JPH08124588A - Operation control device for fuel cell - Google Patents

Abstract

PURPOSE: To stop operation of a fuel cell completely in a short time when the operation is stopped, and to start operating the fuel cell in a short time when the operation is started. CONSTITUTION: Opening/closing valves 31, 41, 33, 43 and switching valves 34, 44 are provided in a supply/discharge side of fuel in a fuel cell 20. Suction pumps 36, 46 and fuel treating equipments 37, 47 are set up in a switching destination of the switching valves 34, 44. When operation is stopped, the opening/closing valves 31, 41 are closed to switch the switching valves 34, 44 so as to connect the fuel cell 20 to the suction pumps 36, 46. Residual fuel in the fuel cell 20 is sucked by the suction pumps 36, 46, to close the opening/ closing valves 33, 43. Since fuel is sucked in a short time, operating the fuel cell 20 can be stopped completely in a short time. In this condition, when the opening/closing valve 31, 41 are opened, fuel is introduced to the fuel cell 20, to enable operating the fuel cell 20 to start immediately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell operation control device, and more particularly to a fuel cell operation control device for performing control when the fuel cell is started or stopped, or when an abnormality is detected.

[0002]

2. Description of the Related Art A fuel cell in a steady operation state immediately stops the supply of fuel and removes the load from the output terminal of the fuel cell, and the electrochemical reaction is immediately performed by the fuel remaining inside the fuel cell, immediately Do not stop power generation. The power generation after the supply of the fuel is stopped may generate an undesired high voltage at the output terminal of the fuel cell in some cases. Therefore, it is necessary to remove the fuel from the inside of the fuel cell to completely stop the power generation of the fuel cell and consume the electric power output until the fuel cell is completely stopped.

In such a fuel cell operation control device for completely stopping the operation of the fuel cell, the fuel filled inside is replaced with an inert gas such as nitrogen gas when the operation of the fuel cell is stopped. A device has been proposed (eg,
JP-A-61-32362). In this device, an inert gas is introduced into the fuel cell, and the fuel filled inside is pushed out by the introduced inert gas. Further, in this device, a resistor is connected to the output terminal of the fuel cell via a switch, and when the operation of the fuel cell is stopped, the switch is opened and closed to connect the output terminal of the fuel cell and the resistor. Connected intermittently, consumes the electric power output from the fuel cell until the fuel filling the inside of the fuel cell is completely replaced with an inert gas, and the undesired high voltage is output between the output terminals of the fuel cell. It prevents the generation of voltage.

[0004]

However, such an operation control device for a fuel cell has a problem that the fuel cell cannot be completely stopped in a short time. When an inert gas is introduced into a fuel cell filled with fuel,
This is because the inert gas and the fuel are mixed with each other, so that a certain amount of time is required to completely convert the inside of the fuel cell into the inert gas. Further, in this fuel cell operation control device,
When starting the operation of the fuel cell, it is necessary to completely replace the inert gas with the fuel, so that there is a problem that the operation of the fuel cell cannot be started in a short time. Further, when the fuel cell is used as a mobile power source, it is not preferable to store a large amount of inert gas due to space or weight, and there is a limit to purging with the inert gas.

The fuel cell operation control device of the present invention aims to solve these problems, completely stop the fuel cell in a short time, and start the operation of the fuel cell in a short time. I picked up.

[0006]

A first fuel cell operation control device of the present invention is a fuel cell operation control device for controlling the operation of a fuel cell, wherein the supply of fuel to the fuel cell is stopped. To stop the operation of the fuel cell, and to output a drive signal to the fuel stop means and the fuel suction means to the fuel cell. And a stop control means for sucking fuel from the fuel cell when the supply of fuel is stopped.

Here, the operation control device for the first fuel cell may be provided with a fuel combustion means for burning the fuel sucked by the fuel suction means. Further, the operation control device for the first fuel cell may be configured to include fuel recovery means for recovering the fuel sucked by the fuel suction means. Alternatively, in the operation control device for the first fuel cell, a gas filling means for filling the fuel cell with a pressure adjusting gas is provided, and the stop time control means outputs a drive signal to the gas filling means, The fuel suction means may be a means for filling the fuel cell with a gas for pressure adjustment as the fuel is sucked from the fuel cell.

A second operation control device for a fuel cell of the present invention is a fuel cell operation control device for controlling the operation of the fuel cell, wherein when the operation of the fuel cell is stopped, the fuel for the fuel cell is supplied to the fuel cell. Stop means for stopping the supply of the fuel cell and filling the fuel cell with the pressure adjusting gas, a gas sucking means for sucking the pressure adjusting gas from the fuel cell, and the start of the operation of the fuel cell, A start time control means for outputting a drive signal to the gas suction means and the stop time processing means, and canceling the stop of the fuel supply to the fuel cell as the pressure adjusting gas is sucked from the fuel cell. The point is to have prepared.

Here, in the operation control device for the first fuel cell or the operation control device for the second fuel cell,
The pressure adjusting gas may be an anode fuel or a cathode fuel.

A third fuel cell operation control device of the present invention is a fuel cell operation control device for controlling the operation of the fuel cell, and fuel stop means for stopping the supply of fuel to the fuel cell. Fuel suction means for sucking fuel from the fuel cell, abnormality detection means for detecting abnormality of the fuel cell, and when an abnormality is detected by the abnormality detection means, a drive signal is sent to the fuel stop means and the fuel suction means. The gist of the present invention is to provide an abnormal condition control means for outputting and sucking fuel from the fuel cell when the supply of fuel to the fuel cell is stopped.

In the operation control device for the third fuel cell, the abnormal condition control means outputs a drive signal to the fuel stop means after the fuel suction means sucks fuel from the fuel cell. It is also possible to adopt a configuration that is means for canceling the stop of the fuel supply to the fuel cell.
Further, in the operation control device for the third fuel cell, the fuel is hydrogen and oxygen, and the abnormality detecting means is a hydrogen sensor for detecting hydrogen in an oxygen-side channel of the fuel cell. You can also do it.

[0012]

In the first fuel cell operation control apparatus of the present invention configured as described above, the fuel stop means stops the supply of fuel to the fuel cell, and the fuel suction means sucks fuel from the fuel cell. . When stopping the operation of the fuel cell, the stop time control means outputs a drive signal to the fuel stop means and the fuel suction means, and sucks the fuel from the fuel cell when the supply of the fuel to the fuel cell is stopped.

Here, in the operation control device for the first fuel cell provided with the fuel burning means, the fuel burning means burns the fuel sucked by the fuel sucking means. Further, in the operation control device of the first fuel cell provided with the fuel recovery means, the fuel recovery means recovers the fuel sucked by the fuel suction means.
In the first fuel cell operation control device including the gas filling means, the gas filling means fills the fuel cell with the pressure adjusting gas, and the stop time control means outputs a drive signal to the gas filling means to supply the fuel. The fuel cell is filled with the pressure adjusting gas as the fuel is sucked from the fuel cell by the suction means.

In the second fuel cell operation control device of the present invention, when the stop time processing means stops the operation of the fuel cell,
The supply of fuel to the fuel cell is stopped and the fuel cell is filled with a pressure adjusting gas. The gas suction means sucks the pressure adjusting gas from the fuel cell. When starting the operation of the fuel cell, the start time control means outputs a drive signal to the gas suction means and the stop time processing means so as to suck the pressure adjusting gas from the fuel cell. Release the supply stop.

In the third fuel cell operation control apparatus of the present invention, the fuel stopping means stops the supply of fuel to the fuel cell. The fuel suction means sucks fuel from the fuel cell, and the abnormality detection means detects abnormality of the fuel cell. When the abnormality detection means detects an abnormality, the abnormality control means outputs a drive signal to the fuel stop means and the fuel suction means, and sucks the fuel from the fuel cell in accordance with the stop of the fuel supply to the fuel cell. .

[0016]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 1 is a block diagram showing an outline of a fuel cell system 10 provided with a fuel cell operation control device according to an embodiment of the present invention. As illustrated, the fuel cell system 10 includes a fuel cell 20 that generates electric power by performing an electrochemical reaction using hydrogen in a fuel gas containing hydrogen and oxygen in an oxidizing gas containing oxygen as fuel, and the fuel cell 20. Fuel gas side suction pump 3 for sucking fuel gas and oxidizing gas from the
6 and the oxidant gas side suction pump 46, and a fuel gas treatment device 37 installed on the downstream side of the fuel gas side suction pump 36 and the oxidant gas side suction pump 46 for burning the fuel gas and the oxidant gas sucked from the fuel cell 20. And an oxidizing gas treatment device 47 and a control device 60 for controlling the operation of the fuel cell 20.

The fuel cell 20 is a polymer electrolyte fuel cell, and is composed of a laminate of a plurality of unit cells, which is not shown. A unit cell is composed of an electrolyte membrane, two gas diffusion electrodes sandwiching the electrolyte membrane, and a collector electrode forming a passage for fuel gas or oxidizing gas with the gas diffusion electrodes. The fuel cell 20 includes a supply flow path for supplying a fuel gas and an oxidizing gas to each unit cell, and a fuel gas side exhaust gas and an oxidizing gas side exhaust gas discharged from the unit cell.
0, and a discharge flow path for discharging to the outside. FIG.
The fuel gas and the oxidizing gas supply passages formed in the fuel cell 20, the exhaust gas exhaust passages, and the fuel gas and oxidizing gas passages formed in the unit cell are collectively shown in FIG. The gas flow path 22 and the oxidizing gas flow path 24 are shown. The fuel gas flow path 22 includes the fuel gas flow path 22.
A pressure sensor 26 for detecting the internal pressure P is installed, and a hydrogen concentration sensor 28 for detecting the hydrogen concentration CH in the oxidizing gas flow path 24 is installed in the oxidizing gas flow path 24. The pressure sensor 26 and the hydrogen concentration sensor 28 are
It is connected to the control device 60.

One ends of the fuel gas passage 22 and the oxidizing gas passage 24 of the fuel cell 20 are connected to a fuel gas supply pipe 30 and an oxidizing gas supply pipe 40. The fuel gas supply pipe 30 and the oxidizing gas supply pipe are connected to each other. 40 is
It is connected to a fuel gas supply device and an oxidizing gas supply device (not shown). Therefore, the fuel gas and the oxidizing gas are supplied to the fuel cell 20 from the fuel gas supply device and the oxidizing gas supply device through the fuel gas supply pipe 30 and the oxidizing gas supply pipe 40. Here, as the fuel gas supply device, for example, a hydrogen cylinder containing liquefied hydrogen, a methanol reforming device that generates a hydrogen-containing gas by methanol reforming, a tank that stores a hydrogen storage alloy that releases the stored hydrogen gas, and the like. Is applicable. Further, the oxidizing gas supply device corresponds to, for example, an air compressor or the like that pressurizes outside air (air) and supplies it to the fuel cell 20.

In the vicinity of the connection between the fuel gas supply pipe 30 and the oxidizing gas supply pipe 40 with the fuel cell 20, a fuel gas which is an on-off valve for supplying and stopping the fuel gas and the oxidizing gas to the fuel cell 20 is provided. Supply valve 31
And an oxidizing gas supply valve 41 is installed.

The other ends of the fuel gas flow passage 22 and the oxidizing gas flow passage 24 of the fuel cell 20 are connected to a fuel gas discharge pipe 32 and an oxidizing gas discharge pipe 42, respectively. The pipe 42 is
It is connected to a fuel gas discharge device and an oxidizing gas discharge device (not shown). Therefore, the exhaust gas of the fuel gas and the oxidizing gas discharged from the fuel cell 20 is sent to the fuel gas discharging device and the oxidizing gas discharging device through the fuel gas discharging pipe 32 and the oxidizing gas discharging pipe 42. Here, as the fuel gas discharge device, for example, a recovery device that recovers unreacted hydrogen from the exhaust gas and then releases the residual gas to the outside air, or a combustion device that combusts the unreacted hydrogen and releases it to the outside air, is applicable. . Further, the oxidizing gas discharging device corresponds to, for example, a combustion device that burns hydrogen that has permeated the electrolyte membrane and then releases it to the outside air.

Near the connection of the fuel gas exhaust pipe 32 and the oxidizing gas exhaust pipe 42 to the fuel cell 20, a fuel gas exhaust valve 33 and an oxidizing gas exhaust valve 43, which are opening / closing valves, are installed, and the downstream side thereof. A fuel gas side switching valve 34 and an oxidizing gas side switching valve 44 are installed in the fuel cell. A fuel gas side suction pipe 35 and an oxidizing gas side suction pipe 45 are branched from the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44, and are connected to the fuel gas side suction pipe 35 and the oxidizing gas side suction pipe 45. The fuel gas side suction pump 36, the oxidizing gas side suction pump 46, the fuel gas processing device 37, and the oxidizing gas processing device 47 are installed in series. Therefore, by the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44, the connection between the fuel cell 20 and the fuel gas discharging device and the oxidizing gas discharging device (not shown), the fuel cell 20, the fuel gas side suction pump 36 and the oxidizing gas are connected. The connection with the side suction pump 46 can be switched.

The two supply valves 31, 41 and the two discharge valves 33, 43 have actuators 31A, 41A and actuators 33 for driving the opening / closing valves.
A and 43A are juxtaposed. Also, both switching valves 3
Actuators 34A and 44A for driving the switching valves are arranged in parallel with each other in the valves 4 and 44. The actuators 31A, 33A, 34A, 41A, 43A, 44A
Is connected to the control device 60, and is drive-controlled by the control device 60. Further, the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 are also connected to the control device 60, and are drive-controlled by the control device 60.

The fuel gas treatment device 37 contains a sintered body filter carrying a platinum catalyst, and guides the exhaust gas on the fuel gas side and the air to this sintered body filter to allow unreacted gas in the exhaust gas. After burning hydrogen on the catalyst, it is released to the atmosphere. Therefore, the fuel gas processing device 37 has an air introduction mechanism (for example, a compressor) that introduces air from the outside air.
Is provided. The oxidizing gas treatment device 47 also houses a sintered body filter carrying a platinum catalyst, guides the exhaust gas on the oxidizing gas side to this sintered body filter, and from the fuel gas passage 22 to the oxidizing gas passage 24. After hydrogen that permeates and is mixed in the oxidizing gas is burned on the catalyst, it is released to the outside air.

FIG. 2 is a block diagram illustrating the electrical configuration of the control system of the fuel cell system 10 centering on the control device 60. As shown in the figure, the control device 60 is configured as a logical operation circuit centering on a microcomputer, and more specifically, drives and controls the fuel gas side suction pump 36 and the actuators 31A of the respective valves according to a preset control program. CPU 62 for executing various arithmetic processes for execution, ROM 64 in which a control program and control data necessary for executing various arithmetic processes in CPU 62 are stored in advance, and various data required for executing various arithmetic processes in CPU 62 R is temporarily read and written
An input interface circuit 68 for inputting detection signals from the AM 66, the pressure sensor 26 and the hydrogen concentration sensor 28,
An output interface circuit 70 that outputs a drive signal to the fuel gas side suction pump 36, the oxidizing gas side suction pump 46, the actuator 31A of each valve, and the like according to the calculation result in the CPU 62 is provided. Further, the control device 60 includes a power supply circuit 72 connected to a battery (not shown), and is configured to supply a necessary voltage to each unit. The control device 60 controls the operation of the fuel cell 20.

Next, the operation of the thus constructed fuel cell system 10 at the time of starting and stopping the operation of the fuel cell 20 will be described. FIG. 3 is a flowchart illustrating an operation start processing routine executed by the control device 60 when the fuel cell 20 starts operation, and FIG. 4 illustrates an operation stop processing routine executed by the control device 60 when the fuel cell 20 is stopped. It is a flowchart. For ease of explanation, the valve state of the fuel cell system 10 in which the fuel cell 20 is in a steady operation state will be described first, and then the operation of the fuel cell 20 in this steady operation state when the operation is stopped will be described. The operation at the start of operation of the fuel cell 20 stopped at the time will be described.

Fuel cell system 10 in a steady operation state
Then, the fuel gas supply valve 31, the fuel gas discharge valve 3
3. The oxidizing gas supply valve 41 and the oxidizing gas discharge valve 43 are both open. Further, the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 connect the fuel cell 20 to a fuel gas discharging device and an oxidizing gas discharging device (not shown). Therefore, the fuel cell 20
Receives the supply of the fuel gas and the oxidizing gas from the fuel gas supply device and the oxidizing gas supply device (not shown) to perform an electrochemical reaction to generate electric power, and to generate the exhaust gas on the fuel gas side and the exhaust gas on the oxidizing gas side by the fuel gas discharge device and It is released to the outside air through the oxidizing gas exhaust device.

When the fuel cell system 10 in such a steady operation state is instructed to stop the operation, the controller 60
Executes the operation stop processing routine shown in FIG. When this routine is executed, first, the CPU 62 stops the load on the fuel cell 20 (step S200).
Subsequently, the CPU 62 causes the actuator 31A of the fuel gas supply valve 31 to pass through the output interface circuit 70.
And actuator 41A of the oxidizing gas supply valve 41
To output a drive signal to close the fuel gas supply valve 31 and the oxidizing gas supply valve 41 (step S210),
The supply of the fuel gas and the oxidizing gas from the fuel gas supply device and the oxidizing gas supply device to the fuel cell 20 is stopped.
The opening / closing driving of the opening / closing valves 31, 41, 33, 43, the switching driving of the switching valves 34, 44, and the driving of the suction pumps 36, 46 are performed by driving the fuel gas supply valve 31 and the oxidizing gas supply valve 41 in step S200. Similarly, the CPU 62 allows the actuators 31A, 3 arranged in parallel to each valve via the output interface circuit 70.
3A, 34A, 41A, 43A, 44A or the suction pumps 36, 46 are output by outputting a drive signal, so that in the following, the CPU 62 simply opens (closes) the valve or starts the operation of the suction pumps 36, 46 ( Stop)).

Next, the CPU 62 causes the fuel gas side switching valve 34 and the fuel gas side switching valve 34 to connect the fuel gas passage 22 and the oxidizing gas passage 24 of the fuel cell 20 to the fuel gas side suction pipe 35 and the oxidizing gas side suction pipe 45. The oxidizing gas side switching valve 44 is switched (step S220). Then, the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 is started (step S230), and the fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24 are sucked. The sucked fuel gas and oxidizing gas are sent to the fuel gas processing device 37 and the oxidizing gas processing device 47, and hydrogen mixed in the fuel gas and the oxidizing gas contains the fuel gas processing device 37 and the oxidizing gas processing device 4.
The catalyst of the sintered body filter housed in No. 7 is burned and released to the outside air.

Next, the CPU 62 reads the pressure P in the fuel gas passage 22 detected by the pressure sensor 26 via the input interface circuit 68 (step S24).
0), the read pressure P is compared with the set value Pset stored in advance in the ROM 64 (step S250).
Here, the set value Pset is the fuel gas side suction pump 36.
And the oxidant gas side suction pump 46 is set to determine the end of the suction operation of the fuel gas and the oxidant gas, and is determined by the capabilities of the fuel gas side suction pump 36 and the oxidant gas side suction pump 46. is there. In the embodiment, the set value Pset is 10 kP in absolute pressure.
a.

When the pressure P is equal to or higher than the set value Pset,
When it is determined that the suction operation by the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 has not ended, the process returns to step S240 again, and the process of reading the pressure P detected by the pressure sensor 26 is executed. Fuel gas channel 22
When the fuel gas and the oxidizing gas in the oxidizing gas passage 24 are sucked and the pressure P becomes smaller than the set value Pset (in the embodiment, after about 3 minutes have elapsed from the start of sucking), C
The PU 62 determines that the suction operation has ended, closes the fuel gas discharge valve 33 and the oxidizing gas discharge valve 43 (step S260), and stops the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 (step S260). S
270). Then, the CPU 62 controls the fuel gas side switching valve 34 and the oxidizing gas so that the fuel gas passage 22 and the oxidizing gas passage 24 are connected to the fuel gas discharging device and the oxidizing gas discharging device (not shown) for the next operation starting process. Switch the side switching valve 44 (step S280),
This routine ends. The fuel gas flow path 22 and the oxidizing gas flow path 24 of the fuel cell 20 whose operation has been stopped in this manner
, The pressure is maintained at the set value Pset.

Next, when the operation of the fuel cell 20 is stopped in this way and the operation start instruction is given to the fuel cell system 10 in the operation stop state, the control device 60 executes the operation start processing routine shown in FIG. To do. When this routine is executed, the CPU 62 firstly determines that the fuel gas supply valve 3
1 and the oxidizing gas supply valve 41 are opened (step S1
00). In the fuel gas flow path 22 and the oxidizing gas flow path 24 of the fuel cell 20 in the operation stop state, the pressure is the set value Pse.
Since the fuel gas is kept at t, the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are immediately filled with the fuel gas and the oxidizing gas. Therefore, the fuel cell 20 can immediately start an electrochemical reaction to start power generation.

Subsequently, the CPU 62 opens the fuel gas exhaust valve 33 and the oxidizing gas exhaust valve 43 (step S110) to bring the fuel cell 20 into a steady operation state. Then, the load on the fuel cell 20 is started (step S
120) and this routine is completed.

When the fuel cell 20 is in a steady operation state, the control device 60 executes an abnormality determination routine (not shown) at predetermined time intervals (for example, every 10 msec). In this routine, the CPU 62 makes the input interface circuit 6
The hydrogen concentration CH in the oxidizing gas channel 24 detected by the hydrogen concentration sensor 28 is read via 8 and compared with a preset concentration (for example, 1%). It is determined that an abnormality has occurred in the operation of the battery 20. When such an abnormality is detected, the control device 6
At 0, the abnormal time processing routine illustrated in FIG. 5 is executed. Hereinafter, the operation of the fuel cell system 10 at the time of abnormality will be described.

When this routine is executed, the CPU 62
First, the same processing as the processing of steps S200 to S260 of the operation stop processing routine shown in FIG. 4 is performed (step S300). That is, the fuel cell 2
The load on 0 is stopped, the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are opened, and the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 are switched. Then, the pressure P in the fuel gas passage 22 is set to the set value Ps.
The fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24 until they become smaller than et are sucked into the fuel gas side suction pump 36 and the oxidizing gas side suction pump 4.
Then, the fuel gas exhaust valve 33 and the oxidizing gas exhaust valve 43 are closed.

Subsequently, the CPU 62 opens the fuel gas supply valve 31 and the oxidizing gas supply valve 41 (step S310), and the fuel gas passage 22 and the oxidizing gas passage 24.
A fuel gas and an oxidizing gas are introduced into. Then, the hydrogen concentration CH detected by the hydrogen concentration sensor 28 is read via the input interface circuit 68 (step S32).
0), the read hydrogen concentration CH is compared with the set value CHset (step S330). Here, the set value CHse
t is set as a maximum value or a value smaller than the maximum value of the hydrogen concentration CH in the oxidizing gas flow channel 24 capable of operating the fuel cell 20 normally, and is set to 1% in the embodiment. .

Therefore, the hydrogen concentration CH is the set value CHs.
When it is smaller than et, it is determined that the abnormality is avoided, and the fuel gas side suction pump 36 and the oxidizing gas side suction pump 4 are determined.
6 is stopped (step S340), and the fuel gas exhaust valve 33 and the oxidizing gas exhaust valve 43 are opened (step S350). Then, the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 are switched (step S36).
0), put the fuel cell 20 in a steady operation state, and
Is started (step S370), and the fuel cell system 10 is returned to the state before the abnormality was detected.

On the other hand, when the hydrogen concentration CH is equal to or higher than the set value CHset in step S330, it is determined that the abnormality is not avoided, and the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are closed (step S380), and the fuel gas is closed. The exhaust valve 33 and the oxidizing gas exhaust valve 43 are opened (step S390). Then, the same processing as steps S240 to S280 of the operation stop processing routine of FIG. 4, that is, the processing of completely stopping the operation of the fuel cell 20 is executed (step S400), and this routine is ended.

The fuel cell system 1 of the embodiment described above
According to 0, when the operation of the fuel cell 20 is stopped, the fuel gas suction pump 36 and the oxidizing gas suction pump 46 suck the fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24. Therefore, as compared with the case where the fuel gas and the oxidizing gas in the fuel gas flow path 22 and the oxidizing gas flow path 24 are replaced with the inert gas, the operation of the fuel cell 20 can be completely stopped in an extremely short time. it can. Therefore, it is not necessary to provide means for consuming the electric power output while the fuel cell 20 is completely stopped. Moreover, an undesired high voltage is not generated between the output terminals of the fuel cell 20.

When starting the operation of the fuel cell 20,
Fuel gas flow path 22 and oxidizing gas flow path 2 kept at low pressure
Since the fuel gas and the oxidizing gas are introduced into the fuel cell 4, the fuel gas flow passage 22 and the oxidizing gas flow passage 24 are replaced with the fuel gas and the oxidizing gas in comparison with the case where the inert gas is replaced with the fuel gas and the oxidizing gas. The operation of the fuel cell 20 can be started in an extremely short time.

Further, according to the fuel cell system 10 of the embodiment, when the abnormality is detected, the fuel gas and the oxidizing gas in the fuel gas passage 22 and the oxidizing gas passage 24 of the fuel cell 20 are exchanged in a short time. The operation of the fuel cell 20 can be restarted. Moreover, when the operation of the fuel cell 20 is restarted, the hydrogen concentration CH in the oxidizing gas channel 24 is detected to check whether the abnormality is avoided, and when the operation of the fuel cell 20 is restarted, the abnormality is avoided. If it is determined that the fuel cell 20 is not operating, the operation of the fuel cell 20 is stopped, so that a highly reliable fuel cell system can be achieved.

Further, according to the fuel cell system 10 of the embodiment, the hydrogen mixed in the sucked fuel gas and the oxidizing gas is burned by the fuel gas processing device 37 and the oxidizing gas processing device 47. It is possible to prevent the flammable fuel gas from flowing out, and to provide a highly safe fuel cell system.

In the embodiment, when sucking the fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24, the pressure sensor 2 installed in the fuel gas passage 22 is sucked.
Although the end of the suction operation was judged when the pressure P detected by 6 became smaller than the set value Pset, a pressure sensor was installed in the oxidizing gas flow path 24 and the end of the suction operation was judged based on this pressure sensor. Or the pressure P in the fuel gas passage 22 is set to the set value Pset after the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 is started.
The time until it becomes smaller is obtained in advance, and the suction operation is completed when the time obtained in advance or more than the time obtained after the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 is started has elapsed. It may be configured to determine that.

In the embodiment, when the operation of the fuel cell 20 is stopped, the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are closed, and then the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 are switched before the fuel is supplied. The suction by the gas side suction pump 36 and the oxidizing gas side suction pump 46 is started (steps S210 to S230), but these operations are performed at the same time, that is, the operation of closing the fuel gas supply valve 31 and the oxidizing gas supply valve 41. The operation of switching the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 and the operation of starting suction by the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 may be performed simultaneously.

In the embodiment, the fuel gas processing device 37 is installed in the fuel gas side suction pipe 35 and the oxidizing gas side suction pipe 45.
And the oxidizing gas treatment device 47 is provided, but the oxidizing gas treatment device 47 is not provided in the oxidizing gas side suction pipe 45,
That is, a configuration in which the fuel gas processing device 37 is provided only on the fuel gas side suction pipe 35 is also suitable. In this case, it is necessary that the amount of hydrogen that permeates from the fuel gas channel 22 to the oxidizing gas channel 24 is extremely small and that no treatment is required. Further, in the embodiment, the fuel gas treatment device 37 and the oxidizing gas treatment device 47 are installed on the downstream side of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46, but the fuel gas side suction pump 36 and the oxidizing gas side suction pump 36 are installed. It may be configured to be installed on the upstream side of the pump 46.

In the embodiment, the fuel gas and the oxidizing gas sucked by the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 are burnt by the fuel gas processing device 37 and the oxidizing gas processing device 47. In the case of a fuel cell system in which hydrogen gas is generated from methanol and used as the fuel gas for the fuel cell 20, the reformer operation is stopped with the fuel gas and the oxidizing gas sucked by the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46. Sometimes, it may be burned with the reforming gas (fuel gas) remaining on the reformer side by a heating burner built in the reformer. In this fuel cell system, it is necessary to stop the operation of the fuel cell 20 as well as the operation of the reformer, and it is also necessary to process the reformed gas (fuel gas) remaining on the reformer side. Since the reformer is equipped with a heating burner because it is necessary to apply heat when generating hydrogen gas from methanol, the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 are used for this heating burner. The sucked fuel gas and oxidizing gas can be supplied and burned together with the reformed gas (fuel gas) remaining on the reformer side. With such a configuration, the fuel gas processing device 37 and the oxidizing gas processing device 47 can be omitted, the cost can be reduced, and the space can be saved. Further, a configuration in which a fuel gas recovery device is installed instead of the fuel gas processing device 37 is also suitable. As the fuel gas recovery device, there is a hydrogen storage alloy tank containing a hydrogen storage alloy capable of storing hydrogen. If the fuel gas recovery device is installed in this way, power can be generated from the recovered fuel gas, and the efficiency of the fuel gas can be improved.

In the embodiment, the fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24 are sucked into the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46, respectively.
However, the fuel gas side suction pump 36 sucks only the fuel gas remaining in the fuel gas passage 22 without providing the oxidation gas side suction pump 46, and the fuel gas side suction pump 36 is not provided. There may be a configuration in which only the oxidizing gas remaining in 24 is sucked by the oxidizing gas side suction pump 46. In this case, since a pressure difference is generated on both sides of the electrolyte membrane, it is necessary that the electrolyte membrane be sufficiently resistant to this pressure difference and not allow permeation of the oxidizing gas or the fuel gas due to the pressure difference.

Next, a second embodiment of the present invention will be described. FIG. 6 is a block diagram showing a part of the configuration of a fuel cell system 10A including a fuel cell operation control device according to a second embodiment of the present invention. As shown in the figure, the fuel cell system 10A of the second embodiment has the same configuration as the fuel cell system 10 of the first embodiment and has a fuel gas supply valve 31.
Also, a communication pipe 82 that connects the fuel gas supply pipe 30 and the oxidizing gas supply pipe 40 is provided on the downstream side of the oxidizing gas supply valve 41, and the connecting pipe 82 is provided with a communication valve 80 that is an opening / closing valve. Therefore,
Of the configurations of the fuel cell system 10A, the same configurations as those of the fuel cell system 10 of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

An actuator 80A for driving the communication valve 80 to open and close is provided in parallel with the communication valve 80 provided in the communication pipe 82 of the fuel cell system 10A of the second embodiment. This actuator 80A is used in the control device 60.
And is driven and controlled by a drive signal output from the control device 60.

The fuel cell system 10 thus constructed
The control device 60 of A executes the operation start processing routine illustrated in FIG. 7 and the operation stop processing routine illustrated in FIG. 8 at the start and stop of the operation of the fuel cell 20. In the second embodiment as well, for ease of explanation, first, the operation of the fuel cell 20 in the steady operation state when the operation is stopped will be described, and then the fuel cell 20 that is stopped.
The operation at the start of driving will be described. The steady operation state of the fuel cell system 10A is the same as the fuel cell system 10 of the first embodiment except that the communication valve 80 is closed.
It is the same as the steady operation state of.

When an instruction to stop the operation is issued while the fuel cell system 10A is in the steady operation state, the control device 60 executes the operation stop processing routine shown in FIG. When this routine is executed, first, the CPU 62
Executes the same processing as the processing of steps S200 to S250 of the operation stop processing routine executed by the control device 60 of the first embodiment (step S600). That is, the load on the fuel cell 20 is stopped, the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are opened, and the fuel gas side switching valve 34 and the oxidizing gas side switching valve 44 are switched. Then, the fuel gas and the oxidizing gas remaining in the fuel gas passage 22 and the oxidizing gas passage 24 are supplied to the fuel gas side suction pump 36 and the oxidizing gas until the pressure P in the fuel gas passage 22 becomes smaller than the set value Pset. The side suction pump 46 sucks.

When the pressure P in the fuel gas flow passage 22 becomes smaller than the set value Pset, the CPU 62 opens the communication valve 80 and the oxidizing gas supply valve 41 (steps S610 and S620), and the fuel gas flow passage 22 and An oxidizing gas is introduced into the oxidizing gas channel 24. After the elapse of T1 seconds (step S630), the fuel gas discharge valve 3
3 and the oxidizing gas discharge valve 43 are closed (step S
640). Here, the reason why the fuel gas discharge valve 33 and the oxidizing gas discharge valve 43 are not closed until T1 seconds have elapsed after the oxidizing gas supply valve 41 was opened is that the fuel gas passage 2
When the oxidizing gas is introduced into the fuel cell 2, the fuel gas passage 22
This is because the fuel gas remains in the fuel gas treatment device 37 together with the oxidizing gas, though the fuel gas remains in a very small amount. Therefore, T1 second is set to be equal to or longer than the time required to send the extremely small amount of the fuel gas remaining together with the introduced oxidizing gas to the fuel gas processing device 37.

Thereafter, the CPU 62 stops the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 (step S640), and after a lapse of T2 seconds (step S66).
0), the communication valve 80 and the oxidizing gas supply valve 41 are closed (step S670), and this routine ends. Here, the communication valve 80 and the oxidizing gas supply valve 41 are not closed until T2 seconds have elapsed after the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 are stopped.
This is because the pressure P of the fuel gas passage 22 and the oxidizing gas passage 24 is made to match the pressure of the oxidizing gas supplied by the oxidizing gas supply device (not shown). Therefore, T2 seconds are set as a time or more required to match the pressure P of the fuel gas flow path 22 and the oxidizing gas flow path 24 with the pressure of the oxidizing gas supplied by the oxidizing gas supply device.

In this way, in the fuel cell system 10 in which the oxidizing gas is introduced into the fuel gas flow path 22 and the operation is stopped, when the instruction to start the operation of the fuel cell 20 is given,
The control device 60 executes the operation start processing routine shown in FIG. 7. When this routine is executed, the CPU 62 first opens the fuel gas exhaust valve 33 and the oxidizing gas exhaust valve 43 (step S500), and starts the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46. (Steps S500 and S510), fuel gas flow path 22
And the oxidizing gas in the oxidizing gas channel 24 is sucked. Subsequently, the fuel gas discharge valve 33 and the oxidizing gas discharge valve 43 are waited until the pressure P detected by the pressure sensor 26 installed in the fuel gas flow path 22 becomes smaller than the set value Pset (steps S520 and S530). Is closed (step S540). Then, the operation of the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 is stopped (step S550), and the fuel gas passage 22 and the oxidizing gas passage 24 are connected to a fuel gas discharge device and an oxidizing gas discharge device (not shown). Fuel gas side switching valve 34
And the oxidizing gas side switching valve 44 is switched (step S560).

Next, the fuel gas supply valve 31 and the oxidizing gas supply valve 41 are opened (step S570), and the fuel gas and the oxidizing gas are supplied to the fuel gas passage 22 and the oxidizing gas passage 24 whose pressure is the set value Pset. Introduce gas. Then, the fuel gas exhaust valve 33 and the oxidizing gas exhaust valve 43 are opened (step S580), the fuel cell 20 is brought into a steady operation state, the load on the fuel cell 20 is started (step S590), and this routine is ended.

Also in the fuel cell system 10A of the second embodiment, when an abnormality occurs in the operation of the fuel cell 20, the abnormal time processing is performed. This abnormal time process is the process of step S400 of the abnormal time process routine shown in FIG. 5 executed by the control device 60 of the fuel cell system 10 of the first embodiment (FIG. 4).
8) instead of the steps S240 to S280 of the operation stop processing routine shown in FIG. 8 and the steps S240 and S250 of the operation processing routine shown in FIG.
Step S610 of the operation control stop processing routine shown in FIG.
Through S670. Therefore, since each processing is described above, in the second embodiment,
A flowchart illustrating the abnormal time processing routine and its detailed description are omitted.

According to the fuel cell system 10A of the second embodiment described above, when the operation of the fuel cell 20 is stopped, the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46 are provided.
Since the oxidizing gas is introduced into the fuel gas passage 22 and the oxidizing gas passage 24 after sucking the fuel gas and the oxidizing gas with the fuel gas passage 22 without using such a suction pump.
Also, compared with the case where the fuel gas and the oxidizing gas in the oxidizing gas channel 24 are replaced with the inert gas, the replacement is completed in a short time, and the operation of the fuel cell 20 can be completely stopped. Since the fuel cell 20 completely stops in a short time, it is not necessary to provide means for consuming the electric power output from the fuel cell 20 during that time. Moreover, an undesired high voltage is not generated between the output terminals of the fuel cell 20. further,
When the operation of the fuel cell 20 is stopped, the oxidizing gas (air) is introduced into both the fuel gas flow path 22 and the oxidizing gas flow path 24, so it is possible to stop the fuel cell 20 in an extremely stable state. it can.

In addition, according to the fuel cell system 10A of the embodiment, when the fuel cell 20 is started to operate, the fuel gas passage is pumped by the fuel gas side suction pump 36 and the oxidizing gas side suction pump 46, and then the fuel gas passage Since the fuel gas and the oxidizing gas are introduced into the fuel gas passage 22 and the oxidizing gas passage 24, the inert gas in the fuel gas passage 22 and the oxidizing gas passage 24 is converted into the fuel gas and the oxidizing gas without using such a suction pump. The operation of the fuel cell 20 can be started in a shorter time than in the case of replacement.

In the embodiment, when the operation of the fuel cell 20 is stopped, the fuel gas passage 22 and the oxidizing gas passage 24 are provided.
Although the oxidizing gas is introduced into both of the fuel cells, it is sufficient that no electrochemical reaction is carried out in the fuel cell 20, so the fuel gas passage 2
2 and the oxidizing gas flow path 24, a structure for introducing a fuel gas or other gas (for example, an inert gas such as nitrogen)
It does not matter even if the configuration is introduced.

The embodiment of the present invention has been described above.
The present invention is not limited to these examples at all, for example, a configuration used for operation control of a phosphoric acid fuel cell, within the scope not departing from the gist of the present invention,
Of course, it can be implemented in various modes.

[0060]

As described above, according to the first fuel cell operation control apparatus of the present invention, the fuel remaining in the fuel cell is sucked by the fuel suction means, so that the fuel in the fuel cell is replaced by nitrogen or the like. The operation of the fuel cell can be completely stopped in an extremely short time, as compared with the case where the inert gas is replaced with. Therefore, it is not necessary to provide means for consuming the electric power output from the fuel cell before the fuel cell is completely stopped.

According to the operation control device for the fuel cell having the fuel combustion means, the fuel sucked by the fuel suction means burns the fuel sucked from the fuel cell, so that the outflow of the fuel from the system can be completely prevented.

According to the fuel cell operation control device having the fuel collecting means, the fuel sucked from the fuel cell is collected by the fuel sucking means, so that the fuel cell can make effective use of resources.

According to the operation control device for the fuel cell having the gas filling means, the gas filling means fills the fuel cell with the pressure adjusting gas, so that the fuel cell in the stopped state is brought into an extremely stable state. be able to.

According to the second fuel cell operation control apparatus of the present invention, the fuel is supplied to the fuel cell in association with the suction of the pressure adjusting gas in the fuel cell by the gas suction means, so that the fuel cell is supplied for a short time. It is possible to start the operation of the fuel cell. Of course, during the operation stop of the fuel cell, the fuel cell is filled with the pressure adjusting gas, so that the fuel cell can be brought into an extremely stable state.

In the operation control device for the first fuel cell or the operation control device for the second fuel cell of the present invention, if anode fuel or cathode fuel is used as the pressure adjusting gas,
Since it is not necessary to separately provide a storage container for the pressure adjusting gas, the operation control device for the fuel cell can be downsized.

According to the third operation control apparatus for a fuel cell of the present invention, when the abnormality is detected by the abnormality detecting means, the fuel is sucked from the fuel cell when the supply of the fuel to the fuel cell is stopped. The operation of the fuel cell can be completely stopped in a short time. As a result, the fuel cell is not operated for a long time in a state where the abnormality is detected, so that the operation control device of the fuel cell with high safety can be obtained.

In the third fuel cell operation control device, if the abnormal time control means sucks fuel from the fuel cell and then supplies the fuel to the fuel cell again, the fuel is supplied to the fuel cell in a short time after the abnormality is avoided. Battery operation can be restarted.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a fuel cell system 10 including a fuel cell operation control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a control system centered on a control device 60.

FIG. 3 is a flowchart illustrating an operation start processing routine executed by a CPU 62 of the control device 60.

FIG. 4 is a flowchart illustrating an operation stop processing routine executed by a CPU 62 of the control device 60.

FIG. 5 is a flowchart illustrating an abnormal state processing routine executed by a CPU 62 of the control device 60.

FIG. 6 is a fuel cell system 10A according to a second embodiment of the present invention.
3 is a block diagram showing a part of the configuration of FIG.

FIG. 7 is a flowchart illustrating an operation start processing routine executed by a CPU 62 of the control device 60 according to the second embodiment.

FIG. 8 is a flowchart illustrating an operation stop processing routine executed by a CPU 62 of the control device 60 according to the second embodiment.

[Explanation of symbols]

10, 10A ... Fuel cell system 20 ... Fuel cell 22 ... Fuel gas flow path 24 ... Oxidation gas flow path 26 ... Pressure sensor 28 ... Hydrogen concentration sensor 30 ... Fuel gas supply pipe 31 ... Fuel gas supply valve 32 ... Fuel gas discharge pipe 33 ... Fuel gas discharge valve 34 ... Fuel gas side switching valve 35 ... Fuel gas side suction pipe 36 ... Fuel gas side suction pump 37 ... Fuel gas processing device 40 ... Oxidizing gas supply pipe 41 ... Oxidizing gas supply valve 42 ... Oxidizing gas discharge Pipe 43 ... Oxidizing gas discharge valve 44 ... Oxidizing gas side switching valve 45 ... Oxidizing gas side suction pipe 46 ... Oxidizing gas side suction pump 47 ... Oxidizing gas treatment device 31A, 33A, 34A, 41A, 43A, 44A ... Actuator 60 ... Control Device 62 ... CPU 64 ... ROM 66 ... RAM 68 ... Input interface circuit 70 ... Output interface circuit 72 ... Power supply circuit 80 ... Communication valve 80A ... Actuator 82 ... Communication pipe

Claims (9)

[Claims] 1. A fuel cell operation control device for controlling the operation of a fuel cell, comprising: fuel stop means for stopping the supply of fuel to the fuel cell; and fuel suction means for sucking fuel from the fuel cell. When the operation of the fuel cell is stopped, a drive signal is output to the fuel stop means and the fuel suction means, and the fuel is sucked from the fuel cell when the fuel supply to the fuel cell is stopped. A fuel cell operation control device including a time control means. 2. The operation control device for a fuel cell according to claim 1, further comprising a fuel combustion unit that burns the fuel sucked by the fuel suction unit. 3. The operation control device for a fuel cell according to claim 1, further comprising a fuel recovery unit that recovers the fuel sucked by the fuel suction unit. 4. The operation control device for a fuel cell according to claim 1, further comprising gas filling means for filling the fuel cell with a pressure adjusting gas, wherein the stop time control means is the gas An operation control device for a fuel cell, which is a means for outputting a drive signal to the filling means and filling the fuel cell with a pressure adjusting gas as the fuel is sucked from the fuel cell by the fuel suction means. 5. A fuel cell operation control device for controlling the operation of a fuel cell, wherein when the operation of the fuel cell is stopped, the supply of fuel to the fuel cell is stopped and the pressure of the fuel cell is adjusted. Stop processing means for charging a working gas, gas suction means for sucking a pressure adjusting gas from the fuel cell, and a drive signal to the gas suction means and the stop processing means when starting the operation of the fuel cell. And a start-time control unit that releases the stop of the fuel supply to the fuel cell when the pressure adjusting gas is sucked from the fuel cell. 6. The fuel cell operation control device according to claim 4, wherein the pressure adjusting gas is an anode fuel or a cathode fuel. 7. A fuel cell operation control device for controlling the operation of a fuel cell, comprising: fuel stopping means for stopping the supply of fuel to the fuel cell; and fuel suction means for sucking fuel from the fuel cell. An abnormality detecting means for detecting an abnormality of the fuel cell; and when an abnormality is detected by the abnormality detecting means, a drive signal is output to the fuel stop means and the fuel suction means to supply fuel to the fuel cell. Control device for a fuel cell, comprising an abnormal time control means for sucking fuel from the fuel cell when the fuel cell is stopped 8. The abnormal condition control means outputs a drive signal to the fuel stopping means after the fuel is sucked from the fuel cell by the fuel sucking means to cancel the stop of the fuel supply to the fuel cell. The operation control device for a fuel cell according to claim 7, which is means for performing the operation. 9. The operation control device for a fuel cell according to claim 7, wherein the fuel is hydrogen and oxygen, and the abnormality detecting unit detects hydrogen in the oxygen-side flow passage of the fuel cell. A fuel cell operation control device which is a hydrogen sensor for detection.