JP7457561B2 - fuel cell power generator - Google Patents

Description

Embodiments of the present invention relate to a fuel cell power generation device and a method of operating the same.

In a fuel cell power generation device, ion exchange water is used as cooling water to cool the fuel cell and the like. An example of a water quality control device for controlling the quality of cooling water is an ion exchange resin bottle filled with a cation exchange resin and an anion exchange resin.

The ion exchange resin has the property of being decomposed at high temperatures. If the ion exchange resin decomposes, the quality control of the cooling water will become insufficient. Therefore, a method of periodically replacing the ion exchange resin bottle may be considered.

However, since the ion exchange resin bottle is usually cooled by the outside air, for example, in the summer when the outside air temperature is high, there is a high possibility that the ion exchange resin bottle will reach a high temperature state before it is time to replace it.

Patent No. 4891487

The problem to be solved by the present invention is to provide a fuel cell power generation device and a method of operating the same that can use an ion exchange resin at high temperature for a long time.

A fuel cell power generation device according to an embodiment includes a cathode to which an oxygen-containing gas is supplied, an anode to which a hydrogen-containing gas is supplied, and a cooling water that cools the heat generated by the reaction between the oxygen-containing gas and the hydrogen-containing gas. a cooling unit to which cooling water is supplied, a water tank storing cooling water, an ion exchange resin bottle filled with ion exchange resin, and cooling water flowing between the water tank and the ion exchange resin bottle. A recycle blower that increases the pressure of the gas discharged from the anode, and a first pipe that connects the recycle blower and a cooling water circulation path.

According to this embodiment, it becomes possible to use the ion exchange resin at high temperature for a long time.

FIG. 1 is a block diagram of a fuel cell power generation device according to a first embodiment. FIG. 2 is a block diagram of a fuel cell power generation device according to a second embodiment. FIG. 13 is a block diagram showing an example of the configuration of a fuel cell power generation device according to a third embodiment. FIG. 13 is a block diagram showing an example of the configuration of a fuel cell power generation device according to a fourth embodiment. It is a block diagram showing an example of composition of a fuel cell power generation device concerning a 5th embodiment. It is a block diagram showing an example of composition of a fuel cell power generation device concerning a 6th embodiment.

The fuel cell power generation device according to the embodiment of the present invention will be described in detail below with reference to the drawings. Note that the embodiment shown below is one example of the embodiment of the present invention, and the present invention is not limited to these embodiments. In addition, in the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same or similar symbols, and repeated explanations may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for the convenience of explanation, and some components may be omitted from the drawings. The fuel cell power generation device is a system that converts hydrogen directly into electrical energy in the fuel cell main body. This system generates electricity through chemical reactions, so it has high power generation efficiency, emits little pollutants and makes little noise, and is evaluated as an environmentally friendly power generation device.

(First embodiment)
FIG. 1 is a block diagram showing a configuration example of a fuel cell power generation device according to a first embodiment. In the fuel cell power generation device shown in FIG. 1, a fuel cell main body 1 generates power using an oxygen-containing gas 1a such as air and a hydrogen-containing gas 1b. The fuel cell main body 1 includes a cathode 1c, an anode 1d, a cooling section 1e, and an ion conductive layer (not shown).

An oxygen-containing gas 1a is supplied to the cathode 1c, and a hydrogen-containing gas 1b is supplied to the anode 1d. The cooling unit 1e cools the reaction heat generated by the reaction between the oxygen-containing gas 1a and the hydrogen-containing gas 1b via the ion-conducting layer with a coolant 1f, such as cooling water. The substance constituting the ion conductive layer is, for example, a cation exchange resin, an acidic solution, an alkaline solution, a molten carbonate, a zirconia ceramic, or the like.

In the gas discharged from the outlet of the cathode 1c, oxygen is consumed by the power generation of the fuel cell main body 1, and the oxygen concentration is reduced. This gas is introduced into the water tank 2 and discharged after collecting condensed water from the gas in the water tank 2. Therefore, during operation, the gas phase of the water tank 2 is purged with a gas having a lower oxygen concentration than the oxygen-containing gas 1a, such as air.

The cooling water discharged from the cooling section 1e undergoes heat exchange with the heat exchanger 5. The cooling water is then discharged into the water tank 2 by the pump 6. The heat exchanger 5 may be installed downstream of the pump 6 and upstream of the water tank 2. Further, a part of the water stored in the water tank 2 is again supplied to the cooling unit 1e as a refrigerant 1f. Thereby, a cooling water circulation path is formed between the cooling part 1e and the water tank 2.

The gas discharged from the outlet of the anode 1d is pressurized by the recycle blower 3. The pressurized bleed gas passes through the recycle line orifice 3a. Thereafter, this gas merges with the supply piping for the hydrogen-containing gas 1b at the junction j10. The line that returns to the junction j10 from the junction j10 through the anode 1d, the recycle blower 3, and the recycle line orifice 3a is referred to as a recycle line 3b.

If the pressure of the merging portion j10 is maintained constant by adjusting the supply pressure of the hydrogen-containing gas 1b, the amount of hydrogen consumed by the anode 1d and the amount of hydrogen supplied by the hydrogen-containing gas 1b match. As a result, it is possible to operate without discharging the gas discharged from the anode 1d to the outside during most of the period during power generation operation. However, the concentration of impurities such as nitrogen that is not consumed in the fuel cell main body 1 increases with time, and this may affect the operation of the fuel cell main body 1.

Therefore, the piping is branched from a branch j11 provided downstream of the recycle blower 3. Furthermore, a bleed valve 3c is provided downstream of the piping. By periodically opening the bleed valve 3c for a certain period of time, impurities in the recycle line 3b are purged with bleed gas.

Further, in this embodiment, a bleed orifice 3d is provided downstream of the bleed valve 3c in order to prevent the flow rate of the bleed gas from becoming excessive. Furthermore, when the bleed valve 3c is opened, the flow rate that flows backward through the recycle line from the confluence part j10 to the branch j11 is greater than the flow rate of the forward flow from the confluence part j10, passing through the anode 1d and the recycle blower 3, and reaching the branch j11. A recycle line orifice 3a is provided in order to adjust the temperature so that it does not become excessive.

Pure water is stored in the water tank 2 as the cooling water. The water level 2a of pure water in the water tank 2 is maintained below a certain level by a drainage facility (not shown). In order to maintain water quality, a portion of the pure water stored in the water tank 2 is drawn out from the bottom surface of the water tank 2 by a pump 4f. The pump 4f sends out the derived pure water to the lower surface of the ion exchange resin bottle 4 through a pipe 4g (second pipe). Pure water is ion-exchanged within the ion-exchange resin bottle 4. The ion-exchanged pure water is discharged from the top of the ion-exchange resin bottle 4 and returned to the water tank 2. In this way, a pure water circulation path 4e is configured between the water tank 2 and the ion exchange resin bottle 4.

The ion exchange resin bottle 4 is filled with a cation exchange resin and an anion exchange resin, which are spherical particles having a diameter of 1 mm or less, as an ion exchange resin 4d. The ion exchange resin 4d is not filled over the entire length of the ion exchange resin bottle 4. An inlet space 4a is provided on the inlet side of the ion exchange resin bottle 4, and an outlet space 4b is provided on the outlet side.

The heat resistant temperature of the cation exchange resin is around 120°C, and the heat resistant temperature of the anion exchange resin is around 60°C. When these heat-resistant temperatures are exceeded, cation exchange resins have the property of releasing sulfonic acid compounds, and anion exchange resins have the property of releasing amine compounds. However, when a fuel cell power generator is actually operated, the cation exchange resin may decompose at a lower temperature than the anion exchange resin. The reason for this is that an oxidation reaction of the cation exchange resin occurs due to dissolved oxygen present in the water surrounding the cation exchange resin.

Therefore, in this embodiment, a pipe 3e (first pipe) for introducing the bleed gas into the ion exchange resin bottle 4 is provided. One end of the pipe 3e is connected to the pipe 4g at a branch j12. The other end of the pipe 3e is connected to the outlet of the bleed orifice 3d. Thereby, the outlet of the bleed orifice 3d and the branch j12 can be connected by the pipe 3e. The piping connecting the top surface of the ion exchange resin bottle 4 and the water tank 2 may be opened either above or below the water level 2a, but if it is opened below, it will not interfere with the flow of bleed gas, which will be described later. Therefore, it is desirable that the distance from the water level 2a is, for example, within 5 cm.

Note that the pump 4f and the ion exchange resin bottle 4 are desirably arranged vertically below the water level 2a of the water tank 2. This is because, in the case of such an arrangement, the pump 4f and the ion exchange resin bottle 4 are filled with water from the water tank 2 when the power generation operation is stopped. In order to be able to fill with water from the water tank 2 when the operation is stopped, it is preferable that the pump 4f be a spiral type or whirlpool type pump rather than a piston type or other pump with a closing function.

On the other hand, it is desirable to place the recycle blower 3, recycle line orifice 3a, bleed valve 3c, and bleed orifice 3d above the water level 2a so as not to be submerged. The desirable height of the fuel cell main body 1 relative to the water level 2a depends on the characteristics of the fuel cell main body 1, but in this embodiment, they are placed below the water level 2a.

In this embodiment, when the fuel cell main body 1 generates electricity, impurities other than hydrogen increase in the recycle line 3b during the period when the bleed valve 3c is closed, so the bleed valve 3c is periodically opened for a certain period of time to purge the gas with increased impurities with hydrogen-containing gas 1b, which has a high hydrogen concentration.

The bleed gas, which is mainly composed of hydrogen and nitrogen and does not contain oxygen, discharged from the bleed valve 3c through the bleed orifice 3d enters the pipe 4g at a branch j12, and is temporarily stored in the inlet space 4a of the ion exchange resin bottle 4. Ru. While the bleed gas is stored in the inlet space 4a, the pump 4f is operated and pure water from the water tank 2 is pushed into the ion exchange resin bottle 4, so that the bleed gas that has entered the inlet space 4a is pushed up and filled. It passes through the ion exchange resin 4d. During the process in which the bleed gas passes through the ion exchange resin 4d, dissolved oxygen adsorbed on the surface of the ion exchange resin 4d is purged. This suppresses decomposition of the ion exchange resin 4d.

The bleed gas that has passed through the ion exchange resin 4d enters the outlet space 4b of the ion exchange resin bottle 4, and is led out from the top surface of the ion exchange resin bottle 4 into the water tank 2. The gas led out to the water tank 2 is diluted by the gas discharged from the outlet of the cathode 1c and then discharged.

According to the embodiment described above, the bleed gas that is periodically discharged from the recycle line 3b of the fuel cell and pressurized by the recycle blower 3 is introduced into the ion exchange resin bottle 4. This bleed gas can reduce dissolved oxygen in the ion exchange resin 4d, which can particularly oxidize and decompose the cation exchange resin. Therefore, it becomes possible to use the ion exchange resin at high temperature for a long time.

In this embodiment, the bleed gas discharged from the ion exchange resin bottle 4 is diluted in the water tank 2 and then exhausted to the outside, so safety can be ensured. Even if a fire were to ignite within the water tank 2, the combustion would not reach the recycle line 3b or the anode 1d because the water is sealed with the ion exchange resin bottle 4.

Second Embodiment
Fig. 2 is a block diagram showing a configuration example of a fuel cell power generation device according to the second embodiment. In this embodiment, as shown in Fig. 2, there is no branch j12, and the pipe 3e connected to the outlet of the bleed orifice 3d is directly connected to the bottom surface of the ion exchange resin bottle 4. Therefore, the bleed gas is directly introduced into the inlet space 4a, so that the dissolved oxygen in the ion exchange resin bottle 4 can be reduced with a simpler pipe configuration than in the first embodiment.

Note that in this embodiment, since the branch j12 is not required, the piping configuration is simpler than in the first embodiment. Also in this embodiment, in order to charge the pump 4f and the ion exchange resin bottle 4 with water when the operation is stopped, it is desirable to arrange these devices below the water level 2a.

Third Embodiment
FIG. 3 is a block diagram showing an example of the configuration of a fuel cell power generating apparatus according to the third embodiment.

In this embodiment, the configuration and operation of the peripheral devices of the fuel cell main body 1 and the devices of the recycle line 3b are similar to those of the first and second embodiments described above, so a description thereof will be omitted. In this embodiment, too, it is desirable to place the pump 4f and the ion exchange resin bottle 4 below the water level 2a of the water tank 2.

On the other hand, in the ion exchange resin bottle 4 of this embodiment, the inlet space 4a is arranged vertically above, and the outlet space 4b is arranged vertically below. Further, pure water drawn out from the lower surface of the water tank 2 by the pump 4f enters from the upper surface of the ion exchange resin bottle 4, exits from the lower surface, and returns to the lower surface of the water tank 2. Furthermore, an ion exchange resin bottle vent orifice 4c is connected to the upper surface of the ion exchange resin bottle 4, and a connecting pipe is provided between the ion exchange resin bottle vent orifice 4c and the water tank 2.

The above connecting pipe may be opened either above or below the water level 2a, but since the differential pressure between the ion exchange resin bottle vent orifice 4c and the water tank 2 is low and the pipe is easily blocked by air bubbles, the connecting pipe It is desirable that the inner diameter is, for example, 6 mm or more.

Furthermore, since air bubbles tend to accumulate before and after the ion exchange resin bottle air vent orifice 4c, it is desirable that the ion exchange resin bottle air vent orifice 4c be installed at a position higher than the water level 2a.

In the fuel cell power generation device of this embodiment, the pump 4f stops operating at the same time as the bleed valve 3c opens. Therefore, the bleed gas discharged from the bleed valve 3c enters the pipe 4g from the pipe 3e and rises inside the pipe 4g. The bleed gas then enters the outlet space 4b from the bottom of the ion exchange resin bottle 4 and passes through the ion exchange resin 4d. The bleed gas then flows from the inlet space 4a into the water tank 2 through the ion exchange resin bottle vent orifice 4c.

While the bleed valve 3c is open, the flow direction of the bleed gas is opposite to the liquid delivery direction of the pump 4f (see the arrow in Figure 3), so it is desirable to stop the pump 4f. The pump 4f resumes operation after the bleed valve 3c is closed. At this time, pure water is pushed in from the top surface of the ion exchange resin bottle 4, and the bleed gas remaining in the inlet space 4a of the ion exchange resin bottle 4 is sent from the ion exchange resin bottle vent orifice 4c into the water tank 2. By operating in this manner, it is possible to reduce the dissolved oxygen in the ion exchange resin 4d, which poses a risk of oxidative decomposition, especially of the cation exchange resin.

Further, the bleed gas discharged from the ion exchange resin bottle 4 is diluted in the water tank 2 and then exhausted to the outside, as in other embodiments, so safety can be ensured. Even if a fire were to ignite within the water tank 2, the combustion would not reach the recycle line 3b or the anode 1d because the water is sealed with the ion exchange resin bottle 4. During this process, there is a possibility that a part of the bleed gas may directly flow from the branch j12 into the water tank 2 through the pipe 4g without passing through the ion exchange resin bottle 4. However, reducing the dissolved oxygen in the water tank 2 located upstream of the ion exchange resin bottle 4 will lead to a reduction in dissolved oxygen in the ion exchange resin bottle 4, so there is no need to provide a means to stop the inflow, such as a shutoff valve. do not have.

This embodiment can be applied to cases where it is required to make the internal flow a downward flow from the top to the bottom in order to suppress the flow of the ion exchange resin 4d inside the ion exchange resin bottle 4.

(Fourth embodiment)
FIG. 4 is a block diagram showing a configuration example of a fuel cell power generation device according to a fourth embodiment. Hereinafter, differences from the third embodiment will be mainly described.

In this embodiment, the branch j12 does not exist, and the pipe 3e connected to the outlet of the bleed orifice 3d is directly connected to the lower surface of the ion exchange resin bottle 4. Therefore, the bleed gas is introduced directly into the outlet space 4b. Therefore, compared to the third embodiment, dissolved oxygen in the ion exchange resin bottle 4 can be reduced with a simpler piping configuration. In addition, it is also possible to reduce the proportion of bleed gas that does not pass through the ion exchange resin bottle 4 and directly flows into the water tank 2 compared to the third embodiment.

In addition, in this embodiment, as in the third embodiment, it is desirable that the pump 4f and the ion exchange resin bottle 4 are arranged below the water level 2a, and the ion exchange resin bottle air vent orifice 4c is arranged below the water level 2a. It is desirable to place it in a higher position.

(Fifth embodiment)
FIG. 5 is a block diagram showing a configuration example of a fuel cell power generation device according to a fifth embodiment.

In this embodiment, the configurations of the peripheral equipment of the fuel cell main body 1, the equipment of the recycle line 3b, the pump 4f, and the ion exchange resin bottle 4 are the same as those of the first embodiment, and therefore the description thereof will be omitted. Further, the flow of pure water in the ion exchange resin bottle 4 is also from vertically downward to vertically upward, similarly to the first embodiment.

In this embodiment, there is no branch j12, and the pipe 3e connected to the outlet of the bleed orifice 3d is connected to the lower surface of the water tank 2. In this configuration, the bleed gas discharged from the outlet of the bleed orifice 3d does not directly flow to the ion exchange resin bottle 4, but foams in the water tank 2 disposed upstream thereof. Thereafter, the bleed gas is diluted by the gas discharged from the cathode 1c flowing in the water tank 2 and introduced into the water tank 2, and then discharged to the outside.

Since dissolved oxygen in the water tank 2 is reduced by the flow of the bleed gas, dissolved oxygen in the ion exchange resin bottle 4 downstream thereof is also reduced.

Note that the opening position of the pipe connecting the ion exchange resin bottle 4 to the water tank 2 in the water tank 2 was desirably above the water level 2a in the first and second embodiments. On the other hand, in this embodiment, the opening position is not limited, and the opening may be made on the lower surface of the water tank 2. This is because the bleed gas does not flow inside the ion exchange resin bottle 4, so there is no risk that the flow of the bleed gas will be inhibited by the water head pressure applied to the opening.

Further, as shown in FIG. 5, the piping 4g connecting the pump 4f and the inlet of the ion exchange resin bottle 4 is raised to a position higher than the water level 2a of the water tank 2 and then lowered to a position lower than the water level 2a again. It is also possible to have a bent configuration. In such a configuration, by making the portion of the pipe 4g higher than the water level 2a removable, the ion exchange resin bottle 4 can be replaced without leaking the pure water stored in the water tank 2.

Furthermore, with this configuration, no bleed gas remains in the ion exchange resin bottle 4 after the pump 4 is stopped, and water does not escape as long as the inlet and outlet from the water tank 2 are at positions lower than the water level 2a. Therefore, it is not necessary to arrange the entire ion exchange resin bottle 4 below the water level 2a, and it can also be arranged at a position higher than the water level 2a, as shown in FIG.

Sixth Embodiment
FIG. 6 is a block diagram showing an example of the configuration of a fuel cell power generation device according to the sixth embodiment.

In this embodiment, the peripheral equipment of the fuel cell main body 1, the equipment of the recycle line 3b, and the configurations of the pump 4f and the ion exchange resin bottle 4 are the same as in the third embodiment. Further, the flow of pure water in the ion exchange resin bottle 4 is also from vertically upward to vertically downward, as in the third embodiment.

Further, in this embodiment, the pipe 3e connected to the outlet of the bleed orifice 3d is connected to the lower surface of the water tank 2, similarly to the fifth embodiment. Therefore, dissolved oxygen in the pure water in the water tank 2 is reduced by the bleed gas supplied through the pipe 3e. Moreover, since the pure water with reduced dissolved oxygen flows through the ion exchange resin bottle 4 by the pump 4f, the dissolved oxygen in the ion exchange resin bottle 4 is also reduced.

The opening position of the pipe connecting the outlet of the ion exchange resin bottle vent orifice 4c to the water tank is not limited as in the fifth embodiment, and may open on the underside of the water tank 2. Furthermore, as in the fifth embodiment, the pipe 4g is also bent at a position higher than the water level 2a and then bent at a position lower than the water level 2a, making the part of the pipe 4g higher than the water level 2a removable, and thus making it possible to replace the ion exchange resin bottle 4 without leaking the pure water stored in the water tank 2.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1: Fuel cell body, 1a: Oxygen-containing gas, 1b: Hydrogen-containing gas, 1c: Cathode, 1d: Anode, 1e: Cooling section, 1f: Coolant (cooling water), 2: Water tank, 2a: Water level, 3: Recycle blower, 3a: Recycle line orifice, 3b: Recycle line, 3c: Bleed valve, 3d: Bleed orifice, 4: Ion exchange resin bottle, 4a: Inlet space, 4b: Outlet space, 4c: Ion exchange resin bottle vent orifice, 4d: Ion exchange resin, 4e: Circulation flow path, 4f: Pump

Claims (8)

A cathode to which an oxygen-containing gas is supplied, an anode to which a hydrogen-containing gas is supplied, and a cooling section to which cooling water is supplied to cool the heat generated by the reaction between the oxygen-containing gas and the hydrogen-containing gas. a fuel cell main body having;
a water tank that stores the cooling water;
An ion exchange resin bottle filled with ion exchange resin,
a pump that circulates the cooling water between the water tank and the ion exchange resin bottle;
a recycle blower that boosts the pressure of the gas discharged from the anode;
a first pipe connecting the recycle blower and the cooling water circulation flow path;
Equipped with
A fuel cell power generation device , wherein one end of the first pipe is connected to a second pipe provided between the water tank and the ion exchange resin bottle or to a lower surface of the ion exchange resin bottle. The ion exchange resin bottle is arranged below the water level of the cooling water in the water tank, and the flow direction of the cooling water in the ion exchange resin bottle is from the bottom surface to the top surface of the ion exchange resin bottle. The fuel cell power generation device according to claim 1 , wherein the fuel cell power generation device is in the direction. The fuel cell power generation device according to claim 2 , further comprising a bleed cutoff valve provided between the other end of the first pipe and the recycle blower, the bleed cutoff valve being open when the pump is driven. . the ion exchange resin bottle is disposed below the water level of the cooling water in the water tank, and the flow direction of the cooling water in the ion exchange resin bottle is a direction from an upper surface to a lower surface of the ion exchange resin bottle,
2. The fuel cell power generation system according to claim 1 , further comprising an orifice provided between said upper surface and said water tank, said orifice being located above said water level. 5. The pump according to claim 4 , further comprising a bleed cutoff valve provided between the other end of the first pipe and the recycle blower, and the bleed cutoff valve opens when the pump is stopped and closes when the pump is driven. fuel cell power generation device. A cathode to which an oxygen-containing gas is supplied, an anode to which a hydrogen-containing gas is supplied, and a cooling section to which cooling water is supplied to cool the heat generated by the reaction between the oxygen-containing gas and the hydrogen-containing gas. a fuel cell main body having;
a water tank that stores the cooling water;
An ion exchange resin bottle filled with ion exchange resin,
a pump that circulates the cooling water between the water tank and the ion exchange resin bottle;
a recycle blower that boosts the pressure of the gas discharged from the anode;
a first pipe connecting the recycle blower and the cooling water circulation flow path;
Equipped with
A fuel cell power generation device, wherein one end of the first pipe is connected to a lower surface of the water tank. 7. The fuel cell power generation device according to claim 6 , wherein the flow direction of the cooling water in the ion exchange resin bottle is from the bottom surface to the top surface of the ion exchange resin bottle. Further comprising an orifice provided between the upper surface of the ion exchange resin bottle and the lower surface of the water tank, the orifice being located above the water level of the cooling water in the water tank. The fuel cell power generation device according to claim 7 .

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