JPH08185883A - Fuel cell power generation facility - Google Patents

Abstract

PURPOSE: To obtain a fuel cell power generation facility having simple constitution, occupying less space, and further having the capability of continuously discharging water from a drain during an operation, and eliminating the adverse effect of condensed water on a transformer, a fuel cell, a reformer or the like. CONSTITUTION: Regarding the gas flow passage of a fuel cell, a gas line 27 for exhaust gases having the lowest gas pressure is fitted with the first drain pipeline 41, and a gas flow passage upstream thereof is provided with the second drain pipelines 42 to 44. In this case, the pipelines 42 to 44 have a smaller diameter than the the gas flow passage thereof, and outflowing gases are released to the first drain pipeline 41, together with drain from the second drain pipeline 43. Also, the outlet of the first drain pipeline 41 is water sealed with a drain tank 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a series of gas paths for supplying fuel gas containing water vapor to a fuel cell and discharging exhaust gas containing water vapor generated by the electrochemical reaction in the gas path. The present invention relates to a fuel cell power generation facility in which condensed water that has been discharged is drained to eliminate adverse effects of condensed water on fuel cells and the like.

[0002]

2. Description of the Related Art Fuel cell power generation equipment has high power generation efficiency and is attracting attention as an on-site type commercial fuel cell. For example, a 200 kW phosphoric acid fuel cell power generation facility is housed in a package measuring about 3 m (length) x 6 m (width) x 3 m (height),
Some of the building's distributed power sources were commissioned, and in such a limited space, sufficient space was secured to drain the condensed water (drain) generated by the condensation of steam in this equipment. It's getting harder to do.

FIG. 8 is a system diagram showing a gas and drain system of a conventional fuel cell power generation facility used for the above test operation. In the figure, 1 is a reformer of the fuel cell, which is produced from city gas and steam. Gas pipeline for supplying the hydrogen gas as a fuel gas together with water vapor to the CO transformer,
2 is CO that converts carbon monoxide CO and steam remaining in the fuel gas into hydrogen and carbon dioxide by a catalytic reaction.
The transformer 3, a gas pipeline for sending the transformed fuel gas to the fuel cell, 4 is inside the body of the fuel cell, and a fuel electrode for generating electricity from the fuel gas by an electrochemical reaction with the air electrode, Reference numeral 5 is an inlet manifold of the fuel electrode 5, 6 is an outlet manifold of the fuel electrode 4, and 7 is an unreacted fuel gas discharged from the fuel electrode 4 through the outlet manifold 6 and a reacted gas containing water vapor as exhaust gas. It is a gas pipe line that sends the gas to the reformer combustion section for discharge and combustion treatment.

Further, 8 is a drain pipe for draining the drain which has become condensed water from the steam inside the gas pipe line 1, and 9 is a drain trap for draining the drain by reducing gas leakage from the drain pipe 8. Reference numeral 10 is a shutoff valve for shutting off the drain and gas flowing out from the drain trap 9, similarly, 11 is a drain pipe provided in the gas pipeline 3, 12 is a drain trap of the drain pipe 11,
13 is a cutoff valve provided corresponding to the drain and the wrap 12, 14 is a drain pipe provided in the outlet manifold 6 of the fuel electrode 4, and 15 is a drain pipe which stores the drain.
A drain tank for water-sealing the gas flowing out from the outlet of the drain pipe 14, 16 is an overflow pipe for draining surplus water so as to keep the water level of the drain tank constant, and similarly, 1
7 is a drain pipe provided in the gas pipe 7, 18 is a drain tank thereof, and 19 is an overflow pipe thereof.

Next, the operation will be described. The fuel gas and the exhaust gas after the electrochemical reaction are processed by continuously flowing through a series of gas paths including the reformer, the CO shift converter 2, the fuel electrode 4, and the reformer combustion section, and are processed upstream. Flowing due to the difference between the pressure on the side and the pressure on the downstream side. In addition, this gas contains a large amount of water vapor component, and immediately after the fuel cell power generation facility is started, especially when the temperature of the gas pipe line is low, this water vapor component is cooled in the pipe line and condensed water is condensed. When this water enters the CO shift converter 2 and the fuel electrode 4, etc., it damages the catalyst and dilutes the electrolyte, degrading the performance and life of these devices. If it enters, there is a risk of burner misfire, so it is necessary to drain this condensed water out of the system as soon as possible. Further, even during steady operation, this water vapor may condense in a pipeline or the like, and it is desirable that the water can be continuously drained.

The drain pipe is for draining such condensed water as drain, and has a low gas pressure (about 1.
The drain pipes 14 and 18 provided in the outlet manifold 6 and the gas pipe line 7 are provided with water tanks of the drain tanks 15 and 18, and the pipe outlet is arranged near the bottom of the drain tank. As a result, the gas outflow from this outlet is sealed by water pressure, and only the drain is drained. An overflow pipe is provided in each of the drain tanks 15 and 18, and the excess water is drained so that the water level in the tank is kept constant. The height of the water seal in this case is about 30 cm to 50 cm in terms of water level, and the drain tank is not so large.

On the other hand, the gas pressure is high (about 1.07 to
Since the drain pipes 8 and 11 provided in the gas pipelines 1 and 3 are water-sealed with a drain tank, the water-sealing height of the water tank is about 70 cm to 100 cm.
Drain traps 9 and 12 and shut-off valve 10 respectively
And 13 are provided, and the drain traps 9 and 12 are configured so that the drain is not discharged unless the drain is accumulated so as to reduce the outflow of gas. However, when drainage is accumulated, fuel gas flows out from the drain traps 9 and 12 at the same time as drainage is drained. Therefore, the shutoff valves 10 and 13 should be opened immediately after the fuel cell power generation facility is started and only when drainage is likely to occur. The shutoff valves are closed when the temperature of the gas pipeline increases to a temperature at which condensation does not easily occur.

[0008]

Since the conventional fuel cell power generation equipment is configured as described above, immediately after the fuel cell power generation equipment is started, the fuel gas, which is a combustible gas, is shut off together with the drain. It was dangerous to leak from. Further, during the subsequent steady operation, since the shutoff valve is closed and the operation is continued, even if a small amount of condensed water is generated in the gas pipeline, CO
There is a problem that these devices are adversely affected because they enter the transformer and the fuel electrode. Further, if a drain trap or a shutoff valve is provided, the device itself becomes complicated, and a device for control is required.

In order to prevent the drain from flowing backward, a pipe or a device for taking out the drain must be provided at the bottom of the fuel cell power generation equipment, and the installation space is limited in the miniaturized and packaged fuel cell power generation equipment. Therefore, it is very difficult to provide a large drain tank or increase the number of drain tanks.

The present invention has been made in order to solve the above-mentioned problems, and has a simple structure and saves space.
It is an object of the present invention to obtain a fuel cell power generation facility that can continuously drain drainage even during operation, and can eliminate the adverse effects of condensed water on a transformer, fuel cell, reformer, etc.

[0011]

A fuel cell power generation facility according to claim 1 of the present invention is provided in a gas passage, and induces and drains condensed water generated in a gas passage in the vicinity thereof.
Drain pipe of the above, at one or more positions upstream of the position where this first drain pipe is provided, provided in the above-mentioned gas path, and guiding and discharging the condensed water generated in the gas path around each of them. A second drain pipe that discharges a part of the gas in the gas passage together and has a portion having a cross-sectional area smaller than the cross-sectional area of the gas passage at the position where the gas is provided,
And a drain tank having an overflow portion for water-sealing the gas flowing out from the first drain pipe and the second drain pipe to the outside air, and for draining surplus water so as to keep the water level constant, the first drain A connecting portion is provided for connecting the gas discharged from the pipe and the second drain pipe and the condensed water so as to collect the condensed water.

A fuel cell power generation facility according to a second aspect of the present invention is provided in a gas passage, and a first drain pipe for guiding and discharging condensed water generated in a gas passage in the vicinity thereof, the first drain pipe. A drain tank provided at the outlet of the drain pipe to store the condensed water and to seal the gas outflow from the first drain pipe outlet by water pressure according to the height from the outlet to the water surface, A drain tank device having an overflow part for draining surplus water so as to keep the water level of the tank constant, and one or more positions upstream of the position where the first drain pipe is provided, to the gas path. Condensate generated in the gas passages around each of the gas passages is guided and drained, and part of the gas in the gas passages is discharged together. Has a portion of even smaller cross-sectional area, the outlet is one with a second drain pipe connected to the first drain pipe.

In the fuel cell power generation facility according to claim 3 of the present invention, the first drain pipe is provided in the gas path downstream of the fuel cell.

In the fuel cell power generation equipment according to claim 4 of the present invention, the first drain pipe is provided in the gas pipe passage for discharging the exhaust gas emitted from the fuel cell, and the second drain pipe is provided in the outlet manifold of the fuel cell. It is provided.

In the fuel cell power generation facility according to claim 5 of the present invention, the first drain pipe is provided in the gas pipe line for supplying the fuel gas from the transformer to the fuel cell, and the second drain pipe is provided in the transformer. It is provided in a gas pipeline for supplying gas.

In the fuel cell power generation facility according to claim 6 of the present invention, a first drain pipe is provided in a gas pipe passage for discharging exhaust gas discharged from the fuel cell, and a second drain pipe is provided in the transformer for fuel gas. For supplying the fuel gas to the fuel cell from the transformer, and the outlet manifold of the fuel cell.

In the fuel cell power generation facility according to claim 7 of the present invention, since the condensed water generated in the gas path is guided and drained, the portion provided in the gas path and having a sectional area smaller than that of the gas path is provided. A drain pipe having, and provided at the outlet of the drain pipe to store the condensed water, and against the pressure of the drain pipe outlet, by the water pressure corresponding to the height from the outlet to the water surface, the outlet A drain tank for suppressing the outflow of gas from the outlet, a vent pipe for discharging the gas flowing out from the outlet to the outside air, and a drain having an overflow portion for draining surplus water so as to keep the water level of this tank constant. It is equipped with a tank device.

The fuel cell power generation facility according to claim 8 of the present invention is provided in the gas passage for guiding and discharging the condensed water generated in the gas passage, and has a U-shape below the gas passage. It is provided with a drain pipe having a curved portion.

[0019]

In the fuel cell power generation facility according to claim 1 of the present invention, the first drain pipe provided in the gas path guides and drains condensed water generated in the gas path around the first drain piping. A second drain pipe, which is provided in the gas passage at one or more positions upstream of the position where the drain pipe is provided, and has a portion having a cross-sectional area smaller than the cross-sectional area of the gas passage at the provided position, Condensed water generated in the gas passages around each of them is guided and drained, and a part of the gas in the gas passages is decompressed and released together by the pipe loss due to the area difference of the pipes. The discharged gas is decompressed to the pressure of the gas path which is the outlet of the first drain pipe, and the drain tank having an overflow portion for draining surplus water to keep the water level constant is The gas flowing from the second drain pipe to the outside air is water-sealed according to the reduced gas pressure, and the connecting portion is condensed with the gas released from the first drain pipe and the second drain pipe. Connect to collect water,
The condensed water is drained to the drain tank, and the gas released from the second drain pipe is returned to the gas path via the first drain pipe.

In the fuel cell power generation facility according to the second aspect of the present invention, the first drain pipe provided in the gas path guides and drains condensed water generated in the gas path around the first drain piping, and the first drain piping is provided. The drain tank of the drain tank device provided at the outlet of the drain pipe stores the condensed water, and at the same time, the gas outflow from the outlet of the first drain pipe is watered by the water pressure corresponding to the height from the outlet to the water surface. The excess water is sealed so that the overflow portion of the drain tank device keeps the water level of the tank constant, and the gas is discharged at one or more positions upstream of the position where the first drain pipe is provided. A second passage that is provided in the passage and has a portion having a cross-sectional area smaller than the cross-sectional area of the gas passage at the position where the second passage is connected to the first drain pipe;
The drain pipes of the above guide the condensed water generated in the gas passages around each of them to drain the condensed water, and reduce a part of the gas in the gas passages together by decompressing it by the pipe loss due to the area difference of the pipes. The condensed water is discharged to the drain tank, and the gas discharged from the second drain pipe is
The pressure is reduced to the pressure of the gas passage which is the outlet of the first drain pipe, and returned to the gas passage via the first drain pipe.

In the fuel cell power generation facility according to claim 3 of the present invention, the first drain pipe is provided downstream of the fuel cell in the gas path having a low pressure, and the first drain pipe and the second drain pipe are connected. The gas flowing to the outside air is water-sealed according to the low pressure in the gas passage downstream of the fuel cell.

In the fuel cell power generation facility according to claim 4 of the present invention, the first drain pipe is provided in a gas pipe passage for discharging exhaust gas emitted from the fuel cell, and the second drain pipe is provided at the outlet of the fuel cell. The second is provided on the manifold.
Exhaust gas discharged from the drain pipe is returned to the gas pipe path for discharging the exhaust gas emitted from the fuel cell, which is the gas path of the same exhaust gas, via the first drain pipe.

In the fuel cell power generation facility according to claim 5 of the present invention, the first drain pipe is provided in a gas pipe line for supplying the fuel gas from the transformer to the fuel cell, and the second drain pipe is provided in the transformer. The fuel gas that is provided in the gas pipeline that supplies the fuel gas to the
The same fuel gas is returned from the transformer to the gas pipe line for supplying the fuel cell to the fuel cell via the first drain pipe.

In the fuel cell power generation facility according to claim 6 of the present invention, the first drain pipe is provided in a gas pipe passage for discharging exhaust gas emitted from the fuel cell, and the second drain pipe is connected to the fuel converter. A gas line for supplying gas, a gas line for supplying fuel gas from the transformer to the fuel cell, and a manifold at the outlet of the fuel cell, which are respectively provided in the first drain pipe and the second drain pipe. Condensed water generated in a series of gas paths is collectively discharged by.

In the fuel cell power generation facility according to claim 7 of the present invention, a drain pipe provided in the gas path and having a portion having a cross-sectional area smaller than the gas path guides condensed water generated in the gas path to drain the water. In addition, the outflow gas from the gas passage is decompressed and discharged by the pipeline loss due to the area difference of the pipeline, and the drain tank of the drain tank device provided at the outlet of the drain piping stores the condensed water, Against the pressure of the drain pipe outlet, by a water pressure according to the height from this outlet to the water surface, suppress the gas outflow from the outlet, the vent pipe of the drain tank device,
The gas flowing out from the outlet is discharged to the outside air, and the overflow part of the drain tank device drains the excess water so that the water level of this tank is kept constant.

In the fuel cell power generation facility according to claim 8 of the present invention, a drain pipe provided in the gas path and having a U-shaped curved portion below the gas path collects condensed water generated in the gas path. The gas outflow from the drain pipe is water-sealed by the water pressure according to the height from the lowermost part of the drain pipe to the drain outlet of the drain drained through the drain pipe.

[0027]

【Example】

Example 1. The first embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 21 to 27, 38 and 39
Are the conventional examples shown in FIGS.
9 corresponds to 9, and 21 is a gas pipe line for supplying hydrogen gas produced from city gas and steam in a reformer of a fuel cell together with steam as a fuel gas to a CO shift converter, and 22 is a fuel gas Carbon monoxide remaining in the CO
A CO converter for converting hydrogen and water vapor into hydrogen and carbon dioxide by a catalytic reaction, 23 is a gas pipe line for sending the converted fuel gas to the fuel cell, and 24 is in the main body of the fuel cell.
A fuel electrode that generates electricity from the fuel gas by an electrochemical reaction with the air electrode, 25 is an inlet manifold of the fuel electrode 24, 26 is an outlet manifold of the fuel electrode 24, 27
Is a gas pipeline for sending out a reacted gas containing unreacted fuel gas and water vapor, which is discharged from the fuel electrode 24 through the outlet manifold 26, as exhaust gas and sending it to the reformer combustion section for combustion treatment. .

Further, 41 is a first drain pipe for draining condensed water condensed in the gas pipe passage 27 of the exhaust gas exhausted from the fuel electrode 24, and 42, 43 and 44 are drain outlets of the drain pipe 41, respectively. A second drain pipe 38 having respective drain outlets in the gas pipe passages 21 and 22 and the outlet manifold 26 of the fuel electrode 24, which are upstream positions, of the drain pipes 41, 42, 43 and 44, were drained. A drain tank that stores the drain and seals the gas flowing out from the outlet of the drain pipe with water.
Reference numeral 9 is an overflow pipe for draining surplus water so as to keep the water level in the drain tank 38 constant.

Next, the operation will be described. Fuel cells
City gas and steam are converted to hydrogen gas through a reformer,
Further, due to the catalytic action of the CO shift converter 22, carbon monoxide contained in this gas is reacted with water vapor to generate hydrogen, and the fuel gas that has undergone these steps is used as the fuel electrode 2 of the fuel cell.
4, an electrochemical reaction is made between the fuel electrode 24 and the air electrode inside the fuel cell via an electrolyte (for example, phosphoric acid) to generate direct current electricity. In addition, the exhaust gas after the electrochemical reaction contains unburned gas and water vapor generated by the electrochemical reaction, and these gases are further sent to the combustion section of the reformer for combustion and reforming. It is designed to keep the temperature of the vessel high.

As described above, the gas discharged from the reformer includes the gas pipe line 21, the CO shifter 22, the gas pipe line 23, the inlet manifold 25 of the fuel electrode 24, the fuel electrode 24, and the fuel electrode 2.
A series of gas paths are configured so as to return to the reformer combustion section through the outlet manifold 26 of No. 4 and the gas pipe 27, and the gas flows through this path due to the difference between the upstream pressure and the downstream pressure. Is flowing continuously. The pressure of this gas is about 1.10 atm in the gas pipeline 21 before entering the CO shifter 22 in a normal pressure type fuel cell power generation facility,
About 1.07 atm in the gas pipe line 23 from the transformer 22 to the fuel electrode 24, and about 1.7 at the outlet manifold of the fuel electrode 24.
The pressure is 05 atm and the pressure is about 1.03 atm in the gas pipe line 27 extending from the fuel electrode 24 to the combustor of the reformer.

Further, as described in the description of the prior art,
A large amount of water vapor component is contained in this gas, and this water vapor component is cooled in the water pipe to become condensed water, especially when the temperature of the gas pipe is low immediately after the start of the fuel cell power generation facility. . When this water enters the CO shift converter 22 and the fuel electrode 24, it damages the catalyst and dilutes the electrolyte, degrading the performance and life of these devices, and this water enters the reformer combustion section. Therefore, it is necessary to drain this condensed water out of the system as soon as possible because there is a risk of burner misfire. Further, even during steady operation, this water vapor may condense in a gas pipeline or the like, and it is desirable that the water can be continuously drained.

When the condensed water generated in the gas passage is drained from these gas passages through the drain pipe, it is necessary to take out only the condensed water without taking out the gas in the gas passage, and therefore the outlet of the drain pipe is used. A drain tank is provided in the tank, and the outflow of gas is water-sealed by the water pressure in the drain tank. Therefore, if a drain tank is provided for each drain pipe, the gas pipe line 21 before entering the CO shifter 22 is about 100 cm, CO
Approximately 7 in the gas pipe line 23 from the transformer 22 to the fuel electrode 24
0 cm, about 50 cm at the outlet manifold of the fuel electrode 24,
About 30 cm is required for the gas pipe line 27 from the fuel electrode 24 to the reformer combustion section, and a drain tank having a water tank having a height equal to or higher than the water level is required.

In the first embodiment of the present invention, a drain tank 38 for sealing the outlet of the first drain pipe 41 with water is provided in the gas pipe passage 27 where the gas pressure is the minimum, and the other upstream side. The second drain pipes 42, 43, and 44 connected to the gas passage of No. 2 are connected to the first drain pipe 41 by connection, and the second drain pipe 42 provided in the gas passage of high pressure is connected. , 43 and 44 need not be provided with a drain tank.

FIG. 2 is a diagram showing a cross-section of the main part of the conduit, in which the same reference numerals indicate the same parts as in FIG.
Taking the second drain pipe 42 as an example in this figure, the difference between the pressure (1.1 atm) in the gas pipe line 21 and the pressure (1.03 atm) in the gas pipe line 27 is 0.07 atm. Due to this pressure difference, the gas is discharged from the gas pipe line 21 together with the condensed water to the first drain pipe 41 through the pipe 42. The diameter of the second drain pipe 42 is set to, for example, 6 mm, and is sufficiently smaller than the diameter of the gas pipe passage 21 of 65 mm, so that the amount of gas leaked to the first drain pipe 41 through the second drain pipe 42 is reduced. The amount can be suppressed to about 1% of the entire amount, which does not affect the power generation efficiency and characteristics of the fuel cell power generation facility.

Further, with respect to the second drain pipe 42,
By increasing the diameter of the first drain pipe 41 to, for example, 40 mm, the drain pipes 41, 42, 43 and 4 can be formed.
The drain 45 discharged by 4 drops to the drain tank by gravity, and the outflow gas 46 discharged from the outlet of the second drain pipe 42 passes through the drain pipe 41 and returns to the gas pipe passage 27. You can The other second drain pipes 43 and 44 can be configured similarly to 42.

The outflow gas 46 discharged through the pipes of the second drain pipes 42, 43 and 44 and passing through the first drain pipe 41 to the gas pipe line 27 is the second gas.
The first drain pipe from the connecting portion of the outlets of the second drain pipes 42, 43, and 44 to the gas pipe passage 27 is thickened by reducing the pressure due to the line loss in the drain pipe of the first drain pipe. It is possible to prevent almost no pressure reduction when passing through the pipe 41. Therefore, the pressure for water-sealing the outlet of the first drain pipe 41 is almost the same as the gas pressure in the gas pipe passage 27, and the water-sealing height h1 in FIG. 2 can be set to about 30 cm. In addition, h2 in FIG.
Is the first drain pipe 41 from the water surface of the drain tank 38.
It is the water level up to the outlet, and when the pressure in the first drain pipe 41 rises due to some factor and becomes equal to or higher than the water pressure of h2, it is possible to set the safety valve to discharge the internal gas.

As described above, according to the first embodiment, since the drain tank 38 is configured to take out only the drain drained from the drain pipe and to seal the outflow of gas with water, the drain is continuously drained. There is an effect that can be done. Further, the first drain pipe 41 is provided at the most downstream side of the series of gas passages, and the drain generated upstream is second drain pipes 42, 43 sufficiently thinner than the pipe diameter of each gas passage.
And 44, and the outlet is connected to the first drain pipe 41, so that the drain tanks can be combined into one, and the height of water sealing by the drain tank 38 can be minimized. There is an effect that can be.

In the first embodiment described above, the diameter of the entire second drain pipe is set to be smaller than that of the gas passage at the outlet of this pipe. The same effect can be obtained even if the cross-sectional area is smaller than the path. For example, by providing a control valve in the middle of the second drain pipe and adjusting the opening area thereof, the amount of gas flowing out via this control valve can be controlled.

Further, FIG. 3 is a view showing a structural cross section of a pipe for explaining a modified example of the first embodiment, in place of the second drain pipes 42, 43 and 44 shown in FIGS. 1 and 2. , Second drain pipes 42a, 43 with shorter pipes
a and 44a are used, and the pipe line of the connecting portion 47 is provided at the outlet of these pipes, and the second drain pipes 42
The outflow gas 46 and the drain 45 discharged from the outlets of a, 43a, and 44a are fed to the first via the connecting portion 47.
It is designed to be discharged to the drain pipe 41a.
In addition, the outlet of the first drain pipe 41a is connected to the drain tank 3
The drain provided in the upper part of 8a and stored in the water tank of the drain tank 38a can be drained to the outside by the overflow pipe 39a, and the gas inside the drain pipe is located in the drain port of the overflow pipe 39a and the drain tank 38a.
The water is sealed according to the height h1 of the water surface of a. The fuel cell power generation facility configured as described above can also obtain the same effect as that of the first embodiment.

Example 2. FIG. 4 is a system diagram showing a gas and drain system of a fuel cell power generation facility according to a second embodiment of the present invention, which is different from the system diagram of FIG. 1 showing the first embodiment.
Drain tanks 53 and 38 are provided on the upstream side and the downstream side of the fuel electrode 24, and the first drain pipes 51 and 41b and the second drain pipes 52 and 4 are provided respectively.
4b is provided. Further, 54 is an overflow pipe for draining the excess water from the drain tank 53 and keeping the water level of this tank constant, and other symbols are used in the first embodiment.
The same as the symbol of. Hereinafter, the same reference numeral indicates the same or equivalent.

The operating principle of drainage according to the second embodiment is as follows.
The operation principle is the same as that described in the first embodiment. However, the first drain pipe 51 is connected to the gas pipeline 23 for supplying the fuel gas from the CO shift converter 22 to the fuel cell, and the second drain pipe 52 is the gas pipeline for supplying the fuel gas to the CO shift converter 22. 21 and the second drain pipe 52
The fuel gas, which flows from the fuel cell to the gas pipeline 23 through the first drain pipe 51, is configured to bypass the CO shift converter 22. In the fuel gas that has passed through the CO shift converter 22, the CO gas concentration in the gas components is decreasing and the hydrogen gas concentration is increasing, but the composition of the main component does not change so much.
Even if the amount of bypass due to this outflow gas increases to some extent, it has little effect on the entire fuel cell power generation facility. Therefore, the pipe diameter of the second drain pipe 52 can be increased to some extent, and the efficiency of drain water drained through this pipe 52 can be improved. Similarly, the fuel electrode 24
Exhaust gas and gas pipeline 27 at outlet manifold 26 of
Since the exhaust gas has the same gas component, it is also possible to increase the drainage efficiency by increasing the diameter of the second drain pipe 44b.

As described above, according to the second embodiment, the second
Gas pipelines 52 and 44b to the first gas pipeline 5
Since the influence of the outflow gas returning to the gas pipelines 23 and 27 via 1 and 41b on the entire fuel cell power generation facility is reduced, the second drain pipe is provided in addition to the effect described in the first embodiment. There is an effect that the drainage efficiency can be increased by increasing the diameter of the pipeline.

Example 3. FIG. 5 is a system diagram showing a gas and drain system of a fuel cell power generation facility according to a third embodiment of the present invention. Instead of the reference numerals 8 to 13 in FIG. 8 showing a conventional example,
61 to 67 are added. In the figure, 61 is a drain pipe provided in the gas pipeline 21 for supplying the fuel gas to the CO shifter 22, 62 is a drain tank, 63 is a vent pipe for discharging the outflow gas from the drain tank 62 to the outside, and 64 is An overflow pipe provided in the drain tank 62, 65 is a drain pipe provided in the gas pipeline 23, 66 is a drain tank for sealing the outlet with water, and 67 is the overflow pipe.

In the third embodiment of the present invention, the outlet of the drain pipe 61 is not completely water-sealed, but a part of the outflow gas is discharged together with the drain so that the gas is discharged to the outside air. It is composed. At the outlet of the drain pipe 61, the amount of outflow of gas is suppressed by the water pressure of the drain tank. Further, by making the diameter of the drain pipe 61 thin, the amount of outflow gas affects the performance of the entire fuel cell power generation facility. Can be narrowed down to a level that does not give (about 1% or less). Further, since this water pressure can be made smaller than the water sealing pressure, the water tank portion of the drain tank can be made shallow. For example, in the gas pipeline 21 that supplies the fuel gas to the CO shifter 22, the gas pressure becomes about 1.1 atm and the water sealing water level is about 1 atm.
m is required, but with the above configuration, 50 cm
If the depth of the drain tank 62 is about 6
The pressure difference between the inlet and outlet of the gas flowing out via 1 is 0.
The pressure is set to 05 atmospheric pressure, and the drain pipe 61 may be throttled so that the amount of the gas flowing out due to this pressure difference becomes an appropriate amount.

The vent pipe 63 is designed to be exhausted to the outside in order to prevent the outflow gas from coming out of the drain tank 62 and catching fire. In addition, the overflow pipe 64 is configured so as not to leak the outflow gas and to withdraw only the excess water from the lower portion of the drain tank 62.

As described above, according to the third embodiment, since the diameter of the drain pipe 61 can be reduced and the depth of the water tank of the drain tank 62 can be reduced, the drain water can be continuously discharged. At the same time, there is an effect that the drain tank device can be made small.

Example 4. FIG. 6 is a system diagram showing a gas and drain system of a fuel cell power generation facility showing a fourth embodiment of the present invention. A gas for supplying a fuel gas to a CO shifter 22 in contrast to FIG. 1 showing the first embodiment. A drain pipe 71, a drain tank 72 and an overflow pipe 73 thereof are provided in place of the second drain pipe provided for the pipe line 21.

In the fourth embodiment of the present invention, the drain pipe 71 provided in the gas pipe passage 21 is provided below the gas pipe passage 21 by U
The drain tank 72 is bent in a letter shape, and a drain tank 72 is provided at the outlet at the end of the bend. The drain is continuously drained through the drain pipe 71, and the drain is stored in the drain tank 72. Drain pipe 7
Water sealing is performed by the water level difference between the water level in 1 and the water level in the drain tank 72.

The water levels of the drain pipe 71 and the drain tank 72, which are bent in a U-shape, are the same if no external pressure acts, but the drain pipe 71 depends on the gas pressure in the gas pipe passage 21. The water level inside is pushed downward and balanced by the water pressure due to the water level difference between this water level and the water level in the drain tank 72. Further, the overflow pipe 73 drains the excess water and keeps the water level in the drain tank 72 constant.

For example, in the gas pipe line 21 for supplying the fuel gas to the CO shift converter 22, the gas pressure becomes about 1.1 atm and the water sealing water level needs to be about 1 m. For example, even if the drain tank 72 has a depth of about 10 cm, the outflow gas can be water-sealed if the drain pipe 71 is arranged 90 cm or more below the drain pipe 71.

As described above, according to the fourth embodiment, even if the depth of the water tank of the drain tank 72 is shallow, the drain pipe 71 provided in the lower portion of the water tank 72 has a U shape so that the water sealing height can be increased. Since it is possible to earn money, the drain can be continuously drained, and the size of the drain tank 72 can be reduced, which has the effect of saving space. Also, FIG.
Alternatively, the drain tank may not be provided and only the drain pipe 81 may be provided, and the same effect can be obtained without the drain tank.

[0052]

Since the present invention is constructed as described above, it has the following effects.

According to the fuel cell power generation facility according to the first aspect of the present invention, the condensed water generated in the gas passage is provided with at least one first drain pipe and one or more upstream of the first drain pipe. Drain with the second drain pipe of the
The outlet pipe is squeezed to reduce the outflow gas, and the connecting portion collects the gas and condensed water flowing out from these drain pipes, drains the condensed water to a drain tank, and the water pressure of this water causes the outflow of gas to Since it was sealed, the first and second
Condensate generated in the gas passages around each of the drain pipes can be continuously drained to a common drain tank. There is an effect that the pressure can be suppressed to a value corresponding to the gas pressure in the gas path at the position where the first drain pipe having the lowest pressure at the position is provided.

According to the fuel cell power generation facility of the second aspect of the present invention, the condensed water generated in the gas passage is provided with at least one drain pipe and at least one upstream of the first drain pipe. Drain with the second drain pipe of the
The drain pipe is squeezed to reduce the outflow gas, connected to the first drain pipe, the gas flowing out from these drain pipes and the condensed water are collected, and the condensed water is drained to the drain tank. Since the outflow of water is sealed with water, the condensed water generated in the gas paths around each of the first and second drain pipes can be continuously discharged to a common drain tank. Set the water sealing height of the tank to the lowest pressure at the position of the gas path where each drain pipe is installed.
There is an effect that it can be suppressed to a value corresponding to the gas pressure of the gas path at the position where the drain pipe is provided.

According to the fuel cell power generation facility of the third aspect of the present invention, the first drain pipe is provided in the gas passage downstream of the fuel cell having a low gas pressure in the series of gas passages. There is an effect that the water sealing height of the tank can be suppressed to a value corresponding to the gas pressure in the gas passage downstream of the fuel cell having the lowest pressure in the series of gas passages.

According to the fourth aspect of the fuel cell power generation system of the present invention, the first drain pipe is connected to the gas pipe line for discharging the exhaust gas discharged from the fuel cell, and the second drain pipe is connected to the outlet manifold of the fuel cell. Since each of them is a gas path for exhaust gas from the fuel cell, the amount of outflow gas bypassed from the second drain pipe to the gas path via the first drain pipe and released is slightly increased. However, the effect on the entire fuel cell power generation facility is small, and it is possible to increase the area of the second drain pipe, and it is possible to increase the efficiency of the drainage drained through this pipe. There is.

According to the fifth aspect of the fuel cell power generation system of the present invention, the first drain pipe is connected to the gas pipe line for supplying the fuel gas from the transformer to the fuel cell, and the second drain pipe is connected to the transformer. It is provided in each of the gas pipelines that supply the fuel gas, and since both are gas paths for the fuel gas, the outflow gas that is discharged from the second drain piping through the connecting piping in the first field to the gas path is released. Even if the amount increases a little, it has a small effect on the entire fuel cell power generation facility, and it becomes possible to increase the area of the second drain pipe, which improves the efficiency of drainage drained through this pipe. There is an effect that it becomes possible.

According to the sixth aspect of the fuel cell power generation system of the present invention, the first drain pipe is provided in the gas pipe passage for discharging the exhaust gas discharged from the fuel cell, and the second drain pipe is connected to the transformer. Since the gas piping for supplying the fuel gas, the gas piping for supplying the fuel gas from the transformer to the fuel cell, and the outlet manifold of the fuel cell are respectively provided, the drain piping is provided at the main part of the series of gas paths. , Condensate generated in a series of gas passages can be collectively discharged to a common drain tank, and the water sealing height of the drain tank can be adjusted by the exhaust from the fuel cell with low pressure in the gas passage provided with the drain pipe. There is an effect that the value can be suppressed to a value corresponding to the gas pressure of the gas piping that discharges the gas.

According to the seventh aspect of the fuel cell power generation facility of the present invention, the condensed water generated in the gas passage is taken out by depressurizing the drain pipe together with the outflow gas, and further extracting the gas from the outlet of the drain pipe. Since the outflow is suppressed by the water pressure, the drain can be continuously discharged, and the depth of the water tank of the drain tank can be made shallow, so that the drain tank device can be made small in size.

According to the fuel cell power generation facility of the eighth aspect of the present invention, the condensed water generated in the gas path is drained through the U-shaped drain pipe below the gas path. Drain can be drained continuously,
There is an effect that the drain tank can be reduced in size or eliminated simply by extending the drain pipe that does not take up space.

[Brief description of drawings]

FIG. 1 is a system diagram of a gas and drain system of a fuel cell power generation facility showing a first embodiment of the present invention.

[Fig. 2] Fig. 2 is a cross-sectional configuration diagram of a pipeline of the fuel cell power generation facility showing Embodiment 1 of the present invention.

[Fig. 3] Fig. 3 is a cross-sectional configuration diagram of a pipeline of a fuel cell power generation facility showing another embodiment of the first embodiment of the present invention.

FIG. 4 is a system diagram of a gas and drain system of a fuel cell power generation facility showing Example 2 of the present invention.

FIG. 5 is a system diagram of a gas and drain system of a fuel cell power generation facility showing Example 3 of the present invention.

FIG. 6 is a system diagram of a gas and drain system of a fuel cell power generation facility showing Example 4 of the present invention.

[Fig. 7] Fig. 7 is a cross-sectional configuration diagram of a pipeline of a fuel cell power generation facility showing another embodiment of the fourth embodiment of the present invention.

FIG. 8 is a system diagram showing a gas and drain system of a conventional fuel cell power generation facility.

[Explanation of symbols]

21, 23, 27 Gas pipeline 22 CO shifter 24 Fuel electrode 26 Fuel cell outlet manifold 38 Drain tank 39 Overflow pipe 41, 41a, 41b First drain pipe 42, 42a, 43, 43a, 44, 44a, 44b
Second drain pipe 45 Drain 46 Outflow gas flow 51 First drain pipe 53 Drain tank 54 Overflow pipe 61 Drain pipe 62 Drain tank 63 Vent pipe 64 Overflow pipe 71 Drain pipe 72 Drain tank 73 Overflow pipe 81 Drain pipe

Claims (8)

[Claims] 1. A gas path connected to a series of steps, in which a fuel gas containing water vapor is supplied to a fuel cell, the fuel gas is electrochemically reacted in the fuel cell, and exhaust gas containing water vapor generated thereby is discharged. A first drain pipe that is provided in this gas path and guides and drains condensed water generated in the gas path around it, and at one or more positions upstream of the position where this first drain pipe is provided, Condensed water generated in the gas passages around each of the gas passages is guided and discharged, and a part of the gas in the gas passages is discharged together to suppress the amount of this gas. ,
A second drain pipe having a portion having a cross-sectional area smaller than the cross-sectional area of the gas path at the position where it is provided, and water sealing the gas flowing out from the first drain pipe and the second drain pipe to the outside air, And a drain tank having an overflow part for draining excess water so as to keep the water level constant,
A connecting portion is provided to connect the gas discharged from the first drain pipe and the second drain pipe so as to collect condensed water, and the condensed water is drained to the drain tank, and the second drain is discharged. The gas discharged from the pipe is returned to the gas path via the first drain pipe. 2. A fuel gas containing water vapor is supplied to a fuel cell through a transformer, the fuel gas is electrochemically reacted in the fuel cell, and exhaust gas containing water vapor generated thereby is reformer-combusted. A series of gas passages for discharging to the section, a first drain pipe provided in this gas passage for guiding and discharging condensed water generated in the gas passages around the gas passage, and an outlet of this first drain pipe A drain tank is provided which stores the condensed water and seals the gas outflow from the first drain pipe outlet by water pressure according to the height from the outlet to the water surface, and the water level of this tank. In order to keep it constant, at a drain tank device having an overflow part for draining excess water, and at one or more positions upstream from the position where the first drain pipe is provided,
Condensed water generated in the gas passages around each of the gas passages is guided and discharged, and a part of the gas in the gas passages is discharged together to suppress the amount of this gas. A second drain pipe whose outlet is connected to the first drain pipe, the condensed water having the cross-sectional area smaller than the cross-sectional area of the gas passage at the position where the condensed water is the drain. A fuel cell power generation facility, characterized in that gas discharged to a tank and discharged from the second drain pipe is returned to the gas path via the first drain pipe. 3. The fuel cell power generation facility according to claim 1 or 2, wherein the first drain pipe is provided in a gas path downstream of the fuel cell. 4. The first drain pipe is connected to a gas pipe line for discharging exhaust gas emitted from the fuel cell, and the second drain pipe is connected to an outlet manifold of the fuel cell. The fuel cell power generation facility according to claim 1 or claim 3. 5. The first drain pipe is connected to a gas pipe line for supplying fuel gas from the transformer to the fuel cell, and the second drain pipe is connected to a gas pipe line for supplying fuel gas to the transformer. Claim 1 or Claim 2 characterized in that
Fuel cell power generation facility described. 6. A first drain pipe is connected to a gas pipe line for exhausting exhaust gas emitted from the fuel cell, and a second drain pipe is connected to the gas pipe line for supplying fuel gas to the transformer and the transformer pipe. A gas pipeline for supplying fuel gas to the fuel cell,
The fuel cell power generation equipment according to claim 1 or 2, which is connected to an outlet manifold of the fuel cell. 7. A gas path connected to the fuel cell, the fuel gas containing water vapor is supplied to the fuel cell, the fuel gas is electrochemically reacted in the fuel cell, and exhaust gas containing water vapor generated by the electrochemical reaction is discharged. In order to guide and discharge condensed water generated in this gas path, the drain path is provided in the gas path, has a portion having a cross-sectional area smaller than the gas path, and provided at the outlet of the drain piping, A drain tank that stores condensed water and resists the pressure at the outlet of the drain pipe, and controls the gas outflow from the outlet by water pressure according to the height from this outlet to the water surface, and flows out from the outlet. A drain tank device having a vent pipe for discharging gas to the outside and an overflow part for draining surplus water so as to keep the water level of this tank constant was provided. A fuel cell power generation facility characterized by the above. 8. A gas path connected in series to supply a fuel gas containing water vapor to a fuel cell, to cause an electrochemical reaction of the fuel gas in the fuel cell, and to discharge exhaust gas containing water vapor generated thereby. And a drain pipe provided in the gas passage for guiding and discharging condensed water generated in the gas passage and having a U-shaped curved portion below the gas passage, and the bottom of the drain pipe. A fuel cell power generation facility, characterized in that the gas outflow from the drain pipe is water-sealed with water pressure according to the height from the drain pipe to the drain outlet of the drain.