JP2000077086A - Fuel cell power generating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the life of a fuel cell main body and to enhance reliability without decreasing the characteristics of the fuel cell main body by avoiding high temperature and high potential states even when functional damage of a control device is generated. SOLUTION: A hard relay circuit 10 is set in a line of control signals 3s, 4s, 5s from a control device 2 to a pump 3, a cooling fan 4 and an adjusting valve 5 which are a cooling means 31, and a line of a control signal 9s from the control device 2 to nitrogen supply shut off valves 9a, 9b. The hard relay circuit 10 is constituted so as to operate by receiving an abnormal signal 2a from the control device 2 when the function of the control device 2 is damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell power plant automatically operated by a control device, and more particularly to a fuel cell power plant capable of coping with a case where the control device loses its function and an emergency stop of the plant occurs. .

[0002]

2. Description of the Related Art In general, a fuel cell power plant having a fuel cell is a cogeneration type plant having excellent power generation efficiency and clean exhaust characteristics, and is also helped by social demands such as saving resources and preserving the global environment. The research and development is being actively carried out. For example, conventionally, a fuel cell plant that is automatically operated by a control device has been proposed. In this fuel cell power plant, when the plant is stopped, the control device performs automatic cooling and cooling for the fuel cell body and performs gas replacement by supplying an inert gas such as nitrogen gas to the fuel cell body. Thereby, the generated potential of the fuel cell main body is suppressed. A conventional example of such a fuel cell power plant will be specifically described with reference to FIG.

[0003] A fuel cell power plant is composed of a fuel cell main body 1.
A control device 2 for controlling the automatic operation of the plant, a hydrogen-rich gas supply line 20, and an air supply line 30
And a cooling means 31 for cooling the fuel cell body 1 and a gas replacement means 91 for performing gas replacement on the fuel cell body 1. The fuel cell body 1 includes a fuel electrode (anode) 1a having a catalyst layer and an air electrode (cathode) 1b,
A cooling plate 1c is incorporated. The fuel electrode 1a is supplied with hydrogen-rich gas as a fuel from a line 20, and the air electrode 1b is supplied with reaction air as an oxidant from a line 30, and these gases are electrochemically reacted. You get power. Further, a temperature detector 6 for detecting a detected temperature 6s of the cooling water is connected to a cooling water inlet side of the cooling plate 1c.

The cooling means 31 supplies cooling water to the fuel cell main body 1, and includes a pump 3, a cooling fan 4, and a regulating valve 5.
Is incorporated. The gas replacement means 91 includes the fuel cell body 1
And a nitrogen gas cylinder 9 and nitrogen gas supply shut-off valves 9a and 9b.

Further, the control device 2 has a function of controlling the cooling means 31 and the gas replacing means 91 when the plant is stopped to suppress the generated potential of the fuel cell main body 1. More specifically, when the plant stops, the control device 2 takes in the detected temperature 6 s of the cooling water from the temperature detector 6 and sends control signals 3 s and 4 to the pump 3, the cooling fan 4 and the regulating valve 5.
These are operated by sending s and 5s, and the fuel cell body 1 is cooled and cooled. At the same time, the nitrogen gas supply shutoff valve 9
a, 9b by sending a control signal 9s to these valves 9a, 9b.
Is opened, and nitrogen gas is supplied from the nitrogen gas cylinder 9 to the fuel electrode 1a and the air electrode 1b of the fuel cell main body 1 through the lines 20 and 30 to perform gas replacement. In this way, when the plant stops in the fuel cell power plant, the potential generated in the fuel cell main body 1 can be suppressed.

[0006]

However, in the above-described fuel cell power plant, it is rare that an abnormality occurs in the power supply system supplied to the control device 2 or in the control device 2 itself. However, a situation occurs in which the control function is lost. Control device 2 in fuel cell plant
The operation to the fuel cell main body 1 when the function is lost is as follows.

First, at the same time when the load circuit is opened, the hydrogen-rich gas and the air electrode 1b are supplied to the fuel electrode 1a as a supply reaction gas.
To the fuel electrode 1a and the air electrode 1b
Gas is supplied by supplying nitrogen gas to the In this operation, gas replacement of the gas flow passages of the fuel electrode 1a and the air electrode 1b is performed, but the supply reaction gas adsorbed on the electrode catalyst surface cannot be completely removed. for that reason,
In particular, due to the presence of oxygen adsorbed on the air electrode 1b, a state in which a high generated potential, for example, 0.8 V / cell or more is maintained at the air electrode is maintained.

On the other hand, if the function of the control device 2 is lost, the cooling means 31 does not operate. Therefore, fuel electrode 1
a and the catalyst layer in the air electrode 1b are exposed to a high temperature and a high potential state for a long time. This causes a phenomenon such as elution or coarsening of the noble metal component in the catalyst layer, that is, a so-called sintering phenomenon. Therefore, the effective area of the catalyst layer decreases, and the catalyst layer deteriorates. Therefore,
The decrease in the voltage-current characteristic, which is the output characteristic during the power generation operation, is easily accelerated, which may adversely affect the life of the fuel cell body 1.

According to experiments by the inventors, as shown in the graph of FIG. 3, when the electrode catalyst layer of the fuel cell body 1 is exposed to a high potential state of 0.9 V for one hour, the fuel cell body 1 It has been obtained that the higher the temperature is, the more remarkable the reduction of the catalyst surface area accompanying the sintering phenomenon of the catalyst becomes. This result also supports the phenomenon that the high temperature and high potential (0.8 V / cell or more) state in the electrode catalyst layer of the fuel cell main body 1 adversely affects the characteristics of the fuel cell main body 1.

As described above, in the prior art, when the function of the control device 2 is lost, the cooling means 31 does not operate, so that the temperature of the fuel cell main body 1 cannot be cooled and the electric potential generated in the fuel cell main body 1 is suppressed. Function does not work.
As a result, there is a problem that the electrode catalyst layer of the fuel cell main body 1 is deteriorated, and the voltage-current characteristics are significantly reduced.

The present invention has been proposed to solve the above-mentioned problems of the prior art.
By avoiding the high temperature and high potential state of the fuel cell main body even when the function of the control device is lost, the life of the fuel cell main body is extended and the reliability is improved without deteriorating the characteristics of the fuel cell main body. It is to provide a fuel cell power plant.

[0012]

According to a first aspect of the present invention, there is provided a fuel cell power plant which obtains electric power by electrochemically reacting a fuel gas with an oxidizing gas. A main body, and a control device for automatically performing operation of the plant, wherein the control device is provided with a hard relay circuit that suppresses a generated potential of the fuel cell main body, and the control device has lost its function. In such a case, the hard relay circuit is configured to operate. According to the first aspect of the present invention, even in the event that the control device loses its function and the plant is stopped in an emergency, the hard relay circuit operates to suppress the generated potential of the fuel cell body. .

According to a second aspect of the present invention, there is provided the fuel cell power plant according to the first aspect, wherein cooling means is provided for cooling the fuel cell body when the fuel cell power plant stops. Is connected to the hard relay circuit. According to the second aspect of the invention, when the function of the control device is lost and the plant is stopped, the cooling means for cooling the fuel cell main body can be operated by the hard relay circuit.
The temperature of the fuel cell body can be quickly and reliably cooled and lowered, and the generated potential of the fuel cell body can be suppressed.

According to a third aspect of the present invention, in the fuel cell power plant according to the second aspect, the cooling means comprises:
When the temperature of the fuel cell body falls below a predetermined temperature,
It is characterized in that cooling of the fuel cell body is terminated. According to the third aspect of the invention, it is possible to prevent the fuel cell body from being excessively cooled and prevent the electrode catalyst layer from freezing.

The invention corresponding to claim 4 is the first or second invention.
Or the fuel cell power plant according to 3, wherein a load resistor for taking a very small load from the fuel cell body and a switch for opening and closing the load resistor are provided, and the switch is operated to close the switch. The hard relay circuit is connected to the According to the fourth aspect of the invention, when the function of the control device is lost and the plant is stopped, the hard relay circuit closes the switch and the load resistor applies a minute load to the fuel cell body. . Thereby, the oxygen adsorbed on the electrode catalyst layer can be consumed, and the generated potential of the fuel cell main body can be suppressed.

According to a fifth aspect of the present invention, in the fuel cell power plant according to the fourth aspect, a switch restart timer is provided for opening the switch again after a lapse of a predetermined time when the switch is closed by the hard relay circuit. It is characterized by having been. According to the fifth aspect of the invention,
When the function of the control device is lost, the switch is closed by the hard relay circuit to apply a minute load to the fuel cell main body, and after a predetermined time has elapsed, the switch restart timer operates to open this switch again, and the load resistor is used. The operation of lowering the potential of the fuel cell main body can be terminated. As a result, reversal of the fuel cell body can be prevented.

The invention corresponding to claim 6 is claim 1,
6. The fuel cell power plant according to 2, 3, 4 or 5, further comprising a gas supply means for supplying a reducing gas from the outside to the fuel cell body, wherein the gas supply means is provided with an on / off valve. The hard relay circuit is connected to the on / off valve so as to open the on / off valve. According to the invention of claim 6, when the control device loses its function and the plant is stopped, the hard relay circuit opens the on / off valve, and the gas replacement system is connected to the fuel cell main body from the outside. Gas replacement can be performed by supplying an inert gas.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. Note that the same members in the embodiments and the same members as those in the conventional example shown in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted.

(1) First Embodiment [Configuration] A first embodiment according to claims 1, 2 and 3 of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is a configuration diagram of the first embodiment, and FIG. 2 is a configuration diagram of a hard relay circuit.

The structural features of the first embodiment are as follows: lines of control signals 3 s, 4 s, 5 s from the control device 2 to the pump 3, the cooling fan 4 and the regulating valve 5, and supply of nitrogen gas from the control device 2 Control signal 9s to valves 9a and 9b
Is that the hard relay circuit 10 is installed on the line. The hard relay circuit 10 is configured to operate when the control device 2 loses its function in response to the abnormal signal 2a from the control device 2. Hard relay circuit 1
Numeral 0 takes in the detected temperature 6s of the cooling water from the temperature detector 6.

FIG. 2 shows details of the hard relay circuit 10 according to the first embodiment. In FIG. 2, a control power supply 11 that supplies power to a control device 2 is provided, and first, second, and third circuits A, B, and C1 are connected in parallel thereto. The first circuit A includes a lockout relay K1 and a contact 1 for realizing an abnormal signal 2a of the control device 2 by an opening operation.
2, and a lockout relay a contact K11 and a reset button 18 connected in parallel are connected in series. The lockout relay a contact K11 is for self-holding the lockout relay K1.
The reset button 18 is for the lockout relay K1. The second circuit B is configured by connecting a lockout relay b contact K12 and a stop signal input unit 2b of the control device 2 in series.

Third circuit C1 and lockout relay b
The contact K13, the keep relay K2, and the contact 16 are connected in series. Among them, the lockout relay b contact K13 is connected to the lockout relay a contact K14.
Are connected to the nitrogen gas supply cutoff valves 9a and 9b. The keep relay K2 is for forcibly operating the cooling means 31 (specifically, the pump 3, the cooling fan 4 and the regulating valve 5) when the control device 2 is abnormal, and is supplemented through the keep relay a contact K21. Machine 13. Further, the contact 16 operates based on the detected temperature 6 s from the temperature detector 6. When the detected temperature 6 s is higher than a preset temperature, the contact 16 is closed, and when the detected temperature 6 s is lower than the set temperature, the opening operation is performed. It is supposed to do.

[Operation] Next, the operation of the first embodiment will be described. First, when the control device 2 is functioning normally, the lockout relay K1 is in an excited state with the self-holding a contact K11. At this time, the lockout relay b contact K12 is open, and no stop signal is input to the control device 2. Also, lockout relay b contact K1
3 is open and the keep relay K2 is in a non-excited state. Therefore, the contact K21 for forcibly operating the cooling unit 31 is open, and the cooling unit 31 operates as instructed by the control device 2. On the other hand, since the lock-out relay a contact K14 is closed, the nitrogen gas supply cutoff valves 9A and 9b also operate according to commands from the control device.

On the other hand, when an abnormality occurs in the control device 2 and the function of the control device 2 is lost, the abnormality signal 2a
As a result, the contact 12 is opened, and the lockout relay K1 enters a non-excited state. At this time, lockout relay b contact K
12 is closed, and a stop command is input to the control device 2.
If the contact K13 of the lockout relay b is closed and the detected temperature 6s from the temperature detector 6 is equal to or higher than the set temperature, the contact 16 is closed and the keep relay K2 is excited.

By the excitation of the relay K2, the keep relay a contact K21 is closed and the cooling means 31 is forcibly operated. As described above, the cooling means 31 are the pump 3, the cooling fan 4, and the regulating valve 5, and the keep relay a contact K21 is closed, the pump 3 and the cooling fan 4 operate, and the regulating valve 5 is moved to the cooling tower side. Fixed. In this way, the cooling means 31 can reliably and quickly cool and lower the temperature of the fuel cell main body 1. FIG. 3 shows the temperature dependence of the performance deterioration of the fuel cell main body when exposed to the high potential state of 0.9 V for one hour. According to this, it is shown that when the fuel cell body 1 is cooled and the temperature of the electrode catalyst layer falls, the decrease in the catalyst surface area due to the sintering phenomenon of the catalyst is suppressed.

By the way, the detected temperature 6 from the temperature detector 6
When s falls below the set temperature, the contact 16 is opened, and the keep relay K2 is turned off. As a result, the contact K21 for forcibly operating the cooling means 31 is opened, and the cooling means 31 operates as instructed by the control device 2. However, since all the commands from the control device 2 have been cut off, the pump 3 and the cooling fan 4 as the cooling means 31 are stopped, and the cooling and cooling is ended. In the first mode of real death having such an operation, the fuel cell main body 1 is not overcooled. Therefore, the electrode catalyst layer such as phosphoric acid does not freeze.

When the control device 2 loses its function,
The lockout relay b contact K14 is opened, and the nitrogen gas supply cutoff valves 9a and 9b are opened. As a result, nitrogen gas is supplied from the nitrogen gas cylinder 9 to the fuel electrode 1a and the air electrode 1b to perform gas replacement. In this way, in the fuel cell power plant, even if the function of the control device 2 is lost and the plant is stopped immediately, the potential generated in the fuel cell main body 1 can be suppressed.

[Effects] According to the first embodiment described above, by using the hard relay circuit 10, the conventional fuel cell main unit 1 when the plant is stopped by the control device 2
In addition to the operation of suppressing the potential of the above, even in the unlikely event that the control device 2 loses its function and the plant is shut down, the hard relay circuit 10 performs the gas replacement operation with nitrogen,
Since the cooling means 31 can be forcibly operated,
The generation potential of the fuel cell main body 1 can be suppressed, and a decrease in the performance of the fuel cell main body 1 can be avoided. As a result, it is possible to provide a fuel cell power plant in which the life of the fuel cell body is extended and the reliability is improved.

(2) Second Embodiment [Configuration] Next, a second embodiment according to claims 4 and 5 of the present invention will be described.
The embodiment will be described with reference to FIGS. 4 and 5. FIG.
FIG. 4 is a configuration diagram of the second embodiment, and FIG. 5 is a configuration diagram of a hard relay circuit.

In the second embodiment, a load resistor 7 for taking a very small load from the fuel cell body 1 and a switch 7a for opening and closing the resistor 7 are provided, and a control signal to the switch 7a is provided. The configuration is characterized in that the hard relay circuit 10 is provided on the 7s line and the control signal 9s line to the nitrogen gas supply cutoff valves 9a and 9b.

FIG. 5 shows details of the hard relay circuit 10 according to the second embodiment. Hard relay circuit 1 of FIG.
2 differs from the hard relay circuit 10 of FIG. 2 in that the configuration of the third circuit C2 portion and the addition of the fourth circuit D are added, and the other configurations of the first and second circuits A and B are different. Are common. That is, the third circuit C2 includes a lockout relay b contact K13, a keep relay K2, and a contact TR
1 are connected in series. The keep relay K2 is connected to the switch 7a of the load resistor 7 when the control device 2 is abnormal.
To forcibly close the contact, and keep the relay a contact K
22 is connected to the switch 7a. The contact TR1 is opened by the timer relay TR after a predetermined time has elapsed since the keep relay K2 was excited. The fourth circuit D includes the timer relay TR,
A keep relay a contact K23 for operating this timer relay TR is connected in series.

[Operation] Next, the operation of the second embodiment will be described. First, when the control device 2 is normal,
The lockout relay K1 is in an excited state at the self-holding a contact K11. At this time, the lockout relay b contact K1
2 is open, and a stop signal is not input to the control device 2.
The lock-out relay b contact K13 is open, and the keep relay K2 is in a non-excited state. Therefore, the contact K22 for forcibly operating the switch 7a of the load resistor 7 is open, and the load resistor 7 operates as instructed by the control device 2. Further, since the lockout relay a contact K14 is closed, the nitrogen gas supply cutoff valves 9a and 9b also operate as instructed by the control device 2.

On the other hand, when an abnormality occurs in the control device 2 and the function of the control device 2 is lost, when the contact 12 is opened by the abnormality signal 2a, the lockout relay K1 is de-energized. At this time, the lockout relay b contact K1
2 is closed, and a stop command is input to the control device 2. Further, the lockout relay b contact K14 is opened, and the nitrogen gas supply cutoff valves 9a and 9b are opened. This allows fuel electrode 1
A nitrogen gas is supplied from a nitrogen gas cylinder 9 to a and the air electrode 1b to perform gas replacement.

Further, a lock-out relay b contact K13
Is closed, and the keep relay K2 is excited. By the excitation of the keep relay K2, the contact K23 is closed, the timer relay TR is excited, the contact K22 is closed, the switch 7a is closed, and the potential of the fuel cell main body 1 is reduced by the load resistor 7. That is, when the load resistor 7 applies a very small load to the fuel cell main body 1, oxygen adsorbed on the air electrode 1b can be consumed, and the generated potential of the fuel cell main body 1 is reduced to 0.7 V or less. Can be suppressed.

FIG. 6 is a graph showing the performance degradation of the fuel cell main body 1 when the fuel cell main body 1 is exposed to a high temperature of 190 ° C. for 100 hours. As is clear from this graph, when the potential of the fuel cell main body 1 is reduced to 0.8 V or less, the decrease in the catalyst surface area due to the sintering phenomenon of the catalyst layer is significantly suppressed.

In the second embodiment, the control device 2
When a predetermined time elapses after an abnormality occurs and the keep relay K2 is excited, the contact T
R1 is opened, and the keep relay K2 is de-energized. As a result, the contact K22 is opened and the load resistor 7 is turned on / off in accordance with a command from the control device 2. However, since all commands from the control device 2 are cut off, the load resistor 7 in the fuel cell main body 1 is disconnected. The potential lowering operation is terminated. Therefore, reversal of the polarity of the fuel cell main body 1 can be prevented.

[Effect] According to the second embodiment as described above, the use of the hard relay circuit 10 enables the control device 2 to perform the conventional operation of suppressing the potential of the fuel cell main body when the plant is stopped. Even if the control device 2 loses its function and the plant is shut down, the hard relay circuit 10
In addition to performing a gas replacement operation with nitrogen, a load resistor is turned on to consume the oxygen adsorbed on the catalyst layer, so that the electrode potential can be suppressed to 0.7 V or less. Therefore, a decrease in the catalyst surface area due to the sintering phenomenon of the electrode catalyst layer can be suppressed, and a decrease in the performance of the fuel cell body can be avoided. Thus, as in the first embodiment, it is possible to provide a fuel cell power plant that has a longer life and a higher reliability in the fuel cell body.

(3) Third Embodiment [Configuration] Next, a third embodiment according to claim 6 of the present invention will be described with reference to FIGS. FIG. 7 is a configuration diagram of the third embodiment, and FIG. 8 is a configuration diagram of a hard relay circuit.

The third embodiment is characterized in that a reducing gas cylinder 8 for supplying a reducing gas such as hydrogen to the fuel electrode 1a and the air electrode 1b of the fuel cell body 1 is provided. . A reducing gas supply cutoff valve 8a is provided on a supply line of the reducing gas to the fuel cell main body 1. Further, a control signal 8s is sent from the control device 2 to the reducing gas supply cutoff valve 8a, and a control signal 9s line from the control device 2 to the nitrogen gas supply cutoff valve 9a, 9b is provided. A hard relay circuit 10 is provided.

FIG. 8 shows details of the hard relay circuit 10 according to the third embodiment. This hard relay circuit 10
Is provided with only the first and second circuits A and B of the hard relay circuit 10 shown in FIG. 2. The lockout relay K1 is connected to the nitrogen gas supply cutoff valves 9a and 9b via the lockout relay a contact K14. The only difference is that the reactive gas supply cutoff valve 8a is connected.

[Operation] In the third embodiment, when the control device 2 loses its function, the lockout relay b contact K14 is opened and the nitrogen gas supply shutoff valves 9a, 9
b and the reducing gas supply cutoff valve 8a are opened. Therefore, the nitrogen gas cylinder 9 supplies nitrogen gas to the fuel electrode 1a and the air electrode 1b, and at the same time, the reducing gas cylinder 8
And a reducing gas is supplied to the air electrode 1b. Therefore,
It is possible to forcibly reduce the potential of the fuel electrode 1a and the air electrode 1b of the fuel cell body 1 to the hydrogen potential (0 V).

[Effect] According to the third embodiment described above, the use of the hard relay circuit 10 allows the control device 2 to perform the conventional operation of suppressing the potential of the fuel cell main body when the plant is stopped. Even if the control device 2 loses its function and the plant is shut down, the hard relay circuit 10
By performing a gas replacement operation with nitrogen and supplying a reducing gas to the fuel electrode 1a and the air electrode 1b, the potential of these electrodes can be significantly reduced to the hydrogen potential (0 V). Therefore, similarly to the second embodiment, a reduction in the catalyst surface area due to the sintering phenomenon of the electrode catalyst layer and a reduction in the performance of the fuel cell body are avoided, and the life of the fuel cell body is improved and the reliability is improved. Can be achieved.

(4) Other Embodiments The present invention is not limited to the above embodiments, and the shapes and the like of the respective constituent members can be appropriately changed. The supply destination may be one of the fuel electrode 1a and the air electrode 1b.

[0044]

As described above, according to the present invention,
With the provision of the hard relay circuit, the high temperature and high potential state of the fuel cell main body can be avoided even if the function of the control device is lost, and the length of the fuel cell main body can be reduced without deteriorating the characteristics of the fuel cell main body. It is possible to provide a fuel cell power plant that has a longer life and improved reliability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a hard relay circuit according to the first embodiment.

FIG. 3 is a graph showing temperature dependence of deterioration of the fuel cell main body according to the first embodiment.

FIG. 4 is a configuration diagram of a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a hard relay circuit according to a second embodiment.

FIG. 6 is a graph showing potential dependence of deterioration of a fuel cell main body according to the second and third embodiments of the present invention.

FIG. 7 is a configuration diagram of a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a hard relay circuit according to a third embodiment.

FIG. 9 is a configuration diagram of a conventional fuel cell power plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel cell main body 1a ... Fuel electrode 1b ... Air electrode 1c ... Cooling plate 2 ... Control device 2a ... Abnormal signal 2b ... Stop command input part 3 ... Pump 3s, 4s, 5s, 7s, 8s, 9s ... Control signal 4 ... Cooling fan 5 ... Adjusting valve 6 ... Temperature detector 6s ... Detected temperature 7 ... Load resistor 7a ... Load resistor switch 8 ... Reducing gas cylinder 8a ... Reducing gas supply cutoff valve 9 ... Nitrogen gas cylinder 9a, 9b ... Nitrogen gas Supply cutoff valve 10: Hard relay circuit 31: Cooling means 91: Gas replacement means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Miyazaki 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Keihin Works (reference) 5H027 AA02 KK48 KK54 MM01 MM09 MM16 MM26

Claims (6)

[Claims] 1. A fuel cell main body which supplies fuel and an oxidant to each of a fuel electrode and an oxidant electrode having a catalyst layer and electrochemically reacts to obtain electric power, and a control device for performing automatic operation are provided. In a fuel cell power plant that is automatically operated by the control device, the control device is provided with a hard relay circuit for suppressing a generated potential of the fuel cell body, and the control device loses a function. Wherein the hard relay circuit is configured to operate. 2. The fuel cell system according to claim 1, further comprising cooling means for cooling the fuel cell body when the fuel cell power plant stops, and wherein the hard relay circuit is connected to the cooling means. Fuel cell power plant. 3. The cooling device according to claim 2, wherein the cooling unit is configured to stop cooling the fuel cell main body when the temperature of the fuel cell main body falls below a predetermined temperature. Fuel cell power plant. 4. A load resistor for taking a very small load from the fuel cell body, and a switch for opening and closing the load resistor are provided, and the switch includes a hard relay for closing the switch. 4. The fuel cell power plant according to claim 1, wherein the circuit is connected. 5. The fuel cell power plant according to claim 4, further comprising a switch restart timer that opens the switch again after a predetermined time has elapsed after the switch has been closed by the hard relay circuit. . 6. A gas supply means for supplying a reducing gas to the fuel cell body, an on / off valve is provided in the gas supply means, and the on / off valve is provided on the on / off valve. The fuel cell power plant according to claim 1, 2, 3, 4, or 5, wherein the hard relay circuit is connected so as to open.