JP2010192124A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell in which damages in partition portions are reduced and an operation, enabling stable power generation performance. <P>SOLUTION: The fuel cell is provided with a power generating chamber in which a plurality of fuel battery cells 2 are arranged; an upper chamber at the upper part of the power generation chamber; and partition portions 18, 19, 20, 21, 22 to partition the power generation chamber and the upper chamber. By having a plurality of partition portions 18, 19, 20, 21 and 22 provided, damages to the partition portions 18, 19, 20, 21, 22 are reduced, and a fuel cell capable of operation with a stable power generation performance is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell that generates power using city gas or the like to supply power consumed at home, for example, and more particularly to a fuel cell in which a power generation chamber and an upper chamber such as a combustion chamber are partitioned by a partition.

  In this type of fuel cell, a fuel cell assembly is disposed inside a fuel cell container, the fuel cell assembly side is a power generation chamber, and the upper chamber above the fuel cell assembly is a combustion chamber. In this fuel cell assembly, a plurality of fuel cells formed by laminating ceramic materials having different components as an air electrode, an electrolyte, and a fuel electrode are electrically connected to form an assembly.

  The fuel is supplied from a fuel dispersion chamber located below the fuel cell assembly and comes into contact with the fuel electrode which is the outer surface of each fuel cell. On the other hand, air as an oxidant is supplied to the bottom of the fuel cell through an introduction pipe inserted into the fuel cell and comes into contact with the air electrode which is the inner surface of the fuel cell.

  With this configuration, the fuel moves upward while contacting the fuel electrode outside the fuel battery cell, and the air moves upward while contacting the air electrode inside the fuel battery cell. Electrochemical reaction takes place through this, and electricity is generated. Water vapor and unreacted fuel (exhaust fuel) and unreacted air (exhaust air) generated during the power generation enter the combustion chamber and are mixed, and are discharged from the exhaust gas pipe after ignition combustion.

  Conventionally, in a fuel cell having such a configuration, for example, Patent Document 1 discloses a fuel cell in which a partition portion having a ventilation function is attached between a power generation chamber and a combustion chamber to partition the chambers. It is disclosed. This partition is made of ceramic fiber material, and it is very difficult to manage the flow of exhaust fuel and exhaust air at the boundary between the partition and the fuel cell and between the partition and the fuel cell container. It is important to power generation performance.

  Patent Document 2 discloses a fuel cell in which a porous member made of ceramic is covered with a dense ceramic and used as a partition.

  On the other hand, the assembly operation of the fuel cell is performed at room temperature, but the operating temperature is raised from 700 ° C. to 1000 ° C. during power generation. In this temperature rising process, the partition receives tensile force from the fuel cell container and the fuel cell due to the difference in the linear expansion coefficient between the partition and the fuel cell container and between the partition and the fuel cell.

JP 2004-119297 A (paragraphs 0015 and 0016, FIG. 1) Japanese Patent No. 3686781 (paragraphs 0021 to 0023 FIG. 1)

  In the fuel cells disclosed in Patent Documents 1 and 2 above, since one partition portion having a ventilation function is attached between the power generation chamber and the combustion chamber, the number of fuel cells is particularly small, and the fuel cell container However, when the power generation capacity is small, the partition portion can follow the change in the relative positional relationship between the fuel cell container and the fuel cell due to the thermal expansion of the fuel cell container and the fuel cell, so that no particular problem occurs.

  However, in the case of a commercial fuel cell in which the generated power exceeds 1 KW, for example, the number of fuel cells increases, and the size of the fuel cell container increases and the power generation capacity increases. As the power generation capacity increases due to the increase in the size of the fuel cell, the relative positional relationship between the container and the fuel cell increases greatly due to deformation due to thermal expansion of the fuel cell container. As a result, the partition portion receives a pulling force from the fuel cell container and the fuel cell, and cannot absorb this due to its own deformation, and the peripheral mounting portion with respect to the fuel cell container is peeled off or torn and damaged. There is a fear.

  When the vicinity of the attachment portion of the partition portion of the fuel cell container is broken in this way, the ventilation resistance from the power generation chamber to the combustion chamber is extremely reduced at the damaged portion, and the fuel flows from the power generation chamber to the combustion chamber and burns. The combustion balance in the combustion chamber is lost. Further, the fuel does not flow uniformly from the power generation chamber to the combustion chamber, and the fuel distribution in the power generation chamber is also biased, resulting in a decrease in power generation performance.

  In addition, exhaust air and exhaust fuel enter the power generation chamber from the combustion chamber through the damaged portion of the partition, and combustion occurs in the power generation chamber. This combustion locally raises the temperature of the power generation chamber, causing the fuel electrode to peel off and possibly damaging the fuel cell itself.

  An object of the present invention is to provide a fuel cell capable of reducing damage to a partition portion and capable of operating with stable power generation performance.

In order to solve the above-described problems, a fuel cell according to the present invention includes:
A fuel cell comprising: a power generation chamber in which a plurality of fuel battery cells are disposed; an upper chamber in the upper part of the power generation chamber; and a partition portion that partitions the power generation chamber and the upper chamber. It is characterized by having prepared.

  ADVANTAGE OF THE INVENTION According to this invention, the damage of a partition part can be reduced and the fuel cell which can be drive | operated with the stable electric power generation performance can be provided.

1 is a perspective view showing a fuel cell according to an embodiment of the present invention. FIG. 2 is a longitudinally enlarged sectional view taken along line II-II in FIG. 1. It is a top view of a partition base structure. It is a top view which shows the modification of the partition base structure shown in FIG.

  Prior to describing the best mode for carrying out the present invention, the operation and effect of the present invention will be described.

  A fuel cell according to the present invention is a fuel cell comprising a power generation chamber in which a plurality of fuel cells are arranged, an upper chamber in the upper part of the power generation chamber, and a partition that partitions the power generation chamber and the upper chamber. A plurality of the partition portions are provided.

  According to the fuel cell of the present invention, it is possible to solve all the problems that occur in the partition portion provided in the fuel cell that is an enlarged fuel cell and that includes a plurality of fuel cells. Specifically, it is as follows.

  According to the present invention, since the plurality of partition portions that separate the power generation chamber and the upper chamber above the power generation chamber are provided separately and independently, deformation due to thermal expansion of the fuel cell container occurs between the fuel cell container and the fuel cell. The pulling force acting on the partition portion based on the change in the relative position is not dispersed locally and does not increase locally. That is, even if the size of the fuel cell is increased, the tensile force acting on each partition, particularly the tensile force generated at the connection with the inner edge of the fuel cell container opening around the partition can be kept small. Damage can be suppressed.

  As a result, it is possible to prevent an unexpected flow of fuel from the power generation chamber to the combustion chamber due to damage to the partition portion, so that the fuel bias in the power generation chamber can be reduced and the combustion state distribution in the combustion chamber can be made uniform. It is possible to ensure stable power generation performance. Further, the flow of exhaust fuel and exhaust air into the power generation chamber is also suppressed, so that combustion does not occur in the power generation chamber and the fuel cell is not adversely affected. For this reason, the combustion balance is not disturbed in the combustion chamber, and the fuel is uniformly dispersed in the power generation chamber, so that the power generation efficiency is improved as a whole.

  In particular, in the case of a commercial fuel cell in which the generated electric power exceeds 1 KW, for example, unlike the conventional fuel cell, it is possible to suppress the peripheral mounting portion of the partition portion with respect to the fuel cell container from being peeled off or torn.

  In the fuel cell according to the present invention, it is preferable that the plurality of partition portions be arranged at the same height.

  Thus, by arranging a plurality of partition parts at the same height, the assembly of the partition parts becomes easy, and the flow of unreacted fuel and air that moves from the power generation chamber to the combustion chambers between each partition part. As a result, there is no need to create an unnecessarily disturbing step, and as a result, the exhaust air and the exhaust fuel flow into the combustion chamber uniformly and smoothly.

  Further, the tensile force acting on each partition due to the thermal expansion of the fuel cell container does not increase locally but acts equally on each partition, so that the breakage of the partition is further suppressed and the thermal expansion of the fuel cell container Even if the relative position of the fixed part of the partition part of the container and the restraint part of the partition part by the fuel cell changes, each partition part is not damaged by receiving a large pulling force as in the prior art, and the fuel cell container The fuel and air balance between the fuel cells can be maintained.

  In addition, the fuel cell according to the present invention preferably includes a first placement portion for placing a partition portion on the inner edge of the fuel cell container in which the power generation chamber is formed, and is separate from the first placement portion. The 2nd mounting part which mounts a partition part inside it is good to have.

  Thus, by mounting the partition portion on the first and second mounting portions, the attachment of the partition portion to the fuel cell container becomes strong, and the fixing portion of the partition portion of this container due to the thermal expansion of the fuel cell container The partition part is not damaged even if it receives a tensile force due to the change in the relative position between the fuel cell and the restraint part of the partition part by the fuel cell, and the balance of fuel and air between the fuel cell container and the fuel cell can be maintained. it can.

  Hereinafter, a fuel cell according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a fuel cell according to an embodiment of the present invention. In particular, FIG. 1 shows a power generation unit, and an upper chamber as a combustion chamber, for example, is formed in the upper part of the power generation unit, but is not shown in FIG.

  As shown in the figure, a fuel cell 1 according to an embodiment of the present invention accommodates a cell unit (cell assembly) 10 in which a plurality of fuel cells 2 are electrically and structurally connected, and a cell unit 10. And a fuel cell container 50 having a cell unit insertion opening, and an anode-side electric extraction part 71 and a cathode-side electric extraction part 72 that extract electricity generated by the cell unit 10 to the outside of the fuel cell container 50. Yes.

  Hereinafter, each of these components will be described in detail. A fuel cell container 50 shown in FIG. 1 is made by welding and joining each edge of four side plates made of ferritic stainless steel and one bottom plate made of ferritic stainless steel. Has a box shape opened as the cell unit insertion opening 51. The ribs 52 formed on each side plate serve to prevent deformation of the fuel cell container 50 due to thermal stress generated when the fuel cell is operated.

  Rod insertion portions 61 and 62 are formed in parallel and projecting at predetermined intervals below the upper side plate on the near side in FIG. 1, and anode side electric extraction portion 71 and cathode side electric extraction portion are formed on the rod insertion portions 61 and 62, respectively. 72 is inserted and accommodated.

  The periphery of the four side plates is covered with a silica-based heat insulating material 40, a part of which is shown in FIG. Although not shown in detail here, a fuel dispersion chamber for filling the fuel is formed between the lower end of the cell unit of the fuel cell container 50 and the bottom plate, and the fuel is supplied. This fuel is a hydrogen-rich reformed gas obtained by reforming city gas or the like.

  A dispersion plate (not shown) is placed on the upper surface of the fuel dispersion chamber. A large fuel supply hole is formed in the dispersion plate at a position corresponding to a gap between adjacent fuel cells of the cell unit 10 inserted and accommodated in the fuel cell container 50, and a small size is formed in other portions. A fuel supply hole is formed. The fuel is efficiently supplied to the gaps between adjacent fuel cells of the cell unit 10 through these fuel supply holes.

  In addition, in each cell unit 10, a total of 18 elongated fuel cells 2, 3 × 6, are arranged in a matrix in an end view, and are held in a frame so that the fuel cells are electrically connected to each other. In addition, one cell unit 10 is structurally configured.

  These fuel cells 2 are electrically connected in series with each other, one electrode is electrically connected from a predetermined location of the cell unit 10 to a connection plate on one unit current collector plate, and the other electrode is a cell. The unit 10 is electrically connected to a connection plate on the other unit current collector plate from a predetermined location.

  Although not shown in detail here, the frame includes a holding plate for bundling and fixing both ends of each fuel cell in a matrix in an end view, and a unit group provided outside a portion extending in the vertical direction of the holding plate. It has an electric plate. The unit current collector plate is arranged outside the portion of the holding plate that extends in the longitudinal direction of the fuel cell and with an insulating material interposed between the unit current collecting plate and the unit current collecting plate. Both end portions of the fuel cell 2 are electrically connected to the unit current collector plate via a connection plate. The unit current collecting plate and the holding plate are electrically connected to each other through an insulating material. In addition, the connection plate made of a conductive member is formed to extend in the longitudinal direction at one end in the width direction of the unit current collector plate, and the cell units 10 are electrically connected in series via the connection plate. It has become.

  The individual fuel cells 2 constituting the cell unit 10 are composed of an elongated bottomed cylindrical air electrode that also serves as a support, an electrolyte that covers the surface of the air electrode, and a fuel electrode that covers the surface of the electrolyte. Has been. The air electrode is made of a material containing strontium (Sr) in an oxide of lanthanum (La) and manganese (Mn), and is made by extrusion molding. Further, the air electrode has an elongated bottomed cylindrical body shape with a thickness of about 2 mm in order to serve as a support body, and its lower end portion is gradually reduced in diameter, and has a bottom portion having a substantially U-shaped end surface.

  An air supply pipe having an outer diameter considerably smaller than the outer diameter of the air electrode is inserted from the upper end opening of the air electrode to the vicinity of the bottom of the air electrode. Thereby, air (oxygen) can be sufficiently supplied into the air electrode.

  The electrolyte is made of scandia-stabilized zirconia (ScSZ), and is formed by dipping (immersing) the outer surface of the air electrode.

  The fuel electrode is made by mixing yttria-stabilized zirconia (YSZ) with metallic nickel (Ni), and is formed by winding and firing a tape-shaped fuel electrode material after forming the electrolyte.

  In addition, an interconnector (not shown) is formed so as to protrude from a substantially central portion in the longitudinal direction of the fuel battery cell 2. The interconnector is made of lanthanum (La) and chromium (Cr) oxide mixed with calcium (Ca), and is electrically connected to the air electrode and not connected to the electrolyte and fuel electrodes. The tip end surface of the fuel cell 2 is electrically connected to the fuel electrode of the adjacent fuel cell 2 via nickel foam. As a result, all the fuel cells 2 in the cell unit are electrically connected in series, and the total amount of power generated by the individual fuel cells 2 is the amount of power generated by the single cell unit.

  In the present embodiment, three cell units 10 are arranged in parallel to form one cell block 100, and a total of four cell blocks 100 are inserted and accommodated in the fuel cell container 50 through the cell unit insertion openings 51. Here, the cell units 10 are electrically connected to each other by connecting the unit current collector plates of the adjacent cell units 10 with a unit connection plate made of a narrow and narrow metal conductor. Are connected in series.

  In addition, by electrically connecting the four cell blocks with a block connection plate (not shown) made of a metal conductor that is wider than the unit connection plate (not shown) and has the same length as the unit connection plate, The cell blocks are electrically connected in series.

  FIG. 2 is an enlarged vertical view taken along the line II-II in FIG. 1, that is, along the direction in which six fuel cells 2 constituting the cell unit 10 are arranged in parallel. In order to facilitate understanding of the invention, FIG. 2 shows a configuration in which the configuration is simplified and three fuel cells are arranged in parallel in one cell unit. A heat insulating material 55 is disposed in an inner middle portion of the frame 60 constituting the power generation chamber, and the fuel cell container 50 in FIG. 2 is divided into two power generation regions 50A and 50B by the heat insulating material 55.

  A partition base column 15 is provided on the inner surface of the frame 60, and a partition base structure that divides the fuel cell unit insertion opening 51 (see FIG. 1) into a plurality of portions on the upper end surface of the partition base column 15. 16 is provided. Then, a separate metal top plate 17 is inserted on the upper surface of the partition base structure 16 and the upper end of the fuel cell 2 is inserted on the upper surface so as to block the plurality of openings partitioned by the partition base structure 16. The fuel cell side wall partitions 18, 19, and 20 made of ceramic fiber are disposed with the upper end of the fuel cell 2 inserted into the hole.

  And the cell opening end surface partition parts 21 and 22 made of ceramic fibers are disposed on the upper surface of the uppermost fuel cell side surface partitioning part 20, and the fiber material scattering prevention plate is disposed on the upper surface of the upper fuel cell opening end surface partitioning part 22. A metal top plate 23 is arranged. A lower end outward flange portion 80 a of the top plate reinforcing member 80 is disposed on the peripheral edge portion of the top plate 23.

  On the other hand, a ceramic fiber gasket 24 and a metal gasket 25 are laminated on the upper surface of the upper end outward flange portion 60a of the frame 60 constituting the power generation chamber. A ceramic fiber cross gasket 26 is disposed so as to cover the upper surface of the flange portion 80 a, and a metal cross gasket 27 is disposed on the top surface of the cross gasket 26. Then, the lower end outward flange 80a of the frame 80 forming the combustion chamber is disposed via the ceramic fiber gasket 28, and the upper end outward flange 60a of the frame 60 constituting the power generation chamber is as described above. Each of the stacked gaskets is pressed to maintain the airtightness (sealability) between the power generation chamber and the combustion chamber.

  A hole 110 for inserting the air introduction tube 3 is formed in the center of the fuel cell 2 in the cell opening end surface partitioning portions 21 and 22 and the top plate 23, and the hole diameter is larger than that of the air introduction tube 3. The gap becomes an exhaust hole for exhaust air. In addition, the fuel cell side wall partitions 18, 19, 20, the fuel cell opening end surface partitions 21, 22 and the top plate 23 are communicated so that the space between the fuel cells 2 and the combustion chamber communicate with each other. An exhaust fuel discharge hole 120 is formed.

  FIG. 3 is a plan view showing an example of the partition base structure 16. The partition base structure 16 includes a rectangular frame 16a attached to the opening end surface of the cell unit insertion opening 51 (see FIG. 1), and a cross-shaped connecting body 16b that connects the sides of the rectangular frame 16a. The cell unit insertion opening 51 is divided into partition parts a to d each having four areas by the structure 16.

  In this way, a rectangular frame body is formed by dividing the cell side partition portions 18, 19, 20, the cell opening end surface partition portions 21, 22, and the top plate 23 so as to cover the cell unit insertion opening 51 divided into four in this way. The partition base structure 16 composed of 16a and the cross-shaped connecting body 16b is assembled separately and independently.

  According to the embodiment of the present invention, the cell unit insertion opening 51 is divided into a plurality by the partition base structure 16, and the separate partition portions a to d are provided so as to cover the divided openings. The tensile force generated in the partition parts a to d due to the relative position between the inner edge of the opening of the fuel cell container 50 and the fuel cell 2 due to the thermal expansion of the fuel cell container is dispersed in each of the plurality of partition parts a to d. It will be subdivided to act. That is, the tensile force acting on each partition part a to d is reduced, and damage to the partition part can be suppressed.

  As a result, unexpected flow of fuel into the combustion chamber due to damage to the partition can be suppressed, and deterioration of power generation performance due to uneven fuel distribution in the power generation chamber due to unexpected flow of fuel can be avoided. can do. Further, exhaust air discharged from the power generation chamber to the fuel chamber and exhaust fuel combusted in the fuel chamber can be prevented from flowing into the power generation chamber again, and combustion is caused by a reaction between the exhaust air and the exhaust fuel in the power generation chamber. Does not occur and the fuel cell is not adversely affected.

  In the fuel cell according to the present invention, the plurality of partition parts a to d are arranged at the same height. Thus, by arranging a plurality of partition portions at the same height, it becomes easy to assemble the partition portions, and without causing a step that simply complicates the structure of the connecting portion between the partition portions. Thus, the fuel cell can be efficiently operated by smoothly moving the air and the fuel. In addition, the tensile force generated in the partition due to the change in the relative position of the fuel cell container and the fuel cell due to the thermal expansion of the fuel cell container acts equally on each partition, and the partition is not damaged. It is further suppressed, and exhaust fuel and exhaust air can be discharged from the fuel cell container into the fuel chamber by a specified amount.

  In addition, the fuel cell according to the present invention is provided with a first placement portion for placing the partition portion on the inner edge of the fuel cell container that forms the power generation chamber, and separately from the first placement portion. The 2nd mounting part which mounts a partition part inside is provided.

  In this way, by placing the partition portion on the first and second placement portions, it is possible to reliably maintain the height of each partition portion in the substantially central portion of the fuel cell container, Attachment of the partition part to the fuel cell container becomes strong. Further, since the partition portion is composed of a plurality of partition portions, the partition portion may be damaged even if it receives a tensile force due to a change in the relative position between the fuel cell container and the fuel cell due to thermal expansion of the fuel cell container. In addition, it is possible to suppress deterioration in power generation performance due to non-uniform fuel distribution in the power generation chamber due to unexpected local flow of fuel from the power generation chamber to the combustion chamber, and from the combustion chamber to the power generation chamber. It is possible to prevent the fuel cell from being damaged due to the combustion of the exhaust fuel in the power generation chamber due to the unexpected inflow of exhaust fuel or exhaust air, and to efficiently generate power over a long period of time.

  In the illustrated example, the rectangular frame 16a of the partition base structure 16 is used as the first mounting portion, and the cross-shaped connecting body 16b that connects the pieces of the rectangular frame 16a is used as the second mounting portion. Although it is a structure, this 2nd mounting part may be a linear connection body which connects the opposing pieces of the rectangular frame 16a. In other words, one or more connecting bodies of the partition base structures may be provided in one of the vertical direction and the horizontal direction in FIG. 3 or at a predetermined interval.

  Further, as shown in FIG. 4, the second mounting portion may be a column 59 provided in the fuel cell container at the center of the rectangular frame 16a, that is, at the intersection of the cross-shaped connecting body 16b in FIG. . In this case, the column body 59 is configured to extend upward from the bottom of the fuel cell container 50, and the partition base mounting portion on the upper end surface of the column body 59 is the same as the first mounting portion of the rectangular frame 16a. It is preferable to be located at a height.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Fuel cell 3 Air introduction pipe 10 Cell unit (cell aggregate)
DESCRIPTION OF SYMBOLS 15 Partition base support | pillar 16 Partition base structure 16a Rectangular frame 16b Cross-shaped connection body 17 Top plate 18, 19, 20 (Fuel cell) Cell side surface partition part 21, 22 (Fuel cell) Cell opening end surface partition part 23 Top plate 24 Gasket 25 Gasket 26 Cross gasket 27 Cross gasket 28 Gasket 40 Heat insulating material 50 Fuel cell container 50A, 50B Left and right two chambers 51 (Fuel cell) Cell unit insertion opening 52 Rib 55 Heat insulating material 59 Column body 60 (Structure power generation chamber) Frame 60a Upper end outward flange 61, 62 Rod insertion portion 71 Anode-side electric extraction portion 72 Cathode-side electric extraction portion 80 Top plate reinforcing member 80a Lower end outward flange portion 90 (combustion chamber) frame 100 Cell block 110 Hole 120 Exhaust fuel discharge holes a to d Partition

Claims (3)

  A fuel cell comprising: a power generation chamber in which a plurality of fuel battery cells are arranged; an upper chamber in an upper part of the power generation chamber; and a partition unit that partitions the power generation chamber and the upper chamber, wherein the partition unit includes a plurality of partition units. A fuel cell comprising the fuel cell.   The fuel cell according to claim 1, wherein the plurality of partition portions are arranged at the same height. A first placement portion for placing the partition portion is provided on the inner edge of the fuel cell container that forms the power generation chamber, and the partition portion is placed on the inner side separately from the first placement portion. The fuel cell according to claim 1, further comprising a second placement portion.

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