JP4481580B2 - Solid oxide fuel cell assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state electrolyte fuel cell assembly, and more particularly relates to a solid electrolyte fuel cell assembly in the form of gas supply means is disposed between the juxtaposed cell stack.
[0002]
[Prior art]
As a next-generation energy, in recent years, a polymer electrolyte, phosphoric acid, various forms of fuel cell power generation system, such as molten carbonate and solid oxide has been proposed. In particular, the solid electrolyte fuel cell power generation system is operating temperatures as high about 1000 ° C., the power generation efficiency is high, has the advantages such as it is waste heat utilization, research and development has been promoted.
[0003]
In a typical example of the solid electrolyte fuel cell power generation system, as disclosed in Patent Document 1, the cell stack is formed by placing a substantially vertically extending cells in the horizontal direction, such a cell stack in the horizontal direction The fuel cell assembly is configured in parallel. Usually, each cell is provided with a fuel gas flow path extending through in the vertical direction, and a fuel gas, which may be hydrogen, is caused to flow through the fuel gas flow path. Between the cell stacks, oxygen-containing gas supply means is disposed, and oxygen-containing gas, which may be air, is supplied through the oxygen-containing gas supply means. The oxygen-containing gas supply means is composed of a number of tubular members arranged in parallel between the cell stacks.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-149976
[Problems to be solved by the invention]
And Thus, in the conventional solid electrolyte fuel cell assembly described above, in connection with the oxygen-containing gas supply means consisting of a plurality of tubular members, there are problems to be solved as follows. That is, the oxygen-containing gas is caused to flow through the tubular members disposed in the extending direction of each of the cells and discharged from the tip thereof, and thus discharged in the extending direction of each of the cells. The supply of oxygen-containing gas to each cannot be performed with high efficiency. In addition, since the tubular member needs to have sufficient heat resistance, it is necessary to form the tubular member from a high heat resistant material such as ceramic, and disposing a large number of such tubular members considerably increases the manufacturing cost. .
[0006]
The present invention has been made in view of the above-mentioned facts, and its main technical problem is that the gas supply means can be improved to supply the oxygen-containing gas to each of the cells with sufficient efficiency. can be manufactured inexpensively as compared to the solid oxide fuel cell assembly, it is to provide a new and improved solid electrolyte fuel cell assembly.
[0007]
[Means for Solving the Problems]
According to the present invention, the gas supply means comprises a hollow plate-like member extending in the vertical direction and in the cell arrangement direction, and a gas inlet is formed at the upper end of the hollow plate-like member, The lower end portion of both side walls of the plate-like member facing the cell stack has slits extending along the cell arrangement direction or a plurality of holes formed at intervals along the cell arrangement direction. The main technical problem is achieved by forming the configured gas outlet .
[0008]
That is, according to the present invention, the a solid electrolyte fuel cell assembly to achieve the principal object, the cell stack constructed by arranging in a row a plurality of cells extending in the vertical direction, the cell stack structure A solid oxide fuel cell assembly in which a plurality of cells are arranged in parallel so that side surfaces along the arrangement direction of the cells face each other, and a gas supply means is arranged between the cell stacks.
The gas supply means is composed of a hollow plate-like member extending in the vertical direction and in the cell arrangement direction, and a gas inlet is formed at the upper end of the hollow plate-like member. The lower end of both side walls of the shaped member facing the cell stack is composed of slits extending along the cell arrangement direction or a plurality of holes formed at intervals along the cell arrangement direction. has been that gas discharge port is formed, the solid electrolyte fuel cell assembly is provided, characterized in that.
[0010]
In the solid electrolyte fuel cell assembly of the present invention, between a pair of the cell stack, it may be arranged a single hollow plate-like member in place of a number of tubular members, thus reducing the manufacturing cost . Oxygen-containing gas (or fuel gas) is discharged from the hollow plate-shaped gas discharge port formed in the lower end portion side walls, and thus is discharged toward the cell stack is supplied to each fuel cell with high efficiency The
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, with reference to the accompanying drawings which illustrate a preferred embodiment of the constructed solid electrolyte fuel cell assembly according to the present invention will be described in detail.
[0012]
Figure 1 illustrates the main parts of a preferred embodiment of the constructed solid electrolyte fuel cell assembly according to the present invention. The illustrated assembly includes a housing 4 having a substantially rectangular parallelepiped shape. The housing 4 includes an outer frame 6 formed of a heat-resistant metal and a heat insulating material layer 8 stretched on the inner surface of the outer frame 6. It is configured. The heat insulating material layer 8 can be formed from an appropriate ceramic. A horizontal partition plate 10 extending substantially horizontally is disposed at the lower part of the housing 4, and a fuel gas manifold chamber 12 below the partition plate 10 and a power generation / combustion chamber 14 above the partition plate 10. It is divided into and. The partition plate 10 desirably has excellent airtightness and heat insulation, and is preferably formed, for example, by pouring inorganic cement into a porous ceramic plate so that at least the upper surface portion is solid. .
[0013]
A fuel gas manifold 16 is disposed in the fuel gas manifold chamber 12. The fuel gas manifold 16 is connected to a fuel gas supply source 19 via a fuel gas introduction pipe 18 that extends through the lower portion of the side wall of the housing 4. A large number of fuel gas ejection holes (not shown) are arranged on the upper surface of the fuel gas manifold 16 at appropriate intervals in the left-right direction and the direction perpendicular to the paper surface in FIG. More on pores later).
[0014]
Above the power generation / combustion chamber 14, a horizontal wall 20 that extends substantially horizontally and upright walls 22 that extend substantially vertically upward from the four peripheral edges of the horizontal wall 20 (two of the four upright walls 22 are provided). A refractory metal compartment member 24 is provided (shown in FIG. 1). A horizontal plate 26 is fixed between the upright walls 22 of the partition member 24 and spaced upward from the horizontal wall 20. The horizontal wall 20 of the partition member 24, the four upright walls 22, and the horizontal plate 26 An oxygen-containing gas manifold 28 is formed. The oxygen-containing gas manifold 28 is connected to an oxygen-containing gas supply source 32 via a heat exchanging means 30 as schematically shown in FIG.
[0015]
In the power generation / combustion chamber 14, four cell stacks 34 a, 34 b, 34 c and 34 d are arranged in parallel at intervals in the left-right direction in FIG. 1 (more specifically, the cell stack will be described later). Are arranged in parallel so that the side surfaces in the arrangement direction of the cells facing each other face each other). 2 and FIG. 2, the cell stacks 34a, 34b, 34c, and 34d extend in the vertical direction, that is, the vertical direction in FIG. 1 and the direction perpendicular to the paper surface in FIG. A plurality of cells (5 in the illustrated case) are arranged in a row in a direction perpendicular to the paper surface in FIG. 1 and in a vertical direction in FIG. As clearly shown in FIG. 2, each of the cells 36 includes an electrode support substrate 38, a fuel electrode layer 40 that is an inner electrode layer, a solid electrolyte layer 42, an oxygen electrode layer 44 that is an outer electrode layer, and an interconnector 46. Has been.
[0016]
The electrode support substrate 38 is a plate-like piece elongated in the vertical direction, and has both flat end faces and semicircular side faces. A plurality (four in the illustrated example) of gas passages 48 are formed in the electrode support substrate 38 so as to penetrate the electrode support substrate 38 in the vertical direction. As understood from FIG. 1, the lower end portion of the electrode support substrate 38 extends through the partition plate 10 into the fuel gas manifold chamber 12, and the lower end thereof is connected to the upper surface of the fuel gas manifold 16. each of the fuel gas injection hole formed on an upper surface of the fuel gas manifold 16 (not shown) is caused to communicate with the lower end of the gas passage 4 8 formed on the electrode support substrate 38. The oxygen electrode layer 44 in the cell 36 is disposed above the partition plate 10, and thus in the power generation / combustion chamber 14, and does not extend into the fuel gas manifold chamber 12.
[0017]
The interconnector 46 is disposed on one end surface (the upper end surface in FIG. 2) of the electrode support substrate 38. The fuel electrode layer 40 is the other end surface of the electrode support substrate 38 is disposed on and both side (lower end surface in FIG. 2), both ends thereof are brought bonded to both ends of the interconnect data 46. The solid electrolyte layer 42 is disposed so as to cover the entire fuel electrode layer 40, and both ends thereof are joined to both ends of the interconnector 46. Oxygen electrode layer 44, on the main portion of the solid electrolyte layer 42, i.e., the electrode support substrate 38 and the other end surface cover on part of, is disposed, it allowed located opposite the interconnect data 46 across the electrode support substrate 38 It has been.
[0018]
A current collecting member 50 is disposed between adjacent cells 36 in each of the cell stacks 34a, 34b, 34c, and 34d, and the interconnector 46 of one cell 36 and the oxygen electrode layer 44 of the other cell 36 are connected. Connected. In each of the cell stacks 34a, 34b, 34c, and 34d, current collecting members 50 are disposed at both ends, that is, the upper end surface and the lower end surface of the cell 36 positioned at the upper end and the lower end in FIG. The current collecting member 50 disposed at the upper ends of the cell stacks 34a and 34b is connected by the conductive member 52, and the current collecting member 50 disposed at the lower ends of the cell stacks 34b and 34c is also connected by the conductive member 52. A current collecting member 50 disposed at the upper ends of the cell stacks 34 c and 34 d is also connected by a conductive member 52. Further, a conductive member 52 is connected to the current collecting member 50 disposed at the lower end of the cell tack 34a, and the conductive member 52 is also connected to the current collecting member 50 disposed at the upper end of the cell stack 34d. Thus, all cells 3 6 are electrically connected in series.
[0019]
More specifically about the cell 36, the electrode support substrate 38 is gas permeable to allow fuel gas to permeate to the anode layer 40, and is also conductive to collect current via the interconnector 46. Can be formed from a porous conductive ceramic (or cermet) that satisfies such requirements. In order to manufacture the electrode support substrate 38 by simultaneous firing with the fuel electrode layer 40 and / or the solid electrolyte layer 42, it is preferable to form the electrode support substrate 38 from an iron group metal component and a specific rare earth oxide. In order to provide the required gas permeability, it is preferable that the open porosity is in the range of 30% or more, in particular 35 to 50%, and the conductivity is also 300 S / cm or more, in particular 440 C / cm or more. Is preferred. The fuel electrode layer 40 can be formed of a porous conductive ceramic, for example, ZrO ₂ (referred to as stabilized zirconia) in which a rare earth element is dissolved and Ni and / or NiO. The solid electrolyte layer 42 has a function as an electrolyte for bridging electrons between electrodes, and at the same time has a gas barrier property to prevent leakage between the fuel gas and the oxygen-containing gas. It is necessary and is usually formed from ZrO ₂ in which ₃ to 15 mol% of a rare earth element is dissolved. The oxygen electrode layer 44 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. Oxygen electrode layer 44 is required to have a gas permeable, open porosity of 20% or more, and preferably in the range especially from 30 to 50%. The interconnector 46 can be formed from a conductive ceramic, but it must have resistance to reduction and oxidation because it contacts the fuel gas, which may be hydrogen gas, and the oxygen-containing gas, which may be air. In addition, a lanthanum chromite perovskite oxide (LaCrO ₃ oxide) is preferably used. Interconnect motor 46 must be dense to prevent leakage of the oxygen-containing gas flowing outside of the fuel gas and the electrode support substrate 38 through the gas passage 48 formed in the electrode support substrate 38, 93% As described above, it is particularly desirable to have a relative density of 95% or more. The current collecting member 50 can be composed of a member having an appropriate shape formed from a metal or alloy having elasticity, or a member obtained by adding a required surface treatment to a felt made of metal fiber or alloy fiber. The conductive member 52 can be formed from an appropriate metal or alloy.
[0020]
The description will be continued with reference to FIG. 3 together with FIG. 1 and FIG. 2, and the hollows constituting the oxygen-containing gas supply means are provided between the cell stacks 34a, 34b, 34c and 34d disposed in the power generation / combustion chamber 14. A plate-like member 54 is provided. The hollow plate-like member 54 can be formed from a heat-resistant material such as an appropriate ceramic. Hollow plate-like member 54 is the cell stack 34a, 34b, disposed between 34c and 34d, it is caused to extend substantially in the vertical person direction. As will be clearly understood by reference to FIG. 3, the upper end of the hollow plate-shaped member 54 the oxygen-containing gas inlet 56 is formed. In the illustrated embodiment, the oxygen-containing gas introduction port 56 is configured by a slit extending at the upper end of the hollow plate-like member in the vertical direction (the arrangement direction of the cells 36) in FIG. A flange 58 protruding substantially horizontally is formed at the upper end of the hollow plate-shaped member 54, and the oxygen-containing gas inlet 56 is surrounded by the flange 58. Below ends of both side walls of the hollow plate-shaped member 54 the oxygen-containing gas discharge port 60 is formed. In the illustrated embodiment, the oxygen-containing gas outlet 60 has the lower end portions of both side walls of the hollow plate-like member 54 in the arrangement direction of the cells 36 (that is, the direction perpendicular to the paper surface in FIG. 1 and the vertical direction in FIG. 2). It is comprised from the slit elongated along. As can be understood by referring to FIG. 1, the upper end of the hollow plate-like member 54 is positioned in a corresponding opening formed in the horizontal wall 20 of the partition member 24, and thus the oxygen-containing gas inlet 56. Is opened in an oxygen-containing gas manifold 28. The lower end of the hollow plate-like member 54 is positioned somewhat above the partition plate 10, and therefore at the lower end of the power generation / combustion chamber 14.
[0021]
Modification of the hollow plate-like member is shown in FIG. In the hollow plate-shaped member 154 shown in FIG. 4, the oxygen-containing gas discharge port 160 is arranged at the lower ends of both side walls of the hollow plate-shaped member 154 in the arrangement direction of the cells 36 (that is, the direction perpendicular to the paper surface in FIG. and a vertical direction) a plurality of holes formed at intervals along the in FIG. The other structure of the hollow plate member 154 is substantially the same as that of the hollow plate member 54 shown in FIG.
[0022]
In the solid electrolyte fuel cell assembly of as described above, through the fuel gas inlet pipe 18 from the fuel gas supply source 19, for example, a city gas itself hydrogen obtained by reforming in a known suitable manner Good fuel gas is supplied to the fuel gas manifold 16. Then, such fuel gas is introduced into the lower end of the gas passage 48 which is formed from the fuel gas manifold 16 to each of the electrode support substrate 38 of the cell 36, is caused to flow upwardly through the gas passage 4 8. On the other hand, the oxygen-containing gas supply source 32 supplies an oxygen-containing gas, which may be air, to the oxygen-containing gas manifold 28 through the heat exchange means 30. The oxygen-containing gas supplied to the oxygen-containing gas manifold 28 flows into the hollow plate-shaped member 54 from the oxygen-containing gas introduction port 56, flows down through the hollow plate-shaped member 54, and is discharged from the oxygen-containing gas discharge port 60. The The oxygen-containing gas outlet 60 is formed on both side walls of the hollow plate-like member 54 and is directed to the cell stacks 34a, 34b, 34c and 34d. Accordingly, the oxygen-containing gas is ejected toward the cell stacks 34a, 34b, 34c and 34d at the lower end of the power generation / combustion chamber 14, and then the inside of the power generation / combustion chamber 14 is raised. Thus, each cell 36 of the cell stacks 34a, 34b, 34c and 34d is supplied sufficiently effectively. In each cell 36, an electrode reaction of the following formula (1) is generated in the oxygen electrode layer 44, and an electrode reaction of the following formula (2) is generated in the fuel electrode layer 40 to generate electric power.
[0023]
Oxygen electrode: 1 / 2O ₂ + 2e ⁻ → O ²⁻ (solid electrolyte) (1)
Fuel electrode: ^{O 2-(solid} _{electrolyte) + H 2 → H 2 O} + 2e - ··· (2)
[0024]
The fuel gas flowing through the gas passage 48 of the electrode support substrate 38 in the cell 36 that has not been used for the electrode reaction is caused to flow into the power generation / combustion chamber 14 from the upper end of the electrode support substrate 38. The fuel gas discharged into the power generation / combustion chamber 14 is combusted simultaneously with the outflow. Appropriate ignition means (not shown) is provided in the power generation / combustion chamber 14, and when the fuel gas starts to flow out to the power generation / combustion chamber 14, the ignition means is activated and combustion is started. . The oxygen contained in the oxygen-containing gas supplied to the power generation / combustion chamber 14 through the hollow plate-like member 54 is used for combustion. The combustion gas is supplied to the heat exchanging means 30 through an appropriate flow path means (not shown), and is discharged from the housing 4 after exchanging heat with the oxygen-containing gas in the heat exchanging means 30.
[0025]
Have been described in detail preferred embodiments of the constructed solid electrolyte fuel cell assembly with reference to the accompanying drawings in accordance with the present invention, the present invention is not limited to the implementation form that written, the present invention It should be understood that various changes and modifications can be made without departing from the scope. For example, in the illustrated embodiment, the fuel gas is allowed to flow through the gas passage formed in the electrode support substrate. However, the oxygen-containing gas is caused to flow through a gas passage formed in the electrode support substrate (in this case, the oxygen-containing gas is supplied to a gas manifold disposed below the partition plate 10 to form a hollow plate-like member. to 54 or 154 for supplying fuel gas to) the form of a solid electrolyte fuel cell assembly can be applied to the present invention.
[0026]
【The invention's effect】
According to the solid electrolyte fuel cell assembly of the present invention, it is possible to supply the oxygen-containing gas with sufficient efficiency to each of the cells, and also can be manufactured inexpensively as compared with the conventional solid electrolyte fuel cell assembly .
[Brief description of the drawings]
Longitudinal sectional view showing a main part of a preferred embodiment of the constructed solid electrolyte fuel cell assembly according to the invention; FIG.
Figure 2 is a cross-sectional view showing a main portion of the solid electrolyte fuel cell assembly shown in FIG.
[Figure 3] Slope view showing a hollow plate-shaped member in the solid electrolyte fuel cell assembly shown in FIG.
FIG. 4 is a perspective view showing a modification of the hollow plate member.
[Explanation of symbols]
4: Housing 12: Fuel gas manifold chamber 14: Power generation / combustion chamber 16: Fuel gas manifold 28: Oxygen-containing gas manifold 30: Heat exchange means 34a: Cell stack 34b: Cell stack 34c: Cell stack 34d: Cell stack 36: Cell 38: electrode support substrate 40: fuel electrode layer 42: solid electrolytic chamber layer 44: oxygen electrode layer 46: interconnector 48: gas passage 50: current collecting member 52: conductive member 54: hollow plate member (oxygen-containing gas supply means) )
56: Oxygen-containing gas inlet 60: Oxygen-containing gas outlet

Claims (1)

The cell stack constructed by arranging in a row a plurality of cells extending in the vertical direction, together with the side along the arrangement direction of the cells constituting the cell stack arranged in parallel a plurality so as to face, the cell stack In a solid oxide fuel cell assembly having a gas supply means disposed therebetween,
The gas supply means is composed of a hollow plate-like member extending in the vertical direction and in the cell arrangement direction, and a gas inlet is formed at the upper end of the hollow plate-like member. The lower end of both side walls of the shaped member facing the cell stack is composed of slits extending along the cell arrangement direction or a plurality of holes formed at intervals along the cell arrangement direction. A solid oxide fuel cell assembly characterized in that a gas discharge port is formed.

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