Flow channel structure, design method thereof and electrochemical reactor

Abstract

The invention relates to the technical field of electrochemical reactors, and discloses a flow channel structure, a design method thereof and an electrochemical reactor, the flow channel structure comprises a first main flow channel, a second main flow channel and a third main flow channel, the second main flow channel is used for flowing out circulating fluid; two ends of the branch runners are respectively communicated with the side parts of the first main runner and the second main runner; a guide element extending towards the direction close to the inlets of the branch flow channels is arranged on the side, away from the inlets of the branch flow channels, in the first main flow channel, so that the flow of the circulating fluid shunted into the branch flow channels from the first main flow channel is the same. According to the technical scheme, the guiding element can enable the kinetic energy of the circulating fluid to be reduced when the circulating fluid flows through the guiding element in the extending direction of the first main flow channel, and when the kinetic energy of the circulating fluid at the inlets of the branch flow channels is the same, the flow of the circulating fluid shunted to the branch flow channels by the first main flow channel is the same, so that the effect of uniformly distributing the circulating fluid is achieved.

Description

Technical Field

[0001] This invention relates to the field of electrochemical reactor technology, specifically to a flow channel structure. Furthermore, it relates to a design method for the flow channel structure and an electrochemical reactor. Background Technology

[0002] The advent of the new energy power era has brought tremendous development prospects to the electrochemical industry. Among them, proton exchange membrane (PEM) water electrolysis technology, PEM fuel cell technology, and carbon dioxide electrochemical conversion technology have shown great application potential in chemical industry technologies such as green hydrogen production, hydrogen application, and carbon resource utilization. These technologies typically utilize flow-through electrochemical reactors, which include a continuous reaction medium. The reaction medium can be a gaseous fluid (such as hydrogen in a fuel cell), a liquid fluid (such as H2O in PEM water electrolysis), or a gas-liquid two-phase fluid (such as a CO2 / potassium bicarbonate electrolyte two-phase flow in a carbon dioxide conversion electrolyzer). The fluid enters through an inlet on the electrochemical reactor, undergoes a primary distribution on the flow field at the electrodes, a secondary distribution on the porous transport layer (or diffusion layer), a tertiary distribution on the catalyst layer, and finally, an electrochemical reaction occurs on the catalyst surface to transform the fluid into products.

[0003] On the electrode plates of an electrochemical reactor, flow channels for transporting and distributing fluids are typically provided. These channels consist of interconnected grooves on the electrode plates and can be fabricated by etching, machining, or stamping. Fluid is injected into these channels through openings at fixed positions on the electrode plates, simultaneously transported within the channels to the reaction zone. Finally, the products and circulating fluid flow out through outlets at fixed positions on the electrode plates. Within the flow channel region, since the number of main channels corresponding to the inlet is usually small, a structure where a main channel is divided into multiple branch channels is used to distribute the fluid across the entire flow field on the electrode plate. For example, in a branch channel structure, a main channel branches into several branch channels on one side in its extending direction, with the angle between the branch channel direction and the main channel direction being 90°. This structural design results in the fluid flowing into the main channel having momentum in its extending direction, leading to the last branch channel receiving the most fluid, thus causing non-uniformity in fluid distribution within the flow field. Related studies have demonstrated that for electrochemical reactors, the uniformity of fluid distribution, or the uniformity of fluid velocity distribution within the flow channel, has a crucial impact on the uniformity of reactant supply and Joule heat dissipation, thus significantly affecting the spatial uniformity of the electrochemical reaction and ultimately influencing reactor performance and lifespan. Therefore, achieving uniform fluid distribution is particularly important in structural designs where a single flow channel is divided into multiple channels.

[0004] Currently, existing electrochemical reactors mainly improve the uniformity of fluid distribution by changing the shape of the branch channels and adding flow guiding zones. For example, Chinese patent CN219534563U discloses a bipolar plate, a fuel cell, and an electrolyzer. The bipolar plate includes a common pipe area, a distribution area, a flow field area, and a sealing area. The flow field area includes several flow channels with the same extension direction. Along the extension direction of the flow channels, a single flow channel includes multiple flow channel units. Multiple flow channel units are connected in sequence to form a bent flow channel structure. The flow channel units have a flow channel inclination angle, and the flow channel inclination angles of two adjacent flow channel units are different. While the above technical solution can improve the uniformity of fluid distribution to a certain extent, the flow channel unit in this solution has a bent flow channel structure, and the inclination angles of adjacent flow channel units are not the same. On the one hand, this results in a larger cross-sectional area of ​​the bent flow channel ridge formed between the two flow channel units compared to the cross-sectional area of ​​the straight flow channel ridge, thus reducing the area available for fluid flow and reaction within the electrochemical reactor. On the other hand, the different cross-sectional areas between two adjacent flow channel ridges result in different electron transport velocities when the two adjacent flow channel ridges come into contact with the electrode plate, thereby affecting the reaction results.

[0005] In addition, Chinese patent application CN116314917A discloses a plate distribution area structure, including a plate, with multiple bosses on the distribution area of ​​the plate, and protrusions on the bosses. Chinese patent application CN116417634A discloses a fuel cell plate structure, a bipolar plate, and a fuel cell. This fuel cell plate structure includes a sealed area, a common channel, a distribution area, and a reaction area. Both of these patent applications achieve improved fluid distribution uniformity by setting up a flow distribution area. However, the flow distribution area occupies a significant amount of usable space on the bipolar plate, and it is typically located upstream of the fluid inlet, meaning it is outside the reaction area and cannot affect the process of distributing the main flow channel fluid to the branch channels within the reaction area. Furthermore, for cases where a main flow channel after entering the reaction area branches into multiple branch channels, there is no space available for setting up a flow distribution area. In other words, the technical solutions in the above patent applications can only achieve uniform fluid distribution upstream of the reaction area, but cannot achieve uniform fluid distribution within the reaction area itself. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem of uneven fluid distribution in existing electrochemical reactors, and to provide a flow channel structure, its design method, and an electrochemical reactor. This flow channel structure has the advantage of achieving uniform distribution of fluid flow rate in each branch channel without changing the overall structure of the flow field region or increasing the area of ​​the reaction region.

[0007] To achieve the above objectives, a first aspect of the present invention provides a flow channel structure, including a first main channel for inflow of circulating fluid, a second main channel for outflow of the circulating fluid, and a plurality of branch channels whose two ends are respectively connected to the sides of the first main channel and the second main channel. The first main channel has a guide element provided on its side away from the inlet of the branch channel, extending toward the inlet of the branch channel, so that the flow rate of the circulating fluid diverted from the first main channel into the plurality of branch channels is the same.

[0008] In existing fluid structures, circulating fluid flows into the fluid structure from a first main channel, then branches into multiple branch channels, before converging into a second main channel and finally exiting the fluid structure. When the circulating fluid enters the first main channel, its kinetic energy along the channel's extension direction causes the kinetic energy at the inlet of each branch channel to increase sequentially, resulting in uneven flow rates from the first main channel to the branch channels. This invention addresses this by providing a guide element on the side of the first main channel away from the branch channel inlet. This guide element extends towards the inlet of the branch channel, reducing the cross-sectional area of ​​the circulating fluid as it flows through the guide element. This further reduces the kinetic energy of the circulating fluid as it passes through the guide element. When the kinetic energy of the circulating fluid at the inlet of each branch channel is the same, the flow rates of the circulating fluid branched from the first main channel to the branch channels are equal, thus achieving a uniform distribution of the circulating fluid.

[0009] Optionally, the flow channel structure provided by the present invention further includes a flow channel ridge disposed between two adjacent branch channels.

[0010] Optionally, the guide element is configured to correspond one-to-one with the flow channel ridge.

[0011] Optionally, the two ends of the flow channel ridge are formed with arc-shaped chamfers.

[0012] Optionally, the branch channels are vertically connected to the first main channel, the multiple branch channels have the same width, the multiple channel ridges have the same width, and the guide element has a protrusion at its maximum length extending towards the inlet of the branch channel.

[0013] Optionally, the protrusion height of the protrusion is 0-0.8 times the width of the first main channel.

[0014] Optionally, when there are multiple guide elements, the protrusion height of the protrusion gradually increases along the flow direction of the circulating fluid in the first main channel.

[0015] Optionally, along the direction of the circulating fluid flow, the protrusion height of the protrusion increases sequentially in an arithmetic sequence.

[0016] Optionally, the protrusion is disposed between the center line of the corresponding branch channel and the center line of the adjacent channel ridge.

[0017] Optionally, the distance between the protrusion and the centerline of the corresponding branch channel satisfies at least one of the following two conditions:

[0018] In scenario one, there are two branch channels, one guide element, and the protrusion is located in the direction of the centerline extension of the corresponding branch channel.

[0019] Scenario 2: The number of branch channels is greater than two, and the distance between the nth protrusion along the direction of circulating fluid flow and the centerline of the corresponding nth branch channel is:

[0020]

[0021] In the above formula, D1 is the width of the branch channel.

[0022] D2 is the width of the flow channel ridge.

[0023] N is the number of the branch channels.

[0024] n is 1, 2, 3, ..., N-1.

[0025] Optionally, the guide element is symmetrical about the vertical line perpendicular to the first main channel where the protrusion is located.

[0026] Optionally, the guide element is semi-cylindrical.

[0027] Optionally, the flow channel structure provided by the present invention further includes a front flow channel and a rear flow channel respectively disposed upstream of the first main flow channel and downstream of the second main flow channel.

[0028] A second aspect of the present invention provides a flow channel structure design method, comprising the following steps:

[0029] Based on the above flow channel structure, a geometric model is established in numerical simulation software;

[0030] Input the initial conditions, boundary conditions, and physical property parameters of the circulating fluid;

[0031] Determine the flow model;

[0032] The geometric model is meshed;

[0033] Simulation calculations were performed to obtain the flow field distribution in the geometric model;

[0034] Based on the flow field distribution, adjust the position and shape of the guiding elements in the geometric model;

[0035] Repeat the above steps until the flow field distribution is uniform;

[0036] The flow channel structure is adjusted according to the placement and shape of the guide elements in the geometric model.

[0037] A third aspect of the present invention provides an electrochemical reactor comprising an electrode plate having the above-described flow channel structure. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of one embodiment of an electrochemical reactor electrode plate disclosed in the prior art;

[0039] Figure 2 yes Figure 1 Enlarged schematic diagram of the flow channel from the front end to the parallel flow channel region;

[0040] Figure 3 yes Figure 1 A schematic diagram of the flow channel structure;

[0041] Figure 4 yes Figure 3 An enlarged schematic diagram of the fluid distribution area;

[0042] Figure 5 yes Figure 3 A schematic diagram of fluid velocity distribution;

[0043] Figure 6 yes Figure 3 A schematic diagram of fluid temperature distribution;

[0044] Figure 7 This is a schematic diagram of another implementation of the flow channel structure in the prior art;

[0045] Figure 8 yes Figure 7 An enlarged schematic diagram of the fluid distribution area;

[0046] Figure 9 yes Figure 7 A schematic diagram of fluid velocity distribution;

[0047] Figure 10 yes Figure 7 A schematic diagram of fluid temperature distribution;

[0048] Figure 11 This is a schematic diagram of one embodiment of the flow channel structure disclosed in this invention;

[0049] Figure 12 yes Figure 11 A schematic diagram of fluid velocity distribution;

[0050] Figure 13 yes Figure 11 A schematic diagram of fluid temperature distribution;

[0051] Figure 14 This is a schematic diagram of another embodiment of the flow channel structure disclosed in this invention;

[0052] Figure 15 yes Figure 14 A schematic diagram of fluid velocity distribution;

[0053] Figure 16 yes Figure 14 A schematic diagram of fluid temperature distribution;

[0054] Figure 17 This is a schematic diagram of another embodiment of the flow channel structure disclosed in this invention;

[0055] Figure 18 This is a schematic diagram of another embodiment of the flow channel structure disclosed in this invention;

[0056] Explanation of reference numerals in the attached figures

[0057] 1-Front-end flow channel; 2-Fluid distribution area; 21-First main flow channel; 22-Branch flow channel; 3-Parallel flow channel area; 4-Flow channel confluence area; 5-Rear-end flow channel; 6-Circulating fluid inlet; 71-First guide element; 72-Second guide element; 73-Third guide element; 8-Circulating fluid outlet. Detailed Implementation

[0058] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0059] In this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not 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 limiting this invention.

[0060] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] Existing electrochemical mobile phase reactors, such as membrane electrode reactors used for testing / evaluation / production (evaluation / production), proton exchange membrane water electrolysis, proton exchange membrane fuel cells, and anion exchange membrane electrochemical reactors, often involve a structure where fluid is distributed from one channel to multiple channels in the gas / liquid flow field distribution zone on the reactor's electrodes. For example, combined with... Figures 1-10 As shown, the flow channel structure of the existing electrochemical reactor includes a circulating fluid inlet 6, a front flow channel 1, a fluid distribution zone 2, a flow channel confluence zone 4, a rear flow channel 5, and a circulating fluid outlet 8, which are connected sequentially along the flow direction of the circulating fluid. (The last part is a repetition of the first part and can be omitted.) Figure 3 and Figure 4 As shown, the circulating fluid flows into the fluid distribution zone 2 through the front channel 1. The fluid distribution zone 2 includes a first main channel 21 arranged along the extension direction of the front channel 1 and multiple branch channels 22 perpendicularly connected to the side of the first main channel 21. The multiple branch channels 22 can be arranged in parallel to form a parallel channel zone 3. Therefore, the circulating fluid is distributed into the multiple branch channels 22 through the first main channel 21, and then converges into the second main channel in the channel confluence zone 4, and flows out of the reaction zone of the electrochemical reactor through the rear channel 5 and the circulating fluid outlet 8, respectively. During the above flow process, when the circulating fluid flows into the first main channel 21 from the front channel 1, the circulating fluid has kinetic energy flowing along the extension direction of the first main channel 21, so the kinetic energy of the circulating fluid at the inlet of each branch channel 22 increases sequentially along the flow direction of the circulating fluid. Figure 4 As shown, within the first main channel 21, the circulating fluid possesses kinetic energy flowing from left to right, causing the kinetic energy of the circulating fluid at the inlet of each branch channel 22 to increase sequentially along the left-to-right extension direction, thereby causing the fluid flow rate into each branch channel 22 to increase sequentially, such as... Figure 5 and Figure 6 As shown, according to the simulation results of the numerical simulation software, along the direction of extension from left to right, the flow rate of the fluid flowing into each branch channel 22 increases sequentially, which leads to the flow velocity and temperature in each branch channel 22 also increasing sequentially, ultimately affecting the chemical reaction in the electrochemical reactor.

[0063] The first aspect of the present invention provides a flow channel structure, referring toFigures 11 to 18 As shown, the flow channel structure includes: a first main channel 21 for the inflow of circulating fluid; a second main channel for the outflow of circulating fluid; and a plurality of branch channels 22, each having its two ends connected to the sides of the first main channel 21 and the second main channel respectively; wherein, a guide element is provided on the side of the first main channel 21 away from the inlet of the branch channel 22, extending toward the inlet of the branch channel 22, so that the flow rate of the circulating fluid diverted from the first main channel 21 to the plurality of branch channels 22 is the same.

[0064] The present invention provides a guide element on the side of the first main channel 21 away from the inlet of the branch channel 22. The guide element extends toward the inlet of the branch channel 22, so that the flow cross-sectional area of ​​the circulating fluid is reduced when it flows through the guide element along the extension direction of the first main channel 21. This reduces the kinetic energy of the circulating fluid as it passes through the guide element. When the kinetic energy of the circulating fluid at the inlet of each branch channel 22 is the same, the flow rate of the circulating fluid diverted from the first main channel 21 to each branch channel 22 is the same, thereby achieving the effect of uniform distribution of the circulating fluid.

[0065] Optionally, the flow channel structure provided by the present invention further includes a flow channel ridge disposed between two adjacent branch channels 22, that is, combined with Figure 11 and Figure 14 As shown, the position of the branch channel 22 is defined by two adjacent channel ridges or the sidewalls of the channel structure and the channel ridges.

[0066] Furthermore, the two ends of the flow channel ridge form an arc-shaped chamfer, that is, as shown in the image. Figure 11 and Figure 14 As shown, the flow channel ridges form arc-shaped chamfers at both ends of the inlet and outlet of the branch channel 22, which can prevent the circulating fluid from being disturbed when flowing into or out of the branch channel 22.

[0067] Optionally, the guide elements are configured to correspond one-to-one with the flow channel ridges, as shown in the reference. Figure 11 and Figure 14 As shown, the number of guide elements is the same as the number of flow channel ridges, and this number is one less than the number of branch channels 22. Furthermore, along the flow direction of the circulating fluid within the first main flow channel 21, i.e., along... Figure 11 and Figure 14 From left to right, the nth guide element can be positioned between the nth branch channel and the nth channel ridge, where n can be 0, 1, 2, ...

[0068] Optionally, each branch channel 22 can be arranged at an angle to the first main channel 21, that is, the angle between the centerline of each branch channel 22 and the centerline of the first main channel 21 can be set to 0-90°. Of course, the widths of each branch channel 22 can be different, and the widths of each channel ridge can also be different.

[0069] According to one embodiment of the flow channel structure of the present invention, referring to Figure 11 and Figure 14 As shown, the branch channel 22 is vertically connected to the first main channel 21, and the length, width and height of the multiple branch channels 22 are the same, the length, width and height of the multiple channel ridges are the same, and the guide element forms a protrusion at the maximum length extending in the direction close to the inlet of the branch channel 22.

[0070] Optionally, the protrusion height of the protrusion is 0-0.8 times the width of the first main channel 21, so that there is a certain gap between the protrusion and the corresponding channel ridge or branch channel 22 inlet, which facilitates the installation of the guide element in the first main channel 21.

[0071] Optionally, when there are two branch channels 22, namely a first branch channel and a second branch channel distributed sequentially along the flow direction of the circulating fluid in the first main channel 21, and the number of guide elements and flow channel ridges is one, the guide element is arranged directly opposite the first branch channel, that is, the protrusion of the guide element is located in the direction of the extension of the centerline of the first branch channel. The protrusion height of the protrusion can be adjusted according to the actual flow field distribution, so that the fluid flow rate distributed from the first main channel 21 to the first branch channel and the second branch channel is the same.

[0072] Optionally, when the number of branch channels 22 exceeds two and the number of guide elements and flow channel ridges exceeds one, the protrusion height of the protrusion gradually increases along the flow direction of the circulating fluid in the first main channel 21. This causes the size of the flow channel formed by the protrusion and the side of the first main channel 21 near the branch channel 22 to gradually decrease along the flow direction of the circulating fluid in the first main channel 21. Consequently, the kinetic energy loss of the circulating fluid gradually increases when it flows through the flow channel, which is beneficial for achieving uniform distribution of the circulating fluid from the first main channel 21 to each branch channel 22.

[0073] According to one embodiment of the flow channel structure of the present invention, along the flow direction of the circulating fluid in the first main flow channel 21, the protrusion height of the protrusion increases sequentially in an arithmetic sequence, while the protrusion height of the last guide element is not greater than 0.8 of the width of the first main flow channel 21, so as to achieve uniform fluid distribution while ensuring that the guide element is easy to install.

[0074] As mentioned above, the protruding part of the guide element is positioned between the centerline of the corresponding branch channel 22 and the centerline of the adjacent channel ridge. When there are two branch channels 22 and one guide element and one channel ridge, the protruding part is positioned along the extension direction of the centerline of the corresponding branch channel 22, i.e., along the direction of circulating fluid flow. The protruding part is positioned along the extension direction of the centerline of the first branch channel 22. When there are more than three branch channels 22, the distance between the nth protruding part along the direction of circulating fluid flow and the centerline of the corresponding nth branch channel 22 is:

[0075]

[0076] In the above formula, D1 is the width of branch channel 22.

[0077] D2 is the width of the flow channel ridge.

[0078] N is the number of tributary channels 22.

[0079] n is 1, 2, 3, ..., N-1.

[0080] Optionally, the shape of the guide element can be arbitrary, as long as the protrusion height and position of the protrusion meet the above-described settings. For example, refer to... Figure 17 As shown, the guide element is a triangle, and the vertex of the triangle is a protrusion.

[0081] Of course, the guide element can be asymmetrically arranged with respect to the vertical line perpendicular to the first main channel 21 where the protrusion is located, for example, referring to... Figure 18 As shown, the first guide element 71, the second guide element 72 and the third guide element 73 are respectively asymmetrically arranged about the vertical line perpendicular to the first main channel 21 where their protrusions are located.

[0082] Alternatively, according to one embodiment of the flow channel structure of the present invention, the guide element is symmetrical about the perpendicular line perpendicular to the first main flow channel 21 where the protrusion is located. Further, referring to... Figure 11 and Figure 14 As shown, the guide element is semi-cylindrical, which helps to reduce the disturbance when the circulating fluid comes into contact with the guide element.

[0083] Furthermore, the flow channel structure provided by this invention also includes a front flow channel 1 and a rear flow channel 5 respectively located upstream of the first main flow channel 21 and downstream of the second main flow channel. The front flow channel 1 is arranged in a direction parallel to the direction of the first main flow channel 21, and the rear flow channel 5 is arranged in a direction parallel to the direction of the second main flow channel. Simultaneously, the inlet of the front flow channel 1 is connected to the circulating fluid inlet 6 of the flow channel structure, and its outlet is connected to the inlet of the first main flow channel 21. The inlet of the rear flow channel 5 is connected to the outlet of the second main flow channel, and its outlet is connected to the inlet of the circulating fluid outlet 8 of the flow channel structure.

[0084] A second aspect of the present invention provides a flow channel structure design method, comprising the following steps:

[0085] Based on the above-described flow channel structure, a geometric model is established in numerical simulation software. Specifically, this geometric model includes a front flow channel 1, a fluid distribution area 2, a flow channel confluence area 4, a rear flow channel 5, and a circulating fluid outlet 8, arranged sequentially along the direction of the circulating fluid flow. The fluid distribution area 2 includes a first main flow channel 21 and multiple branch flow channels 22. The flow channel confluence area 4 includes a second main flow channel. The two ends of the multiple branch flow channels 22 are perpendicularly connected to the sides of the first main flow channel 21 and the second main flow channel, respectively. The multiple branch flow channels 22 have the same shape and size, and a flow channel ridge is formed between any two branch flow channels 22. A guide element extending towards the inlet of the branch flow channel 22 is provided on the side of the first main flow channel 21 away from the inlet of the branch flow channel 22. The guide element corresponds one-to-one with the flow channel ridge.

[0086] Input the initial conditions, boundary conditions, and physical property parameters of the circulating fluid. The initial conditions include the circulating fluid inflow temperature T; the boundary conditions include the flow rate Q at the inlet of the first main channel 21 and the pressure P at the outlet of the second main channel; and the physical property parameters of the circulating fluid include viscosity μ and density ρ.

[0087] Determine the flow model. Calculate the Reynolds number Re for the circulating fluid flow within the first main flow channel 21, where Re = ρvd / μ, and v is the average velocity of the circulating fluid within the first main flow channel 21, which can be calculated from the flow rate Q at the inlet of the first main flow channel 21 and the equivalent pipe diameter D of the first main flow channel 21. Based on the calculated Reynolds number Re, if Re > 2000, a turbulent flow model is used for calculation, such as the Spalart-Allmaras model in the RANS model; if Re < 2000, a laminar flow model is used for calculation.

[0088] The geometric model is meshed. A free tetrahedral mesh can be used to mesh the geometric model. Furthermore, local mesh refinement can be applied to narrow sections of the circulating fluid flow channel cross-section, for example, by using a smaller free tetrahedral mesh in these narrow sections. Mesh independence is then verified in the calculation results. Alternatively, other mesh shapes, such as cubes, can also be used to mesh the geometric model.

[0089] Simulation calculations are performed to obtain the flow field distribution in the geometric model. According to one embodiment of the flow channel structure design method provided by this invention, the simulation software used is Comsol Multiphysics, the circulating fluid is water, and the flow rate Q at the inlet of the first main flow channel 21 is 0.13 cm³. 3The circulating fluid inflow temperature T is 298.15 K, and the pressure P at the outlet of the second main channel is 0 Pa. The flow model is laminar (Reynolds number Re < 2000), and the geometric model is meshed using a free tetrahedral grid. Based on the above parameters, CFD calculations are performed to obtain the flow field distribution map of the numerical model, which may include a velocity distribution map and a temperature distribution map.

[0090] Based on the above flow field distribution, adjust the position and shape of the guide elements in the geometric model;

[0091] Repeat the above steps until the resulting flow field distribution is uniform, thereby determining the design scheme for the placement and shape of the guide element;

[0092] Adjust the actual flow channel structure according to the location and shape of the guide elements in the above geometric model.

[0093] The beneficial effects of the flow channel structure of the present invention will be specifically described below using flow channel structures with 1-to-3 and 1-to-4 branches, i.e., flow channel structures with 3 branch channels 22 and 4 branch channels 22.

[0094] Example 1

[0095] Reference Figure 11 As shown, according to one embodiment of the flow channel structure of the present invention, the flow channel structure is a 1-to-3 type flow channel structure, that is, the fluid distribution area 2 includes a first main flow channel 21 and three branch flow channels 22 perpendicularly connected to the first main flow channel 21. The three branch flow channels 22 are a first branch flow channel, a second branch flow channel, and a third branch flow channel arranged sequentially along the flow direction of the circulating fluid. The width of the first main flow channel 21 and the three branch flow channels 22 are all 1 mm, and the depth of each is 1 mm. A first flow channel ridge is formed between the first branch flow channel and the second branch flow channel, and a second flow channel ridge is formed between the second branch flow channel and the third branch flow channel. The width of the first flow channel ridge and the second flow channel ridge is 1 mm. Figure 11As shown, the flow channel structure also includes a first guide element 71 and a second guide element 72. Both the first and second guide elements 71 and 72 are semi-cylindrical. The radius of the first guide element 71 (i.e., the protrusion height of the protrusion of the first guide element 71) is 0.36 mm, and the center of the first guide element 71 is located in the extension direction of the centerline of the first branch flow channel (i.e., the protrusion of the first guide element 71 is located in the extension direction of the centerline of the first branch flow channel). The radius of the second guide element 72 (i.e., the protrusion height of the second guide element 72) is 0.6 mm, and the distance between the center of the second guide element 72 and the centerline of the second branch flow channel (i.e., the distance between the protrusion of the second guide element 72 and the centerline of the second branch flow channel) is 1 mm. Based on the above flow channel structure, a corresponding geometric model is established in Comsol Multiphysics software. Using the above flow channel structure design method, the corresponding velocity distribution map and temperature distribution map are obtained in Comsol Multiphysics software, as shown below. Figure 12 As shown, the flow velocities at corresponding positions in the first, second, and third branches are the same, respectively. Figure 13 As shown, the temperatures at corresponding positions in the first, second, and third branch channels are all the same. That is, by providing the first guide element 71 and the second guide element 72 described above, the fluid flow distribution in this 1-to-3 branch channel structure is made uniform.

[0096] Comparative Example 1

[0097] Reference Figure 3 and Figure 4 As shown, the flow channel structure of Comparative Example 1 is a 1-to-3 flow channel structure. The difference between Comparative Example 1 and the flow channel structure of Embodiment 1 is that the flow channel structure in Comparative Example 1 does not have guiding elements. Based on the flow channel structure of Comparative Example 1, a corresponding geometric model is established in Comsol Multiphysics software. Using the aforementioned flow channel structure design method, the corresponding velocity distribution map and temperature distribution map are obtained in Comsol Multiphysics software, as shown below. Figure 5 As shown, the flow velocities at corresponding positions in the first, second, and third branch channels increase sequentially, as follows: Figure 13 As shown, the temperatures at corresponding locations in the first, second, and third branch channels decrease sequentially. This indicates that the flow channel structure in Comparative Example 1 suffers from uneven fluid flow distribution.

[0098] Example 2

[0099] Reference Figure 14As shown, according to one embodiment of the flow channel structure of the present invention, the flow channel structure is a 1-to-4 type flow channel structure, that is, the fluid distribution area 2 includes a first main flow channel 21 and four branch flow channels 22 perpendicularly connected to the first main flow channel 21. The four branch flow channels 22 are respectively a first branch flow channel, a second branch flow channel, a third branch flow channel, and a fourth branch flow channel arranged sequentially along the flow direction of the circulating fluid. The width of the first main flow channel 21 and the four branch flow channels 22 is 1 mm, and the depth of the four branch flow channels is 1 mm. A first flow channel ridge is formed between the first and second branch flow channels, a second flow channel ridge is formed between the second and third branch flow channels, and a third flow channel ridge is formed between the third and fourth branch flow channels. The width of the first, second, and third flow channel ridges is 1 mm. Figure 14 As shown, the flow channel structure also includes a first guide element 71, a second guide element 72, and a third guide element 73. The first guide element 71, the second guide element 72, and the third guide element 73 are semi-cylindrical. The radius of the first guide element 71 (i.e., the protrusion height of the protrusion of the first guide element 71) is 0.3 mm. The center of the first guide element 71 is located in the extension direction of the centerline of the first branch flow channel (i.e., the protrusion of the first guide element 71 is located in the extension direction of the centerline of the first branch flow channel); the second guide element 72... The radius (i.e., the protrusion height of the protrusion of the second guide element 72) is 0.5 mm, the distance between the center of the second guide element 72 and the center line of the second branch channel (i.e., the distance between the protrusion of the second guide element 72 and the center line of the second branch channel) is 0.5 mm, the radius (i.e., the protrusion height of the third guide element 73) is 0.7 mm, and the distance between the center of the third guide element 73 and the center line of the third branch channel (i.e., the distance between the protrusion of the third guide element 73 and the center line of the third branch channel) is 1 mm. Based on the above flow channel structure, a corresponding geometric model is established in Comsol Multiphysics software. Through the above flow channel structure design method, the corresponding velocity distribution map and temperature distribution map are obtained in Comsol Multiphysics software, such as... Figure 15 As shown, the flow velocities at corresponding positions in the first, second, third, and fourth branches are the same, respectively. Figure 16 As shown, the temperatures at corresponding positions in the first, second, third, and fourth branch channels are all the same. That is, by providing the first guide element 71, the second guide element 72, and the third guide element 73, the fluid flow distribution in this 1-to-4 branch channel structure is made uniform.

[0100] Comparative Example 2

[0101] Reference Figure 7 and Figure 8As shown, the flow channel structure of Comparative Example 2 is a 1-to-4 type flow channel structure. The difference between Comparative Example 2 and the flow channel structure of Embodiment 2 is that the flow channel structure in Comparative Example 2 does not have guiding elements. Based on the flow channel structure of Comparative Example 2, a corresponding geometric model was established in Comsol Multiphysics software. Using the aforementioned flow channel structure design method, the corresponding velocity distribution map and temperature distribution map were obtained in Comsol Multiphysics software, as shown below. Figure 9 As shown, the flow velocities at corresponding positions in the first, second, third, and fourth branch channels increase sequentially, as follows: Figure 10 As shown, the temperatures at corresponding locations in the first, second, third, and fourth branch channels decrease sequentially. That is, the flow channel structure in Comparative Example 2 suffers from uneven fluid flow distribution.

[0102] A third aspect of the present invention provides an electrochemical reactor comprising two electrodes disposed opposite to each other, a membrane electrode disposed between the two electrodes, and a porous diffusion layer disposed between the electrodes and the membrane electrode, wherein the electrodes are provided with the aforementioned flow channel structure.

[0103] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A flow channel structure, characterized in that, include: The first main channel (21) is used for the inflow of circulating fluid; The second main channel is used to discharge the circulating fluid; as well as, Multiple branch channels (22), the two ends of which are respectively connected to the sides of the first main channel (21) and the second main channel; In this embodiment, a guide element is provided on the side of the first main channel (21) away from the inlet of the branch channel (22) extending toward the inlet of the branch channel (22) so that the flow rate of the circulating fluid diverted from the first main channel (21) to the multiple branch channels (22) is the same.

2. The flow channel structure according to claim 1, characterized in that, It also includes a channel ridge disposed between two adjacent branch channels (22).

3. The flow channel structure according to claim 2, characterized in that, The guide element is configured to correspond one-to-one with the flow channel ridge.

4. The flow channel structure according to claim 2, characterized in that, The two ends of the flow channel ridge are formed with arc-shaped chamfers.

5. The flow channel structure according to claim 3, characterized in that, The branch channel (22) is vertically connected to the first main channel (21). The multiple branch channels (22) have the same width, the multiple channel ridges have the same width, and the guide element has a protrusion at the maximum length extending toward the inlet of the branch channel (22).

6. The flow channel structure according to claim 5, characterized in that, The protrusion height of the protrusion is 0-0.8 times the width of the first main channel (21).

7. The flow channel structure according to claim 6, characterized in that, When there are multiple guide elements, the protrusion height of the protrusion gradually increases along the flow direction of the circulating fluid in the first main channel (21).

8. The flow channel structure according to claim 7, characterized in that, Along the direction of the circulating fluid flow, the protrusion height of the protrusion increases sequentially in an arithmetic sequence.

9. The flow channel structure according to claim 5, characterized in that, The protrusion is positioned between the center line of the corresponding branch channel (22) and the center line of the adjacent channel ridge.

10. The flow channel structure according to claim 9, characterized in that, The distance between the protrusion and the centerline of the corresponding branch channel (22) satisfies at least one of the following two conditions: In scenario one, there are two branch channels (22), one guide element, and the protrusion is located in the direction of the center line extension of the corresponding branch channel (22). In scenario two, the number of branch channels (22) is greater than two, and the distance between the nth protrusion along the direction of circulating fluid flow and the centerline of the corresponding nth branch channel (22) is: In the above formula, D1 is the width of the branch channel (22). D2 is the width of the flow channel ridge. N is the number of the branch channels (22). n is 1, 2, 3, ..., N-1.

11. The flow channel structure according to claim 5, characterized in that, The guide element is symmetrical about the vertical line perpendicular to the first main channel (21) where the protrusion is located.

12. The flow channel structure according to claim 11, characterized in that, The guide element is semi-cylindrical.

13. The flow channel structure according to any one of claims 1-12, characterized in that, It also includes a front flow channel (1) and a rear flow channel (5) located upstream of the first main flow channel (21) and downstream of the second main flow channel, respectively.

14. A flow channel structure design method, characterized in that, Includes the following steps: A geometric model is established in numerical simulation software according to the flow channel structure described in any one of claims 1-13; Input the initial conditions, boundary conditions, and physical property parameters of the circulating fluid; Determine the flow model; The geometric model is meshed; Simulation calculations were performed to obtain the flow field distribution in the geometric model; Based on the flow field distribution, adjust the position and shape of the guiding elements in the geometric model; Repeat the above steps until the flow field distribution is uniform; The flow channel structure is adjusted according to the placement and shape of the guide elements in the geometric model.

15. An electrochemical reactor, characterized in that, It includes an electrode plate having a flow channel structure according to any one of claims 1-13.

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