JPH08124589A - Fuel cell generating equipment - Google Patents

Abstract

PURPOSE: To provide a fuel cell generating equipment capable of avoiding as far as possible a bad influence given to performance of a plant, of an electrolyte or electrolytic compound, to reduce a frequency and time of stopping the plant so as to improve its operating reliability, maintainability and availability factor. CONSTITUTION: A water injection nozzle 12 is provided in a tilt part 11a of a gas pipe 11 arranged in a part in the downstream of a fuel cell main unit. A water supply pipe 13 and a water supply valve 14 are connected to the water injection nozzle 12. Water is always supplied to the water supply pipe 13. The water supply valve 14, placed ordinarily in a closed condition, is periodically and automatically opened to supply water to the water injection nozzle 12. A drain pot 15 of temporarily storing water is provided in a lower end part in a vertical part 11b of the gas pipe 11. Under the drain pot 15, a drain discharge pipe 16 and a drain valve 17 are provided, and by opening the drain valve 17, water accumulated in the pot 15 is discharged to a drain 18. Accordingly, an electrolyte or the like sticking to inside an equipment can be taken out during operating a cell.

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 generation facility for generating electricity by an electrochemical reaction between a fuel electrode and an oxidizer electrode, and more particularly to a phosphoric acid fuel cell power generation facility using phosphoric acid as an electrolyte. Regarding

[0002]

2. Description of the Related Art Basically, a fuel cell power generation facility includes a fuel cell body composed of a fuel electrode and an oxidant electrode, a fuel gas circulation system for circulating a fuel gas and an oxidant gas to the fuel electrode and an oxidant electrode, Equipped with an oxidant gas circulation system. FIG. 5 shows such a fuel cell power generation facility,
It is a figure which shows the prior art example of the phosphoric acid type fuel cell power generation equipment which uses phosphoric acid as an electrolyte of a fuel cell main body, 1 is an anode (fuel electrode), 2 is a cathode (oxidizer electrode), 3 is an anode 1 and a cathode. 2, a fuel cell main body composed of 2, a fuel gas circulation system for circulating a fuel gas to the anode 1,
Reference numeral 5 denotes an oxidant gas circulation system for circulating the oxidant gas to the cathode 2.

First, the fuel gas circulation system 4 includes a fuel gas supply pipe 4a, an anode 1, and a fuel gas recovery pipe 4.
b, a fuel gas circulation pipe 4c, and a fuel gas combustion pipe 4d. Of these, the fuel gas supply pipe 4a is a pipe for supplying the fuel gas to the anode 1, and is connected to the inlet of the anode 1 at its downstream end. The fuel gas supply pipe 4a includes a reformer 6 for reforming the fuel gas into a gas containing hydrogen as a main component. The fuel gas recovery pipe 4b is a pipe for recovering the fuel gas used in the anode 1, and its upstream end is connected to the outlet of the anode 1.

Further, the fuel gas circulation pipe 4c is a pipe for flowing the fuel gas recovered by the fuel gas recovery pipe 4b into the fuel gas supply pipe 4a as it is, and the downstream end of the fuel gas recovery pipe 4b. And fuel gas supply pipe 4
It is connected to the upstream part of a. The fuel gas circulation pipe 4c includes a fuel gas strainer 7 including a wire mesh (element) for removing water in the fuel gas, a fuel gas circulation blower 8 for forcibly driving the fuel gas, and A heat exchanger (not shown) is provided. On the other hand, the fuel gas combustion pipe 4d is connected to the fuel gas recovery pipe 4
It is a pipe for sending a part of the fuel gas recovered in b to the burner 6a of the reformer 6 and reusing it as combustion gas. At the downstream end of the fuel gas recovery pipe 4b, from the fuel gas circulation pipe 4c. It is connected in a branched manner.

Next, the oxidant gas circulation system 5 includes an oxidant gas supply pipe 5a, a cathode 2, an oxidant gas recovery pipe 5b, an oxidant gas circulation pipe 5c, and an oxidant gas combustion pipe 5d. It consists of Of these, the oxidant gas supply pipe 5a is a pipe for supplying the oxidant gas to the cathode 2, and is connected to the inlet of the cathode 2 at its downstream end. Also, the oxidant gas recovery pipe 5b
Is a pipe for collecting the oxidant gas used in the cathode 2, and is connected to the outlet of the cathode 2 at its upstream end.

Further, the oxidant gas circulation pipe 5c is a pipe for flowing the oxidant gas recovered by the oxidant gas recovery pipe 5b into the oxidant gas supply pipe 5a as it is, and is for recovering the oxidant gas. It is connected between the downstream end of the pipe 5b and the upstream portion of the oxidant gas supply pipe 5a. The oxidant gas circulation pipe 5c includes an oxidant gas strainer 9 including a wire mesh (element) for removing water in the oxidant gas, and an oxidant gas circulation for forcibly driving the oxidant gas. The blower 10 and a heat exchanger (not shown) are provided. On the other hand, oxidant gas combustion pipe 5d
Is a pipe for sending a part of the oxidant gas recovered by the oxidant gas recovery pipe 5b to the burner 6a of the reformer 6 and reusing it as combustion gas.
Is connected to the downstream end of the pipe in a form branched from the oxidant gas circulation pipe 5c.

During operation of the phosphoric acid fuel cell power generation facility having the above-described structure, a fuel gas such as natural gas is supplied to the anode 1 by the fuel gas circulation system 4 and an oxidant gas such as air is generated. It is supplied to the cathode 2 by the oxidant gas circulation system 5. That is, the fuel gas is the fuel gas supply pipe 4 a of the fuel gas circulation system 4.
Is supplied to the anode 1, reformed into a gas containing hydrogen as a main component in the reformer 6, and then sent to the anode 1 for use in an electrochemical reaction in the fuel cell body 3. Then, the used fuel gas in the fuel cell main body 3 is recovered by the fuel gas recovery pipe 4b, and a part thereof is supplied again to the fuel gas supply pipe 4a by the fuel gas circulation pipe 4c. Also,
The rest of the used fuel gas in the fuel cell body 3 is sent to the burner 6a of the reformer 6 through the fuel gas combustion pipe 4d and burned, and becomes an energy source for hydrogen generation.

On the other hand, the oxidant gas is sent to the cathode 2 through the oxidant gas supply pipe 5a of the oxidant gas circulation system 5 and used for the electrochemical reaction in the fuel cell body 3. Then, the used oxidant gas is recovered by the oxidant gas recovery pipe 5b, and a part of the oxidant gas is recovered again by the oxidant gas circulation pipe 5c.
Is supplied to. In addition, the remainder of the used oxidant gas in the fuel cell body 3 is sent to the burner 6a of the reformer 6 through the oxidant gas combustion pipe 5d and burned to serve as an energy source for hydrogen generation.

[0009]

However, the conventional fuel cell power generation equipment having the above structure has the following problems. That is, along with the operation of the fuel cell power generation facility, part of the electrolyte such as phosphoric acid contained in the fuel cell body travels downstream in the form of vapor or fine droplets along with the flow of gas, and the inner surface of the pipe and It adheres to the wire mesh (element) of the strainer and the inside of the heat exchanger. The attached electrolyte reacts with the material of the pipes and equipment to form an electrolyte compound such as a phosphoric acid compound and attaches to the inside of the piping and equipment. For example, if an electrolyte or an electrolyte compound is deposited and adhered to the inside of a wire mesh of a strainer or a heat exchanger, and further deposited, it will be a factor of increasing the pressure loss of the system or reducing the performance of the plant. Therefore, whenever such a situation occurs, the plant will be shut down and the equipment, piping, etc.
Cleaning work is required. However, disassembling and cleaning work like this takes a long time, which reduces maintainability and
Maintenance cost will increase. Further, as the disassembling / cleaning work becomes longer, the plant downtime becomes longer, so that the operating rate of the plant is reduced and the stable supply of electric power is hindered.

The present invention has been proposed in order to solve the above problems of the prior art, and its purpose is to:
It is possible to avoid the adverse effect of the electrolyte or the electrolyte compound on the performance of the plant as much as possible, reduce the frequency and time of shutting down the plant, and improve the operation reliability, maintainability, and
And to provide a fuel cell power generation facility with a high operating rate.

More specifically, an object of the invention of claim 1 is to remove an electrolyte or an electrolyte compound deposited / adhered to a downstream portion of a fuel cell main body in a fuel gas circulation system or an oxidant gas circulation system, By discharging to the outside of the system, the adverse effect of the electrolyte or the electrolyte compound on the performance of the plant at the downstream of the target site to be injected is avoided as much as possible.

An object of the present invention is to remove the electrolyte or electrolyte compound deposited / adhered inside the pipe on the downstream side of the fuel cell main body in the fuel gas circulation system or the oxidant gas circulation system, and discharge it to the outside of the system. By doing so, it is possible to avoid the adverse effect of the electrolyte or the electrolyte compound on the performance of the plant downstream of the target site to be injected.

A third object of the present invention is to intentionally deposit and deposit an electrolyte or an electrolyte compound in the electrolyte deposition / adhesion region on the downstream side of the fuel cell body in the fuel gas circulation system or the oxidant gas circulation system. , Easily and surely removes the deposited or adhered electrolyte or electrolyte compound,
By discharging to the outside of the system, the adverse effect of the electrolyte or the electrolyte compound on the plant performance downstream of the electrolyte deposition / adhesion region is to be avoided as much as possible.

An object of the invention of claim 4 is to intentionally deposit and adhere an electrolyte or an electrolyte compound in a low temperature region, and to easily and surely remove the deposited or adhered electrolyte or electrolyte compound, and to bring it to the outside of the system. By discharging
It is to avoid as much as possible the adverse effect of the electrolyte or the electrolyte compound on the plant performance downstream of the low temperature region.

An object of the invention of claim 5 is to intentionally deposit and deposit an electrolyte or an electrolyte compound on a wire mesh of a strainer, and to easily and surely remove the deposited or attached electrolyte or electrolyte compound, and Is to avoid the adverse effect of the electrolyte or the electrolyte compound on the plant performance downstream of the strainer as much as possible.

A sixth object of the present invention is to intentionally deposit and deposit an electrolyte or an electrolyte compound inside a heat exchanger, and to easily and surely remove the deposited and attached electrolyte or electrolyte compound. By discharging the heat to the outside of the system, the adverse effect of the electrolyte or the electrolyte compound downstream of the heat exchanger and the heat exchanger on the plant performance is avoided as much as possible.

An object of the present invention is to intentionally deposit and deposit an electrolyte or an electrolyte compound on a mesh member or a fibrous member, and to easily and surely remove the deposited or attached electrolyte or electrolyte compound. By discharging to the outside of the system, the adverse effect of the electrolyte or the electrolyte compound on the plant performance downstream of the mesh member or the fibrous member is to be avoided as much as possible.

An object of the present invention is to keep the influence of the electrolyte or the electrolyte compound inside the system at a certain level or below for a long period of time. An object of the invention according to claim 9 is to improve practicality by using water. It is an object of the invention of claim 10 to further improve the practicality, prevent corrosion of a target portion to which water is sprayed as much as possible, and further physically and efficiently remove an electrolyte or an electrolyte compound. Claim 1
An object of the invention described in item 1 is to chemically and efficiently remove an electrolyte or an electrolyte compound by using a liquid other than water.

[0019]

In a fuel cell power generation facility according to the present invention, a fuel cell body comprising a fuel electrode and an oxidant electrode, and a fuel gas and an oxidant gas are supplied to the fuel electrode and the oxidant electrode of the fuel cell body. In a fuel cell power generation facility that has a fuel gas circulation system and an oxidant gas circulation system that circulate respectively, and generates electricity by an electrochemical reaction between the fuel electrode and the oxidant electrode, the fuel gas circulation system or the oxidant gas circulation system is as follows. It is characterized by being configured in.

According to a first aspect of the present invention, liquid injection means for injecting a liquid into the system is provided in a portion of the fuel gas circulation system or the oxidant gas circulation system on the downstream side of the fuel cell main body, and the liquid injection means injects the liquid. Liquid recovery means for recovering the collected liquid and discharging it to the outside of the system are provided.

The invention described in claim 2 is characterized by further having the following structure in addition to the structure of the invention described in claim 1. That is, in the second aspect of the invention, the liquid injection means and the liquid recovery means are provided inside the pipe on the downstream side of the fuel cell main body of the fuel gas circulation system or the oxidant gas circulation system.

The invention described in claim 3 is characterized in that it has the following structure in addition to the structure of the invention described in claim 1. That is, in the third aspect of the invention, an electrolyte adhesion / precipitation region for intensively depositing or depositing an electrolyte or an electrolyte compound is provided on a portion of the fuel gas circulation system or the oxidant gas circulation system on the downstream side of the fuel cell body. It is provided. Then, the liquid ejecting means is configured to eject the liquid into the electrolyte deposition / adhesion region.

The invention described in claims 4 to 7 is characterized in that, in the configuration of the invention described in claim 3, the electrolyte deposition / adhesion region is configured as follows. In the invention according to claim 4, the electrolyte deposition / adhesion region is configured as a low temperature region having a temperature lower than the temperature of the fuel gas or the oxidant gas flowing into this region. In the invention according to claim 5, a strainer having a wire mesh is inserted in the electrolyte deposition / adhesion region. In the invention of claim 6, the electrolyte deposition / adhesion region is formed inside the heat exchanger. In the invention according to claim 7, electrolyte deposition
A mesh member or a fibrous member made of a material having corrosion resistance to an electrolyte is inserted in the adhesion region.

The invention described in claims 8 to 11 is characterized in that, in the configuration of the invention described in claim 1, the liquid ejecting means or its peripheral portion is constructed as follows. According to the invention described in claim 8, a liquid supply valve for supplying the liquid to the liquid ejecting means when the liquid ejecting means is opened is provided. The liquid supply valve is configured to automatically open and close periodically.
In the invention according to claim 9, the liquid ejecting means is configured to eject water. According to a tenth aspect of the present invention, in addition to the configuration of the ninth aspect, a water supply means for supplying water to the liquid injection means from a cell cooling water system attached to the fuel cell power generation facility or another water treatment facility. Have more. In the eleventh aspect of the invention, the liquid ejecting means is configured to eject a liquid having a property of dissolving the electrolyte or the electrolyte compound or fluidizing the solidified electrolyte compound.

[0025]

According to the present invention having the above construction, the electrolyte or electrolyte compound deposited / adhered to the inside of the system can be removed by improving the fuel gas circulation system or the oxidant gas circulation system. That is, claim 1
According to the described invention, by injecting the liquid into the system on the downstream side of the fuel cell main body by the liquid injecting means, it is possible to remove the electrolyte or the electrolyte compound deposited / adhered to the inside of the system. Then, after this, the liquid recovery means can recover the liquid containing the electrolyte or the electrolyte compound and discharge the electrolyte or the electrolyte compound together with the liquid to the outside of the system.

According to the second aspect of the present invention, the liquid or the electrolyte compound deposited / adhered to the inside of the pipe can be removed by injecting the liquid into the inside of the pipe on the downstream side of the fuel cell body by the liquid injection means. it can. Then, after this, the liquid recovery means can recover the liquid containing the electrolyte or the electrolyte compound and discharge the electrolyte or the electrolyte compound together with the liquid to the outside of the system.

According to the third to seventh aspects of the invention, the electrolyte flowing out from the fuel cell main body has an electrolyte deposition / adhesion region (low temperature region, strainer wire mesh, heat exchange) provided in the downstream portion of the fuel cell main body. Vessel, mesh member or fibrous member)
In the above, it will be deposited and adhered as an electrolyte or an electrolyte compound. Therefore, in this state, by injecting the liquid into the electrolyte deposition / adhesion region (low temperature region, wire mesh of the strainer, heat exchanger, mesh member or fibrous member) by the liquid injection means, the precipitated or adhered electrolyte or electrolyte compound Can be removed intensively. Then, thereafter, the liquid containing the electrolyte or the electrolyte compound can be collected by the liquid collecting means, and the electrolyte or the electrolyte compound can be easily and surely discharged to the outside of the system together with the liquid.

According to the eighth aspect of the invention, the liquid supply valve is automatically opened and closed to periodically inject the liquid by the liquid ejecting means, so that the electrolyte or the electrolyte compound deposited / adhered to the inside of the system is discharged. It can be easily and reliably removed periodically. Therefore, the influence of the electrolyte or the electrolyte compound inside the system can be kept below a certain level for a long period of time.

According to the invention described in claim 9, by injecting water by the liquid ejecting means, the water is deposited inside the system.
The attached electrolyte or electrolyte compound can be removed by washing with water. As described above, when water is used, the supply of water and the structure for that are relatively easy as compared with the case of using other liquids, and thus are excellent in practicality. Further, according to the invention described in claim 10, since the water of the battery cooling water system or other water treatment equipment can be reused by the water supply means, it is more practical. In particular, since the purity of water obtained from the water treatment facility attached to the fuel cell power generation facility is high, it is possible to prevent corrosion of the target site to be injected as much as possible. Further, since it is easy to increase the supply pressure, it is possible to inject at a high speed, and it is possible to physically and efficiently remove the electrolyte or the electrolyte compound.

According to the eleventh aspect of the present invention, by injecting the liquid by the liquid injecting means, the electrolyte or the electrolyte compound attached inside the system can be dissolved or the solidified electrolyte compound can be fluidized. Therefore, the electrolyte or electrolyte compound deposited / adhered to the inside of the system can be efficiently removed chemically.

[0031]

EXAMPLES A plurality of examples in which the present invention is applied to a phosphoric acid fuel cell power generation facility using phosphoric acid as an electrolyte will be specifically described below with reference to FIGS.

[1] First Embodiment FIG. 1 FIG. 1 is a diagram showing a first embodiment of a phosphoric acid fuel cell power generation facility to which the inventions described in claims 1, 2, 8 and 9 are applied. . In FIG. 1, reference numeral 11 is a gas pipe arranged in a portion on the downstream side of the fuel cell main body in the fuel gas circulation system or the oxidant gas circulation system. This gas pipe 11
Is composed of an inclined portion 11a on the upstream side and a vertical portion 11b on the downstream side, and the lower end portion of the inclined portion 11a and the vertical portion 11b.
Is formed in a substantially V shape by connecting the lower ends of the.

A water jet nozzle (liquid jetting means) 12 for jetting water into the inclined portion 11a is provided at a part of the inclined portion 11a of the gas pipe 11. A water supply pipe 13 provided outside the gas pipe 11 is connected to the water injection nozzle 12, and the water supply pipe 13 is provided.
A water supply valve (liquid supply valve) 14 is provided midway. In this case, water is always supplied to the water supply pipe 13. The water supply valve 14 is normally in a closed state, and is configured to automatically open periodically to supply water to the water injection nozzle 12.

On the other hand, the vertical portion 11 of the V-shaped gas pipe 11
A drain pot (liquid recovery means) 15 for temporarily storing water is provided at a lower end portion of b so as to project downward from a connection portion with the lower end portion of the inclined portion 11a. A drain discharge pipe 16 and a drain valve 17 are provided below the drain pot 15, and when the drain valve 17 is opened, water accumulated in the drain pot 15 is discharged to the drain 18. In this case, the drain valve 17
The opening / closing operation is automatically performed according to the water level of the drain pot 15.

The operation of this embodiment having the above structure is as follows. That is, the phosphoric acid that has flown in the form of vapor or droplets from the fuel cell body in the form of vapor or droplets is deposited and adhered to the inner surface of the gas pipe 11 as a highly viscous phosphoric acid aqueous solution. The precipitated / adhered phosphoric acid aqueous solution reacts with the material of the pipe (carbon steel, stainless steel, etc.) over time to form a phosphoric acid compound such as iron phosphate. Also, after the phosphoric acid compound is generated upstream, it comes flying,
This phosphoric acid compound may be deposited and adhered to the inner surface of the gas pipe 11.

On the other hand, in this embodiment, the water supply valve 14 is periodically opened automatically to supply water to the water injection nozzle 12, and the water injection nozzle 12 is used to supply the gas pipe 11 with water.
By injecting water into the inside of the pipe, the phosphoric acid or the phosphoric acid compound deposited / adhered to the inner surface of the gas pipe 11 can be removed by washing with water. That is, first, since the phosphoric acid aqueous solution deposited and adhered to the inner surface of the gas pipe 11 is well soluble in water, if water is injected before the formation of the phosphoric acid compound,
The phosphoric acid can be easily removed from the inner surface of the gas pipe 11. Even if water is sprayed after the phosphoric acid compound is generated by the reaction between phosphoric acid and the material of the pipe, the phosphoric acid compound generally becomes easily fluid by the addition of water. Most of the phosphoric acid compound deposited and attached to the inner surface of 11 can be washed away by jetting water.

The water thus used for removing the phosphoric acid flows through the inclined portion 11a of the gas pipe 11 into the drain pot 15, and is temporarily stored in the drain pot 15. When the water level of the water stored in the drain pot 15 exceeds a certain level, the drain valve 17 is automatically opened, and the water in the drain pot 15 is automatically discharged to the drain 18.

As described above, according to the present embodiment, the water injection nozzle 12 allows the gas pipe 1 on the downstream side of the fuel cell main body.
By injecting water into the inside of 1, the gas pipe 11
Since the phosphoric acid or the phosphoric acid compound deposited / attached to the inner surface of the gas pipe 11 can be removed, the inclined portion 1 of the gas pipe 11 can be removed.
It is possible to avoid the adverse effect of phosphoric acid or a phosphoric acid compound on the performance of the plant downstream of the injection target portion 1a. In particular, in the present embodiment, the water supply valve 14 is automatically opened periodically, and the water is jetted periodically by the water jet nozzle 12, so that phosphoric acid or phosphoric acid deposited or attached to the inner surface of the gas pipe 11 is discharged. The compound can be easily and reliably removed periodically.

That is, in the present embodiment, the phosphoric acid or the phosphoric acid compound can be removed not only during the operation and shutdown of the plant, but also without performing the disassembling / cleaning work of the equipment and piping. Therefore, the influence of phosphoric acid or a phosphoric acid compound in the fuel gas circulation system or the oxidant gas circulation system can be kept below a certain level for a long period of time. Therefore, it is possible to reduce the frequency of stopping the plant and improve the operation reliability. In addition, the time required for disassembling and cleaning the equipment and pipes in the past can be reduced, improving the maintainability of the plant, reducing maintenance costs, and increasing the operating rate of the plant. Can be improved.
In addition, in the present embodiment, water is used as the liquid to be jetted, and the supply of water and the structure for that are relatively easy as compared with the case of using other liquids, so that it is highly practical. There is also the advantage of being.

[2] Second Embodiment ... FIG. 2 FIG. 2 is a diagram showing a second embodiment of a phosphoric acid fuel cell power generation facility to which the inventions of claims 1 to 4, 8 and 9 are applied. . In FIG. 2, the inclined portion 11a of the gas pipe 11
And the heat insulating material 19 is arrange | positioned at the upper part of the vertical part 11b so that the circumference | surroundings of the gas pipe 11 may be covered,
In the lower part, which is the connecting part between the inclined part 11a and the vertical part 11b,
The heat insulating material 19 is not arranged. That is, the gas pipe 1
Below the inclined portion 11a and the vertical portion 11b of the No. 1, low temperature regions 20a and 20b each having a temperature lower than the temperature of the gas flowing into this region are provided.

Then, the inclined portion 11a and the vertical portion 11b
Inside the water, water injection nozzles (liquid injection means) 12a, 12b for injecting water into the low temperature regions 20a, 20b therebelow.
Is provided. These water jet nozzles 12a, 12b
Is connected to the corresponding branch portions 13a and 13b of the water supply pipe 13 provided outside the gas pipe 11, and is a common water supply valve (liquid supply valve) provided in a single pipe portion of the water supply pipe 13. ) 14 to receive water at the same time. Like the first embodiment, the water supply valve 14 is normally in a closed state, and is configured to automatically open periodically to supply water to the water injection nozzle 12. The other parts are constructed in exactly the same way as in the first embodiment.

The operation of this embodiment having the above structure is as follows. That is, the phosphoric acid that has flown from the fuel cell main body in the form of vapor or droplets in the form of vapor or droplets is formed as a highly viscous phosphoric acid aqueous solution on the inner surfaces of the low temperature regions 20a and 20b where there is no heat insulating material, or in the piping. Precipitates and adheres as a phosphoric acid compound generated by reacting with the material. Further, there is a case where the phosphoric acid compound is generated upstream and then comes flying, and the phosphoric acid compound is deposited / adhered to the inner surfaces of the low temperature regions 20a and 20b. In this embodiment, the low temperature region 20
Water injection nozzles 12a, 12
By locally injecting water with b, it is possible to intensively remove the phosphoric acid or the phosphoric acid compound deposited / adhered to the low temperature regions 20a and 20b. In addition, the water after being used for removing the phosphoric acid as described above flows through the inclined portion 11a of the gas pipe 11 into the drain pot 15 and is temporarily stored in the drain pot 15 as in the first embodiment. After that, the drain valve 17 is automatically opened and the drain 1
It is discharged to 8 as appropriate.

As described above, according to the present embodiment, by locally injecting water into the low temperature regions 20a, 20b of the gas pipe 11 by the water injection nozzles 12a, 12b, the inner surface of the low temperature regions 12a, 12b is increased. Since the phosphoric acid or the phosphoric acid compound deposited and adhered to the gas can be intensively removed, the adverse effect of the phosphoric acid or the phosphoric acid compound on the plant performance downstream of the low temperature regions 12a and 12b of the gas pipe 11 is minimized. It can be avoided. Particularly, in the present embodiment, similarly to the first embodiment, by periodically and automatically opening the water supply valve 14, the phosphoric acid or phosphorus deposited / adhered to the inner surfaces of the low temperature regions 12a, 12b of the gas pipe 11 is removed. The acid compound can be periodically and easily removed.

Therefore, as in the first embodiment, the influence of phosphoric acid or a phosphoric acid compound in the fuel gas circulation system or the oxidant gas circulation system can be kept below a certain level for a long period of time. The frequency of stopping the plant can be reduced and the operational reliability can be improved.
Furthermore, the maintainability of the plant can be improved, the maintenance cost can be reduced, and the operating rate of the plant can be improved. Further, similarly to the first embodiment,
Since water is used as the liquid to be jetted, it is highly practical.

[3] Third Embodiment FIG. 3 FIG. 3 is a view showing a third embodiment of a phosphoric acid fuel cell power generation facility to which the inventions of claims 1 to 5, 5 and 9 are applied. . In FIG. 3, the gas pipe 21 is composed of a vertical portion 21a on the upstream side and a horizontal portion 21b on the downstream side, and is substantially L-shaped by connecting the lower end portion of the vertical portion 21a and one end of the horizontal portion 21b. Is formed in. Then, the strainer 2 including a wire mesh (element) for removing moisture in the gas is provided in a part of the vertical portion 21a of the gas pipe 21.
2 are provided. Furthermore, in this gas pipe 21,
A differential pressure gauge 23 is provided for measuring and displaying the pressure difference between the upstream side and the downstream side of the strainer 22.

Further, the strainer 2 is provided at a position near the upper portion of the strainer 22 in the straight portion 21a of the gas pipe 21.
2 is provided with a water jet nozzle 12 for jetting water.
A water supply pipe 13 and a water supply valve 14 are connected to the water injection nozzle 12 as in the first embodiment. In this case, the water supply valve 14 is electrically connected to the differential pressure gauge 23,
Normally, it is in a closed state, and is configured to automatically open and supply water to the water injection nozzle 12 when the pressure difference between the upstream side and the downstream side of the strainer 22 measured by the differential pressure gauge 23 rises above a predetermined value. ing.

On the other hand, at the lower end of the vertical portion 21a of the gas pipe 21, a drain pot (liquid recovery means) 15 for temporarily storing water is provided so as to project downward from the connection portion with the horizontal portion 21b. Has been. A drain discharge pipe 16 and a drain valve 17 are connected to the drain pot 15 as in the first embodiment.

The operation of this embodiment having the above-mentioned structure is as follows. That is, the phosphoric acid that has flown in the form of vapor or droplets from the fuel cell main body in the form of vapor or droplets, or the phosphoric acid compound that has flowed after being generated in the upstream deposits and adheres to the wire mesh of the strainer 22, and Deposit on. When the phosphoric acid or the phosphoric acid compound is deposited on the wire mesh of the strainer 22 in this way, the pressure difference between the upstream side and the downstream side of the strainer 22 increases, and this pressure difference is measured and displayed by the differential pressure gauge 23.

Then, when the pressure difference between the upstream side and the downstream side of the strainer 22 measured and displayed by the differential pressure gauge 23 rises above a predetermined value, the water supply valve 14 automatically opens to supply water to the water injection nozzle 12. To do. As a result, strainer 22
By locally injecting water from the water injection nozzle 12 onto the wire mesh of the
The deposited phosphoric acid or phosphoric acid compound can be efficiently removed. The water thus used for removing the phosphoric acid flows through the vertical portion 21a of the gas pipe 21 into the drain pot 15, and after being temporarily stored in the drain pot 15, the drain valve 17 is automatically operated. When opened, the drain 18 is appropriately discharged.

As described above, according to this embodiment, by locally injecting water onto the wire mesh of the strainer 22 by the water injection nozzle 12, phosphoric acid or phosphoric acid adhered to and deposited on the wire mesh of the strainer 22. Since the compound can be removed efficiently, the adverse effect of phosphoric acid or the phosphoric acid compound on the plant performance downstream of the strainer 22 can be avoided as much as possible. In particular, in this embodiment, by automatically opening the water supply valve 14 in accordance with the pressure difference between the two sides of the strainer 22, the phosphoric acid or the phosphoric acid compound attached to the wire mesh of the strainer 22 can be easily and reliably obtained when necessary. Can be removed.

Therefore, as in the first and second embodiments,
The effects of phosphoric acid or phosphate compounds in the fuel gas circulation system or oxidant gas circulation system can be kept below a certain level for a long period of time, reducing the frequency of plant shutdowns and improving operational reliability. Can be improved. Furthermore, the maintainability of the plant can be improved, the maintenance cost can be reduced, and the operating rate of the plant can be improved. Further, as in the first and second embodiments, since water is used as the liquid to be jetted, it is excellent in practicality.

[4] Fourth Embodiment ... FIG. 4 FIG. 4 is a view showing a fourth embodiment of a phosphoric acid fuel cell power generation facility to which the invention described in claims 1 to 3, 6, 8 and 9 is applied. Is. In FIG. 4, the gas pipe 21 is composed of a vertical portion 21a on the upstream side and a horizontal portion 21b on the downstream side, and is substantially L-shaped by connecting the lower end portion of the vertical portion 21a and one end of the horizontal portion 21b. Is formed in. A heat exchanger 24 is provided at a part of the vertical portion 21a of the gas pipe 21.
Is provided. The heat exchanger 24 is a fin-tube type heat exchanger, and includes heat transfer fins 25 and heat exchange fluid passages 26.

Inside the heat exchanger 24, a plurality of water jet nozzles 12 for jetting water to the heat transfer fins 25 are provided. A water supply pipe 13 and a water supply valve 14 are connected to the water injection nozzle 12 as in the first embodiment. In this case, the water supply valve 14 is normally in a closed state and is configured to automatically open periodically to supply water to the water injection nozzle 12.

On the other hand, a drain pot (liquid recovery means) 15 for temporarily storing water is provided at the lower end of the vertical portion 21a of the gas pipe 21 so as to project downward from the connection portion with the horizontal portion 21b. Has been. A drain discharge pipe 16 and a drain valve 17 are connected to the drain pot 15 as in the first embodiment.

The operation of this embodiment having the above configuration is as follows. That is, the phosphoric acid that has flown in the form of vapor or droplets from the fuel cell main body in the form of vapor or droplets or the phosphoric acid compound that has flowed after being generated upstream is deposited on the heat transfer fins 25 of the heat exchanger 24. Adhere to.
In this case, if foreign matter adheres to and accumulates on the heat transfer fins 25 of the heat exchanger 24, the normal flow of gas is hindered, and it becomes impossible for the heat exchanger 24 to exhibit a predetermined heat exchange performance.

On the other hand, in this embodiment, the water supply valve 14 is automatically opened periodically to supply water to the water injection nozzle 12. As a result, by locally injecting water by the water injection nozzle 12 to the heat transfer fins 25,
The phosphoric acid or the phosphoric acid compound adhered / deposited on the heat transfer fins 25 can be efficiently removed. Therefore, the heat exchanger 24 can exhibit a predetermined heat exchange performance.
The water thus used for removing the phosphoric acid flows through the vertical portion 21a of the gas pipe 21 into the drain pot 15, and after being temporarily stored in the drain pot 15, the drain valve 17 is automatically operated. When opened, the drain 18 is appropriately discharged.

As described above, according to this embodiment, by locally injecting water to the heat transfer fins 25 of the heat exchanger 24 by the water injection nozzle 12, the phosphoric acid adhered to the heat transfer fins 25 is discharged. Alternatively, since the phosphoric acid compound can be efficiently removed, the heat exchange performance of the heat exchanger 24 is not deteriorated, and the phosphoric acid or the phosphoric acid compound downstream of the heat exchanger 24 does not affect the performance of the plant. It is possible to avoid adverse effects. Particularly, in this embodiment, as in the first embodiment, the heat transfer fins 25 of the heat exchanger 24 are automatically opened by periodically opening the water supply valve 14.
The phosphoric acid or the phosphoric acid compound attached to the can be periodically and easily removed.

Therefore, as in the first, second, and third embodiments, the effect of phosphoric acid or a phosphoric acid compound in the fuel gas circulation system or the oxidant gas circulation system is kept below a certain level for a long period of time. Because it is possible to keep
It is possible to reduce the frequency of stopping the plant and improve the operation reliability. Furthermore, the maintainability of the plant can be improved, the maintenance cost can be reduced, and the operating rate of the plant can be improved. Also,
Similar to the first, second, and third embodiments, since water is used as the liquid to be jetted, it is excellent in practicality.

[5] Other Embodiments The present invention is not limited to the above-described embodiments, and various other modified examples can be implemented. For example, by applying the invention of claim 7, instead of the strainer 22 of the third embodiment, a mesh member or a fibrous member made of a material such as stainless steel which is not easily corroded by phosphoric acid is inserted, and this portion is inserted in this portion. It can also be configured to spray water. Also in this case, the phosphoric acid that has flowed in from the fuel cell body in the form of vapor or droplets in the form of gas or the phosphoric acid compound that has flowed in after being generated in the upstream,
After intentionally adhering to the mesh member or the fibrous member, it can be efficiently removed.

Further, after grasping the deposition / adhesion amount of phosphoric acid or a phosphoric acid compound over time in advance, such deposition / adhesion
It is also possible to configure the water supply valve 14 to be automatically opened and closed every necessary period according to the amount of adhesion. In this case,
It is possible to automatically remove foreign matter from the target site or target device during unmanned operation, and to maintain a normal operating condition for a long period of time.

Further, by applying the invention according to claim 10, by providing a pipe for supplying water from the cell cooling water system attached to the fuel cell power generation facility or another water treatment facility to the water injection nozzle, It is possible to effectively reuse the water of the water treatment equipment of. When water from such a water treatment facility is used, the purity of the obtained water is high, so that corrosion of the target site to be sprayed can be prevented as much as possible. Further, since it is easy to increase the supply pressure, it is possible to inject at a high speed, and it is possible to physically and efficiently remove phosphoric acid or a phosphoric acid compound.

On the other hand, in the above description, the structure for injecting water from the water injection nozzle has been described.
By applying the described invention and using, instead of water, a liquid having the property of dissolving phosphoric acid or a phosphoric acid compound or fluidizing a solidified phosphoric acid compound,
It is possible to chemically and efficiently remove phosphoric acid or a phosphoric acid compound attached to the inside of the fuel gas circulation system or the oxidant gas circulation system.

Further, the present invention can be similarly applied to a fuel cell power generation facility using an electrolyte other than phosphoric acid, and can similarly obtain excellent actions and effects.

[0064]

As described above, according to the present invention,
The electrolyte or electrolyte compound that adheres to the inside of the fuel cell power generation facility is not limited to when the plant is in operation or stopped, and
Since it can be removed without disassembling and cleaning the equipment, piping, etc., it is possible to avoid the adverse effect of the electrolyte or electrolyte compound on the performance of the plant as much as possible, reducing the frequency and time to stop the plant, A fuel cell power generation facility with high plant operation reliability, maintainability, and availability can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a phosphoric acid fuel cell power generation facility according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a phosphoric acid fuel cell power generation facility according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a phosphoric acid fuel cell power generation facility according to a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a phosphoric acid fuel cell power generation facility according to a fourth embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing an example of conventional phosphoric acid fuel cell power generation equipment.

[Explanation of symbols]

 11, 21 ... Gas pipe 12 ... Water injection nozzle (liquid injection means) 13 ... Water supply pipe 14 ... Water supply valve (liquid supply valve) 15 ... Drain pot (liquid recovery means) 16 ... Drain discharge pipe 17 ... Drain valve 18 ... Drain 19 ... Heat insulating material 20a, 20b ... Low temperature area 22 ... Strainer 23 ... Differential pressure gauge 24 ... Heat exchanger 25 ... Heat transfer fin 26 ... Flow path

Claims (11)

[Claims] 1. A fuel cell body comprising a fuel electrode and an oxidant electrode, a fuel gas circulation system and an oxidant gas for circulating a fuel gas and an oxidant gas to the fuel electrode and the oxidant electrode of the fuel cell body, respectively. In a fuel cell power generation facility that includes a circulation system and generates electricity by an electrochemical reaction between the fuel electrode and the oxidant electrode, a portion of the fuel gas circulation system or the oxidant gas circulation system on a downstream side of the fuel cell main body. A fuel cell power generation facility comprising: a liquid ejecting unit that ejects a liquid into the system, and a liquid collecting unit that collects the liquid ejected by the liquid ejecting unit and discharges the liquid to the outside of the system. 2. The liquid injection means and the liquid recovery means are provided inside a pipe on the downstream side of the fuel cell main body of the fuel gas circulation system or the oxidant gas circulation system. 1. The fuel cell power generation facility according to 1. 3. An electrolyte attachment / precipitation region for intensively depositing or depositing an electrolyte or an electrolyte compound of the fuel cell body on a portion of the fuel gas circulation system or the oxidant gas circulation system on the downstream side of the fuel cell body. 2. The fuel cell power generation facility according to claim 1, wherein the liquid injection unit is configured to inject a liquid into the electrolyte deposition / adhesion region. 4. The fuel cell according to claim 3, wherein the electrolyte deposition / adhesion region is configured as a low temperature region having a temperature lower than the temperature of the fuel gas or the oxidant gas flowing into this region. Power generation equipment. 5. The fuel cell power generation facility according to claim 3, wherein a strainer having a wire mesh is inserted in the electrolyte deposition / adhesion region. 6. The fuel cell power generation facility according to claim 3, wherein the electrolyte deposition / adhesion region is formed inside a heat exchanger. 7. The fuel cell power generation facility according to claim 3, wherein a mesh member or a fibrous member made of a material having corrosion resistance to an electrolyte is inserted in the electrolyte deposition / adhesion region. 8. A liquid supply valve is provided to supply liquid to the liquid ejecting means when the liquid ejecting means is opened.
The fuel cell power generation facility according to claim 1, wherein the fuel cell power generation facility is configured to automatically open and close periodically. 9. The fuel cell power generation equipment according to claim 1, wherein the liquid injection means is configured to inject water. 10. The fuel cell according to claim 9, further comprising water supply means for supplying water to the liquid injection means from a cell cooling water system attached to the fuel cell power generation equipment or another water treatment equipment. Power generation equipment. 11. The liquid ejecting means is configured to eject a liquid having a property of dissolving an electrolyte or an electrolyte compound or fluidizing a solidified electrolyte compound. Fuel cell power generation equipment.