A venturi-type proton exchange membrane electrolysis cell flow channel with fish scale-like texture

Abstract

This invention relates to a Venturi-type proton exchange membrane electrolyzer with a fish-scale texture, comprising: multiple parallel Venturi-type channels formed on bipolar plates, each Venturi-type channel having alternating contraction and expansion sections along the fluid flow direction, the contraction and expansion sections being smoothly connected to form a Venturi tubular structure; both ends of the Venturi-type channels being perpendicularly connected to an inlet manifold and an outlet manifold, respectively; the walls of the Venturi-type channels are provided with regularly arranged fish-scale textures extending along the fluid flow direction, the fish-scale textures being composed of periodically repeating basic texture units. Compared with the prior art, this invention enhances fluid disturbance, effectively prevents gas phase retention; improves mass transfer efficiency, meeting the requirements of high current density operation; optimizes flow field stability, and reduces flow resistance.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane electrolyzer equipment technology, and in particular to a Venturi-type proton exchange membrane electrolyzer flow channel with a fish-scale texture. Background Technology

[0002] Proton exchange membrane electrolyzers (PEMECs) separate hydrogen and oxygen through water electrolysis and the mediation of proton exchange membranes. They offer advantages such as cleanliness, high efficiency, high hydrogen purity, and good stability, making them a hot research topic in the new energy field. The flow channel bipolar plate is a core component of PEMECs. Existing mainstream structures (parallel flow channels, serpentine flow channels, etc.) suffer from uneven gas distribution, large pressure drop, and difficulty in venting dead-zone bubbles. While some flow channels incorporate simple microtextures or employ a single Venturi structure, these issues cannot be fundamentally resolved. During PEMEC operation, especially at high current densities, if the generated gas cannot be vented promptly, it will hinder the flow of reacting water, occupy flow channel space, inhibit electrochemical reactions, and reduce the operating efficiency and stability of the PEMEC, becoming a bottleneck for its efficient development.

[0003] The existing technology structure is as follows: 1. Pure Venturi flow channel It consists of inlet / outlet manifolds and several parallel Venturi grooves. The flow channels are smooth tubular, contracting and then expanding along the flow direction. The two ends of the flow channels are vertically connected to the manifolds, allowing for uniform distribution / collection of the fluid. Disturbance relies solely on cross-sectional changes; the wall surface lacks microstructure, resulting in limited disturbance effects.

[0004] 2. Smooth flow channels with micro-textured walls It consists of a manifold and parallel smooth straight grooves. The inner wall of the grooves has random or simple grooves, fish scale patterns, and other micro-textures. The fluid flows directly through the textured inner wall without the gradual change of the Venturi cross section. The texture parameters and arrangement are unclear, and the disturbance effect is uncontrollable.

[0005] The existing technology has the following drawbacks: Disadvantage 1: Insufficient disturbance, prone to gas phase retention under high current density. Problem: Under high current density, gas-liquid two-phase flow is prone to laminar flow, with bubbles adhering and accumulating, causing gas phase stagnation and affecting hydrogen production efficiency.

[0006] Reason: Existing technologies rely on only a single method, either gradual changes in the flow channel cross-section or simple wall microstructures. The former lacks wall-assisted disturbance, and the latter lacks a sudden increase in cross-sectional velocity. Neither can effectively break the boundary layer, resulting in limited efficiency in bubble removal and fluid disturbance.

[0007] Disadvantage 2: Limited mass transfer efficiency, unable to meet high current density requirements. Problem: The electrode surface is not updated in time, and the supply of liquid water is delayed, which affects the continuous progress of the electrolysis reaction.

[0008] Reason: A single structure cannot effectively enhance turbulence and mixing. It cannot quickly remove bubbles, nor can it ensure sufficient contact between the fluid and the electrode, thus limiting the improvement of mass transfer efficiency.

[0009] Disadvantage 3: The flow field is unstable and prone to generating disordered eddies. Problem: Localized flow turbulence increases resistance and disrupts the normal flow field.

[0010] Cause: Existing technologies have abrupt changes at the flow channel contraction-expansion junction or in the wall texture arrangement, without a smooth and continuous geometric transition, making it difficult to avoid local eddies and affecting the stability of the flow field. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of the prior art by providing a Venturi-type proton exchange membrane electrolyzer flow channel with a fish-scale texture, which enhances fluid disturbance, effectively prevents gas phase retention, improves mass transfer efficiency, meets the requirements of high current density operation, optimizes flow field stability, and reduces flow resistance.

[0012] The objective of this invention can be achieved through the following technical solutions: This invention provides a Venturi-type proton exchange membrane electrolyzer flow channel with a fish-scale texture, comprising: Multiple parallel Venturi-type flow channels are formed on the bipolar plate. Each Venturi-type flow channel is alternately provided with a contraction section and an expansion section along the fluid flow direction. The contraction section and the expansion section are smoothly connected to form a Venturi tubular structure. The two ends of the Venturi-type flow channel are perpendicularly connected to the inlet manifold and the outlet manifold, respectively. The venturi-type flow channel has a regularly arranged fish-scale texture extending along the direction of fluid flow. The fish-scale texture is composed of periodically repeating basic texture units.

[0013] Furthermore, the length ratio of the contraction segment to the expansion segment is 2:3.

[0014] Furthermore, the minimum width of the contraction section is 75% of the inlet width of the expansion section, and the outlet width of the expansion section is 150% of the inlet width of the expansion section.

[0015] Furthermore, the basic texture unit includes a groove formed by splicing together arc units with a radius of 0.5 mm, and a uniform groove with a depth of 0.02 mm is formed at the splicing point of adjacent arc units.

[0016] Furthermore, adjacent arc units extend by 0.01 mm in the vertical direction perpendicular to the wall surface to form a groove with a depth of 0.02 mm, and the grooves are staggered in the upper and lower layers of the wall surface.

[0017] In adjacent basic texture units arranged along the flow direction, the grooves are smoothly connected by an arc of the same radius as the arc unit that forms the groove.

[0018] Furthermore, the arc units are arranged in a periodically staggered array, covering the entire flow channel wall, and the groove cross-section is semi-circular.

[0019] Furthermore, the basic texture units have a unit spacing of 0.50 mm perpendicular to the flow direction and a unit spacing of 0.50 mm parallel to the flow direction.

[0020] Furthermore, the bipolar plate has a liquid inlet and a reactant outlet at its two ends, respectively.

[0021] Furthermore, the flow channel is disposed on the bipolar plate and is positioned opposite to the gas diffusion layer.

[0022] Furthermore, one side of the gas diffusion layer is connected to the flow channel, and the other side is connected to the three-in-one membrane electrode.

[0023] When the electrolyzer is running, liquid water enters through the liquid inlet and reacts in the catalytic layer on the anode side to generate oxygen bubbles. These bubbles form on the electrode surface and enter the flow channel. After passing through the gas diffusion layer, they rise along the flow channel and contact the wall. Driven by the shear force generated by the changes in the mainstream flow velocity due to the Venturi structure, and accelerated detachment from the bottom surface due to the continuous disruption of the boundary layer by the wall grooves, the periodic disturbances formed by the groove array further rapidly entrain the detached bubbles into the high-speed mainstream region. Efficient transport is achieved by the sudden increase in flow velocity in the throat and downstream regions, and the bubbles are finally smoothly discharged through the outlet manifold. At the same time, the smooth arc transition between the contraction and expansion sections of the Venturi structure, combined with the regular arrangement of the groove texture, effectively avoids the generation of local eddies in the throat and outlet regions due to drastic changes in flow velocity. This creates a stable flow environment throughout the flow channel, providing favorable conditions for the continuous generation and detachment of bubbles from the bottom surface.

[0024] Compared with the prior art, the present invention has the following advantages: (1) Enhanced fluid disturbance and effective prevention of gas phase retention. This scheme combines macroscopic velocity control of the Venturi channel with microscopic wall disturbance of the fish-scale microtexture, achieving synergistic effect of structure and texture. Venturi structure: The fluid velocity increases sharply in the constriction section (throat) of the channel, generating strong shear force and driving the bubbles to detach. Fish-scale texture: Its regularly arranged grooves (radius 0.5 mm, depth 0.02 mm) continuously disrupt the fluid boundary layer near the wall, preventing bubble adhesion. The combination of the two can effectively break the boundary layer of the gas-liquid two-phase flow, significantly improve the disturbance intensity, promote the rapid detachment and discharge of bubbles, alleviate the gas phase retention problem under high current density, and help maintain an efficient and stable hydrogen production process.

[0025] (2) Improve mass transfer efficiency to meet the requirements of high current density operation. The enhanced disturbance effect directly strengthens the mass exchange in the flow channel. The velocity change caused by the Venturi structure and the periodic eddies generated by the fish scale texture jointly enhance the turbulence and mixing effect of the fluid in the flow channel. This can accelerate the renewal rate of reactants (water) and products (bubbles) on the electrode surface, ensure that liquid water can be supplied to the reaction site in a timely manner, and at the same time quickly remove the generated bubbles, thereby ensuring that the electrolysis reaction can proceed continuously and efficiently, which is especially beneficial to the performance of PEMEC at high current density.

[0026] (3) Optimize flow field stability and reduce flow resistance. A smooth geometric transition is adopted between the contraction and expansion sections of the Venturi structure. The fish-scale texture (grooves) is arranged in a periodic, staggered, regular array and smoothly connected by arcs of the same radius. This eliminates abrupt changes in the structure, making the flow field change more uniform and controllable, and effectively reducing the local disordered eddies caused by drastic changes in flow velocity. This not only reduces the overall flow resistance, but also creates a more uniform and stable flow environment throughout the flow channel, providing favorable conditions for the continuous generation and detachment of bubbles. Attached Figure Description

[0027] Figure 1 An exploded view of the bipolar plate, gas diffusion layer, and three-in-one membrane electrode. Figure 2 A three-dimensional structural diagram of the flow channel of a Venturi-type proton exchange membrane electrolyzer with a fish-scale texture; Figure 3 for Figure 1 A schematic diagram of the fish-scale-like texture in section A.

[0028] Figure reference numerals: 1-Bipolar plate; 111-Venturi channel; 112-Expansion section; 113-Contraction section; 114-Liquid inlet; 115-Reactant outlet; 116-Inlet manifold; 117-Outlet manifold; 2-Gas diffusion layer; 3-Three-in-one membrane electrode. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0030] Example 1 This embodiment provides a Venturi-type proton exchange membrane electrolyzer flow channel with a fish-scale texture, such as... Figure 1-3 As shown, it includes: Multiple parallel Venturi-type flow channels 111 are formed on the bipolar plate 1. Each Venturi-type flow channel 111 is alternately provided with a contraction section 113 and an expansion section 112 along the fluid flow direction. The contraction section 113 and the expansion section 112 are smoothly connected to form a Venturi tubular structure. The two ends of the Venturi-type flow channel 111 are vertically connected to the inlet manifold 116 and the outlet manifold 117, respectively. The wall surface of the Venturi-type flow channel 111 is provided with a regularly arranged fish-scale texture extending along the fluid flow direction, and the fish-scale texture is composed of periodically repeating basic texture units.

[0031] Example 2 This embodiment provides a Venturi-type proton exchange membrane electrolyzer flow channel with a fish-scale texture, such as... Figure 1-3 As shown, it includes: Multiple parallel Venturi-type flow channels 111 are formed on the bipolar plate 1. Each Venturi-type flow channel 111 is alternately provided with a contraction section 113 and an expansion section 112 along the fluid flow direction. The contraction section 113 and the expansion section 112 are smoothly connected to form a Venturi tubular structure. The two ends of the Venturi-type flow channel 111 are vertically connected to the inlet manifold 116 and the outlet manifold 117, respectively. The wall surface of the Venturi-type flow channel 111 is provided with a regularly arranged fish-scale texture extending along the fluid flow direction, and the fish-scale texture is composed of periodically repeating basic texture units.

[0032] In a specific embodiment, the length ratio of the contraction section 113 to the expansion section 112 is 2:3.

[0033] In a specific embodiment, the minimum width of the contraction section 113 is 75% of the inlet width of the expansion section 112, and the outlet width of the expansion section 112 is 150% of the inlet width of the expansion section 112.

[0034] In a specific embodiment, the basic texture unit includes a groove formed by splicing together arc units with a radius of 0.5 mm, and a uniform groove with a depth of 0.02 mm is formed at the splicing point of adjacent arc units.

[0035] In a specific embodiment, adjacent arc units extend by 0.01 mm in the vertical direction perpendicular to the wall surface to form a groove with a depth of 0.02 mm, and the grooves are staggered in the upper and lower layers of the wall surface.

[0036] In adjacent basic texture units arranged along the flow direction, the grooves are smoothly connected by an arc of the same radius as the arc unit that forms the groove.

[0037] In a specific embodiment, the arc units are arranged in a periodic staggered array, covering the entire flow channel wall, and the groove cross-section is semi-circular.

[0038] In a specific implementation, the basic texture units have a unit spacing of 0.50 mm perpendicular to the flow direction and a unit spacing of 0.50 mm parallel to the flow direction.

[0039] In a specific embodiment, the bipolar plate 1 has a liquid inlet 114 and a reactant outlet 115 at its two ends.

[0040] In a specific embodiment, the flow channel is disposed on the bipolar plate 1 and is disposed opposite to the gas diffusion layer 2.

[0041] In a specific embodiment, one side of the gas diffusion layer 2 is connected to the flow channel, and the other side is connected to the three-in-one membrane electrode 3.

[0042] When the electrolytic cell is running, liquid water enters through the liquid inlet 114 and reacts in the catalytic layer on the anode side to generate oxygen bubbles. These bubbles form on the electrode surface and enter the flow channel. After passing through the gas diffusion layer 2, they rise along the flow channel and come into contact with the wall. Driven by the shear force generated by the change in mainstream flow velocity due to the Venturi structure, and accelerated detachment from the bottom surface due to the continuous disruption of the boundary layer by the wall grooves, the periodic disturbances formed by the groove array further rapidly entrain the detached bubbles into the mainstream high-speed zone. Efficient transport is achieved by the sudden increase in flow velocity in the throat and downstream regions, and finally, the bubbles are smoothly discharged through the outlet manifold. At the same time, the smooth arc transition between the contraction and expansion sections of the Venturi structure, combined with the regular arrangement of the groove texture, effectively avoids the generation of local eddies in the throat and outlet regions due to drastic changes in flow velocity. This creates a stable flow environment throughout the flow channel, providing favorable conditions for the continuous generation and detachment of bubbles from the bottom surface.

[0043] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0044] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A Venturi-type proton exchange membrane electrolyser flow channel with fish scale-like texture, characterised in that, include: Multiple parallel Venturi-type flow channels (111) are formed on the bipolar plate (1). Each Venturi-type flow channel (111) is alternately provided with a contraction section (113) and an expansion section (112) along the fluid flow direction. The contraction section (113) and the expansion section (112) are connected to form a Venturi tubular structure. The two ends of the Venturi-type flow channel (111) are perpendicularly connected to the inlet manifold (116) and the outlet manifold (117), respectively. The venturi-type flow channel (111) has a regularly arranged fish-scale texture extending along the fluid flow direction on its wall surface. The fish-scale texture is composed of periodically repeating basic texture units.

2. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The length ratio of the contraction segment (113) to the expansion segment (112) is 2:

3.

3. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The minimum width of the contraction section (113) is 75% of the inlet width of the expansion section (112), and the outlet width of the expansion section (112) is 150% of the inlet width of the expansion section (112).

4. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The basic texture unit includes a groove formed by splicing together arc units with a radius of 0.5 mm, and a uniform groove with a depth of 0.02 mm is formed at the splicing point of adjacent arc units.

5. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 4, characterized in that, Adjacent arc units extend 0.01 mm vertically in the direction perpendicular to the wall surface to form a groove with a depth of 0.02 mm. The grooves are staggered in the upper and lower layers of the wall surface.

6. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 4, characterized in that, The arc units are arranged in a periodic staggered array, covering the entire flow channel wall, and the groove cross-section is semi-circular.

7. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The basic texture units have a unit spacing of 0.50 mm perpendicular to the flow direction and a unit spacing of 0.50 mm parallel to the flow direction.

8. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The bipolar plate (1) has a liquid inlet (114) and a reactant outlet (115) at its two ends.

9. The Venturi-type proton exchange membrane electrolyzer flow channel with fish-scale texture according to claim 1, characterized in that, The flow channel is set on the bipolar plate (1) and is positioned opposite to the gas diffusion layer (2).

10. The flow channel of a Venturi-type proton exchange membrane electrolyzer with a fish-scale texture according to claim 9, characterized in that, The gas diffusion layer (2) is connected to the flow channel on one side and to the three-in-one membrane electrode (3) on the other side.

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