Framework rubber sealing device for electrochemical system

Abstract

The invention discloses a framework rubber sealing device for an electrochemical system. The framework rubber sealing device comprises a sealing part main body (1) and a framework (2), the sealing part is characterized in that the sealing part main body (1) is provided with a first sealing surface (10) and a second sealing surface (11) which are parallel to each other and are opposite to each other along a first direction; and the framework (2) is strip-shaped, is arranged in the sealing part main body (1), and is not in direct contact with the first sealing surface (10) and the second sealing surface (11).

Description

Technical Field

[0001] This application relates to the technical field of sealing materials, and particularly to a framework rubber sealing device for an electrochemical system. Background Art

[0002] Different electrolysis systems have different pressure requirements. For example, the operating pressure of an alkaline electrolyzer is usually relatively low (e.g., 10 - 20 MPa), while the operating pressure of some proton exchange membrane (PEM) electrolyzers is relatively high (e.g., up to 70 MPa). In electrolyzers that require a relatively high operating pressure, polytetrafluoroethylene (PTFE) has become the preferred choice for electrolysis seals due to its excellent properties. PTFE can withstand common strong acids, strong bases, and oxidants in electrolytes, can also reduce friction between components, reduce wear, and remain stable within a relatively large temperature range encountered in electrolysis systems.

[0003] Although PTFE has excellent properties, it also has some disadvantages: compared with other elastomers, the production of PTFE requires a large amount of energy and is costly; over time, PTFE will deform under a constant pressure, thus affecting the integrity of the seal; PTFE is a persistent organic pollutant (POP), which has attracted attention to its environmental impact.

[0004] The European Chemicals Agency (ECHA) has proposed to restrict certain per- and polyfluoroalkyl substances (PFAS), including some PFAS used in the production of PTFE, which may lead to the prohibition of PTFE. Although silicone rubber and ethylene propylene diene monomer (EPDM) are common in fuel cells, whether they are suitable for electrolysis seals depends on the specific system and pressure requirements. Some high-performance silicone rubbers can withstand pressures up to 50 MPa and are thus suitable for certain electrolysis systems. However, their chemical resistance may not be as good as that of PTFE. Silicone rubber will shrink at sub-zero temperatures, thus reducing the internal stress and contact pressure and increasing the risk of leakage. The pressure limit of EPDM is usually relatively low (about 20 MPa) and may not be an ideal choice for high-pressure electrolysis systems. However, it has good chemical resistance and is a more cost-effective choice than PTFE. Summary of the Invention

[0005] In an electrolyzer environment that requires a relatively high operating pressure, for a sealing material, the key issue is how to provide the required contact pressure before reaching the failure limit of the sealing material. This application provides a design that utilizes silicone rubber or EPDM and makes it suitable for electrolyzers that require a relatively high operating pressure.

[0006] This application discloses a framework rubber sealing device for an electrochemical system, and the framework rubber sealing device includes a sealing part main body and a framework;

[0007] Characterized in that,

[0008] The main body of the sealing part has a first sealing surface and a second sealing surface that are parallel to each other and opposite to each other in the first direction; and

[0009] The skeleton is strip-shaped and is arranged in the main body of the sealing part without directly contacting the first sealing surface and the second sealing surface.

[0010] In the skeleton rubber sealing device for an electrochemical system according to the present application, a skeleton made of a mechanically rigid material such as metal or carbon fiber is inserted inside the main body of the sealing part made of silicone rubber and EPDM, or a skeleton made of silicone rubber and EPDM with a hardness higher than that of the main body of the sealing part is inserted to form a skeleton rubber structure.

[0011] The skeleton rubber sealing device for an electrochemical system according to the present application is optionally provided with a convex structure on one side to reduce the possibility of the skeleton being pierced due to defects in the manufacturing process.

[0012] The skeleton rubber sealing device for an electrochemical system according to the present application is optionally provided with convex structures on both sides to provide symmetric contact pressure. Brief Description of the Drawings

[0013] The foregoing and other aspects of the present application can be more comprehensively understood from the following detailed description in conjunction with the accompanying drawings below. It should be noted that the scales of the respective drawings may be different for the purpose of clear illustration, but this will not affect the understanding of the present application.

[0014] Figure 1 A cross-sectional view showing a skeleton rubber sealing device for an electrochemical system according to a first embodiment of the present application.

[0015] Figure 2 Showing Figure 1 A partial cross-sectional view of the skeleton rubber sealing device for an electrochemical system.

[0016] Figure 3 A partial cross-sectional view showing a skeleton rubber sealing device for an electrochemical system according to a second embodiment of the present application.

[0017] Figure 4 A partial cross-sectional view showing a skeleton rubber sealing device for an electrochemical system according to a third embodiment of the present application.

[0018] Figure 5 A partial cross-sectional view showing a skeleton rubber sealing device for an electrochemical system according to a fourth embodiment of the present application.

[0019] Figure 6 A cross-sectional view showing a skeleton rubber sealing device for an electrochemical system according to other embodiments of the present application. Detailed Embodiments

[0020] Exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be fully conveyed to those skilled in the art. It should be noted that the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" and "several" is two or more, unless otherwise specifically defined.

[0021] Figure 1 A cross-sectional view of a frame rubber sealing device for an electrochemical system according to a first embodiment of the present application is shown. The frame rubber sealing device can have various planar shapes, for example, in the first embodiment, it has a planar shape combining a rectangle and a hollow square for sealing in a fuel cell. In other embodiments, the frame rubber sealing device can also have an annular or other planar shapes, such as an ellipse or a rectangle. Hereinafter, the mutually perpendicular directions in the main extension plane of the frame rubber sealing device are set as the transverse direction x and the longitudinal direction y, and the direction perpendicular to the main extension plane of the frame rubber sealing device is set as the vertical direction z.

[0022] The frame rubber sealing device includes a sealing portion main body 1 and a frame 2. The frame 2 is strip-shaped and is disposed in the sealing portion main body 1. The cross-section of the sealing portion main body 1 along the vertical direction z is generally rectangular. The sealing surfaces (contact surfaces) of the frame rubber sealing device are the top surface and the bottom surface along the vertical direction z.

[0023] Figure 2 Shown Figure 1Partial cross-sectional view of the skeleton rubber sealing device. The sealing portion main body 1 has a first sealing surface 10 and a second sealing surface 11 that are parallel to each other and opposite to each other along the vertical direction z. The skeleton 2 has a circular cross-sectional shape and is disposed in the sealing portion main body 1 at a distance approximately equal from the first sealing surface 10 and the second sealing surface 11. The sealing portion main body 1 includes a first protrusion portion 12 at a position corresponding to the skeleton 2 on the first sealing surface 10. In other words, the first protrusion portion 12 is arranged on the first sealing surface 10 in the same pattern as the planar pattern of the skeleton 2. It should be noted that the distances of the skeleton 2 from the first sealing surface 10 and the second sealing surface 11 may not be equal, for example, closer to the first sealing surface 10 or closer to the second sealing surface 11, as long as the skeleton 2 does not directly contact the first sealing surface 10 and the second sealing surface 11, in order to avoid leakage at the interface.

[0024] In the first embodiment, the main pressure-bearing parts of the skeleton rubber sealing device are the second sealing surface 11 and the first protrusion portion 12 on the first sealing surface 10. The sealing portion main body 1 is made of silicone rubber or EPDM, while the skeleton 2 is made of silicone rubber or EPDM with a hardness higher than that of the sealing portion main body 1, or made of metal or carbon fiber material. It should be noted that the skeleton rubber sealing device is manufactured by a molding process instead of the currently commonly used injection molding process. The reason for using the molding process is that in the molding process, a configuration of two molds, three molds, or more molds can be adopted. The skeleton 2 is placed in the corresponding mold, and then the mold is closed and vulcanized. Compared with the injection molding process commonly used in the prior art, it is easier to position the skeleton 2 at the specified position in the sealing portion main body 1 in the molding process. In addition, different from some solutions in the prior art, neither the sealing portion main body 1 nor the skeleton 2 uses fluororubber. The sealing portion main body 1 is made of silicone rubber or EPDM instead of fluororubber (such as PTFE), which is beneficial to environmental protection. The results of simulation (such as finite element analysis) show that the contact pressure of the second sealing surface 11 (before reaching the failure limit) is about twice that of a traditional sealing device with the same sealing width (distance along the vertical direction z), while the contact pressure of the first sealing surface 10 is greater, almost four times that of a traditional sealing device with the same sealing width.

[0025] Figure 3A partial cross-sectional view of a skeleton rubber sealing device for an electrochemical system according to a second embodiment of the present application is shown. Compared with the first embodiment, in the second embodiment, the sealing portion main body 1 includes a second protruding portion 13 at a position corresponding to the skeleton 2 on the second sealing surface 11. In other words, the first protruding portion 12 and the second protruding portion 13 of the sealing portion main body 1 are mirror-symmetrical about a middle plane parallel to and equidistant from the first sealing surface 10 and the second sealing surface 11. This mirror-symmetrical design of the second embodiment is considered because in the first embodiment, the pressure distributions on the first sealing surface 10 and the second sealing surface 11 are asymmetric. In other words, at a small compression ratio, there is a risk of leakage at the second sealing surface 11, while at a large compression ratio, there is a risk of failure at the first sealing surface 10.

[0026] Figure 4 A partial cross-sectional view of a skeleton rubber sealing device for an electrochemical system according to a third embodiment of the present application is shown. Compared with the first embodiment and the second embodiment, in the third embodiment, the skeleton rubber sealing device includes a plurality of skeletons 2. The plurality of skeletons 2 are arranged in the sealing portion main body 1 along the vertical direction z, and adjacent skeletons 2 are spaced apart at the same distance or different distances. Correspondingly, the sealing portion main body 1 includes a first protruding portion 12 at a position corresponding to the skeleton 2 on the first sealing surface 10. Optionally, the sealing portion main body 1 includes a second protruding portion 13 at a position corresponding to the skeleton 2 on the second sealing surface 11. In other words, the first protruding portion 12 and the second protruding portion 13 of the sealing portion main body 1 are mirror-symmetrical about a middle plane parallel to and equidistant from the first sealing surface 10 and the second sealing surface 11. Compared with a single skeleton 2, using a plurality of skeletons 2 can further increase the contact pressure between the first sealing surface 10 and the second sealing surface 11 before reaching the failure limit. It should be noted that other arrangements of the plurality of skeletons 2 are also within the scope of the present application.

[0027] Figure 5A partial cross-sectional view of a skeleton rubber sealing device for an electrochemical system according to a fourth embodiment of the present application is shown. Compared with the first and second embodiments, in the fourth embodiment, the skeleton rubber sealing device includes a plurality of skeletons 2. The plurality of skeletons 2 are arranged on a plane parallel to the first sealing surface 10 in the sealing portion main body 1, and adjacent skeletons 2 are spaced apart at the same distance or different distances. Accordingly, the sealing portion main body 1 includes a plurality of first protruding portions 12. Each first protruding portion 12 is arranged at a position corresponding to each skeleton 2 on the first sealing surface 10. Optionally, the sealing portion main body 1 includes a plurality of second protruding portions 13, and each second protruding portion 13 is arranged at a position corresponding to each skeleton 2 on the second sealing surface 11. In other words, each first protruding portion 12 and the corresponding second protruding portion 13 of the sealing portion main body 1 are mirror-symmetrical about a middle plane parallel to and equidistant from the first sealing surface 10 and the second sealing surface 11. Compared with a single skeleton 2, the use of a plurality of skeletons 2 provides redundancy for the skeleton rubber sealing device, that is, the main pressure-bearing parts of the skeleton rubber sealing device are each first protruding portion 12 on the first sealing surface 10, and each second protruding portion 13 on the second sealing surface 11 or thereon.

[0028] Figure 6 A cross-sectional view of a skeleton rubber sealing device for an electrochemical system according to other embodiments of the present application is shown. As Figure 6 shown, the skeleton 2 can have a rectangular, hexagonal, or trapezoidal cross-sectional shape. Accordingly, the sealing portion main body 1 includes a first protruding portion 12 at a position corresponding to the skeleton 2 on the first sealing surface 10. Optionally, the sealing portion main body 1 includes a second protruding portion 13 at a position corresponding to the skeleton 2 on the second sealing surface 11. In other words, the first protruding portion 12 and the second protruding portion 13 of the sealing portion main body 1 are mirror-symmetrical about a middle plane parallel to and equidistant from the first sealing surface 10 and the second sealing surface 11. It should be noted that other cross-sectional shapes of the skeleton 2 are also within the scope of the present application.

[0029] The foregoing description of the embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the embodiments to the variants described. Many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described to best illustrate the principles and practical applications, so that those skilled in the art can understand the embodiments from their various embodiments and the various modifications applicable to their intended uses. Within the framework of the embodiments, the above components and features can be combined between different embodiments.

Claims

1. A skeleton rubber sealing device for an electrochemical system, the skeleton rubber sealing device comprising a sealing part main body (1) and a skeleton (2); Characterized in that, The sealing part main body (1) has a first sealing surface (10) and a second sealing surface (11) that are parallel to each other and opposite to each other in a first direction; and The skeleton (2) is strip-shaped and is arranged in the sealing part main body (1) without directly contacting the first sealing surface (10) and the second sealing surface (11).

2. The skeleton rubber sealing device according to claim 1, wherein, The skeleton (2) has a cross-sectional shape that is circular, rectangular, hexagonal, or trapezoidal.

3. The skeleton rubber sealing device according to claim 2, wherein, The skeleton (2) is arranged in the sealing part main body (1) at a distance that is substantially equal from the first sealing surface (10) and the second sealing surface (11).

4. The skeleton rubber sealing device according to claim 3, wherein, The skeleton rubber sealing device is manufactured by a molding process; The sealing part main body (1) is made of silicone rubber or ethylene propylene diene monomer rubber; and The skeleton (2) is made of metal or carbon fiber material, or is made of silicone rubber or ethylene propylene diene monomer rubber with a hardness higher than that of the sealing part main body (1).

5. The skeleton rubber sealing device according to any one of claims 1-4, wherein, The skeleton rubber sealing device includes a plurality of skeletons (2); and The plurality of skeletons (2) are arranged in the sealing part main body (1) along a direction perpendicular to the first sealing surface (10) and pointing to the second sealing surface (11), and are spaced apart from each other.

6. The skeleton rubber sealing device according to claim 5, wherein, The sealing part main body (1) includes a first convex part (12) at a position corresponding to the skeleton (2) on the first sealing surface (10).

7. The skeleton rubber sealing device according to claim 6, wherein, The sealing part main body (1) includes a second convex part (13) at a position corresponding to the skeleton (2) on the second sealing surface (11).

8. The skeleton rubber sealing device according to claim 5, wherein, The distance between adjacent skeletons (2) is equal.

9. The skeleton rubber sealing device according to any one of claims 1-4, wherein, The skeleton rubber sealing device includes a plurality of skeletons (2); and The plurality of skeletons (2) are arranged on a plane parallel to the first sealing surface (10) in the sealing part main body (1), and are spaced apart from each other.

10. The skeleton rubber sealing device according to claim 9, wherein, The sealing part main body (1) includes a plurality of first convex parts (12); and Each first convex part (12) is arranged at a position corresponding to each skeleton (2) on the first sealing surface (10).

11. The skeleton rubber sealing device according to claim 10, wherein, The sealing part main body (1) includes a plurality of second convex parts (13); and Each second convex part (13) is arranged at a position corresponding to each skeleton (2) on the second sealing surface (11).

12. The skeleton rubber sealing device according to claim 9, wherein, The distance between adjacent skeletons (2) is equal.

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