PEM electrolytic bath pole plate sealing structure and PEM water electrolysis hydrogen production device

Abstract

The utility model relates to a sealing structure of a PEM electrolytic bath pole plate and a PEM water electrolysis hydrogen production device, and belongs to the technical field of water electrolysis hydrogen production. The utility model provides a sealing structure of a PEM electrolytic bath pole plate. The sealing structure comprises a pole plate and a sealing ring, one side of the polar plate is sunken inwards to form a sealing groove; the sealing ring is embedded in the sealing groove; the section of the sealing ring is heart-shaped; the section of the sealing groove is in a semi-dovetail shape. According to the sealing structure, the heart-shaped sealing ring and the semi-dovetail-shaped polar plate sealing groove are adopted, so that when assembling force is applied, the sealing ring is free of rolling and twisting phenomena and stable in position in the process of filling the sealing groove with the sealing ring, and therefore the sealing structure can effectively solve the problems that the sealing ring is exposed or product gas leaks and the like, has the advantage of being better in sealing performance, and is suitable for large-scale popularization and application. And the method is suitable for a larger-scale PEM electrolytic bath.

Description

Technical Field

[0001] The utility model relates to a sealing structure of a PEM electrolyzer plate and a PEM water electrolysis hydrogen production device, belonging to the technical field of water electrolysis hydrogen production. Background Art

[0002] The process of water electrolysis for hydrogen production mainly involves passing direct current into an electrolytic cell filled with electrolyte. Water molecules undergo electrochemical reactions on the electrodes, decomposing into hydrogen and oxygen, which are precipitated at the cathode and anode, respectively. Currently, there are three main types of water electrolysis hydrogen production systems, including alkaline water electrolysis hydrogen production systems, proton exchange membrane (PEM) water electrolysis water electrolysis hydrogen production systems, and solid oxide water electrolysis water electrolysis hydrogen production systems. Among them, the PEM water electrolysis water electrolysis hydrogen production system is more efficient than the alkaline water electrolysis water electrolysis hydrogen production system, produces purer hydrogen, and is more technologically mature than the solid oxide water electrolysis water electrolysis hydrogen production system. Therefore, the PEM water electrolysis water electrolysis hydrogen production system is currently the focus of research and development in the field of water electrolysis hydrogen production technology.

[0003] In proton exchange membrane water electrolysis hydrogen production systems, the sealing structure of the PEM electrolyzer is crucial to its operational safety and electrochemical performance, and is a core technology. Currently, PEM electrolyzers are primarily sealed by extruding a sealing ring between the electrode plates and the membrane electrode, creating a contact seal. With this sealing method, when the PEM electrolyzer produces medium- and high-pressure hydrogen and oxygen products, the sealing ring in the electrode plate sealing groove tends to move outward under the influence of these products. To address this issue, the electrode plate groove and sealing ring structure are generally designed to increase friction on the pressure-bearing contact surface of the sealing ring to prevent leakage of medium- and high-pressure gases.

[0004] However, due to the limited sealing performance of the existing PEM electrolyzer plate sealing structure (the existing PEM electrolyzer plate sealing structure is usually composed of a sealing ring with a rectangular cross-section, a plate with a rectangular cross-section sealing groove, and a sealed chamber composed of a membrane electrode), when the plate flow channel area exceeds 1000 cm 2 Furthermore, when the pressure of hydrogen and oxygen products in the electrolyzer exceeds 3 MPa, the sealing ring is easily exposed, resulting in product gas leakage, which directly affects the safe and stable operation of the PEM electrolyzer. There is an urgent need to design a PEM electrolyzer plate sealing structure with better sealing performance to accommodate larger-scale PEM electrolyzers. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a sealing structure for a PEM electrolyzer plate, the sealing structure comprising a plate and a sealing ring; one side of the plate is recessed inward to form a sealing groove; the sealing ring is embedded in the sealing groove; the cross-section of the sealing ring is a "heart" shape; the cross-section of the sealing groove is a "semi-dovetail" shape.

[0006] In one embodiment of the present invention, the sealing structure is a sealed chamber composed of an electrode plate, a sealing ring and a membrane electrode.

[0007] In one embodiment of the present invention, the sealing ring includes a recessed portion and a pointed end portion; the recessed portion of the sealing ring abuts against the bottom of the sealing groove.

[0008] In one embodiment of the present invention, the sealing structure further includes sealant; the recessed portion of the sealing ring is fixed to the bottom of the sealing groove by the sealant.

[0009] In one embodiment of the present invention, the sum of the volumes of the sealing ring and the sealant is the same as the volume of the sealing groove.

[0010] In one embodiment of the present invention, the cross-sectional depth (H1) of the electrode plate is 0.5 to 15 mm; the cross-sectional depth (H2) of the sealing groove is 0.1 to 15 mm; the cross-sectional width (m1) at the bottom of the sealing groove is 0.5 to 50 mm; and the cross-sectional width (m2) at the top of the sealing groove is 0.2 to 45 mm.

[0011] In one embodiment of the present invention, the "semi-dovetail" cross-section of the sealing groove is composed of four sides, namely a bottom side, a top side, a right-angle side and a hypotenuse; the sealing groove is provided with a first chamfer at the junction of the bottom side and the hypotenuse; the axial diameter (R1) of the first chamfer is 0 to 50 mm; the sealing groove is provided with a second chamfer at the junction of the bottom side and the right-angle side; the axial diameter (R2) of the second chamfer is 0 to 50 mm; the angle (a1) between the hypotenuse and the right-angle side is 0.5 to 45°.

[0012] In one embodiment of the present invention, the "heart"-shaped cross-section of the sealing ring is completely symmetrical on the left and right, and the "heart"-shaped cross-section of the sealing ring is composed of an inward-concave arc segment, two first C-shaped arc segments, two second C-shaped arc segments and an outward-convex arc segment; the first C-shaped arc segment and the second C-shaped arc segment are connected, and the first C-shaped arc segment and the second C-shaped arc segment are located between the inward-concave arc segment and the outward-convex arc segment; the inward-concave arc segment is located at the tip of the sealing ring; the outward-convex arc segment is located at the recessed part of the sealing ring; the axial diameter (R3) of the inward-concave arc segment is 0.1~30mm; the axial diameter (R4) of the first C-shaped arc segment is 1~50mm; the axial diameter (R5) of the second C-shaped arc segment is 1~100mm; the axial diameter (R6) of the outward-convex arc segment is 0.1~50mm.

[0013] In one embodiment of the present invention, the electrode plate is a cathode plate and / or an anode plate of a PEM electrolyzer.

[0014] In one embodiment of the present invention, the material of the sealing ring includes at least one of silicone rubber, fluororubber, EPDM rubber, polytetrafluoroethylene, chloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, double fluororubber or metal rubber.

[0015] The utility model also provides a PEM electrolyzer, which is provided with the above-mentioned sealing structure.

[0016] In one embodiment of the present invention, the sealing structure is provided on the cathode plate or the anode plate of the PEM electrolyzer alone, or the sealing structure is provided on both the cathode plate and the anode plate of the PEM electrolyzer.

[0017] In one embodiment of the present invention, the sealing structures on the cathode plate and the anode plate are symmetrically or asymmetrically arranged.

[0018] The utility model also provides a PEM water electrolysis hydrogen production device, which includes the above-mentioned PEM electrolysis cell.

[0019] The technical solution of this utility model has the following advantages:

[0020] The utility model provides a sealing structure for a PEM electrolyzer plate, comprising a plate and a sealing ring. One side of the plate is recessed inward to form a sealing groove. The sealing ring is embedded in the sealing groove. The sealing ring has a heart-shaped cross-section, while the sealing groove has a semi-dovetail cross-section. When using this sealing structure to seal a single cell in a PEM electrolyzer, sealant is first applied to the bottom of the plate sealing groove. The heart-shaped sealing ring is then placed in the plate sealing groove. Finally, an assembly force is applied during assembly of the PEM electrolyzer to effectively seal the single cell and achieve a matching design process for the PEM electrolyzer. This sealing structure utilizes a heart-shaped sealing ring and a semi-dovetail plate sealing groove. When the assembly force is applied, the sealing ring does not roll or twist during filling into the sealing groove, maintaining a stable position. Therefore, this sealing structure effectively addresses issues such as exposed sealing rings or product gas leakage, offering improved sealing performance and suitability for larger-scale PEM electrolyzers.

[0021] Furthermore, the sealing ring includes a recessed portion and a pointed portion; the recessed portion of the sealing ring abuts the bottom of the sealing groove. This sealing structure changes the design of the electrode plate sealing groove and the sealing ring, designing the sealing ring into a "heart" shape and the electrode plate sealing groove into a "semi-dovetail" shape. The recessed portion of the sealing ring (i.e., the upper area of ​​the "heart"-shaped sealing ring) is placed at the bottom of the electrode plate sealing groove (i.e., the top of the electrode plate sealing groove). This prevents the PEM electrolyzer from being impacted by external gas forces, making it difficult for the sealing ring to squeeze out of the sealing groove when the recessed portion of the sealing ring and the "semi-dovetail" sealing groove of the electrode plate are squeezed by external forces. This effectively prevents the sealing ring from squeezing out of the gap and "biting" phenomena, further solving problems such as exposed sealing rings or product gas leakage in PEM electrolyzers, and has great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : Schematic diagram of the location of the PEM electrolyzer plate sealing structure. Figure 1 In the figure, area A is the flow field structure area of ​​the bipolar plate.

[0023] Figure 2 : Figure 1 Cross-sectional view of section 1-1.

[0024] Figure 3 : Schematic diagram of the structure of the sealing ring.

[0025] Figure 4 : The process of forming the sealing structure between the PEM electrolyzer plate and the membrane electrode (before compression).

[0026] Figure 5 : The process of forming the sealing structure between the PEM electrolyzer plate and the membrane electrode (after compression).

[0027] Figures 1 to 5 Among them, the electrode plate 1, the sealing ring 2, the sealing groove 3, the recessed part 4, the tip 5, the groove bottom 6, and the sealant 7. DETAILED DESCRIPTION

[0028] The following embodiments are provided to further understand the present invention, but are not intended to limit the present invention to the best implementation mode described herein and do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention that is derived by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0029] If no specific experimental steps or conditions are specified in the following examples, the experiments were carried out according to the conventional experimental steps or conditions described in the literature in the field. If no manufacturer is specified for the reagents or instruments used, they are all commercially available conventional reagents.

[0030] Example 1: A sealing structure for a PEM electrolyzer plate

[0031] like Figures 1 to 5 As shown, this embodiment provides a sealing structure for a PEM electrolyzer plate, wherein the sealing structure comprises a sealed chamber consisting of a plate 1, a sealing ring 2, and a membrane electrode; one side of the plate 1 is recessed inward to form a sealing groove 3; the sealing ring 2 is embedded in the sealing groove 3; the cross section of the sealing ring 2 is a "heart" shape; the cross section of the sealing groove 3 is a "semi-dovetail" shape; the sealing ring 2 comprises a recessed portion 4 and a tip portion 5; the recessed portion 4 of the sealing ring 2 abuts against the bottom 6 of the sealing groove 3; the sealing structure further comprises a sealant 7; the sealing The recessed portion 4 of the ring 2 is fixed to the bottom 6 of the sealing groove 3 by the sealant 7; the sum of the volumes of the sealing ring 2 and the sealant 7 is the same as the volume of the sealing groove 3; the cross-sectional depth (H1) of the electrode plate is 4 mm; the cross-sectional depth (H2) of the sealing groove is 3 mm; the cross-sectional width (m1) at the bottom of the sealing groove is 5 mm; the cross-sectional width (m2) at the top of the sealing groove is 4 mm; the "half-dovetail" cross-section of the sealing groove is composed of four sides: the bottom side, the top side, the right-angle side and the oblique side; the sealing groove A first chamfer is provided at the junction of the bottom edge and the hypotenuse; the axial diameter (R1) of the first chamfer is 5 mm; a second chamfer is provided at the junction of the bottom edge and the right-angled side of the sealing groove; the axial diameter (R2) of the second chamfer is 5 mm; the angle (a1) between the hypotenuse and the right-angled side is 15°; the "heart"-shaped cross section of the sealing ring is completely symmetrical on the left and right, and the "heart"-shaped cross section of the sealing ring is composed of an inwardly concave arc segment, two first C-shaped arc segments, two second C-shaped arc segments and an outwardly convex arc segment; the first C-shaped arc segment and The second C-shaped arc segment is connected, and the first C-shaped arc segment and the second C-shaped arc segment are located between the concave arc segment and the convex arc segment; the concave arc segment is located at the tip of the sealing ring; the convex arc segment is located at the recessed part of the sealing ring; the axial diameter (R3) of the concave arc segment is 10 mm; the axial diameter (R4) of the first C-shaped arc segment is 25 mm; the axial diameter (R5) of the second C-shaped arc segment is 60 mm; the axial diameter (R6) of the convex arc segment is 30 mm; the material of the sealing ring 2 is silicone rubber.

[0032] When using this sealing structure to seal a single chamber of a PEM electrolyzer, first apply sealant to the bottom of the electrode plate sealing groove, then place a "heart"-shaped sealing ring in the electrode plate sealing groove, and finally apply assembly force during the assembly process of the PEM electrolyzer to achieve effective sealing of the single chamber of the PEM electrolyzer and simultaneously realize the matching design process of the PEM electrolyzer.

[0033] The sealing structure changes the design of the electrode plate sealing groove and the sealing ring, designs the sealing ring into a "heart" shape, designs the electrode plate sealing groove into a "half-dovetail" shape, and places the recessed portion of the sealing ring (i.e., the upper area of ​​the "heart"-shaped sealing ring) at the bottom of the electrode plate sealing groove (i.e., the top of the electrode plate sealing groove). When the assembly force is applied, the sealing ring does not roll or twist during the process of filling the sealing groove, and its position is stable. In addition, the interior of the PEM electrolyzer is impacted by external gas force, resulting in the recessed portion of the sealing ring and the "half-dovetail" sealing groove of the electrode plate being not easily squeezed out of the sealing groove when subjected to external force compression, effectively preventing the sealing ring from squeezing out of the gap and "biting" and other phenomena, and can well solve problems such as exposed sealing ring or gas leakage.

[0034] The sealing structure is set on a 250kW PEM electrolyzer (two sealing structures are set, and the two sealing structures are set on the cathode plate and the anode plate at the same time, and the cathode plate and the anode plate are set symmetrically). Figure 5 ) Nitrogen was introduced into both the oxygen and hydrogen outlets of the PEM electrolyzer for a leak test (see GB / T37562-2019 for leak testing). The pressure was first increased to 1.01 MPa, stabilized for 15 minutes, then raised to 1.52 MPa, stabilized for 15 minutes, and then raised to 3.04 MPa, maintained for 30 hours. The pressure dropped to 2.97 MPa, with a leakage rate of 0.08%, indicating the leak test passed.

[0035] Comparative Example 1: A sealing structure for a PEM electrolyzer plate

[0036] This comparative example provides a sealing structure for a PEM electrolyzer electrode plate. The sealing structure is based on Example 1 and uses a sealing ring with a rectangular cross-section and a sealing groove with a rectangular cross-section, wherein the cross-sectional depth (H1) of the electrode plate is 4 mm, the cross-sectional depth (H2) of the sealing groove is 3 mm, the axial diameter (R1) of the first chamfer is 5 mm, the axial diameter (R2) of the second chamfer is 5 mm, the cross-sectional width (m1=m2) at the bottom and top of the sealing groove is both 5 mm, the cross-sectional depth of the sealing ring is 4 mm, and the cross-sectional width of the sealing ring is 5 mm.

[0037] The sealing structure is set on a 250kW PEM electrolyzer (two sealing structures are set, and the two sealing structures are set on the cathode plate and the anode plate at the same time, and the cathode plate and the anode plate are set symmetrically). After the bipolar plates are sealed and pressed, nitrogen is introduced into the oxygen side outlet and the hydrogen side outlet of the PEM electrolyzer at the same time, and an air tightness test is performed on it (for air tightness test, see GB / T37562-2019). The pressure is first increased to 1.02MPa, stabilized for 15min, then increased to 1.51MPa, stabilized for 10min, and then increased to 2.03MPa. The sealing ring of the fifth chamber leaks and the air tightness test fails.

[0038] Example 2: A PEM electrolyzer

[0039] This embodiment provides a PEM electrolyzer, which is provided with the sealing structure of embodiment 1; the sealing structure is provided on both the cathode plate and the anode plate of the PEM electrolyzer; the sealing structures on the cathode plate and the anode plate are symmetrically arranged.

[0040] Example 3: A PEM water electrolysis hydrogen production device

[0041] This embodiment provides a PEM water electrolysis hydrogen production device, which includes the PEM electrolyzer of Example 2.

[0042] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A sealing structure for a PEM electrolyzer plate, characterized in that: The sealing structure includes a plate and a sealing ring; one side of the plate is recessed inward to form a sealing groove; the sealing ring is embedded in the sealing groove; the cross-section of the sealing ring is a "heart" shape; the cross-section of the sealing groove is a "semi-dovetail" shape.

2. The sealing structure according to claim 1, wherein: The sealing structure is a sealed chamber composed of an electrode plate, a sealing ring and a membrane electrode.

3. The sealing structure according to claim 1, wherein: The sealing ring comprises a recessed portion and a tip portion; the recessed portion of the sealing ring abuts against the bottom of the sealing groove.

4. The sealing structure according to any one of claims 1 to 3, wherein: The sealing structure further comprises a sealant; the recessed portion of the sealing ring is fixed to the bottom of the sealing groove by the sealant.

5. The sealing structure according to claim 4, wherein: The sum of the volumes of the sealing ring and the sealant is the same as the volume of the sealing groove.

6. The sealing structure according to claim 1, wherein: The cross-sectional depth of the electrode plate is 0.5 to 15 mm; the cross-sectional depth of the sealing groove is 0.1 to 15 mm; the cross-sectional width at the bottom of the sealing groove is 0.5 to 50 mm; and the cross-sectional width at the top of the sealing groove is 0.2 to 45 mm.

7. The sealing structure according to claim 1, wherein: The "semi-dovetail" cross-section of the sealing groove consists of four sides: a bottom side, a top side, a right-angle side, and a hypotenuse. The sealing groove is provided with a first chamfer at the junction of the bottom side and the hypotenuse. The axial diameter of the first chamfer is 0 to 50 mm. The sealing groove is provided with a second chamfer at the junction of the bottom side and the right-angle side. The axial diameter of the second chamfer is 0 to 50 mm. The angle between the hypotenuse and the right-angle side is 0.5 to 45 degrees.

8. The sealing structure according to claim 1, wherein: The "heart"-shaped cross-section of the sealing ring is completely symmetrical on the left and right, and the "heart"-shaped cross-section of the sealing ring is composed of an inward-concave arc segment, two first C-shaped arc segments, two second C-shaped arc segments and an outward-convex arc segment; the first C-shaped arc segment and the second C-shaped arc segment are connected, and the first C-shaped arc segment and the second C-shaped arc segment are located between the inward-concave arc segment and the outward-convex arc segment; the axial diameter of the inward-concave arc segment is 0.1 to 30 mm; the axial diameter of the first C-shaped arc segment is 1 to 50 mm; the axial diameter of the second C-shaped arc segment is 1 to 100 mm; the axial diameter of the outward-convex arc segment is 0.1 to 50 mm.

9. A PEM electrolyzer, characterized in that: The PEM electrolyzer is provided with the sealing structure according to any one of claims 1 to 8.

10. A PEM water electrolysis hydrogen production device, characterized in that: The PEM water electrolysis hydrogen production device includes the PEM electrolyzer according to claim 9.

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