Gradient flow equalizing type flow cell flow channel frame for optimizing electrolyte distribution

Abstract

The invention provides a flow cell runner frame for optimizing electrolyte distribution in a gradually-changing flow-equalizing manner, and belongs to the technical field of energy storage cells. The flow cell flow channel frame comprises a hollow frame body of a rectangular structure, a hollow area is a reaction electrode preset area, an electrolyte flow channel and a flow channel opening which are the same in structure are arranged on the upper side and the lower side of the reaction electrode preset area respectively, and the electrolyte flow channel communicates the flow channel opening with the reaction electrode preset area; and the electrolyte flow channel comprises a main flow channel, a shunting flow channel, a diffusion area and a rectification flow channel which are sequentially communicated from the flow channel opening to the reaction electrode preset area. In combination with the configuration theory and the generalized Merry law, the flow pressure loss of the electrolyte is reduced by optimizing the size parameters of the frame body flow channel and the layout design of the flow diffusion structure, the uniformity of hydraulic parameters of the electrolyte in the flow diffusion area, the rectification flow channel and the reaction electrode preset area is improved, and the flow diffusion effect is improved. And thus, performance parameters such as energy efficiency of the flow battery are improved. And aiming at electrolytes with different properties, the on-way resistance loss of the electrolytes can be effectively reduced, and the purposes of efficiency improvement and consumption reduction are achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of energy storage batteries, and particularly relates to a flow channel frame for a flow battery. Background Technology

[0002] With fossil fuels becoming increasingly depleted, developing renewable energy, optimizing the energy consumption structure, increasing the proportion of renewable energy in energy consumption, and ultimately replacing fossil fuels are the current directions for new energy development. Flow batteries, as a large-scale energy storage technology, use a pump to drive the electrolyte in a storage tank into the stack. The electrolyte is then guided by the flow channels inside the stack to porous electrodes for redox reactions, achieving the storage and release of electrical energy. Current flow channel frames typically adopt a long, straight configuration (horizontal or vertical arrangement), with multiple large-curvature corners within the flow channel. As the frame size increases, these geometrically abrupt locations easily induce angular vortices and backflow zones. Furthermore, as a key area for electrolyte introduction into the porous electrodes, the design of the flow channel directly affects the spatial uniformity of hydraulic parameters (flow rate and pressure, etc.) and internal mass transfer of the electrolyte in the electrode reaction zone. Specifically, the enlargement of the flow channel frame amplifies the differences in length, cross-section, and local resistance among the various branch channels, resulting in uneven electrolyte flow distribution. This creates a non-uniform velocity field where high-speed short-circuit regions and low-speed stagnation regions coexist, easily leading to local concentration polarization and weakening the overall battery performance. Therefore, how to rationally design the internal flow channels of a flow battery to improve the uniformity of the hydraulic parameters of the electrolyte flow through the carbon felt, thereby improving the energy efficiency and other performance parameters of the flow battery, is a major problem that urgently needs to be solved for the commercialization of flow batteries.

[0003] Patent publication number CN118136876A discloses a flow battery channel frame, including a flow frame body; an electrode area is provided in the middle of the flow frame body; two electrolyte flow channels are provided on both sides of the electrode area in a centrally symmetrical manner; the electrolyte flow channels include a main flow channel, a guide flow channel and multiple branch flow channels connected in sequence; one end of the main flow channel is provided with an electrolyte inlet and outlet; a primary branch port is provided between the main flow channel and the guide flow channel; a secondary branch port is provided between the guide flow channel and the branch flow channels; a tertiary branch port is provided between the branch flow channels and the electrode area; each branch port is comb-shaped; the longitudinal cross-sectional area A of the main flow channel, the guide flow channel and the branch flow channels is the same; the total flow cross-sectional area of ​​the primary branch port is K·A, the total flow cross-sectional area of ​​the secondary branch port is K2·A, and the total flow cross-sectional area of ​​the tertiary branch port is K3·A, and the value of K is in the range of 1.05-1.5. Patent publication number CN116154207A discloses a flow channel for a flow battery. The flow channel is integrally formed on a flow frame. The flow channel includes an inlet flow channel communicating with an inlet and an outlet flow channel, both located on either side of the flow frame. The inlet flow channel includes a main inlet channel, a first-stage equal-division inlet channel, and a second-stage equal-division inlet channel, all connected in sequence. The outlet flow channel also includes a main outlet channel, a first-stage equal-division outlet channel, and a second-stage equal-division outlet channel, all connected in sequence. A first Tesla valve is provided at the inlet end of the main inlet channel and the outlet end of the main outlet channel. The Tesla valve at the inlet impedes fluid flow, increasing the pressure drop of the fluid within each layer of the flow frame, further achieving uniform fluid flow across each layer. The Tesla valve at the inlet also allows for backflow of the liquid, enabling better mixing of the bromine complex with the electrolyte. Although the aforementioned patents have made beneficial attempts to improve the uniformity of electrolyte flow and enhance the mixing effect through multi-stage diversion structure optimization and Tesla valve-assisted regulation, there are still technical problems in practical applications, especially in large-scale flow battery stack scenarios, such as insufficient microscopic penetration uniformity, poor full-scale flow resistance matching, and poor balance between energy consumption and performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a flow battery channel frame with a gradually equalizing flow distribution to optimize electrolyte distribution. This structure mainly divides the flow channel along the overall electrolyte flow direction into several independent flow distribution units. Each unit is further subdivided into parallel microchannel clusters. Through the coordinated matching of "flow channel size and hydraulic parameters", the flow rate, pressure, etc. are kept highly consistent in space, thereby improving battery performance.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A flow battery channel frame with a gradually equalizing electrolyte distribution includes a rectangular hollow frame, the hollow region of which is a pre-positioned reaction electrode area, preferably a rectangular through-hole for accommodating the electrode and electrolyte; an electrolyte flow channel and a flow channel inlet with the same structure are arranged on the upper and lower sides of the pre-positioned reaction electrode area, and the electrolyte flow channel connects the flow channel inlet to the pre-positioned reaction electrode area; the electrolyte flow channel includes a main flow channel, a branch flow channel, a diffuser zone, and a rectifying flow channel that are sequentially connected from the flow channel inlet to the pre-positioned reaction electrode area; the diffuser zone includes two identical sub-regions, in which several isolated island-shaped diffuser structures are arranged in an array; the rectifying flow channel is divided into several rectifying channels by uniformly distributed strip-shaped rectifying columns spaced apart in the middle.

[0006] The electrolyte flow channels have the same depth, and the cross-sections of the main flow channel, branch flow channels, rectifying flow channels, and the minimum flow passage between each island-shaped diffuser structure are all rectangular.

[0007] The equivalent hydraulic diameter of the main channel section is d1, the equivalent hydraulic diameter of the branch channel section is d2, and the equivalent hydraulic diameter of the straightening channel section is d3. The relationship between the equivalent hydraulic diameters of each section follows d1. 3 = 2d2 3 =N·d3 3 Wherein, the equivalent hydraulic diameter d = 4A / P, where A is the cross-sectional area of ​​the channel perpendicular to the direction of electrolyte flow, P is the perimeter of the cross-section, and N is the number of rectifier channels.

[0008] The flow battery flow channel frame of this invention not only features centrally symmetrical electrolyte flow channels on both sides of the pre-positioned reaction electrode area, but also proposes a "diversion-coordination" gradually changing flow equalization structure. This divides the electrolyte flow channel into a main flow channel, a diversion flow channel, a diffusion zone, and a rectifying flow channel. The cross-sectional dimensions of each channel are determined according to Murray's law, thereby reducing the frictional resistance of the electrolyte flow. In the coupled configuration of the gradually changing flow channel and the diffusion zone, the diffusion zone acts as a pressure equalization cavity, ensuring that the inlet of the rectifying flow channel receives a laminar fluid with a highly consistent distribution of hydraulic parameters. This weakens concentration polarization caused by velocity differences, enabling the electrode active sites to simultaneously participate in the redox reaction, ultimately improving the energy efficiency and capacity retention of the flow battery. Furthermore, the positive and negative electrode flow channel frames adopt a completely symmetrical "multi-stage boss" design, achieving standardization of frame components and significantly reducing the number of molds and processing costs.

[0009] The electrolyte channels on the upper and lower sides of the pre-positioned area of ​​the reaction electrode are divided into an inlet channel and an outlet channel, and the channel openings are divided into an inlet channel opening and an outlet channel opening. The inlet channel and the outlet channel are centrally symmetrical about the center point of the pre-positioned area of ​​the reaction electrode, and the inlet channel opening and the outlet channel opening are diagonally distributed relative to the hollow frame.

[0010] A buffer zone is provided between the main flow channel and the flow channel opening; the buffer zone adopts a streamlined design with a gradually changing curvature. The introduction of the buffer zone prolongs the residence time of the electrolyte in the main flow channel and reduces the shear erosion at the locations of abrupt changes in cross-section.

[0011] A primary diversion section is provided between the main flow channel and the diversion channel; a secondary diversion section is provided between the diversion channel and the dispersion zone; both the primary and secondary diversion sections are expansion-type "trumpet mouths" with a radius of curvature of 3-5 mm for their inner wall arcs.

[0012] The primary flow divider is located on the central axis of the hollow frame, at the point where the distance from the inlet or outlet of the liquid flow channel to the corresponding edge of the pre-placed reaction electrode area is divided into four equal parts. A separate island-shaped diffuser structure is located at the "mouth" of the primary flow divider, dividing the diffuser area from the central axis into two sub-regions, thus forming two flow channels and two secondary flow dividers. The primary and secondary flow dividers decelerate the electrolyte through localized expansion, suppressing turbulent pulsation while simultaneously converting the dynamic and static pressures of the fluid. This reduces the spatial gradient between the velocity and pressure fields, allowing for a uniform distribution of the hydrodynamic parameters of the electrolyte in the diffuser area. After rectification, the electrolyte flows evenly to every region of the electrode, thereby reducing the extent of the flow dead zone and improving the performance of the flow battery.

[0013] The two diversion channels and two secondary diversion sections are distributed in a mirror-symmetric manner about the central axis of the hollow frame. The two secondary diversion sections have the same shape and size. The island-shaped diffuser structures in the two sub-regions of the diffuser zone have the same shape and size.

[0014] The island-shaped diffuser structure is a triangular prism or / and a quadrangular prism, and the minimum surface spacing between two adjacent island-shaped diffuser structures is 1-3 mm.

[0015] Preferably, island-shaped diffusion structures are evenly arranged longitudinally in the diffusion zone according to the principle of dividing into three equal parts; the island-shaped diffusion structures are triangular prisms and quadrangular prisms, and the distance between two adjacent triangular prisms and the distance between the triangular prisms and quadrangular prisms are 1-3 mm, so that after the electrolyte is divided, mass transfer homogenization can be achieved in the diffusion zone, and then enter the reaction electrode pre-positioning area with a highly consistent velocity field, significantly improving the utilization rate of the active area.

[0016] The hollow frame is provided with mounting holes and electrolyte passage holes.

[0017] Preferably, each of the four corners of the flow channel frame is provided with a mounting hole. During assembly, two flow battery flow channel frames are used. A positive carbon felt electrode is mounted on one flow battery flow channel frame, and a negative carbon felt electrode is mounted on the other flow battery flow channel frame. Then, the two flow battery flow channel frames are fixed together through the mounting holes to form a battery unit.

[0018] The beneficial effects of this invention are: (1) The present invention satisfies d1 by limiting the equivalent hydraulic diameter of the main channel, the branch channel, and the straightening channel. 3 = 2d2 3 =N·d3 3 By matching the flow channel dimensions with the rectangular cross-section of each channel, the flow channel size and electrolyte hydraulic parameters are precisely adapted, inducing a synergistic effect of "large-area laminar flow-local turbulence": a smooth laminar flow is formed in the main flow channel and the branch flow channel, which significantly reduces the electrolyte flow pressure loss and energy dissipation; the array-type island-shaped flow diffusion structure (triangular prism, quadrangular prism or combination thereof) and the straightening flow channel induce local micro-vortex turbulence, thereby enhancing the mass transfer efficiency between the electrolyte and the electrode surface in the downstream reaction zone, avoiding the formation of reaction dead zones, and thus improving the energy conversion efficiency of the flow battery.

[0019] (2) This invention utilizes a multi-stage, gradually changing flow channel structure consisting of a main flow channel, a branch flow channel, a diffusion zone, and a rectifying flow channel. Combined with the "pressure equalization chamber" effect formed by the double-symmetric sub-regions of the diffusion zone, the electrolyte pressure is homogenized after two flow divisions. Furthermore, the rectifying flow channel is divided into several uniform rectifying channels by strip-shaped rectifying columns, ensuring that the electrolyte covers the entire reaction electrode pre-positioning area with a uniform and stable flow rate. This design effectively eliminates the flow rate gradient and pressure imbalance problems existing in existing flow channels, significantly reduces concentration polarization, ensures that more reaction sites in the reaction electrode pre-positioning area participate in the redox reaction simultaneously, and improves the utilization rate of electrode active materials and battery power density.

[0020] (3) The design of the inlet and outlet channels being centrally symmetrical about the center point of the reaction electrode pre-positioning area and the channel openings being diagonally distributed ensures the consistency of the residence time of the electrolyte in the reaction electrode pre-positioning area and avoids electrode erosion corrosion caused by excessive local flow velocity. At the same time, the rectangular cross-section of each channel, the reasonable curvature radius of the expansion split section, and the streamlined buffer design reduce flow resistance and eddy current loss, reduce stress concentration and impurity deposition in the channel, and improve the stability of the channel frame structure and the long-term cycle life of the battery.

[0021] (4) Through the synergistic effect of "parameter matching-flow regulation-uniform distribution enhancement", this invention simultaneously achieves "low flow loss, high mass transfer efficiency and excellent flow field uniformity", effectively solving the technical pain point that the flow uniformity and flow resistance characteristics of the existing flow channel frame are difficult to balance. This enables the flow battery to achieve comprehensive improvement in core performance such as charge and discharge efficiency, power density and cycle stability, and provides reliable structural support for its large-scale engineering application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a structural diagram of the flow channel frame; In the figure, 1 is the reaction electrode pre-positioning area; 2 is the liquid inlet; 3 is the liquid outlet; 4 is the main flow channel; 5 is the branch flow channel; 6 is the diffusion zone; 7 is the rectification flow channel; 8 is the electrolyte passage hole; 101 is the buffer zone; 201 is the primary branch section; 301 is the secondary branch section; and 401 is the mounting hole.

[0024] Figure 2 The mass flow rate distribution at the rectifier channel inlet is shown as a comparative example after simulation testing.

[0025] Figure 3 The mass flow rate distribution diagram at the rectifier channel inlet after simulation test for the implementation case. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1 A flow battery flow channel frame with gradually equalized flow distribution for optimizing electrolyte distribution, structure as follows: Figure 1 As shown, the device includes a rectangular hollow frame with a rectangular reaction electrode pre-positioning area 1 in the center. Identical liquid inlet and outlet channels are respectively located on the upper and lower sides of the reaction electrode pre-positioning area 1. The liquid inlet channel is connected to the liquid inlet port 2 located at the upper left corner of the frame, and the liquid outlet channel is connected to the liquid outlet port 3 located at the lower right corner of the frame. The two channels are centrally symmetrical about the center point of the reaction electrode pre-positioning area 1.

[0028] The electrolyte flow channel (taking the inlet flow channel as an example) includes, from the inlet to the reaction zone, the following in sequence: main flow channel 4, branch flow channel 5, diffusion zone 6, and rectifier flow channel 7.

[0029] Specifically, the main flow channel 4 is a straight channel directly connected to the liquid inlet 2; the branch flow channel 5 is formed by two parallel flow channels after the main flow channel 4 is branched once; the diffuser zone 6 is located at the end of the branch flow channel 5, and multiple isolated island-shaped diffuser structures are arranged in an array inside; the rectifier flow channel 7 is located between the diffuser zone 6 and the reaction electrode pre-positioning zone 1, and parallel strip-shaped rectifier columns are provided inside to divide the flow channel into a specific number of rectifier channels of the same size.

[0030] All flow channels have a uniform depth. The cross-sections of the main flow channel 4, branch flow channel 5, and straightening flow channel 7, as well as the minimum flow cross-section between adjacent island-shaped flow diffusers in the diffuser zone 6, are all rectangular. Based on Murray's law for fluid transport optimization, the cross-sectional dimensions of each flow channel are designed. The equivalent hydraulic diameter of the main flow channel 4 is d1, the equivalent hydraulic diameter of the branch flow channel 5 is d2, and the equivalent hydraulic diameter of the straightening flow channel 7 is d3. The relationship between the equivalent hydraulic diameters of each cross-section follows d1. 3 =2d2 3 =N·d3 3 Wherein, the equivalent hydraulic diameter d = 4A / P, where A is the cross-sectional area of ​​the channel perpendicular to the direction of electrolyte flow, P is the perimeter of the cross-section, and N is the number of rectifier channels.

[0031] This design significantly reduces the frictional resistance of the electrolyte flow in the flow channel network, minimizing pressure loss from the inlet to the reaction zone inlet. After being split and homogenized, the electrolyte finally enters the reaction electrode pre-positioning zone 1 through the rectifying channel 7 in a laminar flow state with highly uniform flow velocity, effectively weakening concentration polarization and improving the overall performance of the battery.

[0032] Finally, the electrolyte flowing out through the rectifier channel 7 can uniformly enter the reaction electrode pre-positioning area 1 in a laminar flow state with a highly consistent distribution of hydraulic parameters, which significantly reduces the concentration polarization caused by the difference in flow rate and improves the utilization rate of the electrode active sites.

[0033] In addition, a mounting hole 401 is provided at each of the four corners of the hollow frame to align and fix the two completely symmetrical flow channel frames of the positive and negative electrodes to form a complete battery unit, thereby realizing the standardization of frame parts and reducing processing costs.

[0034] Example 2 A flow battery flow channel frame with gradually equalized flow distribution for optimizing electrolyte distribution, structure as follows: Figure 1As shown, the device includes a hollow frame with a rectangular structure. The hollow area is the reaction electrode pre-positioning area 1. An electrolyte flow channel and a flow channel opening with the same structure are arranged on the upper and lower sides of the reaction electrode pre-positioning area 1. The electrolyte flow channel connects the flow channel opening to the reaction electrode pre-positioning area 1. The device is characterized in that the electrolyte flow channel includes a main flow channel 4, a branch flow channel 5, a flow diffusion area 6, and a rectification flow channel 7 that are connected sequentially from the flow channel opening to the reaction electrode pre-positioning area 1. The flow diffusion area 6 includes two identical sub-regions, in which several isolated island-shaped flow diffusion structures are arranged in an array. The rectification flow channel 7 is divided into several rectification channels by uniformly distributed strip-shaped rectification columns at intervals.

[0035] The electrolyte channels on the upper and lower sides of the reaction electrode pre-positioning area 1 are divided into an inlet channel and an outlet channel. The channel openings are divided into an inlet channel opening 2 and an outlet channel opening 3. The inlet channel and the outlet channel are centrally symmetrical about the center point of the reaction electrode pre-positioning area 1. The inlet channel opening 2 and the outlet channel opening 3 are diagonally distributed relative to the hollow frame.

[0036] The electrolyte flow channels have the same depth, and the cross-sections of the main flow channel 4, the branch flow channel 5, the rectifier flow channel 7, and the minimum flow passage between each island-shaped diffuser structure are all rectangular.

[0037] Specifically, a streamlined buffer zone 101 with a gradually changing curvature is set at the connection between the main flow channel 4 and the inlet flow channel 2. This design can mitigate the direct impact of electrolyte flowing in at high speed from the inlet to the inlet of the main flow channel 4, prolong the residence time of the fluid in this area, and initially stabilize the flow state.

[0038] The primary diversion section 201 and the secondary diversion section 301 are located at the junction of the main flow channel 4 and the two diversion channels 5; the secondary diversion section 301 is located at the junction of each diversion channel 5 and the dispersion zone 6. Both diversion sections are designed as expanding "funnel mouths" with a specific radius of curvature on their inner walls.

[0039] At the center of the "funnel" of the primary diversion section 201, an independent quadrangular prism-shaped island-like diffuser structure is set up. This structure not only naturally divides the diffuser zone 6 into two completely symmetrical sub-regions, but also guides the fluid to smoothly divert to both sides.

[0040] After smoothly entering the main flow channel 4 via buffer zone 101, the electrolyte flows to the primary branching section 201. In the "funnel" region, the channel cross-sectional area expands, the flow velocity decreases, and some dynamic pressure is converted into static pressure, suppressing turbulence. After being guided by the central island structure, the electrolyte is evenly distributed into the two branching channels 5. Subsequently, the electrolyte is further diffused and decelerated through the secondary branching section 301 before entering the diffuser zone 6. The array-like island-shaped diffuser structure in the diffuser zone 6 thoroughly disturbs and mixes the fluid, making its pressure and velocity distribution more uniform in space. Finally, the highly homogenized fluid forms a stable laminar flow through the rectifying channel 7, covering the entire reaction electrode pre-positioned area 1. This design further reduces the flow dead zone, ensuring full utilization of the electrode active area.

[0041] Within the two sub-regions of diffuser zone 6, a mixture of triangular and quadrangular prisms is used. These diffuser structures are evenly spaced according to the principle of longitudinal equal division. The minimum spacing between adjacent diffuser structures is precisely controlled within a small and consistent range. This dimension ensures that the flow channel has a sufficient hydraulic diameter to reduce resistance, while also effectively cutting and reorganizing the fluid at the microscale.

[0042] Different shapes of diffusion structures induce varying disturbance patterns and intensities in the fluid. The sharp edges of a triangular prism facilitate fluid segmentation and the generation of micro-vortices, promoting mass exchange; while the parallel walls of a quadrangular prism help guide and stabilize streamlines. The combination of these two creates a more complex "synergistic diffusion" field, causing the electrolyte to be repeatedly segmented, mixed, and redistributed at the microscale, achieving unprecedented mass transfer homogenization. The electrolyte treated in this way exhibits a highly consistent velocity and concentration field before entering the rectifying channel 7, allowing it to enter the reaction electrode pre-positioning zone 1 in a near-ideal state. This maximizes the synchronous participation of electrode active sites in the reaction, significantly improving the energy efficiency and capacity retention of the flow battery.

[0043] In addition, mounting holes 401 are provided at the four corners of the hollow frame. The positive and negative flow channel frames can adopt this completely symmetrical design. By aligning and fastening the mounting holes 401, the parts are made universal, which greatly reduces the mold cost and assembly complexity.

[0044] Example 3 A flow battery flow channel frame with gradually equalized flow distribution for optimizing electrolyte distribution, structure as follows: Figure 1As shown, the hollow frame adopts a rectangular structure with a thickness of 3mm. It is made of polyvinyl chloride (PVC), which combines resistance to electrolyte corrosion, economical processing, and structural strength. It is integrally molded using injection molding to ensure structural consistency. The hollow area is a rectangular through-hole used to accommodate the carbon felt electrode (its size is perfectly matched to the reaction electrode pre-positioned area 1) and the electrolyte. The electrode is attached to the bottom of the flow channel. Each of the four corners of the hollow frame has a mounting hole 401 for fixing and assembling the positive and negative electrode flow channel frames. The positive and negative electrode flow channel frames have completely identical structures, achieving parts standardization and reducing mold opening costs.

[0045] An identical electrolyte flow channel and flow port are arranged on the upper and lower sides of the reaction electrode pre-positioning area 1. The flow port is a circular through hole. The flow ports on the upper and lower sides are diagonally distributed relative to the hollow frame (the upper left corner is the liquid inlet flow port 2, and the lower right corner is the liquid outlet flow port 3). The depth of all flow channels is consistent with the depth of the reaction electrode pre-positioning area 1. The longitudinal section of the flow channel cross section and the minimum flow spacing between the diffuser structure is uniformly rectangular to ensure the stability of the flow field.

[0046] A streamlined buffer zone 101 is added between the main channel 4 and the flow channel inlet, smoothly connecting the inlet and the flow channel inlet, and transitioning the outlet to the main channel 4, extending the electrolyte residence time and reducing shear scouring at the abrupt change in cross-section. The main channel 4 extends from the buffer zone 101 to the primary diversion section 201, with a rectangular cross-section and an equivalent hydraulic diameter of 4 mm. The primary diversion section 201 is located on the central axis of the hollow frame, at the quartering point between the inlet flow channel 2 and the corresponding edge of the reaction electrode pre-positioned area 1. It is an expanding "funnel mouth" with an inner wall arc curvature radius of 3 mm, achieving initial deceleration and pressure equalization of the electrolyte through local expansion.

[0047] The diversion channel 5 is divided into two sections by the primary diversion section 201. These sections are mirror-symmetrical about the central axis of the hollow frame, with rectangular cross-sections and an equivalent hydraulic diameter of 3mm, satisfying the flow distribution relationship derived from Murray's Law. The secondary diversion section 301 is located between the diversion channel 5 and the diffusion zone 6. It is also an expanding "funnel mouth" with an inner wall curvature radius of 5mm. Its structure is symmetrical and its dimensions match those of the primary diversion section 201, further achieving electrolyte deceleration and pressure homogenization.

[0048] The diffuser region 6 is divided into two symmetrical sub-regions by a single island-shaped diffuser structure at the primary diversion section 201. The island-shaped diffuser structures are evenly spaced longitudinally according to the principle of trisection. Triangular prisms (equilateral triangle cross-section) and square prisms (square cross-section) are arranged in the two sub-regions. The lateral spacing of the island-shaped structures is 2 mm, and the minimum spacing between adjacent structure surfaces is 2 mm, forming a pressure equalization cavity effect, while inducing local micro-vortex turbulence to enhance mass transfer.

[0049] The rectifier channel 7 is equipped with evenly distributed strip-shaped rectifier columns, which are divided into 121 rectifier channels. Each rectifier channel has an equivalent hydraulic diameter of 2mm, achieving optimal flow distribution.

[0050] The positive and negative carbon felt electrodes are respectively embedded into the reaction electrode pre-positioning area 1 of two identical flow channel frames, ensuring that the electrodes are deeply fitted to the bottom of the flow channel without gaps; the two flow channel frames are aligned so that the liquid inlet 2, liquid outlet 3 and mounting hole 401 correspond one-to-one; stainless steel bolts are inserted through the mounting holes 401 at the four corners and tightened with nuts to form a complete battery unit. After assembly, the overall sealing is good and there is no risk of electrolyte leakage.

[0051] The electrolyte flows in from the inlet 2, smoothly transitions to the main flow channel 4 via the streamlined buffer zone 101, and is then transported to the primary diversion section 201 where it is divided into two streams, entering two symmetrical diversion channels 5. After further expansion and pressure equalization in the secondary diversion section 301, the electrolyte enters the diffusion zone 6, where it achieves uniform flow and mass dissipation through alternating triangular and quadrangular prism structures, forming a synergistic flow pattern of "large-area laminar flow - local turbulent flow". Finally, it is evenly covered by 12 rectifier channels in the pre-placed reaction electrode area 1, ensuring full contact with the electrode to complete the oxidation-reduction reaction. The electrolyte after the reaction flows out from the outlet 3.

[0052] Comparative Example The difference from Example 3 is that the width of the main flow channel 4 is 4 mm, the spacing of the flow diffusion structures in the flow diffusion region 6 is 9 mm, and the width of the flow straightening channel 7 is 4 mm. All other structures are exactly the same.

[0053] The flow battery flow channel frame described in Example 3 and the comparative example was simulated, and the basic test parameters are shown in the table below: Simulation results are shown below Figure 2 (Example 3) and Figure 3 (Comparative Example). The bar charts for each battery cell in the figure correspond to the mass flow rates of the seven ports of different rectifier channels on the flow channel frame. Comparing the two figures reveals that... Figure 3 The mass flow rate distribution at the third-stage diversion port is more uniform; this proves that the flow cell flow channel frame with a gradual flow equalization structure of this application can improve the uniformity of the hydraulic parameters of the electrolyte flowing through the reaction electrode pre-positioning area.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flow cell channel frame for gradually equalizing electrolyte distribution, comprising a rectangular hollow frame, the hollow region being a reaction electrode pre-positioning area (1), wherein an electrolyte flow channel and a flow channel opening of identical structure are arranged on the upper and lower sides of the reaction electrode pre-positioning area (1), the electrolyte flow channel connecting the flow channel opening to the reaction electrode pre-positioning area (1); characterized in that, The electrolyte flow channel includes a main flow channel (4), a branch flow channel (5), a diffuser zone (6), and a rectifier flow channel (7) that are connected sequentially from the flow channel opening to the reaction electrode pre-positioning area (1); the diffuser zone (6) includes two identical sub-regions, and several isolated island-shaped diffuser structures are arranged in an array in the sub-regions; the rectifier flow channel (7) is provided with uniformly distributed strip-shaped rectifier columns at intervals, dividing it into several rectifier channels.

2. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 1, characterized in that, The electrolyte channels on the upper and lower sides of the reaction electrode pre-positioning area (1) are divided into an inlet channel and an outlet channel. The channel openings are divided into an inlet channel opening (2) and an outlet channel opening (3). The inlet channel and the outlet channel are centrally symmetrical about the center point of the reaction electrode pre-positioning area (1). The inlet channel opening (2) and the outlet channel opening (3) are diagonally distributed relative to the hollow frame.

3. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 2, characterized in that, The electrolyte flow channels have the same depth, and the cross-sections of the main flow channel (4), branch flow channel (5), and rectifier flow channel (7), as well as the cross-section of the minimum flow passage between each island-shaped diffuser structure, are all rectangular.

4. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 3, characterized in that, The equivalent hydraulic diameter of the main channel (4) is d1, the equivalent hydraulic diameter of the branch channel (5) is d2, and the equivalent hydraulic diameter of the straightening channel (7) is d3. The relationship between the equivalent hydraulic diameters of each channel follows d1. 3 =2d2 3 =N·d3 3 Wherein, the equivalent hydraulic diameter d = 4A / P, where A is the cross-sectional area of ​​the channel perpendicular to the direction of electrolyte flow, P is the perimeter of the cross-section, and N is the number of rectifier channels.

5. The flow cell flow channel frame with gradually varying flow-equalizing electrolyte distribution according to claims 1-4, characterized in that, A buffer zone (101) is provided between the main channel (4) and the channel opening; the buffer zone (101) adopts a streamlined design with gradually changing curvature.

6. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 5, characterized in that, A primary diversion section (201) is provided between the main flow channel (4) and the diversion channel (5); a secondary diversion section (301) is provided between the diversion channel (5) and the dispersion area (6); both the primary diversion section (201) and the secondary diversion section (301) are expansion-type "trumpet mouths" with a radius of curvature of 3-5 mm for their inner wall arcs.

7. The flow cell flow channel frame with gradually varying flow equalization and optimized electrolyte distribution according to claim 6, characterized in that, The primary diversion section (201) is located on the central axis of the hollow frame and at the point where the distance from the liquid inlet (2) or liquid outlet (3) to the corresponding edge of the reaction electrode prepositioning area (1) is divided into four equal parts. A separate island-shaped diffuser structure is provided at the "mouth" of the primary diversion section (201) to divide the diffuser area (6) from the central axis into two sub-regions, thereby forming two diversion channels (5) and two secondary diversion sections (301).

8. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 7, characterized in that, The two diversion channels (5) and the two secondary diversion sections (301) are distributed in a mirror symmetry about the central axis of the hollow frame. The two secondary diversion sections (301) have the same shape and size. The island-shaped diffuser structures in the two sub-regions of the diffuser area (6) have the same shape and size.

9. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 8, characterized in that, The island-shaped diffuser structure is a triangular prism or / and a quadrangular prism, and the minimum surface spacing between two adjacent island-shaped diffuser structures is 1-3 mm.

10. The flow cell channel frame for gradually equalizing electrolyte distribution according to claim 1, characterized in that, The hollow frame is provided with mounting holes (401) and electrolyte passage holes (8).

Images