A flow guide plate water flow channel optimization structure of an AEM electrolytic cell

Abstract

This utility model discloses an optimized structure for the water flow channel of an AEM electrolyzer, relating to the field of AEM electrolysis hydrogen production technology. It includes two sets of guide plates, with a sealing gasket clamped and fixed between them. Each guide plate includes a base plate, and a flow channel is formed on the outer wall of the base plate. The flow channel is S-shaped and distributed on the outer wall of the base plate. At least three sets of guide ribs are fixed at the front, middle, and rear sections of the flow channel corners, and the guide ribs are fixed to the bottom of the flow channel. This utility model, during the reaction process, causes large bubbles to break into multiple smaller bubbles when they contact the tips of the guide ribs at the bends of the flow channel. Furthermore, the multiple sets of guide ribs at the front, middle, and rear ends of the bends prevent small bubbles from coalescing into large bubbles at the bends, thus preventing large bubbles from adsorbing and clogging the flow channel, ensuring efficient bubble discharge. Additionally, the guide ribs are relatively low in height, avoiding excessive obstruction of fluid flow.

Description

Technical Field

[0001] This utility model relates to the field of AEM electrolysis hydrogen production technology, specifically an optimized structure for the water flow channel of the guide plate in an AEM electrolyzer. Background Technology

[0002] AEM (Anion Exchange Membrane) water electrolysis for hydrogen production is a technology that generates hydrogen through the electrolysis of water. Its core lies in using anion exchange membranes as electrolytes and combining them with non-precious metal catalysts to reduce the cost of hydrogen production. AEM water electrolysis for hydrogen production uses an electrolysis device to decompose water molecules under voltage drive. Hydrogen is produced at the cathode and oxygen at the anode. The anion exchange membrane only allows hydroxide ions (OH⁻) to pass through, preventing direct contact between hydrogen and oxygen and ensuring the safe conduct of the reaction.

[0003] A prior patent (publication number: CN220265866U) discloses an AEM (Automatic Electrolysis) water electrolysis hydrogen production bipolar plate, comprising a bipolar alloy plate. A cathode panel and an anode panel are respectively provided on both sides of the bipolar alloy plate. A first flow channel and a second flow channel are respectively formed inside the cathode panel and anode panel. An oxygen outlet and a second electrolyte inlet are respectively provided at both ends of the cathode panel, and a first electrolyte inlet and a hydrogen outlet are respectively provided at both ends of the anode panel. By employing a dual-flow channel design with a first and second flow channel, the gas-liquid mass transfer rate in the bipolar plate region is improved. The compact design and efficient spine-to-back ratio do not affect the contact resistance between components. The design increases the contact area of ​​the electrolyte between the bipolar alloy plate and the diffusion layer, reducing the diffusion resistance of the electrolyte-gas exchange. The first and second flow channels achieve good gas-liquid flow while also considering the contact resistance between the electrode plate and the gas diffusion layer.

[0004] However, the above technical solutions still have certain drawbacks. The electrolytic cell guide plate adopts a traditional S-shaped flow channel design, with a 90-degree right-angle bend at the flow channel bend. According to fluid mechanics, the high-viscosity alkaline solution will generate significant turbulence when flowing through this point, making the single pressure drop at the right-angle bend potentially ≥2.5 kPa. Since there are many bends in the flow channel, the overall pressure drop will continuously accumulate, causing the fluid to be unable to flow smoothly inside the flow channel. Furthermore, the hydrogen or oxygen at the electrolysis site flows and is discharged inside the guide plate in the form of bubbles. However, in the existing technology, due to the small diameter of the flow channel, the bubbles are easily adsorbed inside the flow channel and cannot be discharged, resulting in low efficiency of the entire reaction. Therefore, an optimized structure for the water flow channel of the AEM electrolytic cell guide plate is proposed. Utility Model Content

[0005] Based on this, the purpose of this utility model is to provide an optimized structure for the water flow channel of the guide plate in an AEM electrolyzer, so as to solve the technical problems mentioned in the background.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an optimized structure for the water flow channel of an AEM electrolytic cell guide plate, comprising two sets of guide plates, with a sealing gasket clamped and fixed between the two sets of guide plates;

[0007] The guide plate includes a base plate, and the outer wall of the base plate is provided with flow channels. The flow channels are distributed in an S-shape on the outer wall of the base plate. At least three sets of guide ribs are fixed at the front, middle and rear sections of the flow channel corners. The guide ribs are fixed at the bottom of the flow channel. The height of the guide ribs is one-fifth of the depth of the flow channel. The guide ribs have an arrow-shaped streamlined structure.

[0008] As a preferred technical solution, an AEM membrane is sleeved in the middle of the sealing gasket, and a set of catalysts is attached to both sides of the AEM membrane. The two sets of catalysts are respectively attached to the outer wall of a set of substrates, and the position of the catalysts matches the flow channel.

[0009] As a preferred technical solution, the corners of the flow channel are rounded and chamfered, with the large chamfer radius being 1mm and the small chamfer radius being 0.5mm.

[0010] As a preferred technical solution, the sidewall of the substrate is provided with a water inlet hole, which is connected to one end of the flow channel, and the connection between the water inlet hole and the flow channel is a funnel-shaped opening.

[0011] As a preferred technical solution, the sidewall of the substrate is provided with a water outlet located next to the water inlet, the water outlet being connected to the other end of the flow channel, and the connection between the water outlet and the flow channel is an inverted funnel-shaped opening.

[0012] As a preferred technical solution, a set of fixing holes are provided through the four corners of the outer wall of the substrate, and the substrate is made of 304 stainless steel.

[0013] In summary, the present invention has the following main advantages:

[0014] 1. In this invention, during the reaction process, bubbles come into contact with the tip of the guide rib at the bend of the flow channel, causing large bubbles to split into multiple small bubbles. Furthermore, multiple sets of guide ribs are provided at the front, middle, and rear ends of the bend of the flow channel to prevent small bubbles from merging into large bubbles at the bend of the flow channel. This prevents large bubbles from being adsorbed and blocked inside the flow channel, ensuring the efficiency of bubble discharge. In addition, the height of the guide ribs is low, avoiding excessive obstruction of fluid flow by the guide ribs.

[0015] 2. This utility model avoids right-angle turbulence inside the flow channel by setting the bends of the flow channel to a rounded chamfer, thus avoiding kinetic energy loss. Since there are many bends in the entire flow channel, the technical solution allows the fluid to flow more smoothly inside the flow channel compared to the prior art. Furthermore, the connection between the water inlet and outlet holes and the flow channel is designed as a funnel-shaped opening, which utilizes the Venturi effect and negative pressure suction effect to optimize the flow field distribution, improve the uniformity of flow velocity, and reduce pressure drop, thereby further improving the working efficiency of the entire electrolytic cell. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the AEM electrolytic cell of this utility model;

[0017] Figure 2 This is a schematic diagram of the explosion mechanism of the AEM electrolytic cell of this utility model;

[0018] Figure 3 This is a schematic diagram of the overall structure of the guide plate of this utility model;

[0019] Figure 4 This is a schematic diagram of the cross-sectional structure of the water inlet hole of this utility model;

[0020] Figure 5 For the present utility model Figure 4 A schematic diagram of the enlarged structure of point A;

[0021] Figure 6 This is a schematic diagram of the cross-sectional structure of the water outlet of this utility model.

[0022] In the diagram: 1. Deflector plate; 2. Sealing gasket; 3. AEM membrane; 4. Catalyst;

[0023] 101. Substrate; 102. Flow channel; 103. Water inlet hole; 104. Water outlet hole; 105. Guide rib. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] The embodiments of this utility model will be described below based on its overall structure.

[0026] An optimized structure for the water flow channel of the guide plate in an AEM electrolyzer, such as... Figures 1 to 6 As shown, it includes two sets of guide plates 1, and a sealing gasket 2 is clamped and fixed between the two sets of guide plates 1;

[0027] The flow guide plate 1 includes a substrate 101. A flow channel 102 is formed on the outer wall of the substrate 101. The flow channel 102 is distributed in an S-shape on the outer wall of the substrate 101. At least three sets of flow guide ribs 105 are fixed at the front, middle and rear sections of the corner of the flow channel 102. The flow guide ribs 105 are fixed at the bottom end of the flow channel 102. The height of the flow guide ribs 105 is one-fifth of the depth of the flow channel 102. The flow guide ribs 105 have a streamlined arrow-shaped structure. An AEM membrane 3 is sleeved in the middle of the sealing gasket 2. A set of catalysts 4 are attached to both sides of the AEM membrane 3. The two sets of catalysts 4 are attached to the outer wall of a set of substrates 101. The position of the catalysts 4 matches the flow channel 102.

[0028] In operation, the solution simultaneously enters the flow channel 102 through the inlet holes 103 on both sets of substrates 101. After the reaction, the electrolyte and oxygen are discharged through the outlet holes 104 on one set of substrates 101, and the electrolyte and hydrogen are discharged through the outlet holes 104 on the other set of substrates 101. The flow channel 102 is S-shaped, allowing sufficient reaction time for the solution after entering the electrolytic cell. The AEM electrolytic cell uses a 30-50 wt% high-concentration alkaline solution as the working medium, and the dynamic viscosity can reach 5-8 at 25°C. The alkaline solution has a conductivity of mPa·s (approximately 5-8 times that of water), and its conductivity changes non-linearly with increasing concentration. The flow field distribution is sensitive to the concentration gradient, which prevents hydrogen or oxygen bubbles generated during the reaction from being discharged smoothly from the outlet hole 104. The guide rib 105 in this application has an arrow-shaped streamlined structure and is located at the bend in the flow channel 102 where bubble blockage is most likely to occur. This allows the bubbles to break into multiple smaller bubbles after contacting the guide rib 105, thereby enabling these bubbles to be discharged more smoothly, reducing the bubble retention rate, and improving the electrolysis efficiency.

[0029] Please refer to this carefully. Figure 2 , Figure 3 , Figure 4 and Figure 6 The corners of the flow channel 102 are rounded and chamfered. The large chamfer radius of the flow channel 102 is 1 mm and the small chamfer radius is 0.5 mm. A water inlet hole 103 is provided on the side wall of the substrate 101. The water inlet hole 103 is connected to one end of the flow channel 102. The connection between the water inlet hole 103 and the flow channel 102 is a funnel-shaped opening. A water outlet hole 104 is provided on the side wall of the substrate 101 next to the water inlet hole 103. The water outlet hole 104 is connected to the other end of the flow channel 102. The connection between the water outlet hole 104 and the flow channel 102 is an inverted funnel-shaped opening. A set of fixing holes is provided through the four corners of the outer wall of the substrate 101. The substrate 101 is made of 304 stainless steel.

[0030] By designing the connection between the inlet hole 103 and the outlet hole 104 and the flow channel 102 as a funnel-shaped opening, a Venturi effect is generated at the connection between the inlet hole 103 and the flow channel 102, and a negative pressure suction effect is generated at the connection between the outlet hole 104 and the flow channel 102. This eliminates the flow dead zone at the connection between the inlet hole 103 and the outlet hole 104 and the flow channel 102. The rounded corner design at the bend of the flow channel 102 allows the fluid and air bubbles to flow more smoothly at the bend, avoiding the pressure drop of the fluid inside the flow channel 102 at the bend. This reduces the pressure difference between the inlet hole 103 and the outlet hole 104, reduces kinetic energy loss, and makes the water flow distribution in the guide plate 1 more uniform, further improving the electrolysis efficiency.

[0031] In use, during the reaction process, the bubbles come into contact with the tip of the guide rib 105 at the bend of the flow channel 102, causing the large bubbles to split into multiple small bubbles. Multiple sets of guide ribs 105 are provided at the front, middle, and rear ends of the bend of the flow channel 102 to prevent small bubbles from merging into large bubbles at the bend of the flow channel 102, thereby preventing large bubbles from being adsorbed and blocked inside the flow channel 102, ensuring the efficiency of bubble discharge. In addition, the guide ribs 105 are relatively low in height, avoiding excessive obstruction of fluid flow by the guide ribs 105. The parts of this device not mentioned are the same as or can be implemented using existing technology.

[0032] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. An optimized structure for the water flow channel of an AEM electrolyzer guide plate, comprising two sets of guide plates (1), characterized in that: A sealing gasket (2) is clamped and fixed between the two sets of guide plates (1); The guide plate (1) includes a base plate (101). The outer wall of the base plate (101) is provided with a flow channel (102). The flow channel (102) is distributed in an S-shape on the outer wall of the base plate (101). At least three sets of guide ribs (105) are fixed at the front, middle and rear sections of the corner of the flow channel (102). The guide ribs (105) are fixed at the bottom end of the flow channel (102). The height of the guide ribs (105) is one-fifth of the depth of the flow channel (102). The guide ribs (105) have an arrow-shaped streamlined structure.

2. The optimized water flow channel structure of the AEM electrolytic cell guide plate (1) according to claim 1, characterized in that: An AEM membrane (3) is fitted in the middle of the sealing gasket (2). A set of catalysts (4) are attached to both sides of the AEM membrane (3). The two sets of catalysts (4) are attached to the outer wall of a set of substrates (101). The position of the catalysts (4) matches the flow channel (102).

3. The optimized water flow channel structure of the AEM electrolytic cell guide plate (1) according to claim 1, characterized in that: The corners of the flow channel (102) are rounded and chamfered. The large chamfer radius of the flow channel (102) is 1 mm and the small chamfer radius is 0.5 mm.

4. The optimized water flow channel structure of the AEM electrolytic cell guide plate (1) according to claim 1, characterized in that: The sidewall of the substrate (101) is provided with a water inlet hole (103), which is connected to one end of the flow channel (102). The connection between the water inlet hole (103) and the flow channel (102) is a funnel-shaped opening.

5. The optimized water flow channel structure of the AEM electrolytic cell guide plate (1) according to claim 1, characterized in that: The sidewall of the substrate (101) is provided with a water outlet (104) located next to the water inlet (103). The water outlet (104) is connected to the other end of the flow channel (102). The connection between the water outlet (104) and the flow channel (102) is an inverted trumpet-shaped opening.

6. The optimized water flow channel structure of the AEM electrolytic cell guide plate (1) according to claim 1, characterized in that: The substrate (101) has a set of fixing holes through the four corners of its outer wall, and the substrate (101) is made of 304 stainless steel.

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