JP2014216062A - Secondary battery type fuel cell system and power supply system including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery type fuel cell system capable of improving responsiveness immediately after changing of power generation operation to charging operation.SOLUTION: A secondary battery type fuel cell system includes: a hydrogen generation section; a power generation/electrolysis section having a power generation function for generating power with hydrogen supplied from the hydrogen generation section and an electrolysis function for electrolyzing of water vapor supplied from the hydrogen generation section at reproduction of the hydrogen generation section; a gas flow passage for circulating gas containing hydrogen and water vapor between the hydrogen generation section and the power generation/electrolysis section; a circulation section for forcibly circulating gas containing hydrogen and water vapor between the hydrogen generation section and the power generation/electrolysis section; and a gas flow passage control section for controlling the gas flow passage. The gas flow passage control section controls the gas flow passage so as to suppress circulation of the gas by the gas flow passage when an operation of the system is switched from power generation operation to charging operation.

Description

  The present invention relates to a secondary battery type fuel cell system capable of performing not only a power generation operation but also a charging operation, and a power supply system including the same.

  A fuel cell typically includes a solid polymer electrolyte membrane using a solid polymer ion exchange membrane, a solid oxide electrolyte membrane using yttria-stabilized zirconia (YSZ), a fuel electrode (anode) and an oxidizer electrode. The one sandwiched from both sides by the (cathode) has a single cell configuration. A fuel gas channel for supplying a fuel gas (for example, hydrogen) to the fuel electrode and an oxidant gas channel for supplying an oxidant gas (for example, oxygen or air) to the oxidant electrode are provided. Electric power is generated by supplying the fuel gas and the oxidant gas to the fuel electrode and the oxidant electrode, respectively.

  Fuel cells are not only energy-saving because of the high efficiency of the power energy that can be extracted in principle, but they are also a power generation system that excels in the environment, and are expected as a trump card for solving global energy and environmental problems.

Japanese National Patent Publication No. 11-501448 International Publication No. 2012/098945

  Patent Document 1 and Patent Document 2 disclose a secondary battery type fuel cell system that combines a solid oxide fuel cell and a hydrogen generating member that generates hydrogen by an oxidation reaction and can be regenerated by a reduction reaction. Yes. In the secondary battery type fuel cell system, the hydrogen generating member generates hydrogen during the power generation operation of the system, and the hydrogen generating member is regenerated during the charging operation of the system.

  The secondary battery type fuel cell system disclosed in Patent Document 1 is a system in which the space where the fuel electrode of the fuel cell unit and the hydrogen generating member are sealed is not a closed space, and always requires replenishment of water. It is.

  On the other hand, in the secondary battery type fuel cell system disclosed in Patent Document 2, the space where the fuel electrode of the fuel cell portion and the hydrogen generating member are sealed is a closed space, Since the power generation operation of the system and the charging operation of the system are performed using the existing mixed gas of hydrogen and water vapor, the system basically does not require replenishment of water.

  In the secondary battery type fuel cell system disclosed in Patent Document 2, the gas generated by the equilibrium reaction of the hydrogen generating member is used for the power generation reaction during the power generation operation of the system and the electrolysis reaction during the charging operation of the system. . The composition of the gas generated by the equilibrium reaction of the hydrogen generating member is constant during both the power generation operation and the charging operation of the system (for example, the hydrogen generating member is a member mainly made of iron and heated to 600 ° C. If so, hydrogen: water vapor = 3: 1).

  For this reason, even when hydrogen used in the power generation reaction is sufficiently supplied from the hydrogen generation member during the power generation operation of the system, water vapor used in the electrolysis reaction is sufficiently supplied from the hydrogen generation member during the charging operation of the system. Will not be.

  The amount of water vapor supplied from the hydrogen generating member can be increased by increasing the temperature of the hydrogen generating member or increasing the gas circulation rate when the system is charged compared to when the system is generating power. It takes some time for the water vapor supply amount from the hydrogen generating member to actually increase after the temperature of the gas is increased or the gas circulation rate is increased.

  For example, when the secondary battery type fuel cell system disclosed in Patent Document 2 is used as a system power stabilization means when a natural energy power generation facility (solar power generation facility, wind power generation facility, etc.) is introduced, the natural energy power generation facility When the power generation amount of the secondary battery type fuel cell system falls below a predetermined value, the secondary battery type fuel cell system disclosed in Patent Document 2 generates the power (insufficient power) below that amount, and the power generation amount of the natural energy power generation facility is a predetermined value. If it exceeds the above, the secondary battery type fuel cell system disclosed in Patent Document 2 will charge the excess power (surplus power).

  In this case, immediately after the power generation operation of the secondary battery type fuel cell system disclosed in Patent Document 2 is switched to the charging operation, the secondary battery type fuel cell system disclosed in Patent Document 2 generates excess power. Since it cannot fully charge, a part of surplus electric power becomes heat and is wasted, or system electric power fluctuates.

  In view of the above situation, an object of the present invention is to provide a secondary battery type fuel cell system capable of improving responsiveness immediately after switching from a power generation operation to a charging operation, and a power supply system including the same. .

  In order to achieve the above object, a secondary battery type fuel cell system according to the present invention can release hydrogen by an oxidation reaction and can be regenerated by a reduction reaction, and is supplied from the hydrogen generation unit. A power generation / electrolysis unit having a power generation function for generating power using hydrogen and an electrolysis function for electrolyzing water vapor supplied from the hydrogen generation unit during regeneration of the hydrogen generation unit, the hydrogen generation unit, and the power generation / A gas flow path for circulating a gas containing hydrogen and water vapor to and from the electrolysis unit, and a gas containing hydrogen and water vapor are forcibly circulated between the hydrogen generation unit and the power generation / electrolysis unit. A secondary battery type fuel cell system comprising a circulation unit and a gas channel control unit for controlling the gas channel, wherein the gas channel control unit switches the operation of the system from a power generation operation to a charging operation. When that has a configuration for controlling the gas flow path so as to suppress the circulation of gas by the gas flow path (first configuration). The power generation / electrolysis unit electrolyzes, for example, a power generation operation that generates power using hydrogen supplied from the hydrogen generation unit and water vapor supplied from the hydrogen generation unit during regeneration of the hydrogen generation unit. For example, the fuel cell may be configured to switch between the electrolysis operation and the fuel cell that generates power using hydrogen supplied from the hydrogen generation unit, and the hydrogen at the time of regeneration of the hydrogen generation unit. The structure separately provided with the electrolyzer which electrolyzes the water vapor | steam supplied from a generation | occurrence | production part may be sufficient.

  In the secondary battery type fuel cell system of the first configuration, the gas flow path control unit includes a valve disposed on the gas flow path and downstream of the gas generation / electrolysis unit on the gas outflow side. It is good also as a structure (2nd structure).

  In the secondary battery type fuel cell system having the second configuration, the opening degree of the valve may be temporarily reduced (third configuration) when the operation of the system is switched from the power generation operation to the charging operation. .

  In the secondary battery type fuel cell system of the third configuration, when the operation of the system is switched from the power generation operation to the charging operation, while the opening of the valve is temporarily reduced, the circulation unit forcibly It is good also as a structure (4th structure) which reduces the amount of circulation of the gas circulated through.

  In the secondary battery type fuel cell system of any one of the first to fourth configurations, the power generation / electrolysis unit includes a fuel cell unit that generates power using hydrogen supplied from the hydrogen generation unit, and An electrolyzer that electrolyzes water vapor supplied from the hydrogen generator during regeneration of the hydrogen generator, and the electrolyzer is arranged downstream of the gas outflow side of the fuel cell unit (first 5 configuration).

  In the secondary battery type fuel cell system having the first configuration, a gas containing hydrogen and water vapor is circulated between the gas outflow side and the gas inflow side of the power generation / electrolysis unit without passing through the hydrogen generation unit. The gas flow path control unit may include a valve that controls the bypass gas flow path (sixth structure).

  In the secondary battery type fuel cell system of the sixth configuration, the valve temporarily opens the bypass gas passage when the system operation is switched from the power generation operation to the charging operation (seventh configuration). It is good.

  In the secondary battery type fuel cell system of the sixth or seventh configuration, the circulation part is on the gas flow path, and the gas outflow side of the power generation / electrolysis part and the gas in the bypass gas flow path It is good also as a structure (8th structure) arrange | positioned between the inflow side or between the gas outflow side of the said bypass gas flow path, and the gas inflow side of the said electric power generation and electrolysis part.

  In order to achieve the above object, a power feeding system according to the present invention generates power using the secondary battery type fuel cell system having any one of the first to eighth configurations and natural energy, and A power generation facility that supplies power to the secondary battery type fuel cell system (a ninth configuration) is provided.

  According to the present invention, when the operation of the secondary battery type fuel cell system is switched from the power generation operation to the charging operation, the gas for circulating the gas containing hydrogen and water vapor between the hydrogen generation unit and the power generation / electrolysis unit Since the circulation of gas through the flow path is suppressed, the water vapor generated in the power generation / electrolysis section during the power generation operation of the secondary battery type fuel cell system is switched during the charging operation of the secondary battery type fuel cell system to perform the electrolysis. It is possible to promote the supply to the power generation / electrolysis section that is being performed without going through the hydrogen generation section. As a result, it is possible to increase the water vapor supplied to the power generation / electrolysis unit immediately after the operation of the secondary battery type fuel cell system is switched from the power generation operation to the charging operation, and immediately after the power generation operation is switched to the charging operation. Responsiveness can be improved.

It is a mimetic diagram showing a schematic structure of an electric supply system concerning a 1st embodiment of the present invention. It is a time chart which shows operation | movement of the valve | bulb which concerns on 1st Embodiment. It is a figure which shows the flow of the gas at the time of electric power generation operation | movement of a secondary battery type fuel cell system. It is a figure which shows the gas flow immediately after switching from the electric power generation operation | movement of a secondary battery type fuel cell system to charge operation. It is a time chart which shows other operation | movement of the valve | bulb which concerns on 1st Embodiment. It is a time chart which shows other operation | movement of the valve | bulb which concerns on 1st Embodiment. It is a time chart which shows other operation | movement of the valve | bulb which concerns on 1st Embodiment. It is a schematic diagram which shows schematic structure of the electric power feeding system which concerns on 2nd Embodiment of this invention. It is a time chart which shows operation | movement of the valve | bulb which concerns on 2nd Embodiment. It is a schematic diagram which shows schematic structure of the electric power feeding system which concerns on 3rd Embodiment of this invention. It is a time chart which shows operation | movement of the valve | bulb which concerns on 3rd Embodiment. It is a schematic diagram which shows schematic structure of the fuel cell part which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows schematic structure of the fuel cell part which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows schematic structure of the electric power feeding system which concerns on 5th Embodiment of this invention. It is a schematic diagram which shows schematic structure of the electric power feeding system which concerns on 6th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not restricted to embodiment mentioned later. For example, a plurality of embodiments may be combined as appropriate, the examples and modifications described in one embodiment may be applied to other embodiments, and the examples and modifications described in the same embodiment may be applied. These may be combined as appropriate.

<First Embodiment>
FIG. 1 shows a schematic configuration of a power feeding system according to the first embodiment of the present invention. The power supply system according to the present embodiment includes a natural energy power generation facility 100 such as a wind power generation facility that generates power using wind energy or a solar power generation facility that generates power using solar energy, and a secondary battery type fuel cell. The system 200 is provided, and the power output from the secondary battery type fuel cell system 200 is supplied to the power system.

  Natural energy is known to change in a complex manner. For example, in the case of solar energy, short-term changes in the amount of solar radiation due to the movement of clouds and long-term changes in the amount of solar radiation due to the season occur, and in the case of wind energy, sudden changes occur frequently.

  Therefore, in the power supply system according to the present invention, when the amount of power generated by the natural energy power generation facility 100 falls below a predetermined value, the secondary battery type fuel cell system 200 generates the amount of power (insufficient power) below that amount, and the natural energy. When the power generation amount of the power generation facility 100 exceeds a predetermined value, the secondary battery type fuel cell system 200 charges the surplus power (surplus power) and the power generation amount of the natural energy power generation facility 100 matches the predetermined value. The secondary battery type fuel cell system 200 stops power generation and charging. Thereby, the power output from the secondary battery type fuel cell system 200 to the power system can be maintained at a predetermined value, and the power system becomes unstable due to the power output from the secondary battery type fuel cell system 200 to the power system. Can be prevented. It should be noted that the predetermined value described above may have a certain range to be a predetermined range.

  The secondary battery type fuel cell system 200 includes a hydrogen generating member 1, a fuel cell unit 2, a heater 3 for heating the hydrogen generating member 1, a heater 4 for heating the fuel cell unit 2, the hydrogen generating member 1 and the heater. 3, a container 6 housing the fuel cell unit 2 and the heater 4, a pipe 7 for circulating a gas containing hydrogen and water vapor between the hydrogen generating member 1 and the fuel cell unit 2, hydrogen A pump 8 forcibly circulating gas between the generating member 1 and the fuel cell unit 2, a valve 9, a pipe 10 for supplying air to the air electrode 2 </ b> C of the fuel cell unit 2, A pipe 11 for discharging air from the air electrode 2 </ b> C, a power generation charging control unit 12, and a system controller 13 for controlling the entire secondary battery type fuel cell system 200 are provided.

  When the pump 8 operates, the gas in the pipe 7 circulates in the direction of the arrow (clockwise) shown in FIG. The valve 9 is on the pipe 7 and is arranged downstream of the fuel cell unit 2 on the gas outflow side.

  The power generation charging control unit 12 combines the output of the fuel cell unit 2 and the output of the natural energy power generation facility 100 during the power generation operation of the secondary battery type fuel cell system 200, and the combined output has a frequency suitable for the power system. After converting to AC output, output to the power system. The power generation charging control unit 12 smoothes a part of the output of the natural energy power generation facility 100 during the charging operation of the secondary battery type fuel cell system 200 (when the output of the natural energy power generation facility 100 is an AC output). Is supplied to the fuel cell unit 2 and the remaining output of the natural energy power generation facility 100 is converted into an AC output having a frequency suitable for the power system, and then output to the power system.

  In FIG. 1, in order to prevent the drawing from being complicated, illustration of a control line for transmitting a control signal between the system controller 13 and each part of the secondary battery type fuel cell system 200 is omitted. . Moreover, you may provide a temperature sensor etc. around the hydrogen generation member 1 and the fuel cell part 2 as needed. Further, instead of the pump 8, other circulators such as a compressor, a fan, and a blower may be used.

As the hydrogen generating member 1, for example, a metal is used as a base material, and a metal or metal oxide is added to the surface thereof. Hydrogen is generated by an oxidation reaction with water vapor, and can be regenerated by a reduction reaction with hydrogen. Can be used. Examples of the base metal include Ni, Fe, Pd, V, Mg, and alloys based on these, and Fe is particularly preferable because it is inexpensive and easy to process. Examples of the added metal include Al, Rh, Pd, Cr, Ni, Cu, Co, V, and Mo. Examples of the added metal oxide include SiO ₂ and TiO ₂ . However, the metal used as a base material and the added metal are not the same material. In the present embodiment, a hydrogen generation member mainly composed of Fe is used as the hydrogen generation member 1.

The hydrogen generating member mainly composed of Fe can generate hydrogen by consuming water vapor by an oxidation reaction represented by the following formula (1).
4H ₂ O + 3Fe → 4H ₂ + Fe ₃ O ₄ (1)

When the oxidation reaction of iron shown in the above formula (1) proceeds, the change from iron to iron oxide proceeds and the remaining amount of iron decreases, but the reverse reaction of the above formula (1), that is, the following (2 The hydrogen generating member 1 can be regenerated by the reduction reaction shown in the formula. The iron oxidation reaction shown in the above formula (1) and the reduction reaction in the following formula (2) can also be performed at a low temperature of less than 600 ° C.
4H ₂ + Fe ₃ O ₄ → 3Fe + 4H ₂ O (2)

  In the hydrogen generating member 1, it is desirable to increase the surface area per unit volume in order to increase the reactivity. As a measure for increasing the surface area per unit volume of the hydrogen generating member 1, for example, the main body of the hydrogen generating member 1 may be made into fine particles, and the fine particles may be molded. Examples of the fine particles include a method of crushing particles by crushing using a ball mill or the like. Further, the surface area of the fine particles may be further increased by generating cracks in the fine particles by a mechanical method or the like, and the surface area of the fine particles is further increased by roughening the surface of the fine particles by acid treatment, alkali treatment, blasting, etc. It may be increased.

  The hydrogen generating member 1 may have, for example, a form in which fine particles are formed into pellet-like particles and a large number of these particles are filled in the space, and the fine particles are solidified leaving a gap through which gas passes. There may be.

  As shown in FIG. 1, the fuel cell unit 2 has an MEA structure (membrane / electrode assembly) in which a fuel electrode 2B and an air electrode 2C as an oxidant electrode are bonded to both surfaces of an electrolyte membrane 2A. Although FIG. 1 illustrates a structure in which only one MEA is provided, a plurality of MEAs may be provided, or a plurality of MEAs may be stacked.

  As a material of the electrolyte membrane 2A, for example, a solid oxide electrolyte using yttria-stabilized zirconia (YSZ) can be used. For example, Nafion (trademark of DuPont), a cationic conductive polymer, an anion conductive polymer Solid polymer electrolytes such as, but not limited to, those that pass hydrogen ions, those that pass oxygen ions, and those that pass hydroxide ions can be used as fuel cell electrolytes. Any material that satisfies the characteristics is acceptable. In the present embodiment, an electrolyte that passes oxygen ions or hydroxide ions, for example, a solid oxide electrolyte using yttria-stabilized zirconia (YSZ) is used as the electrolyte membrane 2A.

In the case of a solid oxide electrolyte, the electrolyte membrane 2A can be formed using an electrochemical vapor deposition method (CVD-EVD method; Chemical Vapor Deposition _- Electrochemical Vapor Deposition) or the like. If there is, it can be formed using a coating method or the like.

  Each of the fuel electrode 2B and the air electrode 2C can be configured by, for example, a catalyst layer in contact with the electrolyte membrane 2A and a diffusion electrode laminated on the catalyst layer. As the catalyst layer, for example, platinum black or a platinum alloy supported on carbon black can be used. Further, as a material for the diffusion electrode of the fuel electrode 2B, for example, carbon paper, Ni—Fe cermet, Ni—YSZ cermet, or the like can be used. Moreover, as a material of the diffusion electrode of the air electrode 2C, for example, carbon paper, La—Mn—O-based compound, La—Co—Ce-based compound, or the like can be used. Each of the fuel electrode 2B and the air electrode 2C can be formed by using, for example, vapor deposition.

In the fuel cell unit 2, the reaction of the following formula (3) occurs in the fuel electrode 2 </ b> B during power generation of the secondary battery type fuel cell system 200.
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (3)

The electrons generated by the reaction of the above formula (3) reach the air electrode 2C through the power generation charging control unit 12, and the reaction of the following formula (4) occurs in the air electrode 2C.
(1/2) O ₂ + 2e ⁻ → O ²⁻ (4)

And the oxygen ion produced | generated by reaction of said (4) Formula reaches | attains the fuel electrode 2B through electrolyte membrane 2A. By repeating the above series of reactions, the fuel cell unit 2 performs a power generation operation. Further, as can be seen from the above equation (3), during the power generation operation of the secondary battery type fuel cell system 200, H ₂ is consumed and H ₂ O is generated on the fuel electrode 2B side.

From the above formulas (3) and (4), the reaction in the fuel cell unit 2 during the power generation operation of the secondary battery type fuel cell system 200 is as shown in the following formula (5).
H ₂ + (1/2) O ₂ → H ₂ O (5)

On the other hand, the hydrogen generating member 1 consumes H ₂ O generated on the fuel electrode 2B side of the fuel cell unit 2 during power generation of the secondary battery type fuel cell system 200 by the oxidation reaction shown in the above formula (1). To produce H ₂ .

  When the oxidation reaction of iron shown in the above formula (1) proceeds, the change from iron to iron oxide proceeds and the remaining amount of iron decreases, but the hydrogen generating member is reduced by the reduction reaction shown in the above formula (2). 1 can be regenerated, and the secondary battery type fuel cell system 200 can be charged.

In the fuel cell unit 2, when the secondary battery type fuel cell system 200 is charged, an electrolysis reaction shown in the following formula (6), which is a reverse reaction of the formula (5), occurs, and H ₂ on the fuel electrode 2B side O is consumed and H ₂ is generated. In the hydrogen generating member 1, the reduction reaction shown in the above equation (2) occurs, and H ₂ generated on the fuel electrode 2B side of the fuel cell unit ₂ is consumed and H ₂ O is consumed. Is generated.
H ₂ O → H ₂ + (1/2) O ₂ (6)

  Next, the operation of the valve 9 will be described with reference to FIGS. In FIGS. 3 and 4, the black arrow indicates the hydrogen flow, the white arrow indicates the water vapor flow, and the thicker the black arrow and the white arrow, the greater the thickness. This indicates that the gas concentration is high.

  The system controller 13 normally opens the valve 9 fully. Thereby, gas circulates between the hydrogen generating member 1 and the fuel cell unit 2.

  Further, as shown in FIG. 2, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the system controller 13 temporarily closes the valve 9. That is, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the system controller 13 switches the valve 9 from the fully open state to the fully closed state, and then the operation of the secondary battery type fuel cell system 200. Is switched from the charging operation to the power generation operation, or the charging operation of the secondary battery type fuel cell system 200 is continued for a certain time (T1 in FIG. 2), the valve 9 is switched from the fully closed state to the fully open state.

  When the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, while the valve 9 is temporarily fully closed, from the viewpoint of suppressing the pressure increase in the pipe 7, the pump 8 It is desirable to stop the operation or to operate the pump 8 at a lower output than usual.

  Further, in the present embodiment, the above-mentioned fixed time is fixed at T1 in FIG. 2, but the above-mentioned fixed time is determined according to, for example, surplus power of the natural energy power generation facility 100, the water vapor concentration in the fuel cell unit 2, and the like. May be changed. For example, when the sensor for detecting the water vapor concentration in the fuel cell unit 2 is provided and the water vapor concentration in the fuel cell unit 2 becomes the same as the water vapor concentration of the gas generated by the equilibrium reaction of the hydrogen generating member, the above constant Depending on the surplus power of the natural energy power generation facility 100, the time taken to end the time, or the time taken for the water vapor concentration in the fuel cell unit 2 to be the same as the water vapor concentration of the gas generated by the equilibrium reaction of the hydrogen generating member, What is necessary is just to determine the completion | finish time of said fixed time according to the memory content and the value of the surplus electric power of the natural energy power generation equipment 100 memorize | stored by the system controller 13.

  Further, in the present embodiment, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the valve 9 is fully closed, but the output tendency of the natural energy power generation facility 100 is calculated and predicted. The valve 9 may be fully closed in advance immediately before surplus power is generated, that is, immediately before the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation.

  When the secondary battery type fuel cell system 200 is performing a power generation operation, the water vapor concentration is high on the gas outflow side of the fuel cell unit 2 by the reaction of the above formula (5) (see FIG. 3). When the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the valve 9 is fully closed, and the water vapor concentration existing on the gas outflow side of the fuel cell unit 2 is reduced. A high gas is confined upstream of the valve 9 (see FIG. 4), and a gas having a high water vapor concentration is quickly supplied to the fuel cell unit 2 that has started electrolysis. Thereby, the responsiveness of the secondary battery type fuel cell system 200 immediately after switching from the power generation operation to the charging operation is improved. That is, in this embodiment, even after the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, water vapor is sufficiently supplied to the fuel cell unit 2, so that the charging power (= fuel cell) Responsiveness to surplus power of the power consumed by the unit 2 by electrolysis is good, and the secondary battery type fuel cell system 200 can sufficiently charge the surplus power. Further, in this embodiment, immediately after the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the energy necessary for moving a certain amount of water vapor to the fuel cell unit 2 is caused by the valve 9. The energy efficiency of the secondary battery type fuel cell system 200 is also improved because it may be less than in the fully open state.

  Further, while the valve 9 is temporarily fully closed, for example, the pump 8 is operated at a high output, or the temperature of the fuel generating member 1 is increased, for example, so that the fuel generating member 1 is changed to the fuel cell unit 2. It is also possible to increase the amount of water vapor supplied to.

  Unlike the present embodiment, when the valve 9 is always fully opened, the steam from the hydrogen generating member 1 to the fuel cell unit 2 immediately after the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation. Is not sufficiently supplied, the responsiveness to the surplus power of the charging power (= the power consumed by the fuel cell unit 2 by electrolysis) is poor (see the thick dotted line in FIG. 2), and the secondary battery type fuel cell system 200 is surplus. The power cannot be charged sufficiently.

  Next, another operation of the valve 9 will be described with reference to FIG.

  In the operation example of the valve 9 shown in FIG. 5, the system controller 13 repeats the fully open state and the fully closed state of the normal valve 9 at a constant cycle. Thus, a gas having a high water vapor concentration can be retained in the fuel cell unit 2 for a short time during the power generation operation of the secondary battery type fuel cell system 200.

  Further, as shown in FIG. 5, the system controller 13 temporarily closes the valve 9 when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation. That is, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the system controller 13 stops the switching of the valve 9 from the fully closed state to the fully open state, and then the secondary battery type fuel cell. When the operation of the system 200 is switched from the charging operation to the power generation operation or the charging operation of the secondary battery type fuel cell system 200 is continued for a certain time (T1 in FIG. 2), the valve 9 is changed from the fully closed state to the fully opened state. The stop of switching is cancelled | released and the operation | movement which repeats the fully open state and the fully closed state of the valve 9 with a fixed period is restarted.

  An example of the operation of the valve 9 shown in FIG. 5 is that gas having a high water vapor concentration stays in the fuel cell unit 2 for a short time during the power generation operation of the secondary battery type fuel cell system 200. In addition to the effect of the operation example of the valve 9 shown, it is possible to cope with unexpected and unexpected generation of surplus power.

  Next, another operation of the valve 9 will be described with reference to FIG.

  The operation example of the valve 9 shown in FIG. 6 is basically the same operation as the operation example of the valve 9 shown in FIG. 2, but the operation time of the secondary battery type fuel cell system 200 is short and the power generation operation is small. The time period during which the charging operation with small charging power is repeated is different in that the valve 9 is fully closed. As a result, during the period in which the secondary battery type fuel cell system 200 repeats the power generation operation with a small amount of generated power and the charging operation with a short period of time with a small amount of charged power, the fuel cell unit 2 can remove the water vapor generated by the power generation reaction. It is used for the electrolysis reaction immediately after that, and the hydrogen generated by the electrolysis reaction is repeatedly used for the power generation reaction immediately after that, and gas supply from the fuel generating member 1 is not required. Therefore, the operation of the pump 8 can be stopped during a period in which the power generation operation of the secondary battery type fuel cell system 200 is repeated for a short time and the power generation operation of the small power generation is repeated for a short time. The energy efficiency of the battery type fuel cell system 200 can be improved.

  Next, another operation of the valve 9 will be described with reference to FIG.

  In the operation example of the valve 9 shown in FIG. 7, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the opening time of the valve 9 is temporarily reduced every time. The opening degree of the valve 9 is changed. By changing the opening degree of the valve 9, the amount of gas having a high water vapor concentration staying in the fuel cell unit 2 can be adjusted. Since the valve 9 is not fully closed, the pressure in the pipe 7 does not rise abruptly, and deterioration of the secondary battery type fuel cell system 200 can be prevented.

  In the operation example of the valve 9 shown in FIG. 7, for example, the secondary battery type fuel cell system 200 according to the change rate of the generated power immediately before the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation. When the operation is switched from the power generation operation to the charging operation, the opening degree of the valve 9 to be temporarily reduced can be determined. In addition, unlike the operation example of the valve 9 shown in FIG. 7, for example, a sensor for detecting the water vapor concentration in the fuel cell unit 2 is provided, and the fuel is reduced within the time when the opening of the valve 9 is temporarily reduced. You may change the opening degree of the valve | bulb 9 according to the water vapor | steam density | concentration change in the battery part 2. FIG.

Second Embodiment
FIG. 8 shows a schematic configuration of a power feeding system according to the second embodiment of the present invention. The power feeding system according to the present embodiment includes a natural energy power generation facility 100 and a secondary battery type fuel cell system 201.

  The secondary battery type fuel cell system 201 removes the valve 9 from the secondary battery type fuel cell system 200 included in the power supply system according to the first embodiment, and between the gas outflow side and the gas inflow side of the fuel cell unit 2. In this configuration, a bypass pipe 14 for circulating gas without passing through the hydrogen generating member 1 and a valve 15 arranged on the bypass pipe 14 are added.

  When the valve 15 is opened, the bypass pipe 11 is opened, and the gas flowing out from the gas outflow side of the fuel cell unit 2 can be supplied to the gas inflow side of the fuel cell unit 2 without passing through the hydrogen generating member 1. .

  In the present embodiment, the flow resistance of the bypass pipe 11 is designed to be sufficiently smaller than the flow resistance on the hydrogen generating member 1 side when the valve 15 is fully opened. The pump 8 is disposed on the pipe 7 between the gas outflow side of the fuel cell unit 2 and the gas inflow side of the bypass pipe 14. Thereby, the flow path through which the gas flows can be switched between the bypass pipe 11 side and the hydrogen generating member 1 side only by switching the valve 15 to open or close.

  Unlike the present embodiment, the pump 8 may be disposed on the pipe 7 between the gas outflow side of the bypass pipe 14 and the gas inflow side of the fuel cell unit 2.

  Next, the operation of the valve 15 will be described with reference to FIG.

  The system controller 13 normally closes the valve 15. Thereby, gas circulates between the hydrogen generating member 1 and the fuel cell unit 2.

  In addition, as shown in FIG. 9, the system controller 13 temporarily opens the valve 15 when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation. That is, when the operation of the secondary battery type fuel cell system 200 is switched from the power generation operation to the charging operation, the system controller 13 switches the valve 9 from the fully closed state to the fully open state, and then the operation of the secondary battery type fuel cell system 200. When the charging operation is switched from the charging operation to the power generation operation or the charging operation of the secondary battery type fuel cell system 200 is continued for a certain time (T1 in FIG. 9), the valve 15 is switched from the fully open state to the fully closed state.

  By implementing the operation example of the valve 15 shown in FIG. 9, it is possible to obtain the same effect as the operation example of the valve 9 shown in FIG. 2 in the first embodiment.

<Third Embodiment>
FIG. 10 shows a schematic configuration of a power feeding system according to the third embodiment of the present invention. The power supply system according to the present embodiment includes a natural energy power generation facility 100 and a secondary battery type fuel cell system 202.

  In the secondary battery type fuel cell system 202, the valve 15 is removed from the secondary battery type fuel cell system 201 included in the power supply system according to the second embodiment, and three-way connection is made between the pipe 7 and the gas inflow side of the bypass pipe 14. In this configuration, a valve 16 is added.

  The communication between the pump 8 side of the pipe 7 and the gas inflow side of the bypass pipe 14 and the communication between the pump 8 side of the pipe 7 and the hydrogen generating member 1 side can be switched by the three-way valve 16. Therefore, by implementing the operation example of the three-way valve 16 shown in FIG. 11, the same effects as those of the second embodiment can be obtained.

<Fourth embodiment>
The power feeding system according to the fourth embodiment of the present invention is the same as that of the first embodiment except for the peripheral portion of the fuel cell unit 2 which is different from the first embodiment. FIG. 12 shows a peripheral portion of the fuel cell unit 2 in the power supply system according to the present embodiment.

  The power supply system according to the present embodiment includes a plurality of fuel cell units 2. The valve 9 is disposed on the pipe 7 and downstream of the location where the gas outflow sides of the plurality of fuel cell units 2 are combined into one flow path. The power supply system according to the present embodiment achieves the same effects as those of the first embodiment by making the operation of the valve 9 similar to each operation example of the valve 9 described in the first embodiment.

  As shown in FIG. 13, the power supply system according to the present embodiment includes a plurality of valves 9, each valve 9 is on a pipe 7, and the gas outflow sides of the plurality of fuel cell units 2 are provided as one flow path. You may make it arrange | position at the upstream of a gathered location.

<Fifth Embodiment>
FIG. 14 shows a schematic configuration of a power feeding system according to the fifth embodiment of the present invention. The power supply system according to the present embodiment includes a natural energy power generation facility 100 and a secondary battery type fuel cell system 203.

  In the secondary battery type fuel cell system 203, the electrolyzer 17 is added to the secondary battery type fuel cell system 200 included in the power supply system according to the first embodiment, and the power generation charging is performed during the charging operation of the secondary battery type fuel cell system. The control unit 12 supplies power to the electrolyzer 17 instead of the fuel cell unit 2. The electrolyzer 17 is disposed between the gas outflow side of the fuel cell unit 2 and the valve 9. The power supply system according to the present embodiment achieves the same effects as those of the first embodiment by making the operation of the valve 9 similar to each operation example of the valve 9 described in the first embodiment.

<Sixth Embodiment>
FIG. 15 shows a schematic configuration of a power feeding system according to the sixth embodiment of the present invention. The power supply system according to the present embodiment includes a natural energy power generation facility 100 and a secondary battery type fuel cell system 204.

  In the secondary battery type fuel cell system 204, the electrolyzer 17 is added to the secondary battery type fuel cell system 201 included in the power supply system according to the second embodiment, and the power generation charging is performed during the charging operation of the secondary battery type fuel cell system. The control unit 12 supplies power to the electrolyzer 17 instead of the fuel cell unit 2. The electrolyzer 17 is disposed between the gas outflow side of the bypass pipe 14 and the gas inflow side of the fuel cell unit 2. The power supply system according to the present embodiment achieves the same effects as those of the second embodiment by making the operation of the valve 15 the same as the operation example of the valve 15 described in the second embodiment.

  The electrolyzer 17 may be disposed between the gas outflow side of the fuel cell unit 2 and the gas inflow side of the bypass pipe 14.

<Others>
In each of the embodiments described above, a solid oxide electrolyte is used as the electrolyte membrane 2A of the fuel cell unit 2, and water is generated on the fuel electrode 2B side during power generation. According to this configuration, water is generated on the side where the hydrogen generating member 1 is provided, which is advantageous for simplification and miniaturization of the apparatus. On the other hand, as a fuel cell disclosed in Japanese Patent Application Laid-Open No. 2009-99491, a solid polymer electrolyte that allows hydrogen ions to pass through may be used as the electrolyte membrane 2A of the fuel cell unit 2. However, in this case, since water is generated on the air electrode 2C side that is the oxidant electrode of the fuel cell unit 2 during power generation, the water is sent to the gas outflow side of the fuel cell unit 2. A road may be provided.

DESCRIPTION OF SYMBOLS 1 Hydrogen generating member 2 Fuel cell part 2A Electrolyte membrane 2B Fuel electrode 2C Air electrode 3, 4 Heater 5, 6 Container 7, 10, 11 Piping 8 Pump 9, 15 Valve 12 Power generation charge control part 13 System controller 14 Bypass piping 100 Natural Energy power generation equipment 200-204 Secondary battery type fuel cell system

Claims (9)

Hydrogen generation part that can release hydrogen by oxidation reaction and can be regenerated by reduction reaction,
A power generation / electrolysis unit having a power generation function for generating power using hydrogen supplied from the hydrogen generation unit and an electrolysis function for electrolyzing water vapor supplied from the hydrogen generation unit during regeneration of the hydrogen generation unit;
A gas flow path for circulating a gas containing hydrogen and water vapor between the hydrogen generation unit and the power generation / electrolysis unit;
A circulation unit for forcibly circulating a gas containing hydrogen and water vapor between the hydrogen generation unit and the power generation / electrolysis unit;
A secondary battery type fuel cell system comprising a gas flow path control unit for controlling the gas flow path,
The gas flow path control unit controls the gas flow path so as to suppress the circulation of gas through the gas flow path when the operation of the system is switched from a power generation operation to a charging operation. Type fuel cell system.   The secondary battery type according to claim 1, wherein the gas flow path control unit includes a valve disposed on the gas flow path and downstream of the gas generation / electrolysis unit on the gas outflow side. Fuel cell system.   The secondary battery type fuel cell system according to claim 2, wherein when the operation of the system is switched from a power generation operation to a charging operation, the opening of the valve is temporarily reduced.   When the operation of the system is switched from the power generation operation to the charging operation, the circulation amount of the gas forcedly circulated by the circulation unit is reduced while the opening of the valve is temporarily reduced. The secondary battery type fuel cell system according to claim 3. The power generation / electrolysis unit includes a fuel cell unit that generates power using hydrogen supplied from the hydrogen generation unit, and electrolysis that electrolyzes water vapor supplied from the hydrogen generation unit during regeneration of the hydrogen generation unit And
The secondary battery type fuel cell system according to any one of claims 1 to 4, wherein the electrolyzer is disposed downstream of a gas outflow side of the fuel cell unit. A bypass gas flow path for circulating a gas containing hydrogen and water vapor without passing through the hydrogen generation unit between the gas outflow side and the gas inflow side of the power generation / electrolysis unit;
The secondary battery type fuel cell system according to claim 1, wherein the gas flow path control unit includes a valve for controlling the bypass gas flow path.   The secondary battery fuel cell system according to claim 6, wherein the valve temporarily opens the bypass gas passage when the operation of the system is switched from the power generation operation to the charging operation.   The circulation section is on the gas flow path, between the gas outflow side of the power generation / electrolysis section and the gas inflow side of the bypass gas flow path, or the gas outflow side of the bypass gas flow path and the The secondary battery type fuel cell system according to claim 6 or 7, wherein the secondary battery type fuel cell system is disposed between a gas inflow side of a power generation / electrolysis section. A secondary battery type fuel cell system according to any one of claims 1 to 8,
A power supply system comprising: a power generation facility that generates power using natural energy and supplies power to the secondary battery type fuel cell system.