Bipolar plate runner structure suitable for water electrolysis hydrogen production

Abstract

The bipolar plate runner structure comprises an inlet pipe, a plurality of inner main pipes, a plurality of inner branch pipes and an outlet pipe, and the inner main pipes comprise a first main pipe and a second main pipe; the inlet pipe is communicated with the first main pipe, the first main pipe is respectively communicated with the plurality of inner branch pipes, the other ends of the inner branch pipes connected with the same first main pipe are communicated with the same second main pipe, and the other end of the second main pipe is communicated with the outlet pipe; the inner main pipes are arranged at equal intervals, and main pipe area ridges are formed among the inner main pipes; the inner branch pipes are arranged at equal intervals, and branch pipe area ridges are formed between the inner branch pipes. The structure layout is compact, the water distribution uniformity is excellent, the uniform mass transfer in the bipolar plate is realized, the electrolytic performance of the electrolytic bath is ensured, and the industrial application requirements of subsequent PEM high current density and large-scale hydrogen production are met.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen production technology through water electrolysis, and in particular to a bipolar plate flow channel structure suitable for hydrogen production through water electrolysis. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, is receiving increasing attention. Among the various methods, using renewable energy sources such as solar and wind power for water electrolysis to produce hydrogen is one of the best ways to achieve green hydrogen production. Water electrolysis uses water as a raw material, which is widely available. Furthermore, the electrolysis produces hydrogen and oxygen, and the hydrogen-oxygen reaction can generate water again, making it recyclable and pollution-free, thus possessing broad development prospects.

[0003] Among various water electrolysis hydrogen production technologies, proton exchange membrane (PEM) water electrolysis is favored over traditional alkaline water electrolysis due to its stronger adaptability to the fluctuations in renewable energy power generation. Furthermore, PEM water electrolysis hydrogen production devices also possess advantages such as compact structure, relatively small size, good operability, and high safety, making PEM water electrolysis hydrogen production of significant research value and promising application prospects.

[0004] However, the development of high-power PEM water electrolysis hydrogen production equipment currently faces difficulties, especially in the high current density stage, where severe voltage loss leads to a significant reduction in electrolysis efficiency. This voltage loss is mainly attributed to an unreasonable flow channel structure design, resulting in insufficient mass transfer within the electrolytic cell, which in turn affects the electrode reactions. Among these factors, the uniformity of water supply within the bipolar plate flow field becomes a key factor restricting electrolysis performance and stability.

[0005] Currently, there are several publicly disclosed solutions for the flow channel structure of PEM water electrolysis bipolar plates for hydrogen production. For example, patent number CN202211538298.2 discloses a PEM water electrolysis bipolar plate and its preparation method. By using low-cost stainless steel plates, a functional coating is used to form the flow channel ridge of the bipolar plate, improving the conductivity of the bipolar plate and thus enhancing the overall performance of the water electrolysis bipolar plate. Patent number CN202211538214.5 discloses a flow field structure combining trapezoidal and rectangular shapes, achieving rapid gas discharge by setting rectangular and trapezoidal flow channels. However, existing publicly disclosed solutions lack consideration for uniform flow distribution and uniform mass transfer within the bipolar plate. The long-term stability and reliability of the electrolyzer are still insufficient, failing to meet the requirements of high electrical density and large-scale hydrogen production industrial applications. Utility Model Content

[0006] To address the aforementioned issues, this invention provides a bipolar plate flow channel structure suitable for hydrogen production via water electrolysis. It designs an inner main pipe and inner branch pipe structure, and based on this structure, designs the cross-sectional area and flow channel / ridge ratio of the inner main pipe and inner branch pipe. Furthermore, it designs the pressure drop relationship between the inner main pipe and inner branch pipe, achieving uniform flow distribution and mass transfer within the bipolar plate. This improves the performance of the electrolyzer and meets the application requirements of high electrical density and large-scale water electrolysis for hydrogen production using PEM.

[0007] This utility model provides a bipolar plate flow channel structure suitable for hydrogen production by water electrolysis, and the specific technical solution is as follows:

[0008] It includes an inlet pipe, several inner main pipes, several inner branch pipes, and an outlet pipe, wherein the inner main pipes include a first main pipe and a second main pipe;

[0009] The inlet pipe is connected to the first main pipe, the first main pipe is connected to a plurality of the inner branch pipes, the other end of each of the inner branch pipes connected to the same first main pipe is connected to the same second main pipe, and the other end of the second main pipe is connected to the outlet pipe.

[0010] The inner main pipes are arranged at equal intervals, and the inner main pipes together form the ridge of the main pipe area; the inner branch pipes are arranged at equal intervals, and the inner branch pipes together form the ridge of the branch pipe area.

[0011] Furthermore, the bipolar plate flow channel structure is centrally symmetrical, the inner main pipe is an L-shaped structure, the first main pipe and the centrally symmetrical second main pipe have the same structure, and the inner branch pipe is a straight pipe structure.

[0012] Furthermore, the inner main tube has an arc-shaped structure at the connection between the inner branch tube and the bipolar plate.

[0013] Furthermore, the bottom end face of the inner main pipe is flush with the bottom end face of the inner branch pipe, and a chamfer is provided at the connection between the top end faces of the inner main pipe and the inner branch pipe.

[0014] By setting the chamfer, a smooth transition of the flow field is achieved, bubble accumulation is avoided, and gas mass transfer performance is improved.

[0015] Furthermore, the ratio of the cross-sectional area of ​​the inner main pipe to that of the inner branch pipe is 1.2-2.5.

[0016] By designing the main pipe to have a large cross-sectional area and the branch pipes to have a small cross-sectional area, the pressure drop in the branch pipes is increased, the pressure in the main pipe is reduced, and the uniformity of flow distribution is improved. At the same time, the main pipe design with a relatively larger cross-sectional area at the tail end is beneficial for accommodating the gas generated by electrolysis, achieving the requirement of rapid exhaust, improving mass transfer capacity, and enhancing the performance of the electrolytic cell.

[0017] Furthermore, the fluid velocity ratio between the inner main pipe and the inner branch pipe is 1.5:1 to 3:1.

[0018] By reducing the cross-sectional area of ​​the branch pipe, the exhaust performance was improved by increasing the flow velocity within the flow channel.

[0019] Furthermore, the ratio of the flow channel to the ridge of the inner main pipe and the main pipe region ridge is 1:1 to 1:3, and the ratio of the flow channel to the ridge of the inner branch pipe and the branch pipe region ridge is 1:1 to 1:3.

[0020] This flow channel / ridge ratio design reduces contact resistance and ensures conductivity.

[0021] Furthermore, the connection ratio of the inner main pipe to the inner branch pipe is 1:n, where n is 2-10.

[0022] The beneficial effects of this utility model are as follows:

[0023] This invention designs a bipolar plate flow channel structure for use on the anode and cathode sides. Through the cross-sectional ratio of the inner main pipe and inner branch pipes, and the chamfered structure at the connection between the inner main pipe and inner branch pipes, a flow velocity ratio structure is set between the inner main pipe and inner branch pipes based on the chamfered and cross-sectional ratio structures. This reduces the pressure drop in the main pipe and increases the pressure drop in the branch pipes, improving the uniformity of flow distribution. Furthermore, the chamfered structure design achieves a smooth flow field transition, avoids bubble accumulation, and improves gas mass transfer performance. Simultaneously, the ridge ratio structure between the ridge of the main pipe region and the ridge of the branch pipe region reduces contact resistance and improves conductivity. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall bipolar plate flow channel structure of this utility model.

[0025] Figure 2 This is a schematic diagram of the flow distribution of the bipolar plate flow channel structure of this utility model at a current density of 1.5A / cm2.

[0026] Figure 3 This is a schematic diagram of the flow distribution of the bipolar plate flow channel structure of this utility model at a current density of 5A / cm2.

[0027] Explanation of reference numerals in the attached diagram: 1-Inlet pipe, 2-First main pipe, 3-Main pipe area ridge, 4-Inner branch pipe, 5-Branch area ridge, 6-Chamfer, 7-Second main pipe, 8-Outlet pipe. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. The components of the embodiments of the present utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] In the description of the embodiments of this utility model, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly used when the utility model product is in use. These are only for the convenience of describing the utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, the terms "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Example 1

[0032] Embodiment 1 of this utility model discloses a bipolar plate flow channel structure suitable for hydrogen production by water electrolysis, such as... Figure 1 As shown, the details are as follows:

[0033] It includes an inlet pipe 1, several inner main pipes, several inner branch pipes 4 and an outlet pipe 8, wherein the inner main pipes include a first main pipe 2 and a second main pipe 7;

[0034] The inlet pipe 1 is connected to the first main pipe 2, the first main pipe 2 is connected to a plurality of the inner branch pipes 4, the other end of each of the inner branch pipes 4 connected to the same first main pipe 2 is connected to the same second main pipe 7, and the other end of the second main pipe 7 is connected to the outlet pipe 8.

[0035] Specifically, the connection ratio of the inner main pipe to the inner branch pipe 4 is 1:n, where n is 2-10.

[0036] Specifically, the bipolar plate flow channel structure is centrally symmetrical, the inner main pipe is an L-shaped structure, the first main pipe 2 and the centrally symmetrical second main pipe 7 have the same structure, and the inner branch pipe 4 is a straight pipe structure.

[0037] In a preferred embodiment, the inner main tube has an arc-shaped structure at the connection between the inner branch tube 4 and the bipolar plate.

[0038] That is, at the end where the inner main pipe connects to the inner branch pipe 4, an arc-shaped structure is provided on the ridge 3 side of the main pipe area.

[0039] Water used for electrolysis enters the bipolar plate channel from the inlet pipe 1, and enters the first main pipe 2 through the main water distribution area (i.e., the larger rectangular area at the inlet pipe 1). It then enters each inner branch pipe 4 through the first main pipe 2. The water enters the diffusion layer (directly above the inner branch pipe 4) at the bottom of the inner branch pipe 4, and then reaches the membrane electrode side (above the diffusion layer) to undergo an electrolysis reaction. The generated oxygen (anode) or hydrogen (cathode) mixes with the water and enters the second main pipe 7, and flows out from the outlet pipe 8.

[0040] The inner main pipes are arranged at equal intervals, and the inner main pipes together form the main pipe area ridge 3; the inner branch pipes 4 are arranged at equal intervals, and the inner branch pipes 4 together form the branch pipe area ridge 5.

[0041] The main pipe ridge 3 and the branch pipe ridge 5 are mainly used for support and electrical conduction.

[0042] In a preferred embodiment, the bottom end face of the inner main pipe is flush with the bottom end face of the inner branch pipe 4, and a chamfer 6 is provided at the connection between the top end faces of the inner main pipe and the inner branch pipe 4.

[0043] That is, the height from the first main pipe 2 to the inner branch pipe 4 decreases, and the height from the inner branch pipe 4 to the second main pipe 7 increases; the specific structure of the chamfer 6 can be a right-angle step, a chamfer 6 step, or a rounded step;

[0044] The chamfer 6 setting enables a smooth transition of the flow field, avoids bubble accumulation, and improves gas mass transfer performance.

[0045] In a preferred embodiment, the cross-sectional area ratio of the inner main pipe to the inner branch pipe 4 is 1.2-2.5.

[0046] By setting the cross-sectional area relationship between the inner main pipe and the inner branch pipe 4, the pressure drop of the branch pipe is increased and the pressure of the main pipe is reduced, thereby improving the uniformity of flow distribution.

[0047] In a preferred embodiment, the fluid velocity ratio between the inner main pipe and the inner branch pipe 4 is 1.5:1 to 3:1.

[0048] By setting the depth of chamfer 6, the cross-sectional area relationship between the inner main pipe and the inner branch pipe 4 is set, so that the fluid velocity ratio between the inner main pipe and the inner branch pipe 4 is 1.5:1 to 3:1. This achieves the purpose of reducing the pressure drop of the main pipe and increasing the pressure drop of the branch pipe, thus achieving uniform flow distribution. At the same time, since the cross-sectional area of ​​the inner branch pipe 4 is smaller than that of the first main pipe 2, the flow velocity in the flow channel is increased, thereby improving the exhaust performance. The cross-sectional area of ​​the second main pipe 7 at the tail end is designed to be larger than that of the inner branch pipe 4, which is conducive to accommodating the gas generated by electrolysis, achieving the requirement of rapid exhaust, improving mass transfer capacity, and improving the performance of the electrolytic cell.

[0049] In a preferred embodiment, the ratio of the flow channel to the ridge of the inner main pipe and the ridge of the main pipe region 3 is 1:1 to 1:3, and the ratio of the flow channel to the ridge of the inner branch pipe 4 and the ridge of the branch pipe region 5 is 1:1 to 1:3, to ensure conductivity and reduce contact resistance.

[0050] Based on the above bipolar plate flow channel structure, the CFD flow field simulation analysis results under different current densities are as follows: Figure 2 and Figure 3 As shown;

[0051] in, Figure 2 The flow distribution results are shown at a current density of 1.5 A / cm², with the volumetric flow rate distribution deviation for each branch pipe being -3% to 3%. Figure 3 The flow distribution results are shown at a current density of 5 A / cm². The volumetric flow rate distribution deviation of each branch pipe is -7% to 8%. As can be seen from the figure, this structural design achieves the improvement of branch pipe pressure drop and the reduction of main pipe pressure drop, ensuring the uniformity of flow distribution in each branch pipe, realizing a compact structural layout, ensuring efficient and stable electrolysis, and meeting the application requirements of PEM high electrical density and large-scale water electrolysis for hydrogen production.

[0052] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A bipolar plate flow channel structure suitable for hydrogen production by water electrolysis, characterized in that, It includes an inlet pipe, several inner main pipes, several inner branch pipes, and an outlet pipe, wherein the inner main pipes include a first main pipe and a second main pipe; The inlet pipe is connected to the first main pipe, the first main pipe is connected to a plurality of the inner branch pipes, the other end of each of the inner branch pipes connected to the same first main pipe is connected to the same second main pipe, and the other end of the second main pipe is connected to the outlet pipe. The inner main pipes are arranged at equal intervals, and the inner main pipes together form the ridge of the main pipe area; the inner branch pipes are arranged at equal intervals, and the inner branch pipes together form the ridge of the branch pipe area.

2. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 1, characterized in that, The bipolar plate flow channel structure is centrally symmetrical. The inner main pipe is an L-shaped structure. The first main pipe and the centrally symmetrical second main pipe have the same structure. The inner branch pipe is a straight pipe structure.

3. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 1, characterized in that, The inner main tube has an arc-shaped structure at the connection between the inner branch tube and the bipolar plate.

4. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 1, characterized in that, The bottom end face of the inner main pipe is flush with the bottom end face of the inner branch pipe, and a chamfer is provided at the connection between the top end faces of the inner main pipe and the inner branch pipe.

5. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 4, characterized in that, The ratio of the cross-sectional area of ​​the main inner pipe to that of the branch inner pipe is 1.2-2.

5.

6. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 5, characterized in that, The fluid velocity ratio between the main inner pipe and the branch inner pipe is 1.5:1 to 3:

1.

7. The bipolar plate flow channel structure for hydrogen production by water electrolysis according to claim 1, characterized in that, The ratio of the flow channel to the ridge of the inner main pipe and the main pipe region ridge is 1:1 to 1:3, and the ratio of the flow channel to the ridge of the inner branch pipe and the branch pipe region ridge is 1:1 to 1:

3.

8. The bipolar plate flow channel structure suitable for hydrogen production by water electrolysis according to any one of claims 1-7, characterized in that, The connection ratio between the main internal pipe and the branch internal pipe is 1:n, where n is 2-10.

Images