JP2012113876A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system that is easy to miniaturize and can stably generate power by stably supplying oxidant gas to a fuel cell.SOLUTION: The fuel cell system includes: a fuel cell 100 in which a plurality of membrane electrode assemblies each having a cathode with a cathode catalyst layer for reducing oxygen, an anode with an anode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane arranged between the cathode and the anode are stacked via separators; an oxidant gas passage formed on one principal surface of each separator and provided with a supply opening and an exhaust opening for oxidant gas; a supplying air feed part 91 for supplying oxidant gas to the supply opening of the oxidant gas passage; and an exhausting air feed part 90 for exhausting the oxidant gas in the oxidant gas passage out from the exhaust opening of the oxidant gas passage.

Description

  The present invention relates to a fuel cell system, and more particularly, to an oxidant gas supply mechanism for a fuel cell that is easily downsized and stably generates power.

  The polymer electrolyte fuel cell (PEFC) operates at low temperatures from room temperature to 100 ° C or less, and has features such as quick start / stop and high power density. It is expected to be used as a power generator for mobile devices such as cogeneration and automobiles, and as a portable power source.

  A general PEFC is formed by laminating a plurality of electrode / electrolyte assemblies (MEA) consisting of a positive electrode, a negative electrode, and a solid polymer electrolyte membrane as an electrolyte. Each MEA is stacked in a state of being sandwiched between two types of separators, a positive electrode side separator in which an oxygen channel (oxidant gas channel) is formed and a negative electrode side separator in which a fuel channel is formed. In some cases, a flow path for circulating a cooling medium is formed between the negative electrode side separator and the positive electrode side separator. In this case, normally, three flow paths, that is, an oxygen flow path, a coolant flow path, and a fuel flow path, are formed in the MEA stacking direction within a pair of separators.

  Since the oxygen flow path, the cooling medium flow path, and the fuel flow path are usually formed by providing grooves on the surface of the separator, each separator needs a certain thickness. However, a cell stack configured by stacking a plurality of MEAs sandwiched between separators having a certain thickness is bulky.

  Further, the separator requires a fuel supply manifold, a fuel discharge manifold, an oxygen supply manifold, an oxygen discharge manifold, a cooling medium supply manifold, and a cooling medium discharge manifold penetrating in the stacking direction (for example, Patent Document 1). The electrode that overlaps with the separator needs to have a portion that can directly participate in power generation in a region other than the position corresponding to each manifold forming portion of the separator. It is difficult to take big.

  In addition, such a PEFC is a fuel cell system that generates electricity by forcibly supplying an oxidant gas (air containing oxygen) to a cell stack using an air supply means such as an air compressor or a pneumatic pump. It has been proposed (for example, Patent Document 2). However, when such a PEFC is used as a portable power source, it is difficult to use it in a portable fuel cell because the volume and weight are limited.

  In order to solve such problems, a plurality of oxidant gas flow paths are formed in a straight line from one end to the opposite end on the surface of the separator that is in contact with the positive electrode, separately from the fuel flow path of the fuel cell. The cross-sectional area of the oxidant gas flow path is reduced from the supply port of the oxidant gas to the exhaust port, and an oxidant gas is installed at the exhaust port. A compact semi-passive type fuel cell system that generates electricity by supplying the gas into the flow path has been proposed (for example, Patent Document 3).

JP 2006-310288 A JP 2006-164766 A Japanese Patent No. 3356721

  However, even in the fuel cell described in Patent Document 3, since the fuel flow path for supplying fuel to the negative electrode is formed in the separator, there is a limit to downsizing in the cell stacking direction. Furthermore, Patent Document 3 does not show the interval between the fuel cell and the air supply unit. When the distance between the fuel cell and the air supply unit is small, the oxidant gas tends to be biased toward the flow path close to the air supply unit, and the power generation efficiency may be reduced. When the distance between the fuel cell and the air supply unit is large, it is insufficient to reduce the volume of the entire fuel cell including the air supply unit.

  The present invention has been made to solve the above problems, and provides a fuel cell system that can be easily miniaturized and can stably generate power.

  In order to solve the above problems, a fuel cell system according to the present invention is arranged between a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and the positive electrode and the negative electrode. A fuel cell formed by laminating a plurality of electrode / electrolyte integrated materials having a solid polymer electrolyte membrane through a separator, and a supply port and an exhaust port for an oxidant gas formed on one main surface of the separator An oxidant gas flow path, a supply air supply section for supplying the oxidant gas to the supply port of the oxidant gas flow path, and an oxidant gas in the oxidant gas flow path of the oxidant gas flow path. And a discharge air supply section that discharges to the outside from the discharge port.

  According to the present invention, it is possible to provide a fuel cell system that can be easily downsized, stably supply an oxidant gas to the fuel cell, and perform stable power generation.

It is a schematic perspective view which shows an example of the fuel cell system of this invention. It is a schematic perspective view which shows an example of the fuel cell of this invention. It is the II sectional view taken on the line of the fuel cell system shown in FIG. FIG. 3 is an exploded perspective view of a main part of the fuel cell shown in FIG. 2. FIG. 3 is a partial cross-sectional view of a main part of the fuel cell shown in FIG. 2. It is a schematic block diagram which shows an example of a separator, FIG. 6A is a top view, FIG. 6B is the II-II sectional view taken on the line of FIG. 6A, C is a bottom view. It is a schematic block diagram which shows an example of the laminated body of a positive electrode catalyst layer, a solid polymer electrolyte membrane, and a negative electrode catalyst layer which comprises an electrode-electrolyte integrated object, FIG. 7A is a top view, FIG. 7B is III-III of FIG. 7A. It is line sectional drawing. It is a schematic block diagram which shows an example of the positive electrode diffusion layer and positive electrode gas seal which comprise an electrode-electrolyte integrated material, FIG. 8A is a top view, FIG. 8B is the IV-IV sectional view taken on the line of FIG. It is a schematic block diagram which shows an example of the negative electrode diffusion layer and negative electrode gas seal which comprise an electrode-electrolyte integrated material, FIG. 9A is a top view, FIG. 9B is the VV sectional view taken on the line of FIG. 9A. It is a schematic perspective view which shows the other example of the fuel cell system of this invention. It is a schematic block diagram which shows an example of the fuel cell power generation system using the fuel cell system of this invention. It is a schematic perspective view which shows an example of a gas-liquid separation container. It is a perspective view which shows schematic structure of the fuel cell system of the comparative example 1. FIG. FIG. 14 is a sectional view taken along line VI-VI of the fuel cell system shown in FIG. 13. It is a figure which shows the result of the electric power generation characteristic in the fuel cell power generation system of Example 1 and Comparative Example 1.

  The fuel cell system of the present invention includes a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane disposed between the positive electrode and the negative electrode. A fuel cell formed by stacking a plurality of electrode / electrolyte integrated bodies having a separator through a separator, an oxidant gas flow path formed on one main surface of the separator and having an oxidant gas supply port and a discharge port; A supply air supply section for supplying an oxidant gas to the supply port of the oxidant gas flow path, and an oxidant gas in the oxidant gas flow path to be discharged to the outside from the discharge port of the oxidant gas flow path And a discharge air supply unit. As a result, the distance between the exhaust air supply unit and the fuel cell can be shortened, so that the fuel cell can be downsized in the air supply direction, and the fuel cell can stably supply oxidant gas and stably generate power. The system can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. Further, in this specification, a fuel cell having an air supply section is referred to as a “fuel cell system”, and a fuel cell system having a hydrogen production device, a gas-liquid separator, a hydrogen consuming device, etc. Battery generation system ".

(Embodiment 1)
In the first embodiment, an example of the fuel cell system of the present invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing an example of the fuel cell system of the present embodiment. FIG. 2 is a schematic perspective view showing an example of a fuel cell in the fuel cell system of the present embodiment. 3 is a cross-sectional view taken along line II of the fuel cell system shown in FIG. 1-3, the same code | symbol is attached | subjected about the same component. In the cross-sectional view of FIG. 3, the oxidant gas flow path is omitted, and the air supply units 90 and 91 are simplified. Moreover, hatching is abbreviate | omitted in sectional drawing of FIG.

  As shown in FIG. 1, the fuel cell system 101 of this embodiment includes a supply air supply unit 91, a discharge air supply unit 90, a fuel cell 100, and ducts 80 and 80.

  The supply air supply section 91 is installed on the oxidant gas supply port 51 (FIG. 3) side, and the oxidant gas (for example, air containing oxygen) is supplied to the oxidant gas supply port 51 (FIG. 3). To supply. The discharge air supply section 90 is installed on the oxidant gas exhaust port 52 (FIG. 3) side, and discharges the oxidant gas in the oxidant gas flow path from the oxidant gas discharge port 52 to the outside. Is. Further, as shown in FIG. 3, the supply air supply section 91 and the discharge air supply section 90 are connected by a duct 80 so as to seal the supply port 51 and the exhaust port 52 of the oxidant gas. In FIG. 3, the arrows indicate the direction in which the oxidant gas is supplied.

  The supply air supply unit 91 and the discharge air supply unit 90 are not particularly limited as long as they can blow air. For example, a DC fan, an AC fan, a blower, a small compressor, and the like can be used. From the viewpoint of space saving, a small fan and a blower are preferably used.

Further, the air volume of the supply air supply section 91 and the discharge air supply section 90 varies depending on the output of the fuel cell 100, the size of the exhaust port for the oxidant gas, the static pressure of the air supply section to be used, etc. Although it cannot be determined, a range of 0.05 m ³ / min to 0.5 m ³ / min and a static pressure of 10 Pa to 100 Pa are preferably used.

  Furthermore, it is desirable that the air flow rate of the supply air supply unit 91 and the discharge air supply unit 90 is adjusted so that the temperature of the fuel cell is within a certain range. In order to prevent the solid polymer electrolyte membrane from being dried and to prolong the life of the fuel cell, the temperature of the fuel cell is desirably 70 ° C. or less, more preferably 60 ° C. or less. In order to prevent moisture generated by power generation from condensing, the temperature of the fuel cell is preferably 30 ° C. or higher, more preferably 40 ° C. or higher. In other words, it is most desirable that the temperature of the fuel cell during power generation is kept around 50 ° C.

  Here, when the relationship between the air volume of the supply air supply unit 91 and the discharge air supply unit 90 and the temperature and output of the fuel cell 100 was examined, the supply air supply unit 91 and the discharge air supply unit 90 were driven. When the voltage was 12 V, the temperature of the fuel cell 100 was 54 ° C., and the output of the fuel cell 100 was 32 W. On the other hand, when the driving voltage of the supply air supply unit 91 and the discharge air supply unit 90 is 16 V, the temperature of the fuel cell 100 is 51 ° C., and the output of the fuel cell 100 is 38 W. From this, it can be seen that the output of the fuel cell is improved by increasing the air flow by increasing the driving voltage of the air supply section. This is presumably because the output of the fuel cell was improved because the temperature of the fuel cell was lowered and the drying of the solid polymer electrolyte membrane was suppressed due to the increase in the air volume of the air supply section.

  As shown in FIG. 2, the fuel cell 100 has a plurality of electrode / electrolyte integrated bodies (hereinafter referred to as MEAs) 20 stacked via separators 10, and generates power using hydrogen as fuel. Moreover, the laminated body which consists of several MEA20 laminated | stacked through the separator 10 is clamped by the two end plates 50, and is being fixed with the volt | bolt and the nut. Also, a fuel supply port 60 and a fuel discharge port 70 are provided in one of the two end plates (the upper end plate 50 in FIG. 2). The fuel is introduced into the fuel cell 100 from the fuel supply port 60, supplied to the negative electrode of each MEA 20, and used for power generation. Further, the fuel not consumed by each MEA 20 is discharged out of the fuel cell 100 from the fuel discharge port 70.

  Ducts 80 and 80 are provided so as to cover the entire two opposing side surfaces of fuel cell 100. In the present embodiment, the ducts 80 and 80 are disposed so as to be in contact with the upper and lower end plates 50 and 50, and together with the supply air supply unit 91 and the discharge air supply unit 90, the supply port 51 ( 3) and the exhaust port 52 (FIG. 3) are arranged to be sealed. The duct is not particularly limited as long as it is a material that does not leak or crack when the oxidant gas is supplied. For example, metal materials such as aluminum and stainless steel or resin materials such as polycarbonate, polyetheretherketone, acrylic and polystyrene can be used. From the viewpoint of ease of molding and weight reduction, resin materials such as polycarbonate Are preferably used.

  Hereinafter, the principal part of the fuel cell 100 will be described in detail with reference to FIGS. 4 and 5. 4 is an exploded perspective view of the main part of the fuel cell 100 shown in FIG. 2, and FIG. 5 is a partial cross-sectional view of the main part of the fuel cell 100 shown in FIG. 4 and 5, the same components as those in FIG. 2 are denoted by the same reference numerals. FIG. 5 is a cross-sectional view, but for the purpose of facilitating understanding of the fuel flow path formed by the fuel supply manifold and the fuel discharge manifold of each component described later, the upper end and the lower side of the upper separator 10. The back portion is omitted except for the lower end of the separator 10.

  As shown in FIGS. 4 and 5, the MEA 20 is obtained by sequentially stacking a positive electrode diffusion layer 21, a laminate 20 a, and a negative electrode diffusion layer 25 from above, and separators 10 and 10 are disposed above and below the MEA 20. Has been.

  As shown in FIG. 5, the stacked body 20 a is formed by sequentially stacking a positive electrode catalyst layer 22, a solid polymer electrolyte membrane 23, and a negative electrode catalyst layer 24 from the top. Details of each layer will be described later.

  The separator 10 has a quadrangular shape in plan view and is formed of a single member. The separator 10 is formed with a fuel supply manifold 11 and a fuel discharge manifold 12 serving as fuel flow paths. The fuel supply manifold 11 is formed in the vicinity of one of the four sides forming the quadrangle, and the fuel discharge manifold 12 is formed in the vicinity of one side facing the one side.

  In addition, a plurality of groove-like oxidant gas flow paths 13 are formed on one main surface (here, the lower surface) of the separator 10, and the other main surface (here, the upper surface) is flat. The plurality of oxidant gas flow paths 13 are linearly formed on one main surface (lower surface) of the separator 10 on two sides other than the two opposite sides formed in the vicinity of the fuel supply manifold 11 and the fuel discharge manifold 12. Are formed in parallel or substantially parallel to each other. Further, both end portions of the oxidant gas flow path 13 are opened at the side surfaces of the separator 10, and the respective opening portions serve as an oxidant gas supply port 51 (FIG. 3) and a discharge port 52 (FIG. 3).

  Further, the positive electrode catalyst layer 22, the solid polymer electrolyte membrane 23, and the negative electrode catalyst layer 24 constituting the laminate 20 a are also disposed at positions corresponding to the fuel supply manifold 11 and the fuel discharge manifold 12 formed in the separator 10. A supply manifold and a fuel discharge manifold are respectively formed. This will be described later.

  The positive electrode diffusion layer 21 is disposed so as to cover the entire surface of the separator 10 located on the upper side in FIG. The positive electrode diffusion layer 21 has a quadrangular shape in plan view, and the fuel gas is present outside the two sides that are parallel or substantially parallel to the oxidant gas flow path 13 among the four sides constituting the quadrangle. A positive electrode gas seal 30 for suppressing outflow is disposed. The positive gas seal 30 is formed with a fuel supply manifold and a fuel discharge manifold at positions corresponding to the fuel supply manifold 11 and the fuel discharge manifold 12 formed in the separator 10.

  The negative electrode diffusion layer 25 is disposed in contact with the flat plate surface (upper surface) of the separator 10 located on the lower side in FIG. The negative electrode diffusion layer 25 has a quadrangular shape in plan view, and a negative gas seal 40 for suppressing the outflow of fuel gas is disposed on the outer periphery of the square. The negative gas seal 40 is formed with a fuel supply manifold and a fuel discharge manifold at positions corresponding to the fuel supply manifold 11 and the fuel discharge manifold 12 formed in the separator 10.

  Next, the flow of oxidant gas and fuel will be described with reference to FIGS. 4 and 5, the flow of the oxidant gas is indicated by a dotted arrow, and the flow of the fuel is indicated by a solid arrow.

  When introduced into the oxidant gas flow path 13, the oxidant gas is supplied to the positive electrode catalyst layer 22 through the positive electrode diffusion layer 21. Further, the oxidant gas that is not involved in the power generation reaction and is not consumed is discharged to the outside through the oxidant gas flow path 13. More specifically, as described above, the oxidant gas flow path 13 is formed so as to linearly connect two opposing sides of the separator 10 having a quadrangular shape in plan view. However, since the opening is formed on the side surface of the separator, for example, oxygen is used using a fan or the like from one opening end of the oxidant gas flow path 13 in the separator 10, that is, from the oxidant gas supply port 51 (FIG. 3) side. The air can be introduced into the oxidant gas flow path 13 by sending the air containing. The air (oxygen) introduced into the oxidant gas flow path 13 is supplied to the positive electrode catalyst layer 22 through the positive electrode diffusion layer 21 of the MEA 20. In addition, oxygen that has not been consumed because it is not involved in the power generation reaction and components other than oxygen in the air are the other opening end of the oxidant gas flow path 13, that is, the oxidant gas exhaust 52 (FIG. 3) side. Will be discharged to the outside.

  When introduced into the fuel supply manifold 11, the fuel is supplied to the negative electrode catalyst layer 24 through the negative electrode diffusion layer 25. Further, the fuel that is not involved in the power generation reaction and not consumed is discharged from the fuel discharge manifold 12 to the outside through the negative electrode diffusion layer 25. More specifically, the negative electrode diffusion layer 25 according to the negative electrode is generally composed of a material that allows fuel to flow through, such as a water-repellent porous carbon sheet. Therefore, when the fuel cell of the present invention is used, for example, in a state where the fuel supply pressure is relatively low, the fuel introduced from the fuel supply manifold 11 passes through the holes in the negative electrode diffusion layer 25 and the negative electrode catalyst layer 24. The fuel that has been supplied to and not consumed without being involved in the power generation reaction is discharged from the fuel discharge manifold 12 to the outside through the hole in the negative electrode diffusion layer 25. In this case, as shown in FIG. 4 and FIG. 5, the separator 10 interposed between adjacent MEAs 20 only needs to form the oxidant gas flow path 13, and it is not necessary to form the fuel flow path. The separator can be composed of a single member, and the separator itself can be made thin. Therefore, the fuel cell of the present invention can be made compact in the stacking direction. On the other hand, when the fuel cell of the present invention is used, for example, in a state where the fuel supply pressure is relatively high, the fuel supply manifold 11 and the fuel discharge manifold 12 are provided on the surface of the negative electrode diffusion layer 25 as described later. It is preferable to form a plurality of groove-like fuel flow paths connected in a straight line in parallel or substantially in parallel. In this case, damage to the negative electrode diffusion layer can also be suppressed.

  In the fuel cell shown in FIGS. 4 and 5, the air passing through the oxidant gas flow path 13 also acts as a cooling medium. That is, the oxidant gas flow path 13 also serves as a cooling medium flow path. Therefore, it is not necessary to separately form a cooling medium flow path in the separator, and cooling with the cooling medium is possible even if the separator is constituted by a single member layer and the one side is flat and the separator is thin.

  Here, the reason why the fuel cell system 101 of the present embodiment shown in FIGS. 1 and 3 includes the air supply portions 91 and 90 on the supply port 51 side and the exhaust port 52 side of the oxidant gas flow path will be described.

  In order to generate power in the fuel cell 100, it is necessary to supply an oxidant gas (in this case, oxygen-containing air) to the positive electrode, but in the past (Patent Document 3), oxidation is performed as shown in FIGS. An air supply unit 90 is installed on the exhaust port 52 side of the agent gas, and air is supplied from the supply port 51 side to the exhaust port 52 side to supply the positive electrode diffusion layer 21 constituting the positive electrode. However, when the air supply unit is installed only on the exhaust port 52 side, the air supply amount is different between the supply port 51 and the exhaust port 52, the oxidant gas becomes non-uniform in the same cell during power generation, and the power generation efficiency decreases. There is a risk that stable power generation cannot be performed.

  Therefore, in this embodiment, as shown in FIGS. 1 and 3, an air supply unit 91 is also installed on the oxidant gas supply port 51 side so that air is forcibly supplied from the supply port 51 side. did. In this case, the air supplied by the air supply unit 91 hits the rib 14 of the separator 10, and an air flow is generated in the space between the air supply unit 91 and the supply port 51, resulting in a slightly pressurized state. The air spreads over the entire side surface of the fuel cell 100 on the supply port 51 side. In this state, if air is supplied in the direction of exhausting air from the inside of the fuel cell 100 to the outside by the air supply unit 90, the non-uniform air supply that occurs when the air supply unit is installed only on the exhaust port 52 side described above. The air condition can be avoided, the power generation efficiency can be improved, and the power can be generated stably.

  Here, when the influence on the output of the fuel cell by the arrangement position of the air supply unit was examined, when two air supply units were provided only on the exhaust port 52 side, the average output of the fuel cell was 29 W. . On the other hand, when one air supply unit was provided for each of the supply port 51 and the exhaust port 52, the average output of the fuel cell was 32W. Thus, it can be seen that the output of the fuel cell is improved when the air supply section is provided not only on the exhaust port 52 side but also on the supply port 51 side. Therefore, in the present invention, the air supply section is provided at both the exhaust port 52 and the supply port 51 for the oxidant gas.

  The distance between the supply air supply unit 91 and the supply port 51 and the distance between the discharge air supply unit 90 and the exhaust port 52 are the length in the long side direction of the fuel cell 100 to be installed and the air supply used. Since it changes depending on the air volume and static pressure of the part, it is not limited, but if it is between 5 mm and 10 mm, it does not particularly affect power generation. As described above, when the air supply unit is installed only on the exhaust port 52 side, the distance between the air supply unit and the exhaust port 52 is set to 15 mm or more from the viewpoint of power generation efficiency. By providing the air supply portion in both the exhaust port 52 and the supply port 51, it is possible to stably generate power even if the distance between the air supply portion and the exhaust port 52 is shortened to 5 mm to 10 mm. As a result, the volume of the entire fuel cell system can be reduced.

  The position of the supply air supply unit 91 is not particularly limited as long as an air flow can be generated between the supply air supply unit 91 and the supply port 51.

  FIG. 6 is a schematic configuration diagram illustrating an example of the separator 10 illustrated in FIGS. 4 and 5. 6A is a plan view showing a surface of the separator 10 where the oxidant gas flow path 13 is not formed (surface on the side in contact with the negative electrode diffusion layer), and FIG. 6B is a cross-sectional view taken along the line II-II in FIG. 6A. FIG. 6C is a plan view showing the surface of the separator 10 on the side where the oxidant gas flow path 13 is formed (the surface on the side in contact with the positive electrode diffusion layer).

  The fuel supply manifold 11 and the fuel discharge manifold 12 are respectively disposed in the vicinity of two opposing sides of the four sides of the separator 10 having a quadrangular shape in plan view. Further, the fuel supply manifold 11 and the fuel discharge manifold 12 of the separator 10 are arranged as described above, and the fuel supply manifold 11 and the fuel discharge manifold 12 of the separator 10 are also applied to the positive electrode, the negative electrode, and the solid polymer electrolyte membrane that constitute the MEA 20. By forming the fuel supply manifold and the fuel discharge manifold at positions corresponding to the above, it is possible to make a larger area where the fuel flows in the negative electrode, that is, the area sandwiched between the fuel supply manifold and the fuel discharge manifold. The electrode area that can be favorably involved in power generation can be increased, and power can be generated more efficiently. In a fuel cell using hydrogen as a fuel, water generated during power generation and water contained in the fuel may stay in the negative electrode and hinder the subsequent power generation reaction. By arranging the manifold as described above, the fuel flows in a straight line from the fuel supply manifold to the fuel discharge manifold at almost all points of the negative electrode. Can be discharged to the outside well, and a decrease in power generation efficiency due to water remaining in the negative electrode can be suppressed.

  One main surface (upper surface) of the separator 10 is planar as shown in FIG. 6A. On the other main surface (lower surface), as shown in FIG. 6C, of the four sides forming a quadrangle in plan view, the two opposite sides where the fuel supply manifold 11 and the fuel discharge manifold 12 are formed in the vicinity A plurality of oxidant gas passages 13 connecting two other sides in a straight line are formed in parallel or substantially parallel to each other. The oxidant gas flow path 13 has a groove shape, and ribs 14 exist between adjacent oxidant gas flow paths 13. In FIG. 6C, the oxidant gas flow path 13 is shown with dots in order to make it easy to distinguish the oxidant gas flow path 13 and the rib 14. In the oxidant gas flow path related to the separator, “parallel to or substantially parallel to each other” basically means that the oxidant gas flow paths are formed in parallel to each other, but even if they are slightly deviated from parallel. In the range that does not impair the effects of the present invention, it is acceptable.

  The length of the separator 10 in the direction of the oxidant gas flow path 13 (the length in the vertical direction in FIGS. 6A and 6C) is preferably 10 mm or more from the viewpoint of ensuring a sufficient electrode area. In addition, as described above, the gas passing through the oxidant gas flow path 13 can serve as a cooling medium in addition to being a supply source of oxygen (oxidant gas), for example. If the length in the flow path direction is too long, the heat generated during power generation of the fuel cell may not be sufficiently cooled by the gas passing through the oxidant gas flow path. Therefore, the length of the separator 10 in the direction of the oxidant gas flow path 13 is preferably 100 mm or less.

  The distance between the fuel supply manifold 11 and the fuel discharge manifold 12 in the separator 10 (the shortest distance; the same applies hereinafter for the distance between the fuel supply manifold 11 and the fuel discharge manifold 12) ensures a sufficient electrode area. It is preferable that it is 10 mm or more from a viewpoint to do. Further, if the distance between the fuel supply manifold 11 and the fuel discharge manifold 12 is too long, the fuel flow path may become long and the fuel flow pressure loss may increase. Therefore, the distance between the fuel supply manifold 11 and the fuel discharge manifold 12 in the separator 10 is preferably 300 mm or less.

  The width of the fuel supply manifold 11 and the fuel discharge manifold 12 in the separator 10 (the length in the lateral direction in FIGS. 6A and 6C) can secure a gas sealing property to be described later in order to reduce the pressure loss during fuel flow. It is preferable to make it as large as possible within the range.

  As described above, the fuel supply manifold 11 and the fuel discharge manifold 12 are respectively provided in the vicinity of two opposite sides of the four sides of the separator 10 having a quadrangular shape in plan view. 6A and 6C, the fuel supply manifold 11 is preferably arranged so that the distance from the vertical side on the left side is as short as possible within a range in which gas sealability described later can be secured. In addition, it is preferable that the fuel discharge manifold 12 be as short as possible from the vertical side on the right side within the range in which gas sealing performance described later can be secured in FIGS. 6A and 6C.

  In the fuel cell of the present invention, the fuel supply manifold and the fuel discharge manifold formed on the positive electrode, the negative electrode, and the solid polymer electrolyte membrane constituting the MEA are located at the positions where the fuel supply manifold and the fuel discharge manifold of the separator exist as described above. Place in the corresponding place. Thereby, the fuel supply manifold formed in the separator and the MEA overlaps, and the fuel discharge manifold formed in the separator and the MEA overlaps, so that the fuel flow path in the thickness direction of the fuel cell (separator and MEA stacking direction). Is formed.

  In determining the fuel supply manifold and fuel discharge manifold formed in the MEA, and the formation positions of the fuel supply manifold and fuel discharge manifold formed in the separator, the widths of the positive electrode gas seal and the negative electrode gas seal described later should be considered. preferable.

  The width of the oxidant gas channel 13 (the length in the lateral direction in FIGS. 6B and 6C) is preferably 0.5 mm or more from the viewpoint of improving the gas flow. From the viewpoint of suppressing the strength reduction, the thickness is preferably 5 mm or less.

  The height of the oxidant gas flow path 13 (depth of the groove) is preferably 0.5 mm or more from the viewpoint of improving the gas flow, and also suppresses the increase in the thickness of the separator 10. From the above, it is preferable to be 5 mm or less.

  The width of the rib 14 (the length in the horizontal direction in FIGS. 6B and 6C) between the adjacent oxidant gas flow paths 13 is 0.5 mm or more from the viewpoint of suppressing the strength reduction of the separator 10. From the viewpoint of improving the gas flow in the oxidant gas flow path 13, it is preferably 5 mm or less.

  The thickness of the thinnest part of the oxidant gas channel 13 portion (in FIG. 6B, the length from the top surface of the groove-like oxidant gas channel 13 formed on the lower surface of the separator 10 to the upper surface of the separator 10) is From the viewpoint of ensuring the strength of the separator 10 and preventing cracking, distortion, etc., it is preferably 0.2 mm or more, and from the viewpoint of suppressing an increase in the thickness of the separator 10, it is preferably 5 mm or less. .

  The material of the separator 10 is not particularly limited as long as it has high electron conductivity and corrosion resistance. For example, graphite, a mixture of carbon and resin, stainless steel, stainless steel plated with gold or platinum, Preferred are titanium, titanium plated with gold or platinum, stainless steel-copper clad, stainless steel-copper clad plated with gold or platinum, and the like.

  FIG. 7 is a schematic configuration diagram illustrating an example of a stacked body 20 a of the positive electrode catalyst layer 22, the solid polymer electrolyte membrane 23, and the negative electrode catalyst layer 24 that constitute the MEA 20 illustrated in FIGS. 4 and 5. 7A is a plan view, and FIG. 7B is a sectional view taken along line III-III in FIG. 7A.

  The positive electrode catalyst layer 22, the solid polymer electrolyte membrane 23, and the negative electrode catalyst layer 24 constituting the laminate 20a preferably have the same shape in plan view as shown in FIG. Thereby, the thickness of the laminate 20a composed of the positive electrode catalyst layer 22, the solid polymer electrolyte membrane 23, and the negative electrode catalyst layer 24 can be made uniform, so that the positive and negative electrode diffusion layers and the positive and negative electrode gas seals are interposed. The tightening by the separators (two separators disposed on the upper and lower surfaces of the MEA) becomes uniform, and gas leakage can be suppressed more favorably. Further, when the MEA is manufactured, there is no need to accurately determine the positions of the positive electrode catalyst layer 22 and the negative electrode catalyst layer 24 with the solid polymer electrolyte membrane 23 interposed therebetween. It becomes easy and the productivity can be increased.

  The laminate 20a has a quadrangular shape in plan view, and a fuel supply manifold 201 is formed in the vicinity of one of the four sides constituting the quadrangle, and in the vicinity of one side facing the one side. A fuel discharge manifold 202 is formed.

  FIG. 8 is a schematic configuration diagram illustrating an example of the positive electrode diffusion layer 21 and the positive electrode gas seal 30 illustrated in FIG. 4. 8A is a plan view, and FIG. 8B is a sectional view taken along line IV-IV in FIG. 8A.

  As described above, the positive electrode diffusion layer 21 is disposed so as to cover the entire surface of the separator on which the oxidizing gas channel is formed. The positive electrode diffusion layer 21 has a quadrangular shape in plan view, and two of the four sides constituting the quadrangle are parallel or substantially parallel to the oxidant gas flow path of the separator (vertical 2 in FIG. 8A). The positive electrode gas seal 30 for suppressing the outflow of the fuel gas is disposed outside the side. Therefore, the positive electrode gas seal 30 does not exist at the position corresponding to the open end of the oxidant gas flow path of the separator, and the stress of expansion and contraction of the solid polymer electrolyte membrane that can be caused by pressure or moisture due to fuel can be relieved. it can.

  In addition, a fuel supply manifold 31 and a fuel discharge manifold 32 are formed in the positive electrode gas seal 30.

  The position of the interface between the positive electrode diffusion layer 21 and the positive electrode gas seal 30 may be a position corresponding to the outer side in the longitudinal direction (the fuel supply manifold side and the fuel discharge manifold side) with respect to the formation surface of the oxidant gas flow path of the separator. preferable. If the interface exists at a position corresponding to the oxidant gas flow path of the separator or at a position corresponding to a rib between the oxidant gas flow path and the oxidant gas flow path adjacent thereto, the gas sealing property May decrease.

  The width of the positive electrode gas seal 30 (the length of a and b in FIG. 8A) is preferably 0.5 mm or more from the viewpoint of improving the gas sealability, and also reduces the loss of the electrode area. From the viewpoint of doing, it is preferably 5 mm or less.

  The thickness of the positive electrode diffusion layer 21 is preferably 100 to 1000 μm. Moreover, it is preferable that the thickness of the positive electrode gas seal 30 is 50-1000 micrometers.

  FIG. 9 is a schematic configuration diagram illustrating an example of the negative electrode diffusion layer 25 and the negative electrode gas seal 40 illustrated in FIG. 4. 9A is a plan view, and FIG. 9B is a cross-sectional view taken along line VV in FIG. 9A.

  As described above, the negative electrode diffusion layer 25 is disposed so as to be in contact with the flat plate surface of the separator (the surface on the side opposite to the surface on which the oxidizing gas channel is formed). The negative electrode diffusion layer 25 has a quadrangular shape in plan view, and a negative electrode gas seal 40 for suppressing the outflow of fuel gas is disposed outside the outer periphery of the square. A fuel supply manifold 41 is formed by one of the four sides constituting the quadrangle (the vertical side on the left side in FIG. 9A) and the negative gas seal 40, and one side (see FIG. A fuel discharge manifold 42 is formed by the vertical side) of 9A and the negative electrode gas seal 40.

  As described above, the negative electrode diffusion layer 25 is generally made of a material having pores through which fuel gas can flow, but in this embodiment, the negative electrode diffusion layer 25 and the negative electrode gas seal 40 are used. By arranging the fuel supply manifold 41 and the fuel discharge manifold 42 as described above, a fuel flow path from the fuel supply manifold 41 to the fuel discharge manifold 42 is formed in the entire negative electrode diffusion layer 25. For this reason, for example, when a fuel with a large amount of water is supplied into the negative electrode or when water is accumulated in the negative electrode due to power generation, the water can be discharged well. It becomes like this.

  Note that it is not always necessary to form a fuel flow path in the negative electrode diffusion layer 25. When the fuel flow path is not formed, the entire surface of one main surface (the lower surface in FIG. 4) of the negative electrode diffusion layer 25 is in contact with the separator 10 (FIG. 4), so that the electrical contact resistance is minimized. It becomes possible to suppress to. On the other hand, for example, when the supply pressure of the fuel gas is relatively high, the negative electrode diffusion layer may be damaged. Therefore, the fuel supply manifold 41 is provided on the other main surface (upper surface in FIG. 4) of the negative electrode diffusion layer 25. It is also possible to form a plurality of groove-like fuel passages that connect the fuel discharge manifold 42 and the fuel discharge manifold 42 in parallel or substantially in parallel to prevent damage to the negative electrode diffusion layer.

  The width of the negative electrode gas seal 40 (the length of c and d in FIG. 9A) is preferably 0.5 mm or more from the viewpoint of improving the gas sealability, and also reduces the loss of the electrode area. From the viewpoint of doing, it is preferably 5 mm or less.

  The thickness of the negative electrode diffusion layer 25 is preferably 100 to 1000 μm. Moreover, it is preferable that the thickness of the negative electrode gas seal 40 is 50-1000 micrometers.

  In this embodiment, the positive electrode diffusion layer and the negative electrode diffusion layer are made of a porous electronic conductive material, and for example, a porous carbon sheet subjected to a water repellent treatment is used. Fluorine resin particles (such as PTFE resin particles) are provided on the surface of the positive electrode diffusion layer on the side of the positive electrode catalyst layer and on the surface of the negative electrode diffusion layer on the side of the negative electrode catalyst layer for the purpose of further improving water repellency and improving contact with the catalyst layer. You may apply the paste of carbon powder containing.

  As materials for the positive electrode gas seal and the negative electrode gas seal, various materials known as sealing materials in the field of fuel cells, for example, silicon rubber, ethylene-propylene-diene rubber, PTFE film, polyimide film, and the like can be used.

  In the fuel cell of the present invention, in the MEA constituting the fuel cell, the positive electrode and the negative electrode may be configured to be electrically connected, for example, by connecting them with a lead body through a resistor and a switch. preferable. In the fuel cell having the MEA having such a configuration, when the power generation by the fuel cell is finished, the positive electrode and the negative electrode related to the MEA are short-circuited by, for example, turning on the above-described fuel, and the fuel such as hydrogen remaining in the fuel cell. Can be consumed. Therefore, deterioration of the fuel cell due to fuel remaining in the fuel cell at the end of power generation by the fuel cell can be suppressed.

  In the MEA related to the fuel cell, when the positive electrode and the negative electrode are configured to be able to conduct through the resistance as described above, for example, in the fuel cell power generation system, after the fuel cell is stopped, the MEA What is necessary is just to use what has a resistance value that the time required for the voltage between the positive electrode and the negative electrode to become 0.1 V or less within 1 minute, and without using a resistor, the MEA can be used in such a time. As long as the voltage between the positive electrode and the negative electrode can be lowered as described above, the connection may be made by connecting with a lead body or the like only through a switch without using a resistor.

  The positive electrode catalyst layer related to the MEA constituting the fuel cell has a function of reducing oxygen diffused through the positive electrode diffusion layer. The positive electrode catalyst layer contains, for example, a carbon powder carrying a catalyst (catalyst-carrying carbon powder) and a proton conductive material. Moreover, you may further contain binders, such as resin, as needed.

  The catalyst contained in the positive electrode catalyst layer is not particularly limited as long as it can reduce oxygen, and examples thereof include platinum fine particles. The catalyst may be fine particles composed of an alloy of platinum and at least one metal element selected from the group consisting of iron, nickel, cobalt, tin, ruthenium and gold.

As the carbon powder as the catalyst carrier, for example, carbon black having a BET specific surface area of 10 to 2000 m ² / g and an average particle diameter of 20 to 100 nm is used. The catalyst can be supported on the carbon powder by, for example, a colloid method.

  As a content ratio of the carbon powder and the catalyst, for example, the catalyst is preferably 5 to 400 parts by mass with respect to 100 parts by mass of the carbon powder. This is because such a content ratio can constitute a positive electrode catalyst layer having sufficient catalytic activity. In addition, for example, when the catalyst-supported carbon powder is produced by a method of depositing the catalyst on the carbon powder (for example, a colloid method), the catalyst diameter is as long as the carbon powder and the catalyst have the above content ratio. This is because it does not become too large and sufficient catalytic activity is obtained.

  The proton conductive material contained in the positive electrode catalyst layer is not particularly limited. For example, a resin having a sulfonic acid group such as a polyperfluorosulfonic acid resin, a sulfonated polyether sulfonic acid resin, or a sulfonated polyimide resin is used. be able to. Specific examples of the polyperfluorosulfonic acid resin include “Nafion (registered trademark)” manufactured by DuPont, “Flemion (registered trademark)” manufactured by Asahi Glass, and “Aciplex (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. Or the like.

  The content of the proton conductive material in the positive electrode catalyst layer is preferably 2 to 200 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. If the proton conductive material is contained in the above amount, sufficient proton conductivity is obtained in the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained. It is.

  The binder for the positive electrode catalyst layer is not particularly limited. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), fluoropolymers such as tetrafluoroethylene-ethylene copolymer (E / TFE), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE), polyethylene, polypropylene, nylon, polystyrene, polyester, Non-fluorinated resins such as ionomer, butyl rubber, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer and ethylene / acrylic acid copolymer can be used.

  The binder content in the positive electrode catalyst layer is preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. This is because if the binder is contained in the above-mentioned amount, sufficient binding properties can be obtained for the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained.

  The thickness of the positive electrode catalyst layer is preferably 1 to 50 μm.

  The negative electrode catalyst layer has a function of oxidizing a fuel such as hydrogen diffused through the negative electrode diffusion layer. The negative electrode catalyst layer contains, for example, a carbon powder carrying a catalyst (catalyst-carrying carbon powder) and a proton conductive material. Moreover, you may further contain binders, such as resin, as needed.

  The catalyst related to the negative electrode catalyst layer is not particularly limited as long as it can oxidize a fuel such as hydrogen. For example, each of the catalysts exemplified as the catalyst related to the positive electrode catalyst layer can be used. As for the carbon powder, proton conductive material, and binder related to the negative electrode catalyst layer, the above-described materials exemplified as the carbon powder, proton conductive material, and binder related to the positive electrode catalyst layer can be used.

  The thickness of the negative electrode catalyst layer is preferably 1 to 50 μm.

  The solid polymer electrolyte membrane is not particularly limited as long as it is made of a material that can transport protons and does not exhibit electronic conductivity. Examples of materials that can constitute the solid polymer electrolyte membrane include polyperfluorosulfonic acid resin, specifically, “Nafion (registered trademark)” manufactured by DuPont, and “Flemion (registered trademark)” manufactured by Asahi Glass. “Aciplex (trade name)” manufactured by Asahi Kasei Corporation. In addition, sulfonated polyether sulfonic acid resin, sulfonated polyimide resin, sulfuric acid-doped polybenzimidazole, and the like can also be used as the material for the solid polymer electrolyte membrane.

  The thickness of the solid polymer electrolyte membrane is preferably 5 to 150 μm.

(Embodiment 2)
In the second embodiment, another example of the fuel cell system of the present invention will be described. FIG. 10 is a schematic perspective view of the fuel cell system of the present embodiment. 10, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The difference from the first embodiment is that a plurality (two in this case) of the supply air supply section 91 and the discharge air supply section 90 are provided.

  In the present embodiment, the two supply air supply units 91 and 91 and the two discharge air supply units 90 and 90 can be controlled. For example, when the amount of fuel supplied to the negative electrode side of the fuel cell 100 is small, the positive electrode can be stopped by stopping each one of the two supply air supply units 91 and the two discharge air supply units 90 shown in FIG. Electricity can be generated by suppressing the supply amount of the oxidant gas supplied to the side.

  In this way, by controlling each of the plurality of supply air supply units 91 and the plurality of discharge air supply units 90, the air supply amount can be adjusted according to the power generation state of the fuel cell 100. Moreover, the electric power used for the supply air supply part and the discharge air supply part can also be suppressed. Furthermore, when the rectangular parallelepiped fuel cell 100 as shown in FIG. 10 is used, it is advantageous even when the oxidant gas is uniformly supplied to the entire cell.

(Embodiment 3)
In the third embodiment, an example of a fuel cell power generation system using the fuel cell system of the present invention will be described. FIG. 11 is a schematic configuration diagram showing an example of the fuel cell power generation system of the present embodiment.

  The fuel cell power generation system according to the present embodiment includes the fuel cell system 101 according to the first embodiment, the hydrogen production apparatus 600 that produces hydrogen as the fuel of the fuel cell 100, and the fuel gas in the fuel cell 100 discharged outside the system. Exhaust means (not denoted by reference numerals). Below, each component is demonstrated in detail.

<Fuel cell system>
The fuel cell system 101 according to the present embodiment has been described with reference to FIGS. 1 to 9 in the first embodiment, and thus description thereof is omitted here. In FIG. 11, broken line arrows indicate the flow direction of the gas supplied by the discharge air supply unit 90 and the supply air supply unit 91.

<Hydrogen production equipment>
The hydrogen production apparatus 600 according to the present embodiment includes a hydrogen generating substance storage container 603 that stores a hydrogen generating substance 604, a water storage container 601 that stores water 602, and water 602 in the water storage container 601. For example, a pump 201 serving as a transport unit for transporting to 603, a gas-liquid separation container 800 for separating the gas-liquid mixed fluid into a gas containing hydrogen and water, and water separated from the gas-liquid mixed fluid by the gas-liquid separation container 800 And a three-way valve 401 for collecting the water in the water storage container 601. The hydrogen production apparatus 600 produces hydrogen by causing an exothermic reaction between the hydrogen generating material 604 and the water 602. This hydrogen is supplied to the fuel cell 100 through the fuel flow path composed of the pipes 503, 504, and 505 and used as fuel.

  The material and shape of the hydrogen generating substance storage container 603 are not particularly limited as long as the hydrogen generating substance 604 that generates hydrogen can be stored. However, a material and shape that do not allow water or hydrogen to leak are preferable. As a specific material for the container, a material that is difficult to permeate water and hydrogen and that does not break even when heated to about 120 ° C. is preferable. For example, a metal such as aluminum or iron, a resin such as polyethylene or polypropylene is used. Can be used. Further, as the shape of the container, a prismatic shape, a cylindrical shape or the like can be adopted.

  There is no restriction | limiting in particular about the water storage container 601, For example, the tank etc. which accommodate the water similar to what is used for the conventional hydrogen production apparatus are employable.

  The hydrogen generating substance storage container 603 and the water storage container 601 may be detachable. As a result, when the hydrogen generating material 604 in the hydrogen generating material storage container 603 is completely consumed or when the water 602 in the water storage container 601 is exhausted, these are removed, and a predetermined amount of the hydrogen generating material 604 is filled. Hydrogen can be produced again by newly attaching the hydrogen generating substance storage container 603 and the water storage container 601 filled with a predetermined amount of water 602.

  The water stored in the water storage container 601 may be a liquid containing at least water, such as neutral water, an acidic aqueous solution, or an alkaline aqueous solution, and a suitable one is selected according to the reactivity with the hydrogen generating material used. do it.

  Although there is no restriction | limiting in particular as the hydrogen generating substance 604 accommodated in the hydrogen generating substance storage container 603, The thing which can generate hydrogen by reacting at a low temperature of 120 degrees C or less with water is desirable. As the hydrogen generating substance, for example, a metal such as aluminum, silicon, zinc, and magnesium, an alloy mainly composed of one or more elements of aluminum, silicon, zinc, and magnesium, and a metal hydride are preferable. Can be used. When the above alloy is used, metal components other than the main element are not particularly limited. The main element means an element contained in an amount of 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more based on the entire alloy.

  The hydrogen generating material composed of the above metal or alloy is stabilized by forming an oxide film on the surface. For this reason, in order to increase the reactivity, it is preferable to make the particle size of the hydrogen generating material as small as possible and increase the reaction area. For example, the average particle diameter of the hydrogen generating substance particles is preferably 100 μm or less, and more preferably 50 μm or less. The particle shape is preferably flakes in order to increase reaction efficiency. If the particle size is too small, the bulk density is reduced, the packing density is lowered, and handling becomes difficult. Therefore, the particle size of the hydrogen generating material is preferably 0.1 μm or more.

  As a method for measuring the average particle diameter, for example, a laser diffraction / scattering method or the like can be used. Specifically, this is a particle diameter distribution measurement method using a scattering intensity distribution detected by irradiating a measurement target substance dispersed in a liquid phase such as water with laser light. As a particle size distribution measuring apparatus using a laser diffraction / scattering method, for example, “Microtrack HRA” manufactured by Nikkiso Co., Ltd. can be used.

  Examples of the metal hydride that can be used as the hydrogen generating substance include sodium borohydride and potassium borohydride. These metal hydrides are relatively stable in an aqueous alkali solution, but when a catalyst is present, they can rapidly react with water to generate hydrogen. As the catalyst, for example, metals such as Pt and Ni, acids, and the like can be used.

  As the hydrogen generating substance, those exemplified above may be used alone or in combination of two or more.

  In addition, the hydrogen generating material may be heated in a state of being mixed with water or supplied with heated water in order to increase the reactivity with water.

  Furthermore, by using the hydrogen generating material together with a heat generating material that generates heat by reacting with water (a material other than the hydrogen generating material), the heat generation of the heat generating material can be achieved even when low temperature water (for example, about 5 ° C.) is supplied. As a result, the temperature in the reaction system is increased, and rapid hydrogen generation becomes possible.

  Examples of the exothermic substance that reacts with water and generates heat include, for example, calcium oxide, magnesium oxide, calcium chloride, magnesium chloride, calcium sulfate, or the like, which becomes a hydroxide by reaction with water, or generates heat by hydration. And alkali metal or alkaline earth metal oxides, chlorides, sulfuric acid compounds and the like. In addition, those that generate hydrogen by reaction with water, such as metal hydrides such as sodium borohydride, potassium borohydride, and lithium hydride, can be used as a hydrogen generating substance as described above. However, it can also be used as a heat generating material when the above metal or alloy is used as a hydrogen generating material.

  In particular, when a metal such as aluminum, silicon, zinc, or magnesium or an alloy mainly composed of one or more elements selected from aluminum, silicon, zinc, and magnesium is used as the hydrogen generating substance, the above exothermic substance is used. It is preferable to use together. On the other hand, when the above metal hydride is used as the hydrogen generating material, hydrogen can be produced at a relatively good rate without using the above exothermic material. May be increased.

  The gas-liquid separation container 800 includes an introduction pipe 801 for introducing a gas-liquid mixed fluid, two drainage pipes 803 and 804 for discharging a liquid separated from the gas-liquid mixed fluid, and a gas separated from the gas-liquid mixed fluid It is a hemispherical container having an exhaust pipe 802. In the present embodiment, by providing the gas-liquid separation container 800, the amount of liquid components in the gas containing hydrogen supplied to the fuel cell 100 can be reduced, and thereby the fuel cell by supplying moisture. 100 troubles can be prevented. In FIG. 11, the drain pipe 804 is connected to the water container 601 via a pipe 510, and the drain pipe 803 is connected to the water container 601 via a pipe 511, a three-way valve 401, a pump 201, and a pipe 501. Has been. The introduction pipe 801 is connected to the hydrogen generating substance storage container 603 via the pipe 503. The exhaust pipe 802 is connected to the fuel cell 100 via a pipe 504, a three-way valve 402, and a pipe 505.

  The gas-liquid separation container 800 is not particularly limited as long as it is made of an inflexible material that has excellent heat resistance and corrosion resistance and does not deform the container. A structure that can withstand fluctuations in internal pressure such as pressure is more preferable. As a specific material of the container, a material that does not easily transmit water and hydrogen and that does not break even when heated to about 120 ° C. is preferable. For example, a metal such as aluminum or iron, an acrylic resin, a hard polypropylene, Resins such as polyethylene can be used. In addition, the shape of the container is hemispherical here, but other shapes such as a prismatic shape, a cylindrical shape, and a spherical shape can be adopted.

  Here, the detailed structure of the gas-liquid separation container 800 of this embodiment is demonstrated using FIG. FIG. 12 is a schematic perspective view showing the inside of the gas-liquid separation container 800 in the present embodiment.

  In FIG. 12, drainage pipes 803 and 804 are disposed on the upper surface of the gas-liquid separation container 800 and extend from the inside of the gas-liquid separation container 800 to the outside. The drainage pipes 803 and 804 have a first opening (not labeled) on the inside of the gas-liquid separation container 800 and discharge the liquid from the inside of the gas-liquid separation container 800 to the outside. Each of the first openings of the drainage pipes 803 and 804 is connected to the end of a flexible water absorption pipe 805, and a weight 806 is provided at the tip of the water absorption pipe 805. The water absorption pipe 805 is bent by the action of the weight 806, and the water suction port 809 of the water absorption pipe 805 moves in the gravity direction in the gas-liquid separation container 800, so that the gas-liquid separation is performed regardless of the direction in which the gas-liquid separation container 800 is inclined. It will be in the state which can contact with the liquid stored in the container 800. FIG. Thereby, irrespective of the inclination of the gas-liquid separation container 800, the liquid stored in the gas-liquid separation container 800 can be sucked and discharged.

  Further, the two water absorption pipes 805 are fixed by a fixing band 810 so as not to be entangled with each other. Thereby, the angle at which the water absorption pipe 805 bends is limited, and the entanglement between the water absorption pipes 805 and the entanglement between the water absorption pipe 805 and the drainage pipes 803 and 804 or the intake pipe 807 can be suppressed. In addition, the effect which suppresses the said entanglement is not limited to the fixed band 810, It can obtain also by the other mechanism which connects the some water absorption pipe | tube 805. FIG. For example, if the weight 806 also serves to fix the plurality of water absorption pipes 805, the installation of the fixing band 810 can be omitted, and problems such as the fixing band 810 coming off can be avoided.

  The introduction pipe 801 is disposed on the upper surface of the gas-liquid separation container 800 and extends from the inside of the gas-liquid separation container 800 to the outside. The introduction pipe 801 has a second opening (not labeled) on the inside of the gas-liquid separation container 800 and introduces the gas-liquid mixed fluid from the outside to the inside of the gas-liquid separation container 800.

  The exhaust pipe 802 is disposed on the upper surface of the gas-liquid separation container 800 and extends from the inside of the gas-liquid separation container 800 to the outside. The exhaust pipe 802 has a third opening (not labeled) on the inner side of the gas-liquid separation container 800, and discharges gas from the gas-liquid separation container 800 to the outside. The end of the intake pipe 807 is connected to the third opening of the exhaust pipe 802, and the tip of the intake pipe 807 is disposed at the center of the gas-liquid separation container 800. A gas in the gas-liquid separation container 800 is sucked from an intake port 808 and transported into the exhaust pipe 802. As a result, as long as the liquid level of the liquid stored in the gas-liquid separation container 800 does not reach the intake port 808, the intake port 808 is in the gas-liquid separation container 800 no matter what direction the gas-liquid separation container 800 is inclined. It is possible to avoid contact with the liquid inside, and to prevent the liquid from entering the exhaust pipe 802. In FIG. 12, the exhaust pipe 802 and the intake pipe 807 are integrally formed so as to be indistinguishable.

  The drainage pipes 803 and 804, the introduction pipe 801 and the exhaust pipe 802 are not particularly limited as long as they have excellent heat resistance, chemical resistance and strength. For example, PTFE, hard silicon, polyetheretherketone, polyphenylene Metal pipes such as resin tubes such as sulfide, polycarbonate, ethylene tetrafluoride, and polysulfone, and stainless steel pipes are preferably used.

  The water absorption pipe 805 is not particularly limited as long as it is hollow and flexible, but a Freon tube excellent in heat resistance and chemical resistance, and a silicon tube are preferably used.

  The weight 806 is not particularly limited as long as it has excellent chemical resistance, but, for example, a plated lead or stainless steel is preferably used. Further, the weight of the weight 806 is not particularly limited as long as the weight of the liquid to be collected is, for example, water, which is greater than the specific gravity (d = 1.0) and larger than the weight obtained by subtracting the buoyancy of the water absorption pipe 805. However, the specific gravity (d ≧ 10) or more is preferable from the responsiveness of the weight. The size of the weight 806 is not particularly problematic as long as it does not hit the wall surface or piping in order to ensure directionality, but it may be less than 10% of the total volume of the gas-liquid separation container 800. preferable.

  The intake pipe 807 is not particularly limited as long as it has excellent heat resistance and chemical resistance, but a PTFE tube, a hard silicon tube, or the like is preferably used. The shape of the intake pipe 807 is not particularly limited as long as the intake port 808 can be arranged at the center of the gas-liquid separation container 800, but the intake pipe 807 may be arranged so as not to be entangled with the water absorption pipe 805 moving in all directions by the weight 806. More preferred.

  The fixing band 810 is not particularly limited as long as it is difficult to corrode, but for example, the same material as the container can be used.

  When the gas-liquid mixed fluid is introduced into the gas-liquid separation container 800 having such a configuration, the liquid in the gas-liquid mixed fluid is discharged in the direction of the drainage pipes 803 and 804, and the gas in the gas-liquid mixed fluid is discharged. Is discharged in the direction of the exhaust pipe 802. For example, when the gas-liquid mixed fluid contains water and hydrogen, the water in the gas-liquid mixed fluid introduced into the gas-liquid separation container 800 from the introduction pipe 801 is inclined in any direction. Even in such a case, the gas-liquid separation container 800 accumulates downward in the direction of gravity. The stored water is sucked in from the water suction port 809 of the water suction pipe 805 bent in the direction of gravity by the action of the weight 806, and discharged through the water suction pipe 805 in the drainage pipes 803 and 804. The power source of the drainage at this time is, for example, when the liquid is sent via the pump on the flow path of the drain pipes 803 and 804, or by the action of the pump that feeds the water from the water container to the hydrogen generating substance container. The liquid can be drained outside the gas-liquid separation container 800. On the other hand, hydrogen in the gas-liquid mixed fluid is sucked from an intake port 808 installed at the center of the gas-liquid separation container 800, and discharged through the intake pipe 807 toward the exhaust pipe 802. This discharged hydrogen can be used as a hydrogen source of the fuel cell.

  The description of the gas-liquid separation container 800 with reference to FIG. 12 has been completed, and the operation of the hydrogen production apparatus according to the present embodiment will be described with reference to FIG.

  The water 602 stored in the water storage container 601 is transported to the hydrogen generating substance storage container 603 through the pipe 501 and the pipe 502 by driving the pump 201. In the hydrogen generating substance storage container 603, the hydrogen generating substance 604 and the water 602 react to generate hydrogen, and this hydrogen is discharged to the pipe 503. When steam is discharged together with hydrogen into the pipe 503, the steam is cooled in the pipe 503 to become water, and a gas-liquid mixed fluid of water and hydrogen is introduced into the introduction pipe 801 of the gas-liquid separation container 800. . In the gas-liquid separation container 800, the gas-liquid mixed fluid is separated into a gas containing hydrogen and water due to a difference in gravity.

  The separated gas containing hydrogen is supplied to the fuel cell 100 through the exhaust pipe 802 and the pipes 504 and 505. Since the gas-liquid separation container 800 has directionality as described above, gas-liquid separation can be performed regardless of the direction of the hydrogen production apparatus, and hydrogen can be stably supplied to the fuel cell 100. In addition, it is possible to avoid the occurrence of problems in the fuel cell 100 due to the supply of moisture.

  On the other hand, the separated water is collected in the water storage container 601 as described below and reused as the water 602 supplied to the hydrogen generating substance storage container 603. Thereby, the utilization efficiency of water can be improved. Furthermore, since the water storage container 601 that stores water for hydrogen production is also used as a recovery container, there is no need to separately provide a recovery container for recovering the water separated in the gas-liquid separation container 800. The whole can be made compact.

  Next, a mechanism for collecting the water separated in the gas-liquid separation container 800 in the water storage container 601 will be described in detail.

  While the water 602 in the water storage container 601 is being supplied to the hydrogen generating substance storage container 603 at a constant rate using the pump 201, the internal pressure of the water storage container 601 is in a reduced pressure state. In order to compensate for this reduced pressure state, in another pipe 510 connected to the water container 601, a suction force is generated in the direction from the drainage pipe 804 side of the gas-liquid separation container 800 to the water container 601 side. By utilizing this phenomenon, the stored water in the gas-liquid separation container 800 can be recovered in the water storage container 601. Therefore, it is not necessary to separately provide a pump for transporting the water in the gas-liquid separation container 800 to the water storage container 601 in the middle of the pipe 510, and power saving can be achieved.

  On the other hand, when it is not necessary to produce hydrogen, such as at the end of power generation of the fuel cell 100, the drive of the pump 201 is stopped and the water supply to the hydrogen generating substance storage container 603 is stopped. For a while, the water 602 remaining in the hydrogen generating substance storage container 603 reacts with the hydrogen generating substance 604 to generate hydrogen, and as a result, water is generated, and this water is stored in the gas-liquid separation container 800. Therefore, it is necessary to collect water from the gas-liquid separation container 800 for a certain time after the water supply is stopped. Therefore, in the present embodiment, the three-way valve 401 is switched to the direction in which the pipe 511 and the pipe 501 communicate, and the pump 201 is operated in the direction opposite to the direction in which the liquid is transferred from the water storage container 601 to the hydrogen generating substance storage container 603. Thus, the water accumulated in the gas-liquid separation container 800 is collected in the water storage container 601 through the pipe 511, the three-way valve 401, and the pipe 501. Furthermore, since the gas (air) corresponding to the volume of the water collected in the water storage container 601 is sent from the water storage container 601 to the fuel cell 100 via the pipe 510, the gas-liquid separation container 800, the pipes 504, 505, Since the internal pressures of the water storage container 601 and the gas-liquid separation container 800 do not increase, it is safe.

<Exhaust means>
As described above, the exhaust means in the present embodiment is for exhausting the fuel gas in the fuel cell 100 out of the system. In FIG. 11, the exhaust means includes pipes 506, 507, 508, 509, pressure sensor 300, valve 402, valve 403, check valve 700, and hydrogen for consuming hydrogen in the gas discharged from the fuel cell 100. The consumer device 900 is configured.

  The valve 403 is for intermittently discharging the fuel gas in the fuel cell 100 to the outside of the fuel cell 100. In the fuel cell power generation system of the present embodiment shown in FIG. 11, as the fuel cell 100 generates power, fuel gas (residual hydrogen not involved in power generation and the positive electrode side during power generation) appears on the negative electrode side of the fuel cell 100. Gas and a small amount of generated water accumulate, and when the pressure in the fuel cell 100 increases to some extent by these, the above-mentioned gas and a small amount of generated water are piped 507 using the valve 403. To the side. As described above, the gas and generated water in the fuel cell 100 can be intermittently discharged out of the fuel cell 100 by the action of the valve 403.

  The pressure sensor 300 measures the pressure in the pipe 505. By controlling the opening and closing operation of the valve 403 in a timely manner based on the measurement result of the pressure sensor 300, the gas and generated water in the fuel cell 100 can be discharged to the pipe 507 side. The valve 403 is desirably controlled to perform an opening / closing operation when the pressure difference between the negative electrode pressure in the fuel cell 100 and an external pressure (for example, atmospheric pressure) reaches 1 to 300 kPa. When the differential pressure is opened at less than 1 kPa, the pressure difference is too small and the ability to discharge water is reduced. When the differential pressure is not opened until the pressure exceeds 300 kPa, the internal pressure becomes too high and the MEA may be damaged. . Further, when the valve 403 is in the appropriate pressure range, the valve 403 can be opened and closed at regular intervals. When the fuel cell 100 is opened and closed at regular intervals, it is possible to forcibly discharge generated water generated during power generation of the fuel cell 100 to the outside.

  In this way, by controlling the opening / closing operation of the valve 403 while measuring the pressure of the fuel cell using the pressure sensor 300, the pressure of the fuel cell becomes too high and hydrogen leaks from the fuel cell. Rupture can be suppressed and power can be generated appropriately. In addition, it is possible to generate power so that the output can be properly maintained in consideration of the output state of the fuel cell and the pressure information.

  The hydrogen consuming apparatus 900 consumes hydrogen contained in the gas discharged from the fuel cell 100 and the gas after moisture is removed in the gas-liquid separation container 800. In the system shown in FIG. 11, the gas discharged from the fuel cell 100 is introduced into the hydrogen consuming apparatus 900 through the pipe 507, and the gas after the moisture is removed in the gas-liquid separation container 800 is piped as described later. It is introduced into the hydrogen consuming apparatus 900 through 506. A hydrogen consuming apparatus 900 in FIG. 11 has an MEA (not shown), and consumes hydrogen in the gas by the same mechanism as the power generation by the MEA of the fuel cell 100. The gas from which hydrogen has been removed by the hydrogen consuming apparatus 900 is discharged out of the system via the pipe 509. In the system shown in FIG. 11, the outlet of the pipe 509 is arranged so as to receive air from the discharge air supply unit 90, so that the hydrogen consuming apparatus 900 cannot process the hydrogen and a little hydrogen remains. However, it can be discharged out of the system while being diluted.

  Further, a water transpiration device (not shown) may be installed after the hydrogen consuming device 900. A small amount of generated water generated by the power generation of the fuel cell 100 or water that could not be separated in the gas-liquid separation container 800 is introduced into the fuel cell 100, and is controlled to the outside of the fuel cell 100 by the control of the pressure sensor 300 and the valve 403. The discharged water is introduced into the hydrogen consuming apparatus 900 through the pipe 507, and the water remaining after the removal of hydrogen is supplied to the water transpiration apparatus. By installing this water transpiration device, it is possible to suppress discharge of water to the outside of the fuel cell power generation system. Moreover, this water transpiration apparatus can also serve as the hydrogen consumption apparatus 900.

  By the way, in general, in a fuel cell, when power generation is stopped, if the state where air is stored in the positive electrode and hydrogen is stored in the negative electrode in the fuel cell continues for a long time, the electrode deteriorates. The cause of this is not clear, but in this case, since the voltage is maintained in a higher state than during power generation, it is presumed that the positive and negative carbon and catalyst are oxidized. Therefore, the fuel cell power generation system may be configured to prevent hydrogen from entering the fuel cell at the end of power generation or may be configured to remove hydrogen remaining in the fuel cell. preferable.

  In the system shown in FIG. 11, a valve 402 is provided between a pipe 504 and a pipe 505 for introducing hydrogen from the hydrogen production apparatus 600 into the fuel cell. The valve 402 is connected to the hydrogen consuming apparatus 900 via a pipe 506. Therefore, when the power generation of the fuel cell 100 is completed, the valve 402 is operated to supply the hydrogen from the hydrogen production device 600 directly to the hydrogen consuming device 900 through the pipe 506 without being sent to the fuel cell 100 for processing. it can. At the same time, the valve 403 can be switched in a direction in which the pipe 507 and the check valve 700 communicate with each other. This consumes the remaining hydrogen in the fuel cell 100, so that the remaining hydrogen can be consumed by short-circuiting the positive and negative electrodes of the fuel cell 100. In this case, the inside of the fuel cell 100 may be depressurized and the MEA may be damaged. For this reason, the internal pressure of the fuel cell 100 can be prevented from being lowered by switching the valve 403 in a direction in which the pipe 507 and the check valve 700 communicate with each other and taking in outside air. With these operations, the system shown in FIG. 11 can prevent hydrogen from entering the fuel cell 100 at the end of power generation by the fuel cell 100 and suppress deterioration of the fuel cell 100 due to such hydrogen.

  The hydrogen consuming apparatus according to the fuel cell power generation system of the present embodiment is not particularly limited as long as it can consume and remove hydrogen in the system. For example, the hydrogen consuming apparatus has an MEA and generates power by the MEA according to the fuel cell. Examples thereof include an apparatus that consumes hydrogen by the same mechanism, and an apparatus that has a catalyst capable of oxidizing hydrogen.

  As an apparatus for consuming hydrogen by the same mechanism as the power generation by the MEA related to the fuel cell, specifically, like the MEA constituting the fuel cell shown in FIGS. 4 and 5, a positive electrode diffusion layer, a positive electrode catalyst layer, Hydrogen consumption having MEA having a configuration in which a solid polymer electrolyte membrane, a negative electrode catalyst layer, and a negative electrode diffusion layer are sequentially laminated, and the positive electrode and the negative electrode are connected so as to be able to conduct through, for example, a switch and a resistor Apparatus.

  Regarding the positive electrode diffusion layer, the positive electrode catalyst layer, the solid polymer electrolyte membrane, the negative electrode catalyst layer, and the negative electrode diffusion layer according to the MEA of the hydrogen consuming apparatus, the positive electrode diffusion layer, the positive electrode catalyst layer, and the solid polymer electrolyte membrane according to the MEA of the fuel cell As the negative electrode catalyst layer and the negative electrode diffusion layer, the same ones as described above can be used.

  In the case of the hydrogen consuming apparatus described above, when it is necessary to consume hydrogen in the gas, a switch is made at the connection between the positive electrode and the negative electrode, and conduction between the positive electrode and the negative electrode of the MEA is performed. Can be consumed. As a result, hydrogen in the gas that needs to be exhausted from inside the fuel cell and needs to be discharged outside the system, and hydrogen that enters the fuel cell from the hydrogen production device at the end of power generation by the fuel cell are completely eliminated. Alternatively, the amount of hydrogen can be greatly reduced.

  In the hydrogen consuming apparatus having the above MEA, when the positive electrode and the negative electrode of the MEA are connected via a resistor, the resistance is, for example, between the positive electrode and the negative electrode of the MEA after hydrogen is introduced into the hydrogen consuming device. It is sufficient to use a resistor having such a resistance value that the time required for the voltage to be 0.1 V or less is within one minute. Moreover, if the voltage between the positive electrode and the negative electrode of the MEA can be lowered as described above without using a resistor, the positive electrode and the negative electrode of the MEA are only switches without using a resistor. It may be possible to conduct by connecting with a lead body or the like via

  As described above, since the hydrogen consuming apparatus includes the MEA similarly to the fuel cell, for example, a fuel cell having a plurality of MEAs (stack) is used, and a part of the MEAs (for example, one, The fuel cell and the hydrogen consuming device may be integrated (not shown) in a form in which two, three, etc.) are used as the hydrogen consuming device.

  Examples of the hydrogen consuming apparatus having a catalyst that can oxidize hydrogen include a filter containing the catalyst, a cylinder-shaped exterior body filled with the catalyst, and the like. In addition, as a catalyst which can oxidize hydrogen, the various catalysts previously illustrated as a catalyst in the negative electrode catalyst layer of MEA can be used, for example.

  The air supply directions of the supply air supply unit 91 and the discharge air supply unit 90 can be changed as appropriate depending on the ambient temperature at which the fuel cell system is operated. The fuel cell 100 needs to be installed in a system casing together with auxiliary devices and circuits for control. In addition, auxiliary equipment and circuits inside the housing may generate heat as the power generation is controlled. In order to efficiently generate power in the fuel cell 100, a range of 5 ° C. or higher and 50 ° C. or lower is preferable. If it is less than 5 ° C., the power generation efficiency of the fuel cell 100 is lowered, and the water remaining in the fuel cell 100 may be frozen. On the other hand, when the temperature greatly exceeds 50 ° C., the water in the fuel cell 100 tends to evaporate, and the power generation efficiency may be reduced.

  For this reason, when the environment in which the fuel cell power generation system is operated is at a low temperature (for example, around 0 ° C.), the oxidant gas (for example, air) generated by the auxiliary equipment and the circuit inside the housing is stably used. It can generate electricity. For this reason, it is preferable that the supply air supply unit 91 and the discharge air supply unit 90 supply gas in the direction in which the gas that has passed through the auxiliary devices and circuits inside the housing is supplied to the fuel cell 100. On the other hand, when the environmental temperature is high (for example, around 60 ° C.), the temperature of the oxidant gas (for example, air) supplied to the fuel cell 100 is set in the direction in which outside air is taken (for example, from the discharge air supply unit 90). It is preferable to supply air in the direction of the supply air supply unit 91).

  In the first to third embodiments, the fuel cell system of the present invention and the fuel cell power generation system using the fuel cell system of the present invention have been described with reference to FIGS. 1 to 12. However, FIGS. The fuel cell, the fuel cell system, and the fuel cell power generation system shown in FIG. 1 are only some of the components that can be used in the fuel cell system, and the fuel cell power generation system using the fuel cell system of the present invention. Is not limited to those shown in these drawings or having the components shown in these drawings.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples do not limit the present invention.

Example 1
<Fabrication of fuel cell>
First, a fuel cell 100 having the same structure as that shown in FIG. 2 was produced.

  As the laminate of the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer, the one shown in FIG. 7 was used. “Nafion (registered trademark) 112” manufactured by DuPont was used as the solid polymer electrolyte membrane. Pt-supported carbon (“TEC10E50E” manufactured by Tanaka Kikinzoku Co., Ltd.) and a 5 mass% Nafion solution (manufactured by Aldrich) were mixed in a predetermined amount, and this was applied to one side of a polytetrafluoroethylene sheet and dried. . A polytetrafluoroethylene sheet is stacked on both sides of the solid polymer electrolyte membrane so that the application surface of the mixture of Pt-supported carbon and Nafion solution is on the solid polymer electrolyte membrane side, and hot pressing is performed. The fluoroethylene sheet was removed to obtain a laminate of the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer. Thereafter, the laminate was cut out so that the outer shape was 24 mm × 85.5 mm.

  “GDL10DC” (thickness: 470 μm) manufactured by SGL Carbon was cut into a size of 24 mm × 71.5 mm and used for the positive electrode diffusion layer. In addition, two 24 mm × 7 mm silicon rubber sheets (thickness 0.3 mm) were prepared for the positive electrode gas seal, and 20 mm × 3 mm holes (fuel supply manifold and fuel discharge manifold) were formed in both.

  For the negative electrode gas seal, the same silicon rubber sheet as the positive electrode gas seal is used, the size is 24 mm × 85.5 mm, and the negative electrode diffusion layer is inserted and the fuel supply manifold and the fuel discharge manifold are configured to be 20 mm × A hole with a size of 81.5 mm was formed. For the negative electrode diffusion layer, the same material as that used for the positive electrode diffusion layer was used, and cut into a size of 20 mm × 75.5 mm.

  Fifteen MEAs were produced by laminating the above laminate, positive electrode diffusion layer, positive electrode gas seal, negative electrode diffusion layer and negative electrode gas seal in the order and arrangement shown in FIG.

  A separator made of carbon (thickest portion has a thickness of 2 mm) and having the configuration shown in FIG. 6 was used. The outer shape was 24 mm × 85.5 mm, and the sizes of the fuel supply manifold 11 and the fuel discharge manifold 12 were 20 mm × 3 mm. The oxidant gas flow path (oxidant gas flow path that also serves as the cooling medium flow path) 13 has a width of 1.5 mm and a depth of 1.5 mm, and the rib 14 between the oxidant gas flow paths 13 has a width of 1 mm. .

  The 15 MEAs are stacked while the separator is interposed between the MEAs so that the oxidant gas flow path forming surface side is on the positive electrode diffusion layer side. Thus, the fuel cell 100 having the structure shown in FIG. 2 was manufactured by sandwiching it with a size of 38 mm × 90 mm) and fixing it with bolts and nuts.

<Production of fuel cell system>
A fuel cell system 101 was produced by installing a supply air supply unit 91 and a discharge air supply unit 90 in the fuel cell 100 as shown in FIGS. A 40 mm square DC fan was used for the supply air supply unit 91 and the discharge air supply unit 90. The supply air supply unit 91 and the discharge air supply unit 90 are fixed at a distance of 0 mm from the end plate 50, and the duct 80 is installed so as to seal the supply port 51 and the exhaust port 52.

<Production of hydrogen production equipment>
A hydrogen production apparatus 600 shown in FIG. 11 was produced. The hydrogen generating substance storage container 603 is a polypropylene prismatic container having an internal volume of 50 cm ³ , in which 20.7 g of aluminum powder (hydrogen generating substance) having an average particle size of 6 μm and calcium oxide (exothermic substance) are used. 3.5 g was added.

<Assembly of fuel cell power generation system>
A fuel cell power generation system shown in FIG. 11 was assembled using the fuel cell system 101, the hydrogen production apparatus 600, the pressure sensor 300 as an exhaust means, the hydrogen consumption apparatus 900, and the check valve 700.

(Comparative Example 1)
In Comparative Example 1, a fuel cell system was manufactured in the same manner as in Example 1 except that the supply air supply portion 91 and the duct 80 were not installed on the supply port 51 side. FIG. 13 shows a schematic configuration of the fuel cell system of Comparative Example 1, and FIG. 14 shows a cross-sectional view taken along the line VI-VI of the fuel cell system shown in FIG. 13 and 14, the same components as those in FIGS. 1 and 3 are denoted by the same reference numerals. In the cross-sectional view of FIG. 14, the oxidant gas flow path is omitted and the discharge air supply unit 90 is simplified. In FIG. 14, hatching is omitted.

  In the fuel cell system of this comparative example, one 40 mm square DC fan was installed as the discharge air supply unit 90. The distance between the end plate 50 and the 40 mm square DC fan was 0 mm, and a duct 80 was installed at the exhaust port 52. Then, using this fuel cell system, a fuel cell power generation system was assembled in the same manner as in Example 1.

<Power generation test>
A power generation test of the fuel cell power generation system of Example 1 and the fuel cell power generation system of Comparative Example 1 was performed. Specifically, water 602 in the water container 601 is supplied to the hydrogen generating substance container 603 to generate hydrogen, and an oxidant gas (air containing oxygen) is sent from the supply port 51 toward the exhaust port 52. The power generation test was conducted at a constant voltage of 9.5 V with an external load (not shown).

  The results of power generation characteristics in the fuel cell power generation systems of Example 1 and Comparative Example 1 are shown in FIG. In FIG. 15, the vertical axis represents output (W) and the horizontal axis represents time (minutes). From FIG. 15, compared with Comparative Example 1 in which the air supply unit is installed only at the exhaust port, the power generation performance is higher in Example 1 in which one air supply unit is installed in each of the supply port and the exhaust port. Was found to be stable over time. Therefore, in order to achieve stable power generation and space saving, it can be said that it is preferable that there are air supply portions at both the supply port and the exhaust port.

  The fuel cell system of the present invention can be preferably used in various applications in which conventional fuel cells are used, including power supply applications for highly functional portable electronic devices such as cordless devices such as personal computers and mobile phones.

10 Separator 11 Fuel supply manifold 12 Fuel discharge manifold 13 Oxidant gas flow path 14 Rib 20 MEA
20a Laminate 21 Positive electrode diffusion layer 22 Positive electrode catalyst layer 23 Solid electrolyte membrane 24 Negative electrode catalyst layer 25 Negative electrode diffusion layer 30 Positive electrode gas seal 40 Negative electrode gas seal 50 End plate 51 Supply port 52 Exhaust port 60 Fuel supply port 70 Fuel discharge port 80 Duct 90 Exhaust air supply part 91 Supply air supply part 100 Fuel cell 101 Fuel cell system 201 Pump 300 Pressure sensor 401, 402, 403 Valve 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511 Piping 600 Hydrogen production apparatus 601 Water container 602 Water 603 Hydrogen generating substance container 604 Hydrogen generating substance 700 Check valve 800 Gas-liquid separation container 801 Inlet pipe 802 Exhaust pipes 803 and 804 Drain pipe 805 Intake pipe 806 Weight 807 Intake Pipe 808 Inlet 809 Inlet 810 Fixed van 900 hydrogen-consuming device

Claims (9)

An electrode / electrolyte integrated product having a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane disposed between the positive electrode and the negative electrode A fuel cell formed by laminating a plurality of separators;
An oxidant gas passage formed on one main surface of the separator and having an oxidant gas supply port and an exhaust port;
An air supply unit for supplying an oxidant gas to the supply port of the oxidant gas flow path;
A fuel cell system comprising: an exhaust air supply section that exhausts the oxidant gas in the oxidant gas flow path to the outside from the discharge port of the oxidant gas flow path.   The fuel cell system according to claim 1, comprising a plurality of the supply air supply unit or the discharge air supply unit.   The fuel cell system according to claim 2, wherein the plurality of supply air supply units or the plurality of discharge air supply units can be controlled.   The fuel cell system according to any one of claims 1 to 3, wherein air volumes of the supply air supply unit and the discharge air supply unit are adjusted so that the temperature of the fuel cell falls within a certain range. The electrode / electrolyte integrated product has a quadrangular shape in plan view,
The separator has a quadrangular shape in plan view, and is composed of a single member,
In the electrode / electrolyte integrated body and the separator, a fuel supply manifold is formed in the vicinity of one of the four sides constituting the quadrangle, and a fuel discharge manifold is formed in the vicinity of the one side facing the one side. Formed,
A plurality of the oxidant gas flow paths are arranged in parallel so as to linearly connect two sides of the main surface of the separator other than the opposed two sides formed in the vicinity of the fuel manifold and the fuel discharge manifold. The fuel cell system according to any one of claims 1 to 4, wherein the fuel cell system is formed substantially in parallel, and both ends thereof are the supply port and the discharge port of the oxidant gas. The negative electrode of the electrode / electrolyte integrated product has a negative electrode diffusion layer disposed so as to be in contact with the surface of the separator where the oxidant gas flow path is not formed,
The negative electrode diffusion layer has a quadrangular shape in plan view, and a negative electrode gas seal for suppressing outflow of fuel gas is formed on the outer periphery of the negative electrode diffusion layer.
A fuel supply manifold is formed by one of the four sides constituting the quadrangle of the negative electrode diffusion layer and the negative electrode gas seal, and one side facing the one side of the negative electrode diffusion layer and the negative electrode gas The fuel cell system according to any one of claims 1 to 5, wherein a fuel discharge manifold is formed by the seal. The positive electrode of the electrode / electrolyte integrated product has a positive electrode diffusion layer disposed so as to be in contact with the surface of the separator where the oxidant gas flow path is formed,
The positive electrode diffusion layer has a quadrangular shape in plan view, and of the four sides constituting the quadrilateral, outside of two sides parallel to or substantially parallel to the oxidant gas flow path of the separator, A positive electrode gas seal for suppressing the outflow is arranged,
The fuel cell system according to any one of claims 1 to 6, wherein a fuel supply manifold and a fuel discharge manifold are formed in the positive electrode gas seal.   The fuel cell system according to any one of claims 1 to 7, wherein the oxidant gas flow path of the separator also serves as a cooling medium flow path.   The fuel cell system according to any one of claims 1 to 8, wherein the positive electrode catalyst layer, the negative electrode catalyst layer, and the solid polymer electrolyte have the same shape in plan view.

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