Proton exchange membrane hydrogen production electrolytic cell self-balancing sealing structure with annular positioning end and integrated injection molding method

Abstract

The invention relates to a proton exchange membrane hydrogen production electrolytic cell self-balancing sealing structure with an annular positioning end and an integrated injection molding method, the proton exchange membrane hydrogen production electrolytic cell self-balancing sealing structure comprises an anode plate, a cathode plate, a membrane electrode assembly and a sealing element, the membrane electrode assembly and the sealing element are connected and fixed through a sealing element MEA positioning groove, and the membrane electrode assembly and the sealing element are arranged between the anode plate and the cathode plate; in the sealing element, the elastic positioning end unit of the sealing element is in contact with the sealing grooves in the anode plate and the cathode plate to form a sealing interface; and the sealing element self-adaptive pressure adjusting unit is a C-shaped unit which elastically deforms according to the pressure change. When the air pressure difference is larger, the elastic bending of the sealing element self-adaptive pressure adjusting unit is larger, the contact stress between the sealing element elastic positioning end unit and the groove wall of the sealing groove is larger, and the sealing interface is also larger. Compared with the prior art, the invention has the advantages of uniform stress distribution, long service life, high production efficiency and the like.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production electrolyzers, and in particular to a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end and an integral injection molding method. Background Art

[0002] As the global carbon neutrality goal is promoted, hydrogen energy has attracted much attention as an important part of the future clean energy system. Compared with "grey hydrogen" and "blue hydrogen", "green hydrogen" produces hydrogen through water electrolysis and relies on renewable energy to achieve zero carbon emissions in the production process. It is a truly clean and sustainable form of energy.

[0003] In the "green hydrogen" production technology, the proton exchange membrane hydrogen production electrolyzer has become an important technical path to promote the large-scale application of "green hydrogen" due to its advantages such as high efficiency, low energy consumption and modular design. Large-format metal plates, multi-layer polymer membrane electrodes and precision assembly seals are the core components of the proton exchange membrane hydrogen production electrolysis single cell. In order to meet the hydrogen production rate and hydrogen storage efficiency, high-pressure and high-pressure difference hydrogen and oxygen are distributed on both sides of the multi-layer polymer membrane electrode. When multiple single cells are precisely aligned and stacked, the large-format metal plates and high-pressure gas jointly compress the seals to form a static sealing system for high-power proton exchange membrane hydrogen production electrolyzers.

[0004] At present, the performance of the sealing system of the proton exchange membrane hydrogen production electrolyzer mainly depends on the contact stress and contact area of ​​the O-shaped rubber ring after being compressed. In the above structure, in order to ensure that the proton exchange membrane hydrogen production electrolyzer still has good sealing performance under the highest working gas pressure, the O-shaped rubber ring is subjected to high compression load for a long time. In the complex internal environment of the hydrogen production electrolyzer, the seals with high compression rates are very prone to stress relaxation. Under the superimposed influence of assembly deviations, the unevenness of the contact stress of the sealing interface on the seal is further expanded, which accelerates the stress relaxation of the seal, causing the sealing performance to drop rapidly during the long-term operation of the electrolyzer, thereby affecting the normal use of the proton exchange membrane hydrogen production electrolyzer, and even causing major safety issues such as combustion and explosion. Therefore, how to make the seal evenly distributed in stress, ensure sealing performance and extend service life under the condition of being able to withstand high pressure is a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end and an integrated injection molding method. The sealing interface and contact stress are changed by adaptive elastic deformation of the seal under different air pressure differences, thereby achieving the effect of uniform stress distribution and shortening the time that the seal is under high compression conditions.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] According to one aspect of the present invention, there is provided a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end, comprising an anode plate, a cathode plate, a membrane electrode assembly and a seal, wherein the membrane electrode assembly and the seal are connected and fixed via a seal MEA positioning groove and are arranged between the anode plate and the cathode plate; in the seal, the seal elastic positioning end unit contacts the sealing grooves on the anode plate and the cathode plate to form a sealing interface; the seal adaptive pressure regulating unit is a C-shaped unit that undergoes elastic deformation according to pressure changes.

[0008] Furthermore, when the seal is subjected to an external pre-compression load, the seal's adaptive pressure regulating unit performs adaptive elastic bending, so that contact stress is generated between the seal's elastic positioning end unit and the seal groove bottom, thereby forming a sealing interface; when the seal is subjected to the combined action of an external pre-compression load and internal air pressure, the seal's adaptive pressure regulating unit performs adaptive further elastic bending according to the air pressure difference, so that contact stress is generated between the seal's elastic positioning end unit and the seal groove wall, thereby forming a sealing interface.

[0009] Furthermore, the greater the air pressure difference is, the greater the elastic bending of the adaptive pressure regulating unit of the seal is, the greater the contact stress between the elastic positioning end unit of the seal and the wall of the sealing groove is, and the larger the sealing interface is.

[0010] Furthermore, the anode plate is provided with a plurality of fluid cavities, including an anode plate water inlet, an anode plate water outlet and an anode plate hydrogen inlet; the cathode plate is provided with a plurality of fluid cavities, including a cathode plate hydrogen outlet and a cathode plate water inlet.

[0011] Furthermore, sealing grooves are provided around the fluid cavity opening, including an anode plate water inlet sealing groove, an anode plate water outlet sealing groove, an anode plate hydrogen port sealing groove, a cathode plate hydrogen outlet sealing groove and a cathode plate water port sealing groove; and an anode plate outer ring sealing groove is provided around the edge of the anode plate; and a cathode plate outer ring sealing groove is provided around the edge of the cathode plate.

[0012] Furthermore, the sealing element comprises an outer ring sealing element, a hydrogen port sealing element and a water port sealing element.

[0013] Furthermore, the membrane electrode assembly consists of a gas diffusion layer, a proton exchange membrane, a catalyst coating and a membrane electrode frame.

[0014] According to another aspect of the present invention, a one-piece injection molding method of a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end is provided, and the specific steps include:

[0015] S1, according to the shapes of the sealing elastic positioning end unit, the sealing adaptive pressure regulating unit and the sealing groove, obtain a first assembly mold, a second assembly mold, a third assembly mold, a fourth assembly mold and a fifth assembly mold;

[0016] S2, assembling the mold and the membrane electrode assembly to form a cavity in the shape of a seal;

[0017] S3, heating the mold, injecting the liquid rubber into the cavity through the mold gate located on the first assembly mold, and performing vulcanization treatment;

[0018] S4. Wait for the liquid rubber to cool to room temperature and remove the mold to form an integrated component of the seal and the membrane electrode assembly.

[0019] Furthermore, the assembly sequence in S2 is to first clamp the membrane electrode frame by the fourth assembly mold and the fifth assembly mold; splice the second assembly mold with the fourth assembly mold through the positioning surface, and splice the third assembly mold with the fifth assembly mold through the positioning surface; finally, splice the first assembly mold with the second assembly mold.

[0020] Furthermore, the injection temperature of the sealing material is lower than the melting point of the membrane electrode assembly.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) Uniform stress distribution: By tightly combining the seal with the membrane electrode assembly and fixing them by one-piece injection molding, the gaps or deviations that may occur in traditional assembly are eliminated, so that the seal and the membrane electrode assembly can be accurately aligned and fixed, thereby avoiding uneven stress caused by slight assembly errors between components. At the same time, the seal can automatically ensure correct positioning without relying on external tools or auxiliary devices, and rely on adaptive elastic deformation to avoid stress concentration or uneven stress caused by assembly errors, making the stress distribution of the entire seal more uniform.

[0023] (2) Extending the service life of seals: The structure of the seal can dynamically adjust its shape according to the adaptive pressure, and thus adjust the contact state of the sealing interface under different air pressure differences. The contact stress between the elastic positioning end unit of the seal and the wall of the sealing groove is dynamically adjusted as the air pressure difference changes, effectively shortening the time that the seal is in high compression conditions, effectively preventing the problem of stress relaxation caused by long-term high compression, and extending the service life of the seal.

[0024] (3) Improving the efficiency of manufacturing hydrogen-producing electrolyzers: In the process of manufacturing seals, the membrane electrode assembly and the seals are injection molded as one piece, eliminating the assembly steps between the preformed seals and the membrane electrode assembly in the traditional process, reducing the process flow of manufacturing hydrogen-producing electrolyzers, lowering the assembly precision requirements, and improving manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A diagram of a self-balancing seal structure of a proton exchange membrane hydrogen production electrolyzer having an annular positioning end;

[0026] Figure 2 It is a top view of the anode plate side;

[0027] Figure 3 It is a top view of the cathode plate side;

[0028] Figure 4 This is the equivalent stress cloud diagram of the numerical simulation under the action of pre-compression load;

[0029] Figure 5 This is the equivalent stress cloud diagram of the numerical simulation under the combined effect of the pre-compression load and the internal air pressure;

[0030] Figure 6 It is a schematic diagram of assembling the mold and membrane electrode assembly in one-piece injection molding;

[0031] Figure 7 This is a schematic diagram of liquid rubber being injected into a mold during one-piece injection molding;

[0032] Figure 8 Structural diagram of the integral injection molding of the seal and membrane electrode assembly.

[0033] Explanation of the numbers in the figure: 1. Anode plate; 11. Anode plate outer ring sealing groove; 12. Anode plate water inlet sealing groove; 13. Anode plate water outlet sealing groove; 14. Anode plate hydrogen inlet sealing groove; 2. Cathode plate; 21. Cathode plate outer ring sealing groove; 22. Cathode plate hydrogen outlet sealing groove; 23. Cathode plate water inlet sealing groove; 3. Membrane electrode assembly; 4. Seal; 41. Seal MEA positioning groove; 42. Seal adaptive pressure regulating unit; 43. Seal elastic positioning end unit; 51. First assembly mold; 52. Second assembly mold; 53. Third assembly mold; 54. Fourth assembly mold; 55. Fifth assembly mold; 511. Mold gate. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end is shown. Figure 2 It is the top view of the anode plate. Figure 3 It is a top view of the cathode plate. The self-balancing sealing structure of the hydrogen production electrolyzer includes an anode plate 1, a cathode plate 2, a membrane electrode assembly 3 and a seal 4. The membrane electrode assembly 3 and the seal 4 are connected and fixed through the seal MEA positioning groove 41, and are arranged between the anode plate 1 and the cathode plate 2; in the seal 4, the seal elastic positioning end unit 43 contacts the sealing grooves on the anode plate 1 and the cathode plate 2 to form a sealing interface; the seal adaptive pressure regulating unit 42 is a C-shaped unit that undergoes elastic deformation according to pressure changes. The seal 4 is a gasket made of an electrically insulating rubber-like elastic polymer material, such as EPDM rubber.

[0036] like Figure 4 As shown, when the seal 4 is subjected to an external pre-compression load, the seal adaptive pressure regulating unit 42 is adaptively elastically bent, so that contact stress is generated between the seal elastic positioning end unit 43 and the bottom of the sealing groove, forming a sealing interface. Figure 5 As shown, when the seal 4 is subjected to the combined effect of the external pre-compression load and the internal air pressure, the seal adaptive pressure regulating unit 42 is further elastically bent adaptively according to the air pressure difference, so that contact stress is generated between the seal elastic positioning end unit 43 and the sealing groove wall, forming a sealing interface. The greater the air pressure difference, the greater the elastic bending of the seal adaptive pressure regulating unit 42, the greater the contact stress between the seal elastic positioning end unit 43 and the sealing groove wall, and the larger the sealing interface. Through the C-shaped unit of the seal adaptive pressure regulating unit 42, the maximum contact stress and contact area on the sealing interface are dynamically adjusted in real time with different air pressure differences, which alleviates the stress relaxation of the seal under long-term high compression conditions and improves the service life of the hydrogen production electrolyzer sealing system.

[0037] Depend on Figure 2 It can be seen that the anode plate 1 is provided with a plurality of fluid cavities, including an anode plate water inlet, an anode plate water outlet and two anode plate hydrogen inlets. Figure 3 It can be seen that a plurality of fluid cavities are provided on the cathode plate 2, including two cathode plate hydrogen outlets and two cathode plate water outlets.

[0038] The circumference of the fluid cavity is provided with sealing grooves, including anode plate water inlet sealing groove 12, anode plate water outlet sealing groove 13, anode plate hydrogen port sealing groove 14, cathode plate hydrogen outlet sealing groove 22 and cathode plate water port sealing groove 23; and an anode plate outer ring sealing groove 11 is provided on the edge circumference of the anode plate 1; a cathode plate outer ring sealing groove 21 is provided on the edge circumference of the cathode plate 2. The sealing grooves are not connected to each other, and the positions of the sealing grooves on the anode plate 1 and the sealing grooves on the cathode plate 2 correspond one by one. The sealing members 4 are all swept annular structures, contacting the inner wall of the sealing groove. The sealing members 4 include outer ring seals, hydrogen port seals and water port seals.

[0039] The membrane electrode assembly 3 is composed of a gas diffusion layer, a proton exchange membrane, a catalyst coating and a membrane electrode frame.

[0040] like Figure 6 , Figure 7 and Figure 8 As shown, it is an integral injection molding method of a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end, and the specific steps include:

[0041] S1, according to the shapes of the sealing elastic positioning end unit 43, the sealing adaptive pressure regulating unit 42 and the sealing groove, obtain the first assembly mold 51, the second assembly mold 52, the third assembly mold 53, the fourth assembly mold 54 and the fifth assembly mold 55;

[0042] S2, assembling the mold and the membrane electrode assembly 3 to form a cavity in the shape of the seal 3;

[0043] S3, heating the mold to 80 degrees Celsius, injecting liquid EPDM rubber at a temperature of 180 degrees Celsius into the cavity through the mold gate 511 located on the first assembly mold 51 at a pressure of 800 bar, and performing a vulcanization treatment for 10 minutes. The injection temperature of the sealing material is lower than the melting point of the membrane electrode assembly 3, and the sealing material can be selected from polyphenylene sulfide with a melting point of 280 degrees Celsius;

[0044] S4, waiting for the liquid rubber to cool to room temperature, removing the mold, and forming an integrated component of the seal 4 and the membrane electrode assembly 3.

[0045] Depend on Figure 6 It can be seen that the assembly sequence in S2 is to first clamp the membrane electrode assembly 3 through the fourth assembly mold 54 and the fifth assembly mold 55; splice the second assembly mold 52 with the fourth assembly mold 54 through the positioning surface, and splice the third assembly mold 53 with the fifth assembly mold 55 through the positioning surface; finally, splice the first assembly mold 51 with the second assembly mold 52.

[0046] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end, comprising an anode plate (1), a cathode plate (2), a membrane electrode assembly (3) and a sealing member (4), characterized in that: The membrane electrode assembly (3) and the seal (4) are connected and fixed via a seal MEA positioning groove (41), and are arranged between the anode plate (1) and the cathode plate (2); in the seal (4), a seal elastic positioning end unit (43) contacts the sealing grooves on the anode plate (1) and the cathode plate (2) to form a sealing interface; and the seal adaptive pressure regulating unit (42) is a C-shaped unit that undergoes elastic deformation according to pressure changes.

2. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 1, characterized in that: When the seal (4) is subjected to an external pre-compression load, the seal adaptive pressure regulating unit (42) is adaptively elastically bent, so that contact stress is generated between the seal elastic positioning end unit (43) and the bottom of the sealing groove, thereby forming a sealing interface; when the seal (4) is subjected to the combined action of the external pre-compression load and the internal air pressure, the seal adaptive pressure regulating unit (42) is adaptively further elastically bent according to the air pressure difference, so that contact stress is generated between the seal elastic positioning end unit (43) and the wall of the sealing groove, thereby forming a sealing interface.

3. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 2, characterized in that: The greater the air pressure difference, the greater the elastic bending of the sealing member adaptive pressure regulating unit (42), the greater the contact stress between the sealing member elastic positioning end unit (43) and the sealing groove wall, and the larger the sealing interface.

4. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 1, characterized in that: The anode plate (1) is provided with a plurality of fluid cavities, including an anode plate water inlet, an anode plate water outlet and an anode plate hydrogen inlet; the cathode plate (2) is provided with a plurality of fluid cavities, including a cathode plate hydrogen outlet and a cathode plate water inlet.

5. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 4, characterized in that: The fluid cavity opening is provided with sealing grooves in the circumference thereof, including an anode plate water inlet sealing groove (12), an anode plate water outlet sealing groove (13), an anode plate hydrogen outlet sealing groove (14), a cathode plate hydrogen outlet sealing groove (22) and a cathode plate water outlet sealing groove (23); and an anode plate outer ring sealing groove (11) is provided in the circumference of the edge of the anode plate (1); and a cathode plate outer ring sealing groove (21) is provided in the circumference of the edge of the cathode plate (2).

6. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 1, characterized in that: The sealing element (4) comprises an outer ring sealing element, a hydrogen port sealing element and a water port sealing element.

7. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 1, characterized in that: The membrane electrode assembly (3) consists of a gas diffusion layer, a proton exchange membrane, a catalyst coating and a membrane electrode frame.

8. An integral injection molding method for a self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end as claimed in any one of claims 1 to 9, characterized in that: The specific steps include: S1, obtaining a first assembly mold (51), a second assembly mold (52), a third assembly mold (53), a fourth assembly mold (54) and a fifth assembly mold (55) according to the shapes of the sealing elastic positioning end unit (43), the sealing adaptive pressure adjustment unit (42) and the sealing groove; S2, assembling the mold and the membrane electrode assembly (3) to form a cavity in the shape of the seal (3); S3, heating the mold, injecting the liquid rubber into the cavity through the mold gate (511) located on the first assembly mold (51), and performing a vulcanization treatment; S4, waiting for the liquid rubber to cool to room temperature, removing the mold, and forming an integrated component of the seal (4) and the membrane electrode assembly (3).

9. The one-piece injection molding method of the self-balancing sealing structure of the proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 8, characterized in that: The assembly sequence in S2 is: first, clamp the membrane electrode assembly (3) by the fourth assembly mold (54) and the fifth assembly mold (55); splice the second assembly mold (52) with the fourth assembly mold (54) through the positioning surface, and splice the third assembly mold (53) with the fifth assembly mold (55) through the positioning surface; and finally, splice the first assembly mold (51) with the second assembly mold (52).

10. The self-balancing sealing structure of a proton exchange membrane hydrogen production electrolyzer with an annular positioning end according to claim 8, characterized in that: The injection molding temperature of the sealing material is lower than the melting point of the membrane electrode assembly (3).

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