Gas dispersion means for fuel cell or electrolyzer, stack including same, and fuel cell system

Abstract

The present invention relates to a gas dispersion means for a fuel cell or an electrolyzer, a stack including same, and a fuel cell system. More particularly, the present invention relates a gas dispersion means capable of uniformly dispersing the flow of gas and heat in a cell package, thereby preventing gas from being concentrated only on a specific cell package and reducing damage due to heat concentration. The present invention also relates to a stack and a fuel cell system wherein cell packages including the gas dispersion means are stacked in a non-cascade structure and in a cascade structure, respectively, thereby improving fuel efficiency and increasing power generation performance.

Description

Gas dispersion means for a fuel cell or electrolytic device, a stack including the same, and a fuel cell system

[0001] The present invention relates to a gas dispersion means for a fuel cell or an electrolytic device, a stack including the same, and a fuel cell system. The invention relates to a gas dispersion means capable of preventing gas from concentrating only on a specific cell package and reducing damage caused by heat concentration by uniformly dispersing gas flow and heat to a cell package, and to a stack and a fuel cell system capable of improving fuel efficiency and increasing power generation performance by stacking cell packages including the same in a dual structure of non-cascade and cascade.

[0002] Solid Oxide Fuel Cells (SOFCs) are fuel cells that use solid ceramics as an electrolyte and operate at high temperatures ranging from 700°C to 1000°C. Compared to other types of fuel cells, they have the advantage of relatively high power generation efficiency and the ability to utilize high-quality arrays.

[0003] Typically, solid oxide fuel cells use a stack in which multiple cell packages are stacked, and in each cell package, an air electrode and a fuel electrode are positioned on opposite sides based on the electrolyte.

[0004] When oxygen and hydrogen are supplied to the air electrode and fuel electrode of the cell package, respectively, oxygen ions are generated at the air electrode due to the reduction reaction of oxygen, and the generated oxygen ions move to the fuel electrode via the electrolyte membrane.

[0005] At the fuel electrode, water is produced as oxygen ions moved from the air electrode react with hydrogen supplied to the fuel electrode. During this process, electrons generated at the fuel electrode move to the air electrode and flow into the external circuit; electricity is generated by utilizing this flow of electrons.

[0006] A stack consists of multiple cell packages, and in conventional stacks, each cell individually generates power through an electrochemical reaction using fuel and an oxidizer.

[0007] However, since unreacted fuel is emitted from individual cells, the overall fuel efficiency of the fuel cell system decreases, and there is a problem that fuel waste leads to a decrease in the performance of the fuel cell system.

[0008] Korean Registered Patent Publication No. 10-1826821 discloses technology regarding a large-capacity flat-plate solid oxide cell stack. In the prior patent, two or more flat-plate solid oxide stacks are stacked vertically, and each cell individually generates power through an electrochemical reaction using fuel and an oxidant. This requires the additional installation of a separate device to process unreacted fuel, and furthermore, since unreacted fuel is discharged from each cell, there is a problem of fuel waste.

[0009] The problem to be solved by the present invention is to provide a gas dispersion means capable of preventing gas from concentrating only on a specific cell package and reducing damage caused by heat concentration by uniformly dispersing gas flow and heat in a cell package, and a stack and fuel cell system capable of improving fuel efficiency and increasing power generation performance by stacking cell packages including the same in a dual structure of non-cascade and cascade.

[0010] The present invention provides, as a first embodiment, a gas distributing means for distributing fuel and air to a cell structure comprising a fuel electrode, an air electrode, and an electrolyte, as one of the means for solving the problem.

[0011] The gas dispersion means of the first embodiment comprises a first side rim and a second side rim, each having a plurality of fuel through openings formed therein, and a body having a plurality of slits formed parallel to each other from the first side rim toward the direction of the second side rim, and a contact plate to which the fuel electrode side edge of the cell structure is in close contact with at least a part of the body;

[0012] A fuel inlet opening and a fuel passage are formed therein, and a third side rim having a shape corresponding to the first side rim is formed therein, and a fourth side rim having a shape corresponding to the second side rim is formed therein, and a fuel outlet opening and a fuel passage are formed therein, and a body having a comb-shaped inlet flow pass communicating with the fuel inlet, a horizontal flow pass consisting of horizontal slits, a unit vertical flow pass consisting of vertical slits, and a comb-shaped outlet flow pass communicating with the fuel outlet are formed therein; and a fuel flow plate that is in contact with the side opposite to the side to which the cell structure is in contact with the two sides of the contact plate.

[0013] A middle plate comprising a fifth side rim having a shape corresponding to the third side rim and having a plurality of fuel passages formed therein, a sixth side rim having a shape corresponding to the fourth side rim and having a plurality of fuel passages formed therein, and a flat main body, wherein the middle plate is in contact with the side opposite to the side to which the contact plate is in contact among the two sides of the fuel flow plate to seal the contact surface of the fuel flow plate; and

[0014] It includes a main body having a plurality of fuel passages formed therein and a seventh side rim having a shape corresponding to the third side rim, a plurality of fuel passages formed therein and an eighth side rim having a shape corresponding to the fourth side rim, and a corrugated manifold for air injection formed perpendicular to the slit direction of the contact plate, and includes an air flow plate that is in contact with the opposite side of the two sides of the intermediate plate that is in contact with the fuel flow plate.

[0015] In addition, the present invention provides, as a second embodiment, a stack of a fuel cell or electrolytic device in which a plurality of cell packages are stacked, each cell package comprising a cell structure including a fuel electrode, an air electrode, and an electrolyte; and a gas dispersion means of the first embodiment that is in close contact with the cell structure.

[0016] In addition, the present invention provides a fuel cell system comprising the stack of the second embodiment as a third embodiment.

[0017] In the first to third embodiments above, the body of the contact plate may be provided with a unit slit consisting of a plurality of slits in a multi-stage manner.

[0018] In the first to third embodiments above, the height (H) of the unit slit adjacent to the first side rim and the second side rim may be formed higher than other unit slits not adjacent to the first side rim and the second side rim.

[0019] In the first to third embodiments above, unit diffusion channels of the fuel flow plate may be arranged at a position corresponding to the boundary line between the unit slits in the contact plate, and horizontal channels of the fuel flow plate may be arranged at a position corresponding to the horizontal line between the upper and lower slit ends of the unit slits.

[0020] In the first to third embodiments above, the horizontal flow path and the unit diffusion flow path in the fuel flow plate may be alternately and repeatedly arranged without communicating with each other.

[0021] In the first to third embodiments above, a first fuel passage and a third fuel passage are formed in the first side rim of the contact plate, a second fuel passage is formed in the second side rim of the contact plate at a position cross-opposite to the first fuel passage and a fourth fuel passage is formed in the position cross-opposite to the third fuel passage, and a fuel inlet and a fifth fuel passage are formed in the third side rim of the fuel flow plate at positions corresponding to the first fuel passage and the third fuel passage, respectively, and a fuel outlet and a sixth fuel passage may be formed at positions corresponding to the second fuel passage and the fourth fuel passage.

[0022] In the first to third embodiments above, the body may further include a cell structure seating hole formed with a shape equal to or larger than the outer diameter of the cell structure, and a ninth side rim and a tenth side rim having shapes corresponding to the first side rim and the second side rim provided by the contact plate, and a sealant that prevents leakage of fuel or air from the cell structure.

[0023] In the second or third embodiment above, the stack may include a plurality of cell packages (non-cascade layers) stacked in a non-cascade structure such that a fuel inlet and a fuel outlet are positioned at the same location; and at least one cell package (cascade layer) stacked on the outermost layer of the stacked non-cascade layers, wherein the fuel inlet is positioned at a location corresponding to a third or fifth fuel passage of the non-cascade layer and the fuel outlet is positioned at a location corresponding to a fourth or sixth fuel passage of the non-cascade layer to form a cascade structure with the non-cascade layers.

[0024] In the second or third embodiment above, the spent fuel discharged from the fuel outlet of the outermost layer among the non-cascade layers may be reinjected into the fuel inlet of the cascade layer via the sixth fuel passage and communication means of the outermost layer.

[0025] According to the present embodiment, by uniformly dispersing the flow of gas and heat throughout the cell, a gas dispersion means can prevent the gas from concentrating only on a specific cell package and reduce damage caused by heat concentration, and by stacking cell packages including the same in a dual structure of non-cascade and cascade, fuel efficiency can be improved while power generation performance can be increased.

[0026] FIG. 1 is a diagram showing the configuration of a cell package including a gas dispersion means for a fuel cell or an electrolytic device according to one embodiment of the present invention.

[0027] FIG. 2 is a detailed configuration diagram of a gas dispersion means according to one embodiment of the present invention.

[0028] Figure 3 illustrates the principle of uniformly dispersing fuel in the gas dispersion means of Figure 2.

[0029] FIG. 4 is a detailed configuration diagram of a contact plate among gas dispersion means according to another embodiment of the present invention.

[0030] FIG. 5 is a diagram showing the configuration of a stack according to one embodiment of the present invention.

[0031] FIG. 6 is a configuration diagram of a stack according to another embodiment of the present invention.

[0032] FIG. 7 is a diagram showing the configuration of a non-cascade layer and a cascade layer to illustrate the flow of fuel and air in a stack according to the embodiment of FIG. 6.

[0033] Several embodiments of the present invention will be described in detail below with reference to the drawings. However, this is not intended to limit the present invention to any specific embodiment, and it should be understood that all transformations, equivalents, and substitutions including the technical concept of the present invention are included within the scope of the present invention.

[0034] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0035] Where in this specification it is stated that one component “have” or “comprise” a sub-component, it means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0036] In this specification, the term “connect” may mean that two components are directly connected, but is not necessarily limited thereto, and may also mean that they are connected via one or more other components positioned between the components.

[0037] FIG. 1 is a diagram showing the configuration of a cell package including a gas dispersion means for a fuel cell or an electrolytic device according to one embodiment of the present invention.

[0038] A gas dispersion means according to one embodiment includes a contact plate (100), a fuel flow plate (200), an intermediate plate (300), and an air flow plate (400). A cell package (1) according to one embodiment further includes a cell structure (500) in the gas dispersion means.

[0039] As shown in FIG. 1, in one embodiment, the cell package (1) is formed by sequentially stacking a cell structure (500), a contact plate (100), a fuel flow plate (200), an intermediate plate (300), and an air flow plate (400), and when a sealant (600) is added, the sealant (600) forms the same layer as the cell structure (500).

[0040] The contact plate (100) includes a first side rim (110) and a second side rim (120) in which a plurality of fuel passages are formed, and a body (130) in which a plurality of slits parallel to each other are formed from the first side rim (110) toward the second side rim (120), and the fuel electrode side edge (502) of the cell structure (500) is in close contact with at least a part of the body (130).

[0041] The fuel flow plate (200) includes a third side rim (210) having a shape corresponding to the first side rim (110) and having a fuel inlet and a fuel passage formed therein, a fourth side rim (220) having a shape corresponding to the second side rim (120) and having a fuel outlet and a fuel passage formed therein, a comb-shaped inlet passage communicating with the fuel inlet, a horizontal passage consisting of a horizontal slit, a unit diffusion passage consisting of a vertical slit, and a comb-shaped discharge passage communicating with the fuel outlet, and is in contact with the opposite side of the two sides of the contact plate (100) to which the cell structure (500) is in contact.

[0042] The intermediate plate (300) includes a fifth side rim (310) having a shape corresponding to the third side rim (210) and having a plurality of fuel passages formed therein, a sixth side rim (320) having a shape corresponding to the fourth side rim (220) and having a plurality of fuel passages formed therein, and a main body (330) having a flat plate shape. In addition, it is in contact with the opposite side of the two sides of the fuel flow plate (200) to which the contact plate (100) is in contact, and seals the contact surface with the fuel flow plate (200).

[0043] The air flow plate (400) includes a seventh side rim (410) having a shape corresponding to the fifth side rim (310) and having a plurality of fuel passages formed therein, an eighth side rim (420) having a shape corresponding to the sixth side rim (320) and having a plurality of fuel passages formed therein, and a main body (430) having a corrugated manifold for air injection formed in a direction perpendicular to the slit direction of the contact plate (100), and is in contact with the opposite side of the two sides of the intermediate plate (300) that is in contact with the fuel flow plate (200).

[0044] The cell structure (500) is a reaction unit composed of an air electrode, an electrolyte, and a fuel electrode, and is divided into a reaction area (501) in the center and a non-reaction area (502) in the edge.

[0045] Although not shown in FIG. 1, as described above, the cell package (1)(2) of one embodiment may further include a sealant (600).

[0046] As shown in FIG. 5 or FIG. 6, which will be described later, the sealant (600) is placed between the gas dispersion means of one cell package and the air flow plate of another cell package adjacent thereto to prevent gas leakage.

[0047] That is, the sealant (600) keeps the cell structure (500) airtight so that fuel and oxygen are not mixed before passing through the cell structure (500). It may also serve as an insulation to prevent electricity generated in the cell structure (500) from leaking through unnecessary paths.

[0048] The sealant (600) includes a body having a cell structure seating hole formed with a shape equal to or slightly larger than the outer diameter of the cell structure (500), and a ninth side rim and a tenth side rim having shapes corresponding to the first side rim and the second side rim provided by the contact plate (100). Accordingly, the various gas passage holes and alignment holes formed on the first side rim and the second side rim of the contact plate (100) are formed in the same location and shape on the ninth side rim and the tenth side rim. Furthermore, it is preferable that the sealant (600) be formed with a thickness equal to or nearly equal to that of the cell structure (500).

[0049] Hereinafter, the detailed structure and gas dispersion principle of a gas dispersion means according to one embodiment will be described in detail.

[0050] FIG. 2 illustrates in detail the contact plate and the fuel flow plate among the components of the gas dispersion means according to one embodiment of the present invention.

[0051] The contact plate (100) consists of a first side rim (110), a second side rim (120), and a body (130).

[0052] A plurality of fuel passages (111, 112) are formed side by side on the first side rim (110) of the contact plate (100), and a plurality of fuel passages (121, 122) are also formed side by side on the second side rim (120). In addition, alignment holes (H) for passing an alignment shaft may be formed between the fuel passages (111, 112) and in at least one of the outer parts of each fuel passage (111, 112).

[0053] Specifically, a first fuel passage (111) and a third fuel passage (112) are formed side by side on the first side rim (110) of the contact plate (100), a second fuel passage (121) is formed on the second side rim (120) of the contact plate (100) at a position diagonally opposite the first fuel passage (111), and a fourth fuel passage (122) is formed at a position diagonally opposite the third fuel passage (112).

[0054] A plurality of slits parallel to each other are formed in the body (130) of the contact plate (100) from the first side rim (110) toward the second side rim direction (120).

[0055] As shown in the embodiment of FIG. 2, the body (130) of the contact plate (100) may be provided with a unit slit (131) consisting of a plurality of slits in multiple stages.

[0056] Here, among the multi-stage unit slits, it is preferable that the height (H) of the unit slit adjacent to the first side rim (110) and the second side rim (120) be formed higher than the height of other unit slits in the intermediate portion that are not adjacent to the first side rim (110) and the second side rim (120).

[0057] Additionally, unit diffusion channels of the fuel flow plate (200) may be arranged at a position corresponding to the boundary line (L1) between the unit slits in the contact plate (100), and horizontal channels of the fuel flow plate (200) may be arranged at a position corresponding to the horizontal line (L2) between the upper and lower slit ends of the unit slits.

[0058] At least a portion of the body (130) of the contact plate (100) is in close contact with the non-reactive region (502) of the edge portion of the cell structure (500). And the fuel flow plate (200) is in close contact with the side opposite to the side to which the cell structure (500) is in close contact among the two sides of the contact plate (100).

[0059] The fuel flow plate (200) has a third side rim (210) with a shape corresponding to the first side rim (110) of the contact plate, a fourth side rim (220) with a shape corresponding to the second side rim (120) of the contact plate, and a body (230).

[0060] A fuel inlet (211) and a fuel passage (212) are formed on the third side rim (210) of the fuel flow plate (200), and a fuel outlet (221) and a fuel passage (222) are formed on the fourth side rim (220). The fuel inlet (211) and the fuel outlet (221) are arranged to face each other diagonally.

[0061] Specifically, a fuel inlet (211) and a fifth fuel passage (212) are formed at positions corresponding to the first fuel passage (111) and the third fuel passage (112) of the first side rim (110) on the third side rim (200), respectively, and a fuel outlet (221) and a sixth fuel passage (222) of the fourth side rim (220) are formed at positions corresponding to the second fuel passage (121) and the fourth fuel passage (122) of the second side rim (120).

[0062] In the body (230) of the fuel flow plate (200), an inlet flow path (231), a unit diffusion flow path (232), and an outlet flow path (233) are formed.

[0063] The inlet passage (231) is a comb-shaped slit that communicates with the gas inlet (211).

[0064] The unit diffusion channel (232) consists of a horizontal channel (232-1) formed by a horizontal slit and vertical slits (232-2). Multiple unit diffusion channels (232) may be arranged between the inlet channel (231) and the outlet channel (233), in which case the horizontal channel (232-1) and the unit diffusion channel (232-2) are alternately arranged without communicating with each other.

[0065] The discharge channel (233) is a comb-shaped slit connected to the gas outlet (221).

[0066] Figure 3 illustrates the principle of uniform dispersion of fuel in the embodiment of Figure 2.

[0067] As shown in FIG. 3, fuel injected into the fuel inlet (211) of the fuel flow plate (200) flows into the comb-shaped inlet passage (231) connected to the fuel inlet (211), and then spreads along the x-axis (or left and right) along the long horizontal slit corresponding to the body of the comb shape, while spreading along the y-axis (or upward) through the vertical slits corresponding to the teeth of the comb shape. Here, the comb-shaped inlet passage (231) can be understood as a comb-shaped slit, but forming a comb-shaped recessed groove due to the contact of the intermediate plate (300). Thus, the fuel spreads along the x-axis and y-axis along the recessed groove, while simultaneously passing through the slit of the contact plate (100) in the z-axis direction and being input into the fuel electrode of the cell structure.

[0068] Next, referring to section A of FIG. 3, the comb-shaped inlet channel (231) and the unit diffusion channel (232) are not connected to each other, so the fuel being dispersed along the y-axis is blocked from diffusion at the ends of the comb teeth in the comb shape, but instead, upward diffusion continues in a manner that it overflows (overflows) into the horizontal channel (232-1) of the unit diffusion channel (232) through the slit of the contact plate (100) placed at the ends of the comb teeth.

[0069] Subsequently, diffusion in the x-axis (or left-right) direction occurs again in the horizontal channel (232-1) of the unit diffusion channel (232). At this time, since the horizontal channel (232-1) and the vertical slits (232-2) of the unit diffusion channel (232) are not connected to each other, when the horizontal channel (232-1) is filled with fuel, the fuel continues to diffuse upward in a manner where it overflows (overflows) into the vertical slits (232-2) through the slits of the contact plate (100).

[0070] Upward diffusion through such slits is possible because, as described above, unit diffusion channels of the fuel flow plate (200) are arranged at positions corresponding to the boundary line (L1) between the unit slits in the contact plate (100), and horizontal channels of the fuel flow plate (200) are arranged at positions corresponding to the horizontal line (L2) between the upper and lower slit ends of the unit slits.

[0071] In addition, referring to section B of FIG. 3, when fuel diffuses in the y-axis direction in a unit diffusion channel, it is systematically guided by a plurality of vertical slits (232-2) formed at regular intervals, so that fuel gas can be prevented from clumping in one area or diffusing in an irregularly deformed shape.

[0072] FIG. 4 is a configuration diagram of a contact plate of a gas dispersion means according to another embodiment of the present invention.

[0073] As seen in the embodiment of FIG. 4, in another embodiment, the body (130-1) of the contact plate (100-1) may not have multiple unit slits (131) arranged in multiple stages as in the embodiments of FIG. 2 or FIG. 3, but may have multiple long slits (131-1) connected from the top to the bottom of the body (130-1) arranged parallel to each other.

[0074] Next, the detailed configuration of a stack of cell structures including gas distribution means will be described in detail.

[0075] FIG. 5 is a diagram showing the configuration of a stack according to one embodiment of the present invention.

[0076] In the embodiment of FIG. 5, a cell package (1) is formed by sequentially stacking a cell structure (500), a contact plate (100), a fuel flow plate (200), an intermediate plate (300), and an air flow plate (400), and when a sealant (600) is added, the sealant (600) forms the same layer as the cell structure (500). Cell packages (1) with such a configuration are repeatedly stacked to form a stack.

[0077] Accordingly, in the stack according to the embodiment of FIG. 5, the fuel inlet and fuel outlet of the fuel flow plate (200) included in each cell package (10) are repeatedly arranged at the same location, and the fuel input to the fuel inlet of one end layer passes through the cell structure and is output to the fuel outlet of another end layer, having a single-pass fuel flow.

[0078] FIG. 6 is a configuration diagram of a stack according to another embodiment of the present invention.

[0079] As shown in FIG. 6, a stack of another embodiment is divided into a cell package (1) formed by sequentially stacking a cell structure (500), a contact plate (100), a fuel flow plate (200), an intermediate plate (300), and an air flow plate (400), and a cell package (2) formed by sequentially stacking a cell structure (500), a contact plate (100), a fuel flow plate (200c), an intermediate plate (300), and an air flow plate (400). Of course, a sealant (600) may be added to the cell package (1) and the cell package (2), in which case the sealant (600) forms the same layer as the cell structure (500).

[0080] In the embodiment of FIG. 6, a plurality of cell packages (1) are stacked, and at least one cell package (2) is stacked on the outermost edge of the cell package (1).

[0081] When multiple cell packages (1) are stacked, the fuel flow plate (200) of each cell package (1) is repeatedly stacked with the fuel inlet (211), the fifth fuel passage (212), the fuel outlet (221), and the sixth fuel passage (222) positioned in the same location, and in this sense, the cell package (1) in the embodiment of FIG. 6 may be named a non-cascade layer.

[0082] Meanwhile, as can be seen from the drawing symbols, the cell structure (500), contact plate (100), intermediate plate (300), and air flow plate (400) of the cell package (1) are identical to those of the cell package (2), and only the fuel flow plate (200) of the cell package (1) has some differences from the fuel flow plate (200c) of the cell package (2).

[0083] That is, the fifth fuel passage (212c), fuel inlet (211c), sixth fuel passage (222c), and fuel passage (221c) of the fuel flow plate (200c) for the cell package (2) are respectively positioned at locations corresponding to the fuel inlet (211), fifth fuel passage (212), fuel discharge (221), and sixth fuel passage (222) of the fuel flow plate (200) of the cell package (1).

[0084] Accordingly, in the embodiment of FIG. 6, the cell package (2) may be named a cascade layer in the sense that the alignment of the fuel flow plate is changed compared to the cell package (1).

[0085] Ultimately, the stack according to the embodiment of FIG. 6 can be seen as being formed by stacking a plurality of non-cascade layers and at least one cascade layer.

[0086] FIG. 7 is a diagram showing the configuration of a non-cascade layer and a cascade layer to illustrate the flow of fuel and air in a stack according to the embodiment of FIG. 6.

[0087] Each cell package (1) corresponding to a non-cascade layer is provided with a fuel inlet (10n), a fuel pass-through hole (20n), a fuel outlet (30n), and a fuel pass-through hole (40n), and each hole (10n, 20n, 30n, 40n) is sequentially matched to the positions of the first fuel pass-through port (111), the third fuel pass-through port (112), the second fuel pass-through port (121), and the fourth fuel pass-through port (122) of the contact plate constituting the cell package (1).

[0088] In addition, the cell package (2) corresponding to the cascade layer is equipped with a fuel passage hole (10c), a recycle fuel inlet (20c), a fuel passage hole (30c), and a recycle fuel outlet (40c), and each hole (10c, 20c, 30c, 40c) is sequentially matched to the positions of the fifth fuel passage port (212c), the fuel inlet port (211c), the sixth fuel passage port (222c), and the fuel outlet port (221c) of the fuel flow plate (200c) constituting the cell package (2).

[0089] In each non-cascade layer, fuel is input into the fuel inlet (10n) and flows into the fuel electrode side of the cell structure (1), and air is input into the corrugated manifold provided in the air flow plate and flows into the air electrode side of the cell structure (10). The fuel passes through the cell structure (1), is used in a chemical reaction with the air, and is then discharged through the fuel outlet (30n). In this way, the spent fuel discharged from each non-cascade layer is combined at the fuel outlet (30n) of each layer and then output to the fuel passage hole (30c) of the cascade layer.

[0090] Used fuel output through the fuel passage hole (30c) is re-entered into the recycled fuel inlet (20c) of the cascade layer through a separate communicating means (not shown in the drawing), such as a pipe. Air is input into a corrugated manifold provided in the air flow plate and flows into the air electrode side of the cell structure (10).

[0091] Fuel input into the recycled fuel inlet (20c) passes through the cell structure of the cascade layer and is reused in a chemical reaction with air, after which it is discharged into the recycled fuel outlet (40c).

[0092] Therefore, in the stack according to the embodiment of FIG. 6 or FIG. 7, the fuel is used to the maximum extent for chemical reactions in the non-cascade layer, but nevertheless, the remaining unreacted fuel can be passed back through the cascade layer to maximize the fuel utilization rate.

[0093] Although the present invention has been described above with reference to several embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

1. A gas dispersion means for dispersing and supplying fuel and air to a cell structure comprising a fuel electrode, an air electrode, and an electrolyte, A contact plate comprising a first side rim and a second side rim, each having a plurality of fuel passages formed therein, and a body having a plurality of slits formed parallel to each other from the first side rim toward the direction of the second side rim, wherein the fuel electrode side edge of the cell structure is in close contact with at least a part of the body; A fuel flow plate comprising a body having a fuel inlet and a fuel passage formed therein, a third side rim having a shape corresponding to the first side rim, a fuel outlet and a fuel passage formed therein, a fourth side rim having a shape corresponding to the second side rim, a comb-shaped inlet passage communicating with the fuel inlet, a unit diffusion passage consisting of a horizontal passage formed of a horizontal slit and a vertical slit that is not communicating with the inlet passage, and a comb-shaped discharge passage communicating with the fuel outlet that is not communicating with the unit diffusion passage, and a fuel flow plate that is in contact with the side opposite to the side to which the cell structure is in contact among the two sides of the contact plate; A fifth side rim having a shape corresponding to the third side rim having a plurality of fuel passages formed therein, a sixth side rim having a shape corresponding to the fourth side rim having a plurality of fuel passages formed therein, and a flat main body, comprising an intermediate plate that is in contact with the side opposite to the side to which the contact plate is in contact among the two sides of the fuel flow plate to seal the contact surface of the fuel flow plate; and A plurality of fuel passages are formed and a seventh side rim having a shape corresponding to the third side rim is formed, a plurality of fuel passages are formed and an eighth side rim having a shape corresponding to the fourth side rim is formed, and a corrugated manifold for air injection is formed perpendicular to the slit direction of the contact plate, comprising a main body, and an air flow plate in contact with the side opposite to the side in contact with the fuel flow plate among the two sides of the intermediate plate. A gas dispersion means for a fuel cell or electrolytic device including 2. In Paragraph 1, In the body of the above contact plate, A gas dispersion means for a fuel cell or electrolytic device having a unit slit consisting of a plurality of slits arranged in multiple stages.

3. In Paragraph 2, A gas dispersion means for a fuel cell or electrolytic device, wherein the height (H) of a unit slit adjacent to the first side rim and the second side rim is formed higher than other unit slits not adjacent to the first side rim and the second side rim.

4. In Paragraph 2, A gas dispersion means for a fuel cell or electrolytic device, wherein unit diffusion channels of the fuel flow plate are arranged at positions corresponding to the boundary line between unit slits in the contact plate, and horizontal channels of the fuel flow plate are arranged at positions corresponding to the horizontal line between the upper and lower slit ends of the unit slits.

5. In Paragraph 1, A gas dispersion means for a fuel cell or electrolytic device in which the horizontal channels and vertical slits of the unit diffusion channels in the above fuel flow plate are alternately and repeatedly arranged.

6. In Paragraph 1, A first fuel passage and a third fuel passage are formed in the first side rim of the contact plate, and a second fuel passage is formed in the second side rim of the contact plate at a position cross-opposite to the first fuel passage and a fourth fuel passage is formed at a position cross-opposite to the third fuel passage. A gas dispersion means for a fuel cell or electrolytic device, wherein a fuel inlet and a fifth fuel passage are formed at positions corresponding to the first fuel passage and the third fuel passage, respectively, on the third side rim of the fuel flow plate, and a fuel outlet and a sixth fuel passage are formed at positions corresponding to the second fuel passage and the fourth fuel passage.

7. In Paragraph 6, A gas dispersion means for a fuel cell or electrolytic device, comprising a body having a cell structure seating hole formed with a shape equal to or larger than the outer diameter of the cell structure, a ninth side rim and a tenth side rim having shapes corresponding to the first side rim and the second side rim provided by the contact plate, and further comprising a sealant that prevents leakage of fuel or air from the cell structure.

8. A cell structure comprising a fuel electrode, an air electrode, and an electrolyte; and A stack of a fuel cell or electrolytic device in which a plurality of cell packages comprising a gas dispersion means of claim 1, which is in close contact with the cell structure, are stacked.

9. In Paragraph 8, The above stack is, A plurality of cell packages (non-cascade layers) stacked in a non-cascade structure such that the fuel inlet and fuel outlet are positioned at the same location; and At least one cell package (cascade layer) that is stacked on the outermost layer of the stacked non-cascade layers, wherein a fuel inlet is positioned at a location corresponding to a third or fifth fuel passage of the non-cascade layer and a fuel outlet is positioned at a location corresponding to a fourth or sixth fuel passage of the non-cascade layer to form a cascade structure with the non-cascade layers. A stack of a fuel cell or electrolytic device including 10. In Paragraph 9, A stack of a fuel cell or electrolytic device in which spent fuel discharged from the fuel outlet of the outermost layer among the above non-cascade layers is reinjected into the fuel inlet of the cascade layer via the sixth fuel passage and communication means of the outermost layer.

11. A fuel cell system comprising a stack according to any one of claims 8 to 10.

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