JP5461364B2 - Seal structure of current collector rod for fuel cell - Google Patents

Description

  The present invention relates to a sealing structure of a current collecting rod (collecting electrode: current collecting tube) used in a fuel cell, for example, a solid oxide fuel cell (hereinafter referred to as “SOFC”).

  As a sealing structure of a current collector rod for a fuel cell, for example, the one disclosed in FIG. 3 of Patent Document 1 is known.

JP 2004-139818 A

In recent years, a sealing structure 51 of a current collector rod for a fuel cell as shown in FIG. 4 has been proposed in order to improve sealing performance.
The fuel cell current collector rod seal structure 51 shown in FIG. 4 is arranged on the radially outer side of the current collector rod 53 inserted into the partition wall 52 that forms the fuel gas header (for example, fuel discharge chamber) GH (for the first current collector rod). ) An insulating tube 54 is disposed, and the current collector rod 53 and the insulating tube 54 are fitted into a through hole 55 penetrating in the plate thickness direction of the partition wall 52 (fitted) and are welded and joined by a metal flange. 56 is inserted inward in the radial direction.

The flange 56 is joined to the partition wall 52 by welding so that the outer peripheral surface thereof is in contact with (adhered to) the entire inner peripheral surface of the through hole 55, and the joint between the flange 56 and the partition wall 52 is sealed by the welded portion B1. Yes.
On the radially outer side of the insulating pipe 54 located outside the fuel gas header GH, from the flange 56 side (first) Kovar pipe 57, (second current collector rod) insulating pipe 58, (second ) The Kovar tube 59 is arranged in a continuous manner, and a current collecting rod 60 made of a member different from the current collecting rod 53 is arranged at the tip (one end) of the insulating tube 54 in a continuous manner.

  The joint between the flange 56 and the Kovar tube 57 protrudes along the axial direction (vertical direction in FIG. 4) from the flange 56, and is covered by an overlap portion 56a that overlaps the radially outer portion of a part of the outer peripheral surface of the Kovar tube 57. (Sealed) The joint between the Kovar tube 57 and the insulating tube 58 protrudes from the Kovar tube 57 along the axial direction, and overlaps the radially outer portion of the outer peripheral surface of the insulating tube 58 (first). It is covered (blocked) by the wrap part 57a.

  The joint between the insulating tube 58 and the Kovar tube 59 protrudes from the Kovar tube 59 along the axial direction, and is overlapped by a (second) overlap portion 59a that overlaps a part of the outer peripheral surface of the insulating tube 58 in the radial direction. The seam between the Kovar tube 59 and the current collecting rod 60 is covered (blocked), and protrudes along the axial direction from the Kovar tube 59, and overlaps 59b that overlaps a part of the outer peripheral surface of the current collecting rod 60 in the radial direction. It is covered (blocked) by.

  Of the joint between the flange 56 and the Kovar pipe 57, the portion 61 exposed outside the fuel gas header GH is joined (sealed) by gold brazing, and the fuel between the Kovar pipe 57 and the insulating pipe 58 is connected with the fuel. The portion 62 exposed outside the gas header GH is joined (sealed) by gold brazing.

  Of the joint between the insulating pipe 58 and the Kovar pipe 59, a portion 63 exposed outside the fuel gas header GH is joined (sealed) by gold brazing, and among the joint between the Kovar pipe 59 and the current collecting rod 60, The portion 64 exposed outside the fuel gas header GH is joined (sealed) by gold brazing.

  On the other hand, the front end surface (one end surface) of the current collecting rod 60 and the outer peripheral surface of the current collecting rod 53 are joined by welding, and the inner peripheral surface at the front end of the current collecting rod 60 and the outer periphery of the current collecting rod 53 facing the inner peripheral surface. The space between the surfaces is sealed by a weld B2.

Thus, in the fuel cell collector rod seal structure 51, in order to improve the sealing performance, a gold solder having a low heat resistant temperature is used at the joint between the members, and the heat resistance is not so good. There was a problem.
Further, in the fuel cell collector rod seal structure 51, all the joints between the members are sealed by welding or gold brazing, and hot extension is not allowed, so that damage such as cracks and cracks occurs. It was the cause.
Furthermore, there is a problem that workability at the time of assembly or disassembly is not very good.

As fuel cells are highly integrated and densified, the heat resistance and workability of current collector rod seals, which were not originally recognized as issues, will become very important issues in the future. The inventor came to predict that it would be.
The present invention has been made based on such recognition, and provides a sealing structure for a current collector rod for a fuel cell that can improve heat resistance and workability without reducing sealing performance. Objective.

The present invention employs the following means in order to solve the above problems.
A sealing structure of a current collector rod for a fuel cell according to the present invention is a seal structure of a current collector rod for a fuel cell that seals the periphery of the current collector rod inserted into a partition wall that forms a fuel gas header of the fuel cell. An inner peripheral surface of a current collecting / extracting flange fitted and joined to a through hole penetrating in the thickness direction; an insulating tube located radially outside the current collecting rod and inside the current collecting / extracting flange; A gap formed between the outer peripheral surface and the outer peripheral surface is sealed by a barnacle-type elastic spring.

According to the seal structure of the current collector rod for a fuel cell according to the present invention, the insulating pipe located on the inner peripheral surface of the current collector extraction flange, on the radially outer side of the current collector rod, and on the radially inner side of the current collector extraction flange. A gap formed between the outer peripheral surface and the outer peripheral surface is sealed by a barnacle-type elastic spring.
This eliminates the need for expensive gold brazing that has been required in the past, and as a result, heat resistance and workability can be improved, and manufacturing costs can be reduced.

In the fuel cell current collector seal structure, between the lower surface of the flange portion provided at the front end of the current collector rod exposed outside the fuel gas header and the front end surface of the insulating tube, A second current collector rod made of another member is sandwiched between the outer peripheral surface at the tip of the insulating tube and the inner peripheral surface of the second current collector rod facing the outer peripheral surface. More preferably, the gap is sealed with a barnacle-type elastic spring.

According to such a sealing structure of the current collector rod for a fuel cell, a gap formed between the outer peripheral surface at the distal end portion of the insulating tube and the inner peripheral surface of the second current collector rod facing the outer peripheral surface, It is sealed by a barnacle type elastic spring.
This eliminates the need for expensive gold brazing that has been required in the past, and as a result, heat resistance and workability can be improved, and manufacturing costs can be reduced.

  In the fuel cell current collecting rod sealing structure, it is more preferable that a sleeve is provided between the insulating tube and the elastic spring.

According to such a sealing structure for a current collector rod for a fuel cell, a sleeve having a low surface roughness (fine) is arranged between the insulating tube and the elastic spring, and the elastic spring touch surface ( The seal surface) comes into contact (contact).
Thereby, even if the insulating tube is made of ceramics (for example, made of alumina) and the surface roughness of the outer peripheral surface of the insulating tube is high (rough), the sealing property can be improved without reducing the sealing property. .

A fuel cell according to the present invention includes any one of the above-described fuel cell current collector seal structures.
According to such a fuel cell, since the fuel cell collector rod seal structure with improved heat resistance and workability is provided, the heat resistance of the entire fuel cell can be improved, and the entire fuel cell can be assembled. It is possible to improve workability at the time of disassembling or disassembling.
In addition, the expensive gold brazing that has been conventionally required is unnecessary or greatly reduced, so that the manufacturing cost can be reduced.

  According to the present invention, there is an effect that heat resistance and workability can be improved without reducing sealing performance.

It is a figure which shows typically the structure at the time of applying the sealing structure of the collector rod for fuel cells which concerns on 1st Embodiment of this invention to a horizontal stripe cylindrical SOFC. It is sectional drawing which expands and shows the principal part of FIG. 1 in detail. It is sectional drawing of the sealing structure of the collector rod for fuel cells which concerns on 2nd Embodiment of this invention, Comprising: It is a figure similar to FIG. It is sectional drawing of the sealing structure of the conventional collector rod for fuel cells, Comprising: It is a figure similar to FIG.

[First Embodiment]
Hereinafter, the seal structure of the current collector rod for a fuel cell according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a diagram schematically showing a configuration when a sealing structure of a fuel cell current collector rod according to the present embodiment is applied to a horizontal-striped cylindrical SOFC, and FIG. 2 is an enlarged view of the main part of FIG. FIG.
As shown in FIG. 1, the fuel cell 1 includes a housing 2, a plurality of cell tubes (base tube) 3, an upper support 4, a lower support 5, and a first discharge current collector (collector). A second discharge side current collector plate (current collector plate) 7, and a supply side current collector plate (current collector plate) 8.

  The housing 2 houses therein a plurality of cell tubes 3, a first discharge side current collector plate 6, a second discharge side current collector plate 7, a supply side current collector plate 8 and the like. The fuel supply chamber 21, the power generation chamber 22, and the fuel discharge chamber 23 are provided.

  The fuel supply chamber 21 is a space surrounded by the housing 2 and the lower support 5 and is a space into which fuel gas used for power generation flows from the outside. In addition, inside the fuel supply chamber 21, a supply-side current collector plate 8 is disposed, and an opening end of the cell tube 3 on the fuel supply chamber 21 side is disposed.

  The power generation chamber 22 is a space surrounded by the casing 2, the upper support portion 4, and the lower support portion 5, and is a space from which air used for power generation flows in and out from the outside. Further, in the power generation chamber 22, an area where the power generation cell is provided in the cell tube 3 is arranged.

  The fuel discharge chamber 23 is a space surrounded by the casing 2 and the upper support 4 and is a space into which fuel gas after being used for power generation flows. In addition, a first discharge side current collector plate 6 and a second discharge side current collector plate 7 are disposed inside the fuel discharge chamber 23, and an open end of the fuel discharge chamber 23 of the cell tube 3 is disposed. Yes. Further, a top plate (upper plate: top plate) 23a that forms the ceiling surface (upper surface: top surface) of the fuel discharge chamber 23 has a lower end connected to the first discharge-side current collecting plate 6 (-) current collecting rod. (Collector electrode: current collector tube) 9 and a (+) current collector rod (collector electrode: current collector tube) 10 whose lower end is connected to the second discharge side current collector plate 7 are inserted. .

  The upper support 4 supports the cell tube 3 together with the lower support 5, and is disposed between the power generation chamber 22 and the fuel discharge chamber 23. In other words, the upper support portion 4 also partitions the power generation chamber 22 and the fuel discharge chamber 23.

  The lower support portion 5 supports the cell tube 3 together with the upper support portion 4 and is disposed between the power generation chamber 22 and the fuel supply chamber 21. In other words, the lower support portion 5 also partitions the power generation chamber 22 and the fuel supply chamber 21.

  The cell tube 3 generates power by receiving supply of fuel gas and air (oxygen), and the power generation cells are connected in series along the longitudinal direction of the cell tube 3 on the circumferential surface of the cylindrical base tube. Are arranged. The cell tube 3 is disposed inside the housing 2 such that one open end opens into the fuel discharge chamber 23 and the other open end opens into the fuel supply chamber 21.

The plurality of cell tubes 3 are formed to have substantially the same length and are arranged in parallel. Further, the open ends on the fuel discharge chamber 23 side of the plurality of cell tubes 3 are located on substantially the same plane, and the open ends on the fuel supply chamber 21 side are also located on the substantially same plane.
On the other hand, the plurality of cell tubes 3 includes a first cell group 3A electrically connected to the first discharge side current collector plate 6 and the supply side current collector plate 8, a second discharge side current collector plate 7, The second cell group 3 </ b> B is electrically connected to the supply-side current collector plate 8.

The first discharge side current collector plate 6 is a metal plate disposed in the fuel discharge chamber 23 of the housing 2 and is electrically connected and fixed to the end of the cell tube 3 of the first cell group 3A. And the cell tube 3 of the 1st cell group 3A is connected in parallel with the supply side current collecting plate 8. FIG. The first discharge-side current collector plate 6 is disposed on the substantially same plane as the second discharge-side current collector plate 7 and is disposed side by side with a predetermined interval.
Thus, since the 1st discharge side current collecting plate 6 and the 2nd discharge side current collecting plate 7 are arrange | positioned at intervals, both are electrically isolated.

  The second discharge side current collecting plate 7 is a metal plate disposed in the fuel supply chamber 21 of the housing 2 and is electrically connected and fixed to the end of the cell tube 3 of the second cell group 3B. And the cell tube 3 of the 2nd cell group 3B is connected in parallel with the supply side current collecting plate 8. FIG.

  The supply-side current collector plate 8 is a metal plate disposed in the fuel supply chamber 21 of the housing 2 and is electrically connected to the end portions of the cell tubes 3 of the first cell group 3A and the second cell group 3B. And fixed. Further, the supply-side current collector plate 8 connects the cell tube 3 of the first cell group 3A in parallel with the first discharge-side current collector plate 6, and the cell tube of the second cell group 3B together with the second discharge-side current collector plate 7. 3 are connected in parallel, and the cell tube 3 of the first cell group 3A and the cell tube 3 of the second cell group 3B are connected in series.

  Now, as shown in FIG. 2, the fuel cell collector rod seal structure 11 according to the present embodiment is arranged on the radially outer side of the (first) collector rod 10 inserted through the top plate 23a (for the collector rod). ) The insulating tube 31 is arranged, and the current collecting rod 10 and the insulating tube 31 are fitted (fitted) into the through hole 32 penetrating in the plate thickness direction of the top plate (partition wall) 23a and welded. The current collector outlet flange 33 is inserted inside in the radial direction.

The current collecting flange 33 has a shaft portion 33a whose outer peripheral surface at the base end portion is in contact with (is in close contact with) the entire inner peripheral surface of the through hole 32 that penetrates in the plate thickness direction of the top plate 23a, and the shaft portion 33a. A ceiling connected to (connected to) the base end, perpendicular to the direction in which the shaft portion 33a extends, and outward in the radial direction and extending along the circumferential direction. The flange part 33b which contact | connects (it closely_contact | adheres) the top | upper surface (upper surface: top surface) of the board 23a is provided. Further, a constant (predetermined) distance between the outer peripheral surface of the insulating tube 31 inserted radially inward of the current collecting and extracting flange 33 and the inner peripheral surface of the shaft portion 33a of the current collecting and extracting flange 33 (predetermined) ) Is formed, and the insulating tube 31 inserted radially inward of the current collecting and extracting flange 33 collects current via a barnacle-type elastic spring 34 made of plastically processed metal (Hastelloy X, SUS316, etc.). It is supported by the take-out flange 33.
In addition, the flange part 33b and the top plate 23a are joined by welding.

The elastic spring 34 has a shaft portion 34a whose inner peripheral surface is in contact with (is in close contact with) the outer peripheral surface of the insulating tube 31 with a certain (predetermined) width along the circumferential direction, and a direction orthogonal to the direction in which the shaft portion 34a extends. In addition, the flange portion 34b extending along the circumferential direction, one end (base end) of the shaft portion 34a, and the inner peripheral end of the flange portion 34b are connected (connected) with a smooth curved surface that widens toward the flange portion 34b. A connecting portion (connecting portion) 34c. In addition, the elastic spring 34 has a washer 35 that is in contact with (is in close contact with) the entire upper surface of the flange portion 34b and an inner peripheral side (radially inner side) of the flange portion 33b on the lower surface of the outer peripheral side (radially outer side). The flange portion 34b is sandwiched between the upper surface of the peripheral edge portion and the shaft portion 34a is disposed in a gap formed between the outer peripheral surface of the insulating tube 31 and the inner peripheral surface of the shaft portion 33a. ing.
The washer 35 and the flange portion 34b are joined by welding, and the flange portion 34b and the flange portion 33b are joined by welding.

On the other hand, between the lower surface of the flange portion 10 a provided at the upper end (tip) of the current collector rod 10 positioned (exposed) outside the fuel discharge chamber 23 and the upper end surface (tip surface) of the insulating tube 31, A (second) current collecting rod 36 made of a member different from the current collecting rod 10 is sandwiched.
The current collector rod 36 has a disc portion 36a whose entire inner peripheral surface is in contact with (adhering to) the outer peripheral surface of the upper end portion of the current collector rod 10 positioned below the flange portion 10a, and an outer peripheral side of the disc portion 36a ( And a peripheral wall portion 36b extending downward along the axial direction from the outer peripheral edge portion in the radial direction. Further, the inner peripheral surface of the peripheral wall portion 36b of the current collecting rod 36 sandwiched between the lower surface of the flange portion 10a and the upper end surface of the insulating tube 31, and the outer peripheral surface of the insulating tube 31 positioned on the radially inner side thereof. A constant (predetermined) gap is formed between them in the circumferential direction.
In addition, the flange part 10a and the disc part 36a are joined by welding.

An upper end portion of the insulating tube 31 located on the radially inner side of the peripheral wall portion 36 b is supported by the current collecting rod 36 via an elastic spring 34. The elastic spring 34 has a flange portion 34b between the washer 35 that is in contact with (is in close contact with) the entire lower surface of the flange portion 34b and the lower end surface of the peripheral wall portion 36b on the upper surface of the peripheral portion on the outer peripheral side (radially outer side). The shaft 34a is disposed in a gap formed between the outer peripheral surface of the insulating tube 31 and the inner peripheral surface of the peripheral wall portion 36b.
The washer 35 and the flange portion 34b are joined by welding, and the flange portion 34b and the peripheral wall portion 36b are joined by welding.

Reference numeral 37 in FIG. 2 denotes a member different from the current collecting rods 10 and 36, which is coupled (connected) with bolts and nuts so that the lower end surface thereof is in contact with (is in close contact with) the upper end surface of the current collecting rod 36. (Third) current collector rod is shown, and reference numeral 38 in FIG. 2 denotes a current collector connected to the upper end surface of the current collector rod 37 through bolts and nuts.
In the present embodiment, the fuel cell current collector seal structure 11 for the current collector rod 10 penetrating the top plate 23a has been described with reference to FIG. 2, but the fuel cell for the current collector rod 9 penetrating the top plate 23a is described. Since the current collector rod seal structure is the same as the fuel cell current collector seal structure 11 described above, illustration and description thereof are omitted here.

According to the seal structure 11 of the current collector rod for the fuel cell according to the present embodiment, the inner peripheral surface of the current collector extraction flange 33, the outer side in the radial direction of the current collector rod 10, and the inner side in the radial direction of the current collector extraction flange 33. A gap formed between the outer peripheral surface of the insulating tube 31 positioned is sealed by a barnacle-type elastic spring 34, and the inner surface of the current collecting rod 36 facing the outer peripheral surface at the distal end portion of the insulating tube 31 and the outer peripheral surface. A gap formed between the peripheral surface and the peripheral surface is sealed by the barnacle-type elastic spring 34.
This eliminates the need for expensive gold brazing that has been required in the past, and as a result, heat resistance and workability can be improved, and manufacturing costs can be reduced.

[Second Embodiment]
A fuel cell current collecting rod sealing structure according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a cross-sectional view of the sealing structure of the current collector rod for a fuel cell according to this embodiment, and is the same view as FIG.

As shown in FIG. 3, the seal structure 41 of the current collector rod for a fuel cell according to the present embodiment is the first described above in that sleeves 42 are provided between the insulating tube 31 and the elastic spring 34, respectively. Different from the embodiment. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

  The sleeve 42 has a cylindrical shape made of a metal (for example, stainless steel) having an inner peripheral surface that is in contact with (in close contact with) the outer peripheral surface of the insulating tube 31 and an outer peripheral surface that is in contact with (in close contact with) the inner peripheral surface of the shaft portion 34a. It is a member. Further, the sleeve 42 is fitted into the insulating tube 31 while it is heated and thermally expanded, or is fitted into the insulating tube 31 while the insulating tube 31 is cooled and thermally contracted. In other words, it is fixed (fixed) to the outer peripheral surface of the insulating tube 31 by an adhesive applied to the outer peripheral surface of the insulating tube 31.

According to the fuel cell collector rod seal structure 41 according to the present embodiment, the sleeve 42 having a low surface roughness (fine) is disposed between the insulating tube 31 and the elastic spring 34, and the outer peripheral surface of the sleeve 42 is arranged. The inner peripheral surface (seal surface) of the shaft portion 34a of the elastic spring comes into contact (contact).
Thereby, even if the insulating tube 31 is made of ceramics (for example, made of alumina) and the surface roughness of the outer peripheral surface of the insulating tube 31 is high (rough), the sealing property is improved without reducing the sealing property. Can do.

Further, according to the seal structure 41 of the current collector rod for the fuel cell according to the present embodiment, the gap formed between the inner peripheral surface of the current collector outlet flange 33 and the outer peripheral surface of the sleeve 42 is a barnacle-type elastic. A gap formed between the outer peripheral surface at the distal end portion of the insulating tube 31 and the outer peripheral surface of the sleeve 42 is sealed by the spring 34 and is sealed by the barnacle type elastic spring 34.
This eliminates the need for expensive gold brazing that has been required in the past, and as a result, heat resistance and workability can be improved, and manufacturing costs can be reduced.

Note that the present invention is not limited to the above-described embodiment, and can be modified and changed as necessary.
In addition, it is understood that the expressions “upper” and “lower” in the above description are merely expedient expressions for easily explaining the positional relationship between the components, and can be appropriately selected.

DESCRIPTION OF SYMBOLS 1 Fuel cell 10 Current collecting rod 10a Flange part 11 Seal structure 23 of a fuel cell current collecting rod 23 Fuel discharge chamber (fuel gas header)
23a Top plate (bulk)
31 Insulating tube 32 Through hole 33 Current collecting flange 34 Elastic spring 36 (Second) current collecting rod 41 Fuel cell current collecting rod sealing structure 42 Sleeve

Claims (4)

A fuel cell current collector seal structure for sealing the periphery of a current collector rod inserted through a partition wall forming a fuel cell gas header,
Positioned on the inner peripheral surface of the current collector outlet flange that is fitted and joined to the through-hole penetrating in the plate thickness direction of the partition wall, on the radially outer side of the current collector rod, and on the radially inner side of the current collector flange A sealing structure for a current collector rod for a fuel cell, wherein a gap formed between the outer peripheral surface of the insulating tube is sealed with a barnacle-type elastic spring. Between the gas header side surface of the flange portion provided at the tip of the current collector rod exposed to the outside of the fuel gas header and the tip surface of the insulating tube, a second current collector made of a member different from the current collector rod is provided. The electric pole is sandwiched,
A gap formed between the outer peripheral surface of the distal end portion of the insulating tube and the inner peripheral surface of the second current collector rod facing the outer peripheral surface is sealed with a barnacle-type elastic spring. The sealing structure of the current collector rod for a fuel cell according to claim 1.   The seal structure for a fuel cell current collector rod according to claim 1, wherein a sleeve is provided between the insulating tube and the elastic spring.   A fuel cell comprising the sealing structure for a current collector rod for a fuel cell according to any one of claims 1 to 3.

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