Self-pressurization device for solid oxide stack

Abstract

The invention relates to a self-pressurization device for a solid oxide galvanic pile, which comprises a base, a galvanic pile, a pressing plate, a ball, a pressing block and a positioning column, one end of the positioning column is connected with the base, the other end of the positioning column is connected with the pressing block, the galvanic pile and the pressing plate are arranged between the base and the pressing block, and the pressing plate is arranged between the base and the pressing block. The pressing plate is arranged above the electric pile, and the ball is arranged between the pressing block and the pressing plate. The core of the device is that a specially designed base and a specially designed pressing plate are matched with a pressing block, a sleeve and other components to provide constant fastening pressure for a galvanic pile in a full life cycle. The device is compact in structure and convenient to mount and dismount, can be directly used in complex environments such as storage, transportation and high-temperature operation without any operation after being mounted, and has high practical value.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide battery stacks, and in particular to a self-pressurizing device for solid oxide battery stacks. Background Art

[0002] Solid oxide stacks include solid oxide fuel cell stacks and solid oxide electrolyzer stacks, which are all-solid-state electrochemical devices that efficiently convert electrical energy and chemical energy. They are usually composed of plate-type single cells, metal connecting plates, sheet seals, sheet current collectors and other components in the longitudinal direction, in the same vertical center spatial orientation, with a preset interaction force, forming a composite structure, generally working under high temperature conditions of 600-800℃, and are designed with independent channels for the flow of reducing gas and oxidizing gas.

[0003] 1) As a composite structure with a large number of components stacked together, the outer components are prone to tilt or deflect due to horizontal forces, and the inner components are prone to displacement due to vibration, resulting in failure of sealing between the stack interfaces or poor electrical contact. The consequence of this deviation of the stack from the ideal structure is the performance degradation of the stack under high-temperature working conditions. Similarly, the above-mentioned horizontal forces, vibrations and other unfavorable factors also need to be avoided under high-temperature working conditions. 2) On the other hand, applying vertical forces to the stack is conducive to the close combination of the components, thereby improving the airtightness and overcoming the horizontal forces, as well as reducing the contact resistance between the components, and ultimately improving the performance of the stack. Furthermore, controlling the vertical force to always be at a preset size can prevent the stack from being damaged by the impact of changing mechanical forces, and can ensure that the stack works stably under the preset ideal pressure. 3) When the stack is stored, transported and working, there is usually a switching process of different pressurizing devices due to the need for changing locations or peripheral auxiliary devices, and there is a risk that the stack will be impacted by changes in pressurizing force during the process. On the other hand, due to the influence of the long-term tightening pressure, the stack composed of multiple components will produce certain plastic deformation. Finally, in the process of changing from room temperature to high temperature, the components of the battery stack will expand to different degrees due to the heat. This high temperature and device deformation also put forward higher requirements for the material selection and functional design of the pressurization device. Therefore, it is of great significance to have a device that can not only meet the requirements of room temperature storage, transportation, and high temperature working state of the battery stack to avoid horizontal thrust and vertical impact, but also has the function of constant pressure regulation.

[0004] In the existing technology, the current fuel cell stack pressurization methods are divided into two methods: self-pressurization and external pressurization. Among them, external pressurization usually uses pressurization parts such as screws or cylinders. In the working state, a connecting rod is used to connect the stress point of the fuel cell stack at the high temperature with the pressurization part at the low temperature. The overall size of the device is large, and the installation space and transportation requirements are high. At the same time, there are problems with heat conduction and sealing difficulties in the components connecting the high temperature and the low temperature, which reduces the system efficiency.

[0005] The self-pressurization method is more compact and does not have the above-mentioned disadvantages. For example, the patent application with publication number CN116565279A discloses a self-pressurization shell for solid oxide fuel cells. This self-pressurization method often places the stack between the upper and lower plates, and uses one or more sets of bolts to fasten the upper and lower plates, so as to transmit the fastening force to the stack, and then combine with the closed side plates to form a closed cavity. The fastening force of the stack is adjusted by the clamping force of the fastener bolts on the upper and lower plates, that is, the size of the clamping force is equivalent to the size of the fastening force. The pressure of the upper and lower plates is adjusted by adjusting the torque of the fastening nut. Its structure is compact, but the fastening method simply selects the fasteners used at room temperature. On the one hand, at room temperature, no adjustment method is provided for the plastic deformation of the stack. On the other hand, it ignores the softening of the fasteners, upper and lower plates, the stack and other important structural parts at high temperatures, the inconsistent thermal expansion coefficients and high temperature creep and many other problems. The rigidly connected structure lacks the ability to adjust. It is difficult to apply a stable pressure to the stack during actual application, increasing the risk of stack leakage or performance degradation. In addition, metals are prone to adhesion under long-term high-temperature conditions, and the above-mentioned device has the disadvantage of being difficult to disassemble after high-temperature operation. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a self-pressurizing device for solid oxide fuel cell stacks, the core of which is to use a specially designed base and pressure plate, with a pressure block, sleeve and other components to provide a constant tightening pressure to the fuel cell stack throughout its life cycle. The device has a compact structure, is easy to install and disassemble, and can be directly used in complex environments such as storage, transportation, and high-temperature operation without any operation after installation, and has high practical value.

[0007] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0008] A self-pressurizing device for a solid oxide fuel cell stack comprises a base, a fuel cell stack, a pressure plate, a ball, a pressure block and a positioning column, wherein one end of the positioning column is connected to the base, and the other end is connected to the pressure block, the fuel cell stack and the pressure plate are arranged between the base and the pressure block, the pressure plate is arranged above the fuel cell stack, and the ball is arranged between the pressure block and the pressure plate.

[0009] As a further technical solution of the present invention: the number of the positioning columns is two, and the two positioning columns are symmetrically distributed on both sides of the battery stack, and the two ends of the positioning columns are respectively perpendicular to the top surface of the base and the bottom surface of the pressing block.

[0010] As a further technical solution of the present invention: a sleeve is installed at one end of the positioning column connected to the pressing block, an external thread is provided on the outer wall of the positioning column close to the sleeve, and a nut is threadedly connected to the positioning column;

[0011] Both sides of the pressure plate are connected to elastic thin plates respectively, and mounting holes are provided on the elastic thin plates. One end of the elastic thin plate is sleeved through the mounting holes at the position where the external threads are provided on the positioning column.

[0012] As a further technical solution of the present invention: there are two nuts on each positioning column, and the two nuts are respectively located on two sides of the elastic thin plate.

[0013] As a further technical solution of the present invention: the inner diameter of the sleeve is larger than the outer diameter of the positioning column and smaller than the outer diameter of the external thread.

[0014] As a further technical solution of the present invention: a seal is provided between the base and the battery stack, and the outer dimension of the seal is the same as the bottom dimension of the battery stack.

[0015] As a further technical solution of the present invention: an insulating plate is arranged between the pressing plate and the fuel cell stack, and the outer dimension of the insulating plate is the same as the top surface dimension of the fuel cell stack.

[0016] As a further technical solution of the present invention: four circular grooves are opened on the top surface of the pressure plate, the ball is placed in each of the circular grooves, the ball contacts the bottom of the pressure block, and the ball transmits the fastening force between the pressure block and the pressure plate.

[0017] As a further technical solution of the present invention: four air pipes are connected to the side of the base, and four air holes respectively connected to the four air pipes are opened at the bottom of the fuel cell stack.

[0018] As a further technical solution of the present invention: the center height of the external thread is the same as the sum of the heights of the seal, the battery stack, and the insulating plate after pressurization.

[0019] In summary, the present invention includes at least one of the following beneficial technical effects:

[0020] 1. The present invention discloses a self-pressurizing device for a solid oxide fuel cell stack. After installation, the device can be placed in a storage environment for a long time. In a transportation environment, the fuel cell stack is always subjected to a constant fastening force. Under the dynamic adjustment of the pressure block, the pressure plate and the ball, even if the pressure block is displaced or vibrated relative to the base, the horizontal force will not be transmitted to the fuel cell stack through the ball. Under high-temperature working conditions, thanks to the design of the pressure plate and the matching clearance of the pressure block, the sleeve and the positioning column, the pressurizing device can adjust the relative spatial position of the combination at any time according to the thickness changes of the fuel cell stack, the insulating plate and the seal, ensuring that the fuel cell stack is still subjected to a constant fastening force from low temperature to high temperature and at long-term high temperature, even if there is a phenomenon of thermal expansion coefficient and high-temperature creep.

[0021] 2. The present invention uses a specially designed base and pressure plate, with a pressure block, sleeve and other components to provide a constant tightening pressure on the stack throughout its life cycle. The device has a compact structure, is easy to install and disassemble, and can be directly used in complex environments such as storage, transportation, and high-temperature operation without any operation after installation, which has high practical value.

[0022] 3. The present invention utilizes a specially designed pressurizing device to cleverly separate the vertical force and the horizontal force, and can isolate the horizontal force on the battery stack while providing a constant vertical tightening force. Therefore, it effectively avoids the displacement of components of the battery stack due to external vibration or inertia factors during transportation, and has a high degree of advancement. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 for Figure 1 A partial enlarged schematic diagram of part A.

[0025] Figure 3 A top view of a platen is shown for the present invention.

[0026] Figure numerals: 1. pressure block; 2. pressure plate; 21. elastic thin plate; 22. circular groove; 3. ball bearing; 4. battery stack; 5. base; 51. positioning column; 52. external thread; 53. air pipe; 6. sleeve; 7. nut; 8. insulating plate; 9. seal. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application; obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application without making creative work are within the scope of protection of the present application.

[0028] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] Embodiment 1:

[0031] Reference Figure 1 , which is a self-pressurizing device for a solid oxide fuel cell stack disclosed in the present invention, comprising a base 5, a fuel cell stack 4, a pressure plate 2, a ball 3, a pressing block 1 and a positioning column 51, one end of the positioning column 51 is connected to the base 5, and the other end is connected to the pressing block 1, the fuel cell stack 4 and the pressure plate 2 are arranged between the base 5 and the pressing block 1, the pressure plate 2 is arranged above the fuel cell stack 4, and the ball 3 is arranged between the pressing block 1 and the pressure plate 2.

[0032] In this embodiment, there are two positioning posts 51 , which are symmetrically distributed on both sides of the battery stack 4 , and both ends of the positioning posts 51 are perpendicular to the top surface of the base 5 and the bottom surface of the pressing block 1 .

[0033] Reference Figure 2 The end of the positioning column 51 connected to the pressure block 1 is installed with a sleeve 6, and the outer wall of the positioning column 51 near the sleeve 6 is provided with an external thread 52, and a nut 7 is threadedly connected to the positioning column 51; the two sides of the pressure plate 2 are respectively connected with elastic thin plates 21, and the elastic thin plates 21 are provided with mounting holes, and one end of the elastic thin plates 21 is sleeved on the position of the positioning column 51 where the external thread 52 is provided through the mounting holes. The center height of the external thread 52 is the same as the sum of the heights of the seal 9, the stack 4, and the insulating plate 8 after pressurization.

[0034] Reference Figure 2, two nuts 7 are arranged on each positioning column 51, and the two nuts 7 are respectively located on both sides of the elastic thin plate 21. The inner diameter of the sleeve 6 is larger than the outer diameter of the positioning column 51 and smaller than the outer diameter of the external thread 52. A seal 9 is arranged between the base 5 and the battery stack 4, and the outer dimension of the seal 9 is the same as the bottom dimension of the battery stack 4. An insulating plate 8 is arranged between the pressure plate 2 and the battery stack 4, and the outer dimension of the insulating plate 8 is the same as the top dimension of the battery stack 4.

[0035] Reference Figure 3 The top surface of the pressing plate 2 is provided with four circular grooves 22, and a ball 3 is placed in each circular groove 22. The ball 3 contacts the bottom of the pressing block 1, and the ball 3 transmits the fastening force between the pressing block 1 and the pressing plate 2. Four air pipes 53 are connected to the side of the base 5, and four air holes connected to the four air pipes 53 are respectively provided at the bottom of the battery stack 4.

[0036] The device is composed of multiple components, including a specially designed base 5, a seal 9, a battery stack 4, a pressure plate 2, a ball 3, a pressure block 1, and a sleeve 6 and a nut 7 from the bottom to the top. Each component is made of a variety of materials and is connected in a relatively fixed spatial relationship. The base 5 is made of a high-temperature resistant alloy, and the upper and lower surfaces have a high degree of parallelism to ensure that the components placed on the base 5 are placed horizontally.

[0037] The upper surface of the base 5 close to the battery stack 4 has a high level of flatness and finish, and two positioning posts 51 are symmetrically designed on the left and right. The positioning post 51 is installed vertically, and some areas thereof are processed with external threads 52. Four air pipes 53 are connected to the side by welding. According to the common structure of the current battery stack 4, four air holes are opened at the bottom of the battery stack 4 for the entry and exit of two gases. The four openings on the upper surface of the base 5 are distributed in the same manner as the four air holes at the bottom of the battery stack 4. Furthermore, the openings are connected to the air pipes 53 in a one-to-one correspondence and are independent of each other. Furthermore, the internal connection of the base 5 can be specially designed to achieve a better distribution effect for the gas entering and exiting.

[0038] A seal 9 is placed between the base 5 and the battery stack 4. The material of the seal 9 can be selected from high-temperature glass or mica sheets, vermiculite sheets, and its outer dimensions are the same as the bottom of the battery stack 4. The inner area of ​​the seal 9 is opened, and the position of the opening is the same as that of the battery stack 4. After installation, the gas entering and exiting the air pipe 53 can enter the battery stack 4 from the bottom opening of the battery stack 4 through the opening of the seal 9. Further, when the position and size of the opening in the inner area of ​​the seal 9 are determined, the outer dimensions of the seal 9 can be reduced. After the size is reduced, the force area of ​​the seal 9 is reduced, and the pressure can be increased under the same pressure condition, which is conducive to reducing the gas leakage rate between the seal 9 and the base 5 and between the seal 9 and the battery stack 4.

[0039] The insulating plate 8 is placed on the upper surface of the battery stack 4, and is usually made of high temperature resistant insulating materials such as alumina and mica. The outer dimensions are the same as those on the upper surface of the battery stack 4, and the upper and lower surfaces of the insulating plate 8 must have high flatness and parallelism.

[0040] The pressure plate 2 is made of high-temperature resistant alloy and has a bilaterally symmetrical structure. The circular spacing of the openings on both sides is the same as that of the positioning column 51, and the size of the opening is larger than the outer diameter of the external thread 52. The thickness consists of two parts. The size of the central area is the same as that of the upper surface of the battery stack 4, and the thickness is thicker. Four circular grooves 22 are processed on the upper surface, and balls 3 are placed in the circular grooves 22. The balls 3 transmit the tightening force between the pressure block 1 and the pressure plate 2. The thicker size in the center of the pressure plate 2 ensures that it is not easy to deform under pressure at high temperatures. The four circular grooves 22 processed on the upper surface of the pressure plate 2 are used to limit the displacement of the balls 3 so that the balls 3 are always in a position close to the center of the pressure plate 2. Elastic thin plates 21 are connected to both sides of the pressure plate 2, and holes are punched on the elastic thin plates 21. The elastic thin plates 21 are thin in the vertical direction and are prone to elastic deformation after being subjected to force. They have a wider thickness in the horizontal direction and are not easy to deform.

[0041] The center height of the external thread 52 should be the same as the sum of the heights of the seal 9, the battery stack 4, and the insulating plate 8 after pressurization, and the total processing height of the external thread 52 in the vertical direction should be greater than the sum of the superimposed thickness of the thinner part of the pressure plate 2 and the two nuts 7.

[0042] The nut 7 is made of high temperature alloy, and has an internal thread that matches the external thread 52. The major diameter of the external thread 52 needs to be larger than the diameter of the positioning column 51 to ensure that the nut 7 can be installed in conjunction with the external thread 52 in the middle of the positioning column 51. The sleeve 6 is made of ceramic or mica, and has a through hole inside. The inner diameter is larger than the outer diameter of the positioning column 51 and smaller than the outer diameter of the external thread 52. The sleeve 6 is easy to install on the positioning column 51, and is placed above the external thread 52 to fix the position.

[0043] The pressing block 1 is made of high temperature alloy, and has through holes symmetrically opened on the left and right sides, the spacing between the openings is the same as that of the positioning column 51, and the size of the openings is larger than the outer diameter of the sleeve 6. The pressing block 1 is easy to be installed above the entire pressurizing device, and the lower surface contacts the ball 3, and cooperates with the positioning column 51 installed with the sleeve 6 through the through holes on both sides.

[0044] In the above device, the tightening force on the battery stack 4 is equivalent to the gravity of the pressing block 1. When the gravity is constant, the tightening force is constant. The gravity is mainly determined by the volume and density of the pressing block 1, and can be easily measured accurately by a gravimeter. By appropriately adjusting the thickness of the pressing block 1 according to the required force, the volume can be adjusted, thereby controlling the tightening force on the battery stack 4.

[0045] In the above device, the battery stack 4 is located in the central area, and the tightening force is controlled by the gravity of the pressure block 1 and can be kept constant. The pressure block 1, the positioning column 51, and the sleeve 6 of the device adopt interference fit, which is convenient for installation and disassembly. And the sleeve 6 and the pressure block 1, the positioning column 51 are not easy to be bonded due to the gap and the selection of different materials, so that the upper pressure structure is in a sliding and adjustable state. The insulating plate 8 is fixed to the positioning column 51 by four nuts 7. The deformation is easy to occur in the vertical direction, but not in the horizontal direction. When the pressure block 1 is vibrated or inertially displaced horizontally, it drives the ball 3 to roll in the horizontal direction. Since the pressure plate 2 and the positioning column 51 are relatively fixed, the ball 3 and the battery stack 4 under the pressure plate 2 are always subjected to the tightening force in the vertical direction, and are not subjected to the force in the horizontal direction. On the other hand, when the battery stack 4 is squeezed by constant force and plastic deformation occurs, the pressure plate 2 produces elastic deformation in the vertical direction, and the position of the central area of ​​the pressure plate 2 is adjusted downward to ensure that the force on the battery stack 4 is constant. Similarly, when changing from low temperature to high temperature, such as due to thermal expansion or high temperature creep, the height of the ball 3, the battery stack 4, and the seal 9 increases or decreases, and the central area of ​​the pressure plate 2 can be adjusted at any time to ensure that the fastening force on the battery stack 4 is constant.

[0046] Preferably, the fastening method of the nut 7 and the pressing plate 2 on the external thread 52 can be double nut 7 fastening, which reduces the impact of vibration and reduces the fastening force of the nut 7. Furthermore, before the nut 7 and the external thread 52 are fastened, boron nitride or ceramic powder can be coated on the surface of the external thread 52 to prevent the nut 7 and the external thread 52 from bonding under high temperature and high pressure, so as to facilitate the disassembly of the device.

[0047] The components included in the device are easy to install and disassemble, and have a compact structure. They can ensure that the battery stack 4 is subjected to a constant tightening pressure in various conditions of storage, transportation, and operation. At the same time, the specially designed pressurizing structure prevents the battery stack 4 from being subjected to horizontal forces, ensuring that the structure of the battery stack 4 is intact and reliable.

[0048] Implementation method: the base 5 is placed on a horizontal plane; the seal 9 is placed on the upper surface of the base 5 to ensure that the opening of the seal 9 is aligned with the base 5; the two nuts 7 are respectively screwed into the external thread 52 until the edge of the lower area of ​​the external thread 52; the battery stack 4, the insulating plate 8, and the pressure plate 2 are sequentially stacked on the seal 9 to ensure that the above components are all at the same vertical center; the ball 3 is placed in the center of the groove of the pressure plate 2; the two nuts 7 are respectively screwed into the external thread 52 until the edge of the upper area of ​​the external thread 52; the two sleeves 6 are respectively inserted into the positioning column 51. Since the inner diameter of the sleeve 6 is smaller than the major diameter of the external thread 52, the sleeve 6 can be stably placed on the external thread 52; the pressure block 1 is installed so that the through holes on both sides of the pressure block 1 are inserted into the sleeve 6. At this time, the tightening force on the battery stack 4 is equivalent to the gravity of the pressure block 1. The insulating plate 8, the battery stack 4, and the seal 9 are under a preset pressure and deformed to a certain extent; the relative positions of the thin plates on both sides of the pressing plate 2 and the external threads 52 are ensured to remain unchanged, and the two pairs of nuts 7 on the upper and lower sides of the pressing plate 2 are tightened. At this time, the relative position of the pressing plate 2 relative to the external threads 52 remains unchanged. Obviously, the relative position of the pressing plate 2 relative to the base 5 remains unchanged. The special shape design of the pressing plate 2 allows the pressing plate 2 to undergo elastic deformation in the vertical direction when subjected to a relatively small vertical force, but is unlikely to undergo deformation or displacement relative to the base 5 when subjected to a relatively large horizontal force.

[0049] The implementation principle of the present invention is as follows: the present invention discloses a self-pressurizing device for a solid oxide fuel cell stack, and the device can be placed in a storage environment for a long time after installation; in a transportation environment, the fuel cell stack 4 is always subjected to a constant fastening force, and under the dynamic adjustment of the pressure block 1, the pressure plate 2 and the ball 3, even if the pressure block 1 is displaced or vibrated relative to the base 5, the horizontal force will not be transmitted to the fuel cell stack 4 through the ball 3; under high-temperature working conditions, thanks to the design of the pressure plate 2 and the matching clearance of the pressure block 1, the sleeve 6, and the positioning column 51, the pressurizing device can adjust the relative spatial position of the combination at any time according to the thickness changes of the fuel cell stack 4, the insulating plate 8, and the seal 9, to ensure that the fuel cell stack 4 is still subjected to a constant fastening force from low temperature to high temperature and long-term high temperature, even if there are thermal expansion coefficients and high-temperature creep phenomena.

[0050] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-pressurizing device for a solid oxide fuel cell stack, characterized in that: The invention comprises a base (5), a battery stack (4), a pressure plate (2), a ball (3), a pressure block (1) and a positioning column (51), wherein one end of the positioning column (51) is connected to the base (5), and the other end is connected to the pressure block (1); the battery stack (4) and the pressure plate (2) are arranged between the base (5) and the pressure block (1); the pressure plate (2) is arranged above the battery stack (4); and the ball (3) is arranged between the pressure block (1) and the pressure plate (2).

2. A self-pressurizing device for a solid oxide fuel cell stack according to claim 1, characterized in that: The positioning columns (51) are configured in two, and the two positioning columns (51) are symmetrically distributed on both sides of the battery stack (4), and the two ends of the positioning columns (51) are respectively perpendicular to the top surface of the base (5) and the bottom surface of the pressing block (1).

3. A self-pressurizing device for a solid oxide fuel cell stack according to claim 2, characterized in that: A sleeve (6) is installed at one end of the positioning column (51) connected to the pressing block (1); an external thread (52) is provided on the outer wall of the positioning column (51) close to the sleeve (6); and a nut (7) is threadedly connected to the positioning column (51); The two sides of the pressure plate (2) are respectively connected to elastic thin plates (21), and a mounting hole is provided on the elastic thin plate (21). One end of the elastic thin plate (21) is sleeved through the mounting hole at the position where the positioning column (51) is provided with the external thread (52).

4. A self-pressurizing device for a solid oxide fuel cell stack according to claim 3, characterized in that: There are two nuts (7) on each positioning column (51), and the two nuts (7) are respectively located on two sides of the elastic thin plate (21).

5. The self-pressurizing device for a solid oxide fuel cell stack according to claim 3, characterized in that: The inner diameter of the sleeve (6) is larger than the outer diameter of the positioning column (51) and smaller than the outer diameter of the external thread (52).

6. A self-pressurizing device for a solid oxide fuel cell stack according to claim 1, characterized in that: A sealing member (9) is provided between the base (5) and the cell stack (4), and the outer dimensions of the sealing member (9) are the same as the bottom dimensions of the cell stack (4).

7. A self-pressurizing device for a solid oxide fuel cell stack according to claim 1, characterized in that: An insulating plate (8) is provided between the pressing plate (2) and the cell stack (4), and the outer dimensions of the insulating plate (8) are the same as the top surface dimensions of the cell stack (4).

8. The self-pressurizing device for a solid oxide fuel cell stack according to claim 1, characterized in that: The top surface of the pressure plate (2) is provided with four circular grooves (22), and the ball (3) is placed in each of the circular grooves (22). The ball (3) is in contact with the bottom of the pressure block (1), and the ball (3) transmits the tightening force between the pressure block (1) and the pressure plate (2).

9. A self-pressurizing device for a solid oxide fuel cell stack according to claim 1, characterized in that: Four air pipes (53) are connected to the side of the base (5), and four air holes respectively connected to the four air pipes (53) are provided at the bottom of the battery stack (4).

10. The self-pressurizing device for a solid oxide fuel cell stack according to claim 3, characterized in that: The center height of the external thread (52) is the same as the sum of the heights of the sealing member (9), the battery stack (4), and the insulating plate (8) after pressurization.

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