JP2012079558A - Secondary-battery type fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary-battery type fuel cell system in which a hydrogen generator can perform reduction continuously and efficiently during charging.SOLUTION: The secondary-battery type fuel cell system comprising a hydrogen generator 1 for generating hydrogen by oxidation reaction with water and capable of regenerating by reduction reaction with hydrogen, and a SOFC 5 having a power generating function and a function of performing water electrolysis, circulates a gas containing hydrogen and water vapor between the hydrogen generator 1 and the SOFC 5. The secondary-battery type fuel cell system comprises a dewatering unit 7 for removing water vapor from a gas transported from the SOFC 5 during charging of the secondary-battery type fuel cell system, and a recycling unit 8 for mixing water vapor, which has been removed by the dewatering unit 7 during charging of the secondary-battery type fuel cell system, with a gas transported from the hydrogen generator 1 for recycling in the SOFC 5.

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.

  In recent years, as multi-functional and high-performance portable electronic devices such as mobile phones, portable information terminals, notebook personal computers, portable audio devices, and portable visual devices have advanced, the capacity of the drive batteries has increased. There is an increasing demand for conversion. Conventionally, lithium batteries and nickel-cadmium batteries have been used as driving batteries for such portable electronic devices, but their capacities are approaching their limits and cannot be expected to increase dramatically. Therefore, fuel cells having high energy density and high capacity are being actively developed in place of lithium batteries and nickel-cadmium batteries.

  Fuel cells take out electric power when water is generated from hydrogen and oxygen, and in principle, the efficiency of electric power energy that can be taken out is high, which not only saves energy, but also produces only water during power generation. Therefore, it is an environmentally friendly power generation method and is expected as a trump card for solving global energy and environmental problems.

  Such fuel cells typically oxidize a solid polymer electrolyte membrane using a solid polymer ion exchange membrane, a solid oxide electrolyte membrane using yttria-stabilized zirconia (YSZ), and the like with an anode (anode). One cell structure is formed by sandwiching the electrode electrode (cathode) from both sides and sandwiching the outside with a pair of separators. In the cell having such a configuration, a fuel gas flow path for supplying a fuel gas (for example, hydrogen gas) to the fuel electrode, and an oxidant gas flow for supplying an oxidant gas (for example, oxygen or air) to the oxidant electrode. A fuel gas and an oxidant gas are respectively supplied to the fuel electrode and the oxidant electrode through these flow paths.

  However, in a fuel cell device to which fuel is supplied from the outside, infrastructure for supplying fuel (for example, hydrogen) is required. Even when methanol, which is relatively easy to obtain, is used as a fuel, there is a problem that it takes years to circulate.

  Therefore, in order to cope with such a problem, for example, a hydrogen production method proposed in Patent Document 1, that is, an oxidation process in which a metal material and water are reacted to oxidize the metal material to generate hydrogen, and A hydrogen production method in which a metal material and hydrogen are reacted to alternately reduce a reduction step of reducing the metal material can be used. Patent Document 2 proposes to remove water from the exhaust gas generated by the reduction reaction in the step of reducing the metal oxide that generates hydrogen by decomposing water with a reducing gas containing hydrocarbons. Has been.

JP 2008-150256 A JP 2004-359536 A (paragraphs 0024 and 0037)

  In a secondary battery type fuel cell system of the type having a hydrogen generation part that generates hydrogen by an oxidation reaction with water and can be regenerated by a reduction reaction with hydrogen, the hydrogen generation part and the hydrogen supplied from the hydrogen generation part A gas containing hydrogen and water vapor between a power generation function that generates electricity using fuel and an electrolysis function that performs electrolysis of water for generating hydrogen to be supplied to the hydrogen generation unit It is possible to circulate the system.

  In such a secondary battery type fuel cell system, the power generation / electrolysis unit consumes hydrogen to generate water vapor during power generation, and the power generation / electrolysis unit consumes water vapor to generate hydrogen during charging. Let In order for the hydrogen generating unit to efficiently reduce during charging, it is necessary to reduce water vapor contained in the gas supplied from the power generation / electrolysis unit to the hydrogen generating unit during charging.

  However, in the secondary battery type fuel cell system having the above configuration, when the battery is simply configured to remove water vapor from the gas supplied from the power generation / electrolysis unit to the hydrogen generation unit as in Patent Document 2 at the time of charging, Hydrogen molecules corresponding to the amount of water vapor removed are removed from the circulation system, and in the worst case, the charging operation cannot be continued.

  In view of the above situation, an object of the present invention is to provide a secondary battery type fuel cell system in which a hydrogen generator can continuously and efficiently perform reduction during charging.

  In order to achieve the above object, a secondary battery type fuel cell system according to the present invention includes a hydrogen generation unit that generates hydrogen by an oxidation reaction with water and can be regenerated by a reduction reaction with hydrogen. A power generation / electrolysis unit having a power generation function for generating electricity using hydrogen supplied as fuel and an electrolysis function for electrolyzing water for generating hydrogen to be supplied to the hydrogen generation unit, the hydrogen generation A secondary battery type fuel cell system in which a gas containing hydrogen and water vapor is circulated between a power generation unit and the power generation / electrolysis unit, wherein the power generation / electrolysis unit is charged when the secondary battery type fuel cell system is charged A dehydration unit that removes water vapor contained in the gas delivered from the battery, and the water vapor removed by the dehydration unit during charging of the secondary battery type fuel cell system is regenerated in the power generation / electrolysis unit. It has a configuration and a reusable portion of the mixed gas fed from the hydrogen generator to use. The power generation / electrolysis section performs, for example, a power generation operation for generating power using hydrogen supplied from the hydrogen generation section as fuel, and electrolysis of water for generating hydrogen supplied to the hydrogen generation section. For example, the fuel cell may be configured to switch between an electrolysis operation to be performed, and for example, a fuel cell that generates power using hydrogen supplied from the hydrogen generator as a fuel, and hydrogen supplied to the hydrogen generator The electrolysis machine which performs electrolysis of the water for producing | generating this may be provided separately.

  According to such a configuration, when the secondary battery type fuel cell system is charged, the dehydration unit lowers the water vapor partial pressure ratio of the mixed gas sent from the power generation / electrolysis unit, so that the hydrogen partial pressure ratio in the hydrogen generation unit is improved. In addition, the efficiency and reaction rate of the reduction reaction in the hydrogen generation section are improved. In addition, when the secondary battery type fuel cell system is charged, the reuse unit mixes the water vapor removed by the dehydration unit with the gas sent from the hydrogen generation unit, so that the water vapor partial pressure ratio in the power generation / electrolysis unit is improved. In addition, the efficiency and reaction rate of the reduction reaction in the hydrogen generation part are improved. Further, since the water vapor removed by the dehydration unit is reused in the reuse unit and is not discharged out of the circulation system, it is possible to guarantee a continuous reduction reaction in the hydrogen generation unit.

  Therefore, the hydrogen generator can continuously and efficiently perform the reduction during charging.

  In addition, a circulation path for circulating a gas containing hydrogen and water vapor between the hydrogen generation section and the power generation / electrolysis section is provided, and gas flows from the power generation / electrolysis section in the circulation path to the hydrogen generation section. The dehydrating unit may be provided on the route toward, and the recycling unit may be provided on a route from the hydrogen generation unit to the power generation / electrolysis unit in the circulation path.

  A first bypass path provided in parallel with the dehydrating unit; and a second bypass path provided in parallel with the reuse unit, wherein the first bypass path and the second battery type fuel cell system when generating power The gas may flow through the second bypass path, and the gas may not flow through the first bypass path and the second bypass path when the secondary battery type fuel cell system is charged.

  As a specific configuration example of the dehydration unit and the reuse unit, the dehydration unit removes water vapor contained in the gas sent from the power generation / electrolysis unit by a cooling trap, and the reuse unit However, after the water obtained by the cooling trap of the dehydration unit is heated and returned to water vapor, the structure is mixed with the gas delivered from the hydrogen generation unit, and the dehydration unit is configured to generate the power The water vapor contained in the gas sent from the electrolysis unit is removed, and the recycle unit uses the gas sent from the hydrogen generation unit to obtain the water vapor obtained when the dehydrating agent containing water is regenerated. The structure to mix is mentioned.

  According to the present invention, it is possible to realize a secondary battery type fuel cell system in which the hydrogen generator can continuously and efficiently perform reduction during charging.

It is a mimetic diagram showing a schematic structure of a fuel cell system concerning one embodiment of the present invention. It is a schematic diagram which shows schematic structure of a solid oxide fuel cell (SOFC). It is a figure which shows the relationship of the energy of iron and iron oxide. It is a figure explaining the water vapor partial pressure ratio in a hydrogen generator. It is a figure explaining operation | movement at the time of charge of the secondary battery type fuel cell system which simplified FIG. 1 and concerns on one Embodiment of this invention. It is a schematic diagram which shows schematic structure of the fuel cell system which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments described later.

<Configuration of secondary battery type fuel cell system>
FIG. 1 is a diagram showing an overall configuration of a secondary battery type fuel cell system according to an embodiment of the present invention. A secondary battery type fuel cell system according to an embodiment of the present invention shown in FIG. 1 includes a hydrogen generator 1 in which an iron fine particle compact is accommodated. Furthermore, the secondary battery type fuel cell system according to an embodiment of the present invention shown in FIG. 1 includes a heater 2 that heats the hydrogen generator 1, a temperature sensor 3 that detects the temperature of the hydrogen generator 1, and hydrogen generation. And a remaining amount sensor 4 for detecting the remaining iron amount of the container 1. As the remaining amount sensor 4, for example, a sensor that detects the remaining amount of iron in the hydrogen generator 1 from the change in the weight of the hydrogen generator 1 using the weight difference between iron and iron oxide can be used.

  The secondary battery type fuel cell system according to an embodiment of the present invention shown in FIG. 1 also includes a solid oxide fuel cell (SOFC) 5 that is one of fuel cells that generate water using hydrogen as fuel and generate water. ing. The hydrogen generator 1 is connected to the SOFC 5 by a gas circulation path through which gas can be circulated.

  In the circulation path, a circulator 6, a dewatering unit 7, a reuse unit 8, and three-way valves 9 to 12 are provided. The circulator 6 is a blower or a pump and forcibly circulates the gas in the circulation path.

  The dehydrating unit 7 is provided on a path of gas from the SOFC 5 in the circulation path toward the hydrogen generator 1. A first bypass path 13 is provided in parallel with the dehydrating section 7, and a three-way valve 9 is provided at a connection portion between the SOFC 5 side end of the first bypass path 13 and the circulation path, and the hydrogen of the first bypass path 13 is provided. A three-way valve 10 is provided at a connection portion between the generator 1 side end and the circulation path.

  The reuse unit 8 is provided on the path of gas from the hydrogen generator 1 to the SOFC 5 in the circulation path. And the 2nd bypass path 14 is provided in parallel with the reuse part 8, the three-way valve 11 is provided in the connection part of the hydrogen generator 1 side edge part of the 2nd bypass path 14, and the said circulation path, and a 2nd bypass A three-way valve 12 is provided at a connection portion between the SOFC 5 side end of the path 14 and the circulation path.

  The controller 15 controls the entire system, and individually controls the heater 2 and the circulator 6 based on the temperature information output from the temperature sensor 3 and the remaining amount information output from the remaining amount sensor 4. Then, the reaction conditions of the hydrogen generator 1 are set, hydrogen is supplied to the SOFC 5 to cause the SOFC 5 to perform a power generation operation, and the motor 16 as a load is driven.

  Further, the controller 15 operates the SOFC 5 as an electrolyzer when a regenerative electric power of the motor 16 is generated or when electric power from an external power source (not shown) is supplied to the external power input terminal 17 to generate a hydrogen generator. 1 is played to charge the system.

  Furthermore, the controller 15 also controls the three-way valves 9-12.

  The lithium ion secondary battery 18 connected to the controller 15 supplies electric power for operating the heater 2 and the like at the start-up, and an external power source (not shown) is supplied to the power generation or external power input terminal 17 of the SOFC 5. It can be recharged with electric power from

<Configuration and operation of SOFC>
As shown in FIG. 2, the SOFC 5 has a three-layer structure in which a solid electrolyte 19 that permeates O ²⁻ is sandwiched and an oxidant electrode 20 and a fuel electrode 21 are formed on both sides. In the SOFC 5, the following reaction (1) occurs in the fuel electrode 21 during the power generation operation.
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (1)

Electrons generated by the reaction of the above formula (1) pass through the motor 16 as a load and reach the oxidant electrode 20, and the reaction of the following formula (2) occurs at the oxidant electrode 20.
1 / 2O ₂ + 2e ⁻ → O ²⁻ (2)

The oxygen ions generated by the reaction of the above formula (2) reach the fuel electrode 21 through the solid electrolyte 19. By repeating the above series of reactions, the SOFC 5 performs a power generation operation. Further, as can be seen from the above equation (1), during the power generation operation, H ₂ is consumed and H ₂ O is generated on the fuel electrode 21 side.

On the other hand, when the SOFC 5 operates as an electrolyzer, the reverse reactions of the above formulas (1) and (2) occur, and H ₂ O is consumed and H ₂ is generated on the fuel electrode 21 side.

  Gas (hydrogen gas, water vapor gas) consumed or generated on the fuel electrode 21 side as described above circulates between the fuel electrode 21 side of the SOFC 5 and the hydrogen generator 1.

<Reaction in hydrogen generator>
Since the hydrogen generator 1 contains an iron fine particle compact, hydrogen can be generated by an oxidation reaction represented by the following formula (3).
3Fe + 4H ₂ O → Fe ₃ O ₄ + 4H ₂ (3)

  When the oxidation reaction of iron shown in the above formula (3) proceeds, the change from iron to iron oxide proceeds and the remaining amount of iron decreases, but by the reverse reaction (reduction reaction) of the above formula (3), The hydrogen generator 1 can be regenerated and the system can be charged.

Here, the energy relationship between iron (Fe) and iron oxide (Fe ₃ O ₄ ) is shown in FIG. Since iron (Fe) is the energy higher than that of iron oxide _(Fe 3 _{O 4),} the reaction iron (Fe) is changed to iron oxide _(Fe 3 _{O 4)} (oxidation) is an exothermic reaction which releases heat to the outside Thus, the reaction (reduction reaction) in which iron oxide (Fe ₃ O ₄ ) changes to iron (Fe) becomes an endothermic reaction.

Further, in order for the reaction to occur, the molecule needs to have an energy higher than the activation energy Ea, but as can be seen from FIG. 3, the activation energy Ea (Fe → Fe ₃ O ₄ ) of the oxidation reaction The activation energy Ea (Fe ₃ O ₄ → Fe) of the reverse reduction reaction is larger. That is, the iron oxide reduction reaction is less likely to react than the iron oxidation reaction.

The reaction rate constant k indicating the ease of reaction can be expressed by the following equation (4) using the gas constant R, the absolute temperature T, the frequency factor A, and the activation energy Ea. The reaction rate is given by the product of the reaction rate constant k and the concentration. As is well known, when a catalyst is used, the activation energy Ea can be lowered.
k = Aexp (−Ea / RT) (4)

  As can be seen from the above equation (4), when the temperature is raised, the reaction rate k increases exponentially. In practice, in order for the iron oxidation reaction with water vapor gas and the reduction reaction of iron oxide with hydrogen gas to occur, with the currently obtained catalyst, the oxidation reaction of iron is about 80 ° C. or higher and the activation energy is higher. It is necessary to bring the temperature to about 300 ° C. or higher in the iron reduction reaction.

When the activation energy Ea of the reduction reaction is reduced by improving the catalyst in the future, the reduction reaction can be performed under the condition satisfying the following expression (5). However, 200 [kJ] in the following formula (5) is the lowest activation energy of reduction using the currently obtained catalyst, and 550 [K] in the following formula (5) is currently obtained. This is the lowest temperature at which a reduction reaction is possible using the catalyst.
T> (550/200) Ea (5)

<Water vapor partial pressure ratio in the hydrogen generator>
FIG. 4 is a diagram for explaining the steam partial pressure ratio in the hydrogen generator 1. When there is a mixed gas of hydrogen gas and water vapor gas in the hydrogen generator 1 in a state where iron (Fe) and iron oxide (Fe ₃ O ₄ ) are mixed in the hydrogen generator 1, the reaction of the oxidation reaction of iron It stabilizes in an equilibrium state where the rate and the rate of reduction of iron oxide coincide. The curve shown in FIG. 4 shows this equilibrium state. Therefore, the water vapor partial pressure ratio in the equilibrium state becomes higher as the temperature becomes higher. For example, when a mixed gas having a water vapor partial pressure ratio of 10% is introduced into the hydrogen generator 1 under a temperature condition of 300 ° C., the water vapor partial pressure ratio in an equilibrium state is 4% (<10%). The oxidation reaction becomes dominant and finally stabilizes at a water vapor partial pressure ratio of 4%, and the oxidation reaction of iron apparently stops. On the other hand, when a mixed gas having a water vapor partial pressure ratio of 4% is introduced into the hydrogen generator 1 under a temperature condition of 400 ° C., the water vapor partial pressure ratio in the equilibrium state is 10% (> 4%). The reduction reaction of the produced iron oxide becomes dominant and finally stabilizes at a water vapor partial pressure ratio of 10%, and the reduction reaction of iron oxide apparently stops.

<Operation of the secondary battery type fuel cell system>
Next, the operation of the secondary battery type fuel cell system according to one embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. 1 and FIG. In addition, FIG. 5 is a figure explaining the operation | movement at the time of charge of the secondary battery type fuel cell system which simplifies FIG. 1 and which concerns on one Embodiment of this invention.

  When generating electricity by generating hydrogen in the hydrogen generator 1, the controller 15 heats the hydrogen generator 1 with the heater 2 (here, heated to 400 ° C.) and activates the circulator 6 to circulate the gas. Further, under the control of the controller 15, the three-way valve 9 brings the SOFC 5 and the first bypass path 13 into communication, the three-way valve 10 brings the first bypass path 13 and the circulator 6 into communication, and the three-way valve 11 generates hydrogen. The vessel 1 and the second bypass path 14 are in communication with each other, and the three-way valve 12 sets the second bypass path 14 and SOFC 5 in communication. The SOFC 5 generates power while consuming hydrogen gas in the circulation path and generating water vapor gas. Here, the steam generated in the SOFC 5 becomes dominant when the partial pressure ratio becomes higher than 10% of the equilibrium steam partial pressure ratio at 400 ° C., and the steam gas is converted into hydrogen gas in the hydrogen generator 1. Instead, it attempts to return to a state where the water vapor partial pressure ratio is 10% and the hydrogen partial pressure ratio is 90%. Power generation is continued in a cycle in which this hydrogen gas is consumed again by the SOFC 5 and steam gas is generated.

  On the other hand, when the hydrogen generator 1 is regenerated and the system is charged, the controller 15 heats the hydrogen generator 1 with the heater 2 (here, 400 ° C.) and activates the circulator 6 to circulate the gas. Further, under the control of the controller 15, the three-way valve 9 brings the SOFC 5 and the dehydration unit 7 into communication, the three-way valve 10 brings the dehydration unit 7 and the circulator 6 into communication, and the three-way valve 11 reconnects with the hydrogen generator 1. The utilization part 8 is brought into communication, and the three-way valve 12 brings the reuse part 8 and SOFC 5 into communication. Then, the SOFC 5 is operated as an electrolyzer. In this case, the reverse reaction of the above formula (1) occurs in SOFC5, and SOFC5 consumes the water vapor gas in the circulation path and generates hydrogen gas. Here, if the partial pressure ratio of water vapor generated in the hydrogen generator 1 is lower than 10% of the equilibrium water vapor partial pressure ratio at 400 ° C., the reduction reaction of iron oxide becomes dominant, and the hydrogen gas is converted into water vapor in the hydrogen generator 1. It replaces with gas and tries to return to a state where the partial pressure ratio of water vapor is 10% and the partial pressure ratio of hydrogen is 90%. The hydrogen generator 1 is regenerated in a cycle in which the water vapor gas is consumed again by the SOFC 5 and hydrogen gas is generated, and charging of the system is continued.

  In order to improve the efficiency of electrolysis and reaction rate in SOFC5, it is necessary to increase the amount of water vapor supplied to SOFC5. In order to improve the efficiency and reaction rate of the reduction reaction in the hydrogen generator 1, it is necessary to increase the hydrogen partial pressure ratio in the hydrogen generator 1 by supplying hydrogen to the hydrogen generator 1, but the SOFC5 Does not consume all the water vapor gas in the circulation path in the reverse reaction of the above equation (1), so the gas sent from the SOFC 5 is not pure hydrogen gas but water vapor gas that has not reacted with hydrogen gas. (A mixed gas having a hydrogen partial pressure ratio of 95% and a water vapor partial pressure ratio of 5%).

  Therefore, in the secondary battery type fuel cell system according to one embodiment of the present invention shown in FIG. 1, the dehydration unit 7 is mixed from the SOFC 5 by a cooling trap (here, a 0 ° C. cooling trap) when the system is charged. The water vapor partial pressure ratio of the gas is reduced to about 1%. Thereby, the hydrogen partial pressure ratio of the mixed gas supplied to the hydrogen generator 1 is improved to about 99% (see FIG. 5), and the efficiency and reaction rate of the reduction reaction in the hydrogen generator 1 are improved. For cooling in the dehydrating unit 7, for example, a Peltier element controlled by the controller 15 can be used.

  Further, the water trapped by the cooling trap of the dehydration unit 7 is transferred from the dehydration unit 7 to the reuse unit 8, heated in the reuse unit 8, returned to the water vapor gas, and sent from the hydrogen generator 1. Mixed with. Thereby, the water vapor partial pressure ratio of the mixed gas supplied to the SOFC 5 is improved to about 15% (see FIG. 5), and the efficiency and reaction rate of the reduction reaction in the hydrogen generator 1 are improved. Further, since the water trapped by the cooling trap of the dehydration unit 7 is reused in the reuse unit 8 and is not removed from the circulation path, a continuous reduction reaction in the hydrogen generator 1 can be ensured. For the heating in the reuse unit 8, for example, a heater controlled by the controller 15 can be used.

  As described above, in the secondary battery type fuel cell system according to the embodiment of the present invention shown in FIG. 1, the hydrogen generator 1 can continuously and efficiently perform the reduction during charging.

  In this embodiment, one SOFC 5 performs both power generation and water electrolysis. However, the hydrogen generator 1 includes a fuel cell (for example, a SOFC dedicated to power generation) and a water electrolyzer (for example, water electrolysis). A dedicated SOFC) may be connected in parallel on the gas circulation path. Further, the base material (main component) of the hydrogen generator 1 is not limited to iron, but may be any material that can be oxidized with water and reduced with hydrogen (for example, a magnesium alloy).

<Other configuration of the secondary battery type fuel cell system>
FIG. 6 is a diagram showing an overall configuration of a secondary battery type fuel cell system according to another embodiment of the present invention. In FIG. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals. A secondary battery type fuel cell system according to another embodiment of the present invention shown in FIG. 6 includes a secondary battery type fuel cell system according to an embodiment of the present invention shown in FIG. In addition, the specific configurations of the dehydration unit 7 and the reuse unit 8 are also different from the secondary battery type fuel cell system according to the embodiment of the present invention shown in FIG. The circulation transport mechanism 22 circulates and transports a granular dehydrating agent (here, calcium oxide) between the dehydrating unit 7 and the reuse unit 8.

  The operation of the secondary battery type fuel cell system according to another embodiment of the present invention shown in FIG. 6 is to charge the system by regenerating the hydrogen generator 1 when generating power by generating hydrogen in the hydrogen generator 1. The operation is basically the same as the operation of the secondary battery type fuel cell system according to the embodiment of the present invention shown in FIG.

At the time of charging the system,
Water vapor in the mixed gas delivered from the SOFC 5 reacts with calcium oxide as a dehydrating agent to generate calcium hydroxide (see the following formula (6)).
CaO + H ₂ O → Ca (OH) ₂ (6)

  By the reaction of the above formula (6), the water vapor partial pressure ratio of the mixed gas delivered from the SOFC 5 can be reduced. Thereby, the hydrogen partial pressure ratio of the mixed gas supplied to the hydrogen generator 1 is improved, and the efficiency and reaction rate of the reduction reaction in the hydrogen generator 1 are improved.

Further, the calcium hydroxide generated by the reaction of the above formula (6) is transported from the dehydrating unit 7 to the reuse unit 8 by the circulation transport mechanism 22 and heated in the reuse unit 8 to convert the calcium hydroxide into water vapor gas. And the calcium oxide (see the following formula (7)), the water vapor gas is mixed with the gas delivered from the hydrogen generator 1, and the calcium oxide is transferred from the recycling unit 8 to the dehydrating unit 7 by the circulation transport mechanism 22. Transported.
Ca (OH) ₂ → CaO + H ₂ O (7)

  Thereby, the water vapor partial pressure ratio of the mixed gas supplied to the SOFC 5 is improved, and the efficiency and reaction rate of the reduction reaction in the hydrogen generator 1 are improved. Further, since the water removed by the dehydration unit 7 is reused in the reuse unit 8 and is not removed from the circulation path, the continuous reduction reaction in the hydrogen generator 1 can be guaranteed.

  As described above, in the secondary battery type fuel cell system according to another embodiment of the present invention shown in FIG. 6, the hydrogen generator 1 can continuously and efficiently reduce during charging.

  In addition, a dehydrating agent is not limited to calcium oxide, What is necessary is just a reproducible thing.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Heater 3 Temperature sensor 4 Remaining amount sensor 5 Solid oxide fuel cell (SOFC)
DESCRIPTION OF SYMBOLS 6 Circulator 7 Dehydration part 8 Reuse part 9-12 Three-way valve 13 1st bypass path 14 2nd bypass path 15 Controller 16 Motor 17 External power supply input terminal 18 Lithium ion secondary battery 19 Solid electrolyte 20 Oxidant electrode 21 Fuel electrode 22 Circulation transport mechanism

Claims (5)

A hydrogen generating part that generates hydrogen by an oxidation reaction with water and can be regenerated by a reduction reaction with hydrogen;
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 for generating hydrogen supplied to the hydrogen generation unit; Prepared,
A secondary battery type fuel cell system for circulating a gas containing hydrogen and water vapor between the hydrogen generation unit and the power generation / electrolysis unit,
A dehydration unit that removes water vapor contained in the gas sent from the power generation / electrolysis unit when charging the secondary battery type fuel cell system;
A recycle unit that mixes the water vapor removed by the dehydration unit with the gas sent from the hydrogen generation unit to be reused in the power generation / electrolysis unit during charging of the secondary battery type fuel cell system; A secondary battery type fuel cell system comprising: A circulation path for circulating a gas containing hydrogen and water vapor between the hydrogen generation unit and the power generation / electrolysis unit;
The dehydration unit is provided on a path of gas from the power generation / electrolysis unit in the circulation path to the hydrogen generation unit,
2. The secondary battery type fuel cell system according to claim 1, wherein the recycle unit is provided on a path of gas from the hydrogen generation unit to the power generation / electrolysis unit in the circulation path. A first bypass path provided in parallel with the dewatering unit;
A second bypass path provided in parallel with the reuse unit,
Gas flows through the first bypass path and the second bypass path during power generation of the secondary battery type fuel cell system, and when the secondary battery type fuel cell system is charged, the gas flows through the first bypass path and the second bypass path. The secondary battery type fuel cell system according to claim 2, wherein gas does not flow. The dehydration unit removes water vapor contained in the gas sent from the power generation / electrolysis unit by a cooling trap,
The said reuse part heats the water obtained by the cooling trap of the said dehydration part, returns to water vapor | steam, and then mixes with the gas sent from the said hydrogen generation part. The secondary battery type fuel cell system according to any one of the above. The dehydration unit removes water vapor contained in the gas sent from the power generation / electrolysis unit with a dehydrating agent,
The reusable part mixes the water vapor obtained when regenerating the dehydrating agent containing moisture with the gas delivered from the hydrogen generating part. The secondary battery type fuel cell system described.