JPH05205759A - Fuel cell power plant - Google Patents

Abstract

PURPOSE:To remove surely combustible component and oxygen component in purge gas supplied to the containment vessel of the main body of a fuel cell, by providing a catalytic combustor in a power plant, burning reformed gas and oxidant in the combustor, and supplying exhaust gas emitted therefrom as purge gas to the containment vessel. CONSTITUTION:Carbon dioxide is separated from a part of gas in a conduit 12 for reformed gas system by a gas separator 10 comprising a permeable film and so on. Separated carbon dioxide is supplied to a containment vessel 2 as purge gas and purges periodically or constantly fuel and oxidant possibly remaining in the vessel, which are emitted through a conduit 15 and merged into a conduit 16 for a fuel discharge system. This constitution can eliminate bad influence due to combustible and oxygen components contained in purge gas and prevents abnormal reaction of purge gas with fuel and oxidant which are leaked from the main body 1 of the cell to the vessel 2, so as to purge the vessel 2 safely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion cell power generation plant, and more particularly to a fuel cell power generation plant for supplying a purge gas to a storage container that houses a fuel cell body.

[0002]

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

This fuel cell power plant is generally 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 is provided with a reforming section 5a consisting of a reforming tube and a combustion section 5b consisting of a burner. A mixture gas of reforming fuel and steam is introduced into the reforming section 5a to reform the gas. It 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.

The fuel cell body 1 includes a fuel electrode 3 and an oxidant electrode 4.
And is isolated from the surrounding environment by a storage container 2 that houses the fuel cell body 1.

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

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

Generally, the fuel electrode 3 and the oxidizer electrode 4 of the fuel cell body 1 are provided with sufficient gas sealing properties, but the fuel and the oxidizer are stored from the fuel cell body 1 due to aging due to long-term operation. It may leak into the container 1 and accumulate. In this case, there is a risk that an unexpected abnormal reaction may occur, and as described above, the storage container 2 is regularly or constantly purged.

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

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

[0011]

However, the exhaust gas from the combustion section 5b of the reformer 5 partially contains combustible components and oxygen components of the residual combustion. Since the combustion amount of the reformer burner varies greatly depending on the load level of the plant, these residual components generally vary depending on the load level and also during the transition period. Therefore, depending on the operating conditions of the plant, the combustible components and oxygen components of the exhaust gas exceed the reference values steadily or transiently, so that the purge gas in the storage container leaks into the fuel cell main body 1 and the oxidized fuel and oxidation. May cause dangerous reactions with chemicals.

Therefore, 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 the purge gas supplied to the storage container 2 of the fuel cell body 1, It is to provide a fuel cell power generation plant capable of safely and efficiently purging a storage container.

[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 modification for supplying the fuel cell main body. A fuel cell power plant having a reformer for producing a quality gas, comprising a gas separation device for separating carbon dioxide gas from the exhausted fuel gas or the reformed gas discharged from the fuel cell body, It is characterized in that the carbon dioxide gas separated by this gas separation device is supplied to the storage container as a purge gas.

The present invention also relates to a fuel cell power plant having 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. A dehumidifying device is provided, and the exhaust gas discharged from the combustion section of the reformer is dehumidified by the dehumidifying device and then supplied as purge gas to the storage container.

The present invention also relates to a fuel cell power plant having 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 reformer section of the reformer are burned in the catalytic combustor, and the exhaust gas discharged from the catalytic combustor is After dehumidifying with a dehumidifier, it is supplied to the storage container as a purge gas.

The present invention is also directed to a fuel cell main body, a storage container for accommodating the fuel cell main body, a reformer for generating a reformed gas to be supplied to the fuel cell main body, and an oxidant gas for the fuel cell main body. A fuel cell power plant having an oxidant gas source for supplying the reformed gas and the oxidant gas in the catalytic combustor,
The exhaust gas discharged from the catalytic combustor is supplied to the storage container as a purge gas.

Further, the present invention is a fuel cell power generation plant having a fuel cell main body and a storage container accommodating the fuel cell main body, which is provided with an oxygen removing device for removing oxygen in the air. The air from which oxygen is removed is supplied to the storage container as a purge gas.

[0018]

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

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

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 dehumidified by the dehumidifier and then supplied as purge gas to the storage container.

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

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

[0023]

EXAMPLE An example of a fuel cell power plant according to the present invention will be described below with reference to FIGS.

A first embodiment of the fuel cell power plant according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 is a fuel cell main body which causes an electrochemical reaction to generate an electric current, and the fuel cell main body 1 is housed in a storage container 2. The fuel cell body 1 includes a fuel electrode 3 and an oxidant electrode 4 which are porous electrodes.
Are sandwiched by an electrolyte (not shown). A hydrogen-rich gas produced by reforming methane gas or the like is externally supplied as a fuel to the fuel electrode 3 through a conduit 12, and oxygen is externally supplied as an oxidant to the oxidizer electrode 4 through a conduit 14.

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

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

The gas separation device 5 may be any chemical, physical or other separation system including a separation membrane.

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 separator 10 such as a permeable membrane. The separated carbon dioxide is supplied to the storage container 2 as a purge gas, and the fuel and the oxidant that may remain in the storage container 2 are regularly or constantly purged. The purge gas is discharged through the conduit 15 and joins the conduit 16 of the exhaust fuel system.

According to the configuration of this embodiment, since the gas separating device 10 for separating carbon dioxide is provided, the gas separating device 10 can separate carbon dioxide from a part of the reformed gas. Then, by supplying this carbon dioxide to the storage container 2 as a purge gas, it is possible to remove the adverse effects of the flammable components, oxygen components, etc. contained in the purge gas. As a result, it is possible to prevent the purge gas from abnormally reacting with the fuel and the oxidant that have leaked into the storage container from the fuel cell main body 1 to cause a danger, and to safely purge the storage container 2.

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
Part of the exhaust fuel discharged from the conduit 16 through the conduit 16
It is supplied to the blower 14 through a. After the pressure is increased by the blower 14, the exhaust fuel is supplied to the gas separation device 10 through the conduit 18 to separate carbon dioxide. The gas separator 10 and the subsequent components are 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 efficiently generated.

In each of the first and second embodiments, the purge gas discharged from the container 2 joins the conduit 16 of the exhaust fuel system through the conduit 15, but the conduit 17 of the exhaust air system. It may be combined with the above, or may be released from 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 exhaust fuel from the fuel electrode 3 supplied to the combustion section 5b of the reformer 5 is hydrogen, the combustion exhaust gas of the combustion section 5b generally has a water content of 10 to 10.
It is as high as 20%. When such a gas is used as the purge gas for the body storage container 2 of the fuel cell main body 1, as shown in FIG. 18, heat in the purge gas inlet pipe 21 or the storage container 2 is locally radiated to easily condense water in the gas and cause a drainage. There was a problem that it occurred.

For example, assuming that the operating pressure in the system is 5 ata, which is a general value in such a plant, the water partial pressure of 20% in the purge gas is 1 ata.
This corresponds to a saturation pressure of 0 ° C. That is, if there is a portion of the purge gas inlet pipe 21 or the containment vessel 2 at a temperature of 100 ° C. or lower, drainage will occur there.

The generation of drain 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
When the purge gas flow disappears due to the drain blockage at 1, there is a safety problem of the fuel cell body.

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

The third to sixth embodiments of the present invention will be described below.

First, a third embodiment of the present invention will be described with reference to FIG.

In FIG. 3, the fuel cell main body 1 comprises a fuel electrode 3 and an oxidant electrode 4 as an air electrode, and is further housed to store the fuel cell main body 1 and isolate it from the surrounding environment. A container 2 is provided. Since an electromotive force is generated between the fuel electrode 3 and the air electrode 4 during the power generation operation of the fuel cell,
In general, the fuel cell main body 1 which is a laminated body of these is at 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, and reforming fuel such as natural gas or methanol is supplied to the reforming section 5a through a conduit 19 together with steam, so that the steam is reformed to produce hydrogen-rich gas. Reformed gas is generated. This reformed gas is further supplied to the fuel electrode 3 through the conduit 12. In the fuel cell main body 1, after the reformed gas reacts with the air supplied to the air electrode 4 through the conduit 14 as an oxidant, the remaining portions not consumed are exhausted fuel and exhausted air, 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 the amount of reforming heat for steam reforming, but is used for the combustor 5b in order to improve the efficiency of the fuel cell plant. Exhaust fuel from the fuel electrode 3 is supplied as fuel through the conduit 16a. Combustion air in the combustion section 5b is supplied by the conduit 14a. Exhaust gas burned in the combustion section 5b is discharged to the outside of the system through the conduit 20, but a part of the exhaust gas is introduced 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 blower 11 above the first container 1 and passing through the storage container 1 c is discharged through the conduit 12.

The process up to this point is the same as in the conventional fuel cell power plant shown in FIG.

A feature of this embodiment is that the purge gas inlet pipe 21 is provided with a dehumidifying device 22.

As a concrete example of the structure of the dehumidifier 22,
A chemical water absorbent, a water absorbent, or a water separation membrane can be applied.

Next, the operation of this embodiment will be described.

A part of the exhaust gas of the combustion section 5b supplied to the storage container 2 as the purge gas is circulated to the dehumidifier 22.
Since the moisture content of the exhaust gas flowing through the dehumidifying device 20 decreases, it is possible to prevent the generation of a large amount of drain.

By appropriately selecting the dehumidifying level of the dehumidifying device 22, the moisture saturation temperature in the purge gas can be lowered to room temperature or lower. In this case, even if the purge gas inlet pipe 21, the blower 23, or a part or the whole of the storage container 2 has a temperature drop due to heat radiation, drainage does not occur. As a result, it is possible to prevent the generation of drain in the purge gas.

According to the structure of this embodiment, since the dehumidifying device 22 is provided in the purge gas inlet pipe 21, it is possible to eliminate the risk of drain clogging in the purge gas inlet pipe 10 and drain attack to the blower 23.
Furthermore, there is no possibility of causing insulation failure due to condensed water inside the storage container 2.

As a result, it is possible to provide a fuel cell power plant that can realize high reliability.

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

In FIG. 4, the purge inlet pipe 21 is provided with a catalytic combustor 24 and a dehumidifying device 22 downstream of the catalytic combustor 24.

A part of the exhaust gas discharged from the combustion section 5b of the reformer 5 is supplied to the catalytic combustor 24 through the conduit 21. 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.
Then, 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 exhaust fuel from the fuel electrode 3 of the fuel cell body 1 as the fuel for combustion in the catalytic combustor 24.

Exhaust gas discharged from the catalyst combustor 24 is supplied as a purge gas to the storage container 2 of the fuel cell main body 1 through the dehumidifying device 22 and the blower 23.

Next, the operation of this embodiment will be described.

In general, in a fuel cell power plant, in order to use a part of the exhaust gas discharged from the combustion section 5b of the reformer 5 as a purge gas for the containment vessel 2, it is desirable that the residual oxygen concentration in the exhaust gas is as small as possible.

On the other hand, the amount of combustion in the combustion section 5b greatly differs depending on the load level of the plant and also changes due to a transient change. Therefore, in order to always perform stable combustion in the combustion section 5b, the air for combustion is supplied to the conduit 1
It may be necessary to supply an excessive amount through 4a.

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

As shown in FIG. 4, in the present embodiment, the purge gas inlet pipe 21 is provided with a catalytic combustor 24 to remove residual oxygen components in the exhaust gas discharged from the combustion section 5b of the reformer 5 by the catalytic combustor 24. Consume at. As a result, the exhaust gas discharged from the catalytic combustor 24 is stored in the storage container 2 as a purge gas containing a low concentration or oxygen component that is sufficiently safe for safety.
Can be supplied to.

In this case, the catalytic combustor 24
The water produced by the reaction in step 1 adds to the exhaust gas. Therefore, the moisture content in the exhaust gas discharged from the catalytic combustor 24 becomes higher than the moisture content in the exhaust gas from the combustion section 5b of the reformer, further increasing the risk of drainage. However, in the present embodiment, since the dehumidifying device 22 is provided on the downstream side of the catalytic combustor 24, it is possible to reduce the moisture content in the purge gas that has left the dehumidifying device 22. This makes it possible to prevent the generation of drain in the purge gas.

According to the structure of this embodiment, the purge inlet pipe 21 is provided with the catalytic combustor 24 and the dehumidifying device 22 on the downstream side of the catalytic combustor 24, so that the combustion section 5b of the reformer 5 is stable. In order to perform combustion, air for combustion is supplied to the conduit 14a.
Even if it is supplied in an excessive amount through the catalytic combustor 2
It is possible to supply the exhaust gas discharged from No. 4 to the storage container 2 as a purge gas that has a sufficiently low concentration for safety and does not contain an oxygen component. Further, in this case, even if the purge gas inlet pipe 21 is provided with the catalytic combustor 24, since the dehumidifying device 22 is provided on the downstream side, an adverse effect due to drain may occur inside the pipe portion, the blower 23, or the storage container 2. Absent. As a result, it is possible to provide a fuel cell power generation plant that can realize high reliability.

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

FIG. 5 shows another concrete configuration example of the dehumidifying device 22 in the fuel cell power plant according to the present invention. In FIG. 5, the purge gas is supplied to the condenser 25 and the steam separator 2.
6. The moisture in the gas is removed by flowing the heat exchanger 27. The purging waste is a condenser 25
After being cooled by and drain-separated by the steam separator 26,
It is reheated in the heat exchanger 27 and sent as superheated gas.
Therefore, there is no risk of drainage on the downstream side.

By using the structure of the dehumidifier 22 as described above, 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 dehumidifying device 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 drain-separated by the contact cooler 28, reheated by the heat exchanger 27, and sent as superheated gas.

By using the structure of the dehumidifier 22 as described above, the same effects as those of the third and fourth embodiments can be obtained.

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

That is, in the conventional fuel cell power generation 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, reforming is performed depending on various operating conditions of the plant. Since the combustion amount of the device 5 is greatly different, the oxygen concentration in the flue gas is not always constant, and in particular varies greatly depending on the load level and transient changes. For this reason, the oxygen concentration in the purge gas of the storage container 2 fluctuates greatly, and if the oxygen concentration exceeds a certain level due to this fluctuation, it is impossible to always safely purge the battery container. there were.

The seventh to twelfth embodiments of the present invention will be described below.

First, a seventh embodiment will be described with reference to FIG. In FIG. 7, the fuel cell body 1 includes a fuel electrode 3 that is an anode electrode, an oxygen agent electrode 4 that is a cathode electrode, and a cell stack body in which these are stacked. The fuel cell body 1 is housed in a storage container 5. ing. A hydrogen-rich gas is supplied from the fuel processing device 32 to the anode electrode 3, and an oxidant gas is supplied from the air processing device 33 to the cathode electrode 4, which is the other reaction electrode. In the fuel cell main body 1, the hydrogen-rich gas and the oxidant gas cause an electrochemical reaction to generate power.

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

The hydrogen-rich gas as the reformed gas, which has flowed out of the reformer 5, is reduced in the concentration of carbon monoxide by the shift reaction in the high-temperature carbon monoxide shift converter 30 and the low-temperature carbon monoxide shift converter 31 which are located downstream. The concentration is increased. The shift reaction occurs at about 400 ° C. in the high temperature carbon monoxide shift converter 10 and at about 200 ° C. in the low temperature carbon monoxide shift converter 31. The hydrogen-rich gas leaving the low temperature carbon monoxide shift converter 31 is supplied to the anode 3.

The exhaust fuel containing the unreacted components that has exited from the anode electrode 3 is supplied to the reformer combustion chamber 5a in order to be effectively used as the fuel for combustion in the combustion section 5b of the reformer 5.

On the other hand, air is usually used as the oxidant gas supplied to the cathode 4, and air from the atmosphere is supplied to the cathode 4 via the air treatment device 33. As the air treatment 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 shift 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 the catalytic combustion device 14
And the hydrogen-rich gas supplied to the catalytic combustor 14 is catalytically combusted. Here, the flow rates of the hydrogen rich gas and the air are set by setting throttling means such as an orifice in each line as needed. The combustion exhaust gas discharged from the catalytic combustor 34 is the conduit 1
It is supplied to the storage container 2 as a purge gas through the storage container 3.

In this embodiment, the catalytic combustor 34 is used as an example. However, instead of the catalytic combustor 34, an ordinary combustor such as a burner may be used. The same applies to the following examples.

Next, the operation of this embodiment will be described.

The gas composition of the hydrogen-rich gas in the fuel processor 32 is almost constant regardless of the operating condition and load level of the plant, and the air composition in the atmosphere also has a constant oxygen concentration. Therefore, a fixed amount of hydrogen-rich gas and a fixed amount of air are constantly supplied to the catalytic combustor 34.
By combusting in (1), a purge gas having an almost constant low level oxygen concentration can be obtained as the exhaust gas of the catalytic combustor 34.

That is, since the gas concentration of the hydrogen-rich gas obtained from the fuel processing device 32 is almost constant, and the oxygen concentration in the air obtained from the air processing device 33 is also constant, the hydrogen-rich gas and the air, respectively. 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 concentration gas composition regardless of the operating state of the plant or the load level. Therefore, by supplying the exhaust gas discharged from the catalyst 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
In addition, the hydrogen rich gas obtained from the fuel processing device 32 and the air from the air processing device 33 are combusted in the catalytic combustor 34, and the combustion exhaust gas discharged from the catalytic combustor 34 is used as a purge gas in the storage container 2 Therefore, regardless of the operating condition and load level of the plant, the purge gas having a stable low oxygen concentration gas composition can always be used for purging with sufficient safety in any operating condition of the plant. ..

Next, an eighth embodiment of the present invention will be described with reference to FIG.

In FIG. 8, a cooler 35 and a brackish water separator 36 are installed between the catalytic combustor 34 and the containment vessel 2. Although FIG. 8 shows an example in which both the cooler 35 and the brackish water separator 36 are installed, in the case of only the cooler 35,
Alternatively, a condenser in which the cooler 35 and the brackish water separator 36 are combined may be provided.

According to the configuration of this embodiment, the same operational effect as that of the seventh embodiment is 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 be equal to or lower than the allowable level of the temperature of the fuel cell. Further, although the combustion exhaust gas becomes rich in water, it is possible to prevent drain clogging in the purge line by drying the combustion exhaust gas through the cooler 35 and the brackish water separator 36.

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

As shown in FIG. 9, in this 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 shifter 31. There is.

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

According to the configuration 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 effects as the seventh embodiment.

The place 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 shift converter 31 as in the seventh and eighth embodiments, and is shown in FIG. It may be taken out from the downstream side of the condenser 37 as in this embodiment shown, and further, such as the downstream side of the reaction side of the reforming section 5a of the reformer 5 or the downstream side of the high temperature carbon monoxide shift converter 30. It may be taken out from 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 structure similar to that of the eighth embodiment shown in FIG. In the present embodiment, a part of the purge gas is further branched by the conduit 13a from the downstream side of the brackish water separator 36 until it enters the containment vessel 2, and the branched purge gas is upstream of the catalytic combustor 34 via the blower 38. And means for circulating the purge gas.

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

Next, an eleventh embodiment of the present invention will be described with reference to FIG.

In FIG. 11, the purge gas discharged from the outlet of the containment vessel 2 is branched by the conduit 15a, a part of which is returned to the upstream side of the catalytic combustor 34 via the blower 38 to circulate the purge gas. It is provided.

According to the configuration of this embodiment, the combustion temperature in the catalytic combustor 34 can be lowered 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 effect as that of the seventh embodiment.

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

In FIG. 12, the low temperature carbon monoxide transformer 3
1. The hydrogen-rich gas is branched from the downstream side of the catalyst combustor 3
4, a flow rate detection device 39 and a control valve 40
Is provided. A control valve 41 is provided in the line that supplies air from the air treatment device 33 to the catalytic combustor 34. A gas concentration meter 42 is provided in the combustion exhaust gas line 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 degree of the control valve 40 is adjusted so that the detected value matches the preset flow rate setting value. Further, the detection signal of the gas concentration meter 42 is also controlled by the control device 43.
And the opening of the control valve 41 is adjusted by 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 according to the set value, and the storage container 2 can always be purged at an appropriate flow rate. Further, it has the same effect as that of 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 in which the purge gas supply source 50 is purged by using an inert gas or the like, the required amount of the inert gas becomes enormous in a long-term operation. Then, there is a problem that operating costs are increased due to consumption of the inert gas.

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 a storage container 2
It is housed in a closed room. In addition, the fuel cell body 1
The fuel and oxidant reacted in the conduits 16 and 17
Is discharged as exhaust fuel and exhaust oxidant. A purge gas supply source 50 is provided outside the storage container 2, and the 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 the air whose pressure is increased by the blower, the compressor or the 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) that adsorbs oxygen 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 in the air to generate air having no oxygen component or reduced air. This air is the purge inlet pipe 52.
And is sent to the storage container 2.

According to the configuration of this embodiment, the oxygen removing device 1
Since 0 is provided, a purge gas free of oxygen components or reduced in purge gas can be generated from air. As a result, it is possible to provide a fuel cell power generation plant that does not require the use of an inert gas and does not require operating costs.

As the oxygen removing device 51, an oxygen adsorbent, a chemical reaction agent, 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 sieves is provided as an oxygen removing device. Further, since it is preferable to set the air temperature to 50 ° C. to 60 ° C. or less for adsorbing oxygen, a cooler 54 is provided between the compressor 53 and the oxygen adsorbing device 55. Further, the oxygen adsorption device 55 is provided with an oxygen exhaust pipe 56 for exhausting the adsorbed oxygen.

The air discharged from the compressor 53 is cooled by the cooler 54 and then sent to the oxygen adsorption device 55. In the oxygen adsorbing device 55, air in the air is adsorbed and eliminated to generate air having no or reduced oxygen component. 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 configuration of this embodiment, the oxygen adsorption device 5
Since 5 is provided, it is possible to easily generate an oxygen-free or reduced purge gas from the air. As a result, it is possible to provide a fuel cell power generation plant that does not require the use of an inert gas and does not require operating costs.

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

In this embodiment, as shown in FIG. 15, the purge inlet pipe 52 is provided with a purge flow rate control valve 57.

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

According to the configuration of this embodiment, the purge inlet pipe 5
2 is provided with a purge flow rate control valve 57, the purge flow rate control valve 57 is provided periodically, according to the combustible gas concentration of the storage container 2, or according to the pressure of the storage container 2, or with the storage container 2 and the fuel. The storage container 2 can be intermittently purged by opening and closing according to the pressure difference with the battery body 1.

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

In this embodiment, as shown in FIG. 16, an accumulator tank 58 is provided downstream of the oxygen adsorbing device 55. Downstream of the tank 58, the purge inlet pipe 52 is divided into three parts 52a, 52b and 52c.
Through these purge inlet pipes 52a, 52b and 52c, the purge gas is supplied to the storage container 2 as well as the fuel electrode and the oxidant electrode (not shown) of the fuel cell body 1. Further, purge gas flow rate adjusting valves 59a, 59b, 59c are provided on the respective purge inlet pipes 52a, 52b, 52c. The oxygen-free or reduced-air produced 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 of the tank 58.

According to the structure of this embodiment, not only the storage container 2 but also the fuel cell body 1 can be purged by opening and closing the purge gas flow rate adjusting valves 59a, 59b, 59c as necessary. As a result, it is possible to provide a fuel cell power generation plant that can perform efficient and reliable purging.

[0122]

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, the adverse effect of flammable components and oxygen components contained in the purge gas of the containment vessel of the fuel cell main body is removed and the containment vessel is removed. Can be safely purged.

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

Further, since the purge inlet pipe is provided with the catalytic combustor and the dehumidifying device, even if the combustion air is excessively supplied in order to perform stable combustion in the combustion section of the reformer, the catalytic combustor is not provided. It is possible to supply the exhaust gas discharged from the storage container to the storage container as a purge gas that has a sufficiently low concentration or oxygen component that is safe for safety.

Further, since the catalytic combustor is provided and the hydrogen-rich gas from the reformed gas and the air are combusted in the catalytic combustor and this combustion exhaust gas is used as the purge gas, regardless of the operating state of the plant or the load level, It is possible to obtain a purge gas having a stable gas composition with a low oxygen concentration, and it is possible to perform purge while ensuring 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 the air having a reduced oxygen component without using an inert gas, and the fuel cell power generation can be performed at a low operating cost. A plant can be provided.

[Brief description of 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 the specific configuration of the dehumidifying device used in the fuel cell power plant according to the present invention.

FIG. 6 is a diagram showing a sixth embodiment showing another specific configuration of the dehumidifying device 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 generation plant.

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

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

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

[Explanation of symbols]

 1 Fuel Cell Main Body 2 Containment Vessel 4 Fuel Electrode 4 Oxygen Agent Electrode 5 Reformer 5a Reforming Section 5b Combustion Section 10 Gas Separation Device 11 Blower 12 Conduit 12a Conduit 12b Conduit 12c Conduit 12d Conduit 12e Conduit 13 Conduit 14 Conduit 15 Conduit 16 Conduit 17 Conduit 18 Conduit 19 Conduit 20 Conduit 21 Purge gas inlet pipe 22 Dehumidifier 23 Blower 24 Catalytic combustor 25 Condenser 26 Brackish water separator 27 Heat exchanger 28 Contact cooler 30 High temperature carbon monoxide converter 31 Low temperature carbon monoxide converter 32 Fuel treatment device 33 Air treatment device 34 Catalyst fuel device pole 35 Cooler 36 Brackish water 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 removal 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 adsorption device 56 Oxidation exhaust pipe 57 Purge flow control valve 58 Accumulator tank 59a valve 59b valve 59c valve

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masahiro Akiyoshi 1-1-1 Shibaura, Minato-ku, Tokyo Inside Toshiba Headquarters office (72) Inventor Yuji Nagata 1 share in Toshiba Town, Fuchu-shi, Tokyo Company Toshiba Fuchu Factory (72) Inventor Yoshiyuki Suzuki Fuchu City, Tokyo 1

Claims (5)

[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. A gas separation device for separating carbon dioxide gas from the exhausted fuel gas or the reformed gas discharged from the battery body is provided, and the carbon dioxide gas separated by the gas separation device is supplied to the storage container as a purge gas. And a fuel cell power plant. 2. 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. A fuel cell power plant, comprising: a dehumidifying device for dehumidifying exhaust gas discharged from the combustion section of the reformer, and then supplying the gas as purge gas to the storage container. 3. A fuel cell power plant having 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. A reformer 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 catalytic combustion is performed. A fuel cell power plant, wherein exhaust gas discharged from a reactor is dehumidified by the dehumidifying device and then supplied as purge gas to the storage container. 4. A fuel cell main body, a container for accommodating the fuel cell main body, a reformer for generating a reformed gas to be supplied to the fuel cell main body, and an oxidant gas to the fuel cell main body. A fuel cell power plant having an oxidant gas source, comprising a catalytic combustor, burning the reformed gas and the oxidant gas in the catalytic combustor, and purging exhaust gas discharged from the catalytic combustor as a purge gas. As a fuel cell power plant. 5. A fuel cell power plant having a fuel cell body and a container for housing the fuel cell body,
A fuel cell power plant, comprising an oxygen removing device for removing oxygen in air, and supplying the air from which oxygen has been removed by the oxygen removing device as purge gas to the storage container.