JP2001189165A - Fuel cell system, method of stopping and starting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fuel cell system that can reduce the burden on the cost and maintenance without a complicating the system in the purge of a fuel cell system. SOLUTION: This fuel cell system comprises reforming systems (6, 7, 8) for reforming a hydrocarbon-based raw fuel to create H2, a fuel cell (1) for generating power using H2 created at the reforming systems (6, 7, 8) as fuel, means (22) for supplying a purge air to the reforming systems (6, 7, 8) to purge the reforming systems (6, 7, 8) with air, means (22) for supplying O2 to the reforming systems (6, 7, 8) to purge the reforming systems with a completely combusted gas, or means (25) for supplying hydrocarbon gas to the reforming systems to purge the reforming systems with the hydrocarbon gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system, a method for stopping and starting the fuel cell system.

[0002]

2. Description of the Related Art Fuel cells use H ₂ gas fed to a hydrogen electrode.
Is generally known as a power generator in which O ₂ fed into the oxygen electrode is used as an oxidant and these are reacted through an electrolyte. A fuel cell system including such a fuel cell is disclosed in Japanese Patent Application Laid-Open No. 10-308230.

In this fuel cell system, a fuel reformer for reforming hydrocarbons into H ₂ and CO by a partial oxidation reaction represented by the following formula (1), and CO generated in the reforming as follows: 2) Oxidation by a water gas shift reaction shown in the formula,
It has a CO converter for reducing the CO concentration and improving the yield of H ₂ , and a selective oxidation reactor for oxidizing the remaining CO by a selective oxidation reaction shown in the following formula (3) to reduce the remaining CO. A reforming system is provided, and the hydrocarbon-based raw fuel supplied to the reforming system is reformed into H ₂ and sent to the hydrogen electrode. Air is fed into the oxygen electrode. Then, a cell reaction occurs in the fuel cell, and power is generated.

CnHm + nH ₂ O → nCO + (n + m / 2) H ₂ (1) CO + H ₂ O → CO ₂ + H ₂ (2) CO + 1 / 2O ₂ → CO ₂ (3) and When the fuel cell system is stopped, H ₂ and CO remaining in the reforming system are replaced with N ₂ and purged.

[0005]

However, when purging with N ₂ as described above, a cylinder or the like for supplying N ₂ is required, which complicates the structure and increases the cost. Also, maintenance such as replacement of cylinders is required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the cost and maintenance burden of purging a fuel cell system without complicating the system. It is to obtain a fuel cell system.

[0007]

According to the present invention, the purging of the reforming system of the fuel cell system is performed by air, complete combustion gas of raw fuel or hydrocarbon gas.

[0008] More specifically, the invention of the present application is a fuel cell system, a reforming system for generating of H ₂ to hydrocarbon based raw fuel by reforming, H ₂ generated in the reforming system A fuel cell (1) that generates electricity using the fuel as a fuel, and purge air supply means for supplying air to the reforming system to purge the reforming system with air. The supply is stopped, and air is supplied to the reforming system by the purging air supply means. After the temperature of the reforming system becomes equal to or lower than a predetermined temperature, the supply of air is stopped. Is purged with air and stopped.

According to the arrangement, it is possible to purge the reforming system by air, as in the prior art is not necessary to provide a cylinder of N _2, the fuel cell system provided with a conventional N ₂ cylinders In comparison, the system can be simplified and the cost can be reduced. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced.

Here, the reforming system and the hydrogen electrode (3) of the fuel cell (1) may be configured to communicate with each other and to purge with air and stop. With this configuration, the hydrogen electrode (3) of the fuel cell (1) is also purged with air, so that the CO adsorbed on the hydrogen electrode (3) can be oxidized and removed, and the fuel cell (1) can be oxidized and removed. (1) The durability can be improved.

When the raw fuel is reformed in a partial oxidation reforming system, the purge air supply means supplies reforming air for supplying air to the reforming system in order to partially oxidize and reform the raw fuel. It is preferable to also serve as the supply means. This is because the structure of the system can be simplified. Specifically, the purge air supply means and the reforming air supply means are connected to the fuel cell (1).
A reforming air supply pipe (21) that branches off from an air supply pipe (20) that supplies air to the oxygen electrode (2).

A shut-off means (11) for cutting off gas flow between the reforming system and the hydrogen electrode (3) of the fuel cell (1), and a hydrogen electrode (3) of the fuel cell (1). ) May be provided so as to supply air to the cell, and the reforming system and the hydrogen electrode (3) of the fuel cell (1) may be separately purged with air and stopped. . According to such a configuration, the sulfur component oxidized and removed in the reforming system is prevented from flowing into and adsorbing to the fuel cell (1). Specifically, the air supply means for purging the battery is connected to an air supply pipe (20) for supplying air to the oxygen electrode (2) of the fuel cell (1) or a reforming system for partially oxidizing and reforming the raw fuel. A battery purge air supply pipe (22) that branches off from a reforming air supply pipe (21) that supplies air and supplies air to the hydrogen electrode (3) of the fuel cell (1); and a battery purge air supply pipe (22) and an on-off valve (13) interposed therebetween. In this case, only the hydrogen electrode (3) of the fuel cell (1) may be purged with air.

Further, an exhaust heat recovery device (50) for recovering the exhaust heat of the reforming system is provided, and the exhaust heat recovery device (50) is used at the time of a stop operation.
May be configured to stop. According to such a configuration, the temperature of the reforming system increases when the fuel cell system is stopped, and the sulfur component adsorbed on the reforming system can be oxidized and effectively removed.

The reforming system may be provided with an oxidation catalyst. According to such a configuration, even when the raw fuel in the reforming system is reduced during the stop operation of the fuel cell system,
It is possible to completely burn the raw fuel,
The sulfur component adsorbed in the reforming system can be oxidized and reliably removed. And it is desirable that the oxidation catalyst is a noble metal. This is because the catalyst is not oxidized even if the reforming system is purged with air. Examples of such a noble metal include Ru, Pt, Au, and Rh.

The hydrocarbon-based raw fuel is reformed to produce H
₂ , a fuel cell (1) that generates electricity using H ₂ generated in the reforming system as fuel, and an inlet side and an outlet side of a hydrogen electrode (3) of the fuel cell (1). A flow path switching means (11, 12) for switching a flow path to the hydrogen electrode (3) of the fuel cell (1) or the bypass pipe (27); As a method for starting up the fuel cell system in which the fuel cell system is stopped while being purged with air, the reforming system is connected to the bypass pipe (27) by the flow path switching means (11, 12). The raw fuel is supplied to the fuel cell and the reforming of the raw fuel is started, and after the temperature of the reforming system becomes equal to or higher than a predetermined temperature, the reforming system and the hydrogen electrode of the fuel cell (1) are switched by the flow path switching means (11, 12). (3).

[0016] A further aspect of the invention also the fuel cell system of the present application, a reforming system for generating of H ₂ by reforming hydrocarbon based raw fuel, and H ₂ generated in the reforming system as a fuel A fuel cell (1) for power generation, a raw fuel supply control means (14) for controlling a raw fuel supply to the reforming system, and a purging system for purging the reforming system with complete combustion gas of the raw fuel. the O ₂ for the raw fuel combustion and a O ₂ supply means for supplying to the reforming system, the reducing raw fuel supplied to the reforming system by the raw fuel supply amount control means (14), the O _{(2) The} raw fuel is completely burned by supplying O ₂ to the reforming system by the supply means to bring the inside of the reforming system into an oxygen excess state with respect to the stoichiometric air-fuel ratio, so that the temperature of the reforming system is equal to or higher than a predetermined temperature. after a predetermined time later became or stop operation start, by stopping the supply of the raw fuel and O _2, the reforming system And purged with full combustion gas of the fuel, characterized in that it is configured to stop.

According to the arrangement, it is possible to purge the reforming system by complete combustion gas of the raw fuel, conventionally it is not necessary to provide a cylinder of N ₂ as comprising a cylinder of a conventional N ₂ The system can be simplified and the cost can be reduced as compared with the fuel cell system which is used. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced. Further, the sulfur component adsorbed in the reforming system can be oxidized and removed.

When the reforming of the raw fuel is a partial oxidation reforming system, the O ₂ supply means supplies a reforming air supply for supplying air to the reforming system in order to partially oxidize and reform the raw fuel. It is preferable that it also serves as a means. This is because the structure of the system can be simplified. Specifically, the O ₂ supply means and the reforming air supply means are branched from an air supply pipe (20) for supplying air to the oxygen electrode (2) of the fuel cell (1), and the air is supplied to the reforming system. And a reforming air supply pipe (21) for supplying the air.

A shut-off means (11) for cutting off gas flow between the reforming system and the hydrogen electrode (3) of the fuel cell (1), and a hydrogen electrode (3) of the fuel cell (1). ) Which supplies air to the cell, purges the reforming system with complete combustion gas of the raw fuel, and purges and stops the hydrogen electrode (3) of the fuel cell (1) with air. It may be configured as follows. According to this configuration, the hydrogen electrode (3) of the fuel cell (1) is purged with air, so that the inside of the hydrogen electrode (3) is air-bleed and the CO adsorbed on the hydrogen electrode (3) is oxidized. And can be removed,
The durability of the fuel cell (1) can be improved. Specifically, the air supply means for purging the battery includes a fuel cell (1)
From an air supply pipe (20) for supplying air to the oxygen electrode (2) or a reforming air supply pipe (21) for supplying air to the reforming system to partially oxidize and reform the raw fuel. The fuel cell (1) includes an air supply pipe (22) for supplying air to the hydrogen electrode (3) of the fuel cell (1), and an on-off valve (13) interposed in the air supply pipe (22) for battery purge. Can be cited.

The reforming system may be provided with an oxidation catalyst. According to such a configuration, even when the raw fuel in the reforming system is reduced during the stop operation of the fuel cell system,
It is possible to completely burn the raw fuel,
The sulfur component adsorbed in the reforming system can be oxidized and reliably removed. And it is desirable that the oxidation catalyst is a noble metal. This is because the catalyst is not oxidized even if the reforming system is purged with air. Examples of such a noble metal include Ru, Pt, Au, and Rh.

In addition, hydrocarbon-based raw fuel is reformed to produce H ₂
System, a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as fuel, and an inlet and an outlet of a hydrogen electrode (3) of the fuel cell (1) are connected. And a flow path switching means (11, 12) for switching a flow path to the hydrogen electrode (3) of the fuel cell (1) or the bypass pipe (27). As a method of starting up the fuel cell system which is stopped in a state where the fuel cell system is purged with the complete combustion gas of the raw fuel, flow path switching means (11,
In step 12), the reforming system is connected to the bypass pipe (27), and the raw fuel is supplied to the reforming system to start reforming the raw fuel. There is a method of making the reforming system communicate with the hydrogen electrode (3) of the fuel cell (1) by the path switching means (11, 12).

Still another invention of the present application is also a fuel cell system, which comprises a reforming system for reforming a hydrocarbon raw fuel to produce H _2, and a method for converting H ₂ produced in the reforming system to H ₂ . A fuel cell (1) for generating power as fuel; and a hydrocarbon gas supply means for supplying a hydrocarbon gas to the reforming system to purge the reforming system with the hydrocarbon gas. While the reforming of the fuel is stopped, the hydrocarbon gas is supplied to the reforming system by the hydrocarbon gas supply means, and the supply of the hydrocarbon gas is stopped after the temperature of the reforming system falls below a predetermined temperature. Then, the reforming system is configured to be purged with hydrocarbon gas and stopped.

According to the above configuration, the reforming system can be purged by the hydrocarbon gas, so that N
It is not necessary to provide a _second cylinder, it is possible to reduce the simplification and cost of the system compared to the fuel cell system provided with a cylinder of a conventional N _2. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced.

Here, it is preferable that the hydrocarbon gas supply means is a raw fuel supply pipe (25) for supplying raw fuel to the reforming system. According to such a configuration, the structure of the system can be simplified.

A shutoff means (11) for interrupting the flow of gas between the reforming system and the fuel cell (1);
A purge air supply means for supplying air to the hydrogen electrode (3) of the fuel cell (1) such that the hydrogen electrode (3) of the fuel cell (1) is purged with air; The fuel cell (1) may be configured to be purged with hydrogen gas and stopped by purging the hydrogen electrode (3) of the fuel cell (1) with air.
According to this configuration, the hydrogen electrode (3) of the fuel cell (1) is purged with air, so that the inside of the hydrogen electrode (3) is air-bleed and the CO adsorbed on the hydrogen electrode (3) is oxidized. Thus, the durability of the fuel cell (1) can be improved. Specifically, the air supply means for purging the battery is connected to an air supply pipe (20) for supplying air to the oxygen electrode (2) of the fuel cell (1) or a reforming system for partially oxidizing and reforming the raw fuel. Reforming air supply pipe (2
1) A battery purge air supply pipe (22) for supplying air to the hydrogen electrode (3) of the fuel cell (1) branched from the fuel cell (1), and an on-off valve (22) provided in the battery purge air supply pipe (22). 13)
And a configuration having the following.

Also, a bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of the fuel cell (1), and a flow path formed by the hydrogen electrode (3) or the bypass pipe of the fuel cell (1) (2
The configuration may include a flow path switching means (11, 12) for switching to 7). According to such a configuration, even when the CO concentration becomes high when the fuel cell system is started, the bypass pipe (27) can be circulated so that the hydrogen electrode (1) of the fuel cell (1) can be circulated. 3) CO
Can be prevented from flowing in, and deterioration of the fuel cell (1) due to adsorption of CO can be prevented.

[0027] An off-gas burner (10) for burning off-gas of the fuel cell (1) may be provided. According to this configuration, the hydrocarbon gas purged from the reforming system can be completely burned and discharged. In this case, the off-gas burner (10) may be provided with an oxidation catalyst.

Then, the hydrocarbon raw fuel is reformed and H ₂
System, a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as fuel, and an inlet and an outlet of a hydrogen electrode (3) of the fuel cell (1) are connected. And a flow path switching means (11, 12) for switching a flow path to the hydrogen electrode (3) of the fuel cell (1) or the bypass pipe (27). As a method for starting up the fuel cell system which is stopped in a state of being purged with hydrocarbon gas, the reforming system and the bypass pipe (27) are connected by the flow path switching means (11, 12), and the reforming is performed. Supply raw fuel to the system and start reforming the raw fuel,
After the reforming system has reached a predetermined temperature or higher, the flow path switching means (1
1, 12), the reforming system communicates with the hydrogen electrode (3) of the fuel cell (1).

[0029]

As described in the foregoing, according to the invention of the present application, it is possible to purge the reforming system by air, it is not necessary to provide a cylinder of N ₂ as in the prior art conventional N ₂ The system can be simplified and the cost can be reduced as compared with the fuel cell system having the cylinder.
Further, since it is not necessary to replace the cylinder for the purge gas, the maintenance burden can be reduced.

Further, the reforming system communicates with the hydrogen electrode (3) of the fuel cell (1) so that the reforming system is purged with air and stopped, whereby the hydrogen electrode (3) of the fuel cell (1) is stopped. Is also purged with air, so that the CO adsorbed on the hydrogen electrode (3) can be oxidized and removed, and the durability of the fuel cell (1) can be improved.

When the raw fuel is reformed in a partial oxidation reforming system, the purge air supply means is replaced with a reforming air supply means for supplying air to the reforming system for partially oxidizing and reforming the raw fuel. With this configuration, the structure of the system can be simplified.

Further, a shut-off means (11) for cutting off gas flow between the reforming system and the hydrogen electrode (3) of the fuel cell (1), and a hydrogen electrode (3) of the fuel cell (1). ) Is provided with a purge air supply means for supplying air to the fuel cell, and the reforming system and the hydrogen electrode (3) of the fuel cell (1) are separately purged with air and stopped. By purging the quality system with air, it is possible to prevent the sulfur component removed by oxidation from flowing into and adsorbing into the fuel cell (1).

Further, there is provided an exhaust heat recovery device (50) for recovering the exhaust heat of the reforming system, and the exhaust heat recovery device (50) at the time of the stop operation.
Is configured to stop, the temperature of the reforming system will increase during the stop operation of the fuel cell system,
The sulfur component adsorbed on the reforming system can be oxidized and effectively removed.

Further, by employing a configuration in which the reforming system is provided with an oxidation catalyst, even if the raw fuel in the reforming system is reduced when the fuel cell system is stopped, the raw fuel can be completely burned. In addition, the sulfur component adsorbed in the reforming system can be oxidized and reliably removed.
By using a noble metal as the oxidation catalyst, oxidation of the catalyst can be prevented even if the reforming system is purged with air.

According to another aspect of the present invention, since the reforming system can be purged by the complete combustion gas of the raw fuel,
As conventionally is not necessary to provide a cylinder of N _2, it is possible to reduce the simplification and cost of the system compared to the fuel cell system provided with a cylinder of a conventional N _2. Also, it is not necessary to replace the cylinder for the purge gas, etc.
The burden of maintenance can be reduced. further,
The sulfur component adsorbed in the reforming system can be oxidized and removed.

When the raw fuel is reformed in a partial oxidation reforming system, the O ₂ supply means is provided with a reforming air supply means for supplying air to the reforming system for partially oxidizing and reforming the raw fuel. By adopting the configuration that also serves, the structure of the system can be simplified.

Further, a shut-off means (11) for cutting off the gas flow between the reforming system and the hydrogen electrode (3) of the fuel cell (1), and a hydrogen electrode (3) of the fuel cell (1). ) Which supplies air to the cell, purges the reforming system with complete combustion gas of the raw fuel, and purges and stops the hydrogen electrode (3) of the fuel cell (1) with air. The hydrogen electrode (3) of the fuel cell (1)
Is purged with air, the inside of the hydrogen electrode (3) is air-bleed, and CO adsorbed on the hydrogen electrode (3) can be oxidized and removed, thereby improving the durability of the fuel cell (1). Can be achieved.

Further, by employing a configuration in which the reforming system is provided with an oxidation catalyst, even if the raw fuel in the reforming system is reduced at the time of the stop operation of the fuel cell system, the raw fuel can be completely burned. In addition, the sulfur component adsorbed in the reforming system can be oxidized and reliably removed.
By using a noble metal as the oxidation catalyst, oxidation of the catalyst can be prevented even if the reforming system is purged with air.

According to [0039] Another alternative aspect of the present application, it is possible to purge the reforming system by hydrocarbon gas, as in the prior art is not necessary to provide a cylinder of N _2, a cylinder of a conventional N ₂ The system can be simplified and the cost can be reduced as compared with the fuel cell system provided with. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced.

Further, the structure of the system can be simplified by making the hydrocarbon gas supply means a fuel supply pipe for supplying raw fuel to the reforming system.

Further, shut-off means (11) for shutting off the flow of gas between the reforming system and the fuel cell (1);
A purge air supply means for supplying air to the hydrogen electrode (3) of the fuel cell (1) such that the hydrogen electrode (3) of the fuel cell (1) is purged with air; By purging with hydrogen gas and purging the hydrogen electrode (3) of the fuel cell (1) with air and stopping, the hydrogen electrode (3) of the fuel cell (1) is purged with air. Therefore, the inside of the hydrogen electrode (3) is air-bleed, and the CO adsorbed on the hydrogen electrode (3) can be oxidized and removed, and the durability of the fuel cell (1) can be improved.

Further, a bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of the fuel cell (1), and a flow path formed by the hydrogen electrode (3) or the bypass pipe of the fuel cell (1). (2
With the configuration including the flow path switching means (11, 12) for switching to 7), the bypass pipe (27) can be connected even if the CO concentration becomes high when the fuel cell system starts up. By making it available for distribution,
CO can be prevented from flowing into the hydrogen electrode (3) of the fuel cell (1), and deterioration of the fuel cell (1) due to adsorption of CO can be prevented.

Further, by providing an off-gas burner (10) for burning off-gas of the fuel cell (1), the hydrocarbon gas purged from the reforming system can be completely burned and discharged. it can.

[0044]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 -Configuration of Fuel Cell System- FIG. 1 shows a schematic configuration of a fuel cell system according to Embodiment 1. This fuel cell 1 is of a solid polymer membrane electrolyte type having an oxygen electrode (cathode) 2 which is a catalyst electrode and a hydrogen electrode (anode) 3 which is also a catalyst electrode.

An air compressor 4 is connected to the oxygen electrode 2 by an air supply pipe 20.
Is provided with a humidifier 5.

A fuel reformer 6 is connected to the hydrogen electrode 3 by a reformed gas supply pipe 24.
4, a CO converter 7 and a selective oxidation reactor 8 are provided in order toward the fuel cell 1. The first on-off valve 1 is located downstream of the selective oxidation reactor 8 in the reformed gas supply pipe 24.
1 is interposed.

A hydrocarbon-based raw fuel source (city gas) is connected to the fuel reformer 6 by a raw fuel supply pipe 25, and the raw fuel supply pipe 25 is connected to a raw fuel supply amount control valve 14.
And a desulfurizer 9 are provided in order toward the fuel reformer 6. In addition, a reforming air supply pipe 21 for supplying air for partial oxidation reaction is branched from the downstream part of the humidifier 5 of the air supply pipe 20 and connected to a downstream portion of the desulfurizer 9 of the raw fuel supply pipe 25. Have been.

The fuel reformer 6 is filled with a catalyst (catalyst in which Ru or Rh is supported on Al ₂ O ₃ ) exhibiting an activity in the partial oxidation reaction. A catalyst exhibiting activity with respect to the water gas shift reaction (a catalyst in which Pt or Pt-Ru is supported on Al ₂ O ₃ or zeolite) is packed.
A catalyst (Pt, Ru or Pt) exhibiting activity in the selective oxidation reaction
Al ₂ O ₃ or a zeolite consisting by supporting the catalyst) are filled with -ru.

An off-gas burner 10 is provided downstream of the fuel cell 1, and the off-gas of the oxygen electrode 2 and the off-gas of the hydrogen electrode 3 of the fuel cell 1 are led to the off-gas burner 10 from the outlets of the respective electrodes. So that the tubes are connected. The off-gas burner 10 is filled with an oxidation catalyst.

Further, a portion of the reformed gas supply pipe 24 downstream of the selective oxidation reactor 8 and upstream of the first on-off valve 11 is connected to the hydrogen electrode 3 of the fuel cell 1 and the off-gas burner 10. A bypass pipe 27 for connecting the pipe is provided, and the second on-off valve 12 is interposed in the bypass pipe 27. Then, the first on-off valve 11 and the second on-off valve 1
Switching of the flow path from the reformed gas supply pipe 24 to the hydrogen electrode 3 of the fuel cell 1 or the bypass pipe 27 can be performed by opening and closing the valve 2.

Further, a reforming heat exchange section 41 is provided in the CO shift converter 7 and the selective oxidation reactor 8, and a fuel cell heat exchange section 42 is provided in the fuel cell 1. Then, the fuel cell heat exchange section 42, the reforming system heat exchange section 41
Are provided in series in this order.
-Operation during steady operation of fuel cell system-Operation during steady operation of the fuel cell system will be described. In addition,
During a steady operation of the fuel cell system, the first on-off valve 11 is in an open state, and the second on-off valve 12 is in a closed state.

The raw fuel supplied from the raw fuel supply pipe 25 is supplied to the catalyst of the fuel reformer 6 through the desulfurizer 9 together with the air and steam supplied from the reforming air supply pipe 21.
A partial oxidation reaction of the raw fuel occurs on the catalyst of the fuel reformer 6, and H ₂ and CO are generated (see the equation (1)). Also,
Some also cause a water gas shift reaction (see equation (2)).

The reformed gas exiting the fuel reformer 6 is sent to a CO converter 7 where the CO concentration is reduced by a water gas shift reaction occurring on the catalyst (see equation (2)).

The reformed gas exiting the CO shift converter 7 is sent to the selective oxidation reactor 8, where the CO concentration is further reduced by the CO selective oxidation reaction occurring on the catalyst (see equation (3)).

The temperature of the reformed gas leaving the selective oxidation reactor 8 is supplied to the hydrogen electrode 3 of the fuel cell 1.

On the other hand, the air sent from the air compressor 4 is
It is supplied to the oxygen electrode 2 via the humidifier 5.

In the fuel cell 1, 2H ₂ → 4H ⁺ + 4e ^{− on} the electrode surface of the hydrogen electrode 3, and O _{2 on} the electrode surface of the oxygen electrode _2.
A battery reaction of + 4H ⁺ + 4e ⁻ → 2H ₂ O occurs to generate DC power.

At this time, excess air not used in the battery reaction as an off-gas of the oxygen electrode 2 and water vapor generated by the battery reaction are generated, while hydrogen not used in the battery reaction as an off-gas of the hydrogen electrode 3 is generated. , Carbon dioxide, nitrogen, unreformed raw fuel and steam. This oxygen electrode 2
The off-gas of the hydrogen electrode 3 is burned on the catalyst in the off-gas burner 10 and discharged.

Then, waste heat is recovered by the water flowing through the water circuit 50 by the pump 71 in the order of the fuel cell heat exchange section 42 and the reforming system heat exchange section 41. -Shutdown method of fuel cell system-The fuel cell system in a steady operation state is replaced with a fuel reformer 6, a CO converter 7, and a selective oxidation reactor 8.
A method of purging and stopping the reformed gas supply pipe 24 (hereinafter, referred to as “fuel reformer 6 etc.”) and the hydrogen electrode 3 of the fuel cell 1 with air will be described.

First, the supply of the raw fuel is stopped by gradually closing the raw fuel supply amount control valve 14, while the reforming air supply pipe 2 is closed.
By continuously supplying air from 1 to the fuel reformer 6, the inside of the fuel reformer 6 and the inside of the hydrogen electrode 3 of the fuel cell 1 are brought into an oxygen excess state with respect to the stoichiometric air-fuel ratio. Also, the pump 71
Is stopped, and the recovery of exhaust heat from the reforming system (CO converter 7, selective oxidation reactor 8) and fuel cell 1 is stopped. At this time, the noble metal oxidation catalyst (Ru, Rh) is stored in the fuel reformer 6.
Therefore, complete combustion of the raw fuel occurs. Further, the hydrogen electrode 3 of the fuel cell 1 is air-bleed, and the CO adsorbed inside the cell is oxidized. Further, since the exhaust heat recovery is stopped, the temperature of the reforming system (the CO shift converter 7 and the selective oxidation reactor 8) and the fuel cell 1 become high, and the sulfur component adsorbed on the catalyst provided for each of them is also oxidized. The Rukoto.

Next, after the temperatures of the fuel reformer 6 and the like have reached the predetermined temperatures or less, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is stopped. At this time, complete combustion of the raw fuel remaining in the fuel reformer 6 or the like is completed on the catalyst of each reactor or on the catalyst of the off-gas burner 10, and the burned exhaust gas is discharged to the fuel reformer 6 or the like. The inside of the hydrogen electrode 3 of the fuel cell 1 is filled with air.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 are purged with air to stop the fuel cell system. -Starting Method of Fuel Cell System- A starting method of the fuel cell system in which the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 are purged with air will be described.

First, the first on-off valve 11 is closed, and the second on-off valve 12 is opened.

Next, the raw fuel supply amount control valve 14 is gradually opened to supply raw fuel to the fuel reformer 6 and supply of air and steam from the reforming air supply pipe 21 is started.
Also, the supply of air to the off-gas burner 10 is started. At this time, a partial oxidation reaction of the raw fuel in the fuel reformer 6, a water gas shift reaction in the CO shift converter 7, and a CO selective oxidation reaction in the selective oxidation reactor 8, respectively, increase the temperature of each reactor. It will be.
However, at the time of startup, since the composition of the reformed gas is not stable and contains a large amount of CO, the generated reformed gas is burned by the off-gas burner 10 through the bypass pipe 27 and discharged.

After the temperature of the fuel reformer 6 or the like reaches a predetermined temperature or higher, the first on-off valve 11 is opened and the second on-off valve 12 is closed. At this time, each reaction is appropriately performed in each of the heated reactors, and a reformed gas having a stable composition is supplied to the hydrogen electrode 3 of the fuel cell 1 to shift to a steady operation of the fuel cell system. . - Operation and Effects - According to the fuel cell system of the invention, it is possible to purge the fuel reformer 6 and the like by the air, it is not necessary to provide a cylinder of N ₂ as in the prior art, the conventional N ₂ The system can be simplified and the cost can be reduced as compared with a fuel cell system having a cylinder. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced.

Since the hydrogen electrode 3 of the fuel cell 1 is also purged with air, the CO 3 adsorbed on the hydrogen electrode 3 is also purged.
Can be oxidized and removed, and the durability of the fuel cell 1 can be improved.

Further, since the air for purging is supplied by the reforming air supply pipe 21 for supplying air to the fuel reformer 6 for partially oxidizing and reforming the raw fuel, a separate air supplying means is provided. Therefore, the structure of the system is simplified.

Further, since the water circuit 50 for recovering the exhaust heat of the reforming system (the CO shift converter 7 and the selective oxidation reactor 8) is configured to be stopped when the system is stopped, the reforming system ( The temperatures of the CO shift converter 7 and the selective oxidation reactor 8) rise, and the sulfur component adsorbed on the catalyst of each reactor can be oxidized and effectively removed.

Then, the fuel reformer 6 supplies the oxidation catalyst (Ru,
Rh), it is possible to completely burn the raw fuel even if the raw fuel in the fuel reformer 6 is reduced at the time of the shut-down operation of the fuel cell system, and the sulfur component adsorbed on the catalyst Can be removed by oxidation.

The oxidation catalyst (Ru, Rh, Pt, Pt)
Since -Ru) is a noble metal, the catalyst is not oxidized and does not need to be reduced at startup. Embodiment 2 -Configuration of Fuel Cell System- FIG. 2 shows a schematic configuration of a fuel cell system according to Embodiment 2. The same parts as those in the first embodiment are denoted by the same reference numerals.

The fuel cell system according to Embodiment 2 differs from Embodiment 1 in that the reforming air supply pipe 21 is further branched so that air can be supplied to the hydrogen electrode 3 of the fuel cell 1. An air supply pipe 22 for battery purge connected to a downstream portion of the first on-off valve 11 of the gas supply pipe 24 is provided.
The third on-off valve 13 is provided in the battery purge air supply pipe 22. Other configurations are the first embodiment.
Is the same as

The operation of the fuel cell system at the time of steady operation is the same as that of the first embodiment. —Method of Stopping Fuel Cell System— A method of stopping the fuel cell system in a steady operation state by separately purging the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 with air will be described.

First, the first on-off valve 11 is closed, and the second on-off valve 12 and the third on-off valve 13 are opened.

Next, while the supply of the raw fuel is stopped by gradually closing the raw fuel supply amount control valve 14, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is continued. As a result, the inside of the fuel reformer 6 is brought into an oxygen excess state with respect to the stoichiometric air-fuel ratio. Further, air is also supplied from the cell purge air supply pipe 22 to the hydrogen electrode 3 of the fuel cell 1. That is, air is supplied to the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 from different routes. Further, the operation of the pump 71 is stopped, and the recovery of the exhaust heat of the reforming system (the CO shift converter 7, the selective oxidation reactor 8) and the fuel cell 1 is stopped. At this time,
Since the fuel reformer 6 is provided with a noble metal oxidation catalyst (Ru, Rh), complete combustion of the raw fuel occurs. Further, the hydrogen electrode 3 of the fuel cell 1 is air-bleed, and the CO adsorbed inside the cell is oxidized. Further, since the exhaust heat recovery is stopped, the temperature of the reforming system (the CO shift converter 7 and the selective oxidation reactor 8) and the fuel cell 1 become high, and the sulfur component adsorbed on the catalyst provided for each of them is also oxidized. The Rukoto.

Subsequently, after the temperature of the fuel reformer 6 and the like has reached a predetermined temperature or less, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is stopped.
Close. At this time, complete combustion of the raw fuel remaining in the fuel reformer 6 or the like occurs on the catalyst of each reactor or the off-gas burner 1.
The exhaust gas which has been completed on the catalyst No. 0 and burned is discharged, and the inside of the fuel reformer 6 and the like is in a state of being filled with air. Similarly, the inside of the hydrogen electrode 3 of the fuel cell 1 is also filled with air.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 are separately purged with air to stop the fuel cell system. -Starting method of fuel cell system- The starting method of the present fuel cell system is the same as that of the first embodiment. -Operation / Effect- In the fuel cell system having the above configuration, the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 are configured to be separately purged with air. Thus, the inflow and adsorption of the removed sulfur component into the fuel cell 1 are prevented.

Other functions and effects are the same as those of the first embodiment. Embodiment 3-Configuration of Fuel Cell System-The configuration and operation of a fuel cell system according to Embodiment 3 are the same as those in Embodiment 1. —Method of Stopping Fuel Cell System— A method of purging the fuel reformer 6 and the like in the steady operation state by purging with the complete combustion gas of the raw fuel will be described.

First, the first on-off valve 11 is closed, and the second on-off valve 12 is opened.

Next, while gradually reducing the supply of the raw fuel by gradually closing the raw fuel supply amount control valve 14, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is continued. As a result, the inside of the fuel reformer 6 is brought into an oxygen excess state with respect to the stoichiometric air-fuel ratio. At this time, since the fuel reformer 6 is provided with a noble metal oxidation catalyst (Ru, Rh), complete combustion of the raw fuel occurs.

Subsequently, the supply of the raw fuel and the air is stopped after the temperature of the fuel reformer 6 or the like has reached a predetermined temperature or higher, or after a lapse of a predetermined time from the start of the system stop operation. At this time, the inside of the fuel reformer 6 and the like is in a state where the complete combustion gas of the raw fuel is filled.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel reformer 6 and the like are purged with the complete combustion gas of the raw fuel, and the fuel cell system is stopped. - Operation and Effects - According to the fuel cell system of the invention, it is possible to purge the reforming system by complete combustion gas of the raw fuel, it is not necessary as in the prior art providing a bomb N _2, a conventional N _Two
The system can be simplified and the cost can be reduced as compared with the fuel cell system having the cylinder. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced. Further, it is possible to oxidize and remove the sulfur component adsorbed on the catalyst of the fuel reformer 6 or the like.

Further, O ₂ for completely burning the raw fuel is used.
Is supplied by a reforming air supply pipe 21 that supplies air to a reforming system in order to partially oxidize and reform the raw fuel.
The structure of the system is simplified as compared with the case where the O ₂ supply means is separately provided.

Further, the fuel reformer 6 has an oxidation catalyst (Ru,
Rh), the raw fuel in the fuel reformer 6 can be completely burned even when the raw fuel in the fuel reformer 6 is reduced at the time of the stop operation of the fuel cell system. The components can also be reliably oxidized and removed.

Then, the oxidation catalyst (Ru, Rh, P
Since t, Pt-Ru) is a noble metal, the catalyst is not oxidized and does not need to be reduced at startup. (Embodiment 4) The configuration and operation of a fuel cell system according to Embodiment 4 are the same as those of Embodiment 2. -Stopping method of fuel cell system-In the fuel cell system in a steady operation state, the fuel reformer 6 and the like are purged with complete combustion gas of raw fuel, and the hydrogen electrode 3 of the fuel cell 1 is purged with air. A method of stopping will be described.

First, the first on-off valve 11 is closed, and the second on-off valve 12 and the third on-off valve 13 are opened.

Next, while the supply of the raw fuel is reduced by gradually closing the raw fuel supply amount control valve 14, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is continued. As a result, the inside of the fuel reformer 6 is brought into an oxygen excess state with respect to the stoichiometric air-fuel ratio. Further, air is also supplied from the cell purge air supply pipe 22 to the hydrogen electrode 3 of the fuel cell 1. At this time, the noble metal oxidation catalyst (Ru, Rh) is stored in the fuel reformer 6.
Therefore, complete combustion of the raw fuel occurs. Further, the hydrogen electrode 3 of the fuel cell 1 is air-bleed, and the CO adsorbed inside the cell is oxidized.

Subsequently, after the temperature of the fuel reformer 6 or the like has reached a predetermined temperature or higher, or after a lapse of a predetermined time from the start of the system stop operation, supply of the raw fuel and air to the fuel reformer 6 is stopped. The third on-off valve 13 is closed. At this time, the inside of the fuel reformer 6 and the like is in a state where the complete combustion gas of the raw fuel is filled. The hydrogen electrode 3 of the fuel cell 1 is in a state of being filled with air.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel cell system is stopped by purging the fuel reformer 6 and the like with the complete combustion gas of the raw fuel, and purging the hydrogen electrode 3 of the fuel cell 1 with the air. -Starting method of fuel cell system- The starting method of the present fuel cell system is the same as that of the first embodiment. -Operation / Effect- According to the fuel cell system having the above configuration, the hydrogen electrode 3 of the fuel cell 1 is purged with air.
The inside is air bleed, and the CO adsorbed on the hydrogen electrode 3 can be oxidized and removed, and the durability of the fuel cell 1 can be improved.

Other functions and effects are the same as those of the third embodiment. (Embodiment 5) The configuration and operation of the fuel cell system according to Embodiment 5 are the same as those of Embodiment 1. —Method of Stopping Fuel Cell System— A method of stopping the fuel cell system in a steady operation state by purging the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 with hydrocarbon gas will be described.

First, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is gradually reduced and stopped.
The supply of the raw fuel from the raw fuel supply pipe 25 to the fuel reformer 6 is continuously performed. At this time, the fuel reformer 6 gradually becomes oxygen deficient.

Next, after the temperature of each of the fuel reformers 6 and the like has reached a predetermined temperature or less, the fuel reformer 6
The supply of raw fuel to the plant. At this time, the reaction does not occur in the fuel reformer 6 and the like due to the absence of oxygen, and the inside of the fuel reformer 6 and the hydrogen electrode 3 of the fuel cell 1 is filled with the hydrocarbon gas.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel reformer 6 and the like and the hydrogen electrode 3 of the fuel cell 1 are purged with the hydrocarbon gas to stop the fuel cell system. -Starting method of fuel cell system- The starting method of the present fuel cell system is the same as that of the first embodiment. The hydrocarbon gas purged from the fuel reformer 6 and the like is completely burned in the off-gas burner 10 and discharged. - Operation and Effects - According to the fuel cell system of the invention, it is possible to purge the reforming system by hydrocarbon gas, conventionally it is not necessary to provide a cylinder of N ₂ like, cylinder conventional N ₂ The system can be simplified and the cost can be reduced as compared with the fuel cell system provided with. In addition, replacement of the cylinder for the purge gas becomes unnecessary, so that the maintenance burden is reduced.

Since the hydrocarbon gas for purging is supplied from the raw fuel supply pipe 25 for supplying the raw fuel to the fuel reformer 6, the structure of the system is more than the case where a separate hydrocarbon gas supply means is provided. It will be simplified.

Since the off-gas burner 10 is provided, the purged hydrocarbon gas is completely burned and discharged, thereby preventing harmful substances from being released to the outside.

When the fuel cell system is started, C
Even if the O concentration becomes high, the second on-off valve 1
By opening the valve 2 and closing the first on-off valve 11 so that the bypass pipe 27 can be circulated, CO can be prevented from flowing into the hydrogen electrode 3 of the fuel cell 1, and the fuel cell 1 can be prevented from adsorbing CO. Deterioration is prevented. Embodiment 6 The configuration and operation of the fuel cell system according to Embodiment 6 are the same as those of Embodiment 2. -Stopping method of the fuel cell system-Next, the fuel cell system in the steady operation state is purged of the fuel reformer 6 and the like with hydrocarbon gas, and the fuel cell 1
A method for purging and stopping the hydrogen electrode 3 by air will be described.

First, the first on-off valve 11 is closed, and the second on-off valve 12 and the third on-off valve 13 are opened.

Next, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is gradually reduced to stop the supply of air, while the supply of air from the raw fuel supply pipe 25 to the fuel reformer 6 is stopped. Raw fuel supply will be continued. Further, air is supplied from the cell purge air supply pipe 22 to the hydrogen electrode 3 of the fuel cell 1. At this time, the fuel reformer 6 gradually becomes oxygen deficient. Further, the hydrogen electrode 3 of the fuel cell 1 is air-bleed, and the CO adsorbed inside the cell is oxidized.

Then, after the temperature of the fuel reformer 6 and the like has reached a predetermined temperature or less, the supply of air from the reforming air supply pipe 21 to the fuel reformer 6 is stopped.
Close. At this time, since no oxygen is present, no reaction occurs in the fuel reformer 6 and the like, and the inside of the fuel reformer 6 and the like is in a state filled with hydrocarbon gas. The hydrogen electrode 3 of the fuel cell 1 is in a state of being filled with air.

Then, the supply of air to the off-gas burner 10 is stopped. As described above, the fuel reformer 6 and the like are purged with the hydrocarbon gas, and the hydrogen electrode 3 of the fuel cell 1 is purged with the air to stop the fuel cell system. -Starting method of fuel cell system- The starting method of the present fuel cell system is the same as that of the first embodiment. The hydrocarbon gas purged from the fuel reformer 6 and the like is completely burned in the off-gas burner 10 and discharged. -Operation / Effect- According to the fuel cell system having the above-described configuration, the fuel reformer 6 and the like are purged with the hydrocarbon gas, and the hydrogen electrode 3 of the fuel cell 1 is purged with the air. The inside of the fuel cell 3 is air-bleed, and the CO adsorbed on the hydrogen electrode 3 can be oxidized and removed, thereby improving the durability of the fuel cell 1.

Other functions and effects are the same as those of the fifth embodiment.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a fuel cell system according to Embodiments 1, 3, and 5.

FIG. 2 is a schematic configuration diagram of a fuel cell system according to Embodiments 2, 4, and 6.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Oxygen electrode 3 Hydrogen electrode 4 Air compressor 5 Humidifier 6 Fuel reformer 7 CO transformer 8 Selective oxidation reactor 9 Desulfurizer 10 Off gas burner 11 First open / close valve 12 Second open / close valve 13 Third open / close Valve 14 Raw fuel supply amount control valve 20 Air supply pipe 21 Reforming air supply pipe 22 Battery purge air supply pipe 24 Reformed gas supply pipe 25 Raw fuel supply pipe 27 Bypass pipe 41 Reforming system heat exchange unit 42 Fuel cell Heat exchange unit 50 Water circuit 71 Pump

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuji Ikegami 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Factory F-term (reference) 5H027 AA02 BA01 KK42 MM03 MM08 MM12 MM13

Claims (30)

[Claims] 1. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, Purge air supply means for supplying air to the reforming system in order to purge the system with air, wherein supply of raw fuel to the reforming system is stopped, and the reforming air supply means supplies the air to the reforming system. Air is supplied to the reforming system, and after the temperature of the reforming system falls below a predetermined temperature, the supply of air is stopped, and the reforming system is purged with air and stopped. A fuel cell system characterized by the above-mentioned. 2. The fuel cell system according to claim 1, wherein the reforming system and the hydrogen electrode of the fuel cell communicate with each other to purge with air and stop. Fuel cell system. 3. The reforming air supply means for supplying air to the reforming system in order to partially oxidize and reform the raw fuel, wherein the purge air supply means also serves as a reforming air supply means. Or the fuel cell system according to claim 2. 4. The reforming air supply means, which branches from an air supply pipe (20) for supplying air to an oxygen electrode (2) of the fuel cell (1), comprises a purge air supply means and a reforming air supply means. 4. The fuel cell system according to claim 3, wherein the fuel cell system is a reforming air supply pipe (21) for supplying air to the fuel cell. 5. A shut-off means (11) for shutting off a gas flow between the reforming system and the hydrogen electrode (3) of the fuel cell (1), and a hydrogen gas of the fuel cell (1). Pole (3)
And a hydrogen purging means for supplying air to the fuel cell, wherein the reforming system and the hydrogen electrode (3) of the fuel cell (1) are separately purged with air and stopped. The fuel cell system according to any one of claims 1, 3 and 4, wherein 6. The air supply means for purging the battery includes an air supply pipe (20) for supplying air to an oxygen electrode (2) of the fuel cell (1) or the reforming means for partially oxidizing and reforming a raw fuel. A battery purge air supply pipe (22) that branches off from a reforming air supply pipe (21) that supplies air to the quality system and supplies air to a hydrogen electrode (3) of the fuel cell (1); The fuel cell system according to claim 5, further comprising an on-off valve (13) provided in the purge air supply pipe (22). 7. An exhaust heat recovery device (50) for recovering the exhaust heat of the reforming system, wherein the exhaust heat recovery device (5) is used during a stop operation.
The fuel cell system according to any one of claims 1 to 6, wherein 0) is configured to stop. 8. The fuel cell system according to claim 1, wherein the reforming system includes an oxidation catalyst. 9. The fuel cell system according to claim 8, wherein the oxidation catalyst is a noble metal. 10. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating power using H ₂ generated in the reforming system as a fuel, Shut-off means (11) for shutting off gas flow between the system and the hydrogen electrode (3) of the fuel cell (1), and the fuel cell (1)
A battery purging air supply means for supplying air to the hydrogen electrode (3) of the fuel cell (1), wherein the shutoff means (11) cuts off the reforming system and the hydrogen electrode (3) of the fuel cell (1); A fuel cell system, characterized in that the hydrogen electrode (3) of the fuel cell (1) is purged with air and stopped by the cell purging air supply means. 11. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, A purge air supply means for supplying air to the reforming system to purge the system with air, wherein the supply of raw fuel to the reforming system is stopped. At the same time, air is supplied to the reforming system by the purge air supply means, and after the temperature of the reforming system falls below a predetermined temperature, the supply of air is stopped and the reforming system is purged with air. A method for stopping a fuel cell system. 12. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, and the fuel cell (1)
A bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of the fuel cell (1);
Alternatively, there is provided a method for starting up a fuel cell system, comprising: flow path switching means (11, 12) for switching to the bypass pipe (27), wherein the fuel cell system is stopped in a state where the reforming system is purged with air. The reforming system is communicated with the bypass pipe (27) by flow path switching means (11, 12), and raw fuel is supplied to the reforming system to start reforming of the raw fuel. After the temperature of the system reaches or exceeds a predetermined temperature, the flow path switching means (11, 1)
A method for starting up a fuel cell system, wherein the reforming system communicates with the hydrogen electrode (3) of the fuel cell (1) by 2). 13. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, Raw fuel supply control means (14) for controlling the supply of raw fuel to the system
When, a O ₂ supply means for supplying a O ₂ for the raw fuel combustion in order to purge the reforming system with complete combustion gas of the raw fuel to the reforming system, the raw fuel supply amount control means (14 ) optionally with reducing the raw fuel supplied to the reforming system, by a reforming the system by supplying O ₂ to the reforming system in an oxygen-excess state than the theoretical air-fuel ratio by the O ₂ supply means After the raw fuel is completely burned, and after the temperature of the reforming system has become equal to or higher than a predetermined temperature or a predetermined time has elapsed from the start of the stop operation, the supply of the raw fuel and O ₂ is stopped, and Wherein the fuel cell system is configured to be purged with the complete combustion gas and stopped. 14. The reforming air supply means for supplying air to the reforming system for partially oxidizing and reforming the raw fuel, wherein the O ₂ supply means also serves as a reforming air supply means.
3. The fuel cell system according to item 1. 15. The O ₂ supply means and the reforming air supply means are branched from an air supply pipe (20) for supplying air to an oxygen electrode (2) of the fuel cell (1) and are connected to the reforming system. The fuel cell system according to claim 14, wherein the fuel cell system is a reforming air supply pipe (21) for supplying air. 16. A shut-off means (11) for shutting off a flow of gas between the reforming system and a hydrogen electrode (3) of the fuel cell (1); A purge air supply means for supplying air to the pole (3), wherein the reforming system is purged with complete combustion gas of raw fuel, and the hydrogen pole (3) of the fuel cell (1) is purged with air. 2. The apparatus according to claim 1, wherein the apparatus is configured to stop after purging.
The fuel cell system according to any one of claims 3 to 15. 17. The reforming device according to claim 1, wherein the air supply means for purging the battery includes an air supply pipe (20) for supplying air to an oxygen electrode (2) of the fuel cell (1) or the reforming for partial oxidation reforming of a raw fuel. A battery purge air supply pipe (22) that branches off from a reforming air supply pipe (21) that supplies air to the system and supplies air to the hydrogen electrode (3) of the fuel cell (1); The fuel cell system according to claim 16, further comprising an on-off valve (13) interposed in the air supply pipe (22). 18. The fuel cell system according to claim 13, wherein the reforming system includes an oxidation catalyst. 19. The fuel cell system according to claim 18, wherein the oxidation catalyst is a noble metal. 20. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, Raw fuel supply control means (14) for controlling the supply of raw fuel to the system
When, there in the process of stopping the fuel cell system and a O ₂ supply means for supplying a O ₂ for the raw fuel combustion in the reforming system to purge the reforming system with complete combustion gas of the raw fuel Te, by the raw fuel supply amount control means (14) together with reducing the raw fuel supplied to the reforming system, the reforming in system by supplying O ₂ to the reforming system by the O ₂ supply means The raw fuel is completely burned by bringing the oxygen excess from the stoichiometric air-fuel ratio, and after the temperature of the reforming system has become equal to or higher than a predetermined temperature or after a predetermined time has elapsed from the start of the stop operation, the supply of the raw fuel and O ₂ is performed. A method for stopping a fuel cell system, comprising shutting down and purging the reforming system with complete combustion gas of raw fuel. 21. A reforming system for reforming a hydrocarbon-based raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as a fuel, and the fuel cell (1)
A bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of the fuel cell (1);
Alternatively, there is provided a flow switching means (11, 12) for switching to the bypass pipe (27), and a start-up method of a fuel cell system in which the reforming system is stopped in a state of being purged with complete combustion gas of raw fuel. The flow path switching means (11, 12) communicates the reforming system with the bypass pipe (27), and supplies raw fuel to the reforming system to start reforming the raw fuel. After the temperature of the reforming system reaches a predetermined temperature or higher, the flow path switching means (11, 1)
A method for starting up a fuel cell system, wherein the reforming system communicates with the hydrogen electrode (3) of the fuel cell (1) by 2). 22. A reforming system for reforming a hydrocarbon raw fuel to produce H ₂ , a fuel cell (1) for generating electricity using H ₂ produced in the reforming system as fuel, And a hydrocarbon gas supply means for supplying a hydrocarbon gas to the reforming system in order to purge the fuel gas with a hydrocarbon gas, wherein the reforming of the raw fuel in the reforming system is stopped and the hydrocarbon gas supply means is provided. By supplying a hydrocarbon gas to the reforming system, and after the temperature of the reforming system has become a predetermined temperature or less,
A fuel cell system, wherein the supply of hydrocarbon gas is stopped, and the reforming system is purged with hydrocarbon gas and stopped. 23. The fuel cell system according to claim 22, wherein the hydrocarbon gas supply means is a raw fuel supply pipe (22) for supplying raw fuel to the reforming system. 24. A shutoff means (1) capable of shutting off a gas flow between the reforming system and the fuel cell (1).
1) and a battery purge air supply means for supplying air to the hydrogen electrode (3) of the fuel cell (1) such that the hydrogen electrode (3) of the fuel cell (1) is purged with air. 23. The fuel cell according to claim 22, wherein the reforming system is purged with a hydrocarbon gas, and the hydrogen electrode of the fuel cell is purged with air and stopped. Item 24. The fuel cell system according to item 23. 25. The fuel cell (1), wherein the air supply means for purging the fuel is provided with an air supply pipe (20) for supplying air to an oxygen electrode (2) of the fuel cell (1) or the reformer for partially oxidizing and reforming a raw fuel. A battery purge air supply pipe (22) that branches off from a reforming air supply pipe (21) that supplies air to the quality system and supplies air to a hydrogen electrode (3) of the fuel cell (1); 25. The fuel cell system according to claim 24, further comprising an on-off valve (13) provided in the purge air supply pipe (22). 26. A bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of the fuel cell (1), and a flow path formed by the hydrogen electrode (3) or the fuel cell (1). 26. A flow path switching means (11, 12) for switching to said bypass pipe (27).
The fuel cell system according to any one of the above. 27. The fuel cell system according to claim 22, further comprising an off-gas burner (10) for burning off-gas of the fuel cell (1). 28. The fuel cell system according to claim 27, wherein said off-gas burner (10) comprises an oxidation catalyst. 29. A reforming system for reforming a hydrocarbon raw fuel to generate H ₂ , a fuel cell (1) for generating electricity using H ₂ generated in the reforming system as fuel, and the reforming system. A hydrocarbon gas supply means for supplying a hydrocarbon gas to the reforming system in order to purge the fuel cell with the hydrocarbon gas. Is stopped, and the hydrocarbon gas is supplied to the reforming system by the hydrocarbon gas supply means.
A method for stopping a fuel cell system, wherein the supply of hydrocarbon gas is stopped, and the reforming system is purged with hydrocarbon gas and stopped. 30. A reforming system for reforming a hydrocarbon raw fuel to generate H ₂ , a fuel cell (1) for generating power using H ₂ generated in the reforming system as a fuel, and a fuel cell (1). A bypass pipe (27) connecting the inlet side and the outlet side of the hydrogen electrode (3) of 1), and a flow for switching the flow path to the hydrogen electrode (3) of the fuel cell (1) or the bypass pipe (27); Road switching means (1
1, 12) wherein the reforming system is stopped while being purged with a hydrocarbon gas, wherein the reforming system is stopped by the flow path switching means (11, 12). The fuel system and the bypass pipe (27) are communicated with each other, and the raw fuel is supplied to the reforming system to start reforming the raw fuel. Road switching means (11, 1
A method for starting up a fuel cell system, wherein the reforming system communicates with the hydrogen electrode (3) of the fuel cell (1) by 2).