JP2001043873A - Fuel-cell power generating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel-cell power generating plant capable of purging a storage container safely and efficiently by surely removing combustible components and oxygen component included in a purge gas supplied to the storage container of a fuel cell body. SOLUTION: This fuel-cell power generating plant has a fuel cell body 1, a storage container 2 for housing the fuel cell body, and a reformer 5 for generating a reforming gas to be supplied to the fuel cell body. A dehumidifying device 22 is provided therein, and the exhaust gas exhausted from a combustion part of the reformer 5 is dehumidified by the dehumidifying device 22 and then supplied as purge gas to the storage container 2.

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, and more particularly, to a fuel cell power plant that supplies a purge gas to a container housing a fuel cell body.

[0002]

2. Description of the Related Art In general, a fuel cell power plant continuously supplies a fuel and an oxidant from the outside of a cell, and directly changes chemical energy generated by oxidation of the fuel into electric energy.

[0003] This fuel cell power plant usually has a structure shown in FIG.
As shown in FIG. 7, a fuel cell main body 1 for generating an electric current by a chemical reaction and a reformer 5 for generating a fuel gas to be supplied to the fuel cell main body 1 are provided.

The reformer 5 has a reforming section 5a formed of a reforming pipe and a combustion section 5b formed of a burner. A mixed gas of a reforming fuel and steam is introduced into the reforming section 5a. The fuel is heated in the portion 5a, reformed into a hydrogen-rich gas, and supplied to the fuel electrode 3 of the fuel cell body 1 through the conduit 12.

[0005] The fuel cell body 1 comprises a fuel electrode 3 and an oxidizer electrode 4.
And is isolated from the surrounding environment by a storage container 2 that houses the fuel cell body 1.

An oxidant such as oxygen or air is supplied to the oxidant electrode 4 from a conduit 14, and the hydrogen-rich gas and the oxidant react in the fuel cell main body 1 to become exhausted fuel and exhausted oxidant, respectively. It is discharged through 16 and 17 and supplied to the combustion section 5b of the reformer 5. The exhaust fuel and exhaust oxidant introduced into the combustion section 5b are burned in the combustion section 5a, heat the reforming pipe 5a and generate exhaust gas at the same time, and the generated exhaust gas is discharged out of the system through the conduit 20. .

A part of the exhaust gas from the combustion section 5b is supplied to the storage container 2 through the conduit 21 as a purge gas. The purge gas that has passed through the storage container 2 is discharged through the conduit 15 and merges with the exhaust oxidant conduit 17.

In general, the fuel electrode 3 and the oxidant electrode 4 of the fuel cell body 1 have sufficient gas sealing properties, but the fuel and oxidant are stored from the fuel cell body 1 due to aging due to long-term operation. Leakage and accumulation may occur in the container 1. In this case, there is a risk that an unexpected abnormal reaction may occur. Therefore, as described above, the storage container 2 is periodically or constantly purged.

As the purge gas, an inert gas such as nitrogen having no reactivity with fuel or oxidant is desirable, but it is not easy to store a large amount of nitrogen as a high-pressure gas or as a cryogenic liquid.

Therefore, as described above, it is known that the exhaust gas of the combustion section 5b of the reformer 5 is used as the purge gas (see Japanese Patent Application Laid-Open No. 2-226664).

[0011]

However, the exhaust gas from the combustion section 5b of the reformer 5 contains a part of the combustible component and oxygen component of the remaining combustion. Since the combustion amount of the reformer burner greatly varies depending on the load level of the plant, these residual components generally vary greatly depending on the load level and also during the transition period. Therefore, depending on the operating conditions of the plant, the flammable components and oxygen components of the exhaust gas exceed the reference values, either steadily or transiently. May react dangerously with drug causing danger.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to reliably remove combustible components and oxygen components contained in a purge gas supplied to a storage container 2 of a fuel cell main body 1, It is an object of the present invention to provide a fuel cell power plant capable of safely and efficiently purging a containment vessel.

[0013]

In order to achieve the above object, a fuel cell power plant according to the present invention comprises a fuel cell main body, a storage container for accommodating the fuel cell main body, and a reformer for supplying the fuel cell main body. A fuel cell power plant having a reformer that generates a high quality gas, comprising a gas separation device for separating carbon dioxide gas from exhaust fuel gas or the reformed gas discharged from the fuel cell body, It is characterized in that carbon dioxide gas separated by the gas separation device is supplied to a storage container as a purge gas.

Further, the present invention is a fuel cell power plant including a fuel cell main body, a storage container for accommodating the fuel cell main body, and a reformer for generating a reformed gas to be supplied to the fuel cell main body. And a dehumidifier, which dehumidifies exhaust gas discharged from the combustion section of the reformer and supplies the exhaust gas to the storage container as a purge gas.

The present invention is also a fuel cell power plant comprising a fuel cell main body, a storage container for accommodating the fuel cell main body, and a reformer for generating a reformed gas to be supplied to the fuel cell main body. Equipped with a catalytic combustor and a dehumidifier,
The exhaust gas discharged from the combustion section of the reformer and the reformed gas discharged from the reforming section of the reformer are burned in the catalytic combustor, and the exhaust gas discharged from the catalytic combustor is discharged. After being dehumidified by a dehumidifier, the gas is supplied to the storage container as a purge gas.

Further, the present invention provides a fuel cell main body, a storage container for accommodating the fuel cell main body, a reformer for producing a reformed gas to be supplied to the fuel cell main body, and an oxidizing gas supplied to the fuel cell main body. An oxidizing gas source that supplies a fuel cell power plant, comprising a catalytic combustor, wherein the reformed gas and the oxidizing gas are burned in a catalytic combustor,
The exhaust gas discharged from the catalytic combustor is supplied to the storage container as a purge gas.

The present invention is also a fuel cell power plant having a fuel cell main body and a storage container for accommodating the fuel cell main body, comprising an oxygen removing device for removing oxygen from the air. The air from which oxygen has been removed is supplied to the storage container as a purge gas.

[0018]

A carbon dioxide gas is separated from a fuel gas or a reformed gas discharged from a fuel cell body by using a gas separation device, and the carbon dioxide gas is supplied to a storage container as a purge gas.

Further, the exhaust gas discharged from the combustion section of the reformer is dehumidified by a dehumidifier and then supplied to the storage container as a purge gas.

The exhaust gas discharged from the combustion section of the reformer and the reformed gas discharged from the reforming section of the reformer are burned in a catalytic combustor, and the exhaust gas discharged from the catalytic combustor is burned. Is dehumidified by a dehumidifier and then supplied to the storage container as a purge gas.

Further, the reformed gas and the oxidizing gas are burned in a catalytic combustor, and the exhaust gas discharged from the catalytic combustor is supplied to a storage container as a purge gas.

Further, the air from which oxygen has been removed by the oxygen removing device is supplied to the storage container as a purge gas.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel cell power plant according to the present invention will be described below with reference to FIGS.

Referring to FIG. 1, a first embodiment of a fuel cell power plant according to the present invention will be described.

In FIG. 1, reference numeral 1 denotes a fuel cell main body that generates an electric current by causing an electrochemical reaction. The fuel cell main body 1 is housed in a storage container 2. The fuel cell body 1 has a fuel electrode 3 and an oxidant electrode 4 which are porous electrodes.
Are configured with an electrolyte (not shown) in between. The fuel electrode 3 is supplied with hydrogen-rich gas produced by reforming methane gas or the like from outside via a conduit 12 as fuel, and the oxidant electrode 4 is supplied with oxygen from outside via a conduit 14 as an oxidant.

The fuel and the oxidant that have reacted in the combustion cell body 1 are discharged as exhausted fuel and exhausted oxidant via conduits 16 and 17.

A part of the reformed gas supplied through the conduit 12 is supplied to the gas separator 10 through the conduit 12a as a purge gas supply source, and carbon dioxide is separated. The separated carbon dioxide is supplied to the containment vessel 2 through the conduit 13, and the purge gas in the containment vessel 2 is discharged through the purge exhaust gas pipe 15, and the exhaust gas is supplied to the conduit 16.
To join.

As the gas separation device 5, any chemical, physical or other separation method including a separation membrane can be considered.

Next, the operation of this embodiment will be described.

Carbon dioxide is separated from a part of the gas in the conduit 12 of the reformed gas system by the gas separation device 10 such as a permeable membrane. The separated carbon dioxide is supplied to the storage container 2 as a purge gas, and periodically or constantly purges a fuel or an oxidizing agent that may accumulate in the storage container 2. The purge gas is discharged through conduit 15 and merges into conduit 16 of the exhaust fuel system.

According to the structure of the present embodiment, the gas separation device 10 for separating carbon dioxide is provided, so that the gas separation device 10 can separate carbon dioxide from a part of the reformed gas. Then, by supplying the carbon dioxide to the storage container 2 as a purge gas, it is possible to remove adverse effects due to combustible components, oxygen components and the like contained in the purge gas. As a result, it is possible to prevent the purge gas from causing an abnormal reaction with the fuel and the oxidant leaking from the fuel cell main body 1 into the storage container and causing danger, and to purge the storage container 2 safely.

Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 2, the combustion electrode 3 of the combustion cell body 1
A portion of the exhaust fuel discharged from the
a to the blower 14. After the pressure is increased by the blower 14, the exhaust fuel is supplied to the gas separation device 10 through the conduit 18, and carbon dioxide is separated. The operation after the gas separation device 10 is the same as in the first embodiment.

According to this embodiment, carbon dioxide can be separated from the exhaust fuel discharged from the fuel cell body 1,
The purge gas can be generated efficiently.

In both the first embodiment and the second embodiment, the purge gas discharged from the storage container 2 joins the conduit 16 of the exhaust fuel system through the conduit 15, but the conduit 17 of the exhaust air system. And may be discharged outside the system.

Next, third to sixth embodiments of the present invention will be described with reference to FIGS. Third to sixth embodiments
The embodiment solves the conventional problems as described below.

That is, since the main component of the fuel discharged from the fuel electrode 3 supplied to the combustion part 5b of the reformer 5 is hydrogen, the flue gas of the combustion part 5b generally has a water content of 10 to 10.
It is as high as about 20%. When such a gas is used as a purge gas for the body storage container 2 of the fuel cell unit 1, moisture in the gas is easily condensed due to heat radiation in the purge gas inlet pipe 21 or a local part of the storage container 2 as shown in FIG. There was a problem that it occurred.

For example, if the operating pressure in the system is 5 ata, which is a general value in such a plant, the 20% moisture partial pressure in the purge gas becomes 1 ata,
This corresponds to a saturation pressure of 0 ° C. That is, if there is a place where the temperature becomes 100 ° C. or less in the purge gas inlet pipe 21 or the local part of the storage container 2, drain is generated there.

Drainage is harmful in any of the purge gas inlet pipe 21, the blower 23 and the storage container 2 (see FIG. 18). That is, the barge gas inlet pipe 2
If there is no purge gas flow due to the drain blockage at 1, there is a problem of safety of the fuel cell body.

Further, if a drain attack occurs on the impeller of the blower 23, there is a risk of breakage of the blower. Further, when condensed water is generated in the containment vessel 2 and insulation between the fuel electrode 3 and the air electrode 4 which are generally at a high potential and the containment vessel 2 which is at the ground potential becomes defective, an abnormal ground current is generated. The power generation operation cannot be continued because of the flow. Therefore, the generation of drain in the purge gas has a risk of reducing the reliability of the fuel cell power plant.

Hereinafter, the third to sixth embodiments of the present invention will be described. First, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the fuel cell main body 1 has a fuel electrode 3 and an oxidant electrode 4 as an air electrode. Further, a storage container 2 is provided for housing the fuel cell main body 1 and isolating it from the surrounding environment. Is provided. During power generation operation of the fuel cell, an electromotive force is generated between the fuel electrode 3 and the air electrode 4, so that
In general, the fuel cell main body 1, which is a stack of these, has a high potential with respect to the ground, whereas the storage container 2 is grounded for safety and is at the ground potential. On the other hand, the reformer 5 is composed of a reforming section 5a and a combustion section 5b. A reforming fuel such as natural gas or methanol is supplied to the reforming section 5a through a conduit 19 together with steam, and the reformer 5 is hydrogen-rich by steam reforming. The resulting reformed gas is generated. This reformed gas is further supplied to the anode 3 through the conduit 12. In the fuel cell main body 1, after the reformed gas reacts with the air supplied as an oxidant to the air electrode 4 through the conduit 14, the remaining portions that are not consumed are discharged as exhaust fuel and exhaust air as conduits 15 and 15, respectively. It is discharged through 16. The combustor 5b of the reformer 5 has a function of giving the heat generated by combustion to the reforming section 5a as a reforming heat amount for steam reforming. However, in order to improve the efficiency of the fuel cell plant, the combustor 5b has a function. The fuel discharged from the anode 3 is supplied as fuel through the conduit 16a. The combustion air of the combustion section 5b is supplied by a conduit 14a. The exhaust gas burned in the combustion part 5b is discharged out of the system through the conduit 20, and a part of the exhaust gas is discharged into the storage container 2 of the fuel cell main body 1 through the purge gas inlet pipe 2.
The purge gas supplied through the upper blower 11 and passed through the storage container 1c is discharged through the conduit 12. Up to this point, it is the same as the case of the conventional fuel cell power plant shown in FIG.

A feature of this embodiment is that a dehumidifier 22 is provided in the purge gas inlet pipe 21.

As a specific configuration example of the dehumidifying device 22,
A chemical moisture absorbent, moisture adsorbent, moisture separation membrane, or the like can be used.

Next, the operation of this embodiment will be described. A part of the exhaust gas from the combustion section 5 b supplied to the storage container 2 as a purge gas is circulated to the dehumidifier 22. Since the moisture content of the exhaust gas flowing through the dehumidifier 20 decreases, generation of a large amount of drain can be prevented.

By appropriately selecting the dehumidification level of the dehumidification device 22, the moisture saturation temperature in the purge gas can be reduced to a room temperature or lower. In this case, drainage does not occur even if the temperature of the purge gas inlet pipe 21, the blower 23, or the storage container 2 is partially or entirely reduced due to heat radiation. As a result, generation of drain in the purge gas can be prevented.

According to the configuration of the present embodiment, the dehumidifier 22 is provided in the purge gas inlet pipe 21, so that there is no danger of the drain gas being blocked in the purge gas inlet pipe 10 and the drain attack on the blower 23.
Furthermore, there is no danger of causing insulation failure due to the condensed water inside the storage container 2.

As a result, it is possible to provide a fuel cell power plant capable of realizing high reliability.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 4, a catalyst combustor 24 and a dehumidifier 22 are provided downstream of the catalyst combustor 24 in the purge inlet pipe 21.

A part of the exhaust gas discharged from the combustion section 5b of the reformer 5 is supplied to a catalytic combustor 24 through a conduit 21. Further, as the fuel for combustion in the catalytic combustor 24, a part of the reformed gas discharged from the reforming section 5a of the reformer 5 is supplied to the catalytic combustor 24 through the conduit 12c.
The oxygen component remaining in the exhaust gas discharged from the combustion section 5b reacts with the reformed gas discharged from the reforming section 5a in the catalytic combustor 24 to become carbon dioxide or the like. It is also possible to use a part of the fuel exhausted from the fuel electrode 3 of the fuel cell main body 1 as the fuel for combustion in the catalytic combustor 24.

The exhaust gas discharged from the catalytic combustor 24 is supplied as a purge gas to the storage container 2 of the fuel cell body 1 via the dehumidifier 22 and the blower 23.

Next, the operation of this embodiment will be described. Generally, in a fuel cell power plant, a combustion section 5 of a reformer 5
In order to use a part of the exhaust gas discharged from b as a purge gas for the storage container 2, it is desirable that the residual oxygen concentration in the exhaust gas be as low as possible.

On the other hand, the amount of combustion in the combustion section 5b varies greatly depending on the load level of the plant, and also varies due to transient changes. For this reason, in order to always perform stable combustion in the combustion section 5b, air for combustion must be supplied to the conduit 1.
It may be necessary to supply a considerable excess through 4a.

In this case, the concentration of residual oxygen in the exhaust gas discharged from the combustion section 5b does not become small enough to be used as a purge gas.

As shown in FIG. 4, in the present embodiment, a catalytic combustor 24 is provided in the purge gas inlet pipe 21 so that the residual oxygen component in the exhaust gas discharged from the combustion section 5b of the reformer 5 is removed. To consume in. As a result, the exhaust gas discharged from the catalytic combustor 24 is converted into a low-concentration or oxygen-free purge gas sufficient for safety.
Can be supplied to

In this case, in this case, the catalytic combustor 24
The reaction product water at the step adds to the exhaust gas. For this reason, the moisture content in the exhaust gas discharged from the catalytic combustor 24 is higher than the moisture content in the exhaust gas from the combustion section 5b of the reformer, and the risk of drain generation is further increased. However, in the present embodiment, since the dehumidifier 22 is provided downstream of the catalytic combustor 24, the moisture content in the purge gas after leaving the dehumidifier 22 can be reduced. As a result, generation of drain in the purge gas can be prevented.

According to the configuration of the present embodiment, the catalyst inlet 24 is provided with the catalytic combustor 24 and the dehumidifier 22 downstream of the catalytic combustor 24, so that the combustion section 5b of the reformer 5 is stabilized. Combustion air is passed through conduit 14a to effect combustion.
Through the catalytic combustor 2
The exhaust gas discharged from the storage container 4 can be supplied to the storage container 2 as a purge gas having a sufficiently low concentration or containing no oxygen component, which is sufficient for safety. Further, in this case, even if the catalyst combustor 24 is provided in the purge gas inlet pipe 21, the dehumidifier 22 is provided on the downstream side, so that adverse effects due to drainage may occur in the piping, the blower 23, or the inside of the storage container 2. Absent. As a result, it is possible to provide a fuel cell power plant capable of realizing high reliability.

Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 shows another specific configuration example of the dehumidifier 22 in the fuel cell power plant according to the present invention. FIG.
In the above, the purge gas is supplied to the condenser 25 and the steam-water separator 2.
6. By passing the gas through the heat exchanger 27, moisture in the gas is removed. The purge gas is discharged from the condenser 25.
After being cooled by the water and being drain separated by the steam separator 26,
It is reheated by the heat exchanger 27 and is sent out as a superheated gas.
Therefore, there is no danger of draining on the downstream side.

By using such a configuration of the dehumidifying device 22, the same effects as those of the third and fourth embodiments can be obtained.

Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 shows still another specific configuration example of the dehumidifier 22 in the fuel cell power plant according to the present invention. In this embodiment, a contact cooler 28 is provided instead of the condenser 25 and the steam separator 26 in FIG. In this case, the purge gas is drained by the contact cooler 28, reheated by the heat exchanger 27, and sent out as a superheated gas.

By using such a structure of the dehumidifying device 22, the same effects as those of the third and fourth embodiments can be obtained.

Next, a seventh embodiment to a twelfth embodiment of the present invention will be described with reference to FIGS. The seventh to twelfth embodiments solve the conventional problems described below.

That is, in the conventional fuel cell power plant (see FIG. 19) in which the combustion exhaust gas discharged from the combustion section 5b of the reformer 5 is used as the purge gas for the containment vessel 2, the reforming is performed depending on various operating conditions of the plant. Since the combustion amount of the device 5 is largely different, the oxygen concentration in the flue gas is not always constant, but greatly fluctuates particularly due to a load level and a transient change. For this reason, the fluctuation of the oxygen concentration in the purge gas in the storage container 2 is large, and when the fluctuation causes the oxygen concentration to exceed a certain level, the battery container cannot always be safely purged. there were.

Hereinafter, seventh to twelfth embodiments of the present invention will be described. First, a seventh embodiment will be described with reference to FIG. In FIG. 7, the fuel cell body 1 includes a fuel electrode 3 as an anode electrode, an oxygen agent electrode 4 as a cathode electrode, and a cell stack in which these are laminated. The fuel cell body 1 is housed in a storage container 5. ing. A hydrogen-rich gas is supplied from the fuel processor 32 to the anode 3, and an oxidant gas is supplied from the air processor 33 to the cathode 4, which is the other reaction electrode. In the fuel cell main body 1, power generation is performed by causing an electrochemical reaction between the hydrogen-rich gas and the oxidizing gas.

The hydrogen required at the anode 3 is supplied from the fuel processor 32. The fuel processor 32 includes a reformer 5, a high-temperature carbon monoxide converter 30, and a low-temperature carbon monoxide converter 31. The reformer 5 heats a raw fuel such as natural gas to about 600-800 ° C., and forms a reforming section 5a composed of a reaction chamber for generating a hydrogen-rich gas by a steam reforming reaction, and generates heat required for the reforming reaction. It is divided into a combustion section 5b comprising a combustion chamber to be supplied.

The hydrogen-rich gas as the reformed gas exiting the reformer 5 is subjected to a shift reaction in the high-temperature carbon monoxide converter 30 and the low-temperature carbon monoxide converter 31 on the downstream side so that the carbon monoxide concentration can be reduced and the hydrogen gas can be reduced. The concentration is increased. The shift reaction occurs at about 400 ° C. in the high-temperature carbon monoxide converter 10 and at about 200 ° C. in the low-temperature carbon monoxide converter 31. The hydrogen-rich gas exiting the low-temperature carbon monoxide converter 31 is supplied to the anode 3.

Exhaust fuel containing unreacted components leaving the anode 3 is supplied to a reformer combustion chamber 5a for effective use as fuel for combustion in a combustion section 5b of the reformer 5.

On the other hand, air is usually used as the oxidizing gas supplied to the cathode 4, and air from the atmosphere is supplied to the cathode 4 via an air processing device 33. As the air processing device 33, for example, an air compression device such as a compressor or a blower can be used.

The hydrogen-rich gas discharged from the low-temperature carbon monoxide converter 31 is branched, and a part of the hydrogen-rich gas is supplied to the catalytic combustor 14 through the conduit 12a. on the other hand,
Part of the air from the air treatment device 33 is supplied to the catalytic combustion device 14.
And catalytically combusts with the hydrogen-rich gas supplied to the catalytic combustor 14. Here, the flow rates of the hydrogen-rich gas and the air are set by setting throttle means such as orifices in each line as necessary. The flue gas discharged from the catalytic combustor 34 is supplied to the conduit 1
3 and supplied to the storage container 2 as a purge gas.

Although this embodiment is an example in which the catalytic combustor 34 is used, a configuration in which a normal combustor such as a burner is used instead of the catalytic combustor 34 may be used. The same applies to the following embodiments.

Next, the operation of this embodiment will be described. The gas composition of the hydrogen-rich gas in the fuel processor 32 is substantially constant regardless of the operating state and load level of the plant, and the air composition in the atmosphere also has a constant oxygen concentration. Therefore, by constantly burning a fixed amount of the hydrogen-rich gas and a fixed amount of the air in the catalytic combustor 34, it is possible to obtain a purge gas having a substantially constant low-level oxygen concentration as the exhaust gas of the catalytic combustor 34. .

That is, the gas concentration of the hydrogen-rich gas obtained from the fuel processor 32 is substantially constant, and the oxygen concentration in the air obtained from the air processor 33 is also constant. As a result of burning a certain amount in the catalytic combustor 34, the exhaust gas discharged from the catalytic combustor 34 always has a stable low-oxidation gas composition irrespective of the plant operating state and load level. Therefore, by supplying the exhaust gas discharged from the catalytic combustor 34 to the storage container 2 as a purge gas, the storage container 2 can be stably purged.

According to the configuration of this embodiment, the catalytic combustor 34
Is provided, and the hydrogen-rich gas obtained from the fuel processor 32 and the air from the air processor 33 are burned in the catalytic combustor 34, and the combustion exhaust gas discharged from the catalytic combustor 34 is used as a purge gas as a purge gas. Purge can be performed with sufficient safety in any plant operating state by using a purge gas having a stable low oxygen concentration gas composition regardless of the operating state and load level of the plant. .

Next, an eighth embodiment of the present invention will be described with reference to FIG. In FIG. 8, the catalytic combustor 34 and the storage container 2
A cooler 35 and a brackish water separator 36 are provided between the two. FIG. 8 shows an example in which both the cooler 35 and the brackish water separator 36 are installed.
Alternatively, a condenser combining the cooler 35 and the steam separator 36 may be provided.

According to the structure of this embodiment, the same operation and effect as those of the seventh embodiment can be obtained. Further, since the cooler 35 or the brackish water separator 36 is provided, the temperature of the combustion exhaust gas from the catalytic combustor 34 can be controlled to an allowable level or lower of the temperature of the fuel cell. Although the combustion exhaust gas becomes rich in moisture, the exhaust gas is dried through the cooler 35 and the brackish water separator 36, whereby the drain clogging in the purge line can be prevented.

Next, a ninth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 9, in the present embodiment, in addition to the catalytic combustor 34, the cooler 35, and the brackish water separator 36,
A condenser 37 is provided downstream of the low-temperature carbon monoxide converter 31.

The hydrogen-rich gas discharged from the condenser 37 is sent to the anode 3 and the catalytic combustor 34 via the conduits 12d and 12e.

According to the structure of this embodiment, the hydrogen-rich gas is branched from the downstream side of the condenser 37, so that the water content in the hydrogen-rich gas is reduced. As a result, the cooler 35 and the brackish water separator 36 can be made compact. Also,
It has the same function and effect as the seventh embodiment.

The location where the hydrogen-rich gas is taken out from the combustion treatment device 32 is not limited to the downstream of the low-temperature carbon monoxide converter 31 as in the seventh and eighth embodiments. As shown in the present embodiment, it may be taken out from the downstream side of the condenser 37. Further, it may be taken out from the downstream side of the reforming section 5a of the reformer 5 on the reaction side or the downstream side of the high-temperature carbon monoxide converter 30. It may be taken out of either.

Next, a tenth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 10, this embodiment has a configuration similar to that of the eighth embodiment shown in FIG. In this embodiment, the storage container 2 is further provided from the downstream side of the brackish water separator 36.
There is provided a means for branching a part of the purge gas by the conduit 13a from before the gas enters the chamber, returning the branched purge gas to the upstream of the catalytic combustor 34 via the blower 38, and circulating the purge gas.

According to the structure of the present embodiment, the combustion temperature of the catalytic combustor 34 can be reduced by circulating the purge gas, so that the material cost of the catalytic combustor 34 can be reduced. Further, it has the same function and effect as the seventh embodiment.

Next, an eleventh embodiment of the present invention will be described with reference to FIG. In FIG. 11, there is provided means for branching a purge gas discharged from an outlet of the storage container 2 through a conduit 15a, and returning a part of the branch gas to an upstream side of the catalytic combustor 34 via a blower 38 to circulate the purge gas. I have.

According to the structure of this embodiment, the combustion temperature in the catalytic combustor 34 can be reduced by circulating the purge gas. Further, the flow rate of the purge gas supplied to the storage container 2 can be increased as compared with the tenth embodiment shown in FIG. Further, it has the same function and effect as the seventh embodiment.

Next, a twelfth embodiment of the present invention will be described with reference to FIG. In FIG. 12, a flow detecting device 39 and a control valve 4
0 is provided. A control valve 41 is provided in a line for supplying air from the air processing device 33 to the catalytic combustor 34. A gas concentration meter 42 is provided in a line of the combustion exhaust gas discharged from the catalytic combustor 34.
The flow rate detection signal measured by the flow rate detection device 39 is sent to the control device 43, and the opening of the control valve 40 is adjusted so that the detected value matches a preset flow rate set value. The detection signal of the gas concentration meter 42 is also transmitted to the control device 4.
3 and the opening of the control valve 41 is adjusted based on the detected value.

According to the configuration of this embodiment, the flow rate of the purge gas in the storage container 2 can be controlled as set, and the storage container 2 can be always purged at an appropriate flow rate. Further, it has the same function and effect as the seventh embodiment.

Next, thirteenth to sixteenth embodiments of the present invention will be described with reference to FIGS. The thirteenth to sixteenth embodiments solve the conventional problems as described below.

That is, as shown in FIG. 20, in the conventional case where the purge is performed by using an inert gas or the like as the purge gas supply source 50, the required amount of the inert gas becomes enormous in a long-term operation. In addition, there is a problem that the operation cost is increased due to the consumption of the inert gas.

The thirteenth to sixteenth embodiments will be described below. First, a thirteenth embodiment will be described with reference to FIG. In FIG. 13, the fuel cell main body 1 is hermetically housed in a storage container 2. The fuel and the oxidant that have reacted in the fuel cell main body 1 are discharged as exhausted fuel and exhausted oxidant via conduits 16 and 17. Further, a purge gas supply source 50 is provided outside the storage container 2,
Purge gas is supplied from the purge gas supply source 50 to the storage container 2 via the purge inlet pipe 52.

The purge gas supplied from the purge gas supply source 50 is air pressurized by a blower, a compressor, or a turbo compressor.

On the other hand, the purge inlet pipe 52 is provided with an oxygen removing device 51 for removing or reducing oxygen. Examples of the oxygen removing device 51 include a pressure swing adsorption method (PSA method) in which oxygen is adsorbed using an adsorbent such as molecular sieves (MOLECULAR SIEVES).

Next, the operation of this embodiment will be described. The air from the purge gas supply source 50 is sent to the oxygen removing device 51. The oxygen removing device 51 removes oxygen from the air to generate air having no or reduced oxygen components. This air is sent to the storage container 2 through the purge inlet pipe 52.

According to the structure of this embodiment, the oxygen removing device 1
Since 0 is provided, a purge gas having no or reduced oxygen component can be generated from air. As a result, it is not necessary to use an inert gas, and it is possible to provide a fuel cell power plant that does not require an operating cost.

Incidentally, as the oxygen removing device 51, an oxygen adsorbent, a chemical reactant, or a separation membrane may be used.

Next, a fourteenth embodiment of the present invention will be described with reference to FIG. In this embodiment, as shown in FIG. 14, a compressor 53 is provided as a purge gas supply source, and an oxygen adsorbing device 55 using an oxygen adsorbent such as the above-mentioned molecular sieve is provided as an oxygen removing device.
Since the air temperature is preferably set to 50 ° C. to 60 ° C. or less for oxygen adsorption, a cooler 54 is provided between the compressor 53 and the oxygen adsorption device 55. Further, the oxygen adsorbing device 55 is provided with an oxygen exhaust pipe 56 for discharging the adsorbed oxygen.

The air discharged from the compressor 53 is cooled by the cooler 54 and then sent to the oxygen adsorbing device 55. The oxygen adsorbing device 55 adsorbs and removes the oxygen in the air to generate air having no or reduced oxygen components. This air is sent to the storage container 2 through the purge inlet pipe 52. The adsorbed oxygen is discharged through the oxygen exhaust pipe 56.

According to the structure of this embodiment, the oxygen adsorbing device 5
Because of the provision of 5, it is possible to easily generate a purge gas having no or reduced oxygen component from the air. As a result, it is not necessary to use an inert gas, and it is possible to provide a fuel cell power plant that does not require an operating cost.

Next, a fifteenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a purge flow control valve 57 is provided in the purge inlet pipe 52 as shown in FIG.

In FIG. 15, the purge flow control valve 57 is installed downstream of the oxygen adsorption device 55, but it can be installed upstream. In addition, the purge flow control valve 5
Numeral 7 may be a modulating valve whose opening can be adjusted, or a shut-off valve that is only on / off.

According to the structure of this embodiment, the purge inlet pipe 5
2, the purge flow rate control valve 57 is provided, so that the purge flow rate control valve 57 is periodically or in accordance with the flammable gas concentration of the storage container 2, or in accordance with the pressure of the storage container 2, or in accordance with the pressure of the storage container 2 and the fuel. The storage container 2 can be intermittently purged by opening and closing in accordance with a pressure difference between the battery main body 1.

Next, a sixteenth embodiment of the present invention will be described with reference to FIG. In this embodiment, an accumulator tank 58 is provided downstream of the oxygen adsorbing device 55 as shown in FIG. Downstream of the tank 58, the purge inlet pipe 52 is divided into three sections 52a, 52b, and 52c. Through these purge inlet pipes 52a, 52b, 52c, a purge gas is supplied not only to the storage container 2 but also to a fuel electrode and an oxidant electrode (not shown) of the fuel cell main body 1. Further, purge gas flow control valves 59a, 59b, 59c are provided in the respective purge inlet pipes 52a, 52b, 52c. The oxygen-free or reduced air generated by the oxygen adsorbing device 55 is stored in the accumulator tank 58.

A compressor may be provided between the oxygen adsorption device 55 and the accumulator tank 58 to increase the pressure in the tank 58.

According to the configuration of this embodiment, not only the storage container 2 but also the fuel cell main body 1 can be purged by opening and closing the purge gas flow control valves 59a, 59b, 59c as required. As a result, it is possible to provide a fuel cell power plant capable of performing efficient and reliable purging.

[0102]

As described above, according to the present invention,
Since a gas separation device is provided and carbon dioxide is separated by this gas separation device and used as a purge gas, adverse effects due to combustible components and oxygen components contained in the purge gas of the storage container of the fuel cell body are removed, and the storage container is removed. Can be safely purged.

Further, since a dehumidifier is provided at the purge inlet pipe, the generation of drain can be prevented even when the exhaust gas discharged from the combustion section of the reformer is used as the purge gas.

Further, since a catalytic combustor and a dehumidifying device are provided in the purge inlet pipe, even if an excessive amount of combustion air is supplied to perform stable combustion in the combustion section of the reformer, the catalytic combustor may be used. Can be supplied to the storage container as a purge gas having a low concentration or an oxygen component-free sufficient for safety.

Further, since a catalytic combustor is provided, the hydrogen-rich gas and the air from the reformed air are combusted by the catalytic combustor, and the combustion exhaust gas is used as a purge gas. A purge gas having a stable low oxygen concentration gas composition can be obtained, and purging can be performed with sufficient safety in any plant operating state.

Further, since the oxygen removing device for removing oxygen in the air is provided, the containment vessel can be purged with air having a reduced oxygen component without using an inert gas, and the fuel cell power generation system can be operated at low cost. A plant can be provided.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a first embodiment of a fuel cell power plant according to the present invention.

FIG. 2 is a system diagram showing a second embodiment of the fuel cell power plant.

FIG. 3 is a system diagram showing a third embodiment of the fuel cell power plant.

FIG. 4 is a system diagram showing a fourth embodiment of the fuel cell power plant.

FIG. 5 is a diagram showing a fifth embodiment showing a specific configuration of a dehumidifier used for a fuel cell power plant according to the present invention.

FIG. 6 is a view showing a sixth embodiment showing another specific configuration of the dehumidifier used in the fuel cell power plant.

FIG. 7 is a system diagram showing a seventh embodiment of the fuel cell power plant according to the present invention.

FIG. 8 is a system diagram showing an eighth embodiment of the fuel cell power plant.

FIG. 9 is a system diagram showing a ninth embodiment of the fuel cell power plant.

FIG. 10 is a system diagram showing a tenth embodiment of the fuel cell power plant.

FIG. 11 is a system diagram showing an eleventh embodiment of the fuel cell power plant.

FIG. 12 is a system diagram showing a twelfth embodiment of the fuel cell power plant.

FIG. 13 is a system diagram showing a thirteenth embodiment of the fuel cell power plant.

FIG. 14 is a system diagram showing a fourteenth embodiment of the fuel cell power plant.

FIG. 15 is a system diagram showing a fifteenth embodiment of the fuel cell power plant.

FIG. 16 is a system diagram showing a sixteenth embodiment of the fuel cell power plant.

FIG. 17 is a system diagram showing a conventional fuel cell power plant.

FIG. 18 is a system diagram showing another conventional fuel cell power plant.

FIG. 19 is a system diagram showing still another conventional fuel cell power plant.

FIG. 20 is a system diagram showing another conventional fuel cell power plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell main body 2 Storage container 3 Fuel electrode 4 Oxygen agent electrode 5 Reformer 5a Reforming unit 5b Combustion unit 10 Gas separator 11 Blower 12 Duct 12a Duct 12b Duct 12c Duct 12d Duct 12e Duct 13 Duct 14 Duct 15 Duct 16 Conduit 17 Conduit 18 Conduit 19 Conduit 20 Conduit 21 Conduit 21 Purge gas inlet pipe 22 Dehumidifier 23 Blower 24 Catalytic combustor 25 Condenser 26 Steam separator 27 Heat exchanger 28 Contact cooler 30 High temperature carbon monoxide converter 31 Low temperature carbon monoxide converter Reference Signs List 32 fuel processing device 33 air processing device 34 catalytic fuel device pole 35 cooler 36 steam separator 37 condenser 38 blower 39 flow rate detection device 40 control valve 41 control valve 42 gas concentration meter 43 control device 50 purge gas 51 oxygen removing device 52 purge gas Inlet pipe 52a purge gas Inlet pipe 52b Purge gas inlet pipe 52c Purge gas inlet pipe 53 Compressor 54 Cooler 55 Oxygen adsorber 56 Oxidation exhaust pipe 57 Purge flow rate control valve 58 Accumulator tank 59a valve 59b valve 59c valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Motohiro Takahashi 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Works, Toshiba Corporation (72) Inventor Masahiro Akiyoshi 1-chome, Shibaura, Minato-ku, Tokyo No. 1-1 In the head office of Toshiba Corporation (72) Inventor Yuji Nagata 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Works, Toshiba Corporation (72) Inventor Seiji Suzuki Fuchu-shi, Tokyo 1 Toshiba-cho Toshiba Corporation Fuchu Office

Claims (3)

[Claims] 1. A fuel cell power plant comprising a fuel cell main body, a storage container for accommodating the fuel cell main body, and a reformer for generating a reformed gas to be supplied to the fuel cell main body, wherein the dehumidifier is provided. A fuel cell power plant, wherein exhaust gas discharged from the combustion section of the reformer is dehumidified by the dehumidifier and then supplied as a purge gas to the containment vessel. 2. A fuel cell power plant comprising: a fuel cell main body; a storage container accommodating the fuel cell main body; and a reformer for generating a reformed gas to be supplied to the fuel cell main body. An exhaust gas discharged from a combustion section of the reformer and a reformed gas discharged from a reforming section of the reformer in the catalytic combustor, A fuel cell power plant, wherein exhaust gas discharged from a vessel is dehumidified by the dehumidifier and then supplied to the storage container as a purge gas. 3. A fuel cell power plant having a fuel cell main body and a storage container for accommodating the fuel cell main body,
A fuel cell power plant, comprising: an oxygen removing device that removes oxygen in air; and supplying the air from which oxygen has been removed by the oxygen removing device to the containment vessel as a purge gas.