JP2013218905A - Fuel cell system manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system manufacturing method which can improve durability without sacrificing power generation efficiency.SOLUTION: A manufacturing method for a fuel cell system comprising a fuel generation member and a fuel cell section is provided. The manufacturing method includes: a formation step of forming a space having a fuel electrode of the fuel cell section and the fuel generation member disposed therein and in which at least two gas circulation sections for letting gas circulate between the inside and the outside are formed; a replacement step in which, after the formation step, the gas in the space is replaced with a first gas of the same kind as fuel, a second gas of the same kind as an oxide of the fuel, and a mixed gas of the first and second gases by utilizing a gas passage, and the number of molecules of the gas present in the space is adjusted so that the total pressure of the gas present in the space when the space is at room temperature is smaller than the atmospheric pressure; and a closing step in which, after the replacement step, the gas passage is closed to make the space a close space.

Description

  The present invention relates to a method for manufacturing a fuel cell system including a fuel generating member that generates fuel by a chemical reaction.

  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 flow path for supplying fuel gas (for example, hydrogen gas) to the fuel electrode and an oxidant gas flow path for supplying oxidant gas (for example, oxygen or air) to the oxidant electrode are provided. Power generation is performed by supplying fuel gas and oxidant gas to the fuel electrode and oxidant electrode through the passage.

  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.

International Publication No. 2011/030625 JP 2008-84849 A JP 2010-103045 A

  Patent Document 1 discloses a secondary battery type fuel cell system including a fuel cell unit and a fuel generating member that generates a fuel that is a reducing substance by a chemical reaction and can be regenerated by a reverse reaction of the chemical reaction. ing. In the secondary battery type fuel cell system disclosed in Patent Document 1, the space where the fuel electrode of the fuel cell portion and the fuel generating member are sealed is a closed space, and the fuel gas exists in the closed space. .

  The operating temperature of the fuel cell unit, the temperature required for the chemical reaction to occur in the fuel generating member, and the temperature required for the reverse reaction of the chemical reaction to occur in the fuel generating member are higher than room temperature, respectively. During the power generation operation and charging operation of the fuel cell system, the temperature of the closed space rises compared to when the operation is stopped, and as the temperature rises, the pressure in the closed space increases, The pressure difference with the outside increases.

  Therefore, the member for forming the closed space needs to have a strength that can withstand the pressure difference. However, the electrolyte of the fuel cell part, which is a part of the member for forming the closed space, generates power. It is thinned to improve efficiency, has low strength, and is easily damaged. That is, it is a challenge to improve both power generation efficiency and durability.

  Here, with regard to a method for adjusting the pressure in the fuel cell, for example, in Patent Document 2, the power generation stop method of the fuel cell is a fuel for the purpose of suppressing the pressure difference between the fuel electrode and the oxidant electrode when the fuel cell is stopped. An open air stage for opening the fuel flow path of the battery to the atmosphere is provided. However, when the secondary battery type fuel cell system disclosed in Patent Document 1 is used by circulating the gas existing in the closed space between the fuel electrode of the fuel cell unit and the fuel generating member. The closed space cannot be opened to the atmosphere. In addition, when the secondary battery type fuel cell system disclosed in Patent Document 1 is used by circulating the gas existing in the closed space between the fuel electrode of the fuel cell unit and the fuel generating member, In addition, a pressure difference is generated during the power generation operation and the charging operation, not when the operation is stopped.

  Further, for example, in Patent Document 3, the fuel reformer is sealed at a high pressure for the purpose of preventing the outside air from flowing into the reformer when the temperature drops and preventing the catalyst from being deteriorated by the outside air. I have to. However, when the secondary battery type fuel cell system disclosed in Patent Document 1 is used by circulating the gas existing in the closed space between the fuel electrode of the fuel cell unit and the fuel generating member. Outside air does not flow into the closed space. In addition, when the secondary battery type fuel cell system disclosed in Patent Document 1 is used by circulating the gas existing in the closed space between the fuel electrode of the fuel cell unit and the fuel generating member. When the closed space is sealed with high pressure, the pressure difference between the inside and the outside of the closed space is further increased.

  In view of the above situation, an object of the present invention is to provide a method of manufacturing a fuel cell system capable of improving durability without sacrificing power generation efficiency.

  In order to achieve the above object, a method of manufacturing a fuel cell system according to the present invention includes a fuel generating member that generates fuel by a chemical reaction, an oxidant containing oxygen, and a fuel supplied from the fuel generating member. A fuel cell system manufacturing method comprising a fuel cell unit for generating power, wherein a fuel electrode of the fuel cell unit and the fuel generating member are disposed inside, and gas is circulated between the inside and the outside. Forming a space in which at least two gas circulation portions capable of being formed are formed, and after the formation step, the gas circulation portion is used to convert the gas in the space into a first gas of the same type as the fuel, the fuel Substituting with a second gas of the same kind as the oxide of the above, or a mixed gas of the first gas and the second gas, the total number of molecules of the gas existing in the space is present in the space when the space is at room temperature. Total pressure of gas It is set as the structure (1st structure) provided with the substitution process adjusted to the number which becomes smaller than atmospheric pressure, and the closing process which closes the said gas distribution part and makes the said space closed after the said substitution process. . In addition, room temperature is 25 degreeC, for example, and is a certain temperature suitably selected in the range of about 0 degreeC-40 degreeC specifically, and is also called normal temperature.

  In the fuel cell system obtained by the manufacturing method of the first configuration, the pressure difference between the inside and the outside of the closed space in which the fuel electrode and the fuel generating member of the fuel cell unit are arranged is the operating time of the fuel cell unit. Can be prevented from becoming large. Therefore, durability can be improved without sacrificing power generation efficiency.

  Further, in the manufacturing method of the first configuration, the replacement step includes the step of replacing the gas in the space with a first gas of the same type as the fuel, a second gas of the same type as the oxide of the fuel, or a first gas and the first gas. By substituting with a mixed gas of two gases and adjusting the total pressure of the gas existing in the space to be lower than the atmospheric pressure in a state where the space is at room temperature, the gas existing in the space is reduced. A configuration in which the total number of molecules is adjusted to a number such that the total pressure of the gas existing in the space is smaller than the atmospheric pressure when the space is at room temperature (second configuration) may be employed.

  Further, in the manufacturing method of the first configuration, the replacement step includes the step of replacing the gas in the space with a first gas of the same type as the fuel, a second gas of the same type as the oxide of the fuel, or a first gas and the first gas. The gas existing in the space is replaced with a mixed gas of two gases, and the total pressure of the gas existing in the space is adjusted to atmospheric pressure in a state where the space is higher than room temperature. The total number of molecules may be adjusted to a number such that the total pressure of the gas existing in the space becomes smaller than atmospheric pressure when the space is at room temperature (third configuration).

  Further, in the manufacturing method of any one of the first to third configurations, the fuel is hydrogen, and the closing step is a plurality of different closing methods for each of the gas circulation parts after the replacement step. It is good also as a structure (4th structure) which is the process of closing the said gas distribution | circulation part in multiples using this and making the said space closed.

  The fuel cell system obtained by the manufacturing method according to the present invention has a large pressure difference between the inside and the outside of the closed space in which the fuel electrode of the fuel cell unit and the fuel generating member are disposed when the fuel cell unit operates. Can be suppressed. Therefore, durability can be improved without sacrificing power generation efficiency.

It is a schematic diagram which shows schematic structure of the fuel cell system obtained by the manufacturing method which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the outline | summary of the formation process first half in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the formation process first half in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the latter half of the formation process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the substitution process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the substitution process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the closing process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the closing process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the closing process in 1st Embodiment. It is a schematic diagram which shows the outline | summary of the substitution process in 2nd Embodiment. It is a schematic diagram which shows the outline | summary of the modification of the replacement process in 2nd Embodiment. It is a schematic diagram which shows the outline | summary of the substitution process in 3rd Embodiment. It is a schematic diagram which shows the other schematic structure of the fuel cell system obtained by the manufacturing method which concerns on 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.

<< First Embodiment >>
<Fuel cell system>
FIG. 1 shows a schematic configuration of a fuel cell system obtained by the manufacturing method according to the first embodiment of the present invention. The fuel system shown in FIG. 1 includes a fuel generating member 1, a container 3 that accommodates the fuel generating member 1 and the fuel cell unit 2, a first pipe 4, a first valve 5, and a second pipe 6. The second valve 7 is provided. Moreover, you may provide the heater which adjusts the temperature of the fuel generation member 1 and the fuel cell part 2, the circulator which circulates gas compulsorily, etc. in the container 3 as needed.

  When the first valve 5 and the second valve 7 are closed, the electrolyte membrane 2A of the fuel cell unit 2, the container 3, the first pipe 4, the first valve 5, and the second pipe 6 The second valve 7 forms a closed space in which the fuel electrode 2B of the fuel cell unit 2 and the fuel generating member 1 are disposed.

<Fuel generating member>
As a material of the fuel generating member 1, for example, a material in which a metal is used as a base material, a metal or a metal oxide is added to the surface, and a fuel is generated by a chemical reaction 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, Rd, 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 this embodiment, a fuel generating member mainly composed of Fe is used as the fuel generating member 1.

  In the fuel 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 fuel generating member 1, for example, the main body of the fuel 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.

  Further, Ti, Zr, V, Nb, Cr, Mo, Al, Ga, Mg, Sc, Ni, Cu, Nd, or the like may be added as a catalyst.

<Fuel cell part>
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. 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 satisfying the characteristics may be used. 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 this case, hydrogen can be generated from the fuel generating member 1 by a chemical reaction using water vapor generated on the fuel electrode 2B side during the power generation operation.

  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, and in the case of a solid polymer electrolyte. 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.

<Chemical reaction during operation>
Next, chemical reactions that occur during the operation of the fuel system shown in FIG. 1 will be described.

For example, when the fuel is hydrogen, in the present embodiment, the following reaction (1) occurs in the fuel electrode 2B during the power generation operation.
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (1)

Electrons generated by the reaction of the above formula (1) reach the air electrode 2C from the fuel electrode 2B through an external load (not shown), and the reaction of the following formula (2) occurs in the air electrode 2C. .
1 / 2O ₂ + 2e ⁻ → O ²⁻ (2)

  And the oxygen ion produced | generated by reaction of said (2) Formula reaches | attains the fuel electrode 2B through 2 A of electrolyte membranes. By repeating the above series of reactions, the fuel cell unit 2 performs a power generation operation.

Further, in this embodiment, the fuel generating member 1 consumes water vapor supplied from the fuel cell unit 2 by the Fe oxidation reaction represented by the following formula (3) to generate hydrogen gas, The fuel cell unit 2 is supplied.
4H ₂ O + 3Fe → 4H ₂ + Fe ₃ O ₄ (3)

  The fuel cell system shown in FIG. 1 is a secondary battery type fuel cell system that can perform not only a power generation operation but also a charging operation. During the charging operation, the fuel cell unit 2 is connected to an external power source (not shown) and operates as an electrolyzer, and reverse reactions of the above formulas (1) and (2) occur, and water vapor is generated on the fuel electrode 2B side. Is generated and hydrogen gas is generated, and the fuel generating member 1 increases the remaining amount of iron by advancing the change from iron oxide to iron by the reduction reaction which is the reverse reaction of the above equation (3), that is, the fuel generating member 1 is regenerated, consumes the hydrogen gas supplied from the fuel cell unit 2 to generate water vapor, and supplies the water vapor to the fuel cell unit 2.

<Formation process>
In the formation process at the time of manufacturing the fuel cell system shown in FIG. 1, first, the fuel generating member 1 is provided inside the first package member 3_1 in which the first opening 3A and the second opening 3B are provided. In addition, the fuel cell unit 2 is disposed, and the first package member 3_1 and the electrolyte membrane 2A are hermetically connected using a sealing member 3_3 such as ceramic bond or glass seal, and then the first package member 3_1. And the second package member 3_2 are combined, and the first package member 3_1 and the second package member 3_2 are connected using the sealing member 3_3 (see FIG. 2). A container 3 is constituted by the first package member 3_1, the second package member 3_2, and the sealing member 3_3.

  Unlike the method for forming the container 3 described above, the first package member 3_1, the second package member 3_2, and the electrolyte membrane 2A may be simultaneously connected using the sealing member 3_3 (FIG. 3). reference).

  Further, when the container 3 is formed, a connection terminal may be drawn out of the container 3 from each of the fuel electrode 2B and the air electrode 2C.

  After forming the container 3, as shown in FIG. 4, one end of the first pipe 4 is hermetically connected to the first opening 3 </ b> A provided in the container 3, and the second opening provided in the container 3. One end of the second pipe 6 is hermetically connected to the part 3B. A first valve 5 is disposed on the path of the first pipe 4, and a second valve 7 is disposed on the path of the second pipe 6.

  By opening the first valve 5, the first pipe 4 that is airtightly connected to the first opening 3 </ b> A allows the gas to flow between the inside and the outside of the container 3. Become a distribution department. Similarly, by opening the second valve 7, the second pipe 6 that is airtightly connected to the second opening 3 </ b> B can circulate gas between the inside and the outside of the container 3. 2 gas distribution part.

  The 1st piping 4 and the 2nd piping 6 are comprised with the material which has airtightness, such as ceramic cloth, SUS (stainless steel), glass, resin. In addition, when the pipe itself becomes high temperature, it is preferable that the pipe is made of a heat-resistant material such as ceramic cloth, SUS (stainless steel), or glass. As a method for connecting the container 3 to the first opening 3A and the second opening 3B, a highly airtight joining method such as welding or anodic bonding is preferable. In the case of welding, it is preferable that the thermal expansion coefficient of the material used for the container 3 and the thermal expansion coefficient of the material used for the first pipe 4 and the second pipe 6 are close to each other. Moreover, in the case of anodic bonding, it is preferable that the combination of the material used for the container 3 and the material used for the first pipe 4 and the second pipe 6 is a bondable glass and metal. Examples of the metal material include iron, stainless steel, silicon, copper, aluminum, and alloys thereof. Examples of the glass material include borosilicate glass and soda lime glass.

<Replacement process>
In the replacement process at the time of manufacturing the fuel cell system shown in FIG. 1, the first pipe 4 and the pipe 9 on the hydrogen supply device 8 side are hermetically sealed using a joint 11 such as Swagelok (registered trademark) as shown in FIG. And the second pipe 6 and the pipe 13 on the exhaust device 14 side are hermetically connected using a joint 12 such as a swage lock. A pressure regulator 10 such as a valve or a regulator is arranged on the path of the pipe 9. In the present embodiment, the pipes are connected by a joint, but may be connected by a connection tube or welding.

  Examples of the hydrogen supply device 8 include those capable of supplying high-purity hydrogen such as hydrogen cylinders and hydrogen storage alloys. Examples of the exhaust device 14 include a duct and a gas suction pump.

  Hydrogen is supplied from the hydrogen supply device 8 to a space surrounded by the electrolyte membrane 2A and the container 3 and in which the fuel generating member 1 and the fuel electrode 2B are disposed, and the fuel generating member is surrounded by the electrolyte membrane 2A and the container 3 The exhaust device 14 exhausts the gas inside the space in which 1 and the fuel electrode 2B are disposed. Thereby, the gas in the space surrounded by the electrolyte membrane 2A and the container 3 and in which the fuel generating member 1 and the fuel electrode 2B are disposed is replaced with hydrogen gas.

  At this time, in a state where the space surrounded by the electrolyte membrane 2A and the container 3 and in which the fuel generating member 1 and the fuel electrode 2B are disposed is at room temperature, the supply amount from the hydrogen supply device 8 and the exhaust device 14 The total pressure of the gas existing in the space is made smaller than the atmospheric pressure by adjusting the displacement. Thereby, the total number of molecules of the gas existing in the space becomes a number such that the total pressure of the gas existing in the space becomes smaller than the atmospheric pressure when the space is at room temperature.

  When the gas in the space is sufficiently replaced with hydrogen gas, and the total pressure of the gas existing in the space becomes smaller than the atmospheric pressure, the replacement process is finished. As shown in FIG. 6, a gas concentration detection sensor 15 such as a hydrogen concentration detection sensor or an oxygen concentration detection sensor is provided in the space, and the gas replacement status in the space is grasped based on the detection result of the gas concentration detection sensor 15. You may do it. In the present embodiment, the gas in the space is replaced with the same type of gas as the fuel. However, the gas may be replaced with the same type of gas as the fuel oxide, or may be replaced with a mixed gas of the two types of gas. May be.

<Closed process>
After the replacement process is completed, the first valve 5 and the second valve 7 are closed to close the space, and when the joints 11 and 12 are removed, the fuel cell system shown in FIG. 1 is completed. To do. In the present embodiment, the first gas flow part and the second gas flow part are closed by closing the first valve 5 and the second valve 7, but instead of the valve, for example, FIG. The first gas circulation part and the second gas circulation part may be closed using crimping as shown in FIG. 7, sealing as shown in FIG. In the case of sealing, the shape changing member 16 is fixed in the first pipe 4 and the second pipe 6 in a state where a gap for circulating gas is secured at first, and when the temperature changes to a predetermined temperature or higher. Then, it melts to cause a shape change and closes the first pipe 4 and the second pipe 6 as shown in FIG. Examples of the material of the shape changing member 16 include low melting glass (borate, silicate, germanate, vanadate, phosphate, arsenate, telluride, etc.), low melting point metal, and the like. Among them, a material having a melting point higher than the operating temperature of the fuel cell system (for example, 600 ° C.) can be selected.

  In the above-described embodiment, the first gas circulation part and the second gas circulation part are closed by using a single closing method for each of the first gas circulation part and the second gas circulation part. The first gas circulation part and the second gas circulation part may be closed in multiple ways by using a plurality of different closing methods for the first gas circulation part and the second gas circulation part, respectively. For example, in addition to closing using a valve, crimping, sealing, etc., closing using a heat-resistant sealing material, a heat-resistant inorganic adhesive, a hole-filling member fitted in a pipe, or the like may be performed. An example of multiple closure using crimping and the heat-resistant inorganic adhesive 17 is shown in FIG. When the fuel is hydrogen, multiple closures are particularly useful because the molecular weight is small and the fuel is likely to leak from the closure.

  Here, the gas equation of state PV = nRT (P: pressure in space, V: volume of space, n: number of gas molecules in space, R: gas constant, T: absolute temperature of space) The effect of suppressing the pressure difference between the inside and the outside of the closed space obtained by the manufacturing method described above will be considered.

  Since the number of gas molecules in the closed space does not change as can be seen from the above formula (1) and its reverse reaction and the above formula (4) and its reverse reaction, the absolute temperature of the closed space is required to operate the fuel cell system. When T is increased, the volume V of the closed space is constant, so that the pressure Pin in the closed space increases. Therefore, stress is applied to the electrolyte membrane 2A of the fuel cell portion 2 by the pressure difference ΔP between the pressure Pin in the closed space and the pressure Pout (atmospheric pressure) outside the closed space.

However, in the manufacturing method described above, the total number of molecules of the gas existing in the space is such that the total pressure of the gas existing in the space is smaller than the atmospheric pressure when the space is at room temperature. Therefore, an increase in the pressure Pin in the closed space at the time of temperature rise (during operation of the fuel cell system) is suppressed, the pressure difference ΔP is reduced, and the stress applied to the electrolyte membrane 2A of the fuel cell unit 2 is reduced. Get smaller. Therefore, durability can be improved without sacrificing power generation efficiency.

The pressure difference ΔP varies depending on the absolute temperature T of the closed space. When the total pressure of the gas existing in the space is adjusted in the replacement step so that the pressure Pin in the closed space at a temperature intermediate between the room temperature and the operating temperature of the fuel cell system becomes equal to the atmospheric pressure, the pressure The maximum value of the difference ΔP (the pressure difference ΔP at room temperature or the pressure difference ΔP during operation of the fuel cell system) can be minimized.

<< Second Embodiment >>
The manufacturing method according to the second embodiment of the present invention changes the replacement step as follows in the manufacturing method according to the first embodiment of the present invention.

  In the replacement process at the time of manufacturing the fuel cell system shown in FIG. 1, the container 3 is installed in the heating furnace 18 as shown in FIG. 10, and the first pipe 4 and the pipe 9 on the hydrogen supply device 8 side are swage locked or the like. The second pipe 6 and the exhaust device 14 side pipe 13 are connected airtightly using a joint 12 such as a swage lock. A pressure regulator 10 such as a valve or a regulator is arranged on the path of the pipe 9. In the present embodiment, the pipes are connected by a joint, but may be connected by a connection tube or welding. In the present embodiment, the entire container 3 is installed in the heating furnace 18, but it is sufficient that at least a part of the closed space is in the heating furnace 18. Further, a plurality of containers 3 may be put in one heating furnace 18 and heated at the same time. Further, the second pipe 6 may be opened to the atmosphere without being connected to the exhaust device 14.

  Examples of the hydrogen supply device 8 include those capable of supplying high-purity hydrogen such as hydrogen cylinders and hydrogen storage alloys. Examples of the exhaust device 14 include a duct and a gas suction pump.

  Hydrogen is supplied from the hydrogen supply device 8 to a space surrounded by the electrolyte membrane 2A and the container 3 and in which the fuel generating member 1 and the fuel electrode 2B are disposed, and the fuel generating member is surrounded by the electrolyte membrane 2A and the container 3 The exhaust device 14 exhausts the gas inside the space in which 1 and the fuel electrode 2B are disposed. Thereby, the gas in the space surrounded by the electrolyte membrane 2A and the container 3 and in which the fuel generating member 1 and the fuel electrode 2B are disposed is replaced with hydrogen gas.

  At this time, the temperature in the heating furnace 18 is maintained at a temperature higher than room temperature, more preferably, the temperature in the heating furnace 18 is maintained at a temperature higher than room temperature and lower than the operating temperature of the fuel cell unit 2, and the electrolyte membrane 2A The amount of supply from the hydrogen supply device 8 and the amount of exhaust to the exhaust device 14 in a state where the temperature of the space surrounded by the container 3 and the fuel generating member 1 and the fuel electrode 2B is higher than room temperature And the total pressure of the gas existing in the space is made equal to the atmospheric pressure. Thereby, the total number of molecules of the gas existing in the space becomes a number such that the total pressure of the gas existing in the space becomes smaller than the atmospheric pressure when the space is at room temperature.

  When the gas in the space is sufficiently replaced with hydrogen gas and the total pressure of the gas existing in the space becomes equal to the atmospheric pressure, the replacement process is terminated. As shown in FIG. 11, a gas concentration detection sensor 15 such as a hydrogen concentration detection sensor or an oxygen concentration detection sensor is provided in the space, and the gas replacement status in the space is grasped based on the detection result of the gas concentration detection sensor 15. You may do it. In the present embodiment, the gas in the space is replaced with the same type of gas as the fuel. However, the gas may be replaced with the same type of gas as the fuel oxide, or may be replaced with a mixed gas of the two types of gas. May be.

<< Third Embodiment >>
The manufacturing method according to the third embodiment of the present invention changes the replacement step as follows in the manufacturing method according to the second embodiment of the present invention.

  As shown in FIG. 12, the pressure regulator is not arranged on the path of the pipe 9, and the rest is the same as the replacement process of the manufacturing method according to the second embodiment of the present invention. In addition, the modification in the manufacturing method which concerns on 2nd Embodiment of this invention is applicable also to the manufacturing method which concerns on 3rd Embodiment of this invention.

<< Modification >>
Further, the fuel cell system obtained by the manufacturing method of each embodiment described above has a structure in which the fuel generating member 1 and the fuel cell unit 2 are accommodated in the same container 3, but the fuel generating member as shown in FIG. 1 and the fuel cell apparatus 2 may be stored in separate containers.

  In the fuel cell system obtained by the manufacturing method of each embodiment described above, an electrolyte that conducts oxygen ions is used as the electrolyte membrane 2A, and water is generated on the fuel electrode 2B side during power generation. According to this configuration, since water is generated on the electrode side (fuel electrode 2B side) connected to the fuel generating member 1 by the gas flow path for supplying fuel from the fuel generating member 1 to the fuel cell unit 2, the apparatus This is advantageous for simplification and downsizing. 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 can be used as the electrolyte of the fuel cell unit 2. However, in this case, since water is generated on the air electrode 2C side during power generation, a flow path for propagating this water to the fuel generating member 1 may be provided. The flow path is configured to only propagate water from the air electrode 2C to the fuel generating member 1, and a closed space in which the fuel generating member 1 and the fuel electrode 2B are disposed (connected to the flow path, Since there is no outflow of gas, the total number of molecules of gas existing in the closed space in a broad sense) may be kept constant.

  In the fuel cell system obtained by the manufacturing method of each embodiment described above, one fuel cell unit 2 performs both power generation and electrolysis of water, but the fuel generating member 1 is a fuel cell (for example, dedicated to power generation). A solid oxide fuel cell) and a water electrolyzer (for example, a solid oxide fuel cell dedicated to water electrolysis) may be connected in parallel on the gas flow path.

DESCRIPTION OF SYMBOLS 1 Fuel generating member 2 Fuel cell part 2A Electrolyte membrane 2B Fuel electrode 2C Air electrode 3 Container 3_1 1st package member 3_2 2nd package member 3_3 Sealing member 3A 1st opening part 3B 2nd opening part 4 1st 5 First valve 6 Second pipe 7 Second valve 8 Hydrogen supply device 9, 13 Piping 10 Pressure regulator 11, 12 Fitting 14 Exhaust device 15 Gas concentration detection sensor 16 Shape change member 17 Heat resistant inorganic adhesive 18 Heating furnace

Claims (4)

A fuel cell system manufacturing method comprising: a fuel generating member that generates fuel by a chemical reaction; and a fuel cell unit that generates electric power by a reaction between an oxidant containing oxygen and fuel supplied from the fuel generating member,
A forming step of forming a space in which the fuel electrode of the fuel cell unit and the fuel generating member are disposed inside, and at least two gas circulation units capable of flowing gas between the inside and the outside are provided;
After the forming step, the gas in the space is made up of a first gas of the same kind as the fuel, a second gas of the same kind as the oxide of the fuel, or a first gas and a second gas using the gas circulation section. Replacement with a mixed gas, and the total number of molecules of the gas existing in the space is adjusted so that the total pressure of the gas existing in the space is smaller than the atmospheric pressure when the space is at room temperature Process,
A method of manufacturing a fuel cell system comprising: a closing step of closing the gas circulation part to make the space closed after the replacement step.   In the replacement step, the total number of molecules of the gas existing in the space is adjusted by adjusting the total pressure of the gas existing in the space to be lower than the atmospheric pressure in a state where the space is at room temperature. The method of manufacturing a fuel cell system according to claim 1, wherein adjustment is performed.   In the replacement step, the total number of molecules of the gas existing in the space is adjusted by adjusting the total pressure of the gas existing in the space to atmospheric pressure in a state where the space is higher than room temperature. The method of manufacturing a fuel cell system according to claim 1, wherein: The fuel is hydrogen;
The said closing process WHEREIN: The said gas distribution part is closed in multiple using a mutually different several closing method with respect to each of the said gas distribution part, The Claim 1 characterized by the above-mentioned. Manufacturing method of fuel cell system.