Runner structure for producing hydrogen by electrolyzing water

Abstract

The invention belongs to the technical field of hydrogen production through water electrolysis, and relates to a runner structure for hydrogen production through water electrolysis. A plurality of concave parts (3) are arranged on the plurality of concave combination strips (1) at intervals, a plurality of convex parts (4) are arranged on the plurality of convex combination strips (2), the side surface of each concave combination strip (1) is connected with the side surface of the adjacent convex combination strip (2), and the side surface of each convex combination strip (2) is connected with the side surface of the adjacent concave combination strip (1). Each downward concave part (3) on the downward concave combination strips (1) is aligned with the corresponding upward convex part (4) on the upward convex combination strips (2) in the horizontal direction, and the corresponding downward concave parts (3) of the plurality of downward concave combination strips (1) and the corresponding upward concave parts (4) of the plurality of upward convex combination strips (2) form a plurality of runner straight through holes (5). The flow channel structure for hydrogen production through water electrolysis is low in cost, simple in machining mode and capable of effectively providing a mass transfer channel, reducing contact resistance between parts and improving the overall performance of an electrolytic cell.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen production by water electrolysis, and more specifically relates to a flow channel structure for hydrogen production by water electrolysis. BACKGROUND

[0002] With the increasing demand for clean energy worldwide, PEM (Proton Exchange Membrane) hydrogen production technology has become a research hotspot and development trend in the current hydrogen production field due to its advantages of high efficiency, environmental protection, and good matching with renewable energy. PEM electrolysis tank produces hydrogen by electrolyzing water. In the entire process, the design of the flow field plays a key role in the performance of the electrolysis tank. The flow field needs to ensure that the reaction medium can be uniformly and efficiently transmitted to the reaction surface, while timely removing the reaction products (hydrogen and oxygen) to maintain the stable and efficient operation of the electrolysis tank. A good flow field design not only improves the electrolysis efficiency, but also prolongs the service life of the electrolysis tank and reduces the operating cost, which is of great significance for promoting the large-scale commercial application of PEM hydrogen production technology.

[0003] In the existing design of PEM hydrogen production electrolyzer, the anode flow field design is crucial. The oxygen generated at the anode will directly affect the water transfer to the membrane electrode if it accumulates to form a "gas plug", forming a "mass transfer resistance". The current common flow channel forms include traditional etching flow channel, titanium mesh flow channel and mechanical processing flow channel. The traditional etching flow channel usually forms a groove of a specific shape and size on the metal plate through etching process to guide the flow of water and gas. However, this etching flow channel has many problems: on the one hand, the etching process has high cost, which requires special equipment and complex process flow, increasing the manufacturing cost of the electrolyzer; on the other hand, due to the particularity of the processing technology, the etching flow channel has limitations on the depth-width ratio. If the depth-width ratio is too large, the etching liquid will update slowly at the bottom of the flow channel, which may cause uneven etching of the side wall (inverted cone or wedge shape), affecting the size and accuracy of the flow channel, and also bringing certain limitations to the flow channel design. The scheme of using titanium mesh as the flow channel simplifies the manufacturing process to some extent, but the core problem is that it has no obvious flow channel structure. This structural defect is particularly prominent when running at high current density: a large number of generated bubbles will occupy the limited mesh space, making it difficult for pure water required for the reaction to be transported to the reaction surface, resulting in local water shortage of the membrane electrode, and the heat generated by the reaction is also difficult to dissipate effectively, causing local overheating and seriously shortening the service life of the membrane electrode. In addition, under high current density, the electrolyzer needs a large amount of pure water to participate in the reaction, and also relies on water flow to carry away the heat generated by the reaction. However, due to the lack of obvious flow channel, the water flow has a large flow resistance when passing through, which cannot efficiently transport sufficient pure water, which will further exacerbate the influence of mass transfer resistance, increase the energy consumption of the electrolyzer, and restrict the improvement of the overall performance of the electrolyzer. There are also technical solutions that use stamped bipolar plates. The stamping process can process a large number of plates at low cost in a short time. However, the influence of the stamping process in the specific implementation process will cause the cross-section of the flow channel to be not a complete trapezoid, but a semicircular arc, so the contact between the plate and the diffusion layer is actually the contact between the arc and the point. The small contact area leads to a large ohmic resistance. Moreover, the electrolyzer scale in the industry is small, the mold cost and equipment cost of the early investment are large, and the return period is long. At the same time, the stamped bipolar plate is a relatively new structure in the field of PEM electrolytic water hydrogen production, and it is urgent to verify its related performance and feasibility through relevant durability tests.

[0004] Existing technology includes a bipolar plate and electrolyzer for alkaline water electrolysis to produce hydrogen, published under publication number CN218969380U. This technology provides a bipolar plate and electrolyzer for alkaline water electrolysis to produce hydrogen. The bipolar plate is formed with a continuous wavy cross-section, resulting in multiple strip-shaped flow channels on both the front and back sides of the bipolar plate, with the strip-shaped flow channels on the front and back sides alternating. This invention's bipolar plate increases the contact area between the bipolar plate and the electrodes, reduces contact resistance, and improves the efficiency of the electrolyzer. The design of the strip-shaped flow channels optimizes the flow field of the alkaline solution and gas within the electrolyzer, reducing fluid stagnation and backflow problems, and preventing local gas accumulation and membrane penetration. It also optimizes the temperature field within the electrolyzer, avoiding localized high temperatures. Furthermore, the bipolar plate reduces the assembly difficulty and production cost of the electrolyzer.

[0005] However, this technology does not address the technical issues and solutions of this application. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a flow channel structure for hydrogen production by water electrolysis, which is simple in structure, low in cost, easy to process, can effectively provide mass transfer channels, reduce contact resistance between components, and improve the overall performance of the electrolyzer, in order to overcome the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to a flow channel structure for hydrogen production via water electrolysis, comprising multiple concave composite strips and multiple convex composite strips. Multiple concave portions are spaced apart on the multiple concave composite strips, and multiple convex portions are spaced apart on the multiple convex composite strips. The side of each concave composite strip is connected to the side of an adjacent convex composite strip, and the side of each convex composite strip is connected to the side of an adjacent concave composite strip. Each concave portion on the concave composite strip is horizontally aligned with a corresponding convex portion on the convex composite strip. The corresponding concave portions of the multiple concave composite strips and the corresponding convex portions of the multiple convex composite strips form multiple flow channel through holes.

[0008] The side of each concave composite strip is fixedly welded to the side of the adjacent convex composite strip, and the side of each convex composite strip is fixedly welded to the side of the adjacent concave composite strip.

[0009] Both the multiple concave and convex composite strips are made of titanium plate.

[0010] The thickness of the multi-recessed and multi-convex composite strips is 0.1~0.3mm.

[0011] Multiple concave and convex strips form a flow channel plate for hydrogen production. The left sides of the multiple concave and convex strips are aligned, and the right sides of the multiple concave and convex strips are aligned.

[0012] The flow channel structure for hydrogen production via water electrolysis also includes a titanium plate and a porous titanium fiber felt, with the flow channel mesh plate for hydrogen production located between the titanium plate and the porous titanium fiber felt.

[0013] The titanium plate is provided with an inlet and an outlet, which are respectively connected to the flow channel through holes of the flow channel mesh plate for hydrogen production.

[0014] The multi-row concave combination strips and the multi-row convex combination strips are structures formed by roller pressing.

[0015] The hydrogen production flow channel mesh plate is embedded in the groove of the titanium plate.

[0016] The bottom surface of the concave part of the multi-recessed composite strip is bonded to a titanium plate, and the top surface of the convex part of the multi-convex composite strip is bonded to a porous titanium fiber felt.

[0017] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The flow channel structure for hydrogen production via water electrolysis described in this invention comprises multiple concave and convex composite strips. The concave composite strips, convex composite strips, and other components of the same flow channel structure have identical shapes and dimensions. The concave and convex composite strips are processed using a roller press, resulting in a simple, efficient, and continuous production process. These strips are then combined to form the flow channel mesh for hydrogen production. When assembling, the directions of the multiple concave and convex composite strips should be opposite. Specifically, connect the side of each concave composite strip to the side of the adjacent convex composite strip, and simultaneously connect the side of each convex composite strip to the side of the adjacent concave composite strip. During the connection setup, each concave portion on the concave composite strip should be horizontally aligned with the corresponding convex portion on the convex composite strip. The corresponding concave portions of the multiple concave composite strips and the corresponding convex portions of the multiple convex composite strips form multiple through-hole flow channels. From the cross-sectional diagram, the through-holes in the flow channel mesh are essentially a type of through-flow channel. Compared to the turbulent structure of traditional titanium mesh, it can better provide mass transfer channels for the electrolyzer and reduce mass transfer resistance. Meanwhile, when the electrolysis reaction occurs on the anode side, oxygen bubbles generated at the three-phase interface are transported to the hydrogen production flow channel mesh plate through the porous titanium fiber felt. At the through-holes of the flow channel mesh, the bubbles are continuously washed away by the pure water along the path, avoiding the phenomenon of oxygen bubbles accumulating and occupying limited mesh openings, thus improving mass transfer capacity. At high current densities, electrolyzers require a large amount of pure water for the electrolysis reaction and thermal management. The perforated flow channel mesh actively facilitates water and gas transport within the electrolyzer, preventing shortened membrane electrode lifespan due to localized overheating. In the hydrogen production flow channel mesh, the mesh is bonded to a titanium plate and then to a porous titanium fiber felt. Pure water, the reactant, flows into the flow channel mesh through the inlet and is then uniformly transferred to the membrane electrode via the bonded porous titanium fiber felt for the electrolytic hydrogen production reaction. Therefore, the tight bonding of the flow channel mesh, titanium plate, and porous titanium fiber felt ensures a smooth supply of pure water to the electrolyzer. Attached Figure Description

[0018] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a schematic diagram of the hydrogen production flow channel mesh plate of the flow channel structure for water electrolysis hydrogen production according to the present invention; Figure 2 This is a partial cross-sectional view of the flow channel mesh plate for hydrogen production using the electrolytic water hydrogen production flow channel structure described in this invention. Figure 3This is a schematic diagram of the hydrogen production flow channel mesh plate of the electrolytic water hydrogen production flow channel structure described in this invention, when arranged on a titanium plate. Figure 4 This is a partial structural schematic diagram of the concave composite strip of the flow channel structure for hydrogen production by water electrolysis according to the present invention; Figure 5 This is a partial structural schematic diagram of the convex composite strip of the flow channel structure for hydrogen production by water electrolysis according to the present invention; The labels in the attached diagram are as follows: 1. Concave composite strip; 2. Convex composite strip; 3. Concave part; 4. Convex part; 5. Straight through hole of flow channel; 6. Flow channel mesh plate for hydrogen production; 7. Titanium plate; 8. Porous titanium fiber felt; 9. Water inlet; 10. Water outlet. Detailed Implementation

[0019] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1 - Appendix Figure 5As shown, this invention discloses a flow channel structure for hydrogen production via water electrolysis, comprising multiple concave composite strips 1 and multiple convex composite strips 2. Multiple concave portions 3 are spaced apart on the multiple concave composite strips 1, and multiple convex portions 4 are provided on the multiple convex composite strips 2. The side of each concave composite strip 1 is connected to the side of an adjacent convex composite strip 2, and the side of each convex composite strip 2 is connected to the side of an adjacent concave composite strip 1. Each concave portion 3 on the concave composite strip 1 is horizontally aligned with a corresponding convex portion 4 on the convex composite strip 2. The corresponding concave portions 3 of the multiple concave composite strips 1 and the corresponding convex portions 4 of the multiple convex composite strips 2 form multiple flow channel through holes 5. This structure addresses the shortcomings of existing technologies by proposing an improved technical solution. In the structural design, multiple concave composite strips 1 and multiple convex composite strips 2 are fabricated separately. The shape and dimensions of the multiple concave composite strips 1 and the multiple convex composite strips 2 are identical for the same flow channel structure used in water electrolysis for hydrogen production. The concave composite strips 1 and convex composite strips 2 are processed using a roller press, a simple and efficient process that allows for continuous production. The multiple concave composite strips 1 and convex composite strips 2 are then combined to form the hydrogen production flow channel mesh plate 6. When assembling, the multiple concave composite strips 1 and the multiple convex composite strips 2 should be in opposite directions. Specifically, the side of each concave composite strip 1 is connected to the side of the adjacent convex composite strip 2, and simultaneously, the side of each convex composite strip 2 is connected to the side of the adjacent concave composite strip 1. During the connection setup, each concave portion 3 on the concave composite strip 1 is horizontally aligned with the corresponding convex portion 4 on the convex composite strip 2. The corresponding concave portions 3 of the multiple concave composite strips 1 and the corresponding convex portions 4 of the multiple convex composite strips 2 form multiple through-holes 5 for flow channels. From the cross-sectional diagram, the through-holes 5 of the flow channel mesh are essentially a type of through-flow channel. Compared with the turbulent structure of traditional titanium mesh, it can better provide mass transfer channels for the electrolytic cell and reduce mass transfer resistance. Meanwhile, when the electrolysis reaction occurs on the anode side, oxygen bubbles generated at the three-phase interface are transported to the hydrogen production flow channel mesh plate through the porous titanium fiber felt. The bubbles at the flow channel mesh openings 5 ​​are continuously washed away by the pure water along this path, preventing the accumulation of oxygen bubbles that would occupy the limited mesh openings and improving mass transfer capacity. At high current densities, the electrolyzer requires a large amount of pure water for the electrolysis reaction and thermal management. The presence of the flow channel mesh openings 5 ​​actively "transports water and gas" to the electrolyzer, preventing shortened membrane electrode life due to localized overheating. When the hydrogen production flow channel mesh plate 6 is used, as... Figure 3As shown, the hydrogen production flow channel plate 6 is bonded and assembled with the titanium plate 7, and simultaneously bonded with the porous titanium fiber felt 8. Pure water, the reactant, flows into the hydrogen production flow channel plate 6 through the inlet 9 for transport, and is then uniformly transferred to the membrane electrode via the bonded porous titanium fiber felt 8 for the electrolytic hydrogen production reaction. Therefore, the tight bonding of the three components—the hydrogen production flow channel plate 6, the titanium plate 7, and the porous titanium fiber felt 8—ensures a smooth supply of pure water to the electrolyzer. The flow channel structure for hydrogen production via water electrolysis described in this invention is low-cost, easy to manufacture, effectively provides a mass transfer channel, reduces contact resistance between components, and improves the overall performance of the electrolyzer.

[0020] Each concave composite strip 1 is fixedly welded to the side of an adjacent convex composite strip 2, and each convex composite strip 2 is fixedly welded to the side of an adjacent concave composite strip 1. In this structure, the multiple concave composite strips 1 and multiple convex composite strips 2 are located on the same plane when connected, and adjacent composite strips are welded to achieve structural fixation. After molding, multiple flow channel mesh holes 5 will be formed.

[0021] Both the multiple concave composite strip 1 and the multiple convex composite strip 2 are made of titanium plate. The thickness of the multiple concave composite strip 1 and the multiple convex composite strip 2 is 0.1~0.3mm. In the above structure, the raw material of the flow channel mesh plate is made of titanium plate (grade: TA1), and the material thickness is selected from 0.1~0.3mm. The thinner titanium plate is easier to process and can be easily and quickly processed into composite strips.

[0022] Multiple concave combined strips 1 and multiple convex combined strips 2 form a hydrogen production flow channel mesh plate 6. The left sides of the multiple concave combined strips 1 and multiple convex combined strips 2 are aligned, and the right sides are aligned. In the above structure, the hydrogen production flow channel mesh plate 6 formed by the multiple concave combined strips 1 and multiple convex combined strips 2 has a square structure. During use, it needs to be embedded in the groove of the titanium plate 7 to achieve a reliable arrangement on the titanium plate.

[0023] The flow channel structure for hydrogen production via water electrolysis also includes a titanium plate 7 and a porous titanium fiber felt 8, with a flow channel mesh plate 6 located between the titanium plate 7 and the porous titanium fiber felt 8. In this structure, the porous titanium fiber felt 8 has a larger area than the flow channel mesh plate 6, and the titanium plate 7 is connected by welding or screws.

[0024] The titanium plate 7 is provided with an inlet 9 and an outlet 10, which are respectively connected to the through holes 5 of the hydrogen production flow channel mesh plate 6. The hydrogen production flow channel mesh plate 6 is embedded in the groove of the titanium plate 7. In the above structure, after the through holes 5 are formed, when the flow channel structure for hydrogen production by water electrolysis is working, when the electrolysis reaction occurs on the anode side, the oxygen bubbles generated at the three-phase interface are transported to the hydrogen production flow channel mesh plate through the porous titanium fiber felt. The bubbles at the through holes 5 are continuously washed away by the pure water along the path, avoiding the phenomenon of oxygen bubbles occupying the limited mesh due to accumulation, thus improving the mass transfer capacity. Under high current density, the electrolyzer requires a large amount of pure water to participate in the electrolysis reaction and thermal management. The presence of the through holes in the flow channel mesh can actively transport water and gas to the electrolyzer, avoiding the shortening of membrane electrode life due to local overheating.

[0025] In the flow channel structure described in this invention, the inlet is located on side 9, and water flows through the novel flow channel structure to the outlet on side 10. Specifically, the inlet and outlet are guided by several flow-guiding structures of the frame (not discussed in this paper), each corresponding to the openings of the inlet and outlet. Since the industry generally uses frame-based flow guidance, this is existing technology. It can be described as: gas / liquid transport is achieved by several flow-guiding structures corresponding to the openings of the inlet and outlet.

[0026] The multiple concave composite strips 1 and multiple convex composite strips 2 are formed by roller pressing. The above structure is simple to process and has low cost.

[0027] The bottom surface of the concave portion 3 of the multi-recessed composite strip 1 is bonded to a titanium plate 7, and the top surface of the convex portion 4 of the multi-convex composite strip 2 is bonded to a porous titanium fiber felt 8. The above structure, as shown... Figure 2 As shown, the hydrogen production flow channel mesh plate 6 is tightly bonded to the porous titanium fiber felt and titanium plate. The upper and lower contact designs of the hydrogen production flow channel mesh plate 6 are both planar. Therefore, compared with the line contact between the traditional titanium mesh and the component, the contact of the hydrogen production flow channel mesh plate 6 is actually a surface contact. The contact area of ​​the component is larger, which can effectively reduce contact resistance, reduce hydrogen production energy consumption, and improve the hydrogen production efficiency of the PEM electrolyzer.

[0028] The flow channel structure for hydrogen production via water electrolysis described in this invention features a straight-through perforated flow channel mesh plate. The concave combined strip 1 and the convex combined strip 2 can be processed using a roller press, tailored to the size of the electrolyzer, and are not limited by the size of the electrolyzer. Production equipment and raw material costs are low, operation is simple, and large-scale mass production is possible. During use, the flow channel mesh plate effectively provides a straight-through mass transfer channel for pure water and oxygen on the anode side, effectively reducing mass transfer resistance. Simultaneously, the surface contact with the components effectively reduces contact resistance and improves electrolysis efficiency.

[0029] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A flow channel structure for hydrogen production by electrolysis of water, characterized by: The application relates to a hydrogen production flow channel structure, which comprises a plurality of lower concave combined strips (1) and a plurality of upper convex combined strips (2), a plurality of lower concave parts (3) are arranged on the plurality of lower concave combined strips (1) at intervals, a plurality of upper convex parts (4) are arranged on the plurality of upper convex combined strips (2), the side surface of each lower concave combined strip (1) is connected with the side surface of an adjacent upper convex combined strip (2), the side surface of each upper convex combined strip (2) is connected with the side surface of an adjacent lower concave combined strip (1), each lower concave part (3) on the lower concave combined strip (1) is horizontally aligned with a corresponding upper convex part (4) on the upper convex combined strip (2), and the corresponding lower concave part (3) of the plurality of lower concave combined strips (1) and the corresponding upper convex part (4) of the plurality of upper convex combined strips (2) form a plurality of flow channel straight-through holes (5).

2. The flow channel structure for hydrogen production by electrolysis of water according to claim 1, characterized by: The side surface of each lower concave combined strip (1) is fixedly welded with the side surface of an adjacent upper convex combined strip (2), and the side surface of each upper convex combined strip (2) is fixedly welded with the side surface of an adjacent lower concave combined strip (1).

3. The flow channel structure for hydrogen production by water electrolysis according to claim 1 or 2, characterized by: The plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) are made of titanium plate materials.

4. The flow channel structure for hydrogen production by water electrolysis according to claim 3, characterized by: The thickness of the plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) is 0.1-0.3 mm.

5. The flow channel structure for hydrogen production by water electrolysis according to claim 1 or 2, characterized by: The plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) form a hydrogen production flow channel net plate (6), the left side edges of the plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) are aligned, and the right side edges of the plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) are aligned.

6. The flow channel structure for hydrogen production by water electrolysis according to claim 1 or 2, characterized by: The hydrogen production flow channel structure further comprises a titanium flat plate (7) and a porous titanium fiber felt (8), and the hydrogen production flow channel net plate (6) is located between the titanium flat plate (7) and the porous titanium fiber felt (8).

7. The flow channel structure for hydrogen production by water electrolysis according to claim 6, characterized by: The titanium flat plate (7) is provided with a water inlet (9) and a water outlet (10), and the water inlet (9) and the water outlet (10) are respectively communicated with the flow channel straight-through holes (5) of the hydrogen production flow channel net plate (6).

8. The flow channel structure for hydrogen production by water electrolysis according to claim 1 or 2, characterized by: The plurality of lower concave combined strips (1) and the plurality of upper convex combined strips (2) are roll group compression molded structures.

9. The flow channel structure for hydrogen production by water electrolysis according to claim 6, characterized by: The hydrogen production flow channel net plate (6) is embedded in a groove of the titanium flat plate (7).

10. The flow channel structure for hydrogen production by water electrolysis according to claim 6, characterized by: The bottom surface of the lower concave part (3) of the plurality of lower concave combined strips (1) is attached to the titanium flat plate (7), and the top surface of the upper convex part (4) of the plurality of upper convex combined strips (2) is attached to the porous titanium fiber felt (8).

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