A kind of battery stack drainage structure and solid oxide battery stack

Abstract

The present invention discloses a stack drainage structure and a solid oxide stack, including a fluid flow field, wherein the fluid flow field is provided with a fluid inlet, an inlet multi-manifold mixed flow area, a sub-airway area, an outlet multi-manifold mixed flow area and a fluid outlet connected in sequence, the sub-airway area is provided with a plurality of sub-airways distributed along the width direction, and the inlet multi-manifold mixed flow area is provided with an obstruction layer, the obstruction layer is a foam metal, and the obstruction layer is extended along the width direction. The present invention guides the fluid path through the foam metal, so that the fluid flows into the plurality of sub-airways more evenly, and the uniformity of the fluid distribution between the various sub-airways and the power output of the stack are improved. Compared with the stack without the obstruction layer, the length of the multi-manifold can be reduced under the condition of achieving the same airflow uniformity, thereby improving the volume power density of the solid oxide stack, and improving the uniformity of the physical field distribution inside the stack, thereby improving the thermal mechanical performance of the stack.

Description

Technical Field

[0001] The present invention relates to the field of solid oxide batteries, in particular to a battery stack drainage structure and a solid oxide battery stack. Background Art

[0002] Solid oxide fuel cells (SOFCs) can convert chemical energy in fuels into electrical energy for power generation, and have the advantages of high fuel efficiency and wide fuel adaptability. Solid oxide electrolyzers (SOECs) are a highly efficient energy conversion device that can convert electrical energy and thermal energy into chemical energy. They have the advantages of high efficiency, less pollution, and cheap catalysts, and have the potential for large-scale energy storage. In addition to the advantages of abundant raw material sources and the consumption of CO2 to reduce the greenhouse effect, H2O-CO2 co-electrolysis can also produce fuel gases such as H2, CO, and synthesis gas. These product gases can be used as raw materials for synthesizing useful chemical substances. Therefore, the development of SOFC and SOEC technologies is of great significance for alleviating energy crises and environmental pollution problems and promoting industrial development.

[0003] Due to the low power generation and SOEC gas yield of single-chip SOFC cells, large-area solid oxide (SOC) stacks have become the goal of industry development. The uneven distribution of physical fields such as internal components, temperature, and flow field caused by large-area and multi-layer cell stacking limits the power or gas production capacity of the stack and also reduces the thermal mechanical stability of the stack. Among them, the uneven distribution of the flow field is the main reason for the uneven distribution of other physical fields inside the battery. Therefore, it is necessary to optimize the internal flow field of the stack, reduce the flow difference between each sub-gas channel, and improve the uniformity of the distribution of the airflow between the sub-gas channels to improve the uniformity of other physical fields. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a stack drainage structure to solve the uneven distribution of gas flow in the width direction in the existing large-area multi-sub-gas channel SOC stack technology, as well as the material starvation problem caused by less sub-gas channel flow distribution in the fuel downstream, thereby improving the electrochemical reaction rate, fuel utilization and output performance.

[0005] A stack drainage structure according to a first aspect of an embodiment of the present invention includes:

[0006] A fluid flow field is provided with a fluid inlet, an inlet multi-manifold mixed flow area, a sub-airway area, an outlet multi-manifold mixed flow area and a fluid outlet which are connected in sequence, wherein the sub-airway area is provided with a plurality of sub-airways distributed along the width direction, and the inlet multi-manifold mixed flow area is provided with at least one obstruction layer, which is foam metal, and which extends along the width direction and is arranged between the fluid inlet and the entrances of the plurality of sub-airways.

[0007] The stack drainage structure of the present invention has at least the following beneficial effects:

[0008] The present invention sets an obstruction layer in the mixed flow area of ​​the inlet multi-manifold, and the obstruction layer is made of foam metal. Through the high porosity characteristics of the foam metal, the fluid path is guided and distributed, so that the fluid flows into a plurality of sub-gas channels in a uniform distribution, thereby improving the uniformity of fluid distribution between the various sub-gas channels. When the same airflow uniformity as that without the obstruction layer is achieved, the length of the multi-manifold can be reduced, thereby improving the volume power density and mass power density of the solid oxide fuel cell stack. In addition, the improvement of the fluid uniformity can reduce the temperature gradient in the width and length directions, thereby improving the thermal mechanical properties of the fuel cell stack.

[0009] According to some embodiments of the present invention, a primary airflow distribution area is formed between the obstruction layer and the fluid inlet, and a tertiary airflow distribution area is formed between the obstruction layer and the inlets of the plurality of sub-air channels.

[0010] According to some embodiments of the present invention, the fluid inlet and the barrier layer are located on the same center line, and the thickness of the barrier layer in the length direction gradually decreases along the width direction as it moves away from the center line.

[0011] According to some embodiments of the present invention, the barrier layers are symmetrically arranged with the center line as a symmetry axis.

[0012] According to some embodiments of the present invention, a side of the barrier layer facing the fluid inlet is an arc-shaped convex structure.

[0013] According to some embodiments of the present invention, the permeability of the foam metal along the width direction is higher than the permeability along the length direction.

[0014] According to some embodiments of the present invention, the metal foam is provided with an anti-oxidation coating.

[0015] According to some embodiments of the present invention, the foam metal is made of any one of foam nickel, foam manganese-copper alloy, and foam nickel-chromium alloy.

[0016] According to some embodiments of the present invention, there are multiple fluid inlets, which are periodically distributed along the width direction, and there are multiple barrier layers, which are opposite to the multiple fluid inlets one by one.

[0017] A solid oxide fuel cell stack according to a second aspect of an embodiment of the present invention comprises the fuel cell stack drainage structure.

[0018] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 It is a schematic diagram of the stack drainage structure used in the first and second embodiments of the present invention;

[0021] Figure 2 It is a schematic diagram of the conventional flow field structure of the solid oxide stack used in Comparative Examples 1 and 2 of the present invention;

[0022] Figure 3 It is a cross-sectional schematic diagram of a battery stack repeating unit of the present invention;

[0023] Figure 4 It is a comparison of the normalized airflow mass flow distribution of the sub-gas channels of the SOFC stack using the traditional flow field structure and the SOFC stack drainage structure of the present invention;

[0024] Figure 5 It is a comparison of the normalized gas flow distribution of the sub-gas channels of the SOEC stack using the traditional flow field structure and the stack drainage structure of the present invention;

[0025] Figure 6 This is the internal streamline distribution diagram of the SOFC stack in the traditional flow field;

[0026] Figure 7 This is the internal streamline diagram of the SOFC stack with an added barrier layer;

[0027] Figure 8 This is the internal streamline distribution diagram of the SOEC stack in the traditional flow field;

[0028] Fig. 9 This is the internal streamline diagram of the SOEC stack with an added barrier layer;

[0029] Figure Number:

[0030] Fluid inlet 100;

[0031] Inlet multi-manifold mixed flow area 200; primary air flow distribution area 210; tertiary air flow distribution area 220;

[0032] sub-airway area 300;

[0033] outlet multi-manifold mixed flow area 400;

[0034] Fluid outlet 500;

[0035] sub-qidao 600;

[0036] barrier layer 700;

[0037] Stack repeating unit 800; fuel side connecting plate 810; fuel electrode 820; electrolyte 830; air electrode 840; air side connecting plate 850; fuel side sub-gas channel 860; air side sub-gas channel 870; outer metal frame 880; sealing layer 890. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments.

[0043] Solid oxide fuel cells (SOFCs) can convert chemical energy in fuels into electrical energy for power generation, and have the advantages of high fuel efficiency and wide fuel adaptability. Solid oxide electrolyzers (SOECs) are highly efficient energy conversion devices that can convert electrical energy and thermal energy into chemical energy. They have the advantages of high efficiency, less pollution, and cheap catalysts, and have the potential for large-scale energy storage. In addition to the advantages of abundant raw material sources and the consumption of CO2 to reduce the greenhouse effect, H2O-CO2 co-electrolysis can also produce fuel gases such as H2, CO, and synthesis gas. These product gases can be used as raw materials for the synthesis of useful chemical substances. Therefore, the development of SOFC and SOEC technologies is of great significance for alleviating energy crises and environmental pollution problems and promoting industrial development.

[0044] Due to the low power generation and SOEC gas yield of single-chip SOFC cells, large-area solid oxide (SOC) stacks have become the goal of industry development. The uneven distribution of physical fields such as internal components, temperature, and flow field caused by large-area and multi-layer battery stacks limits the power or gas production capacity of the stack and also reduces the thermal mechanical stability of the stack. Among them, the uneven distribution of the flow field is the main reason for the uneven distribution of other physical fields inside the battery. Therefore, it is necessary to optimize the internal flow field of the stack, reduce the flow difference between each sub-gas channel 600, improve the uniformity of the distribution of the airflow between the sub-gas channels 600, and thereby improve the uniformity of other physical fields.

[0045] At present, the SOC stack mainly includes structures such as a connecting plate, an anode, an electrolyte 830, a cathode, a multi-manifold mixed flow area, an intake air channel, and an outlet air channel. The groove formed by the protruding rib structure on the connecting plate and the substrate is called a sub-air channel 600. In addition, the connector substrate is also provided with an inlet and outlet of a large air channel to allow fuel or air to enter and exit the stack. The fuel gas and air enter the stack through the large air channel, and are distributed to each layer of battery cells through a multi-manifold, and then the multi-manifold mixed flow area is used to guide and distribute the airflow into each sub-air channel 600. Finally, the gas diffuses from the sub-air channel 600 through the electrode to the three-phase line for electrocatalytic reaction. The position of the fuel and air inlet determines the main flow direction of the gas from the large air channel to the sub-air channel 600, and the design of the multi-manifold can change the specific path through which it flows. The key to reducing the difference in physical field distribution in the width and length directions is to enhance the uniformity of the airflow flowing into each sub-air channel 600 through the structural design of the large air channel and the multi-manifold mixed flow area. Therefore, the present invention proposes a fuel cell stack drainage structure, which optimizes the design of the multi-manifold mixed flow area to distribute the airflow step by step, and finally makes the airflow entering each sub-gas channel 600 more uniform, thereby reducing the difference in power generation capacity of the sub-gas channels 600 and the distribution difference of the physical field in the activation area of ​​the fuel cell stack in the width and length directions, thereby improving the power generation capacity and thermomechanical stability of the fuel cell stack.

[0046] like Figure 1 As shown, the stack drainage structure of the embodiment of the present invention includes a fluid flow field, wherein the fluid flow field of the embodiment is formed on the connecting plate and the electrode.

[0047] Specifically: the fluid flow field of the embodiment of the present invention is provided with a fluid inlet 100, an inlet multi-manifold mixed flow zone 200, a sub-air channel zone 300, an outlet multi-manifold mixed flow zone 400 and a fluid outlet 500. The fluid inlet 100, the inlet multi-manifold mixed flow zone 200, the sub-air channel zone 300, the outlet multi-manifold mixed flow zone 400 and the fluid outlet 500 are sequentially connected along the length direction. Fuel or air enters from the fluid inlet 100, then flows through the inlet multi-manifold mixed flow zone 200 to be diverted to the sub-air channel zone 300 to enter the porous electrode for electrocatalytic reaction, etc., and then converges to the fluid outlet 500 through the outlet multi-manifold mixed flow zone 400 to flow out.

[0048] As for the forming of the inlet multi-manifold mixed flow zone 200, the inlet multi-manifold mixed flow zone 200 is composed of a recessed portion on the metal plate of the fuel cell stack, which starts from the same plane and has the same depth as the sub-airway zone 300, and is surrounded by the peripheral connecting plate of the adjacent PEN component. As for the forming of the fluid inlet 100 and the fluid outlet 500, a through-hole structure is opened on the peripheral metal frame 880.

[0049] The sub-airway zone 300 of the present embodiment is provided with a plurality of sub-airways 600, and the plurality of sub-airways 600 are spaced apart and distributed along the width direction, and the sub-airway 600 extends along the length direction. The sub-airway 600 of the present embodiment is a straight channel, and in some other embodiments, the sub-airway 600 may be a curved channel or other special-shaped channel, and the inlet of the sub-airway 600 is connected to the inlet multi-manifold mixed flow zone 200, and the outlet of the sub-airway 600 is connected to the outlet multi-manifold mixed flow zone 400.

[0050] For the molding of the sub-air channel 600, the protruding rib structure on the connecting plate and the groove structure formed by the base plate are combined.

[0051] like Figure 2 The figure shows the structure of the existing fluid flow field. In the embodiment of the present invention, on the existing fluid flow field, at least one obstruction layer 700 is provided in the inlet multi-manifold mixed flow area 200. The obstruction layer 700 is protruded in the inlet multi-manifold mixed flow area 200. The obstruction layer 700 of the embodiment of the present invention is made of foam metal, and the obstruction layer 700 extends in the width direction. The obstruction layer 700 is arranged between the fluid inlet 100 and the entrances of the multiple sub-air channels 600.

[0052] The present invention guides and distributes the fluid path through the high porosity of foam metal, so that the fluid flows into multiple sub-airways 600 more evenly, thereby improving the uniformity of fluid distribution between the various sub-airways 600. In addition, while achieving the same airflow distribution uniformity, the height of the inlet multi-manifold mixing zone 200 required by the design of the present invention is reduced, thereby improving the volume power density and mass power density of the fuel cell stack, and the improvement of fluid uniformity can reduce the temperature gradient in the width and length directions, thereby improving the thermal mechanical properties of the fuel cell stack.

[0053] Furthermore, a primary airflow distribution area 210 is formed between the obstruction layer 700 and the fluid inlet 100, and a tertiary airflow distribution area 220 is formed between the obstruction layer 700 and the entrances of the plurality of sub-air channels 600, so that the fluid undergoes a flow distribution once before flowing through the obstruction layer 700, a second flow distribution after flowing through the obstruction layer 700, and a third flow distribution between the obstruction layer 700 and the entrances of the sub-air channels 600.

[0054] The fluid inlet 100 and the barrier layer 700 of this embodiment are located on the same center line, and the thickness of the barrier layer 700 in the length direction gradually decreases along the width direction as it moves away from the center line. As the distance from the center position of the fluid inlet 100 in the primary airflow distribution area 210 increases, the thickness of the area where the airflow flows through the barrier layer 700 toward the sub-airway 600 gradually decreases, that is, as the amount of fluid obtained by the primary distribution decreases, the difficulty of the fluid diffusing through the foam metal decreases, thereby achieving secondary distribution of the fluid, so that the fluid is more evenly distributed in the width direction after flowing through the foam metal. Finally, the fluid after the secondary distribution is finally mixed through the tertiary airflow distribution area 220 to achieve a more even distribution of the airflow.

[0055] The two ends of the barrier layer 700 of the embodiment of the present invention are symmetrically arranged with respect to the center line, so that the fluid flowing through the two ends of the barrier layer 700 is more evenly distributed.

[0056] Among them, the side of the barrier layer 700 facing the fluid inlet 100 is an arc-shaped convex structure, and the arc-shaped convex structure has a certain guiding effect on the fluid as the thickness of the foam metal changes. It can be understood that this embodiment uses an arc-shaped foam metal to fill part of the inlet multi-manifold mixed flow area 200, so that the thickness of the foam metal is symmetrically distributed along the center line of the fluid inlet 100, and the thickness of the foam metal gradually decreases as it moves away from the center line, thereby achieving the guidance and distribution of the gas entering the fuel cell stack, reducing the fluid flow rate of the sub-gas channel 600 at the advantageous position, that is, facing the fluid inlet 100, and increasing the fluid flow rate of the sub-gas channel 600 at the edge position, that is, away from the fluid inlet 100, to achieve an improvement in the uniformity of fluid distribution between each sub-gas channel 600.

[0057] The foam metal of the embodiment of the present invention may be made of foam nickel, foam manganese-copper alloy, foam nickel-chromium alloy, etc.

[0058] The porosity of the foam metal of the embodiment of the present invention is ≥80%, and the permeability is ≥1e-9. In addition, the permeability of the foam metal along the width direction is higher than that along the length direction. The gas permeability of the foam metal in the width direction is two orders of magnitude higher than that in the length direction, so that the diffusion flow rate of the fluid in the width direction is greater than that in the length direction, weakening the fluid flow rate at the advantageous position close to the fluid inlet 100, and increasing the fluid flow rate at the position farther away from the fluid inlet 100.

[0059] The enhanced uniformity of fluid distribution leads to improved uniformity of distribution of electrochemical reaction rate, temperature field and other physical fields, which is beneficial to reduce internal stress of the battery and improve the long-term stability of SOFC.

[0060] In some embodiments, an anti-oxidation coating may be added to the material of the metal foam to prevent a decrease in electrical conductivity due to oxidation.

[0061] In some embodiments, the size of the obstruction layer 700 can be further designed to improve the uniformity of airflow distribution. The obstruction layer 700 can be designed to be a stepped shape to further accurately control the flow distribution and improve the uniformity of airflow distribution in the sub-airway 600. The thickness and placement of the obstruction layer 700 can be further optimized and vary with the specific size of the battery stack.

[0062] In some embodiments, there are multiple fluid inlets 100, and the multiple fluid inlets 100 are spaced apart along the width direction. There are multiple barrier layers 700, and the multiple barrier layers 700 are opposite to the multiple fluid inlets 100 one by one. Figure 1 As shown, two fluid inlets 100 and two barrier layers 700 are provided, and two fluid outlets 500 are provided. The fluid inlet 100 and the fluid outlet 500 can be in various shapes such as round, elongated, square, etc.

[0063] The present invention also provides a solid oxide battery stack, comprising a plurality of battery stack repeating units 800, an inlet air duct, an outlet air duct, a peripheral metal frame 880 and a sealing layer 890, such as Figure 3 As shown, the stack repetitive unit 800 includes a fuel side connecting plate 810, a fuel electrode 820, an electrolyte 830, an air electrode 840 and an air side connecting plate 850 which are stacked in sequence. Enclosed by an outer metal frame 880 and a sealing layer 890, a fuel side sub-air channel 860 is formed between the substrate of the fuel side connecting plate 810 and the fuel electrode 820, and an air side sub-air channel 870 is formed between the air electrode 840 and the substrate of the air side connecting plate 850.

[0064] The present invention distributes the airflow step by step, and finally makes the flow entering each sub-airway 600 more uniform, thereby reducing the difference in power generation capacity of the activation area corresponding to the sub-airway 600 and the distribution difference of the physical field in the activation area of ​​the fuel cell stack in the width and length directions, thereby improving the power generation capacity and thermomechanical stability of the fuel cell stack.

[0065] The present invention provides four specific embodiments for comparing the fluid distribution uniformity achieved by a solid oxide fuel cell stack using a barrier layer 700 and a solid oxide electrolyzer stack using a barrier layer 700 and a solid oxide electrolyzer stack not using a barrier layer 700:

[0066] A comparative example of a solid oxide fuel cell is set as comparative example 1:

[0067] This comparative example is a solid oxide fuel cell stack that does not use the barrier layer 700. The solid oxide fuel cell stack of this comparative example includes an anode connecting plate, an anode layer, an electrolyte 830, a cathode layer, a cathode connecting plate, a fuel sub-gas channel 600, an air sub-gas channel 600, an inlet and outlet gas large gas channel, and a multi-manifold mixed flow area, wherein the materials used for the metal connecting plate, the anode layer, the electrolyte 830, and the cathode layer are Fe-Cr alloy stainless steel, Ni-YSZ, YSZ, and LSM-YSZ, respectively.

[0068] The fuel inlet and air inlet of the comparative stack are both Figure 2 The multi-manifold mixed flow design shown has 2-in-2-out for fuel flow and 3-in-3-out for air flow. The two large fuel flow passages are located in the middle of the left and right sides of the stack, making the airflow distribution on the left and right sides symmetrical, and the airflow on one side is symmetrically distributed along the center line of the large airflow inlet.

[0069] The thicknesses of the connecting plate substrate, connecting plate ribs, anode layer, electrolyte 830, cathode layer, and multi-manifold mixed flow area in this comparative example are 1 mm, 1 mm, 0.82 mm, 10 μm, 50 μm, and 1 mm, respectively. The total width of the stack is 153 mm and the total length is 160 mm. The inlet and outlet areas of a single large air channel are both: 8 mm*8 mm. The width of the fuel flow channel and the air flow channel, i.e., the sub-air channel 600 in this embodiment is 1 mm, and the rib width is 1 mm. The molar ratio of the inlet components of the fuel air channel in the embodiment is H2:H2O=9:1.

[0070] The above stack geometry and material property parameters are input into the calculation model, and the flow field distribution is obtained through fluid dynamics calculation, such as Figure 6 , gives the distribution of airflow in each sub-airway 600, such as Figure 4 shown.

[0071] Embodiment 1 of solid oxide fuel cell:

[0072] The present embodiment is a solid oxide fuel cell stack with a barrier layer 700. The solid oxide fuel cell stack of the present embodiment includes an anode connecting plate, an anode layer, an electrolyte 830, a cathode layer, a cathode connecting plate, a fuel sub-gas channel 600, an air sub-gas channel 600, an inlet and outlet gas large gas channel, a multi-manifold mixing area, and a foam metal barrier layer 700. The materials used for the metal connecting plate, foam metal, anode layer, electrolyte 830, and cathode layer are Fe-Cr alloy stainless steel, foam nickel, Ni-YSZ, YSZ, and LSM-YSZ, respectively.

[0073] The fuel and air sides of the stack of this embodiment are as follows Figure 1 The new multi-manifold mixed flow shown is the above-mentioned inlet multi-manifold mixed flow area 200 design. In this design, foam metal material is added to the traditional mixed flow area to form an obstacle layer 700. The thickness of the foam metal is 4 mm.

[0074] The thicknesses of the connecting plate substrate, connecting plate ribs, anode layer, electrolyte 830, cathode layer, and multi-manifold mixed flow area in this embodiment are 1 mm, 1 mm, 0.82 mm, 10 μm, 50 μm, and 1 mm, respectively. The total width of the stack is 153 mm, and the total length is 160 mm. The inlet and outlet areas of a single large airway are both 8 mm*8 mm.

[0075] In this embodiment, the width of the fuel flow channel and the air flow channel, i.e., the sub-air channel 600, is 1 mm, and the rib width is 1 mm.

[0076] The above stack geometry and material property parameters are input into the calculation model, and the flow field distribution is obtained through fluid dynamics calculation, such as Figure 7 , gives the distribution of airflow in each sub-airway 600, such as Figure 4 shown.

[0077] By comparing Example 1 with Comparative Example 1, it can be seen that in the presence of the barrier layer 700, the distribution of the airflow and flow field of each sub-gas channel 600 in the solid oxide fuel cell stack can be made more uniform.

[0078] The comparative example of the solid oxide electrolytic cell is set as comparative example 2:

[0079] The solid oxide electrolytic cell stack of this comparative example does not use the barrier layer 700. The solid oxide electrolytic cell stack of this comparative example includes an anode connecting plate, an anode layer, an electrolyte 830, a cathode layer, a cathode connecting plate, a fuel sub-gas channel 600, an air sub-gas channel 600, an inlet and outlet gas channel, and a multi-manifold mixed flow area. The materials used for the metal connecting plate, the cathode layer, the electrolyte 830, and the anode layer are Fe-Cr alloy stainless steel, Ni-YSZ, YSZ, and LSM-YSZ, respectively.

[0080] The fuel inlet and air inlet of the comparative stack are both Figure 2 The multi-manifold mixed flow design shown has 2-in-2-out for fuel flow and 3-in-3-out for air flow. The two large fuel flow passages are located in the middle of the left and right sides of the stack, making the airflow distribution on the left and right sides symmetrical, and the airflow on one side is symmetrically distributed along the center line of the large airflow inlet.

[0081] The thicknesses of the connecting plate substrate, connecting plate ribs, cathode layer, electrolyte 830, anode layer, and multi-manifold mixed flow area in this comparative example are 1 mm, 1 mm, 0.82 mm, 10 μm, 50 μm, and 1 mm, respectively. The total width of the stack is 153 mm, and the total length is 160 mm. The inlet and outlet areas of a single large airway are both 8 mm*8 mm.

[0082] In this embodiment, the width of the fuel flow channel and the air flow channel, i.e., the sub-air channel 600, is 1 mm, and the rib width is 1 mm.

[0083] In this embodiment, the molar ratio of the components at the inlet of the fuel gas channel is H2O:CO2=1:1.

[0084] The above stack geometry and material property parameters are input into the calculation model, and the flow field distribution is obtained through fluid dynamics calculation, such as Figure 8 , gives the distribution of airflow in each sub-airway 600, such as Figure 5 shown.

[0085] Example 2 of solid oxide electrolytic cell:

[0086] This embodiment is a solid oxide electrolytic cell stack with a barrier layer 700. The solid oxide electrolytic cell stack of this embodiment includes an anode connecting plate, an anode layer, an electrolyte 830, a cathode layer, a cathode connecting plate, a fuel sub-gas channel 600, an air sub-gas channel 600, an inlet and outlet gas channel, a multi-manifold mixed flow area, and a foam metal barrier layer 700. The materials used for the metal connecting plate, foam metal, cathode layer, electrolyte 830, and anode layer are Fe-Cr alloy stainless steel, foam nickel, Ni-YSZ, YSZ, and LSM-YSZ, respectively.

[0087] The fuel and air sides of the stack of this embodiment are as follows Figure 1 The new multi-manifold mixed flow shown is the design of the inlet multi-manifold mixed flow area 200 mentioned above. This design adds an obstacle layer 700 formed by foam metal material in the traditional mixed flow area, and the thickness of the foam metal is 1mm.

[0088] In this embodiment, the thicknesses of the connecting plate substrate, connecting plate ribs, cathode layer, electrolyte 830, anode layer, and multi-manifold mixed flow area are 1 mm, 1 mm, 0.82 mm, 10 μm, 50 μm, and 1 mm, respectively. The total width of the stack is 153 mm, and the total length is 160 mm. The inlet and outlet areas of a single large airway are both 8 mm*8 mm.

[0089] In this embodiment, the width of the fuel flow channel and the air flow channel, i.e., the sub-air channel 600, is 1 mm, and the rib width is 1 mm.

[0090] The above stack geometry and material property parameters are input into the calculation model, and the flow field distribution is obtained through fluid dynamics calculation, such as Fig. 9 , gives the distribution of airflow in each sub-airway 600, such as Figure 5 shown.

[0091] By comparing Example 2 with Comparative Example 2, it can be seen that in the presence of the barrier layer 700, the distribution of the airflow and flow field in each sub-gas channel 600 in the solid oxide electrolytic cell can be made more uniform.

[0092] The design of the present invention guides the airflow path by filling the multi-manifold area with a foam metal material with a thickness that gradually decreases in an arc shape to form an obstruction layer 700, so that the airflow uniformity of the solid oxide fuel cell stack large channel distributed to each sub-channel 600 is increased from 86.7% to 96.6%, and the airflow uniformity of the solid oxide electrolytic cell stack is increased from 52.4% to 85.8%. In addition, to achieve the same airflow distribution uniformity, the multi-manifold height required by the design of the present invention is reduced, thereby improving the volume power density of the stack, and the improvement of airflow uniformity can reduce the temperature gradient in the width and length directions, thereby improving the thermal mechanical properties of the stack.

[0093] The present invention solves the problem of uneven distribution of gas flow in the width direction in the existing large-area multi-sub-gas channel solid oxide fuel cell technology, as well as the problem of material starvation in the downstream of the fuel due to less flow distribution in the sub-gas channel 600, thereby improving the electrochemical reaction rate, fuel utilization and output performance.

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0095] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A stack drainage structure, characterized in that: include: A fluid flow field, comprising a fluid inlet, an inlet multi-manifold mixed flow area, a sub-airway area, an outlet multi-manifold mixed flow area and a fluid outlet which are connected in sequence, wherein the sub-airway area is provided with a plurality of sub-airways distributed along a width direction, and the inlet multi-manifold mixed flow area is provided with at least one obstruction layer, wherein the obstruction layer is a foam metal, and the obstruction layer extends along the width direction and is arranged between the fluid inlet and the entrances of the plurality of sub-airways; A primary airflow distribution area is formed between the obstruction layer and the fluid inlet, and a tertiary airflow distribution area is formed between the obstruction layer and the inlets of the plurality of sub-airways; The fluid inlet and the barrier layer are located on the same center line, and the thickness of the barrier layer in the length direction gradually decreases along the width direction as it moves away from the center line; The barrier layers are symmetrically arranged with the center line as the symmetry axis; The side of the barrier layer facing the fluid inlet is an arc-shaped convex structure; The permeability of the foam metal along the width direction is higher than the permeability along the length direction.

2. The stack drainage structure according to claim 1, characterized in that: The metal foam is provided with an anti-oxidation coating.

3. The stack drainage structure according to claim 1, characterized in that: The foam metal is made of any one of foam nickel, foam manganese-copper alloy, and foam nickel-chromium alloy.

4. The stack drainage structure according to any one of claims 1 to 3, characterized in that: There are a plurality of fluid inlets, which are spaced apart along the width direction. There are a plurality of barrier layers, which are opposite to the fluid inlets one by one.

5. A solid oxide stack, characterized in that: It comprises the stack drainage structure as described in any one of claims 1 to 4.

Images