36 is stored in the hydrogen storage unit 11 via the hydrogen recirculation passage 38 and the storage unit connection passage 39.

  When the volume of the gas stored in the hydrogen storage unit 11 becomes equal to the volume of the anode 12, the anode-side control unit 2C determines that the anode 12 is filled with nitrogen, and stops the supply of air to the anode 12. That is, the air supply device 8 is stopped, and the valve 42 of the anode side supply path 33, the valve 44 of the communication path 35, the valve 48 of the reservoir connection path 39, and the valve 49 of the hydrogen recirculation path 38 are closed. Thus, the fuel cell 1 completely stops in a state where the anode 12 and the cathode 13 are filled with nitrogen.

[3-3. Starting method of fuel cell]
The control method of the fuel cell 1 according to the present embodiment will be described with reference to FIG. FIG. 4 is a chart showing the composition of the gas present in the anode 12 and the cathode 13 of the fuel cell stack 10 shown in FIG. 2 during the start-up control of the fuel cell 1 in which the stop control is performed. The white and black arrows in FIG. 4 indicate the same states as the arrows in FIG.

As indicated by (4-I) in FIG. 4, when the control device 2 receives the start signal, the fuel cell 1 is in a state after the stop control is completed, so that the anode 12 and the cathode 13 have a slight amount of nitrogen and a small amount. Of hydrogen is present.
When the controller 2 receives the start signal, the anode controller 2C supplies hydrogen to the anode 12 to replace the nitrogen in the anode 12 with hydrogen, as indicated by (4-II) in FIG. 4. Specifically, the anode side control unit 2C opens the valve 42 of the anode side supply path 33, the valve 45 of the anode side discharge path 36, the valve 47 of the hydrogen recirculation path 38, and the valve 48 of the storage section connection path 39. The hydrogen storage unit 11 is controlled to discharge the gas (hydrogen) stored in the hydrogen storage unit 11 as well as the valve.

After replacing nitrogen in the anode 12 with hydrogen, the cathode side control unit 2 D supplies air to the cathode 13.
Here, at the time of stop control, when the volume of the gas stored in the hydrogen storage unit 11 becomes equal to the volume of the anode 12, the anode side control unit 2C determines that the anode 12 is filled with nitrogen and Since the supply of air has been stopped, hydrogen of the same amount as the capacity of the anode 12 is stored in the hydrogen storage part 11 at the start of the start control. For this reason, when it is detected that all the gas in the hydrogen storage unit 11 has been discharged based on the remaining amount of gas in the hydrogen storage unit 11, the anode side control unit 2C and the cathode side control unit 2D Judge as full.

The cathode control unit 2D starts the supply of air to the cathode 13 when the anode 12 is filled with hydrogen. Specifically, the air supply device 8 is started, and the valve 43 of the cathode side supply passage 34 and the valve 46 of the cathode side discharge passage 37 are opened.
In addition, the anode side control unit 2C opens the valve 49 of the hydrogen recirculation passage 38, and closes the valve 45 of the anode side discharge passage 36 and the valve 48 of the storage unit connection passage 39. Start up.

  As shown in (4-III) in FIG. 4, the control device 2 determines that the cathode 13 is filled with air after a predetermined time has elapsed since the air supply device 8 is operated, and turns the output switch 3B on. By setting the connection state, the output circuit 3 and the fuel cell 1 are connected. Thereby, the fuel cell 1 is started.

[4. Action, effect]
(1) According to the control device 2 of the fuel cell 1 described above, after the air containing oxygen in the cathode 13 is replaced with nitrogen (air in which oxygen is consumed) as the stop control of the fuel cell 1, the anode 12 The anode 12 is replaced with nitrogen by supplying air thereto at a predetermined supply rate. As a result, during the stop control of the fuel cell 1, air containing oxygen is present in the cathode 13, and both hydrogen and air containing oxygen are not present in the anode 12. The increase in voltage can be suppressed. As a result, it is possible to suppress the deterioration of the elements constituting the fuel cell 1.

  In addition, when the above-described stop control is performed, when the fuel cell 1 is completely stopped (when supply of all the gases is stopped), a state in which nitrogen remains in both the anode 12 and the cathode 13 Become. As a result, generation of a potential in the fuel cell 1 can be prevented, and oxygen does not remain in the anode 12 and the cathode 13, so that the elements of the fuel cell 1 are not oxidized and degraded. Therefore, deterioration of the elements of the fuel cell can be suppressed.

(2) In the stop control of the fuel cell 1 described above, the cooling is continued until the battery temperature becomes equal to or lower than the predetermined temperature by performing the cooling step, so that water generated by a chemical reaction in the fuel cell stack 10 is generated. Condenses and remains in the fuel cell stack 10. Also by this, it is possible to suppress the deterioration of each element constituting the fuel cell stack 10 at the time of power generation stop.
(3) In particular, the cathode side control unit 2D described above stops the supply of air when the battery temperature becomes equal to or lower than the predetermined temperature by the execution of the cooling step. Thereby, since the water produced | generated during stop control remains in the fuel cell stack 10 as condensed water, deterioration of each element which comprises the fuel cell stack 10 can be suppressed more effectively.

  (4) According to the control device 2 of the fuel cell 1 described above, as the start-up control of the fuel cell 1, after the nitrogen in the anode 12 is replaced with hydrogen, the nitrogen in the cathode 13 is replaced with air, and then the fuel cell 1 And the output circuit 3 are connected. As a result, even during start-up control of the fuel cell 1, there is no air containing oxygen at the cathode 13 and no air containing both hydrogen and oxygen at the anode 12. It is possible to suppress the high potential of the cell. As a result, deterioration of elements constituting the fuel cell 1 can be suppressed.

  (5) According to the control device 2 of the fuel cell 1 described above, when the fuel cell 1 is stopped and controlled, the anode side control unit 2C acquires the cell voltage from the voltage sensor 16, and the cell voltage becomes less than a predetermined value By determining whether or not, it is determined whether or not the cathode 13 is filled with nitrogen. As described above, by using the voltage value detected by the voltage sensor 16, the nitrogen filling in the cathode 13 can be determined easily and accurately, and the control configuration can be simplified.

[5. Others]
The configuration of the control device 2 of the fuel cell 1 and the configuration of the fuel cell 1 described above are an example, and the present invention is not limited to the configuration described above. Further, the contents of the stop control and the start control are also an example, and are not limited to the above-described control contents.

  In the stop control of the embodiment described above, the cathode side control unit 2D is configured to stop the supply of air when the battery temperature becomes equal to or lower than the predetermined temperature by the execution of the cooling step (that is, the first step is performed). The cooling step may be performed at different timings. In the stop control, the cooling step is not essential and may be omitted. In this case, the control configuration related to cooling (that is, the acquisition unit 2A and the cooling control unit 2B) is not essential and may be omitted.

As a timing for performing the cooling step, for example, the cooling control unit 2B may supply cooling water until the battery temperature becomes a predetermined temperature or less after the supply of air by the anode-side control unit 2C is stopped. In other words, after the third step, the cooling step may be performed.
When the gas supply to the anode 12 and the cathode 13 is stopped, no chemical reaction occurs in the fuel cell stack 10, so there is no heat generation due to power generation. Therefore, the fuel cell 1 can be cooled to the predetermined temperature with less energy by supplying the cooling water until the battery temperature becomes equal to or lower than the predetermined temperature after the air supply is stopped by the anode side control unit 2C.

  In the embodiment described above, the anode controller 2C determines that the anode 12 is filled with nitrogen when the volume of the gas stored in the hydrogen storage 11 becomes equal to the volume of the anode 12 during the stop control. In the above description, the supply of air to the anode 12 is stopped. As a configuration for determining whether or not the anode 12 is filled with nitrogen based on parameters other than the capacity of the gas stored in the hydrogen storage unit 11. Also good.

  For example, a hydrogen sensor may be provided in a portion where the anode 12 and the anode side exhaust passage 36 communicate with each other, and the determination may be made based on the hydrogen concentration detected by the hydrogen sensor. In this case, for example, the anode control unit 2C can determine that the anode 12 is filled with nitrogen when the hydrogen concentration detected by the hydrogen sensor becomes equal to or lower than a predetermined concentration. Further, during start-up control of the fuel cell 1, when the hydrogen concentration detected by the hydrogen sensor at the anode side controller 2C and the cathode side controller 2D becomes equal to or higher than the predetermined concentration, the anode 12 is filled with hydrogen. Can be determined.

Also, instead of or in addition to the hydrogen sensor, a flow rate sensor may be provided to determine the nitrogen filling of the anode 12 based on the flow rate detected by the flow rate sensor.
When the fuel cell 1 is provided with a hydrogen sensor, a flow rate sensor or the like, the hydrogen storage portion 11 is not essential, and the fuel cell 1 may be configured without the hydrogen storage portion 11.

In the embodiment described above, the first reaction gas flowing in the fuel cell stack 10 is hydrogen gas and the second reaction gas is oxygen. However, the first reaction gas and the second reaction gas are each hydrogen. It is good also as gas other than gas and oxygen.
For example, when the fuel cell 1 controlled by the control device 2 of the present embodiment is a solid oxide fuel cell, the first reaction gas may be natural gas and the second reaction gas may be oxygen or the like.
When the fuel cell 1 controlled by the control device 2 of the present embodiment is a molten carbonate fuel cell, the first reaction gas is hydrogen gas, and the second reaction gas is a mixed gas of oxygen and carbon dioxide. It is good also as.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Control apparatus 2A Acquisition part 2B Cooling control part 2C Anode side control part 2D Cathode side control part 3 Output circuit 4 Discharge circuit 7 Hydrogen supply apparatus (1st reaction gas supply apparatus)
8 Air supply device (mixed gas supply device)
10 fuel cell stack 12 anode 13 cathode 16 voltage sensor

Claims (11)

An anode, a cathode, and an electrolyte medium disposed between the anode and the cathode, connected to an output circuit, and a first reaction gas flows in the anode, and a second reaction gas and non-reactant in the cathode A control device of a fuel cell that generates electricity by flowing mixed gas containing gas,
An anode side control unit for supplying the first reaction gas or the mixed gas to the anode;
A cathode control unit that supplies the mixed gas to the cathode;

The cathode side control unit stops the supply of the mixed gas at the time of stop control for shutting off the connection between the fuel cell and the output circuit to stop the fuel cell,
The anode side control unit supplies the mixed gas to the anode at the time of power generation instead of the first reaction gas when the non-reactive gas fills the cathode after the supply control of the mixed gas by the cathode side control unit is stopped. A control device for a fuel cell, comprising: supplying to the anode at a predetermined supply rate which is lower than the rate of the first reaction gas. An acquisition unit for acquiring the temperature of the fuel cell;
A cooling control unit that controls supply of a cooling medium to the fuel cell;
The fuel cell control apparatus according to claim 1, wherein the cooling control unit supplies the cooling medium at least until the temperature falls below a predetermined temperature during the stop control. 3. The fuel cell control device according to claim 2, wherein the cathode side control unit stops the supply of the mixed gas when the temperature becomes equal to or lower than the predetermined temperature. 4. 3. The fuel cell control device according to claim 2, wherein the cooling control unit supplies the cooling medium until the temperature becomes equal to or lower than a predetermined temperature after the supply of the mixed gas by the anode-side control unit is stopped. . At the time of starting control for starting the fuel cell,
The anode control unit supplies the first reaction gas to the anode to replace the non-reaction gas in the anode with the first reaction gas.
The fuel cell control according to any one of claims 1 to 4, wherein the cathode side control unit supplies the mixed gas to the cathode when the anode is filled with the first reaction gas. apparatus. The fuel cell is provided with a voltage sensor for detecting the voltage of the fuel cell,
The anode-side control unit determines that the cathode is filled with the non-reactive gas when the voltage after the supply of the mixed gas by the cathode control unit is less than a predetermined value during the stop control. The control device of a fuel cell according to any one of claims 1 to 5, which is characterized. An anode, a cathode, and an electrolyte medium disposed between the anode and the cathode are connected to an output circuit, and a first reaction gas flows through the anode and a second reaction gas and non-flow through the cathode. A control method of a fuel cell, which generates electric power by flowing mixed gas containing reactive gas,
At the time of stop control for interrupting the connection between the fuel cell and the output circuit to stop the fuel cell,
A first step of stopping supply of the mixed gas to the cathode;
A second step of stopping the supply of the first reaction gas to the anode when the cathode is filled with the non-reaction gas after the first step;
After the second step, instead of the first reaction gas, the mixed gas is supplied to the anode at a predetermined supply rate lower than that of the first reaction gas supplied to the anode during power generation. A method of controlling a fuel cell, comprising the steps of: 8. The method according to claim 7, further comprising a cooling step of supplying cooling water to the fuel cell at least until the temperature of the fuel cell falls below a predetermined temperature. 9. The method of controlling a fuel cell according to claim 8, wherein, in the first step, the supply is stopped when the temperature of the fuel cell becomes equal to or lower than the predetermined temperature by performing the cooling step. The fuel cell control method according to claim 8, wherein the cooling step is performed after the third step. The first reactive gas is supplied to the anode and the non-reactive gas in the anode is replaced with the first reactive gas during start control for starting the fuel cell in which the stop control is performed, and then the cathode The control method of a fuel cell according to any one of claims 7 to 10, wherein the mixed gas is supplied to the fuel cell.

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