JP2012186041A - Solid oxide fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid oxide fuel battery which can achieve a high power generation efficiency in regard to all of fuel battery cells while keeping down its manufacturing cost.SOLUTION: The solid oxide fuel battery comprises: a cell stack 2 formed by stacking a plurality of single cell units 8; gas supply parts 3 and 4 for supplying each fuel battery cell 6 with a fuel gas and an oxidant gas respectively; and a heat-insulating container 5 for housing the cell stack 2 and the gas supply parts 3 and 4. The gas supply parts 3 and 4 include main gas passages 11 and 13 to which the gases are supplied from outside the heat-insulating container 5, and distribution passages 12 and 14 for leading the gases to each fuel battery cell 6 from the main gas passages 11 and 13, respectively. The solid oxide fuel battery further comprises heat transmission parts 15 for transmitting heat inside the heat-insulating container 5 to the gases in the passages, which are provided in connection portions of the main gas passages 11 and 13 with the distribution passages 12 and 14, or upstream thereof.

Description

  The present invention relates to a solid oxide fuel cell including a gas supply unit that distributes fuel gas and oxidant gas to fuel cells.

As a conventional solid oxide fuel cell, there is one described in Patent Document 1, for example. The solid oxide fuel cell disclosed in Patent Document 1 includes a cell stack formed by stacking a plurality of single cell units each composed of a fuel cell and a separator.
In this solid oxide fuel cell, a gas supply unit for supplying fuel gas and oxidant gas to each fuel cell includes a cylindrical fuel gas manifold, an oxidant gas manifold, these manifolds, A plurality of pipes (for each fuel cell) for connecting the separator, a gas passage for fuel gas, a gas passage for oxidant gas, and the like formed in each separator.

The manifold is erected on a heat insulating plate that supports the cell stack so as to extend in the stacking direction (upward) of the single cell units. The said heat insulation plate comprises the bottom of the heat insulation container which accommodates a cell stack, a gas supply part, etc. FIG. In the conventional general solid oxide fuel cell, the heat insulating container is configured to maintain the temperature in the container at a predetermined power generation possible temperature.
The pipe extends from the manifold in a direction (horizontal direction) perpendicular to the stacking direction. That is, the plurality of pipes are connected to the manifold in a state where predetermined intervals are aligned in the vertical direction.

In the solid oxide fuel cell shown in Patent Document 1, fuel gas and oxidant gas are supplied from the outside of the heat insulating container to the lower end of the manifold, and are distributed from the manifold to the pipes.
In the conventional solid oxide fuel cell, the temperature inside the heat insulation container is maintained at about 800 ° C. to 1000 ° C. by heat generated by the fuel cell, heat of a heating device provided in the heat insulation container, or the like. Yes. On the other hand, the fuel gas and the oxidant gas are heated to about 500 ° C. to 600 ° C. by a preheater or the like before being supplied into the manifold. For this reason, the temperature of the fuel gas or oxidant gas supplied from the outside of the heat insulating container into the manifold rises to the temperature in the heat insulating container by flowing from the lower end portion to the upper end portion in the manifold.

JP 2006-339035 A

  In the solid oxide fuel cell shown in Patent Document 1, since the power generation efficiency differs between the lower part and the upper part of the cell stack, there is a limit to increasing the power generation efficiency. The reason why the power generation efficiency is different between the upper part and the lower part is considered to be that the temperature of the fuel gas or oxidant gas in the manifold is lowered at the lower end part of the manifold and increased at the upper end part.

  That is, since the temperature of the fuel gas or oxidant gas supplied to the fuel cell changes depending on the vertical position of the fuel cell, the power generation efficiency cannot be increased as described above. If the temperature can be raised to the same temperature as that in the heat insulating container before the fuel gas or the oxidant gas is supplied to the manifold, the above-described problems can be solved to some extent. However, in order to realize this, it is necessary to use a heating device that preheats the gas, which has a higher output, resulting in an increase in manufacturing cost.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a solid oxide fuel cell capable of obtaining high power generation efficiency in all fuel cells while keeping the manufacturing cost low. .

  In order to achieve this object, a solid oxide fuel cell according to the present invention includes a cell stack formed by stacking a plurality of single cell units each including a solid oxide fuel cell and a separator; A gas supply unit that supplies fuel gas and oxidant gas to the fuel battery cell; and a heat insulating container that contains the cell stack and the gas supply unit and that maintains a predetermined temperature. A main gas passage through which the gas is supplied from the outside of the container and a distribution passage for guiding the gas from the main gas passage to each fuel cell, respectively, and a connection portion of the main gas passage with the distribution passage Alternatively, on the upstream side thereof, a heat transfer section is provided that transfers the heat inside the heat insulating container to the gas in the passage.

  According to the present invention, in the above invention, a portion of the main gas passage to which the distribution passage is connected is formed by a gas chamber surrounded by a cylindrical wall, and the gas chamber is formed from one end in the longitudinal direction. An upstream passage that guides gas to the other end portion, and a downstream passage that is connected to the downstream end of the upstream passage and guides gas from the other end portion to the one end portion. Connected to the downstream passage, the heat transfer section is constituted by a wall portion of the gas chamber forming the upstream passage.

  According to the present invention, in the above invention, the gas chamber is formed by a cylinder provided at a position adjacent to the cell stack, and a partition that divides the inside of the cylinder into the upstream side passage and the downstream side passage. The distribution passage is formed by a gas passage formed in the separator for each fuel cell and a pipe connecting the gas passage with a downstream passage in the cylinder.

  The present invention is the above invention, wherein the gas chamber has a hole formed in the stacked separator so as to extend in the stacking direction, and a partition that divides the inside of the hole into the upstream passage and the downstream passage. The distribution passage is formed by a gas passage formed in the separator so as to extend from the hole to the fuel cell.

According to the present invention, the fuel gas and the oxidant gas supplied to the main gas passage are heated by the heat in the heat insulating container when passing through the heat transfer section. For this reason, the fuel gas and the oxidant gas that have risen to the temperature in the heat insulating container are supplied from the main gas passage to all the fuel cells through the distribution passage. In this way, when the temperature of the fuel gas and the oxidant gas is raised to the temperature in the heat insulation container, the heat in the heat insulation container is used, so the temperature of the gas is raised to the temperature in the heat insulation container by the gas heating device. Compared with the case of making it, manufacturing cost can be suppressed low.
Therefore, according to the present invention, a solid oxide fuel cell with high power generation efficiency can be provided at low cost.

1 is a block diagram showing a configuration of a solid oxide fuel cell according to the present invention. It is a front view of a cell stack and a gas supply part, and is drawing in the state which fractured | ruptured a part of cell stack in the same figure. It is sectional drawing which expands and shows a manifold. It is sectional drawing which shows other embodiment of a manifold. It is sectional drawing which shows other embodiment of a manifold. It is sectional drawing which shows the structure of a single cell unit.

(First embodiment)
An embodiment of a solid oxide fuel cell according to the present invention will be described in detail below with reference to FIG.
A solid oxide fuel cell 1 shown in FIG. 1 includes a cell stack 2, a fuel gas supply unit 3 and an oxidant gas supply unit 4 that are located in the vicinity of the side of the cell stack 2, and the cell stack 2 and gas. And a heat insulating container 5 for accommodating the supply units 3 and 4. The heat insulating container 5 is configured to keep the internal temperature at a predetermined power generation possible temperature. The power generation possible temperature of the solid oxide fuel cell 1 according to this embodiment is 600 ° C. to 900 ° C.

  The cell stack 2 is formed by stacking a plurality of unit cell units 8 each composed of a solid oxide fuel cell (hereinafter simply referred to as a fuel cell) 6 and a separator 7 in the vertical direction. As is well known in the art, the fuel cell 6 has a fuel electrode support having a flat fuel electrode, an electrolyte layer made of a flat solid oxide layered on the fuel electrode, and an air electrode. It is of shape. The fuel cell 6 is not limited to the fuel electrode support type, and may be an air electrode support type or an electrolyte support type.

  The fuel gas supply unit 3 is for supplying fuel gas to the fuel cells 6. The oxidant gas supply unit 4 is for supplying an oxidant gas to each fuel cell 6. Although not shown, the solid oxide fuel cell 1 according to this embodiment includes a fuel gas discharge part for discharging the fuel gas from the fuel cell 6. Further, the solid oxide fuel cell 1 is configured such that the oxidant gas discharged from the fuel cell 6 is diffused from the fuel cell 6 into the atmosphere.

  The fuel gas supply unit 3 includes a main gas passage 11 through which fuel gas is supplied from the outside of the heat insulating container 5, and a distribution passage 12 that leads the fuel gas from the main gas passage 11 to each fuel cell 6. It is configured. The oxidant gas supply unit 4 includes a main gas passage 13 through which the oxidant gas is supplied from outside the heat insulating container 5, and a distribution passage for guiding the oxidant gas from the main gas passage 13 to each fuel cell 6. 14.

  The distribution passages 12, 14 are provided for each fuel cell 6, and connect the downstream end portions of the main gas passages 11, 13 to each fuel cell 6. A heat transfer section 15 is provided upstream of the main gas passages 11 and 13 connected to the distribution passages 12 and 14. The heat transfer section 15 is for transferring the heat inside the heat insulating container 5 to the gas in the main gas passages 11 and 13.

  Although the heat transfer section 15 is not shown in detail in this embodiment, it is formed by the pipes constituting the main gas passages 11 and 13 and has a gas having fins for increasing the surface area. It can be formed by a passage forming member or the like. When the heat transfer section 15 is formed of a tubular body, it is disposed so as to extend in the horizontal direction at a predetermined height in the heat insulating container 5 in addition to being disposed so as to extend in the vertical direction as shown in FIG. be able to.

  According to the solid oxide fuel cell 1 shown in FIG. 1, the fuel gas and the oxidant gas supplied to the main gas passages 11 and 13 are heated in the heat insulating container 5 when passing through the heat transfer section 15. Is heated. That is, the fuel gas and the oxidant gas that have been, for example, 500 ° C. to 600 ° C. before entering the heat insulating container 5 are heated to about 800 ° C. by passing through the heat transfer section 15.

  For this reason, in the solid oxide fuel cell 1, the fuel gas and the oxidant gas that have risen to the temperature in the heat insulating container 5 are distributed from the downstream ends of the main gas passages 11, 13 to the distribution passages 12, 14. Is supplied to all the fuel cells 6. In this way, by supplying the fuel gas and the oxidant gas at the temperature in the heat insulating container 5 to all the fuel cells 6, power generation is performed with high power generation efficiency in each of the fuel cells 6.

In this embodiment, since the heat in the heat insulating container 5 is used to raise the temperature of the fuel gas and the oxidant gas to the temperature in the heat insulating container 5, the temperature of the fuel gas and the oxidant gas is used for the gas. Compared to the case where the temperature is increased to the temperature in the heat insulating container 5 by a heating device (not shown), the manufacturing cost can be kept low.
Therefore, according to this embodiment, a solid oxide fuel cell with high power generation efficiency can be provided at low cost.

(Second Embodiment)
The fuel gas supply unit and the oxidant gas supply unit can be configured as shown in FIGS. In these drawings, members that are the same as or equivalent to those described with reference to FIG. 1 are given the same reference numerals, and detailed descriptions thereof are omitted as appropriate.
A cell stack 2 of the solid oxide fuel cell 1 shown in FIG. 2 is placed on a plate 21 via a base plate 22. The plate 21 functions as a base plate for the entire system including the cell stack 2 and piping to be described later, and is installed at the bottom of the heat insulating container 5.
The solid oxide fuel cell 1 according to this embodiment includes a load mechanism 23 having a structure in which the cell stack 2 is sandwiched from above and below in cooperation with the base plate 22. The load mechanism 23 includes connecting rods 24 erected at four locations surrounding the cell stack 2, a top plate 25 attached to the upper ends of these connecting rods 24, and the upper ends of the top plate 25 and the cell stack 2. It is comprised from the compression coil spring 27 provided between the holding plates 26 of the part.

  Each separator 7 of the cell stack 2 has a fuel gas supply gas passage 31 for guiding the fuel gas to the fuel electrode of the fuel cell 6 and a fuel gas for discharging the fuel gas from the fuel electrode of the fuel cell 6. An exhaust gas passage (not shown) and an oxidant gas supply gas passage 32 for guiding the oxidant gas to the air electrode of the fuel cell 6 are formed. Ends of the gas passages 31 and 32 that open to the outer surface of the separator 7 are connected to a pipe 33, and are connected to manifolds 34 and 35 described later via the pipe 33.

The fuel gas supply gas passage 31 is connected to a fuel gas supply manifold 34 via a pipe 33. Although not shown, the fuel gas discharge gas passage is connected to the fuel gas discharge manifold via a pipe. The fuel gas discharged to the fuel gas discharge manifold is guided from the manifold to a gas circulation device outside the heat insulating container 5 through a fuel gas discharge passage (not shown).
The oxidant gas supply gas passage 32 is connected to an oxidant gas supply manifold 35 through a pipe 33. In this embodiment, the fuel gas supply gas passage 31, the oxidant gas supply gas passage 32, and the pipe 33 constitute a “distribution passage” in the present invention.

  In this embodiment, as shown in FIG. 2, the “main gas passage” in the present invention is a manifold 34, 35 to be described later, and a gas for supplying gas to the manifold 34, 35 from the outside of the heat insulating container 5. And a gas supply pipe 36. That is, the portion of the main gas passage to which the distribution passage is connected is formed by a gas chamber 38 surrounded by a cylindrical wall 37 in the manifolds 34 and 35, as shown in FIG.

  The fuel gas supply manifold 34 and the oxidant gas supply manifold 35 according to this embodiment include a base plate 39 provided on the plate 21 and a position on the base plate 39 adjacent to the cell stack 2. The cylinder 40 is positioned and a partition plate 41 that bisects the inside of the cylinder 40 in the horizontal direction. In this embodiment, the partition plate 41 constitutes a “partition wall” in the present invention. The fuel gas discharge manifold is not provided with a partition plate, and is formed only by the cylindrical body 40.

The base plate 39 is formed in a bottomed cylindrical shape that opens upward, and is connected to the gas supply pipe 36.
The cylindrical body 40 is formed by alternately stacking a plurality of cylindrical manifold members 42 and cylindrical manifold connectors 43. A hollow portion of the manifold member 42 located at the lowermost portion of the cylindrical body 40 is connected to the internal space of the base plate 39. The manifold member 42 located at the top of the cylindrical body 40 is formed in a bottomed cylindrical shape having an upper wall 42a that closes the upper end opening of the hollow portion.

The member of the manifold 42 is made of metal, and the manifold connector 43 is made of an insulating material. The other end of the pipe 33 having one end connected to the separator 7 is connected to a manifold member 42 positioned at the same height as the one end.
The partition plate 41 is an elongated plate extending in the vertical direction, and both end portions in the width direction are in close contact with the inner peripheral surfaces of the manifold member 42 and the manifold connector 43. A gap is formed between the upper end portion of the partition plate 41 and the upper wall 42a of the manifold member 42 located at the uppermost portion of the cylindrical body 40 so that gas can pass therethrough. The partition plate 41 divides the gas chambers 38 in the manifolds 34 and 35 into an upstream passage 44 located on the opposite side of the cell stack 2 and a downstream passage 45 located close to the cell stack 2.

  The gas supply pipe 36 for supplying gas into the manifolds 34 and 35 is connected to the side of the base plate 39 opposite to the cell stack 2 and is opposite to the cell stack 2 in the gas chamber 38. Gas is supplied to the upstream passage 44 located on the side. A pipe 33 for connecting the manifolds 34 and 35 and the separator 7 is connected to a side portion of the manifold member 42 adjacent to the cell stack 2, and is adjacent to the cell stack 2 of the gas chamber 38. Gas flows from the downstream passage 45 located.

  The upstream passage 44 formed in the manifolds 34, 35 supplies fuel gas or oxidant gas from one end (lower end) in the longitudinal direction (vertical direction) to the other end (upper end) of the gas chamber 38. Lead. The downstream passage 45 is connected to the downstream end (upper end) of the upstream passage 44 and guides the gas from the other end (upper end) of the gas chamber 38 to the one end (lower end).

  According to this embodiment, the fuel gas and the oxidant gas are supplied from the outside of the heat insulating container 5 to the fuel gas supply manifold 34 and the oxidant gas supply manifold 35 by the gas supply pipe 36. These manifolds 34 and 35 are heated to the same temperature as the cell stack 2 when the fuel cell is operated.

  When the fuel gas and oxidant gas supplied to the manifolds 34 and 35 flow in the upstream passage 44 in the manifolds 34 and 35 from the lower end portion to the upper end portion of the manifolds 34 and 35, It is heated by (heat in the heat insulating container 5). At this time, the fuel gas and the oxidant gas, for example, 500 ° C. to 600 ° C. before entering the heat insulating container 5 are heated to about 800 ° C. by flowing through the upstream side passage 44. That is, in this embodiment, the “heat transfer portion” referred to in the present invention is constituted by the portion of the manifolds 34 and 35 that forms the upstream passage 44.

  The gas that has risen in the upstream passage 44 to the downstream end flows into the downstream passage 45, descends in the downstream passage 45, and flows into the pipe 33 for each fuel cell 6. Therefore, also in this embodiment, the fuel gas and the oxidant gas that have been heated to the temperature in the heat insulating container 5 are supplied to all the fuel cells 6. Power generation is performed with high power generation efficiency. In addition, since the heat in the heat insulation container 5 is used to raise the temperature of the fuel gas and the oxidant gas to the temperature in the heat insulation container 5, the temperature of the fuel gas and the oxidant gas is changed to a gas heating device (not shown). ), The manufacturing cost can be kept low as compared with the case where the temperature is increased to the temperature in the heat insulating container 5.

In this embodiment, the fuel gas and the oxidant gas can be heated in the gas chamber 38 surrounded by the cylindrical walls 37 in the manifolds 34 and 35 and supplied to the distribution passage. Therefore, according to this embodiment, although the heat transfer unit 15 is provided, the gas supply units 3 and 4 can be formed compactly.
In addition, the gas chamber 38 according to this embodiment includes a cylindrical body 40 provided at a position adjacent to the cell stack 2, and the inside of the cylindrical body 40 is divided into the upstream side passage 44 and the downstream side passage 45. It is formed with the partition plate 41 to divide. The distribution passage according to this embodiment includes gas passages 31 and 32 formed in the separator 7 for each fuel cell 6, and a downstream passage 45 in the cylinder 40 is connected to the gas passages 31 and 32. And a pipe 33 to be formed.

  For this reason, according to this embodiment, the heat transfer section 15 can be configured by using a part of the manifolds 34 and 35 formed of the cylindrical body 40. Therefore, according to this embodiment, since the gas supply units 3 and 4 having the heat transfer unit 15 can be easily realized, a solid oxide fuel cell capable of further reducing the manufacturing cost is provided. Can do.

In forming the heat transfer section in the manifold, the configuration shown in FIG. 4 can be adopted. 4, members identical or equivalent to those described with reference to FIGS. 1 to 3 are given the same reference numerals, and detailed description thereof is omitted as appropriate.
The partition walls of the manifolds 34 and 35 shown in FIG. The pipe 51 is positioned at the central portion of the manifolds 34 and 35 including the cylinder body 40.

  A gap is formed between the upper end of the pipe 51 and the upper wall 42a of the manifold member 42 located at the uppermost portion of the cylindrical body 40 so that fuel gas or oxidant gas can pass therethrough. The pipe 51 penetrates the plate 21 in the vertical direction and protrudes below the plate 21. The lower end of the pipe 51 is connected to a gas supply device (not shown) for supplying fuel gas and oxidant gas.

  A gas supply pipe is not connected to the base plates 39 of the manifolds 34 and 35 according to this embodiment. The pipes 51 provided in the manifolds 34 and 35 receive heat from the cylinders 40 of the manifolds 34 and 35 during power generation, and are heated to a temperature equivalent to that of the cylinders 40 (temperature in the heat insulating container 5). Be made. By passing the fuel gas or oxidant gas through the pipe 51, the temperature of the fuel gas or oxidant gas can be raised. That is, in this embodiment, the pipe 51 in the manifolds 34 and 35 constitutes a “heat transfer section” in the present invention.

  Therefore, also in this embodiment, the fuel gas and the oxidant gas that have been heated to the temperature in the heat insulating container 5 are supplied to all the fuel cells 6. Power generation is performed with high power generation efficiency. In addition, since the heat in the heat insulation container 5 is used to raise the temperature of the fuel gas and the oxidant gas to the temperature in the heat insulation container 5, the temperature of the fuel gas and the oxidant gas is changed to a gas heating device (not shown). ), The manufacturing cost can be kept low as compared with the case where the temperature is increased to the temperature in the heat insulating container 5.

(Third embodiment)
The present invention can also be applied to a so-called internal manifold type solid oxide fuel cell. This embodiment will be described in detail with reference to FIGS. 5 and 6, the same or equivalent members as those described with reference to FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The single cell unit 8 shown in FIG. 5 is used for a so-called internal manifold type solid oxide fuel cell, and holds the fuel cell 6 by the first to fourth separator bodies 7A to 7D and the cell holder 52. Of structure. The fuel cell 6 is of a fuel electrode support type in which an electrolyte layer 6b and an air electrode 6c are stacked on a fuel electrode 6a. In this embodiment, the first to fourth separator bodies 7A to 7D and the cell holder 52 constitute a “separator” in the present invention.

  The first to fourth separator bodies 7A to 7D are each formed in a quadrangular shape in plan view by a metal plate. Circular holes 53 constituting the manifolds 34 and 35 are formed in corner portions which are the four corners of the first to fourth separator bodies 7A to 7D. The cell holder 52 includes a cell holder main body 52a formed in an annular shape with which the fuel cell 6 is fitted, and four rings 52b for forming a manifold provided on the outer peripheral portion of the cell holder main body 52a. Has been.

  In the single cell unit 8 according to this embodiment, a cell holder 52 and a fuel cell 6 are stacked on an assembly in which the first separator body 7A and the second separator body 7B are stacked. The third separator body 7C and the fourth separator body 7D are assembled on the member by overlapping them. In order to form a cell stack using this single cell unit 8, a plurality of single cell units 8 are stacked on a plate 21 (not shown).

  In the single cell unit 8 according to this embodiment, in the assembled state, the holes 53 formed in the first to fourth separator bodies 7A to 7D and the four rings 52b of the cell holder 52 are provided. The manifold is formed in four places. These manifolds are a fuel gas supply manifold 34, an oxidant gas supply manifold 35, and two fuel gas discharge manifolds 54.

  Inside the fuel gas supply manifold 34, a metal partition plate 41 constituting a partition wall referred to in the present invention is inserted. The gas chamber 38 in the fuel gas supply manifold 34 is divided into an upstream passage 44 located on the opposite side of the fuel cell 6 and a downstream passage 45 located close to the fuel cell 6 by the partition plate 41. It is divided into and. On the other hand, a pipe 51 constituting a partition wall in the present invention is inserted into the oxidant gas supply manifold 35. The gas chamber 38 in the oxidant gas supply manifold 35 is divided into an upstream passage 44 inside the pipe 51 and a downstream passage 45 outside the pipe 51.

  The upstream passage 44 and the downstream passage 45 are formed so as to penetrate all the single cell units 8 constituting the cell stack 2. A lower end portion (upstream end portion) of the upstream passage 44 is connected to a gas passage (not shown) for supplying fuel gas and oxidant gas from the outside of the heat insulating container 5 into the manifolds 34 and 35. .

  As shown in FIG. 6, the downstream passage 45 in the fuel gas supply manifold 34 includes a groove 61 formed in the upper surface of the first separator body 7A, and a hole 62 formed in the second separator body 7B. The fuel gas supply gas passage 31 is connected to the fuel electrode 6 a of the fuel cell 6. The groove 61 constitutes a part of the gas passage 31 by overlapping the second separator body 7B on the first separator body 7A and closing the upper opening of the groove 61.

  The downstream passage 45 of the oxidant gas supply manifold 35 has a groove 63 (see FIG. 6) formed in the lower surface of the fourth separator body 7D and a hole 64 (see FIG. 6) formed in the third separator body 7C. 6), and is connected to the air electrode 6c of the fuel cell 6 by an oxidant gas supply gas passage 32. The groove 63 forms a part of the gas passage 32 by overlapping the fourth separator body 7D on the third separator body 7C and closing the lower opening of the groove 63. In this embodiment, the “distribution passage” referred to in the present invention is constituted by the gas passages 31 and 32 including the grooves 61 and 63 and the holes 62 and 64.

  The fuel gas discharge manifold 54 is fueled by a gas passage formed by a groove 65 (see FIG. 5) formed in the first separator body 7A and a hole (not shown) formed in the second separator body 7B. It is connected to the fuel electrode 6 a of the battery cell 6. The groove 65 forms a part of a gas passage by overlapping the second separator body 7B on the first separator body 7A and closing the upper opening of the groove 65. The gas chamber in the fuel gas discharge manifold 54 is connected to a gas discharge passage (not shown) penetrating the plate 21 at the lower end.

  In the internal manifold type solid oxide fuel cell having the single cell unit 8 configured as described above, the gas chambers 38 inside the fuel gas supply manifold 34 and the oxidant gas supply manifold 35 are stacked separators. 7 (first to fourth separator bodies 7A to 7D and cell holder 52) and holes (holes 53 and 52b) drilled so as to extend in the stacking direction, and the inside of the hole is connected to the upstream passage 44. It is formed by a partition wall (partition plate 41, pipe 51) divided into the downstream passage 45.

  The distribution passage according to this embodiment is formed by gas passages 31 and 32 formed in the separator 7 so as to extend from the hole (the upstream passage 44 inside the hole 53 and the ring 52b) to the fuel cell 6. Is formed. The temperatures of the first to fourth separator bodies 7A to 7D and the cell holder 52 are equal to the temperature of the fuel cell 6 during power generation. In this embodiment, the fuel gas and the oxidant gas are heated to the same temperature as the fuel cell 6 when flowing through the upstream passage 44 during power generation. That is, according to this embodiment, a part of so-called internal manifolds 34 and 35 formed in the separator 7 can be used to constitute a “heat transfer section”.

Therefore, even in the case of adopting this embodiment, the fuel gas and the oxidant gas heated to the temperature in the heat insulating container 5 are supplied to all the fuel cells 6, and all the fuel cells Each battery cell 6 generates power with high power generation efficiency. In addition, since the heat in the heat insulation container 5 is used to raise the temperature of the fuel gas and the oxidant gas to the temperature in the heat insulation container 5, the temperature of the fuel gas and the oxidant gas is changed to a gas heating device (not shown). ), The manufacturing cost can be kept low as compared with the case where the temperature is increased to the temperature in the heat insulating container 5.
In particular, according to this embodiment, since the heat transfer section can be easily realized by the internal manifolds 34 and 35, the manufacturing cost can be further reduced.

  In the third embodiment, a partition plate 41 is provided in the fuel gas supply manifold 34, and a pipe 51 is provided in the oxidant gas supply manifold 35. However, each of the manifolds 34 and 35 can be partitioned into two chambers by providing the partition plate 41 in both the manifolds 34 and 35 and providing the pipe 51 in both the manifolds 34 and 35. .

  In the second embodiment and the third embodiment described above, the partition plate 41 and the pipe 51 are illustrated as partitions for dividing the manifolds 34 and 35 into the upstream passage 44 and the downstream passage 45. . However, the partition wall is not limited to the partition plate 41 and the pipe 51, and any partition wall can be used as long as it can divide the gas chamber 3 into the upstream side passage 44 and the downstream side passage 45. can do.

  DESCRIPTION OF SYMBOLS 1 ... Solid oxide fuel cell, 2 ... Cell stack, 3, 4 ... Gas supply part, 5 ... Thermal insulation container, 6 ... Fuel cell, 7 ... Separator, 7A-7D ... 1st-4th separator main body, 8 ... single cell unit 11, 13 ... main gas passage, 12, 14 ... distribution passage, 15 ... heat transfer section, 21 ... plate, 31, 32 ... gas passage, 34 ... fuel gas supply manifold, 35 ... oxidation Agent gas supply manifold, 38 ... gas chamber, 40 ... cylindrical body, 41 ... partition plate, 44 ... upstream side passage, 45 ... downstream side passage, 51 ... pipe, 52 ... cell holder, 52b ... ring, 53 ... hole.

Claims (4)

A cell stack formed by laminating a plurality of single cell units each comprising a solid oxide fuel cell and a separator;
A gas supply unit for supplying a fuel gas and an oxidant gas to each of the fuel cells;
A heat insulating container that contains the cell stack and the gas supply unit and maintains a predetermined temperature;
The gas supply unit includes a main gas passage through which the gas is supplied from outside the heat insulating container,
It is composed of a distribution passage for guiding gas from the main gas passage to each fuel cell,
A heat transfer section for transmitting heat inside the heat insulating container to the gas in the main gas passage is provided at a connection portion of the main gas passage with the distribution passage or upstream thereof. Solid oxide fuel cell. The solid oxide fuel cell according to claim 1, wherein a portion of the main gas passage to which the distribution passage is connected is formed by a gas chamber surrounded by a cylindrical wall,
The gas chamber has an upstream passage that guides gas from one longitudinal end to the other end, and a downstream passage that is connected to the downstream end of the upstream passage and guides gas from the other end to the one end. And consists of
The distribution passage is connected to the downstream passage;
The solid oxide fuel cell according to claim 1, wherein the heat transfer section is constituted by a wall portion of a gas chamber that forms the upstream passage. 3. The solid oxide fuel cell according to claim 2, wherein the gas chamber is divided into a cylinder provided at a position adjacent to the cell stack, and the inside of the cylinder is divided into the upstream side passage and the downstream side passage. Formed by partition walls,
The distribution passage is formed by a gas passage formed in the separator for each fuel cell and a pipe connecting a downstream passage in the cylinder to the gas passage. Fuel cell. 3. The solid oxide fuel cell according to claim 2, wherein the gas chamber has a hole formed in the stacked separator so as to extend in a stacking direction, and the upstream side passage and the downstream side passage through the hole. Formed by partition walls, and
The distribution passage is formed by a gas passage formed in the separator so as to extend from the hole to the fuel cell.

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